A COMPREHENSIVE GUIDE ON DIFFERENT TYPES OF PRIMARY & SECONDARY BATTERIES,VARIETY OF LITHIUM-ION BATTERIES AND BATTERIES OF THE FUTURE NEW CHEMISTRIES
vijay tharad
Director Operations at Corporate Professional Academy for Technical Training & Career Development
What is a Battery?
A battery is a device that converts chemical energy into electrical energy by means of an electrochemical reduction and oxidation reaction (redox reaction). Batteries are used on a large scale in various industries.
The image above shows the basic components of a battery.
The three major components of a battery are
Types of Battery Cells
There are two main types of batteries, which are
Let us learn about each type in brief.
Primary Battery
Primary batteries are also known as disposable batteries. In this type of battery, the electrochemical reaction is not reversible. The electrochemical energy is produced by the continuous decomposition of the electrode material and once it is completely used up, the electrode breaks. This process is irreversible and hence should be replaced by a new battery. Batteries ranging from coin cells to AA batteries are all a part of the primary battery.
There are two more basic types of primary battery:
Alkaline Battery
An alkaline battery gets its name due to the presence of an alkaline electrolyte mostly made up of potassium hydroxide (KOH). The image above represents a general diagram of an alkaline battery.
Alkaline batteries are generally used in remotes, digital cameras, toys, flashlights etc.
Dry Cell
Carl Gassner patented a variant of a Leclanche cell, which came to be known as the dry cell because it does not have a free liquid electrolyte.
Let us take an overview of the dry cell battery:
These are generally used in hearing aid applications, watches, calculators, etc.
Secondary Battery
Secondary Batteries are those whose chemical reactions can be reversed with a certain amount of voltage to the battery. In simple words, these batteries can be recharged.
There are three types of secondary batteries.
Let us learn about each type in brief.
Lead Acid
Lead acid batteries can be bought at a reasonable cost and are used in some heavy-duty appliances.
They generally are larger in size and heavy. They are used in devices like huge solar panels, cars or for backup power stations.
Nickel Metal Hydride Batteries
It is another type of rechargeable battery. The chemical reaction at the positive electrode is very similar to the nickel-cadmium cell.
Presently the nickel-cadmium batteries resemble a jelly roll with a porous anode and cathode plates, with a separator in between.
Nickel Iron Battery
Nickel Iron batteries were initially used for the first electric car. It is also known as the Edison battery.
These are generally used in railway vehicles, subways, fuel-cell cars etc.
Advantages of Primary Batteries
Primary batteries, also known as non-rechargeable batteries, tend to get overshadowed by the media attention secondary or rechargeable batteries receive. Heavy focus on one product over another may convince folks that primary batteries are old technology on the way out. Not so.
Primaries play an important role, especially when charging is impractical or impossible, such as in military combat, rescue missions and forest-fire services. Regulated under IEC 60086, primary batteries also service pacemakers in heart patients, tire pressure gauges in vehicles, smart meters, intelligent drill bits in mining, animal-tracking, remote light beacons, as well as wristwatches, remote controls, electric keys and children’s toys.
Most implantable pacemaker batteries are lithium-based, draw only 10–20 microamperes (μA) and last 5–10 years. Many hearing aid batteries are also primary with a capacity from 70–600mAh, good for 5–14 days before a replacement is needed. The rechargeable version offers less capacity per size and lasts for about 20 hours. Cost-saving is the major advantage.
High specific energy, long storage times and instant readiness give primary batteries a unique advantage over other power sources. They can be carried to remote locations and used instantly, even after long storage; they are also readily available and environmentally friendly when disposed.
The most popular primary battery is alkaline. It has a high specific energy and is cost effective, environmentally friendly and leak-proof even when fully discharged. Alkaline can be stored for up to 10 years, has a good safety record and can be carried on an aircraft without being subject to UN Transport and other regulations. The negative is low load currents, limiting its use to light loads such as remote controls, flashlights and portable entertainment devices.
Moving into higher capacities and better loading leads to lithium-metal batteries. These have very strict air shipping guidelines and are subject to Dangerous Good Regulations involving Class 9 hazardous material.
Figure 1 compares the specific energy of lead acid, NiMH and Li-ion as secondary, as well as alkaline and lithium-metal as primary batteries.
figure 1 Specific energy comparison of secondary and primary batteries
Specific energy only indicates the capacity a battery can hold and does not include power delivery, a weakness with most primary batteries. Manufacturers of primary batteries publish specify specific energy; specific power is seldom published. While most secondary batteries are rated at a 1C discharge current, the capacity on consumer-grade primary batteries is measured with a very low current of 25mA. In addition, the batteries are allowed to discharge from the nominal 1.5V for alkaline to 0.8V before deemed fully discharged. This provides impressive readings on paper, but the results are less flattering when applying loads that draw higher currents.
Figure 2 compares the performance of primary and secondary batteries as “Rated” and “Actual.” Rated refers to the specific energy when discharging at a very low current; Actual discharges at 1C, the way most secondary batteries are rated. The figure clearly demonstrates that the primary alkaline performs well with light load typical to entertainment devices, while the secondary batteries represented by lead acid, NiMH and Li-ion have a lower rated capacity (Rated) but are better when being loaded with a 1C discharge (Actual).
Figure 2 Energy comparison under load
One of the reasons for low performance under load conditions is the high internal resistance of primary batteries, which causes the voltage to collapse. Resistance determines how well electrical current flows through a material or device and is measured in ohms (?). As the battery depletes on discharge, the already elevated resistance increases further. Digital cameras with primary batteries are borderline cases — a power tool on alkaline would be impractical. A spent alkaline in a digital camera often leaves enough energy to run the kitchen clock for two years.
Table 3 illustrates the capacity of standard alkaline batteries with loads that run typical personal entertainment devices or small flashlights.
Figure 3 Alkaline specifications
AA and AAA are the most common cell formats for primary batteries. Known as penlight batteries for pocket lights, the AA became available to the public in 1915 and was used as a spy tool during World War I; the American National Standards Institute standardized the format in 1947. The AAA was developed in 1954 to reduce the size of the Kodak and Polaroid cameras and shrink other portable devices. In the 1990s, an offshoot of the 9V battery produced the AAAA for laser pointers, LED penlights, computer styli and headphone amplifiers. (The 9V uses six AAAA in series.)
Table 4 compares common primary batteries.
Figure 4 Summmary of batteries available in AA and AAA format
The AA cell contains roughly twice the capacity of the smaller AAA at a similar price. This doubles the energy cost of the AAA over the AA. Energy cost often takes second stage in preference to downsizing. This is the case with bicycle lights where the AA format would only increase the size of the light slightly but could deliver twice the runtime for the same cost.
To cut cost, cities often consolidate purchases and this includes bulk acquisitions of alkaline batteries. A city the size of Vancouver, Canada, with about 600,000 citizens would buy roughly 33,000 AA, 16,000 AAA, 4,500 C and 5,600 D-size alkaline cells for general use.
Retail prices of the alkaline AA vary, so does performance. Exponent Inc. a US engineering firm, checked the capacity of eight brand-name alkaline batteries in AA packages and discovered an 800 percent discrepancy between the highest and lowest performers. The test standard was based on counting the shots of a digital camera until the batteries were depleted, a test that considered capacity and loading capability of a battery.
Figure 5 illustrates the number of shots a digital camera can take with discharge pulses of 1.3W using alkaline, NiMH and Lithium Li-FeS2 in an AA format. (With two cells in series at 3V, 1.3W draws 433mA.) The clear winner was Li-FeS2 (Lithium AA) with 690 pulses; the second was NiMH with 520 pulses, and the distant third was standard alkaline, producing only 85 pulses. Internal resistance rather than capacity governs the shot count.
Figure 5: Number of shots a digital camera can take with alkaline NiMH and lithium.
The relationship between battery capacity and current delivery is best illustrated with the Ragone Chart. Named after David V. Ragone , the Ragone chart evaluates an energy storage device on energy and power. Energy in Ah presents the available storage capacity of a battery that is responsible for the runtime; power in watts governs the load current.
Figure 6 illustrates the Ragone chart with the 1.3W load of a digital camera (indicated by the red arrow and dotted line) using lithium (Li-FeS2), NiMH and alkaline. The horizontal axis displays energy in Wh and the vertical axis provides power in watts. The scale is logarithmic to allow a wide selection of battery sizes.
Digital camera loads NiMH, Li-FeS2 and alkaline with 1.3W pulses according to ANSI C18.1 (dotted line). The results are:
Energy = Capacity x V Power = Current x V
The performance of the battery chemistries varies according to the position of the Ragone line. NiMH delivers the highest power and works well at high loads but it has the lowest specific energy. Lithium Li-FeS2 has the highest specific energy and satisfies moderate loading conditions, and alkaline offers an economic solution for lower current drains.
Summary
Primary batteries are practical for applications that draw occasional power, but they can get expensive when in continuous use. Price is a further issue when the packs are replaced after each mission, regardless of length of use. Discarding partially used batteries is common, especially in fleet applications and critical missions as it is convenient to simply issue fresh packs with each assignment rather than estimating the usage. At a battery conference a US Army general said that half of the batteries discarded still have 50 percent energy left.
The state-of-charge of primary batteries can be estimated by measuring the internal resistance. Each battery type needs its own look-up table as the resistive characteristics may differ. A more accurate method is coulomb counting that observes out-flowing energy, but this requires a more expensive circuit and is seldom done. – Coulomb Counting). This requires a more expensive circuit and is seldom done
Choices of Primary Batteries
Zinc-carbon, also known as carbon-zinc or the Leclanché battery, is one of the earliest and least expensive primary batteries. It delivers 1.5V and often come with consumer devices. The first zinc-carbon invented by Georges Leclache in 1859 was wet.
Alkaline. Alkaline-manganese, also known as alkaline, is an improved version of the zinc-carbon battery and delivers 1.5V. Lewis Urry (1927–2004) invented alkaline in 1949 while working with the Eveready Battery Company laboratory in, Ohio, USA.
Alkaline delivers more energy at higher load currents than zinc-carbon. Furthermore, a regular household alkaline provides about 40 percent more energy than the average Li-ion but alkaline is not as strong as Li-ion on loading. Alkaline has very low self-discharge and does not leak electrolyte when depleted as the old zinc-carbon does, but it is not totally leak-proof.
All primary batteries produce a small amount of hydrogen gas on discharge and battery-powered devices must make provision for venting. Pressure buildup in the cell can rupture the seal and cause corrosion. This is visible in form of a feathery crystalline structure that can develop and spread to neighboring parts in the device and cause damage.
Lithium iron disulfide (Li-FeS2) is a newcomer to the primary battery family and offers improved performance compared to alkaline. Lithium batteries normally deliver 3 volts and higher, but Li-FeS2 has 1.5 volts to be compatible with the AA and AAA formats. It has a higher capacity and a lower internal resistance than alkaline. This enables moderate to heavy loads and is ideal for digital cameras. Further advantages are improved low temperature performance, superior leakage resistance and low self-discharge, allowing 15 years of storage at ambient temperatures.
The disadvantages of the Li-FeS2 are a higher price and transportation issues due to the lithium metal content in the anode. In 2004, the US DOT and the Federal Aviation Administration (FAA) banned bulk shipments of primary lithium batteries on passenger flights, but airline passengers can still carry them on board if the allotted lithium content is not exceeded. Each AA-sized Li-FeS2 contains 0.98 grams of lithium; the air limitation of primary lithium batteries is 2 grams (8 grams for rechargeable Li-ion). This restricts each passenger to two cells, but exceptions have been made in which 12 sample batteries can be carried.
The Li-FeS2 includes safety devices in the form of a positive thermal coefficient (PTC) that limits the current at high temperature and resets when normal. The Li-FeS2 cell cannot be recharged as is possible with NiMH in the AA and AAA formats. Recharging, putting a cell in backwards, mixing in a depleted cell or adding a foreign cell could cause a leak or explosion.
Figures 1 and 2 compare the discharge voltage and internal resistance of alkaline and Li-FeS2 at a 50mA pulsed load. Of interest is the flat voltage curve and the low internal resistance of lithium; alkaline shows a rapid voltage drop and a permanent increase in resistance with use. This shortens the runtime, especially at an elevated load.
Figure 1 Voltage and internal resistance of Alkaline on Discharge
Figure 2 Voltage and internal resistance of Lithium on Discharge
Lithium-thionyl chloride (LiSOCI2 or LTC) is one of the most rugged lithium-metal batteries. The ability to withstand high heat and strong vibration enables horizontal drilling, also known as fracking. Some LTC are said to operate from 0°C to 200°C (32°F to 392°F). Other uses are in medical and sensor applications.
With a specific energy of over 500Wh/kg, LTC offers twice the capacity of the best Li-ion. The nominal voltage is 3.60V/cell; the end-of-discharge cut-off voltage is 3.00V. The runtime is not based on capacity alone; thermal conditions and load pattern also have an effect. Constant current is more enduring than pulsed load; a phenomenon that applies to most batteries.
Like alkaline, lithium-thionyl chloride has a relatively high resistance and can only be used for moderate discharge loads. If stored for a time, a passivation layer forms between the lithium anode and the carbon-based cathode that dissipates when applying a load. This layer protects the battery by granting low self-discharge and a long shelf life.
LTC is one of the most powerful and potent battery chemistries and should only be used by trained workers. For safety reasons, this battery is not used in consumer devices.
Lithium manganese dioxide (LiMnO2 or Li-M) is similar to LTC but has a lower specific capacity and is safe for public use. The voltage is 3.0–3.30V and the specific energy is about 280Wh/kg. Li-M is economically priced, has a long life and allows moderate loads but can deliver high pulse currents. Operational temperature ranges from -30°C to 60°C (-22°F to 140°F). Typical uses are meter sensing, medical devices, road toll sensors and cameras.
Lithium sulfur dioxide (LiSo2) is a primary battery with a voltage of 2.8V and an energy density up to 330Wh/kg. It offers a wide temperature range of --54°C to 71°C (-65°F to 160°F) with a projected shelf life of 5–10 years at room temperature. LiSo2 is inexpensive to make and is commonly used by the military. The Iraqi war used tons of these batteries, but it is giving way to the more superior Li-M.
Note: Primary lithium batteries are also known as lithium-metal. The cathode is carbon and the anode holds the active material, the reverse of Li-ion, which features a carbon anode.
Comparison Table of Secondary Batteries
Rechargeable batteries play an important role in our lives and many daily chores would be unthinkable without the ability to recharge. The most common rechargeable batteries are lead acid, NiCd, NiMH and Li-ion. Here is a brief summary of their characteristics.
Table 1 compares the characteristics of the four commonly used rechargeable battery systems, showing average performance ratings at time of publication. Li-ion is divided into different types, named by their active materials, which are cobalt, manganese, phosphate and titanate. )
Table 1 Characteristic of commonly used rechargeable batteries
Missing from in the list is the popular lithium-ion-polymer that gets its name from the unique separator and electrolyte system. Most are a hybrid version that shares performance with other Li-ion. Also missing is the rechargeable lithium-metal, a battery that, once the safety issues are resolved, has the potential of becoming a battery choice with extraordinarily high specific energy and good specific power. The table only addresses portable batteries and excludes large systems that resemble a refinery.
Battery cell types
Primary cells or non-rechargeable batteriesAlkaline battery
Secondary cells or rechargeable batteries
The Difference Between Primary and Secondary Battery
Primary and secondary batteries play crucial roles in energy storage, each offering distinct advantages and limitations. Understanding the disparity between these two types of batteries is essential for informed decision-making in various applications. This article delves into the disparities between primary and secondary batteries, elucidating their functionalities and implications for practical use.
Part 1. Primary battery
A primary battery, also known as a disposable battery, is designed for single use, and users cannot recharge it. These batteries generate electrical energy through a chemical reaction that occurs within them.?
It is commonly found in various everyday devices such as remote controls, flashlights, toys, and watches. Primary batteries come in different chemistries, including alkaline, zinc-carbon, and lithium. Each type has specific advantages and disadvantages, making them suitable for other applications. For example, alkaline batteries offer a long shelf life and high energy density. In contrast, zinc-carbon batteries are more affordable but have a shorter lifespan.
Part 2. Primary battery advantages and disadvantages
Advantages
Disadvantages?
Part 3. Secondary battery
A secondary battery, also known as a rechargeable battery, is a type of battery that users can recharge and reuse multiple times. Unlike primary batteries, designed for single use, secondary batteries utilize an external electrical current to reverse the chemical reaction during discharge, enabling users to renew them for multiple uses. This process restores the battery’s energy storage capacity, allowing the users to use it again. Secondary batteries power electronic devices such as smartphones, laptops, and electric vehicles, requiring frequent recharging to maintain functionality. They come in various chemistries, including lithium-ion, nickel-cadmium, and nickel-metal hydride, each with advantages and limitations.
Part 4. Secondary battery advantages and disadvantages
Advantages?
Disadvantages?
Part 5. What is the difference between a primary battery and a secondary battery?
Reusability
Chemical Reaction
Longevity
Cost
Environmental Impact
A Comprehensive Guide to Understanding Different Types of Lithium-Ion Batteries
Electric vehicles (EVs) are growing rapidly in popularity around the world as more environmentally conscious consumers seek alternatives to gasoline-powered cars. A major factor driving this EV revolution is innovations in lithium-ion battery technology that allow EVs to travel farther on a single charge. As you consider adding an EV to your driveway, it’s helpful to understand the different types of lithium-ion batteries and how they impact EV range and performance.
ESSENTIALS
Our absolute best battery friend these days is the lithium-ion battery. It’s the one that powers our mobile phones and laptops, devices that have made a massive contribution to changing the way we work and interact with our friends, colleagues, retailers and even strangers. The power demands made by our smart phones would flatten a NiCad or nickel-metal hydride battery in less than an hour, but with the efficiency of the lithium-ion chemistry, we can chat to our mum, watch videos, message our friends, listen to music, buy a pair of shoes online, be provided with navigational instructions and take countless photos all day long.
So what’s so special about lithium-ion batteries? Their main drawcard is their energy density—it’s around double that of a NiCad battery, meaning that a battery half the size will give the same amount of power. They’re light and compact which means they’re better for things like portable electronics than the heavy lead-acid batteries that start our petrol cars.
Lithium-ion battery chemistry
As the name suggests, lithium ions (Li+) are involved in the reactions driving the battery. Both electrodes in a lithium-ion cell are made of materials which can intercalate or ‘absorb’ lithium ions (a bit like the hydride ions in the NiMH batteries. Intercalation is when charged ions of an element can be ‘held’ inside the structure of a host material without significantly disturbing it. In the case of a lithium-ion battery, the lithium ions are ‘tied’ to an electron within the structure of the anode. When the battery discharges, the intercalated lithium ions are released from the anode, and then travel through the electrolyte solution to be absorbed (intercalated) in the cathode.
A lithium-ion battery starts its life in a state of full discharge: all its lithium ions are intercalated within the cathode and its chemistry does not yet have the ability to produce any electricity. Before you can use the battery, you need to charge it. As the battery is charged, an oxidation reaction occurs at the cathode, meaning that it loses some negatively charged electrons. To maintain the charge balance in the cathode, an equal number of some of the positively charged intercalated lithium ions are dissolved into the electrolyte solution. These travel over to the anode, where they are intercalated within the graphite. This intercalation reaction also deposits electrons into the graphite anode, to ‘tie’ up the lithium ion.
During discharge, the lithium ions are de-intercalated from the anode and travel back through the electrolyte to the cathode. This also releases the electrons that were tying them to the anode, and these flow through an external wire, providing the electric current that we used to do work. It’s the connection of the external wire that enables the reaction to proceed—when the electrons are free to travel, so are the positively charged lithium ions that will balance the movement of their negative charge.
When the cathode becomes full of lithium ions, the reaction stops and the battery is flat. Then we recharge our lithium-ion batteries again, and the external electric charge that we apply pushes the lithium ions back into the anode from the cathode.
The electrolyte in a lithium-ion cell is usually a solution of lithium salts in a mixture of solvents (like dimethyl carbonate or diethyl carbonate) devised to improve battery performance. Having lithium salts dissolved in the electrolyte means the solution contains lithium ions. This means that individual lithium ions don’t have to make the complete journey from the anode to the cathode to complete the circuit. As ions are kicked out from the anode, others that are already hanging out in the electrolyte, near the electrode surface, can easily be absorbed (intercalated) into the cathode. The reverse happens during recharging.
Microscopic materials used for Lithium-ion cathode
Being small and light, a lot of lithium can be stored (intercalated) in both the electrodes. This is what gives lithium-ion batteries their high energy density. For example, one lithium ion can be stored for every six carbon atoms in the graphite, and the more lithium ions there are to share the travelling from the anode to the cathode (and back again during recharge cycles), the more electrons there are to balance out their movement and provide the electric current.
The transfer of lithium ions between the electrodes occurs at a much higher voltage than in other battery types and, as they must be balanced by an equal amount of electrons, a single lithium-ion cell can produce a voltage of 3.6 volts or higher, depending on the cathode materials. A typical alkaline cell produces only around 1.5 volts. A standard lead-acid car battery needs six 2-volt cells stacked together to produce 12 volts.
Because of their high energy density, and their comparative lightness, stacking lots of lithium-ion cells together in the one place produces a battery pack far lighter and more compact than stacks made of other battery types. If we stack enough lithium-ion cells together, we can reach a pretty high voltage, such as that required to run an electric car. Sure, all our cars have batteries already, but they’re just to get a petrol or diesel engine going, then the fuel does all the work. An electric car’s battery is its entire energy source, and what gives it the grunt to get up a steep hill. So, it typically will have 96 volts or even more which, even with the high voltage of a lithium-ion cell, requires quite a few cells stacked together.
Stacking Lithium ion cells together can create enough voltage to run an electric car
The anode is usually graphite. However, the repeated insertion of lithium ions into the standard graphite structure in a typical lithium-ion battery eventually breaks apart the graphite. This reduces the battery’s performance and the graphite anode will eventually break down, and the battery will stop working. Researchers are working on developing options to use graphene(single-atom thick sheets of carbon) rather than graphite. You’ll get to read more about graphene and why it’s great in an upcoming Nova topic.
In terms of the material used for the cathode, there are quite a few variations—generally made of a combination of lithium, oxygen, and some kind of metal.
The cathodes used in lithium-ion batteries
LITHIUM COBALT OXIDE (LiCoO2)
The most common lithium-ion cells have an anode of carbon (C) and a cathode of lithium cobalt oxide (LiCoO2). In fact, the lithium cobalt oxide battery was the first lithium-ion battery to be developed from the pioneering work of R Yazami and J Goodenough, and sold by Sony in 1991. The cobalt and oxygen bond together to form layers of octahedral cobalt oxide structures, separated by sheets of lithium. It’s important that this structure allows the cobalt ions to change their valence states between Co+3 and Co+4 (lose and gain a negatively-charged electron) when charging and discharging.
Of all the various lithium-ion batteries, these guys have the greatest energy density, which is why they’re currently the batteries found in our phones, digital cameras and laptops. Their drawback is their thermal instability. Their anodes can overheat and, at high temperatures, the cobalt oxide cathode can decompose, producing oxygen. If you combine oxygen and heat, you’ve got a pretty good chance of starting a fire and, as the chemicals sometimes used in the electrolyte solution, such as diethyl carbonate, are flammable, there can be some safety issues with this battery.?
Lithium-ion batteries have in-built protections to prevent overheating, and to prevent the complete discharge of the battery which can also be damaging. Additionally, these protection circuits can sometimes be used to prevent over-charging of lithium-ion batteries, which can have serious consequences. Lithium-ion batteries come in a wide variety of shapes and sizes, and some contain in-built protection devices, such as venting caps, to improve safety.?
DURING DISCHARGE
At the anode, lithium is oxidised. Lithium?ions are released from the carbon, along with electrons:
LiC6→xLi++xe?+C6
At the cathode, lithium-ions are absorbed by the lithium dioxide, and the electrode is reduced as it also receives the electrons from the circuit:
Li1?xCoO2+xLi++xe?→LiCoO2
The overall reaction is:
C6+LiCoO2?LixC6+Li1?xCoO2
LITHIUM IRON PHOSPHATE (LiFePO4)
This cell has a high discharge rate and, because phosphate (PO4) can cope with high temperatures, the battery has good thermal stability, improving its safety. This makes it a good choice for things like electric vehicles and power tools, and for storing energy at power stations. It also has a long cycle life, meaning it can be discharged and charged many times. However, it has a lower energy density than a lithium cobalt oxide cell, and a higher self-discharge rate.
A lithium iron phosphate battery cell is similar to the lithium cobalt oxide cell. The anode is still graphite and the electrolyte is also much the same. The difference is that the lithium cobalt dioxide cathode has been replaced with the more stable lithium iron phosphate. In fact, no lithium or iron ions remain in the iron phosphate (FePO4) cathode of a fully charged cell. The lithium ions can intercalate into or out of the cathode material through well-defined tunnels in its structure without significantly altering the iron phosphate framework.?
The cathode of this type of cell is made of negatively charged phosphate anions, bonded with positively charged iron cations in a structure that is capable of storing lithium ions within the iron phosphate molecules. The bonding arrangement in this structure means that the oxygen atoms are tightly bonded into the structure, which gives the cathode its chemical stability.
DURING DISCHARGE
At the anode, lithium is oxidised. Lithium ions are released from the carbon, along with electrons:
LiC6→Li++e?+C6
At the cathode, lithium ions are absorbed by the lithium dioxide, and the electrode is reduced as it also receives the electrons from the circuit:
LiFe(III)PO4+xLi++xe?→LiFe(II)PO4
FePO4+Li++e?→LiFePO4
The overall reaction is:
LiFePO4+6C→LiC6+FePO4
LITHIUM MANGANESE OXIDE (LiMn2O4)
This type of lithium battery uses a cathode made from lithium-manganese spinel (Li+Mn3+Mn4+O4). Spinel is a type of mineral with a distinctive AB2O4 structure. The spinel structure has very good thermal stability, improving the battery’s safety. It also promotes ion flow within the electrolyte and lessens the internal resistance that contributes to the loss of a battery’s power over time.?
While this type of lithium battery offers high discharge and recharge rates (also due to the spinel structure of the cathode) it has a lower capacity and shorter lifetime.?
LITHIUM NICKEL MANGANESE COBALT OXIDE (LiNiMnCoO2 or NMC)
Adding nickel and cobalt back into the mix changes things slightly again. Nickel provides a high specific energy and, when added to the stable structure of the manganese spinel, also results in a battery with the benefits of the manganese spinel structure (low internal resistance, high charging rate, good stability and safety). ?
These batteries are generally made with a cathode with one-third nickel, one-third manganese and one-third cobalt, but the ratio can vary according to manufacturers’ secret formulas. These batteries are used in power tools, electric vehicles and medical devices.
Lithium manganese batteries are often coupled with a lithium nickel manganese cobalt oxide battery, producing a combination that is used in many electric vehicles. High bursts of energy (for rapid acceleration) are provided by the lithium-manganese component, and a long driving range is provided by the lithium nickel manganese cobalt oxide component.
LITHIUM POLYMER
Replacing the liquid electrolyte in a lithium-ion battery with a solid electrolyte improves the battery’s safety and makes it lighter. As the polymer itself is extremely thin, it also enables greater flexibility in terms of shape and design—it need not be contained in a rigid case, and can be made to be extremely compact.?
The polymer electrolyte is a non-conducting material that still allows ion exchange. In early designs the polymer was such a poor conductor that it was unable to facilitate ion exchange unless heated to around 60 degrees Celsius, so small amounts of gel are now added to avoid this issue.?
The lithium polymer battery can use any combination of electrodes found in lithium-ion batteries; it is simply the electrolyte that differs. ?
Just as batteries in general come in all shapes, sizes and chemistries, so do lithium-ion batteries. Their various different chemistries and structures offer different features, often with trade-offs between efficiency, cost and safety.?
Lithium-ion batteries are essential to the way we go about our everyday lives. They’ll be with us for some time to come, as they are currently the best bet for powering electric vehicles ?and storing energy generated from wind ?and solar sources to use at times when the wind isn’t blowing or the sun not shining.?
A researcher is working on fabrication and assembly of Lithium-ion battery cells.
What exactly is a Lithium-Ion Battery?
A lithium-ion or Li-ion battery is a type of rechargeable battery that uses the reversible intercalation of Li+ ions into electronically conducting solids to store energy. In comparison with other commercial rechargeable batteries, Li-ion batteries are characterized by higher specific energy , higher energy density , higher energy efficiency , a longer cycle life , and a longer calender life. Also noteworthy is a dramatic improvement in lithium-ion battery properties after their market introduction in 1991: within the next 30 years, their volumetric energy density increased threefold while their cost dropped tenfold.
There are at least 12 different chemistries of Li-ion batteries; see
The invention and commercialization of Li-ion batteries may have had one of the greatest impacts of all technologies in human history as recognized by the 2019 Noble prize in chemistry. More specifically, Li-ion batteries enabled portable consumer electronics, laptop computers, cellular phones, and electric cars., or what has been called the e-mobility revolution. It also sees significant use for grid scale energy storage as well as military and aerospace applications.
Lithium-ion cells can be manufactured to optimize energy or power density. Handheld electronics mostly use lithium polymer batteries (with a polymer gel as an electrolyte), a lithium cobalt oxide (LiCoO 2) cathode material, and a graphite anode, which together offer high energy density. Lithium iron phosphate (LiFePO 4), Lithium manganese oxide (LiMn 2O 4 spinel, or Li 2MnO 3-based lithium-rich layered materials, LMR-NMC), and Lithium nickel manganese cobalt oxide (LiNiMnCoO 2 or NMC) may offer longer life and a higher discharge rate. NMC and its derivatives are widely used in the electrificatin of transport , one of the main technologies (combined with renewable energy) for reducing greenhouse gas emissions from vehicles.
The first prototype of the modern Li-ion battery, which uses a carbonaceous anode rather than lithium metal, was developed by AKIRA YOSHINO in 1985 and commercialized by a SONY and ASAHI KASEI team led by Yoshio Nishi in 1991.
Lithium-ion batteries can be a safety hazard if not properly engineered and manufactured because they have flammable electrolytes that, if damaged or incorrectly charged, can lead to explosions and fires. Much progress has been made in the development and manufacturing of safe lithium-ion batteries. Lithium-ion solid state batteries are being developed to eliminate the flammable electrolyte. Improperly recycled batteries can create toxic waste, especially from toxic metals, and are at risk of fire. Moreover, both lithium and other key strategic minerals used in batteries have significant issues at extraction, with lithium being water intensive in often arid regions and other minerals used in some Li-ion chemistries potentially being conflict minerals such as cobalt . Both environmental issues have encouraged some researchers to improve mineral efficiency and find alternatives such as Lithium iron phosphate lithium-ion chemistries or non-lithium-based battery chemistries like iron air batteries..
Research areas for lithium-ion batteries include extending lifetime, increasing energy density, improving safety, reducing cost, and increasing charging speed, among others. Research has been under way in the area of non-flammable electrolytes as a pathway to increased safety based on the flammability and volatility of the organic solvents used in the typical electrolyte. Strategies include aqueous lithium-ion batteries, ceramic solid electrolytes, polymer electrolytes, ionic liquids, and heavily fluorinated systems.
A Lithium-ion battery is a rechargeable battery commonly used in consumer electronics and increasingly popular in electric vehicles. It uses lithium metal oxides for the positive electrode (cathode) and carbon materials for the negative electrode (anode). When the battery is charging, lithium ions flow from the cathode to the anode. When discharging, the lithium ions flow back to the cathode, generating an electric current that powers the components.
Compared to older rechargeable battery chemicals like nickel-cadmium and nickel-metal hydride, lithium-ion batteries offer:
How do lithium-ion batteries produce electricity?
There are various types of batteries besides lithium-ion batteries, but in fact, the basic mechanism by which they produce electricity is the same in all of them.
Batteries have a positive electrode (cathode) and a negative electrode (anode) made out of metal, between which they are filled with a substance (electrolyte) that conducts electricity carried by ions. The metal electrodes are dissolved by the electrolyte, dividing into ions and electrons. When the electrons move from the anode to the cathode, an electric flow (current) is generated, creating electricity. In secondary cells, electrons are stored at the anode by charging before starting to use the battery, and electricity is produced by the stored electrons moving to the cathode when using the battery.
Lithium-ion batteries use a metal compound into which lithium is embedded in advance as the cathode. Carbon, which can store that lithium, is used as the anode. This structure generates electricity without dissolving the electrodes in an electrolyte like conventional batteries. In addition to suppressing deterioration of the battery itself and allowing more electricity to be stored, this also enables the battery to be charged and discharged more times. Moreover, since lithium is a very small and light substance, it enables various advantages such as the creation of smaller and lighter batteries.
Understanding Key Performance Metrics
As you evaluate lithium-ion batteries, there are two key metrics to consider:
Energy Density: This refers to how much energy a battery can store per unit volume or weight. A higher energy density means the battery can be smaller and lighter while storing the same usable capacity.
Specific Energy: Also called gravimetric energy density, this is the measure of how much energy a battery can store per unit of weight. This metric directly impacts driving range – batteries with higher specific energy can power the vehicle farther.
In addition to optimizing these metrics, battery researchers also focus on safety, lifetime cycles, charging rates, low-temperature operation, and production costs. Improvements in all areas are critical for the continued adoption of electric vehicles.
Types of Lithium-Ion Batteries
LFP MAP
NCM MAP
Lithium Nickel Manganese Cobalt (LiNixMnyCozO2 or NMC)
Lithium Nickel Cobalt Aluminium Oxide (LiNiCoAlO2 or NCA)
Lithium Iron Phosphate (LiFePO4 or LFP)
Lithium Cobalt Oxide (LiCoO2 or LCO)
Lithium Manganese Oxide (LiMn2O4 or LMO)
Lithium Titanate (Li2TiO3 or LTO)
Each battery chemistry is judged across six metrics to determine which application it would be best suited for:
Not all lithium-ion batteries are created equal. There are actually many different lithium-ion chemistries, each with its pros and cons. We’ll give an overview of the most common types you’ll find in electric vehicle applications.
Lithium Nickel Manganese Cobalt Oxide (NMC)
Lithium nickel manganese cobalt oxides (abbreviated NMC, Li-NMC, LNMC, or NCM) are mixed metal oxides of lithium, nickel, manganese and cobalt with the general formula LiNixMnyCo1-x-yO2. These materials are commonly used in lithium-ion batteries for mobile devices and electric vehicles,, acting as the positively charged cathode.
A general schematic of a lithium-ion battery. Lithium ions intercalate into the cathode or anode during charging and discharging.
There is a particular interest in optimizing NMC for electric vehicle applications because of the material's high energy density and operating voltage. Reducing the cobalt content in NMC is also a current target, owing to ethical issues with cobalt mining and the metal's high cost. Furthermore, an increased nickel content provides more capacity within the stable operation window.
Lithium nickel manganese cobalt is one of the world’s leading chemistries, providing high specific energy while offering good safety and performance levels. It is also inexpensive to produce and has a decent lifespan of around 2,000 charge cycles, giving it an excellent cost-life ratio. Its nominal voltage is 3.6V, with an energy density of 150-220Wh/kg, making it ideal for various electric vehicles. NMC also has the lowest self-heating rate of the six configurations we’ll see in this piece, while its energy storage capacity at low weight and volume makes it an ideal option if space is tight. NMC’s chemical component quantities can be configured to include different amounts. For example, NMC111 comprises one-third each nickel, manganese and cobalt, whereas NMC 532 would be 50% nickel, 30% manganese and 20% cobalt. Other market-successful structures are NMC811 and NMC622, although with cobalt becoming more expensive and difficult to source sustainably, there’s a global push to use less cobalt in operations, or none at all where possible.
NMC cathodes typically contain large proportions of nickel, which increases the battery’s energy density and allows for longer ranges in EVs. However, high nickel content can make the battery unstable, which is why manganese and cobalt are used to improve thermal stability and safety.
NMC batteries use a cathode chemistry composed of nickel, manganese, and cobalt. They offer high energy density, moderate cost, and less susceptibility to overheating compared to other lithium-ion batteries. This makes them a popular choice for electric vehicles:
The percentage makeup of nickel, manganese, and cobalt can be adjusted to tweak performance metrics. For example, increasing nickel content raises energy density, while boosting manganese improves stability and safety.
Lithium Nickel Manganese Cobalt Oxide: LiNiMnCoO2. cathode, graphite anode Short form: NMC (NCM, CMN, CNM, MNC, MCN similar with different metal combinations) Since 2008
Voltages 3.60V, 3.70V nominal; typical operating range 3.0–4.2V/cell, or higher
Specific energy (capacity) 150–220Wh/kg
Charge (C-rate) 0.7–1C, charges to 4.20V, some go to 4.30V; 3h charge typical. Charge current above 1C shortens battery life. Charge must be turned off when current saturates at 0.05C.
Discharge (C-rate) 1C; 2C possible on some cells; 2.50V cut-offCycle life1000–2000 (related to depth of discharge, temperature)
Thermal runaway 210°C (410°F) typical. High charge promotes thermal runaway
Cost~ $420 per kWh[1]
Applications E-bikes, medical devices, EVs, industrial
Comments Update: NMC. Nickel manganese cobalt (NMC) batteries contain a cathode made of a combination of nickel, manganese, and cobalt. NMC is one of the most successful cathode combinations in Li-ion systems. It can be tailored to serve as energy cells or power cells like Li-manganese. NMC batteries are used for power tools, e-bikes, and other electric powertrains. Provides high capacity and high power. Serves as Hybrid Cell. Favorite chemistry for many uses; market share is increasing. Leading system; dominant cathode chemistry.
Lithium Iron Phosphate (LFP)
领英推荐
Low specific energy is the only real drawback of the lithium iron phosphate battery chemistry, as it offers good metrics in everything else. A lifespan of around 10,000 charge cycles depending on state of charge and depth of discharge, high specific power and naturally stable make LFP a favourite for applications that don’t require high speeds. Furthermore, LFP batteries have a flat discharge curve, which means that as the battery depletes, performance does not suffer, unlike other li-ion battery configurations. The LFP battery is known to be long-lasting, making it ideal for labour-intensive operations. This makes it one of the most cost-effective options on the market, with the absence of cobalt also lowering the production price. It’s widely used in various markets, including airport ground support, marine, robotics, agriculture, mining and construction.
Due to their use of iron and phosphate instead of nickel and cobalt, LFP batteries are cheaper to make than nickel-based variants. However, they offer lesser specific energy and are more suitable for standard- or short-range EVs. Additionally, LFP is considered one of the safest chemistries and has a long lifespan, enabling its use in energy storage systems.
LFP batteries use a cathode chemistry based on iron phosphate. They have a lower energy density than NMC but offer other advantages:
Lithium Iron Phosphate: LiFePO4 cathode, graphite anode Short form: LFP or Li-phosphate
Voltages 3.20, 3.30V nominal; typical operating range 2.5–3.65V/cell
Specific energy (capacity) 90–120Wh/kg
Charge (C-rate) 1C typical, charges to 3.65V; 3h charge time typical Charge must be turned off when current saturates at 0.05C.
Discharge (C-rate) 1C, 25C on some cells; 40A pulse (2s); 2.50V cut-off (lower that 2V causes damage)
Cycle life 2000 and higher (related to depth of discharge, temperature)
Thermal runaway 270°C (518°F) Very safe battery even if fully chargedCost~$580 per kWh
Applications Portable and stationary needing high load currents and endurance
Comments 2019 Update: Very flat voltage discharge curve but low capacity. One of safest Li-ions. Used for special markets. Elevated self-discharge. Used primarily for energy storage, moderate growth.
The tradeoff is less driving range compared to NMC for a similarly sized battery pack. However, new advancements in LFP energy density continue to close this gap.
Lithium Titanate Oxide (LTO)
Lithium titanate is also renowned for its safety and has a longer lifespan than LFP, clocking in some 15,000 charge cycles. LTO has fast charging capabilities and good specific power and performance across a vast temperature range, making it ideal for the OHEV market. Its two major drawbacks, however, are the cost it takes to produce LTO batteries and the low specific power. It has found use in aerospace and military equipment, as well as vehicle powertrains and solar-powered applications, and having entered the market in 2008, there’s still scope to develop this battery chemistry further.
Unlike the other chemistries above, where the cathode composition makes the difference, LTO batteries use a unique anode surface made of lithium and titanium oxides. These batteries exhibit excellent safety and performance under extreme temperatures but have low capacity and are relatively expensive, limiting their use at scale.
LTO batteries substitute titanium oxide for the traditional graphite anode. They charge extremely rapidly and have a high cycle count, making them most suitable for hybrid EVs.
The high cost and lower energy density make LTO less ideal for pure battery electric vehicles needing extended range.
Lithium Cobalt Oxide (LCO)
Lithium cobalt oxide creates a battery chemistry high in specific energy, with a nominal voltage of 3.7V and an energy density of 150 to 180Wh/kg. This high specific energy but low specific power means low power loads can be delivered over an extended period, hence LCO batteries are usually found in smartphones, tablets, and laptops. However, it’s a chemistry that scores low in safety, especially thermal stability, as high intensity will cause the battery to overheat, increasing thermal runaway risk. Portable devices now have increased computing power, so higher specific power rates must be delivered safely. So, combined with a lifespan of fewer than 1,000 charge cycles, the LCO chemistry’s days appear somewhat numbered as various industries invest in other cheaper, more efficient battery technologies.
Although LCO batteries are highly energy-dense, their drawbacks include a relatively short lifespan, low thermal stability, and limited specific power. Therefore, these batteries are a popular choice for low-load applications like smartphones and laptops, where they can deliver relatively smaller amounts of power for long durations.
Lithium-cobalt oxide batteries offer high specific energy but low stability. This makes them suitable for compact consumer electronics like mobile phones and tablets, which require optimum energy density. The cathode in an LCO battery contains cobalt oxide material.
Key features:
– High specific energy density
– Low thermal stability
Medium-specific power
– Average cycle life
– Used in mobile phones, tablets, and cameras
COMMENT : LiCoO2 is the most commonly used cathode material. LiCoO2 batteries have very stable capacities, although their capacities are lower than those based on nickel-cobalt-aluminum (NCA) oxides. However, cobalt is relatively expensive compared to other transition metals, such as manganese and iron, despite the attractive electrical properties of LiCoO2 cathodes. Currently, we can find this type of battery in mobile phones, tablets, laptops, and cameras.
Lithium Manganese Oxide (LMO)?
While lithium manganese oxide scores high across most metrics, its low lifespan of around 700 charge cycles is undoubtedly a drawback. Its high nominal voltage of 3.9V, an energy density of 100-150Wh/kg, thermal stability and low self-discharge rate make it a safe option for power-intense applications. It’s cheap to produce, and manganese oxide is a non-toxic, earth-abundant metal, unlike cobalt. LMO’s internal chemistry can be configured to suit high-load use or long-range driving as required and is also being developed to extend its charge cycle total. LMO has also been paired with the NMC chemistry for high current upon acceleration and long driving range in the mobility sphere.
Also known as manganese spinel batteries, LMO batteries offer enhanced safety and fast charging and discharging capabilities. In EVs, LMO cathode material is often blended with NMC, where the LMO part provides a high current upon acceleration, and NMC enables longer driving ranges.
Lithium manganese oxide, or LMO, batteries offer improved thermal stability over LCO batteries. They also have a higher operating voltage. But they come with less specific energy. LMO batteries find use in both consumer gadgets as well as electric powertrains.
Key features:
– Better thermal stability than LCO
– Higher operating voltage
– Lower energy density than LCO
– Often used with LCO cathodes in blends
– Used in power tools, medical devices, and electric bicycles
COMMENT : LiMn2O4 is a promising cathode material with a cubic spinel structure. LiMn2O4 is one of the most studied manganese oxide-based cathodes because it contains inexpensive materials. A further advantage of this battery is enhanced safety and high thermal stability, but the cycle and calendar life is limited. This type of battery is found in power tools, medical devices, and powertrains.
Lithium Nickel Cobalt Aluminum Oxide (NCA)
In 1999, Lithium nickel cobalt aluminum oxide battery, or NCA, appeared in some special applications, and it is similar to the NMC. It offers high specific energy, a long life span, and a reasonably good specific power. NCA’s usable charge storage capacity is about 180 to 200 mAh/g. The capacity of NCA is significantly higher than that of alternative materials such as LiCoO2 with 148 mAh/g, LiFePO4 with 165 mAh/g, and NMC 333 (LiNi0,33Mn0,33Co0,33O2)with 170 mAh/g. The voltage of these batteries is between 3.6 V and 4.0 V, at a nominal voltage of 3.6 V or 3.7 V. Another advantage of NCA is its excellent fast charging capability. Nevertheless, its weak points are the limited resources of cobalt and nickel and the high cost
A 200-260Wh/kg energy density and a nominal voltage of 3.6V makes this combination ideal for EV powertrains, although there are safety concerns that need to be managed for this chemistry and high costs to keep in mind. NCA-configured batteries can be found in high-performance EVs or duty-intensive off-highway electric vehicles (OHEVs) alike since they can sustain high charge rates for fast charging and deliver relatively high current for extended periods. They also have a high cycle life of over 2,000 charge cycles. The higher nickel quantity provides the high specific energy and makes the cells less stable. Therefore, more safety measures are required to prevent battery damage and keep users safe.
NCA batteries share nickel-based advantages with NMC, including high energy density and specific power. Instead of manganese, NCA uses aluminum to increase stability. However, NCA cathodes are relatively less safe than other Li-ion technologies, more expensive and typically only used in high-performance EV models.
NCA cathode chemistry contains a mix of nickel, cobalt, and aluminum. They are related to NMC batteries but use aluminum instead of manganese. NCA batteries offer very high capacity and good energy density, comparable to LCO. But stability is inferior to NMC, and cycle life is also lower.
Key features:
– Very high capacity
– Good energy density
– Lower stability than NMC batteries
– Used in electric vehicles and laptops
COMMENT : NCA. In 1999, Lithium nickel cobalt aluminum oxide battery, or NCA, appeared in some special applications, and it is similar to the NMC. It offers high specific energy, a long life span, and a reasonably good specific power. NCA’s usable charge storage capacity is about 180 to 200 mAh/g. The capacity of NCA is significantly higher than that of alternative materials such as LiCoO2 with 148 mAh/g, LiFePO4 with 165 mAh/g, and NMC 333 (LiNi0,33Mn0,33Co0,33O2)with 170 mAh/g. The voltage of these batteries is between 3.6 V and 4.0 V, at a nominal voltage of 3.6 V or 3.7 V. Another advantage of NCA is its excellent fast charging capability. Nevertheless, its weak points are the limited resources of cobalt and nickel and the high cost.
Batteries of the future
ESSENTIALS
Batteries have been around for hundreds of years, and they’re going to be with us for some time to come. The many and varied applications for batteries has meant numerous permutations of the electrochemical cell over the years—different metals and other materials have been used for electrodes, different substances have been used for electrolytes, and there have been different ways of putting it all together. But what does the future hold?
New battery chemistries
Variations upon a theme: new lithium-ion technologies
SILICON ANODE
Silicon (Si) offers a huge increase in energy storage capability when used as an anode material. When compared to the traditional graphite electrode, silicon offers a theoretical tenfold increase in capacity. However, while its lattice structure can incorporate the lithium ions needed to drive a lithium-ion battery, the inclusion of lithium ions causes a significant increase in volume—more than 300 per cent. When the battery discharges, and the lithium ions are released from the silicon anode, the silicon shrinks. Over time, this repeated expansion and shrinking fractures and cracks the silicon anode and the battery has a very short lifespan.
Solving this major problem promises to produce a battery with a significantly better energy density than a standard lithium-ion battery with a graphite anode. One option being researched is coating the silicon with graphene?(single-atom-thick sheets of carbon), as the graphene sheets can ‘slide’ against each other, and compensate for the expansion and contraction of the silicon. This nearly doubles the battery’s energy density.
Amorphous silicon balls that are being used to investigate the changes silicon undergoes when used as an anode in a lithium-ion battery
GRAPHENE ANODE
Graphene could also replace graphite as a lithium-ion battery’s anode. Graphene is made of carbon atoms joined together to form a single-atom-thick sheet. While graphite is essentially formed of multiple graphene sheets stacked on top of each other, the benefits of being able to stack individual sheets of graphene allows for easier and more efficient intercalation?of lithium ions.
Attempting to insert lithium ions rapidly into the graphite, which is necessary for high power or fast charging applications, also causes the anode to break down. Graphene sheets could be used for high power applications, since the lithium ions do not need to tunnel through the graphite crystal to get to their insertion sites, as the sites are already open to the lithium-ion containing electrolyte. This new material has a lot of scientists worldwide trying to develop it into a new battery electrode material.
Graphine is made from single sheets of carbon atoms bonded together in a honeycomb like structure
LITHIUM-AIR
What if a battery could pull its power out of thin air? A lithium-air battery would do just that, by using oxygen from the ambient atmosphere as its cathode material. This would obviously make the battery extremely light, giving it an energy density up to 10 times better than standard lithium-ion batteries—an energy density that could compete with petrol.
However, the lithium-air chemistry poses a few challenges. One is that, in its pure metal form, lithium is extremely reactive, and it is difficult to keep an anode made of lithium stable. Finding electrolyte materials that can keep the anode stable, along with preventing it from reacting with oxygen from the air, is a challenge.
There is a lot of research on electrolytes looking to solve this problem, including using polymers, ionic liquids and high salt concentration solvent mixtures. Preventing reaction with air can also be achieved by coating the electrode with a solid electrolyte like glass or ceramic. The other problem is that the reduction of oxygen results in the formation of lithium peroxide (Li2O2). This can then coat the surface of the electrodes and supresses the reaction by which lithium ions and electrons are released, quashing the battery’s power. As the cell is exposed to air from which it draws the oxygen for the cathode reaction, it’s also exposed to water vapour and carbon dioxide, which can affect the chemistry of the cell by leading to the formation of other non-conductive and inactive materials such as Li2CO3.
In recent developments,?researchers at the University of Cambridge used a highly porous graphene as the cathode and added lithium iodide (LiI) and water (H2O) to the electrolyte mix. This prevented the formation of lithium peroxide, instead taking some hydrogen from the water to make lithium hydroxide (LiOH). The iodide acts as a ‘mediator’ that facilitates this reaction. The lithium hydroxide crystals fit nicely into the pores of the graphene cathode, but they do not coat its entire surface, leaving the carbon that is necessary to drive the battery’s electricity-generating reaction exposed and available to keep reacting.
When the battery is recharged, the iodide again steps in. It is oxidised to the triiodide ion (I3-). The triiodide reacts with the lithium hydroxide crystals, producing lithium ions (Li+), oxygen (O2) and water (H2O). This completely clears out the lithium hydroxide crystals from the cathode, leaving it accessible for the oxygen reduction reaction that occurs during battery discharge. ?Meanwhile, the lithium ions travel through the electrolyte and are redeposited on the anode as lithium metal, ready to again give up their electrons when the battery discharges.
UPON DISCHARGE
Electrochemical reaction:
4Li++4O2+4e?→4LiO2
Chemical reaction:
4LiO2+2H2O→(with LiI acting as mediator)4LiOH+3O2
UPON RECHARGE
Electrochemical reaction:
6I?→2I3?+4e?
Chemical reaction:
4LiOH+2I3?→4Li++6I?+2H2O+O2↑
(the up arrow indicates that the oxygen is released as a gas)
The lithium-air technology is still a fair way from practical commercialisation. Estimates are that it’ll take around 10–20 years for it to come to fruition. The developments described above work in a system that uses pure oxygen, so researchers also need to find a way to deal with the other stuff that air contains. Gases such as carbon dioxide and nitrogen in the air react with the lithium metal in the anode to form lithium carbonates and lithium nitrates which coat the electrode surface and prevent it from working effectively.
Scientist working on the development of lithium-ion and lithium air batteries
Lithium-sulphur is another promising battery chemistry for the future. ?
ALUMINIUM-AIR
As aluminium is a very common element found in Earth’s crust, a battery made from an aluminium anode and oxygen cathode promises to be very cheap. It will also be light, with a high energy density. An aluminium-air battery could potentially power an electric vehicle eight times further than the standard lithium-ion battery on a single charge.
The problem is that the chemistry that drives this battery cell results in the corrosion of the aluminium anode. As it reacts with the electrolyte, the aluminium anode undergoes an irreversible reaction to form hydrated aluminium oxide (Al(OH)3). This means the battery is not rechargeable, so either the anodes or the entire spent batteries would have to be replaced at regular intervals. The degraded anodes can be recycled to make fresh aluminium anodes.
The battery uses a water-based electrolyte, sometimes a salt solution, or a higher voltage can be obtained using potassium hydroxide (KOH).?
Aluminium-air battery chemistry could potentially be improved by the development of more porous, three-dimensional structures for the aluminium anode, which would increase the surface area of aluminium that’s available to react. Another possibility is the development of aluminium alloys, where adding in just tiny amounts of other elements would help prevent the formation of the aluminium hydroxide that corrodes the anode.
Because of the difficulties in recharging aluminium-air batteries, it’s unlikely that they’ll become a real commercial prospect in the near future, however ongoing research may yet get us there in the long run. Several groups around the world are looking at alternatives, however, such as magnesium-air and zinc-air batteries. Zinc-air batteries currently power our hearing aids and cochlear ear implants, however, reversibility?is a problem.
SODIUM-ION
Sodium-ion batteries work in a similar way to lithium-ion batteries, but with sodium ions instead of lithium. Advantages of sodium are that it is easy to source (just think sea water) and cheap.
While sodium ions are unlikely to compete with lithium-ion batteries to power portable devices or cars any time soon, some companies—Aquion Energy, Faradion, and Sharp Laboratories—are already producing them for use as energy storage at wind and solar farms. Smaller modules are also now being made for residential energy storage.
Sodium is cheap and easy to source Here crystals of common salt which is made of sodium chloride
There are a few different materials that have been used for electrodes in sodium-ion batteries. Carbon is commonly used for the anode, but not in a neat arrangement of graphite as in a lithium-ion battery. When incorporated into a uniform structure, the large sodium ions get stuck and can’t get out again, making the cell reaction irreversible (and the battery unrechargeable). What’s needed to prevent this is the right pore size and distribution, and a high surface area—so ‘hard carbon’, generally made by burning sugars at high temperature, is used as the anode. The temperature is critical to getting the right properties.
A possible option is an anode made from layers of graphene intersersed with layers of phosphorene. The graphene provides elasticity and electrical conductivity to the electrode, and the phosphorene changes the structure of the electrode such that sodium can move in and out easily during recharge and discharge.
A number of different materials have been tried out as cathodes for sodium-ion batteries, but research is ongoing to find the best candidate. Recently, researchers found that a compound of sodium, iron and sulphate provided an excellent host for sodium ions. The material is formed of layers of sodium and iron interspersed with sulphate structures, which provides good spaces in which to house the sodium ions. Prussian blue is another compound favoured for cathodes..
Entering the realm of sci-fi?
Piezoelectric
Piezoelectric materials can produce an electric charge when subjected to mechanical stress. Basically, if you squeeze, squish or press on it, that mechanical energy is converted into electrical energy.
STEP-POWERED
Researchers have developed a small device made from a coin-sized lithium-ion battery with its separator taken out and replaced with a piezoelectric film. It can be embededded into the sole of a shoe,, like your running sneaker. As you run, each time your foot hits the ground a small amount of force presses on the device, compressing the piezoelectric film in the middle. It generates a charge that causes the lithium ions to travel from the cathode to the anode—just like the recharging process that occurs when a normal lithium-ion battery is plugged into an external electricity source to recharge. The lithium ions that are pushed over to the anode react with the titanium oxide anode material to form lithium titanium oxide (LiTiO2), and are only released again when electricity is required to power a device. At this stage, it wouldn’t provide enough power to run your phone, but perhaps enough for things like GPS tracking devices. The key to this technology is developing the piezoelectric charge generation so that it can be connected to other battery types as well.
Essentially, this process involves mechanical energy being converted to chemical energy to charge the battery, then the normal chemical-to-electrical conversion when the battery is connected to an external circuit.
Step powered batteries could be placed inside your shoe or made part of the pavement we walked on.
SOUND-POWERED
Zinc oxide is a pieozoelectric material. When tiny nano-rods of it are exposed to soundwaves, they bend, creating physical stress that produces an electric current. The nano-rods are placed between metal sheets that act as the electrical contacts, drawing off the current created by the bending nano-rods. These electrical contacts can be made from common old aluminium foil.
The first attempt at building a sound-powered battery produced a device that can generate 5 volts—just by feeding off everyday noise like traffic, talking or music.
These plates of zinc oxide are grown to help researchers to understand the properties of zincoxide and how it will help in developing new type of batteries.
FIDGETING/FRICTION-POWERED
Another option in the future might be to harness the energy produced as people go about their daily business. Researchers are working on nano-generators—devices that can harness the static electricity generated from the friction produced by two substances rubbing together.
The device would contain a sheet of metal placed alongside a sheet of terephthalate plastic, both with nano-scale structures on their surfaces. When they come into contact, an electric charge is generated, and then the current flows when the sheets bend or flex. The nano-structures on the sheets’ surfaces increase the area available for contact.
This would be made into a small patch, possibly worn as an armband. It would soak up the energy produced as we walk around the house, pick up a book or type an email.
URINE-POWERED
A pee-powered battery sounds ridiculous!?Apparently not.
This technology is based on microbial fuel cells, which exploit the chemistry of the cell respiration process to produce electricity. After all, the chemistry underlying cell respiration is another set of redox reactions, just like those required to drive an electrochemical cell.
These particular microbial fuel cells contain live microbes that eat urine and break it down. Part of this process involves the production of electrons, which are, of course, what you need to generate an electric current. The idea is to take urine and feed it into pee-eating, microbe-containing cells, and harness the electrons produced to power electronic devices.
By placing several microbial fuel cells together in a series, researchers at the Bristol Robotics Lab?have produced a device that is capable of powering a mobile phone , and hope to scale it up to a size that would be capable of providing around 12 kilowatt hours power a day.
Microbial fuel cells process waste water and generate on electric current
What will these batteries do for us?
Developments in technology, particularly electronics, have changed the way we live our lives. What changes are in store for our children?and future generations?
RENEWABLE POWER
Adequate storage of the energy produced by renewable sources such as solar and wind ?is seen as the ‘missing link’ that’s required to power a future without dependence on fossil fuels.?
And we’re getting there. Redox flow batteries?are already being used on mine sites and in remote and rural areas to store solar-produced electricity. Their bulkiness is offset by the fact that they’re cheap and reliable. Trials in Australia have shown that these batteries can be used for residential applications, such as in the smart city grids scheme, where 30,000 homes were connected to renewable energy coupled with flow batteries.
As large lithium-ion batteries become more affordable, predictions are that more and more households will be equipped with a domestic battery, something in the scale of around 6–10 kWh capacity. These batteries could take in electricity from the grid during off-peak times when the cost is cheaper, and store it for use at peak times, thus reducing home owners’ power bills.
The other option is that, for houses with solar panels installed, the batteries would store any electricity that was generated during the day, but not used immediately, for use at night-time. Combined with smart management software, a household using a battery could also feed its stored electricity into the grid at peak demand times—and be paid for it.
Domestic batteries promise to be game changers, not only for the way households use and produce electricity, but for how the national electricity grid will function in the future. We’re not quite there yet, though. Although the Tesla Powerwall battery has arrived on the scene with a huge amount of hype and fanfare, it’s certainly not the first domestic battery to be invented—various types have been around for years. The problem is that they’ve simply been too expensive for broad uptake.
The promise of the Tesla Powerwall, and the associated Tesla Gigafactory,?is that it will bring costs down, which certainly ups the ante. Combined with predicted increases in grid electricity prices, we’ll almost certainly see a more widespread adoption of battery technology in our homes.
Another contender might be Oxis Energy in the United Kingdom. They’re currently testing lithium-sulphur batteries that store energy from a domestic-sized solar panel system, and hope to have them available for sale soon. Lithium-sulphur batteries are less expensive than lithium-ion batteries because sulphur is cheap and abundant. And, here in Australia, Redflow intends to soon be offering their zinc-bromide redox flow batteries as options for domestic storage as well.
WEARABLE BATTERIES
Small, light and flexible, and capable of drawing power from the mechanical energy of people carrying it around? That’s the promise of wearable battery devices.
One created by CSIRO uses walking to generate electricity. A generator placed into a backpack or garments converts the mechanical energy it experiences during walking or running into electricity. This electricity is then used to charge up a fabric-based flexible battery. Using conductive fabrics to make connections between all the different components makes it possible to design ‘flexible’ new wearable technologies.
While the CSIRO technology has been demonstrated in a backpack configuration,?the fabric used can be cut and shaped to any design simply by chopping it up with a pair of scissors—so the variety of possible garments or accessories is extensive.
Conclusion
Who would have thought that twitchy frog legs observed over 200 years ago?would ultimately lead to devices that can power our computers, smart phones, cars and, hopefully soon, our homes? Batteries have come a long, long way over the past few hundred years and, with so many scientists around the world investigating new technologies, it’s likely they’ll take us a long, long way into the future.
BATTERY CHEMISTRY DEFINITIONS AND GLOSSARY
Battery Chemistry Definitions & Glossary has quite a lot of overlap with the Cell Glossary. Hence apologies for any repeats, although some are required.
Ah?– Ampere-hour is the unit of cell capacity.
Anode – the negative or reducing electrode that releases?electrons?to the external circuit and oxidizes during and electrochemical reaction.
Anode-Cathode – in chemistry, we define Cathode as the electrode where reduction takes place and Anode the electrode where oxidation occurs. Both, during the discharge and recharge electrons move from the Anode to the Cathode. {Anode and Cathode swap places}.
Anode Free?– a battery cell where the Anode is formed during the cell formation cycles.
Binder – something that holds the active materials together.
Button Cell
Calender Ageing – the capacity loss of the battery with time and without cycling.
Calendaring –
Capacity?– battery capacity is expressed in ampere-hours.
Cathode – the positive electrode, at which electrochemical reduction takes place. As current flows, electrons from the circuit and cations from the electrolytic solution in the device move towards the cathode.
Charge – the process of electrical energy being converted into chemical energy.
Coating – the process of applying the active materials to the backing electrodes.
Coin Cell –
Coulomb – unit of electric charge. One?coulomb?(1C) equals one ampere-second (1As).
C rate – the Ampere current in charge or discharge divided by the Ah capacity of the cell.
Cycle Ageing – the capacity loss in a battery through charge and discharge repeated cycling.
Cycle Life – the number of charge and discharge cycles that a battery can complete before losing performance.
Discharge – the process of chemical energy being converted into electrical energy.
Dry Room –
Dry Separator – the separator is produced without solvents being used in the process.
EL Cell
Electrode
Electrolyte – the medium that allows ionic transport between the electrodes during charging and discharging of a cell.
Electrolyte Additives – used for a number of functions, including:
Formation –
Graphite
Humidity –
Instrumenting Cells – if you are going to instrument a cell you need to be able to do this reliably and robustly. The process flow diagram illustrates the experimental stages employed for cell instrumentation and includes: sensor fabrication, cell modification and sensor insertion. The diagram highlights the different verification stages for assessing LIB performance, operation and ageing.
Knee Point – describes a sudden change in the gradient of a cell cycling curve.
LCA – Life Cycle Analysis
LFP – Lithium Iron Phosphate, a?LITHIUM-ION?cathode material with graphite used as the anode. This cell chemistry is typically lower energy density than?NMC?or NCA, but is also seen as being safer.
LiPF6 – Lithium hexafluorophosphate
Lithium Plating – This is the deposition of metallic lithium on the surface of the graphite anode. This is one of the most significant degradation mechanisms.
LMB – Lithium Metal Battery
LMFP – Lithium manganese iron phosphate.
LMO – Lithium Manganese Oxide
LNMO – Lithium Nickel Manganese Oxide
LTMO – Layered Transition Metal Oxide
M3P – CATL's trade name for their own developed variation on LFP.
Na Ion – Sodium Ion battery cell.
Negative Electrode – the anode
NMC – Lithium Nickel Manganese Cobalt Oxides are a family of mixed metal oxides of?lithium,?nickel,?manganese?and?cobalt. Nickel is known for its high specific energy, but poor stability. Manganese has low specific energy but offers the ability to form spinel structures that allow low internal resistan
PbA – abbreviation of Lead acid battery
PBA – Prussian Blue Analogues
Positive Electrode – the cathode.
Primary Cell – a cell that can only be discharged once.
Secondary Cell – a rechargeable battery cell.
Self Discharge
Separator – material that separates the anode and cathode electrically whilst allowing ions to pass through.
Solid Electrolyte Interphase – is formed on electrode surfaces from decomposition products of electrolytes. The SEI allows Li+?transport and blocks electrons in order to prevent further electrolyte decomposition and ensure continued electrochemical reactions.
Solid State – anode, cathode and electrolyte are solid.
Third Electrode – electrode used in cells to establish the potential of the anode and cathode independently.
Wet Separator – the separator is produced using solvents.eplaced.SOLBAT
An all-solid-state battery would revolutionise the electric vehicles of the future. The successful implementation of an alkali metal negative electrode and the replacement of the flammable organic liquid electrolytes, currently used in Li-ion batteries, with a solid would increase the range of the battery and address the safety concerns. Current efforts to commercialise such batteries worldwide are failing and will continue to fail until we understand the fundamental processes taking place in these devices
Ranked: The Top 10 EV Battery Manufacturers in 2023
The Top 10 EV Battery Manufacturers in 2023
Despite efforts from the U.S. and EU to secure local domestic supply, all major EV battery manufacturers remain based in Asia.
In this graphic we rank the top 10 EV battery manufacturers by total battery deployment (measured in megawatt-hours) in 2023. The data is from EV Volumes.
Chinese Dominance
Contemporary Amperex Technology Co. Limited (CATL) has swiftly risen in less than a decade to claim the title of the largest global battery group.
The Chinese company now has a 34% share of the market and supplies batteries to a range of made-in-China vehicles, including the Tesla Model Y, SAIC’s MG4/Mulan, and Li Auto models.
COMPANY COUNTRY SHARE OF TOTAL PRODUCTION
CATL CHINA 34%
BYD CHINA 16%
LG ENERGY SOLUTION KOREA 15%
PANASONIC JAPAN 8%
SK ON KOREA 6%
SAMSUNG SDI KOREA 5%
CALB CHINA 3%
FARASIS ENERGY CHINA 2%
ENVISION AESC CHINA 1%
SUNWODA CHINA 1%
OTHERS 8%
In 2023, BYD surpassed LG Energy Solution to claim second place. This was driven by demand from its own models and growth in third-party deals, including providing batteries for the made-in-Germany Tesla Model Y, Toyota bZ3, Changan UNI-V, Venucia V-Online, as well as several Haval and FAW models.
The top three battery makers (CATL, BYD, LG) collectively account for two-thirds (66%) of total battery deployment.
Once a leader in the EV battery business, Panasonic now holds the fourth position with an 8% market share, down from 9% last year. With its main client, Tesla, now effectively sourcing batteries from multiple suppliers, the Japanese battery maker seems to be losing its competitive edge in the industry.
Overall, the global EV battery market size is projected to grow from $49 billion in 2022 to $98 billion by 2029, according to Frtune Business Insights.
Ranked: The World’s Largest Lithium Producers in 2023
The World’s Largest Lithium Producers in 2023
Three countries—Australia, Chile, and China—accounted for 88% of lithium production in 2023.
In this graphic, we list the world’s leading countries in terms of lithium production. These figures come from the latest USGS publication on lithium statistics (published Jan 2024).
Australia Leads, China Approaches Chile
Australia, the world’s leading producer, extracts lithium directly from hard-rock mines, specifically the mineral spodumene.
The country saw a big jump in output over the last decade. In 2013, Australia produced 13,000 metric tons of lithium, compared to 86,000 metric tons in 2023.
COUNTRY LITHIUM PRODUCTION 2023 METRIC TON
AUSTRALIA 86000
CHILE 44000
CHINA 33000
ARGENTINA 9600
BRAZIL 4900
CANADA 3400
ZIMBABAVE 3400
PORTUGAL 380
WORLDS 184680
Chile is second in rank but with more modest growth. Chilean production rose from 13,500 metric tons in 2013 to 44,000 metric tons in 2023. Contrary to Australia, the South American country extracts lithium from brine.
China, which also produces lithium from brine, has been approaching Chile over the years. The country increased its domestic production from 4,000 metric tons in 2013 to 33,000 last year.
Chinese companies have also increased their ownership shares in lithium producers around the globe; three Chinese companies are also among the top lithium mining companies . The biggest, Tianqi Lithium, has a significant stake in Greenbushes, the world’s biggest hard-rock lithium mine in Australia.
Argentina, the fourth country on our list, more than tripled its production over the last decade and has received investments from other countries to increase its output.
With all the top producers increasing output to cover the demand from the clean energy industry, especially for electric vehicle (EV) batteries, the lithium market has seen a surplus recently, which caused prices to collapse by more than 80% from a late-2022 record high.
Product manager at REC Sourcing Limited
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