Solid-state batteries with a range of 1,000 kilometers are coming, but we can’t afford them.

With the cold wind blowing, the owners of pure electric vehicles looked gloomy as they traveled thousands of kilometers home. A car with a nominal range of 600 kilometers has only been driven for more than 200 kilometers, and the battery is already less than 20% charged. After entering the service area, I couldn't find a parking space or a charging pile.

Every winter, pure electric vehicle owners experience battery life anxiety. Only larger-capacity batteries are commercially available to increase the battery life of pure electric vehicles to thousands of kilometers. Even if it shrinks in winter to only 500 or 600 kilometers, I am afraid that the user's battery life can be completely solved.

Researchers at Harvard University's John A. Paulson School of Engineering and Applied Sciences (SEAS) recently announced another type of lithium metal solid-state battery that may solve the battery life problem of pure electric vehicles.

Solid-state batteries, hope to solve battery life anxiety

Battery life anxiety exists because the energy density of the lithium batteries currently installed in electric vehicles is too low. The energy density of ternary lithium batteries or lithium iron phosphate batteries, which are more prevalent in domestic automobiles, usually does not exceed 250Wh/kg.

The energy consumption of ordinary B-class cars and SUVs per 100 kilometers is around 15kWh. If you want to achieve a driving range of 1,000 kilometers, you will need a battery of about 150KWh, which weighs about 600kg. However, a large battery takes up too much space, and its weight will also affect battery life. Therefore, research and development on high-energy-density batteries have never stopped, and currently, the most likely solution is solid-state batteries.

The core difference between solid-state and traditional batteries is that solid electrolytes replace electrolytes, and lithium metal anodes replace graphite anodes. The energy density of Tesla's 21700 lithium battery is only 300Wh/kg, which has reached the ceiling of lithium batteries. It is difficult to break through this bottleneck. However, 300Wh/kg is only the starting level of solid-state batteries. The energy density of slightly stronger solid-state batteries can Reach 500Wh/kg.

Xin Li, associate professor of materials science at SEAS, said that the capacity density of lithium metal anode batteries can reach ten times that of commercial graphite anode batteries, significantly improving the cruising range of electric vehicles.

At the same time, the new solid-state battery developed by the team also supports super-fast charging. It can be fully charged in about 10 minutes. The charging speed is comparable to that of the 5C Kirin battery, and the health level is still above 80% after 6,000 charges and discharges.

A solid-state battery pack with a range of 1,000 kilometers may weigh less than 300kg and take up less space, which will help car companies make full use of the space in the car. Currently, many cars adopt a canopy design, and one of the reasons is the battery. Many battery stacks are crowded at the bottom of the vehicle, and the roof adopts a traditional design, which may lead to insufficient space inside the car or the overall body height and poor appearance.

The high energy density of solid-state batteries can fully liberate car companies' design capabilities, giving electric vehicles greater room for improvement in terms of power, appearance, practicality, and comfort.

Domestic and foreign research on solid-state batteries has been ongoing for many years. Some time ago, Toyota also announced a new generation of solid-state batteries, which claim to have an energy density up to seven times that of traditional ternary lithium batteries and a range of 1,000 kilometers after ten minutes of charging.

The commercial node for solid-state batteries has arrived, and pure electric vehicles with a range of thousands of kilometers are not far away. But is that really what happened?

Commercial use is close at hand, but it cannot benefit the public

Are solid-state batteries far away from us? Not far away! Of course, it also depends on the car companies. Toyota's solid-state batteries are expected to be commercialized from 2027 to 2028. Most solid-state batteries of other overseas car companies will also be commercialized around 2028.

Domestic new energy car companies have always been active and do not intend to wait for overseas car companies. SAIC plans to commercialize solid-state batteries in 2024. The first brand of this battery will be Zhiji Automobile. Changan Automobile plans to realize the commercial use of solid-state batteries in 2025. Automobile companies such as GAC, Chery, and NIO also accelerate solid-state battery technology development. 2025 may be "the first year of China's solid-state batteries."

It should be noted that the initial solid-state battery technology is not mature enough, and the energy density may be only 300Wh/kg~500Wh/kg, which can be twice that of ternary lithium batteries. In the later period, with the advancement of technology, solid-state batteries with higher energy density will gradually be commercialized.

However, no matter how excellent solid-state batteries' energy density and safety performance are, they are not affordable for most domestic consumers.

The biggest problem hindering the commercial popularity of solid-state batteries is not the technical difficulty but the ultra-high cost of the product. NIO's 150kWh semi-solid-state battery costs about 220,000-250,000 yuan. The cost of all-solid-state batteries is even higher. One battery can buy an ideal L7 Air.

Although production costs can be reduced to a certain extent through mass production, the cost of materials cannot be overcome. Solid-state batteries are destined only for high-end products above 500,000 yuan (including solid-state battery packs).

The good news is that in 2023, the University of Science and Technology of China developed a new solid-state electrolyte-lithium zirconium oxychloride. Its electrolyte costs about 4% of that of mainstream sulfides and rare-earth-based and indium-based chlorides, and the number of charge and discharge times can reach 2000 times (battery health is not less than 80%). Developing and verifying batteries from the laboratory to the production line often takes several years. Testing whether the zirconium oxychloride lithium electrolyte can be commercialized will take time.

In addition, with the upgrade of lithium mining and smelting technology in recent years, lithium resource prices have continued to fall. However, the mineable lithium ore resources are ultimately limited. The share of electric vehicles will continue to increase in the future, and lithium ore price increases are inevitable. These solid-state batteries are also lithium batteries, and their costs will inevitably rise with the increase in lithium mine prices.

Therefore, in addition to solid-state lithium batteries, car companies, and power battery companies need to consider joining the research and development of solid-state sodium battery technology.

Are solid-state sodium batteries a better choice for the future?

2023 is the first year of the production of sodium-ion batteries in China, and cars equipped with sodium-ion batteries have gradually rolled off the production line. Compared with lithium, sodium is more abundant on Earth and costs relatively low. The main problem with current sodium-ion batteries is that their energy density is too low.

As early as 2020, the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences announced a solid-state sodium battery with high energy density, long life, and low-cost advantages. After the battery is discharged 535 times, the energy density still remains at 355Wh/kg. Although lower than solid-state lithium batteries developed by other research institutions, they are already higher than ordinary ternary lithium batteries.

The Institute of Physics of the Chinese Academy of Sciences (Beijing National Research Center for Condensed Matter Physics) and the Qingdao Institute of Energy of the Chinese Academy of Sciences have also proposed some solid-state sodium battery solutions. In 2023, Guangzhou Haowei New Energy Technology Co., Ltd. announced investing 10 billion in Chongqing Yuan to establish a solid-state sodium battery production line.

GGII Consulting Company of Gaogong Industrial Research Institute predicts that at this stage, (semi-) solid-state sodium-ion batteries are still in the early stages of development. With the increase and breakthroughs in patented technology reserves, (semi-) solid-state sodium-ion batteries are expected to achieve large-scale mass production in 2026-2027.

The energy density of solid-state sodium batteries cannot catch up with solid-state lithium batteries in a short time. Still, the lower cost can radiate to mid-to-low-end models. In the future, mid-to-low-end vehicles will rely on high-energy-density solid-state sodium batteries to achieve a range of thousands of kilometers. In contrast, high-end models rely on solid-state lithium batteries to achieve a more extended range. This may be the best situation that both car companies and consumers are willing to see.

This article comes from the WeChat public account "Dianchetong," author Xiaoying, and 36 Krypton is published with authorization. It was edited and translated by Danny Guo.