Charging and discharging of our mobile phone battery.

Lets see how our mobile gets charged and discharged. As we all know our mobile battery is made up of lithium-ion. Lithium-ion batteries consist of different parts, making them sufficiently productive and user-friendly.

The composition of li-ion battery is as follows:

• Cathode (Positive Electrode): Cathode is majorly made from lithium metal oxides like lithium cobalt oxide (LiCoO?), lithium iron phosphate (LiFePO?), or lithium nickel manganese cobalt oxide (NMC).
• Anode (Negative Electrode): Anode is Usually composed of graphite.
• Electrolyte: A lithium salt (e.g., lithium hexafluorophosphate, LiPF?) dissolved in an organic solvent, which facilitate the movement of lithium ions between the electrodes.
• Separator: A porous membrane that prevents direct contact between the anode and cathode while allowing ion flow.
• Current Collectors: Typically made of aluminum (for the cathode) and copper (for the anode), these facilitate the flow of electrons to and from the external circuit.

Now let's see the actual charging case:

Charging Start:

• When you plug in the battery to charge, it creates an electric field across the battery's parts.

Lithium Ion Movement:

• From Cathode to Electrolyte: Lithium ions (Li?) leave the cathode (like LiCoO?) and enter the electrolyte.
• Through the Electrolyte: These lithium ions move through the electrolyte, which allows them to travel but keeps electrons from moving directly through it.

Moving to the Anode:

• Into the Anode: The lithium ions pass through the separator and go into the graphite layers of the anode, where they are stored.

Electron Flow:

• While this is happening, electrons travel from the cathode to the anode through the charger, balancing the lithium ions' charge and supplying the energy needed for their movement.

Energy Storage:

• As lithium ions build up in the anode, the battery stores energy as chemical potential energy.

In Discharging Case following scenario happens

Discharging Start:

• When the battery is used to power a device, an electric field is created in the opposite direction.

Lithium Ion Movement:

• From Anode to Electrolyte: Lithium ions (Li?) leave the graphite layers in the anode and enter the electrolyte.
• Through the Electrolyte: These lithium ions move through the electrolyte, which allows them to travel but keeps electrons from moving directly through it.

Moving to the Cathode:

• Into the Cathode: The lithium ions pass through the separator and go into the cathode material (like LiCoO?).

Electron Flow:

• While this is happening, electrons travel from the anode to the cathode through the external circuit (powering the device), balancing the lithium ions' charge and providing the energy needed for their movement.

Energy Release:

• As lithium ions move to the cathode, the stored chemical potential energy is released as electrical energy, powering the device.

In short, li-ion is playing between the cathode and anode during charging and discharging. During charging, connecting a lithium-ion battery to a charger applies an electric field. Lithium ions (Li?) move from the cathode to the anode, while electrons flow through the charger, storing energy as chemical potential.

During discharging, the electric field reverses. Lithium ions travel from the anode to the cathode, and electrons flow through the device, releasing stored energy as electrical power to run the device.

I hope this simple explaination will help you to understand the charging and discharging cases of Li-ion batteries.