#TIL: Seven stages of an EV battery

By Shilpi Samantray

A battery is the most critical part of an electric vehicle and constitutes almost 40% of the total cost of the vehicle. In comparison to a smartphone, an enormous amount of power is required to operate an electric vehicle and key components in a battery are cells, modules, and packs. That’s the reason why an EV battery is big in size, needs more power and comprises thousands of cells.

This piece throws light on the seven stages involved in the lifecycle of an EV battery.

1. Component production: This includes the manufacture of the anode, cathode, active materials, binder, electrolyte, and separator.
2. Cell production: This stage involves the production and assembly of single cells. The cell in the battery contains electrodes (anode and cathode), separator and electrolyte. All of these are inserted into a rectangular aluminum case to form a battery cell. It is the basic unit of a battery that exerts energy by charging and discharging.
3. Module production: The produced cells are then configured into larger modules that involve electronic management. A battery assembly put into a frame by combining a fixed number of cells to protect the cells from external shocks, heat or vibration, forms a battery module.
4. Pack assembly: The final shape of the battery system installed to an electric vehicle forms the battery pack. It is composed of modules and various control/ protection systems including a battery management system (BMS), a cooling system etc. E.g.: 8 modules (12 cells per module) go into one battery. Pack assembly includes installation of modules together with systems that manage power, charging and temperature.
5. Vehicle integration: This involves the integration of the battery pack into the vehicle structure. This will vary from vehicle to vehicle and is based on the battery-vehicle interface determined by the type of connector, plugs, and mounts used.
6. Usage: This includes the period in which the battery is used in the vehicle.
7. Reuse and Recycle: Usually the EV batteries degrade in the first five — six years, due to extreme operating temperature, charging/discharging rates etc. These reduced performance batteries can have a secondary life and be reused as energy-storage devices. Post which the batteries can be sent to the recycling units where they can be processed to extract valuable rare earth materials.

Figure: Stages in the lifecycle of an EV battery

Source: BCG report

Today I learnt (TIL) is a weekly series by OMI that brings you interesting nuggets of information that you didn’t know you needed.