Flamastop employee cover a car with lithium ion accumulator to prevent fire outbreak

What do you need to know about the lithium-ion accumulator (or battery) in an electric vehicle?

The lithium-ion battery, or accumulator, is the most efficient model available today. It is rechargeable and has a high energy density. Introduced to the market about thirty years ago, they were originally used mainly in electronic devices. Since then, its use has spread and it can now be found in electric vehicles.  

It transforms chemical energy into electrical energy and consists of several cells:

  • An anode, which is a negative electrode; 
  • A cathode which is a positive electrode; 
  • A separator, placed between the two electrodes to prevent short circuits, that is permeable to lithium ions; 
  • An electrolyte, often in liquid form, that allows lithium ions to move between the anode and cathode.

Such a battery is therefore able to store, accumulate and release energy. This is a real advantage, but it also carries a number of risks. That’s why it’s important to always follow the instructions for use and to be vigilant when storing, handling and recycling a lithium ion battery.

How does this battery work?

Its functionality is based on alternating : 

  • Charging cycles, when the battery receives energy from an external source; 
  • Discharge cycles, when the battery powers the engine of an electric vehicle.  

During discharge, the anode emits electrons that are absorbed by the cathode to provide energy. During charging, the process is reversed. The electrons emitted by the cathode are absorbed by the anode.  

In this way, the battery works by the constant movement of lithium ions between the electrodes. 

What are the advantages and disadvantages of a lithium-ion battery?

A highly advanced technology, the lithium-ion battery: 

  • Is suitable for a wide range of applications, as it can be found in smartphones as well as electric machines and vehicles; 
  • Has a long life when used properly; 
  • Provides high current, for example to power a car engine; 
  • Has a high energy density, allowing it to store 3 to 4 times more energy per unit mass than other technologies.

But it’s not without its downsides: 

  • It’s prone to fire and thermal runaway in the event of overheating. This can be caused by a shock or short circuit; 
  • Is sensitive to low and high temperatures, which can cause instability; 
  • Difficult to completely dispose of and recycle at the end of its life.

Despite a few weak points, the lithium-ion battery is still very efficient.  

How to use the battery of an electric vehicle properly? 

The lithium in this type of battery is highly reactive. As a result, you must be vigilant at every stage of its life: during transportation, storage, use, recharging, recycling … etc. This is a matter of strict compliance with the manufacturer’s instructions and with fire safety regulations. For example 

  • Always use the correct charger; 
  • It must also be stored in a special facility; 
  • If a lithium-ion battery is defective, it must not be used, as it may overheat, e.g. due to water ingress, and cause a fire.