What’s in an electric car battery?

Electric cars are booming, and you may be wondering what’s in their battery? Let’s take a look.

THE electric vehicle batteries all adopt lithium-ion technology. But they differ in the materials they use.

How it works ?

All the batteries lithium-ion are based on the same principle: multiple cells each containing two electrodes (anode and cathode) separated by a conductive substance, the electrolyte. Lithium-ion batteries differ in the materials making up their cathode (the electrode receiving the electrons during charging), each chemistry having its advantages and disadvantages.
Chemistry NMC (nickel-manganese-cobalt) offers the best performance in terms of energy density (amount of electricity that the battery can store) and recharge. Expensive, it presents a risk of thermal runaway (fire): several cases of spectacular fires have in fact been recorded.
Chemistry LFP (lithium-iron-phosphate) ensures better stability and lower costs, in addition to greater durability in number of charge/discharge cycles. But its energy density is lower.
Finally, a new type is emerging in China, the sodium-ionInexpensive, because they do not require so-called “critical” minerals such as manganese or cobalt, they display performances close to those of LFPs.

Electric car battery: in use

While NMC chemistry has long been popular with manufacturers, the price war is pushing them to adopt the technology LFP entry-level. It is used by the Tesla Model 3 and Y Propulsion and the Citroën ë-C3.
Some manufacturers, such as Stellantis, are banking on the technologies of the future: the Franco-Italian manufacturer recently formed a partnership with the French start-up Tiamat, jointly with the world leader in chemistry Arkema, for the Development of sodium batteriesTheir joint project is to set up a factory with a capacity of 5 GWh, entirely dedicated to the production of sodium batteries.
Investing in sodium batteries represents a long-term strategy to overcome cobalt and lithium supply constraints. This alternative could not only reduce costs, but also offer better low-temperature performance and faster recharge capability.

Other players are interested in this technology, such as the Swedish battery specialist Northvolt, which plans to open a factory in Germany, or the Chinese giant CATL, which has already launched a first generation of sodium-ion batteries in 2021.