Lithium ion batteries currently offer the highest energy density. This makes them the technology of choice for powering many applications (electric vehicles, electricity storage for networks, etc.). However, these batteries are subject to performance degradation - particularly in terms of capacity and resistance - over time, even during periods of non-operation.

The performance of batteries can be determined using indicators such as SOH (State Of Health).

Among approaches currently developed, the scientific and industrial community is seeking to develop the best management strategies, taking into account the degradation of the battery's life that it induces.

Note that the initial dimensioning of a storage system is done in such a way as to ensure the service requirements of each application, even after a certain number of years of use. It therefore takes into account an ageing factor for a given lifetime. In most cases, the battery is thus oversized in relation to the energy requirement.

In most cases, and without optimized battery management, the battery is permanently brought back to full charge after use, i.e. it operates at a high state of charge. It is known that this results in premature ageing, and therefore in an increased loss of battery capacity.

Our researchers have developed a method for taking into account the state of health of a battery in the management of the maximum charge limit, in order to set up an optimal management system that ensures the service provided by the battery, while minimizing its degradation. This optimized management allows the battery to maintain the expected service and extend its life drastically (almost doubling).

This patented management method needs to be tested on a real system in order to verify its robustness.