Suitability of the nanophosphate LiFePO4/C battery chemistry for the fully electric vehicle: Lifetime perspective

There are currently many different lithium ion chemistries available on the market and several new players are in the research and development process; however, none of them is superior to the other chemistries in all the aspects. Relatively low price, long cycle and calendar lifetime, and intrinsic safety of the nanophosphate LiFePO₄/C lithium ion chemistry make it possible to consider this chemistry for electric vehicle applications. This paper investigates the lifetime of the nanophosphate LiFePO₄/C battery chemistry when it is used for full electrical vehicles. The investigation is performed considering a semi-empirical calendar and cycle lifetime model, which was developed based on extended accelerated lifetime tests. Both capacity and power capability degradations during calendar and cycle life ageing are considered and quantified. Finally, the developed battery cell lifetime model is used to study the capacity and power capability degradation behaviour of the tested nanophosphate LiFePO₄/C battery for two electric vehicle operational scenarios.