Incremental capacity analysis of lithium-ion second-life batteries from electric vehicles under cycling ageing

Abstract

Nowadays, the reuse of batteries from electric vehicles is considered a promising solution to benefit from their remaining energy and extend their lifespan. Yet, the economic viability of these second-life batteries is still uncertain, and the optimization of testing at their reconfiguration stage and during their lifetime is the key to ensure their success. This paper aims to assess Incremental Capacity Analysis technique in Nissan Leaf modules during their second-life use, in order to evaluate both its potential as an State of Health estimator and as a tool to identify underlying degradation mechanisms. Despite the different internal state and ageing rates observed between the tested modules, ICA is found to be consistent at similar SOH levels. The influence of ageing, current and temperature on ICA is evaluated through an accelerated cycling test. Results show that ICA is a promising alternative to estimate SOH during second life even at currents up to C/2 and testing temperatures of 45 °C. However, testing by accelerated currents and temperatures is not recommended for the identification of degradation mechanisms.