Work

Effects of ageing on thermal stability and gas emissions in lithium-ion cells regarding second-life applications

Year: 2026

Type: article

Abstract: The reuse of lithium-ion batteries (LIBs) from electric vehicles (EVs) in second-life applications such as battery energy storage systems (BESSs) offers significant environmental and economic benefits. Beyond economic considerations, safety management is a key challenge for large-scale deployment, yet the influence of ageing on LIB safety remains insufficiently understood. Preger et al., emphasized in their review the existing gap on data about electrical abuse and high-capacity cells. This laboratory-scale study investigates the evolution of key safety parameters over battery lifetime. The present study contribute to closing this gap studying three types of LIB cells (Nickel Manganese Cobalt (NMC) chemistry) from EV and hybrid EV batteries that were artificially aged and tested at three representative states of health (SOH): 100% (beginning-of-life, BOL), 80% (end of first life), and 60% (midpoint of second life). Cells were subjected to thermal abuse, overcharge, and accelerating rate calorimetry, with selected tests coupled to online gas analysis. Results show a pronounced ageing effect on thermal stability. The onset temperature of thermal runaway was reduced by 17–69 °C for aged cells (60% SOH) compared with BOL cells, while overcharge acceptance decreased by 13–78%. Although aged cells exhibited lower thermal stability, their thermal runaway reactions under inert conditions were less severe, as indicated by lower maximum temperatures. These findings highlight the need to account for ageing-induced shifts in exothermic reaction onset and thermal runaway behavior when designing safe second-life BESS. Future work should extend the analysis to LFP chemistries especially as the market is expected to shift towards this chemistry and consider battery and system levels, including influence of ageing on thermal runaway propagation.

Source: Energy Reports

DOI: 10.1016/j.egyr.2026.109240