Evolution mechanism of electrochemical and thermal stability for lithium-ion batteries after vehicle service: A comparative analysis on four different batteries

The performance of lithium-ion batteries (LIBs) is closely linked to their operating conditions. Current studies mainly focus on how temperature and current variations affect battery performance under standard charging/discharging conditions in laboratories. However, research on real-world in-vehicle service conditions is still limited. This study compares four LIBs used in household vehicles and taxis to analyze how in-vehicle service affects LIBs' electrochemical and stability changes. The complex mechanisms behind performance changes in LIBs after in-vehicle service are revealed through multi-angle characterization analyses. After in-vehicle service, the cathode was most strongly affected. The effects primarily involve cathode electrolyte interface film thickening, transition metal dissolution, active material degradation, and increased crystal defects, ultimately leading to lattice disorder. The effects on the anode primarily include lithium plating, material detachment, cracking, and solid electrolyte interface film reduction thickness. After in-vehicle service, there was no significant change in the thermal stability observed for these four different batteries. Overall, the impact of in-vehicle service on batteries was multifaceted and does not follow a straightforward linear relationship. This study addresses the gap in understanding the impact of real-world vehicle aging on battery performance and its underlying mechanisms. • Four LIBs with different material systems after vehicle service were compared. • In-vehicle service has the greatest impact on the cathode material of these batteries. • Impact on the cathode includes CEI film thickening and active material damage. • Impact on the anode includes lithium plating and reduced SEI film thickness. • In-vehicle service has minimal impact on the thermal stability of the batteries.