Experimental investigation of lithium-ion battery degradation under coupled thermal and vibrational stress for enhanced state-of-health prediction

Lithium-ion batteries in transport and vibration-rich environments experience simultaneous thermal and mechanical stress, yet the combined influence of temperature and vibration on short-term ageing remains insufficiently characterised. This study quantifies coupled degradation by evaluating capacity and internal resistance of cylindrical cells cycled between −20 and 60 °C under vibrational and static conditions. In-situ discharge capacity was recorded over nine cycles, and internal resistance was measured at room temperature before and after exposure to enable direct comparison across conditions. Capacity loss was strongly temperature dependent, peaking at −20 °C where the vibrated cell showed a 2.97 % loss, while the minimum loss of 0.20 % occurred at 20 °C. Across all temperatures, vibration accelerated degradation and increased average capacity loss by approximately 1.8 times relative to static operation. Internal resistance increased by 0.05–0.28 % and followed the same temperature trend as capacity. A two-variable polynomial model represented capacity as a function of temperature and cycle number and reproduced the measured trends with good accuracy. These results demonstrate non-additive thermo-mechanical interactions and support vibration-aware state-of-health assessment for batteries in service.