Experimental investigation on mechanical-electrochemical coupling properties of cylindrical lithium-ion batteries

With the continuous improvement of safety requirements for lithium-ion batteries (LIBs), there is an urgent need to investigate the mechanical properties and failure mechanisms of LIBs. In this work, we develop an in-situ mechanical-electrochemical instrument that integrates optical imaging and infrared thermal imaging functions to study the effects of batteries mechanical abuse on its cycle lifetime, charge-discharge properties, and electrochemical impedance. The proposed instrument can realize various loading forms to simultaneously collect force, displacement, temperature, and voltage signals, and real-timely monitor the micro-damage and temperature distribution of batteries. Mechanical-electrochemical coupling experiments were conducted to investigate the impact of mechanical abuse of cylindrical compression on battery capacity and electrochemical impedance. The impact of the compressing mechanical abuse on the cycle performance of the batteries is also investigated. The experimental results provide a reference for predicting the effect of mechanical abuse on the performance of batteries.