Research on Electrochemical Responses of Lithium-Ion Battery for 3C Consumer Electronics Under Structure Damage

Cylindrical LiFePO₄ batteries are increasingly used in 3C consumer electronics, including computers, communication devices, and consumer electronic products, owing to their favorable safety characteristics, structural robustness, and stable electrochemical performance. Nevertheless, these batteries may inevitably experience mechanical deformation during manufacturing, transportation, assembly, accidental dropping, collision, or vibration, which can compromise their structural integrity and trigger coupled electrochemical degradation. In this study, the structural-damage-induced failure behavior of cylindrical LiFePO₄ batteries for 3C consumer electronics was systematically investigated at 25 °C under different states of charge. By integrating mechanical response, in situ open-circuit voltage, surface temperature, and electrochemical impedance spectroscopy, the evolution of electro-mechanical failure during external loading was quantitatively characterized. The results reveal a pronounced State-of-Charge (SOC) dependent failure mechanism: the initial yield load increases with increasing state of charge, indicating improved resistance to mechanical deformation, whereas electrical failure occurs earlier at higher states of charge, accompanied by abrupt voltage collapse, abnormal voltage rebound, and unstable voltage oscillations. This phenomenon demonstrates a clear decoupling between mechanical strength and electrochemical stability under structural damage, suggesting that a higher state of charge enhances the apparent load-bearing capability while simultaneously aggravating internal electrical instability. These findings indicate that mechanical deformation thresholds alone are insufficient for evaluating the safety of LiFePO₄ batteries used in 3C consumer electronics, and that state of charge, voltage evolution, thermal response, and impedance variation should be jointly considered. This work provides mechanistic insight and experimental guidance for safety assessment, structural protection, and damage-tolerant design of LiFePO₄ batteries in portable electronic devices and other 3C consumer electronics applications.