Understanding how aging affects the safety performance of lithium-ion batteries under mechanical abuse is of great importance. In this study, pouch cell batteries with four different aging levels (0%, 10%, 20% and 30% capacity fading), which respectively represent fresh, prior-scrapped, normally scrapped and over-scrapped batteries, are prepared at 0 °C and subjected to indentation loading. Mechanical-electrical-thermal responses of these batteries are compared. Results show that aged pouch cells have right-shifted force-displacement curves, higher inflection force and higher peak force. After short circuit, voltage dropping is faster and electric energy is released in a shorter duration for aged ones, leading to a higher temperature for the whole battery cell. For cells with 30% capacity fading, the voltage dropping and temperature increasing are in a steep behavior. And the generated heat after short circuit is concentrated in the indented area, resulting a localized peak temperature of ${117}^{\circ }\mathrm{C}$. To clarify the observations, mechanical tests in the component level are carried out. Results reveal that the response changes in cell tests are mainly from the anode. Compression test of aged anode electrode shows consistent mechanical response changes with cell test. The delay of anode fracture under compression loading lead to the enlargement of the shear fracture zone, together with the formation of sharp lithium dendrite, resulting in more severe short circuit.

了解老化如何影响机械滥用下锂离子电池的安全性能非常重要。在本研究中，分别代表新鲜、先前报废、正常报废和过度报废的四种不同老化水平（0%、10%、20% 和 30% 容量衰减）的软包电池在 0°下制备。 C 并承受压痕载荷。比较了这些电池的机械-电-热响应。结果表明，老化的软包电池具有右移的力-位移曲线、更高的弯曲力和更高的峰值力。短路后，老化的电池电压下降更快，电能释放的时间更短，导致整个电池单元的温度更高。对于容量衰减 30% 的电池，电压下降和温度升高呈陡峭的行为。并且短路后产生的热量集中在凹痕区域，导致局部峰值温度为${117}^{\circ }\mathrm{C}$. 为了澄清观察结果，进行了组件级别的机械测试。结果表明，电池测试中的响应变化主要来自阳极。老化阳极电极的压缩测试显示出与电池测试一致的机械响应变化。压缩载荷下负极断裂的延迟导致剪切断裂区扩大，同时形成尖锐的锂枝晶，导致更严重的短路。