磷酸铁锂电池内部气压失控特性研究

Out-of-control characteristics of internal air pressure in LiFePO_(4) battery

针对储能电池的热失控风险,提出以电池内部气压作为判定依据,对磷酸铁锂电池经历不同滥用条件时发生的安全风险进行快速评估的方法。结果表明,在电池正常充放电状态下,电池内部气压及外壳温度发生小范围规律性波动。在过充、过放、外部短路等异常状态下,电池内部气压在预警节点急剧增大,而在相同条件下温度参数变化明显晚于内部气压的变化,且变化速率相对较小。上述研究结果不仅揭示了不同滥用条件下电池内部气压失控的特性,同时证明了以电池内部气压失控预警代替现有电池外部温度预警能够更早地识别电池安全风险,避免发生热失控及燃烧爆炸等严重的安全事故。

This paper focused on the thermal runaway risk of energy storage battery,proposed to take the air pressure out of control as the judging basis to quickly identify the safety risks of LiFePO_(4) batteries under different abuse conditions.The results show that the pressure inside the battery and the temperature of the shell fluctuates regularly in a small range when the battery is charged and discharged normally.Under abnormal conditions such as overcharge,over-discharge and external short circuit,the internal air pressure of the battery increases sharply at abnormal nodes,while the temperature parameter changes obviously later than the internal air pressure under the same conditions,and the degree of change is relatively small.The above research results not only reveal the characteristics of internal pressure runaway of batteries under different abuse conditions,but also prove that replacing the external temperature warning of existing batteries with internal pressure runaway warning can identify battery safety risks earlier and avoid serious safety accidents such as thermal runaway and combustion explosion.