过热下磷酸铁锂锂离子电池的过充电耐受性  

Tolerance to overcharge of lithium iron phosphate Li-ion battery under overheating

作　　者：姚代兵 高哲 常海涛[2] 路密 YAO Daibing;GAO Zhe;CHANG Haitao;LU Mi(School of Materials Science and Engineering,Xiamen University of Technology,Xiamen,Fujian 361024,China;Fujian Nanping Nanfu Battery Co.,Ltd.,Fujian Key Laboratory of High Performance Battery,Nanping,Fujian 353000,China)

机构地区：[1]厦门理工学院材料科学与工程学院,福建厦门361024 [2]福建南平南孚电池有限公司,福建省高效能电池重点实验室,福建南平353000

出　　处：《电池》2024年第5期660-663,共4页Battery Bimonthly

基　　金：福建省科技厅引导性项目(2022H0057)。

摘　　要：研究极端条件下的多场耦合相互作用,有助于深入理解锂离子电池的热失控机理。在85℃的过热环境下,将1380200型20 Ah软包装磷酸铁锂动力锂离子电池的过充电压从4.07 V阶梯式增加至5.42 V,电池发生气体泄压但未出现起火或爆炸,表明电池即使在过热条件下也具有较强的耐过充电能力。泄压过程中,首先检测到氢气的信号,随后检测到一氧化碳、烷烃和烯烃等易燃气体。XRD分析表明,过充电后,正极活性物质磷酸铁锂完全去锂化生成了磷酸铁。SEM结果显示,部分过充电后的磷酸铁颗粒出现裂纹,但结构未被进一步破坏,证实了磷酸铁锂的高热稳定性。Studying the multi-field coupling interaction under extreme conditions is helpful for further understanding the thermal runaway mechanism of Li-ion battery.The overcharge voltage of the 1380200 type pouch lithium iron phosphate power Li-ion battery is increased from 4.07 V to 5.42 V step by step in an overheated environment at 85℃.The battery has gas pressure relief but no fire or explosion,indicating that the battery has strong overcharge resistance even under overheated conditions.During the pressure relief process,the signal of hydrogen is first detected,then flammable gases such as carbon monoxide,alkanes and olefins are detected.XRD analysis shows that the cathode active material LiFePO_(4) is fully delithiated to form FePO_(4) after overcharging.The SEM results show that some of the FePO_(4) particles have cracks after overcharging,but the structure is not further destroyed,indicating the high thermal stability of LiFePO_(4).

关 键 词：锂离子电池 动力电池 磷酸铁锂 多因素耦合 过充电测试 过热 

分 类 号：TM912.9[电气工程—电力电子与电力传动] TD98[矿业工程—选矿]