方形铝壳磷酸铁锂电池在过充等条件下容易造成电池内短路,严重威胁储能电站的安全运行.该文搭建了电池过充热失控多参量特性原位测试平台,将电池放置在模组壳内部试验以模拟实际电池的静态封闭环境,采用设计的气体原位监测系统监测CO、CO2、H2 3种气体的体积分数,使用高温电阻应变片测量电池过充膨胀形变.研究了不同充电倍率、不同容量电池的过充热失控现象与电压、温度、产气、形变特征;针对电池热失控抑制问题,设计了基于热敏绝缘材料的自触发电池热失控抑制装置.结果表明:方形铝壳磷酸铁锂电池通常在防爆阀开启前数秒可以检测到少量 CO 和 H2;电池中间首先出现膨胀形变,检测到形变至少比检测到气体早 243 s,至少比电池短路提前248 s,表面形变可作为电池过充热失控预警的有效指标;设计的自触发电池热失控抑制装置可以将电池过充热失控最高温度从358.80℃降低到259.06℃,装置同时兼具体积小、成本低、无需供电且反应后不影响其他电池等优势,可有效实现储能电站的分布式热失控抑制.研究成果对磷酸铁锂储能电站安全预警具有重要意义.
Overcharge Thermal Runaway Multi-parameter Characteristics and Thermal Runaway Suppression Technology of Lithium Iron Phosphate Energy Storage Battery
The square aluminum-shell lithium iron phosphate battery is prone to internal short circuit under overcharge and other conditions,which seriously threatens the safe operation of the energy storage power station.An in-situ testing platform for overcharge thermal runaway multi-parameter characteristics of battery was built.The battery was placed in-side the module shell for testing to simulate the static closed environment of the actual battery.The designed in-situ gas monitoring system was used to monitor the concentration of CO,CO2,and H2,and the high-temperature resistance strain gauge was used to measure the overcharge expansion deformation of the battery.The overcharge thermal runaway phe-nomenon and the characteristics of voltage,temperature,gas production and deformation of batteries with different charging rates and capacities were studied.Aiming at the problem of battery thermal runaway suppression,we designed a self-triggering battery thermal runaway suppression device based on thermal sensitive insulating material.The results show that a small amount of CO and H2 can be detected in the square aluminum-shell lithium iron phosphate battery in a few seconds before the explosion-proof valve is opened.The expansion deformation first appears in the middle of the bat-tery,and the deformation is detected at least 243 s earlier than the gas is detected,and at least 248 s earlier than the battery short circuit.The surface deformation can be used as an effective indicator for early warning of battery overcharge ther-mal runaway.The designed self-triggering battery thermal runaway suppression device can reduce the maximum temperature of battery overcharge thermal runaway from 358.80℃to 259.06℃.At the same time,the device has the advantages of small size,low cost,no power supply and does not affect other batteries after reaction,which can effective-ly realize the distributed thermal runaway suppression of the energy storage power station.The research results are of great significance for the safety warning of lithium iron phosphate energy storage power station.
lithium iron phosphate batteryoverchargethermal runawaydeformationthermal runaway suppression
万方数据
维普
