锂离子电池陶瓷隔膜的热降解行为

Thermal degradation behavior of ceramic membrane for lithium ion batteries

研究了锂离子电池陶瓷隔膜的热稳定性及热降解动力学,采用热重分析法,在氮气气氛中,升温速率分别为5、10、20和30℃/min的条件下,利用Kissinger、Flynn-Wall-Ozawa、Friedman和Modified Coats-Redfern方法对隔膜的非等温热分解动力学数据进行了分析。TG曲线显示隔膜分解率达到10%和15%时,最低热降解温度分别为424.5和431.5℃;隔膜的热降解为一步法,分解的温度区间为350～520℃,热分解的表观活化能为205.25 kJ/mol。分解率达到1.0%、2.0%和5.0%时,隔膜的最低分解温度分别为354.7、377.9和409.2℃;最大转化率为68.39%,对应最低分解温度为474.4℃,而残余碳化物及氧化铝为31.61%。

The thermal stability and thermal degradation kinetics of the ceramic separator for lithium ion batteries were studied.Under the conditions of 5,10,20 and 30℃/min in the nitrogen atmosphere,the non-isothermal pyrolysis kinetic data of separators were analyzed by the Kissinger,Flynn-Wall-Ozawa,Friedman and Modified Coats-Redfern methods.TG curves show that the decomposition rate of ceramic diaphragm reaches 10%and 15%,the lowest thermal degradation temperature is 424.5 and 431.5℃,respectively.Ceramic diaphragm undergo the one-step decomposition,its decomposition temperature is in the range of 350~520℃,the apparent activation energy E of thermal decomposition is 205.25 kJ/mol.When the decomposition rate reaches 1.0%,2.0%and 5.0%,the lowest temperature of the ceramic membrane iss 354.7,377.9 and 409.2℃,respectively.The maximum conversion rate is 68.39%,corresponding to the lowest decomposition temperature is 474.4℃,while the residual carbide and alumina is 31.61%.