软包锂电池铝塑膜热封强度工艺参数研究

Study on the heat-sealing process parameters of aluminum plastic film for pouch lithium battery

铝塑复合膜是锂离子电池可以实现外形尺寸灵活变化的关键,其热封性能的优劣会影响到电池在使用过程中的安全。针对152μm厚的PA/Al/CPP铝塑复合膜,研究了在不同热封条件(热封温度、热封时间和热封压力)下铝塑膜的热封强度,通过理论计算选取合理的参数范围,利用万能材料试验机测试了热封后铝塑膜能承受的最大拉伸载荷,并将此作为衡量热封强度大小的标准;根据单因素实验结果分析热封强度在不同热封工艺参数下的变化规律,并设计了正交实验,依据正交实验结果,对热封工艺参数进行显著性分析,同时通过响应曲面法拟合影响显著的参数与热封强度之间的关系,构建了热封强度关于热封温度与热封时间的数学模型。结果表明,在铝塑膜有效封合的范围内,热封温度、热封时间和热封压力对铝塑膜热封强度的增加均起着正向作用,其中影响显著的参数为热封温度和热封时间。本研究得到的模型可以为企业生产过程中热封参数的选择提供依据。

Aluminum plastic composite film is the key to achieve flexible size of Li-ion battery,and its heat-sealing performance is related to the safety in use directly.The heat-sealing strength of 152μm PA/Al/CPP Al-plastic film is studied under different conditions(heat-sealing temperature,heatsealing time and heat-sealing pressure).Reasonable parameters are selected through theoretical calculation.The maximum tensile force of the film is tested by universal material testing machine,which is taken as the standard to measure the heat-sealing strength.According to the single factor experiment results,the variation of the heat-sealing strength under different heat-sealing technological parameters is described,and the orthogonal experiment is designed.Then,the orthogonal experiment results are used to analyze the significance of the process parameters that affect the heat-sealing performance of the Al-plastic film.Response surface method was used to fit the relationship between the influential parameters and the heat-sealing strength,and the mathematical model of heat-sealing strength on the heat-sealing temperature and the heat-sealing time is established.The result shows that the three heat-sealing parameters can enhance heat-seal strength within an effective heat-sealing range,among which heat-sealing temperature and heat-sealing time are the main factors.The model obtained in this study can be used to calculate unknown parameters,which provides a basis for the selection of parameters in the production process of enterprises.