铝箔柔软度的测试方法及其影响因素研究

Study on the test method and influencing factors for the softness of aluminum foil

锂离子电池用软包装铝塑膜对铝箔的综合性能要求较高,铝塑膜生产厂对铝箔的柔软度提出了要求,但铝箔的柔软度目前尚无明确定义和测试方法。因此,开发了适用于铝箔柔软度的测试方法,将铝箔在测试中下压8 mm深度过程中产生的最大阻力的倒数定义为铝箔的柔软度,成功表征了不同铝箔之间的柔软度差异。基于以上方法,研究了铝箔微观组织对铝箔柔软度的影响规律及其作用机制。研究结果表明:降低铝箔表面粗糙度,摩擦阻力减小,可以提高铝箱的柔软度;随着铝箔的立方织构比例增加,铝箔本身的弹性模量减小,铝箔的柔软度逐渐增加;随着铝箱晶粒尺寸增加,其屈服强度降低,铝箔的柔软度相应增加。

The flexible packaging aluminum-plastic film for lithium-ion batteries has a high requirement on the comprehensive performance of aluminum foil.The downstream customers further put forward requirements on the softness of aluminum foil.However,there is no clear definition and test method for the softness of aluminum foil.Thus,a test method is developed to measure the softness of aluminum foil,which successfully characterizes the difference in the softness between different aluminum foils.The softness of aluminum foil is defined by the reciprocal of maximum resistance produced during pressing down by 8 mm in depth.Based on the above method,the effects of microstructure on the softness of aluminum foil and its mechanism are studied.It shows that reducing surface roughness and frictional resistance can improve the softness of aluminum foil;with the increase of cubic texture,the elastic modulus of the aluminum foil itself decreases while the softness of aluminum foil increases;the increase of the grain size of the aluminum foil leads to the decrease of yield strength,which improves the softness of aluminum foil.