Supplementary information files for Influence of geometrical manufacturing tolerances on lithium‐ion battery performance

Supplementary information for article Influence of geometrical manufacturing tolerances on lithium‐ion battery performance <br> The manufacture of lithium-ion battery cells consists of multiple production processes, all of which have tolerances that can affect cell performance. For battery packs that contain 100s or 1000s of individual cells, ensuring consistency and minimising variation between cells is important for reliability and lifetime. This study uses a numerical battery model to examine the influence of electrode coating thickness, calendering and electrode cutting tolerance on capacity, energy, resistance and voltage relaxation. Results show that electrode cutting tolerance has the largest affect upon cell performance characteristics, with calendering tolerance predominantly affecting the voltage relaxation period. For the simulated cell, the negative electrode coating tolerance mainly affects the cell capacity and energy, whereas the positive electrode coating tolerance has the most significant effect upon voltage relaxation. Multiple simulations were conducted with random tolerances of a Gaussian distribution applied to all processes simultaneously to represent a production run of 1000 cells. The resulting distribution of cell performance values is compared with manufacture datasheets to determine the expected reject rate for different tolerance SDs. For a reject rate of zero, the maximum tolerance SD must be less than 1% but need not be less than 0.5% for the geometrical parameters considered. Findings show that the electrode slitting, cutting and negative electrode coating tolerances require tighter manufacturing tolerance than calendering and positive electrode coating thickness.

文章《几何制造公差对锂离子电池性能的影响》的补充信息<br>锂离子电池单体的制造由多个生产工序组成，所有工序均存在公差，这些公差会影响单体性能。对于包含数百或数千个单体的电池组而言，确保单体间的一致性并最小化差异对可靠性和寿命至关重要。本研究采用数值电池模型，考察电极涂层厚度、压延及电极切割公差对容量、能量、电阻和电压弛豫的影响。结果表明，电极切割公差对电池单体性能特征的影响最大，而压延公差主要影响电压弛豫时间。在模拟单体中，负极涂层公差主要影响电池容量和能量，正极涂层公差则对电压弛豫具有最显著的影响。研究开展了多项模拟，对所有工序同时施加高斯分布的随机公差，以代表1000个单体的生产批次。将所得的电池性能值分布与制造数据表进行比较，以确定不同公差标准差（SD）下的预期不合格率。若要实现零不合格率，所考虑几何参数的最大公差标准差必须小于1%，但无需低于0.5%。研究发现，电极分切、切割及负极涂层公差需要比压延和正极涂层厚度更严格的制造公差。