The role of structural defects in commercial lithium-ion batteries
Guannan Qian, Federico Monaco, Dechao Meng, Sang‐Jun Lee, Guibin Zan, Jizhou Li, Dmitry Karpov, Sheraz Gul, D. J. Vine, Benjamin Stripe, Jin Zhang, Jun‐Sik Lee, Zi‐Feng Ma, Wenbin Yun, P. Pianetta, Xiqian Yu, Linsen Li, Peter Cloeten, Yijin Liu
Abstract
The manufacturing of commercial lithium-ion batteries (LIBs) involves a number of sophisticated production processes. Various cell defects can be induced, and, depending on their structural and chemical characteristics, they could lead to acute failure and/or chronic degradation. Although tremendous efforts have been devoted to develop a robust quality control (QC) procedure, the functional role of the cell defects is not well understood. Here, we address this question through a systematic experimental study of commercial 18650-type LIBs that have failed the QC inspection due to a self-discharging effect. We identify and recover the defective regions from the cell and conduct a comprehensive investigation from the chemical, structural, and morphological perspectives. Our results reveal how the structural defects affect the cell performance, which is highly important to industry-scale battery production.