Core collapse in cylindrical Li-ion batteries

Cylindrical lithium-ion batteries are manufactured with a jelly roll structure of tightly wound electrode layers separated by separators. Core collapse occurs when multiple layers adjacent to the core of the jelly roll deform inward. This paper reviews the experimental and stress modeling analysis studies of core collapse initiation and evolution with charge-discharge cycles. Areas of agreement and conflicting opinions on the causes of core collapse are discussed. Euler and hoop buckling analysis are conducted for baseline comparison with reported causes of core collapse and mathematical modeling in the literature. Recommendations for future studies are suggested for determining the dominant factors affecting core collapse, conducting experiments to assess core collapse degradation paths, and providing suggestions for modeling.