The inhomogeneous electrolyte distribution in lithium-ion batteries affects lithium-ion transfer, which attenuates battery performance and leads to thermal runaway. Moreover, real-time quantitative observations and an in-depth understanding of electrolyte wetting remain limited because of the harsh electrochemical environment. In this study, in-situ 4D X-ray computed tomography was used to monitor the electrolyte wetting by adding a contrast agent to the electrolyte. The mechanism through which the winding stress influenced electrolyte wetting was elucidated using a combination of experimental and porous-media-flow simulation methods. The winding stress was found to affect the soaking time and uniformity of the electrolyte distribution. Optimization strategies involving variable tension and pressurized injection improved the uniformity of the electrolyte wetting and shortened the electrolyte wetting time. This study provides practical guidance for the optimization of the electrolyte filling during battery fabrication.

锂离子电池中电解液的不均匀分布会影响锂离子的转移，从而削弱电池性能并导致热失控。此外，由于恶劣的电化学环境，实时定量观察和对电解质润湿的深入了解仍然受到限制。在这项研究中，原位 4D X 射线计算机断层扫描通过向电解质中添加造影剂来监测电解质润湿。结合实验和多孔介质流动模拟方法阐明了缠绕应力影响电解质润湿的机制。发现绕组应力会影响浸泡时间和电解液分布的均匀性。涉及可变张力和加压注入的优化策略提高了电解质润湿的均匀性并缩短了电解质润湿时间。该研究为电池制造过程中电解液填充的优化提供了实用指导。