Toward Practical Solid‐State Polymer Lithium Batteries by In Situ Polymerization Process: A Review

Abstract Although there are various strategies for solid‐state polymer lithium batteries (SSPLBs) manufacturing, the most promising is the in situ polymerization process. The in situ polymerization process inherits good liquid electrolyte/electrode interfacial contact and is compatible with existing lithium‐ion batteries manufacturing processes, making it easy to achieve scale‐up production. However, most of the current studies on the in situ polymerization process are based on lab‐level coin cells, while practical pouch cells are much less studied. There is a huge difference between lab‐level coin SSPLBs and practical pouch SSPLBs. Here, as a complement to the existing reports and reviews, a systematic review of the challenges and design principles of in situ polymerization process for fabricating practical pouch SSPLBs is provided to enable a comprehensive understanding and strategic guidance for practical SSPLBs applications. This review thoroughly discusses recent advances regarding the fabrication of SSPLBs using in situ polymerization process and presents the existing challenges and future outlook for the fabrication of practical SSPLBs by in situ polymerization processes. Furthermore, the critical issues of electrode materials for manufacturing practical SSPLBs are highlighted during the in situ polymerization process, and an attempt is made to call more attention to the performance of the practical pouch SSPLBs.