Review—In Situ Polymerization for Integration and Interfacial Protection Towards Solid State Lithium Batteries

Lithium ion batteries using liquid electrolytes often face challenges of safety issues. Polymer electrolytes can effectively solve this problem. Traditional preparation of polymer electrolytes is solution-casting method, which is complicated in practical application. Simultaneously, this ex-situ polymer electrolytes prepared by conventional method exhibits poor interfacial contact with electrodes. Fortunately, the emerging in-situ polymerization of solid state polymer electrolytes simplifies the preparation and forms an integrated interface for better interfacial compatibility in solid state lithium batteries. It is certain that solid state lithium batteries via in-situ polymerization exhibit various functionality: (1) forming integrated interface to enhance interfacial compatibility; (2) inhibiting the dissolution of transition metal ions; (3) suppressing the growth of lithium dendrites; (4) Improving the cycle performance of silicon anodes; (5) inhibiting the shuttling effect of polysulfides; (6) promoting battery performance of post-lithium batteries. Therefore, the review mainly considers and discuss the up-to-date research progress and insights on scientific issues underpinning solid state lithium batteries via in-situ polymerization strategy. Moreover, the challenges and perspectives of developing solid state lithium batteries via in-situ polymerization are discussed as well. We believe that this review will shed light on scientific and practical issues in the development of high-performance solid state lithium batteries.