Dual‐Phase Elastomeric Electrolyte with a Latitude‐Longitude Interwoven Structure for High‐Energy Solid‐State Lithium Metal Batteries

Abstract Solid‐state lithium metal batteries incorporating LiNi x Co y Mn z O 2 (NCM) as cathodes are developed to meet the high‐energy‐density requirements of energy storage systems. Nevertheless, the process of plating and stripping of Li‐ions on lithium metal electrodes causes significant volume changes, in which ultimately degrade battery performance. In this study, an elastomeric electrolyte with special latitude‐longitude interwoven structure is designed and synthesized successfully, which is composed of a crosslinked phase as filler and a polymeric phase as skeleton. With the increase of polymeric phase, the electrolyte changes from an irregular wrinkle structure to latitude‐longitude interwoven structure. The optimal electrolyte ATPE‐1 with a predominant latitude feature demonstrates remarkable resilience of 800% stretchability and high room temperature ionic conductivity (1.72 mS cm −1 ). Therefore, the close contact and excellent compatibility with lithium metal anode enable the lithium symmetric cell with ATPE‐1 as electrolyte to maintain a stable and extended cycle life for over 2000 h. Additionally, the existence of the supramolecular interaction between the polymeric phase and crosslinked phase effectively increases the decomposition voltage of the electrolyte. A Li/ATPE‐1/NCM622 cell delivers superior rate performance under ambient conditions. This innovative elastomeric electrolyte offers a promising potential for the practical application in high‐performance solid‐state lithium metal batteries.