Another Way to Realize LiMn2O4 as a Solid Electrolyte

Abstract The development and application of solid‐state electrolytes (SSEs) play a crucial role in advancing lithium metal batteries (LMBs). Consequently, the search for high‐performance, economic, and easily fabricated SSEs has become a prevailing trend. In this work, we explore an alternative approach to design the traditional commercial lithium‐ion batteries cathode material, spinel‐type LiMn 2 O 4 (LMO) as a SSE. By blending LMO with poly(vinylidene difluoride) and combining with two layers of polyethylene (PE) film on the top and bottom, we effectively reduce its high electronic conductivity, thereby creating the PE/LMO/PE SSE. The PE/LMO/PE SSE demonstrates high ionic conductivity (3.15 × 10 −4 S cm −1 at 35°C), low electronic conductivity (7.31 × 10 −11 S cm −1 ), and good interfacial contact and stability with both the lithium metal anode, LiFePO 4 and nickel‐rich Li[Ni 0.8 Co 0.1 Mn 0.1 ]O 2 cathodes. This study offers a new direction for the application of the electrochemically active cathode material LMO, while providing a simple and feasible solution to reduce the electronic conductivity of SSEs. Additionally, it opens up new perspectives for selecting high‐performance SSEs for use in LMBs, paving an alternative economic path toward the commercialization of solid‐state lithium metal batteries.