A silatrane:molecule‐based crystal composite solid‐state electrolyte for all solid‐state lithium batteries

All-solid-state batteries (ASSBs) are promoted as a promising option towards higher energies and power densities as well as drastically reduced safety risks as compared to conventional lithium-ion batteries (LIBs). Herein, a composite solid-state electrolyte (SSE) based on two crystalline materials with two distinctly different ion conduction mechanisms, percolation and ion hopping, is reported. By combining a silatrane (SA; here ethoxysilatrane) with a molecule-based crystal (MBC; here LiTFSI-TMEDA) the resulting SA : MBC 2 : 1 crystalline composite shows an appreciable ion conductivity of 10(-5) S cm(-1) at room temperature, and low apparent activation energy, 836 K, for the ion transport. Studies of the overall and local structure show that in the composite the Li+ and TFSI ions are dissociated, and this seems to be mediated by the SA part of the matrix. As a proof-of-concept, an ASSB based on this SSE can operate at 50 degrees C providing up to 105 mAh g(-1) during 20 cycles.