Conformation inversion of succinonitrile towards long-life solid-state lithium metal batteries

Solid-state lithium metal batteries are considered as the next -generation energy storage devices, but their application is significantly hindered by poor interfacial compatibility between Li anodes and solid-state electrolytes, especially for succinonitrile (SN) based electrolyte. Herein, this issue is addressed by a conformation inversion strategy via introducing a PE separator grafted with poly -(lithium 2-acrylamido-2-methylpropanesulfonic acid) (PAMPSLi) brushes into a SN-based electrolyte. The PAMPSLi brushes inverse the conformation of SN molecules through the multiple interactions between -SO 3 Li and cyanide groups, alleviating the corrosion reactions of SN on Li anodes. Significantly, the PAMPSLi brushes regulate Li + transport pathway with the inversed SN molecules at the anode/electrolyte interface to achieve uniform Li deposition. Notably, the PAMPSLi brushes contribute to a solid electrolyte interphase (SEI) film rich in LiF and Li 3 N. Consequently, the solid-state Li||LiFePO 4 batteries with the resulting electrolyte exhibit a specific discharge capacity of 115.0 mAh/g and a considerably long cycle life of 1500 cycles at 3 C. A pouch cell with a high -loading LiFePO 4 cathode (18 mg cm -2 ) also exhibits a high areal capacity and superior safety. This study provides a novel strategy for achieving a stable electrolyte/anode interface in SN-based electrolytes, which facilitates the practical application of solidstate batteries with long life and high energy density.