Polybenzimidazole functionalized electrolyte with Li?wetting and self?fluorination functionalities for practical Li metal batteries

Rough Li plating, low ionic conductivity, and thermal stability of conventional electrolytes post-primary challenges for achieving reliable high-capacity rechargeable lithium batteries, which metal is frequently proposed as the most promising anode material. Conventional low-polarity commercial polypropylene/polyethylene separators fail to support application high-energy-density anodes due their rigid physicochemical properties high reactivity metal, leading fatal dendrite formation vigorous exothermic reaction with electrolytes. Herein, we develop a Li-wetting, flame-retardant binary polymer electrolyte by functionalizing poly(vinylidene fluoride) (PVDF) nonflammable polybenzimidazole (PBI) build safe room-temperature solid-state membranes. A dendrite-free LiFePO4 cell solid (SPE) delivers discharge capacity 127 mAh g?1 at 25°C retention 87.5% after 500 cycles 0.5°C (0.15 mA cm?2). Phase-field simulations density functional theory calculations demonstrate that negatively charged benzimidazole chains PBI own superior affinity bis(trifluoromethanesulfonyl)imide (LiTFSI), shares overlapping electron anode, giving rise accelerated Li+ conduction room temperature uniform electrodeposition electrolyte/Li interface. The SPE also since heat-resistant polytetrafluoroethylene dense, heat-blocking graphitized carbon layer are formed in intense heat through dehydrogenation/fluorination PVDF under catalysis Lewis base imidazole rings decomposition PBI. No such fire-resistant mechanism ever reported