Boron nitride as an “all-in-one” gelator to immobilize concentrated sulfone electrolyte towards high performance lithium metal batteries

Quasi-solid-state electrolytes obtained by gelation of liquid electrolytes are promising for use in high-safety and high-energy-density Li metal batteries (LMBs). However, the efficient development of a solid–electrolyte interface (SEI) and suppression of Al corrosion through the rational design of a gelator and liquid electrolyte remains challenging for gel electrolytes. Herein, a concentrated sulfone electrolyte possessing Li+ hopping conduction was immobilized with boron nitride (BN) as an “all-in-one” gelator via simple grinding. This method produced a BN-gel with high electrochemical stability, nonflammability, Li+conductivity, and modulus in a wide temperature range. The desolvation energy and diffusion barrier of Li+ was reduced in BN-gel, which resulted in an abundant release of “free” Li+ ions for fast ion transport. BN-gel suppresses Al corrosion and promotes the formation of a robust SEI that efficiently protects the current collector and prevents Li dendrite growth. The multifunctional merits of BN-gels endow LMBs based on LiFePO4 (LFP) and high-voltage Li(Ni0.8Co0.1Mn0.1)O2 (NCM) cathodes with excellent battery performance at room and high temperatures.