Reviving Propylene Carbonate for Lithium–Air Batteries

Propylene carbonate (PC), a staple solvent in conventional lithium-ion batteries, has long been deemed incompatible with lithium–air batteries (LABs) despite its favorable physical properties. Herein, we successfully “revive” PC by integrating stannous chloride (SnCl2) into a PC/DMSO dual-electrolyte system. Mechanistically, the solvation structure is engineered such that Sn2+ cations are preferentially solvated by DMSO and effectively incorporate and stabilize the superoxide intermediate (O2–), shielding PC molecules from nucleophilic attack of superoxide intermediates. While PC molecules exist predominantly as free solvents, slightly modulating the solvation sheath facilitates Li+ transport and mitigates the anode degradation. Consequently, this synergistic design enables the PC-based battery to achieve 255 cycles at 500 mA g–1 with a cutoff capacity of 1000 mAh g–1. This breaks the curse of LAB’s failure with carbonate-based solvents and may shed light on the design of advanced electrolyte systems for LABs.