Solvent-coordination-regulated gel polymer electrolyte for stable high-voltage lithium metal batteries

Gel polymer electrolytes (GPEs) represent critical components for next-generation lithium metal batteries (LMBs), combining superior ionic conductivity with enhanced safety. Nevertheless, their practical deployment remains critically hindered by the incapability to synergistically regulate polymerization kinetics, solvation configurations, and interphase chemistry. Herein, we present a solvent coordination regulation (SCR) strategy to simultaneously address such issues. The SCR strategy utilizes solvent Lewis basicity, quantified by the donor number (DN), to modulate the initiator’s Lewis acidity, thereby controlling polymerization kinetics. Within the In(OTf) 3 @DOL model electrolyte, this precise control enables high initiator loading without exothermic runaway, yielding an amorphous matrix. Furthermore, the polymerization process intrinsically drives the formation of an anion-rich solvation structure. These merits facilitate the in situ formation of a Li-In/LiF hybrid SEI and substantially enhance interfacial stability. Consequently, the Li||LiNi 0.8 Mn 0.1 Co 0.1 O 2 cells employing the SCR-GPE exhibit excellent cycling stability, with low capacity decay rates of 0.086% (0.082%) per cycle at 30 o C (–20 o C) over 400 cycles. This work provides mechanistic insights into GPE design and interfacial chemistry for stable high-voltage LMBs. • Solvent coordination design enables control over GPE polymerization and interface. • High-DN solvent modulates Lewis acidity to suppress exothermic runaway gelation. • Polymerization shifts solvation to anion-rich structures, enhancing Li + desolvation. • Li-In/LiF hybrid SEI enhances interfacial stability .