Helical Branched Gel Polymer Electrolytes for 4.6V‐Class Lithium Metal Batteries

Abstract Gel polymer electrolytes (GPE) have emerged as a forefront in high‐energy‐density lithium metal batteries leveraging their solid–liquid synergy. Current strategies to enhance GPE performance predominantly focus on solvation structure optimization through solvent formulation adjustments, yet they often overlook the critical role of polymer matrix molecular topology in dictating ion solvation geometry and transport kinetics. To address this gap, a helical branched molecular topology engineering strategy is introduced. By exploiting in situ copolymerization of a spirocyclic ether monomer (3,9‐divinyl‐2,4,8,10‐tetraoxaspiro[5.5]undecane) with a multifunctional acrylate crosslinker, a helical branched polymer network is precisely constructed. These architectures induce charge‐synergistic anion localization within helical ion channels, thereby accelerating Li‐ion transport while promoting the formation of a LiF‐rich interphase to suppress lithium dendrite growth. Meanwhile, solvation structure regulation via topological confinement mitigates solvent oxidation and transition metal dissolution at high voltages (4.6 V). The engineered GPE enables exceptional electrochemical performance in Li||LiNi _0.8 Co _0.1 Mn _0.1 O ₂ cells, including 72.9% capacity retention over 500 cycles at 4.6 V. Practical 6 Ah pouch cells (485 Wh kg ⁻¹ ) achieve stable high‐voltage cycling under lean‐electrolyte of 2 g Ah ⁻¹ and low N/P ratio of 2.5. This work establishes molecular topology as a transformative design paradigm, paving the way for high‐voltage lithium metal batteries.