Unlocking High‐Voltage Li‐Metal Batteries via Additive‐Driven In Situ Semi‐IPN Gel Electrolytes With Coupled Solvation and Interphase Modulation

ABSTRACT Engineering functional additive‐tailored Li + solvation shells is viable for optimizing the conduction and interfacial behavior of gel polymer electrolytes (GPEs). However, prevailing strategies of simplistic concentration elevation may incur compromises while overlooking the polymer host's synergistic role. Here, we propose a facile additive‐coupled polymer topological confinement strategy for Li + solvation reconstruction and interfacial chemo‐mechanics optimization. An in situ semi‐interpenetrating polymer network (semi‐IPN) is constructed by integrating a rigid framework derived from tris[3‐(2‐methylaziridinyl)propionate] (TTMAP) polymerization with flexible linear PFEC chains. These chains, generated via Al(EtO) 3 ‐triggered FEC polymerization and coordinated to Al‐based clusters, are physically entangled and trapped within the rigid TTMAP skeleton. This hierarchical framework topologically confines interstitial spaces, enriching the primary Li + solvation sheath with functional FEC to expedite desolvation kinetics and extend oxidative stability. The N‐containing TTMAP species and dual additives synergistically generate a uniform SEI/CEI rich in inorganic LiF, Li 3 N, and Al 2 O 3 . Consequently, the optimized GPE delivers outstanding high‐voltage stability, retaining 84.2% capacity in Li||NCM811 after 200 cycles (1 C, 4.5 V) and 71.2% in graphite||NCM811 after 1000 cycles (1 C, 4.3 V). This work demonstrates that maximizing Li + ‐solvating additive efficacy relies on coordination regulation rather than simple concentration increase, offering a new perspective for electrolyte optimization.