Spontaneous Anionic Double Capture/Displacement to Trigger Single‐Ion Conducting Interpenetrating Polymer Networks with Desired Ionic Conductivity for Durable Zn Metal Batteries

The engineering of single-ion conductors (SICs) is a promising strategy to stabilize the anode/electrolyte interface in zinc-ion batteries. However, the commonly employed single-ion conductive solid or quasi-solid electrolytes often lead to a significant reduction in overall ionic conductivity, thereby impeding ion diffusion kinetics. Here, we propose a compromise strategy that effectively balances ionic conductivity and ion transference number. Specifically, a single-ion conductive interpenetrating polymer networks (IPNs) with phase-functional decoupling is developed solely on the anode side, while a liquid electrolyte is retained on the cathode side. This design facilitates a high ion transference number (0.84) while maintaining the ionic conductivity at an optimal level (12.1 mS cm^-1). The single-ion-conductive mechanism is unveiled as a spontaneous anionic dual capture/displacement process, which synergizes zincophilic-hydrophobic functionality to ensure efficient reversible Zn²⁺ stripping and plating. The modified electrode demonstrates outstanding cycling stability of 1300 h at 5 mA cm^-2. The assembled NH₄V₄O₁₀//IPNs@Zn full cell exhibits an exceptional lifespan, enduring 9000 cycles with a remarkable retention of 80.8% at 10 A g^-1. This work introduces an effective approach for balancing ionic conductivity and ion transference numbers in SICs, offering a promising pathway for the development of high-performance SICs.