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

Abstract 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 Zn 2+ stripping and plating. The modified electrode demonstrates outstanding cycling stability of 1300 h at 5 mA cm −2 . The assembled NH 4 V 4 O 10 //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.