Ion Transport in Polymer‐Rich Soft Phases Offering Insights Into Soft‐Gel Electrode Batteries

Soft-gel electrodes, composed of polymer-rich matrices, function as both redox-active media and dynamic ion-conducting networks. Their unique microstructure, including hydrated polymer chains, soft-gel domains, and interconnected ionic pathways, critically governs ion transport, redox kinetics, and electrochemical stability. This review summarizes ion transport mechanisms in polymer-rich soft phases, emphasizing the roles of polymer chain dynamics, crosslinking, network connectivity, hydration, and polymer-ion interactions. Microstructural features such as soft-gel domains, porosity, swelling, and interface engineering are discussed in relation to polarization, voltage stability, and cycling performance. Design strategies inspired by gel polymer electrolytes, including dual-network architectures, water confinement, polymer functionalization, and interface optimization, are highlighted. Finally, challenges in understanding local ion transport, scaling to practical systems, and integrating high-voltage or multivalent chemistries are outlined, providing a roadmap for next-generation soft-gel electrode batteries with enhanced energy density, cycling stability, and safety.