Review of Biomimetic Engineering in the Electrolyte for Aqueous Batteries

Aqueous batteries, which replace flammable organic electrolytes with water, offer advantages such as intrinsic safety, low cost, and environmental friendliness, making them well-suited to the energy storage needs driven by the increasing proliferation of renewable energy. However, their widespread adoption is hampered by the narrow electrochemical stability window of water, dendrite growth on metal anodes, and various parasitic interfacial reactions. This review proposes a unified three-part framework for biomimetic electrolytes—SEI-mimetic, antifreeze-protein-mimetic, and ion-channel-mimetic—corresponding to three mechanistic strands—water activity regulation, interfacial mechanics, and sub-nanometer transport—to organize and compare various strategies. This paper systematically reviews and evaluates the latest advances in biomimetic electrolytes. It discusses these three biomimetic concepts and their applications in different battery chemistries (monovalent and multivalent metal systems, as well as aqueous redox-flow batteries). It also proposes a roadmap and engineering thresholds for both basic research and commercialization.