Polymers Bearing Catechol Pendants as Universal Hosts for Aqueous Rechargeable H⁺, Li-Ion, and Post-Li-ion (Mono-, Di-, and Trivalent) Batteries

Organic electrode materials capable of reversible coordination/uncoordination of both mono- and multivalent ions in aqueous electrolytes are desired to develop safe, sustainable, and cost-effective water-based batteries. Here, we demonstrate the universality of bioinspired redox-active polymers bearing catechol pendants to reversibly coordinate/uncoordinate numerous cations including H+ and Li+ to Zn2+ and Al3+ with fast kinetics and ultralong cyclability. This unprecedented versatility is based on a catecholato–metal cation complex (Cat2–(mMn+)) charge storage mechanism that dictates the overall electrochemistry: formation of stronger complexes in M+ < M2+ < M3+ order resulted in a huge redox potential increment that might be used to tune the operating voltage of the battery.