Aqueous Dual-Ion Battery Based on Hematite Anode with Exposed {104} Facets.

The aqueous lithium (Li) battery is one of the most promising devices for the large-scale grid application. Currently, a key issue for aqueous Li batteries is to develop promising anode materials with favorable electrochemical performance. Here, for the first time, we demonstrate a novel aqueous Li battery that utilizes the reversible redox reaction with hydroxide ion (OH-) in the hematite (Fe2O3) anode and the commercial Li ion intercalation compound in neutral solution as the cathode. With the neutral-alkaline hybrid electrolyte, many excellent anode materials previously only working in alkaline electrolytes can now be successfully combined with commercial cathodes in neutral solutions, which may significantly enrich the species of anode material for aqueous Li batteries.