An Aqueous Dual-Ion Battery Cathode Of Mn3o4 Via Reversible Insertion Of Nitrate

We report reversible electrochemical insertion of NO3- into manganese(II, III) oxide (Mn3O4) as a cathode for aqueous dual-ion batteries. Characterization by TGA, FTIR, EDX, XANES, EXAFS, and EQCM collectively provides unequivocal evidence that reversible oxidative NO3- insertion takes place inside Mn3O4. Ex situ HRTEM and corresponding EDX mapping results suggest that NO3- insertion de-crystallizes the structure of Mn3O4 Kinetic studies reveal fast migration of NO3- in the Mn3O4 structure. This finding may open a new direction for novel low-cost aqueous dual-ion batteries.