Electrochemical properties of Ba(MnPO4)2·H2O in alkaline aqueous electrolytes

Ba(MnPO4)2·H2O and Ba(MnPO4)2·H2O/carbon composites were synthesized by a hydrothermal process and their electrochemical properties were evaluated in 1 M KOH aqueous solution. Ba(MnPO4)2·H2O mixed with carbon particles (BMP/Cmix) showed a reversible capacity of 54 mAh g−1 in a potential range of −0.3∼+0.5 V. Although it showed a large irreversible capacity when measured in −1.0∼+0.6 V, a structural change into Mn3O4 occurred. Ba(MnPO4)2·H2O/ carbon composites (BMP/Ccom) showed a good cycling performance and kept larger capacities than BMP/Cmix at high current densities above 1000 mA g−1.