Manganese carbonate as active material in potassium carbonate electrolyte

Abstract

In this work, we explore the possibility of using MnCO3 as active material for alkaline rechargeable batteries. K2CO3 solution is chosen as electrolyte because the solubility of MnCO3 in K2CO3 electrolyte keeps lower than that in KOH electrolyte of the same pH values, which may promote the cyclability of MnCO3. XRD and XPS measurements reveal a two-electron transfer reaction during cycling, corresponding to the conversion of MnCO3/MnO2. Further investigations demonstrate the MnCO3 electrode can be cycled 50 cycles without obvious capacity decay and the coulombic efficiency keeps over 95.0% after the 8th cycle. The present study provides a new perspective in searching new electrode materials and electrolyte systems for alkaline rechargeable batteries.