Plating and Stripping of Calcium in an Alkyl Carbonate Electrolyte at Room Temperature

We report the plating and stripping of calcium metal at room temperature in a mixture of ethylene carbonate (EC) and propylene carbonate (PC) solvents using calcium tetrafluoroborate (Ca(BF4)2) as the salt. Calcium is reversibly deposited and removed over several cycles, with associated plating–stripping efficiencies of >95%. Thin layers (∼20 μm) of crystalline calcium are present as the deposits, with a stable solid electrolyte interface (SEI) forming. This work opens opportunities to realize redox active Ca metal electrodes using commercially available alkyl carbonate solvents.