An electrochemical device is provided having a carboranyl magnesium electrolyte. Specifically the disclosure relates to an electrochemical device having a magnesium anode, a cathode, and a current collector made of non-noble metal, and a carboranyl magnesium electrolyte. In contact with the electrolyte, the non-noble metal cathode current collector has unusually high oxidative stability>3.0V vs. a magnesium reference. Processes for making the electrochemical device are additionally provided.