Be it an energy generating cell or an energy consuming cell, efficiency of an electrochemical cell has traditionally been looked at as a product of voltage efficiency and current efficiency. Voltage efficiency takes care of the impact of ohmic losses in electrode and electrolyte, polarization losses at the electrode due to charge transfer reaction and polarization losses due to mass transfer limitations. Current efficiency takes care of the impact of parasitic reactions and the effective utilization of reactants. Can there be additional energy loss leading to efficiency loss that is not captured in either via voltage or via current efficiency?