Metal-ion battery cells are provided that take advantage of the disclosed “doping” process. The cells may be fabricated from anode and cathode electrodes, a separator, and an electrolyte. A metal-ion additive may be incorporated into (i) one or more of the electrodes, (ii) the separator, or (iii) the electrolyte. The metal-ion additive provides additional donor ions corresponding to the metal ions stored and released by anode and cathode active material particles. An activation potential may then be applied to the anode and cathode electrodes to release the additional donor ions into the battery cell.