Cathode dissolution occurs predominantly by an acidic mechanism in binary lithium/potassium carbonate electrolytes having from 50 to 75 mole percent lithium carbonate. The cathode attrition can be reduced by increasing the basicity of the electrolyte. The amount of nickel, which is transported into the matrix is directly proportional to the partial pressure of carbon dioxide in the oxidant. Nickel dissolved in the electrolyte can survive passage through the electrolyte matrix to reach the anode. The proportion of dissolved nickel surviving to reach the anode compared to the nickel deposited in the electrolyte increases with increasing basicity of the melt. Because of the small quantities involved, nickel transport from cathode to anode does not appear to represent a problem with respect to cell durability. The best explanation for the results observed in these experiments is that the nickel oxide cathode dissolves in the electrolyte via two mechanisms.