The electrochemical performances of Li3Cu2O4 and Li2NaCu2O4 as cathode materials in lithium coin type batteries have been studied. In Li3Cu2O4, the copper was oxidised to the III level when cycling. The replacement of the lithium by the sodium ions in the octahedral sites in Li2NaCu2O4 might have an effect on the pathway of the lithium ions during the (de)intercalations.