Herein is reported the electrochemical performance of Na0.45Ni0.22Co0.11Mn0.66O2 as cathode material for lithium and sodium batteries. The material is able to reversibly accommodate both cation species but reveals a much better electrochemical performance towards Na-ion intercalation. Upon galvanostatic cycling for 100 cycles a much higher capacity retention (82% vs. Na, 61% vs. Li) and higher coulombic efficiency (99.5% vs. Na, 98.5% vs. Li) are shown by the sodium-based system. The worse electrochemical performance of the lithium-based system can be explained by the much higher irreversibility of the Mn3+/Mn4+ redox process.