Explore the electrochemical performance of a novel metal copper–sodium battery

Exploring novel metal-metal batteries with a facile manufacturing process and low production cost is crucial for the development of next-generation energy storage systems. In this work, the electrochemical performance of a novel Cu–Na battery with Cu foil as a cathode and Na foil as an anode is explored for the first time. The Cu–Na battery exhibits good electrochemical reaction reversibility and cycling stability, which delivers a Coulombic efficiency of 61.5% under a charge capacity limitation of 0.02 mA h cm− 2 with a current density of 0.01 mA cm− 2 after 50 cycles. EIS analysis reveals that the Cu–Na battery maintains a stable electrochemical reaction resistance upon repeated cycles. The present work demonstrates that this Cu–Na battery could be a promising candidate for the next-generation energy storage system.