Electrochemical Performance of Electrodeposited Zn₄Sb₃ Films for Sodium-Ion Secondary Battery Anodes

We report the electrodeposition of zinc-antimony composite films from aqueous solution. We show that it is possible to produce Zn4Sb3 films on zinc substrates by low-temperature annealing and we evaluate their performance as sodium-ion battery anodes. Near complete utilization of the antimony (>90%) during cycling, good cycle life (>250 cycles), and high rate performance is demonstrated for Zn4Sb3 thin films. Interestingly, when Zn4Sb3 transforms in situ to an amorphous zinc-antimony composite, it shows superior performance to zinc-antimony composites that are initially amorphous. This demonstrates the importance of the initial electrode structure on promoting the sodium alloying reaction.