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Antimony (Sb) electrodes are an ideal anode material for sodium-ion batteries, which are an attractive energy storage system to support grid-level energy storage. These anodes have high thermal stability, good rate performance, and good electronic conductivity, but there are limitations on the fundamental understanding of phases present as the material is sodiated and desodiated. Therefore, detailed investigations of the impact of the structure-property relationships on the performance of Sb electrodes are crucial for understanding how the degradation mechanisms of these electrodes can be controlled. Although significant work has gone into understanding the sodiation/desodiation mechanism of Sb-based anodes, the fabrication method, electrode composition and experimental parameters vary tremendously and there are discrepancies in the reported sodiation/desodiation reactions. Here we report the use of electrodeposition and slurry casting to fabricate Sb composite films to investigate how different fabrication techniques influence observed sodiation/desodiation reactions. We report that electrode fabrication techniques can dramatically impact the sodiation/desodiation reaction mechanism due to mechanical stability, morphology, and composition of the film. Electrodeposition has been shown to be a viable fabrication technique to process anode materials and to study reaction mechanisms at longer lengths scales without the convolution of binders and additives. 

Electrodeposition of pure phase SnSb is reported for the first time. The purity of the product is important, as the impure phase is found to be detrimental to the material's lifetime as a sodium-ion anode. The directly deposited electrode was able to retain 95% capacity after 300 cycles, and only fall below 80% capacity retention after 800 cycles when cycled versus sodium. 

Electrodeposited Cu–Sb thin films on Cu and Ni substrates are investigated as alloy anodes for Li-ion batteries to elucidate the effects of both the film composition and substrate interactions on anode cycling stability and lifetime. Thin films of composition Cu x Sb (0 < x < 2) exhibit the longest cycle lifetimes nearest x = 1. Additionally, the Cu–Sb films exhibit shorter cycle lifetimes when electrodeposited onto Cu substrates when compared to equivalent films on Ni substrates. Ex situ characterization and differential capacity analysis of the anodes reveal that significant interdiffusion occurs during cycling between pure Sb films and Cu substrates. The great extent of interdiffusion results in mechanical weakening of the film–substrate interface that exacerbates film delamination and decreases cycle lifetimes of Cu–Sb films on Cu substrates regardless of the film's composition. The results presented here demonstrate that the composition of the anode alone is not the most important predictor of long term cycle stability; the composition coupled with the identity of the substrate is key. These interactions are critical to understand in the design of high capacity, large volume change materials fabricated without the need for additional binders.