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The family of copper antimony selenides is important for renewable energy applications. Several phases are accessible within narrow energy and compositional ranges, and tunability between phases is not well-established. Thus, this system provides a rich landscape to understand the phase transformations that occur in hot-injection nanoparticle syntheses. Rietveld refinements on X-ray diffraction patterns model anisotropic morphologies to obtain phase percentages. Reactions targeting the stoichiometry of CuSbSe2 formed Cu3SbSe3 before decomposing to thermodynamically stable CuSbSe2 over time. An amide base was added to balance cation reactivity and directly form CuSbSe2. Interestingly, Cu3SbSe3 remained present but converted to CuSbSe2 more rapidly. We propose that initial Cu3SbSe3 formation may be due to the selenium species not being reactive enough to balance the high reactivity of the copper complex. The unexpected effect of a base on cation reactivity in this system provides insight into the advantages and limitations for its use in other multivalent systems. 

Alloy-based materials such as antimony (Sb) are of interest for both Li/Na-ion batteries due to their high theoretical capacity and electronic conductivity. Of the various ways to fabricate Sb films (slurry casting, sputtering, etc.) one promising route is through electrodeposition. Electrodeposition is an industrially relevant synthetic technique that allows for the use of solution additives to control different characteristics such as film uniformity, morphology, and electrical conductivity. Solution additives such as cetyltrimethylammonium bromide (CTAB) and bis(3-sulfopropyl) disulfide (SPS) have been used to control different characteristics such as particle morphology and electrical conductivity in various electrodeposits but have not been applied to the electrodeposition of Sb for battery applications. In this study, Sb films were electrodeposited with varied concentrations of CTAB and SPS and the structure, morphology, composition, and electrochemical performance in Na-ion batteries were compared. We report that CTAB and SPS additives can significantly influence electrodeposited Sb films by altering the morphology and reduce the crystallinity, affecting the electrochemical performance. These studies provide valuable insight into the tunability of alloy-based films through electrodeposition and solution additives for battery applications. 

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.