Gradient electrodeposition enables high-throughput fabrication and screening of alloy anodes for high-energy lithium-ion batteries

Alloy anodes provide high capacity for high-energy lithium-ion batteries. Multi-element alloys require high-throughput fabrication technologies to facilitate the screening of alloy composition, morphologies, and structures. Here, we report a gradient electrodeposition method to prepare Sn–Co–Sb alloy anodes with varied Sn:Co:Sb ratios and demonstrate the effectiveness of gradient electrodeposition on alloy anode development. Using this technology, we can vary each metal element to form a gradient distribution in one direction by tilting the sample alternatively during each electrodeposition. Such gradient electrodeposition realizes the complex composition of Sn–Co–Sb alloys in one large sample, enabling high-throughput fabrication simultaneously. After annealing, the obtained Sn–Co–Sb alloy forms varied phases such as Sn, SnSb, and CoSn2. It is noted that the elemental ratio has a significant influence on the microstructures and electrochemical performances of the deposited Sn–Co–Sb alloy. The Sn–Co–Sb alloy with a ratio of 71.3:12.8:15.9 delivers a high reversible capacity of 671.8 mAh g−1 and simultaneously shows excellent cyclability, which can be attributed to the optimal morphology structure and Sn:Co:Sb ratio. The optimized alloy can maintain a high capacity without sacrificing cyclability, which was usually limited by strain accumulation caused by high capacity. This work reports a general gradient electrodeposition technology for high-throughput screening of alloy anodes, which can also be applied to other alloy applications.