Gradient Electrodeposition Enables High-Throughput Fabrication and Screening of Alloy Anodes for High-Energy Lithium-Ion Batteries

Abstract 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, and Sb ratio 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 form varied phases like 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.