Carbon-free Cu/SbxOy/Sb nanocomposites with yolk-shell and hollow structures as high-performance anodes for lithium-ion storage

Abstract We report a simple approach for synthesizing Cu/SbxOy/Sb nanocomposite materials possessing yolk-shell structures for use as novel anode materials for Li-ion batteries. The nanocomposites were synthesized by a galvanic replacement reaction between Cu2+ ions and Sb in triethylene glycol solvent at a desired temperature. The properties including morphology, composition, and structure of the as-prepared nanocomposites were investigated using advanced characterization techniques, from which yolk-shell structures with a uniform size and morphology were observed, whereas some unconsumed Sb on the outside of the yolk was covered by the shell. The Cu/SbxOy/Sb nanocomposites presented high specific capacity, good cycling stability, and rate performance, resulting in a synergistic effect between the unique nanostructures of the composites and the inactive Cu material, which promotes stabilization of the electrode structure and enhances the kinetics of the electrochemical reaction. Specifically, the Cu/SbxOy/Sb-0.5 h yolk–shell electrode delivered a reversible capacity of 563 mAh g 1 at the 150th cycle at 100 mA g 1, with a notable rate capability. Therefore, the as-prepared nanocomposites are considered promising candidates as anode materials for Li-ion cells.