Oxide nanostructures hyperbranched with thin and hollow metal shells for high-performance nanostructured battery electrodes

High-performance electrochemical energy storage (EES) devices require the ability to modify and assemble electrode materials with superior reactivity and structural stability. The fabrication of different oxide/metal core-branch nanoarrays with adjustable components and morphologies (e.g., nanowire and nanoflake) is reported on different conductive substrates. Hollow metal branches (or shells) wrapped around oxide cores are realized by electrodeposition using ZnO nanorods as a sacrificial template. In battery electrode application, the thin hollow metal branches can provide a mechanical protection of the oxide core and a highly conductive path for charges. As a demonstration, arrays of Co ₃O₄/Ni core-branch nanowires are evaluated as the anode for lithium ion batteries. The thin metal branches evidently improve the electrochemical performance with higher specific capacity, rate capability, and capacity retention than the unmodified Co₃O₄ counterparts. A thin shell helps a lot. Metal oxide nanostructures wrapped with thin and hollow metal shells are fabricated to improve their lithium ion storage properties. The thin metal branches can provide a structural protection of the oxide core and a more conductive path for charge carriers. The specific capacity, rate capability, and capacity retentions are all improved.