Grass-like Co3O4 nanowire arrays anode with high rate capability and excellent cycling stability for lithium-ion batteries

Grass-like Co3O4 nanowire arrays (NWAs) directly grown on Ti foil were synthesized via a facile hydrothermal process and subsequent thermal treatment. The as-prepared Co3O4 NWAs are constructed by numerous randomly oriented nanowires. The diameters of the nanowires are in the range of 70 to 100 nm, with lengths of several micrometers. Notably, as an anode material for lithium-ion batteries (LIBs), the grass-like Co3O4 NWAs exhibit excellent electrochemical performance including outstanding rate capability and long cycle life. A remarkable capacity of 662 mAh g−1 is achieved even at a high current density of 5000 mA g−1. The specific capacity of grass-like Co3O4 NWAs could also maintain 1031 mAh g−1 at a current density of 500 mA g−1 after 100 cycles without capacity decay. The excellent performance is attributed to efficient electron transport from the Co3O4 nanowires to the current collector, good solid contact with the substrate and stable cross-linked structure formed after repeated charge-discharge cycles.