Ni-enhanced Co3O4 nanoarrays grown in situ on a Cu substrate as integrated anode materials for high-performance Li-ion batteries

Abstract

A two-step strategic approach was proposed to synthesize three-dimensional Co₃O₄ nanoarrays fabricated on a Cu substrate surface with a Ni layer as the interface. Firstly, a Ni-nanoseed-layer was prepared on a Cu substrate by electrodepositing Ni. And then Co₃O₄ nanoarrays were in situ grown on the Ni layer via a hydrothermal synthesis. The as-obtained materials were used directly as anodes for Li-ion batteries, and the electrodes maintained a high capacity up to 1150 mA h g⁻¹ at 0.1 C after 30 cycles, and showed an excellent cycling stability and rate capability. The good electrochemical performance is owing to the pre-electrodeposited Ni-nanoseed-layer, because the Ni layer could improve the mechanical adhesion between Co₃O₄ nanoarrays and substrates effectively and increase the conductivity of anodes, without applying binders or conductive additives. This strategic in situ synthesis method will probably open a new avenue for the development of integrated electrode materials for high-performance Li-ion batteries.