Hybrid NiO/Co3O4 nanoflowers as high-performance anode materials for lithium-ion batteries

The porous NiO/Co 3 O 4 nanoflowers were synthesized by two steps: solvothermal synthesis of NiO/Co 3 O 4 precursor followed by an annealing process. The unique flower-like nanostructure and synergistic effect of NiO and Co 3 O 4 overcome the intrinsic low conductivity of transition metal oxides and severe volume expansion during repeated lithiation/delithiation processes. This anode material shows superior reversible capacity and impressive cycling stability. • Porous in-situ hybridized NiO/Co 3 O 4 nanoflowers are fabricated. • The composite integrates favorable features of each component. • The composite exhibits high reversible capacity and impressive cycling stability. • The nanoscale design principle can be extended to other TMO-based anode materials. The construction of advanced nanostructures as well as the hybridization of different active materials are highly desirable for achieving lithium-ion batteries (LIBs) anode with superior electrochemical performance. Herein, we developed a simple solvothermal method, with a subsequent annealing process for the synthesis of flower-like NiO/Co 3 O 4 with dense pores on the petals and investigated its potential as anodes for LIBs. The as-prepared hybridized NiO/Co 3 O 4 anode material exhibited an impressive capacity (1428.8 mAh g −1 at a current density of 0.1 A g −1 after 100 cycles, and 668.6 mAh g −1 at 1 A g −1 after 600 cycles), which is a significant improvement compared with its corresponding building blocks as well as the physical mixture of NiO and Co 3 O 4 . This excellent performance is attributed to the unique flower-like porous architecture and the synergetic effect of two electrochemically cooperative anode materials, simultaneously overcoming the conductivity deficiency and capacity fading due to severe volume expansion during cycling. The material design principle and synthesis approach are expected to be useful for other battery electrodes, as well as in other applications such as catalysis, microwave absorption and gas sensing.