Hierarchical micro–nano hydrangea–like NiCo2O4/V2O3 free–standing anode for high–performance lithium–ion batteries

Abstract

As one of binary transition metal oxides, NiCo2O4 (NCO) suffers from several problems like self–agglomeration and drastic volume change when used as an anode for lithium–ion batteries (LIBs). Herein, we propose a facile one–step hydrothermal method combined with heat treatment to prepare a hierarchical micro–nano hydrangea–like NiCo2O4/V2O3 composite array (denoted as NCO/VO) on a nickel foam substrate as a free–standing anode for LIBs. The V2O3 is introduced to form a composite structure with NCO, improving the electronic and ionic conductivity of the electrode. The synergistic effect of porosity, composite structure and micro–nano architecture offers the electrode excellent electrochemical performance. The specific capacity of the as–prepared electrode is 1155.6 mA h g−1 after 200 cycles under the current density of 100 mA g−1, with a retention ratio of 91.02 %. When the current density rises to 1000 mA g−1, it delivers a specific capacity of 750 mA h g−1, showing excellent rate performance. This work demonstrates that NCO/VO–NF is a promising candidate anode for next–generation LIBs.