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

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, im-proving 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.(c) 2022 Elsevier B.V. All rights reserved.