Multi‐Hierarchical Heterostructure NiCo₂O₄/ZnCo₂O₄/CC Anode for Fast and Stable Lithium Storage

Abstract

Abstract Transition metal oxides, especially bimetal oxides, are considered as one of the most promising anode materials for high‐performance lithium‐ion batteries (LIBs) due to their ultra‐high theoretical capacity. However, it is difficult to achieve fast charging at high rates due to the issues of poor electrical conductivity, large volume expansion, and poor reaction kinetics. The design of advanced nanostructured anode materials is very important to boost lithium storage performance. Herein, the multi‐hierarchical heterostructure material NiCo 2 O 4 /ZnCo 2 O 4 /Carbon Cloth (NCO/ZCO/CC) including carbon cloth substrate, ZnCo 2 O 4 nanosheets, and NiCo 2 O 4 nanowires is prepared as a binder‐free anode for LIBs. Benefiting from the special hierarchical nanostructure and the synergistic interaction of the component, the as‐prepared NCO/ZCO/CC anode material exhibits good electrical conductivity, structural stability, and electrochemical kinetics, which can provide a high reversible areal capacity of 2.55 mAh cm −2 at 2 mA cm −2 after 200 cycles. At a high current density of 5 mA cm −2 , the NCO/ZCO/CC electrode only takes about 20 min to fully charge and it can still reach a capacity of 1.50 mAh cm −2 with a capacity retention of 86.2% after 400 cycles, revealing the potential for fast charging at high rates.