High-rate and long-life lithium-ion battery performance of hierarchically hollow-structured NiCo₂O₄/CNT nanocomposite

Graphical abstract: Carbon nanotube supported hollow structured NiCo₂O₄ nanoparticles with interconnected pores were fabricated via a simple one-pot method which possess excellent charge storage kinetics and exhibited ultra-high discharge/charge stability for 4000 cycles at a high-rate current density of 5 A g⁻¹, when used as anode material for the lithium ion battery. Display Omitted -- Abstract: 3D-transition binary metal oxides have been considered as promising anode materials for lithium-ion batteries with improved reversible capacity, structural stability and electronic conductivity compared with single metal oxides. Here, carbon nanotube supported NiCo₂O₄ nanoparticles (NiCo₂O₄/CNT) with 3D hierarchical hollow structure are fabricated via a simple one-pot method. The NiCo₂O₄ nanoparticles with interconnected pores are consists of small nanocrystals. When used as anode material for the lithium-ion battery, NiCo₂O₄/CNT exhibits enhanced electrochemical performance than that of Co₃O₄/CNT and NiO/CNT. Moreover, ultra-high discharge/charge stability was obtained for 4000 cycles at a current density of 5 A g⁻¹. The superior battery performance of NiCo₂O₄ nanoparticles is probably attributed to the special structural features and physical characteristics, including integrity, hollow structure with interconnected pores, which providing sufficient accommodation for the volume change during charge/discharge process. Besides, the consisting of ultra-small crystals enhanced the utility of active material, and intimate interaction with CNTs improved the electron-transfer rate.