Hierarchical microspheres constructed by NiCo2O4/NiO@C composite nanorods for lithium-ion batteries with enhanced reversible capacity and cycle performance

With the progress of society, people have higher and higher requirements for energy battery anode materials. Commercial graphite electrode is limited by its specific capacity and can no longer meet people's needs. As a result, it is urgent to study high-performance anode materials for lithium-ion batteries. In this work，the sea urchin-like Co-Co Prussian blue analogue@Ni-1,3,5-Benzenetricarboxylate (Co-Co PBA@Ni-BTC) assembled from one-dimensional nanorods is prepared by a flexible one-step hydrothermal method using Co-Co PBA and Ni-BTC metal-organic frameworks as templates. Hierarchical microspheres constructed by nitrogen-doped carbon layer coated NiCo2O4/NiO composite nanorods (NiCo2O4/NiO@C) are further prepared by two-step calcination. After 200 cycles at a current density of 1 A g−1, the capacity can be maintained at 1432.8 mAh g−1 and the coulombic efficiency is up to 98.1%. When the current density reaches 5 A g−1, its capacity can still be maintained at 894.3 mAh g−1. The excellent electrochemical performance comes from the one-dimensional nanostructure and highly uniform nitrogen-doped carbon coating. This work provides new ideas for the application of metal-organic framework materials in lithium-ion battery anode materials.