Three-dimensional hierarchical ZnCo2O4@C3N4-B nanoflowers as high-performance anode materials for lithium-ion batteries

ZnCo2O4 has become one of the most widely used anode materials due to its good specific capacity, cost-efficiency, high thermal stability and environmental benignity. However, its poor conductivity and cycle stability have limited its practical application in lithium-ion batteries. To overcome these issues, we constructed a 3D nanoflower composite material (ZnCo2O4@C3N4-B) by combining ZnCo2O4 as a framework and B-doped g-C3N4 (g-C3N4-B) as a new carbon source material via a simple hydrothermal method. ZnCo2O4@C3N4-B exhibited exceptional specific capacitance of 919.76 mA h g−1 after 500 cycles at 0.2 A g−1 and a long-term capacity retention of 97.8% after 1000 cycles at 2 A g−1. The high reversible capacity, long cycling life and good rate performance could be attributed to the 3D interconnected architecture and doping of g-C3N4-B. This work provides a simple and general strategy to design high-performance anode materials for lithium-ion batteries to meet the needs of practical applications.