Rod-like MnMoO4 positive electrode with Ni doping-induced oxygen vacancies and modified CNTs negative electrode synergistically constructing a high-performance asymmetric supercapacitor
摘要
In this study, nickel-doped rod-like manganese molybdate electrode materials were prepared via a microwave-assisted hydrothermal method. Nickel doping can effectively enhance the conductivity and charge transfer rate of the material; simultaneously, it promotes electrolyte penetration and ion transport by inducing oxygen vacancies and lattice defects. Moreover, the rod-like structure not only increases the specific surface area and improves the structural stability of the material but also provides more channels for ion transport, thereby accelerating the electrochemical reaction rate and enhancing cycling stability. Results from three-electrode tests show that the nickel-doped rod-like manganese molybdate exhibits a high specific capacitance of 2157 F g− 1 at a current density of 1 A g− 1. Even after 10,000 cycles at a high current density of 15 A g− 1, the capacitance retention remains 97.6%, demonstrating excellent cycling life. Furthermore, the modified carbon nanotube composite possesses both superior conductivity and ion diffusion performance, laying a solid foundation for high-efficiency energy storage. The asymmetric supercapacitor assembled using nickel-doped rod-like manganese molybdate as the positive electrode and modified carbon nanotubes as the negative electrode achieves an energy density of 151 Wh kg− 1 at a current density of 5 A g− 1, with a capacitance retention of 97.4% after 10,000 cycles. This study provides effective ideas and methods for the design and development of high-performance supercapacitors.