A self-supporting P-doped CNT@MnCo2O4/Co3O4 electrode with ion and electron-conductive hierarchical structure for high performance supercapacitor

Abstract

It is an important method to enhance the electrochemical performance of metal oxide electrode by phosphorus doping in the research of high-performance hybrid supercapacitors. Herein, we obtain a P-doped carbon nanotubes (CNT)@MnCo2O4/Co3O4 film by an in-situ synthesis and subsequent phosphating. By introducing P heteroatoms, the electronic structure of MnCo2O4/Co3O4 can be effectively modulated, thereby improving the electrical conductivity and increasing Faraday reaction. The electrochemical tests show that the capacity and rate performance of CNT@MnCo2O4/Co3O4 have been significantly improved after phosphorus doping. The P-CNT@MnCo2O4/Co3O4 electrode displays an acceptable specific capacitance of 1064.4 F g−1. Furthermore, a supercapacitor P-CNT@MnCo2O4/Co3O4//activated carbon possesses 46.4 W h kg−1 of energy density at 800 W kg−1. After 10000 repeated tests, the device keeps 85.0 % of the original capacitance. The above results show that the P-doped CNT/metal oxide film we designed has some inspiration on the design of energy storage electrode materials.