Construction of Sn–Mo bimetallic oxide nanoparticle-encapsulated P-doped 3D hierarchical porous carbon through an in-situ reduction and competitive cross-linking strategy for efficient pseudocapacitive energy storage

Abstract

Efficient pseudocapacitive energy storage devices have attracted considerable attention due to the growing demand of electrical power supply. Still, the design and fabrication of electrode materials with high power and energy densities is challengeable. Herein, an in-situ reduction and competitive cross-linking strategy is presented to construct a novel Sn–Mo bimetallic oxide nanoparticle-grown on P-doped hierarchical porous carbon (SnMo–O@P-HPC). The attractive electrochemical performance of SnMo–O@P-HPC composite with an ultrahigh specific capacitance of 2121.3 F g−1 and excellent cycle stability of 92.5% over 5000 cycles is resulted from unique active component, abundant active sites, and well-organized 3D porous structure. An asymmetric supercapacitor composed of activated carbon and SnMo–O@P-HPC displays an amazing specific energy density of 114.9 W h kg−1 at 515.5 and 98.8 W h kg−1 even at 20,900 W kg−1. Importantly, it also displays a wonderful stability with excellent capacitance retention of 92.5% after 5000 cycles. The work will provide an effective and novel method to obtain the promising electrode materials for supercapacitors.