The phosphorous-doped 2D nanosheet assembled 3D Mn2V2O7 microflowers on Ni foam as a binder-free electrode for high energy density asymmetric supercapacitor application

Abstract

In recent times, transition-metal oxides have been recognized as highly promising candidates for supercapacitor applications. Nevertheless, their progress in diverse fields has been hindered by challenges such as poor electrical conductivity and a shortage of active reaction centers. Doping heteroatoms would overcome these drawbacks and enhance the supercapacitor properties in transition metal oxides. Herein, the phosphorous-doped 2D nanosheet assembled 3D Mn2V2O7 micro flowers were grown on the Nickel foam using the hydrothermal method and successively phosphatized in a tube furnace, which was utilized as a binder-free supercapacitor electrode. The synthesis process involved varying the concentration of phosphorus (P), resulting in the successful formation of uniform P-decorated Mn2V2O7 microflowers. The unique microflower structure and doping P into the Mn2V2O7 material enhance the electrochemical properties with a specific capacity of 850C g？1 (1545 F g？1) at 1 A g？1 in a three-electrode cell. Moreover, the assembled Mn2V2O7？600/NF//AC device delivers a specific capacity of 258C g？1 (211 F g？1) at 1 A g？1 with a remarkable rate of 47 % at a high current density of 20 Ag ？1. The device achieved a maximum energy density of 43.2 Wh kg？1 at a power density of 604.7 W kg？1, and it maintained 91 % of initial capacity after 10,000 charge/discharge cycles at 20 A g？1. These results suggest that the P-doping 2D nanosheet assembled 3D Mn2V2O7 could be promising electrode materials for supercapacitor applications.