Three-dimensional porous Gd-POM/RGO composites for high-performance supercapacitor electrodes

Abstract

Herein, Gd-POM/RGO composites were prepared by embedding three-dimensional gadolinium-based polyoxometalates (Gd-POMs) in reduced graphene oxide (RGO) using a facile hydrothermal method. The novel Gd-POM/RGO composites combine the advantages of Gd-POMs and RGO, including improved specific surface area, exceptional electrical conductivity, and fast redox reactions. Moreover, the layered RGO substrates guarantee the uniform distribution of Gd-POM particles, which not only avoids agglomeration and dissolution of Gd-POMs, but also facilitates electron/ion transport. Furthermore, the Gd-POM/RGO composites deliver an enhanced capacitance of 592.8 F g⁻¹ at 0.5 A g⁻¹ and a capacitance retention of 96.8% after 5000 cycles. The constructed asymmetric supercapacitor cell, i.e. Gd-POM/RGO//AC, exhibits a maximum energy density of 36.04 W h kg⁻¹ at a power density of 752.65 W kg⁻¹ along with an ideal durability of 94.1% over 5000 cycles. This study highlights the prospects of POM-based composites as multifunctional materials for future energy storage devices.