Fabrication of amorphous Co/Mo–MnSex electrode materials for high-performance hybrid supercapacitors

Abstract

The fabrication of polymetallic selenide nanomaterials as supercapacitor electrode materials via a convenient and efficient design route has become the center of attention in energy storage research. However, the design and synthesis of such materials still does not address the major challenges of optimal energy storage. Herein, we present the synthesis of high-performance selenated polymetallic amorphous Co/Mo–MnSe_x supercapacitor electrodes with metal MOFs as precursors. The morphology and capacitance of the electrodes are improved by changing the structure of Co/Mo–MOF through ion doping and hydrothermal selenization. At a current density of 1 A g⁻¹, the Co/Mo–MnSe_x electrode material exhibits an ultrahigh specific capacitance of 3679 F g⁻¹. In particular, the combined hybrid supercapacitor (HBS) has an excellent energy density of 141.3 W h kg⁻¹ at a power density of 496 W kg⁻¹ and even 79.7 W h kg⁻¹ at a power density of 15 105.3 W kg⁻¹. It can light up light strips 0.5 and 1.0 m in length. In addition, the superb cycling stability of the electrode material can be corroborated by its retention rate of 96.0% after 35 000 cycles. This work synthesized excellent supercapacitor electrode materials through a facile and novel method and provides insights into the design of MOF-based polymetallic materials.