Preparation of Zn-BTC with Different Morphologies of simple synthetic graphene loading and Their Supercapacitor Performance

Abstract

Abstract The remarkable advantages of supercapacitors, such as high power density, fast charge-discharge rate, and long cycle life, have attracted considerable attention. Metal-organic framework materials (MOFs) have been widely utilized in the field of energy conversion and storage due to their enormous specific surface area and tunable pore structures. However, the poor conductivity of MOFs hinders their satisfactory electrochemical performance when used as electrode materials for supercapacitors. To address this issue, a graphene-supported Zn-BTC metal-organic framework material with different morphologies was successfully synthesized using a simple ultrasonic oscillation method and a one-step solvothermal method. The synthesized one-dimensional rod-shaped Zn-BTC material was uniformly anchored on the wrinkled graphene nanosheet layer, exhibiting excellent capacitance performance with a specific capacitance of 201.3 C g-1 (at 1 A g-1), surpassing that of graphene-supported two-dimensional sheet-like Zn-BTC (152.6 C g-1), graphene-supported three-dimensional spherical Zn-BTC (139.6 C g-1), graphene (108.2 C g-1), and one-dimensional rod-shaped Zn-BTC (63.5 C g-1). By assembling symmetric supercapacitors using graphene-supported one-dimensional rod-shaped Zn-BTC, a maximum energy density of 4.55 Wh kg-1 was achieved at a power density of 104.17 W kg-1, with a specific capacitance retention of 93.26% after 2000 charge-discharge cycles at a current density of 1 A g-1.