High performance all-solid-state symmetric supercapacitor based on porous carbon made from a metal-organic framework compound

In this work, we demonstrate the synthesis of porous carbon material with high specific surface area by using metal-organic framework (MOF) as precursor. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) have confirmed that the material was amorphous and consisted of nanoparticles (5–6 nm) and hierarchical distribution of pores. The characterization of the material by N₂ adsorption/desorption isotherm measurement have shown that the material had a high specific surface area reaching to 2618.7 m² g⁻¹ and abundant porosity with pore size less than 10 nm. The investigation of the electrochemical properties of the material has shown the porous carbon electrode possessed excellent rate performance with high specific capacitances of 150.8 F g⁻¹ at a current density of 5 A g⁻¹, and 133.6 F g⁻¹ at a current density of 50 A g⁻¹, respectively. An all-solid-state symmetric supercapacitor assembled using the as-prepared porous carbon as electrodes and Na₂SO₄/PVA gel as an electrolyte delivered a high power density of 13 516.4 W kg⁻¹ with an energy density of 8.26 Wh kg⁻¹. A high energy density of 17.37 Wh kg⁻¹ was obtained at discharge current density of 1 A g⁻¹. In addition, the device exhibited superior cycling performance with 94.8% retention rate after 10 000 cycles at a current density of 10 A g⁻¹.