Bimetallic zeolitic imidazolate frameworks for symmetric electrical double-layer supercapacitors with aqueous electrolytes

We have investigated a facile synthesis of nanoporous carbon using a bimetallic (Co²⁺ and Zn²⁺) zeolitic imidazolate framework (ZIF) as a precursor. The properties of the as-prepared bimetallic ZIF-derived carbon, including the specific surface area, porosity, and degree of graphitization, are precisely controlled. This material has been directly applied in a symmetric electrical double-layer supercapacitor (EDLC). The specific capacitance of the symmetric EDLC is estimated to be 10.5 F·g⁻¹ at a high current density of 10 A·g⁻¹ in 0.5 M sulfuric acid.