One-pot in situ Co-assembly of binary ZIF-8/MoS2, ZIF-8/V2O5, and ternary ZIF-8/MoS2/V2O5 composite supercapacitor electrodes

Abstract

High-performance electrodes for next-generation supercapacitors require hierarchical porosity and coupled EDLC/pseudocapacitance. In this work, we have synthesized three ZIF-8-based composites: ZIF-8/MoS₂, ZIF-8/V₂O₅, and ZIF-8/MoS₂/V₂O₅, by a scalable one-pot in-situ co-assembly (OP-ISCA) method. In this architecture, the electric double-layer capacitance of ZIF-8 is combined with the pseudocapacitive functionality of MoS₂ and V₂O₅. The XRD and FTIR confirmed the integration of MoS₂ and V₂O₅ with ZIF-8. Elemental mapping, EDS, SEM, and BET reveal that the ternary composite develops a larger specific surface area and moderately connected micro/mesopores. The electrochemical measurements showed that ZIF-8/MoS₂/V₂O₅ achieved outstanding results by reaching a high gravimetric capacitance value of 1200.8 F g⁻¹ at 2 A g⁻¹, along with an energy density of 41.69 Wh kg⁻¹, with a power density of 500 W kg⁻¹. The robust cycling stability function of this composite enabled it to maintain 98.88% of its initial capacitance after 10000 cycles. The integration of multiple transition metal components with the MOF by OP-ISCA brings forth a powerful and scalable strategy for developing supercapacitor electrodes with enhanced performance.