A composite of pineapple leaf-derived porous carbon integrated with ZnCo-MOF for high-performance supercapacitors.

Electrochemical energy storage heavily depends on the activity and stability of electrode materials. However, the direct use of metal-organic frameworks (MOFs) as supercapacitor electrode materials poses challenges due to their low electrical conductivity. In this study, pineapple leaf-derived biochar (PLB) was employed as a carrier for bimetallic ZnCo-MOF, resulting in the composite ZnCo-MOF@PLB-800, synthesized through growth and pyrolysis at 800 °C. The highly porous structure of PLB alleviated the aggregation of ZnCo-MOF particles, thereby enhancing the electron transfer rate and improving the conductivity of the electrode material. Electrochemical testing revealed that ZnCo-MOF@PLB-800 achieved a specific capacitance of 698.5 F g at a current density of 1 A g. The assembled asymmetric supercapacitor (ASC) demonstrated excellent specific capacitance and electrochemical stability, delivering a high energy density of 35.85 W h kg at a power density of 350 W kg, with robust cycle stability, retaining 90.4% capacitance after 8000 cycles. This work offers an effective integration of bimetallic MOFs with waste biomass-derived porous carbon for electrode materials, supporting both energy storage applications and environmental sustainability.