Activated carbon induced synergistic effect of bismuth metal-organic framework-based zero and one-dimensional heterostructure for efficient supercapacitor

The rapid degradation of battery-like metal organic frameworks (MOFs) electrodes due to inhomogeneous electrochemical reactions and volume expansion in heterostructured MOF electrodes limits their application in energy storage devices. This study introduces a straightforward approach to enhance the electrochemical performance of Bi-MOFs (BMs) by incorporating low-cost activated carbon (AC) through a solvothermal compositing method, resulting in 0D nanoparticle-1D nanorod heterostructures. The developed BM/AC heterostructures (denoted as BM-2) provide a continuous electron pathway, facilitating improved ion mobility and promoting homogeneous electrochemical reactions. As a result, BM-2 demonstrates a remarkable specific capacity of 387.6C g−1 at a current density of 5 mA cm−2. Furthermore, an asymmetric supercapacitor (ASC) device of BM-2//AC was assembled, which achieved an energy density of 62.4 Wh kg−1 at a power density of 4332 W kg−1, with a retention of 70.09% capacity over 5000 cycles, underscoring its remarkable cyclic stability. This work highlights the cost-effective direct integration of AC into the solvothermal synthesis of BMs, forming an in-built 3D interconnected network that significantly enhances electrode performance, paving the way for high-performance hybrid supercapacitors.