Molecule-Level Hybridization of MXene-Azo Molecule for Enhanced Electrode Affinity and Photorechargeable Supercapacitor Performance

The interaction between the electrode and electrolyte is a critical determinant of the charge storage rate in photorechargeable supercapacitors. Enhancing the electrode’s affinity for the electrolyte is commonly achieved by modifying the electrode surface with polar functional groups and increasing its porosity. However, finely tailored methods specific to particular electrodes remain underdeveloped. In this study, based on DFT calculations, we propose the hybridization of MXene with 4-aminoazobenzene-4′-sulfonic acid sodium to enhance the interfacial affinity between the electrode and electrolyte. Our findings reveal that the −SO3 group facilitates electron transfer from MXene to azo molecules, reducing the desolvation energy of Li+ in electrolytes and thereby increasing wettability. Consequently, the hybrid electrode exhibits an impressive area-specific capacity of 2837.5 mF/cm2. Furthermore, the prepared flexible supercapacitor demonstrates high energy density, retains nearly 100% of its capacitance after 20,000 charge–discharge cycles, and maintains 90% capacitance retention after 5000 bending cycles. When integrated with tandem perovskite solar cells, the photorechargeable supercapacitor effectively stores photogenerated charges, achieving an overall conversion efficiency of 19.4%. These findings underscore the exceptional electrochemical performance of the developed hybrid electrode and its potential for a wide range of energy storage applications.