Enhancement of the electrochemical response of a V₂O₅ integrated biochar@poly(aniline–pyrrole) hybrid composite-coated graphite electrode

The fabrication of sustainable electrode materials with high specific capacitance values is essential for designing energy-efficient supercapacitors. With this aim, herein, V₂O₅-integrated biochar@poly(aniline-pyrrole), named the BC@CCp@V₂O₅ hybrid composite, is evaluated as an electrode material. First, biochar (BC) is prepared <i>via</i> a simple hydrothermal treatment of sucrose solution. Then, conducting poly(aniline-pyrrole) (CCp) is incorporated <i>via</i> a seeded chemical oxidation method to yield BC@CCp composite particles. Finally, the BC@CCp composite is thoroughly blended with calcined V₂O₅ at a composite to V₂O₅ (w/w) ratio of 4 : 1. The morphology and surface composition of the BC@CCp@V₂O₅ hybrid composite are analyzed and confirmed <i>via</i> electron microscopy and various spectral analyses. The electrochemical properties of BC@CCp, calcined V₂O₅ and the BC@CCp@V₂O₅-coated graphite electrode are measured and compared. According to galvanostatic charge discharge (GCD) measurements, the BC@CCp@V₂O₅-coated electrode shows an exceptionally high capacitance value of 4150.6 F g^-1 at a current density of 1.0 A g^-1. The BC@CCp@V₂O₅-coated electrode also demonstrates excellent capacitance retention (134%) at 10.0 A g^-1 after 1000 charge-discharge cycles. This significant enhancement in the capacitance and stability is achieved owing to the combination of the individual components' properties and the synergistic interplay between calcined V₂O₅ and the active centers of BC@CCp. These observations represent a significant advancement in the design of sustainable BC@CCp@V₂O₅ electrode materials for application in energy-efficient supercapacitor devices.