Pine fruit activated carbon modified with CuCo2Se4 for the application in high-performance battery-type supercapacitor

Biomass has attracted considerable interest in the field of energy storage because of its outstanding characteristics, such as superior charge transport ability, affordability, eco-friendly, structural versatility, and renewability. Moreover, biomass-derived activated carbons, combined with pseudocapacitive materials, have recently gained popularity as efficient electrochemical components for energy storage devices. In this study, activated carbon was prepared from pinecone flowers as the biomass precursor through a process involving alkaline treatment and pyrolytic carbonization in an inert gas environment. Subsequently, CuCo₂Se₄ nanoparticles (CCS) were synthesized on the Pine Fruit Activated Carbon (PFAC) surface via a hydrothermal method. CCS serves as a pseudocapacitive material to compensate for the volumetric and gravimetric performance limitations of carbon. The resulting PFAC@CCS composite provides efficient pathways for electrolyte ion diffusion and rapid electron transfer when employed as electrode materials. This nanocomposite was evaluated as a potential electrode for supercapacitors. The prepared electrode, leveraging its unique characteristics, exhibits a significantly enhanced specific capacity of 639.55 F g^-1 at a current density of 1 A g^-1, demonstrating excellent rate capability and commendable cycling stability. Furthermore, a hybrid supercapacitor was constructed using PFAC@CCS as the positive electrode and PFAC as the negative electrode. This device demonstrates exceptional energy storage performance, delivering an energy density of 65.41 Wh kg^-1 while operating at a power output of 16.53 W kg^-1, with only a minimal 4.5% decline in capacity following 5000 continuous charge-discharge cycles at 25 °C temperature.