Abstract
The development of multifunctional materials is vital for next-generation sustainable energy technologies. Here, we report a bifunctional Cu(2) (-) (x) Te@rGO nanocomposite synthesized via a one-pot hydrothermal method, where copper-deficient telluride (Cu(2) (-) (x) Te) nanoparticles are uniformly anchored on reduced graphene oxide (rGO) sheets. The composite exhibits enhanced Li-ion storage performance, delivering a capacity of 554 mAh g(-1), outperforming pristine Cu(2) (-) (x) Te (349 mAh g(-1)), owing to the synergistic interaction between the hierarchical Cu(2) (-) (x) Te nanoparticles and rGO. Detailed electrochemical characterization including the galvanostatic intermittent titration technique and cyclic voltammetry is invoked to elucidate the Li-ion storage mechanism including the Li-ion diffusion coefficient and kinetics. Further, the high-power Cu(2-x) Te@rGO//activated carbon Li-ion capacitor fabricated exhibits good electrochemical performances with 88% capacity retention after 10,000 cycles. Additionally, the nanocomposite shows efficient OER activity with a low overpotential of 440 mV at 100 mA cm(-2) and a Tafel slope of 86 mV dec(-1). The integration of Li-ion capacitive performance with water splitting capability highlights the potential of Cu(2) (-) (x) Te@rGO nanocomposites as a promising bifunctional material for advanced energy systems.