Investigation into Enhanced Electrochemical Hydrogen Storage Performance of Co0.9Cu0.1Si Alloy via Cobalt-Nitrogen Co-Doped Reduced Graphene Oxide Coating

Co 0.9 Cu 0.1 Si alloy was synthesized by mechanical alloying. Nitrogen-doped reduced graphene oxide (N-rGO), cobalt-doped reduced graphene oxide (Co-rGO), and cobalt-nitrogen co-doped reduced graphene oxide (Co-N-rGO) were successfully synthesized via a hydrothermal method and subsequently coated with alloy nanoparticles, to enhance the electrochemical hydrogen storage capabilities of composite materials. In comparison to the pristine alloy, the composite material exhibits superior discharge specific capacity, cycling stability, and kinetic performance. The Co-N@rGO coated sample demonstrates superior electrochemical performance compared to all other coated rGO composites. The results indicate that the optimal addition ratio of Co-N@rGO is 5 wt.%. At this ratio, the battery achieves a maximum discharge capacity of 603.3 mAh/g. After 50 cycles, the capacity retention rate is 64.6% of the initial maximum discharge capacity. The significant enhancement in the electrochemical energy storage performance of the composite materials can be primarily attributed to the synergistic effects of nitrogen doping, cobalt doping, and the intrinsic properties of reduced graphene oxide (rGO). rGO enhanced the electrical conductivity of the composite material, thereby improving the efficiency of charge transfer during electrochemical reactions. Nitrogen doping improved the wettability of the rGO surface with the electrolyte and generated numerous active sites for hydrogen adsorption, significantly enhancing the electrocatalytic performance of rGO. Cobalt deposition on rGO further increased the electrical conductivity of the composite, promoted hydrogen atom adsorption, and accelerated hydrogen diffusion. The integration of rGO with nitrogen doping and cobalt incorporation demonstrated a strong synergistic effect, significantly further enhancing the kinetic characteristics of the electrochemical reactions.