Enhanced electrochemical hydrogen storage performance of Co0.9Cu0.1Si alloy achieved through the synergistic effects of PANI, NiO NPs, and GO

[Display omitted] •PANI, NiO NPs and GO are incorporated into the alloy to form a composite.•Cycle stability, Cmax and kinetic properties of composite materials are enhanced.•The synergistic effect of PANI, NiO NPs and GO enhances the kinetic performance. Mechanical alloying is used to prepare Co0.9Cu0.1Si hydrogen storage alloy. Coral-like polyaniline (PANI) and NiO nanoparticles (NiO NPs) are synthesized separately. In order to improve the electrochemical properties of the alloy, polyaniline, NiO NPs and graphene oxide (GO) are doped into the alloy via mechanical alloying to form a composite. The composite material doped with PANI, NiO NPs and GO ultimately demonstrates superior discharge capability compared to the pristine alloy, establishing it as the most high-performing among all samples. The sample doped with both PANI or NiO NPs and GO exhibited superior discharge capacity and HRD performance compared to the sample containing only GO. The Co0.9Cu0.1Si + PANI/NiO NPs/GO electrode not only demonstrates a remarkable maximum discharge capacity of 590.82 mAh/g, but it also boasts an impressive highest exchange current density of 180.5 mA/g, alongside a notable cycle stability of 61.1 %. The enhancement of electrochemical activity and kinetic performance in alloys is attributed to the synergistic effect exerted by PANI, NiO NPs and GO. GO itself has a high specific surface area and good conductivity, which is conducive to the transfer of hydrogen inside the alloy and enhance the hydrogen storage performance of the alloy. Polyaniline participate in the reversible redox reaction and remain stable during the charge/discharge cycle, which promoted the surface anodizing process of the alloy. The NiO NPs catalyst can effectively weaken the OH bond, facilitating the dissociation of adsorbed water. These factors work together to significantly improve the overall electrochemical hydrogen storage performance of the alloy.