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The hydrogen storage potential and cost-effectiveness of MgH2have rendered it a desirable material for hydrogen storage. However, its application has been hindered by limitations in thermal stability and dehydrogenation kinetics. In this study, the carbon nanotube-Pd bifunctional catalyst was prepared by using hydrothermal and calcination technology, significantly improving the kinetics of Mg/MgH2during hydrogen adsorption/desorption. The activation energy for the Mg@ CNTs-Pd was reduced to 42.73 kJ/mol, as determined by fitting the Avrami–Erofeev model with the Arrhenius equation. Additionally, the activation energy during dehydrogenation was found to be 73.98 kJ/mol based on the Johnson–Mehl–Avrami–Kolmogorov equation and the Arrhenius equation. It is worth noting that the dynamic enhancement persists even after 10 cycles. This groundbreaking research has paved the way for potential applications of MgH2as a hydrogen storage material, providing it with broader development opportunities.

Nanostructured birnessite-type δ-MnO2(KMO-V) with intercalated K+and oxygen vacancies is synthesized by a hydrothermal method at 160 °C followed by annealing under 300 °C in Ar atmosphere with non-toxic and inexpensive γ-MnO2(Unit price: 0.96–1.6 US$ Kg−1) as raw material. The interplanar spacing in (001) diffraction direction of KMO-V is near 0.719 nm. The considerable initial discharge potential of about 1.8 V, specific energy of 389.88 Wh kg−1, and cyclic stability of 91.9% after 1500 cycles at 1.0 A g−1of KMO-V are obtained. A hybrid intercalation mechanism of H+and Zn2+is revealed, KMO-V has the best diffusion kinetics performance of Zn2+among the samples according to the calculation based on density functional theory (DFT). The by-product Zn4(OH)6SO4·4H2O and Mn2+are thought to be the primary factors of capacity decay, the synergy of K+pre-intercalation and oxygen vacancies plays a critical role of enhancing structural stability and reaction kinetics in KMO-V. Thus, this work provides an eco-friendly research method of inexpensive electrode material in aqueous Zn-ion batteries (AZIBs) for large-scale energy storage.