Mg-based alloys are regarded as highly promising materials for hydrogen storage. Despite significant improvements of the properties for Mg-based alloys, challenges such as slow hydrogen absorption/desorption kinetics and high thermodynamic stability continue to limit their practical application. In this study, to assess hydrogen storage alloys with enhanced properties, incorporating both internal microstructure modulation through the preparation of amorphous/nanocrystalline structures and surface property enhancement with the addition of Cu and CNTs, the kinetic properties of activation and hydrogenation, thermodynamic properties, and dehydrogenation kinetics are tested. The results reveal a complementary interaction between the added Cu and CNTs, contributing to the superior hydrogen storage performance observed in sample 7A-2Cu-1CNTs with an amorphous/nanocrystalline structure compared to the other experimental samples. Additionally, the samples are fully activated after the initial hydrogen absorption and desorption cycle, demonstrating outstanding hydrogenation kinetics under both high and low temperature experimental conditions. Particularly noteworthy is the hydrogen absorption exceeds 1.8 wt.% within one hour at 333 K. Furthermore, the activation energy for dehydrogenation is decreased to 64.71 kJ mol^-1. This research may offer novel insights for the design of new-type Mg-based hydrogen storage alloys, which possess milder conditions for hydrogen absorption and desorption.

High density and safe storage of hydrogen are the preconditions for the large-scale application of hydrogen energy. Herein, the hydrogen storage properties of Ti_0.6Zr_0.4Cr_0.6Mn_1.4 alloys are systematically studied by introducing Y element instead of Ti element through vacuum arc melting. After the partial substitution of Y, a second phase of rare earth oxide is added in addition to the main suction hydrogen phase, C14 Laves phase. Thanks to the unique properties of rare earth elements, the partial substitution of Y can not only improve the activation properties and plateau pressure of the alloys, but also increase the effective hydrogen storage capacity of the alloys. The comprehensive properties of hydrogen storage alloys are improved by multidimensional regulation of rare earth elements. Among them, Ti_0.552Y_0.048Zr_0.4Cr_0.6Mn_1.4 has the best comprehensive performance. The alloy can absorb hydrogen without activation at room temperature and 5 MPa, with a maximum hydrogen storage capacity of 1.98 wt.%. At the same time, it reduces the stability of the hydride and the enthalpy change value, making it easier to release hydrogen. Through theoretical analysis and first-principle simulation, the results show that the substitution of Y element reduces the migration energy barrier of hydrogen and the structural stability of the system, which is conducive to hydrogen evolution. The alloy has superior durability compared to the original alloy, and the capacity retention rate was 96.79% after 100 hydrogen absorption/desorption cycles.

Aluminum hydride is a promising chemical hydrogen storage material that can achieve dehydrogenation under mild conditions as well as high hydrogen storage capacity. However, designing an efficient and cost-effective catalyst, especially a synergistic catalyst, for realizing low-temperature and high-efficiency hydrogen supply remains challenging. In this study, the heterojunction synergistic catalyst of Ti₃C₂ supported PrF₃ nanosheets considerably improved the dehydrogenation kinetics of AlH₃ at low temperatures and maintained a high hydrogen storage capacity. In the synergistic catalyst, Pr produced a synergistic coupling interaction through its unique electronic structure. The sandwich structure with close contact between the two phases enhanced the interaction between species and the synergistic effect. The initial dehydrogenation temperature of the composite is reduced to 70.2 °C, and the dehydrogenation capacity is 8.6 wt.% at 120 °C in 90 min under the kinetic test, which reached 93% of the theoretical hydrogen storage capacity. The catalyst considerably reduced the activation energy of the dehydrogenation reaction. Furthermore, the multielectron pairs on the surface of the catalyst promoted electron transfer and accelerated the reaction.

Complex hydride LiAlH₄, as a hydrogen storage material, possesses high theoretical hydrogen storage capacity (10.5 wt.%). However, highly efficient additives are urgently required to modify its thermal stability and sluggish kinetics. Some additives exhibit unique morphology-dependent characteristics. Herein, the efficient rare earth oxide nano-CeO₂ additives with different morphologies (nanoparticles, nanocubes, and nanorods) are prepared by the hydrothermal method, and the intrinsic properties are characterized. The three different morphologies of nano-CeO₂, which are different in the Ce³⁺ content and specific surface area, are added to LiAlH₄ to improve the dehydrogenation behavior. The LiAlH₄-CeO₂-nanorod composite exhibits the optimal dehydrogenation behavior, which begins to desorb hydrogen at 76.6 °C with a hydrogen capacity of 7.17 wt.%, and 3.83 wt.% hydrogen is desorbed within 30 min at 140 °C. The dehydrogenation process of the composites demonstrates that hydrogen release is facilitated by the in-situ formed CeH_2.73 and the facile transition between the oxidation states of Ce⁴⁺ and Ce³⁺. Combined with density functional theory calculations, the addition of nano-CeO₂ can weaken the Al–H bond and accelerate the decomposition of [AlH₄]⁴⁻ tetrahedron, which is consistent with the reduction of the decomposition activation energy.

High-voltage medium-nickel low-cobalt lithium layered oxide cathode materials are becoming a popular development route for high-energy lithium-ion batteries due to their relatively high capacity, low cost, and improved safety. Unfortunately, capacity fading derived from surface lithium residue, electrode-electrolyte interfacial side reactions, and bulk structure degradation severely limits large-scale commercial utilization. In this work, an ultrathin and uniform NASICON-type Li₃V₂(PO₄)₃ (LVP) nanoscale functional coating is formed in situ by utilizing residual lithium to enhance the lithium storage performance of LiNi_0.6Co_0.05Mn_0.35O₂ (NCM) cathode. The GITT and ex-situ EIS and XPS demonstrate exceptional Li⁺ diffusion and conductivity and attenuated interfacial side reactions, improving the electrode-electrolyte interface stability. The variable temperature in-situ XRD demonstrates delayed phase transition temperature to improve thermal stability. The battery in-situ XRD displays the single-phase H1-H2 reaction and weakened harmful H3 phase transition, minimizing the bulk mechanical degradation. These improvements are attributed to the removal of surface residual lithium and the formation of NASICON-type Li₃V₂(PO₄)₃ functional coatings with stable structure and high ionic and electronic conductivity. Consequently, the obtained NCM@LVP delivers a higher capacity retention rate (97.1% vs. 79.6%) after 150 cycles and a superior rate capacity (87 mAh·g^–1 vs. 58 mAh·g^–1) at a 5 C current density than the pristine NCM under a high cut-off voltage of 4.5 V. This work suggests a clever way to utilize residual lithium to form functional coatings in situ to improve the lithium storage performance of high-voltage medium-nickel low-cobalt cathode materials.

Aqueous zinc-based battery is usually plagued by serious dendrites and side reactions including Zn corrosion and water decomposition on the anode. To address the drawbacks, constructing coating layers with high conductivity and anti-catalytic effects on hydrogen evolution reaction has been considered as an efficient strategy. Herein, cheap and abundant two-dimensional (2D) conductive graphite (KS-6) coating layer with high electronic conductivity (~ 10⁶ S·m⁻¹) could directly form strong bonding with Zn foil due to high zincophilicity, which correspondingly protects Zn metal from liquid electrolyte to inhibit parasitic hydrogen evolution and guide uniform Zn electrodeposition during cycling. The KS-6 layer owns a profitable charge redistribution effect to endow Zn anode with a lower nucleation energy barrier and a more uniformly distributed electric field compared with bare Zn. Therefore, such integrated Zn anode exhibits low voltage hysteresis (~ 38 mV) and excellent cycling stability with dendrite-free behaviors (1 mA·cm⁻² and 2 mAh·cm⁻²) over 2,000 h, far outperforming many reported Zn metal anodes in aqueous systems. Encouragingly, in light of the superior Zn@KS-6 anode, VNO_x powders and Prussian blue analogs Mn₂Fe(CN)₆ are applied as the cathode materials to assemble full batteries, which show remarkable cycling stabilities and high Coulombic efficiencies (CEs) over 200 cycles with capacity retention of 81.5% for VNO_x//Zn@KS-6 battery and over 400 cycles with capacity retention of 94.6% for Mn₂Fe(CN)₆//Zn@KS-6 battery, respectively.