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The lack of safe and efficient hydrogen storage is a major bottleneck for large‐scale application of hydrogen energy. Reversible hydrogen storage of light‐weight metal hydrides with high theoretical gravimetric and volumetric hydrogen density is one ideal solution but requires extremely high operating temperature with large energy input. Herein, taking MgH2 as an example, a concept is demonstrated to achieve solar‐driven reversible hydrogen storage of metal hydrides via coupling the photothermal effect and catalytic role of Cu nanoparticles uniformly distributed on the surface of MXene nanosheets (Cu@MXene). The photothermal effect of Cu@MXene, coupled with the “heat isolator” role of MgH2 indued by its poor thermal conductivity, effectively elevates the temperature of MgH2 upon solar irradiation. The “hydrogen pump” effect of Ti and TiHx species that are in situ formed on the surface of MXene from the reduction of MgH2, on the other hand, plays a catalytic role in effectively alleviating the kinetic barrier and hence decreasing the operating temperature required for reversible hydrogen adsorption and desorption of MgH2. Based on the combination of photothermal and catalytic effect of Cu@MXene, a reversible hydrogen storage capacity of 5.9 wt% is achieved for MgH2 after 30 cycles using solar irradiation as the only energy source.

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development and manipulation of TMC cathodes with elevated plateau voltages to boost the energy densities of AIBs. More efforts should be devoted into this topic to explore novel cathodes with advantages in both specific capacity and operation voltage.The discharge voltage of intercalation type TMCs is determined by the crystal and electronic structure, elemental composition, and micro-morphology. As discussed in the previous literatures, the ionic character of the chemical bonds between transition metal cations and anions was proposed as an indicator to evaluate the electrochemical potential of cathode. [10] Following this rule, transition metal oxide, in which the highly electronegative oxygen anion would enable the chemical bonds to be more ionic, was predicted to achieve increased plateau voltage. [11] Particularly, vanadium-based oxides have shown the potentiality as high-voltage cathode materials as reported by recent studies, for which porous V 2 O 5 could deliver a relatively high working voltage of ≈0.79 V, and molybdenum-vanadium oxide exhibited a discharge plateau at ≈0.75 V. [12,13] More importantly, the tunable chemical valences of vanadium elements and facile distortion of V-O bonds in vanadium-based oxides provide the possibility to screen more suitable candidates with higher operating voltage by optimizing their crystal structures and electron distributions.Although the reported vanadium-based oxides demonstrated elevated working voltage, their reversible capacities and energy densities were unsatisfied, originating from the strong electrostatic interaction between the inserted Al 3+ and the crystal lattice, which hindered the ionic intercalation and diffusion. [14] Pre-intercalation, as an effective approach, has been successfully employed in various battery systems, especially multivalent-ion batteries, to improve the electrochemical performance of intercalation type electrode materials. [15] The guest ions could expand the interlayer space and shield the electrostatic interaction between charge carriers and the lattice, leading to an accelerated diffusion kinetics. [16,17] Besides, the pre-intercalated ions and molecules could exist as "pillar" to stabilize the framework as well as to reduce the loss of crystallinity, increasing the structural stability of active materials during cycling. [18,19] Nevertheless, the pre-intercalation strategy has not been studied in AIBs so far. It is highly desirable to acquire high-performance vanadium-based oxides for AIBs applications by the attractive pre-intercalation method.Owing to the low-cost, safety, and three-electron redox properties of aluminum, rechargeable aluminum-ion batteries (AIBs) are emerging as a promising energy storage technology. However, exploring suitable cathode material with both elevated working voltage and high reversible capacity remains a daunting challenge. Herein, under the guidance of density functional theory calculations, V 6 O 13 is proposed as a promising cathode candidate in AIBs for the first time. It is demonstrated tha...