Aluminum hydride (AlH₃) is a binary metal hydride with a mass hydrogen density of more than 10% and bulk hydrogen density of 148 $\mathrm{kg}{\mathrm{H}}_2/{\mathrm{m}}^3$. Pure aluminum hydride can easily release hydrogen when heated. Due to the high hydrogen density and low decomposition temperature, aluminum hydride has become one of the most promising hydrogen storage media for wide applications, including fuel cell, reducing agents, and rocket fuel additive. Compared with aluminum powder, AlH₃ has a higher energy density, which can significantly reduce the ignition temperature and produce H₂ fuel in the combustion process, thus reducing the relative mass of combustion products. In this paper, the research progress about the structure, synthesis, and stability of aluminum hydride in recent decades is reviewed. We also put forward the challenges for application of AlH₃ and outlook the possible opportunity for AlH₃ in the future.

The interfacial interaction between the main oxidant filler ammonium perchlorate (AP) and hydroxyl-terminated polybutadiene (HTPB) matrix in AP/HTPB propellants were studied via an all-atom molecular dynamics simulation. The results of the simulation showed the effects of the microscopic cross-linked structure of the matrix, stretching rate during uniaxial stretching, and contact area between the filler and matrix on the mechanical properties, such as the stress and strain of the composite solid propellant. Among the aforementioned factors, the stretching rate considerably affects the mechanical properties of the solid propellant, and the maximum stress of the solid propellant proportionally increases with the stretching rate. When defects were introduced on the surface of the AP filler, the contact area between the filler and matrix affected the strain type of the matrix molecules. Owing to the interaction between the molecules and atoms, the strain behaviour of the matrix molecule changed with the change in its microscopic cross-linked structure during uniaxial stretching. Molecular dynamics simulations were used to explore the characteristics at the AP–HTPB interface in AP/HTPB propellants. The aforementioned simulation results further revealed the interfacial interaction mechanism of the AP–HTPB matrix and provided a theoretical basis for the design of high-performance propellants.

As a potential anode material for lithium-ion batteries (LIBs), silicon (Si) has been widely studied because of its high capacity, appropriate potential and abundant sources. However, due to the huge volume changes of the silicon anodes during cycling, the capacity decays rapidly after a few cycles. As an important component of LIBs, polymer binders play a big role in alleviating the volume effect of silicon. The new binders developed at present could effectively improve the swelling problem of silicon, stabilize silicon anodes and improve the cycling stability of LIBs. Nevertheless, their synthesis usually involves complicated reactions. Moreover, it is a bigger challenge when a polymeric binder is used to stabilize cheap micro-silicon-particles. Herein, we present a simple process to prepare a three-dimensional polyurethane–polyacrylic acid network binder for silicon anodes by simply mixing readily available polyurethane and polyacrylic acid in water. This binder can effectively stabilize silicon anodes during cycling and improve the cycling stability of the silicon anodes. The capacity retention of the silicon anode is 70.3% after 200 cycles and 60.9% after 500 cycles, with a high specific capacity of 1934 mA h g⁻¹ after 500 cycles, showing excellent electrochemical properties.

To investigate the effects of confining pressure, strain rates, and temperatures on the mechanical properties of the Hydroxyl-terminated Polybutadiene (HTPB) propellant, uniaxial tensile tests were performed utilizing wide-temperature-confining pressure systems. The resulting damage was subsequently analyzed and characterized through scanning electron microscopy and mirco-ct. The results indicate that the stress–strain curves of HTPB at 20 and 70 °C are comparable, and the propellant damage is primarily attributed to de-wetting at 20 and 70 °C with respect to the mechanism. At −50 °C, the maximum tensile strength and ultimate tensile strain at 8 MPa surpass those at 0 and 2 MPa to a significant degree and the damage shifts from de-wetting and ductile fracture of particles to severe particle breakage with the elevated confining pressure. Ultimately, the primary curve of the HTPB propellant's maximum tensile strength was constructed by the curve fitting analysis based on the time–temperature equivalent superposition principle (TTSP) and time–pressure equivalent superposition principle (TPSP). Comparing to the properties of TPSP, TTSP exhibits a wider range of applicability and greater fitting precision in relation to the HTPB propellant. This study mainly serves to establish a fundamental theory and furnish data support for the enhancement of mechanical properties and structural integrity of solid rocket motors.

Understanding the noncovalent (weak) interactions between asphaltene molecules is crucial to further comprehending the viscosity and aggregation behavior of asphaltenes. In the past, intermolecular interactions were characterized indirectly by calculating the radial distribution function and the numerical distribution of distances/angles between atoms, which are far less intuitive than the average reduced density gradient (aRDG) method. This study selected three representative asphaltene molecules (AsphalteneO, AsphalteneT, and AsphalteneY) to investigate the relationship between viscosity and weak intermolecular interactions. Firstly, a non-equilibrium molecular dynamics (NEMD) simulation was employed to calculate the shear viscosities of these molecules and analyze their aggregation behaviors. In addition, the types of weak intermolecular interactions of asphaltene were visualized by the aRDG method. Finally, the stability of the weak intermolecular interactions was analyzed by the thermal fluctuation index (TFI). The results indicate that AsphalteneY has the highest viscosity. The aggregation behavior of AsphalteneO is mainly face–face stacking, while AsphalteneT and AsphalteneY associate mainly via offset stacking and T-shaped stacking. According to the aRDG analysis, the weak interactions between AshalteneT molecules are similar to those between AshalteneO molecules, mainly due to van der Waals interactions and steric hindrance effects. At the same time, there is a strong attraction between AsphalteneY molecules. Additionally, the results of the TFI analysis show that the weak intermolecular interactions of the three types of asphaltene molecules are relatively stable and not significantly affected by thermal motion. Our results provide a new method for better understanding asphaltene molecules’ viscosity and aggregation behavior.