Guangmin Yang

2D MA2Z4 materials are promising anode candidates for lithium-ion batteries due to their exceptional stability and mechanical strength. MoSi2N4 offers a high theoretical specific capacity, low average lithiation voltage, good electronic conductivity, and fast Li-ion diffusion. Meanwhile, 2D SiC stands out for its excellent thermal stability, chemical inertness, and high electron mobility. In this study, we rationally design a van der Waals heterojunction of SiC and MoSi2N4, with the aim of enhancing electrochemical performance. Using first-principles calculations, we systematically evaluate both two-layer and three-layer SiC/MoSi2N4 heterostructures as prospective Li-ion battery anode. The results reveal that the three-layer heterostructure exhibits a higher capacity compared to its bilayer counterpart, thereby establishing its viability as a high-performance anode material. Notably, it exhibits a significantly reduced Li-ion diffusion barrier, indicating excellent rate capability and fast charge/discharge kinetics. Moreover, molecular dynamics simulations confirm the thermodynamic stability of the heterostructure at operating temperatures, further supporting its practical feasibility. These findings offer fundamental insights for developing advanced 2D heterostructure anodes.

2D MA2Z4 materials are promising anode candidates for lithium-ion batteries due to their exceptional stability and mechanical strength. MoSi2N4 offers a high theoretical specific capacity, low average lithiation voltage, good electronic conductivity, and fast Li-ion diffusion. Meanwhile, 2D SiC stands out for its excellent thermal stability, chemical inertness, and high electron mobility. In this study, we rationally design a van der Waals heterojunction of SiC and MoSi2N4, with the aim of enhancing electrochemical performance. Using first-principles calculations, we systematically evaluate both two-layer and three-layer SiC/MoSi2N4 heterostructures as prospective Li-ion battery anode. The results reveal that the three-layer heterostructure exhibits a higher capacity compared to its bilayer counterpart, thereby establishing its viability as a high-performance anode material. Notably, it exhibits a significantly reduced Li-ion diffusion barrier, indicating excellent rate capability and fast charge/discharge kinetics. Moreover, molecular dynamics simulations confirm the thermodynamic stability of the heterostructure at operating temperatures, further supporting its practical feasibility. These findings offer fundamental insights for developing advanced 2D heterostructure anodes.

Electric double‐layer capacitors (EDLCs) are advanced electrochemical devices for energy storage and have attracted strong interest due to their outstanding properties. The energy storage properties are closely related to the electrode/electrolyte interface interaction. The microstructure of the electrode surface can make a significant impact on the EDL structure. Here, we investigated boron (B), nitrogen (N), and sulfur (S) doping in graphene electrodes coupled with ionic liquid (IL) electrolytes using molecular dynamics (MD) simulations under the constant potential method (CPM). The results show that heteroatom N‐doping elevates ionic conductivity by 15 mS/cm compared to pristine graphene, driven by weakened electrode‐solvent interactions, with the ethanol diffusivity enhanced 36%. Notably, B‐doped graphene achieves a superior double‐layer capacitance ( C _D ) of 7.75 μF/cm ² within a −1 to 2 V window, attributed to additional charge storage sites and hole carrier injection that modify the electronic structure. These results demonstrate that heteroatom doping can regulate both electronic properties and interfacial dynamics, thereby mitigating the energy‐power trade‐off. Our work advances the molecular‐level understanding of EDLCs and provides a foundation for exploring heteroatom doping strategies to design high‐performance graphene‐based supercapacitors.

First superconducting V–F compound (T_c = 0.85 K) with delocalized electrons stabilized under high pressure.

High-energy-density materials (HEDMs) can release enormous amounts of energy through redox reactions, exhibiting high stability, low sensitivity, and environmental friendliness, which are crucial for national defense and energy storage applications. Nitrogen-rich transition metal nitrides (TMNs) generally contain various polynitrogen structures, enabling them to store large amounts of energy, which could be potential HEDMs. Here, we systematically search the pressure-induced stable phases of Mo–N compounds under high pressure through first-principles swarm-intelligence structural search calculations. Several new molybdenum polynitride phases (e.g., P4/mbm MoN₂, P4/mnc MoN₈, and Immm MoN₁₀) are predicted to be stable or meta-stable under high pressure. The accurate structure of the experimental phase Mo₅N₆ is also proposed. The calculation of explosive performance shows that MoN₆, MoN₈ and MoN₁₀ have high energy densities (4.83, 2.51, and 2.93 kJ g⁻¹) and superior detonation velocity (18.25, 11.71, and 12.16 km s⁻¹) and detonation pressure (251.61, 94.69, and 100.21 GPa) properties, which are expected to become efficient HEDMs. In addition, MoN₆ also exhibits potential as a superhard material, with a Vickers hardness of 50.3 GPa. This theoretical exploratory research opens up opportunities to explore high-energy-density and superhard properties in N-rich Mo–N compounds.