Nowadays, scientists are increasingly focused on finding new efficient 2D materials for hydrogen storage due to their large specific surface area, exceptional physisorption properties, and high gravimetric capacity. In this respect, we have analyzed the potential of new 2D orthorhombic (o)-B₂CN and o-B₂C₂ materials as lightweight solid mediums for hydrogen storage, employing lithium decoration through density functional theory (DFT) calculations. Both materials were found to be conductive and demonstrated excellent mechanical, dynamical and thermal stability. The binding energies of lithium adatoms to the monolayers during the decoration process were found to be −3.38 and −3.72 eV for o-B₂CN and o-B₂C₂, respectively. These values indicate strong interactions with both substrates and the lack of lithium clustering given that they are higher than its cohesive energy (−1.63 eV). The lithium decoration technique significantly improves the adsorption of H₂ molecules on both materials, where each system adsorbs 32 molecules with an average adsorption energy of 0.25 and 0.23 eV for 32H₂@8Li-B₂CN and 32H₂@8Li-B₂C₂, respectively, along with excellent gravimetric capacities of 12.87 and 13.29 wt% and desorption temperatures of 186 and 171 K. To assess dynamical stability, AIMD calculations were conducted on fully loaded H₂ systems at temperatures of 100, 200, 400 and 500 K, demonstrating complete H₂ desorption and confirming the reversibility of both systems. A radial distribution function (RDF) analysis was conducted to examine the thermal effects on Li–H atomic correlations and assess the stability of hydrogen adsorption at different temperatures. Based on these results, it can be concluded that Li-decorated o-B₂CN and o-B₂C₂ show considerable potential for hydrogen storage applications.

The development of novel anode materials with superior electrochemical performance is imperative for advancing next-generation high-performance rechargeable batteries beyond current limitations. In this study, it presents a 2D o-Al₂C₂ monolayer as a promising lightweight candidate for lithium and sodium–ion battery systems, based on the density functional theory investigations and ab initio molecular dynamics (AIMD) simulations. Our comprehensive investigation demonstrates that the o-Al₂C₂ monolayer exhibits remarkable stability with a cohesive energy of −5.30 eV atom⁻¹ and maintains its structural integrity at room temperature during extended AIMD simulations. The o-Al₂C₂ monolayer demonstrates exceptional electrochemical characteristics for Li and Na storage: theoretical specific capacities of 3780.42 and 3436.75 mA h g⁻¹, optimal average open circuit voltages of 0.81 and 0.67 V, and favorable diffusion barriers of 0.62 eV and 0.31 eV, respectively. These performance metrics significantly surpass those of conventional graphite (372 mA h g⁻¹) and other recently reported 2D anode materials, establishing o-Al₂C₂ as an exceptionally promising candidate for next-generation energy storage applications. Hence, this current theoretical investigation suggests that the o-Al₂C₂ monolayer holds significant potential for future experimental studies in lithium and sodium storage applications for LIB and NIB systems.