发表机构
Indian Institute of Technology (Indian School of Mines); Bhabha Atomic Research Centre（印度理工学院（印度矿业学院）; 巴哈原子研究中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过第一性原理计算证实，二维Cu₈B₁₄是高性能锂离子电池负极候选材料，其线缺陷可进一步降低Li迁移势垒、提升扩散系数。
AI 中文摘要
本研究采用第一性原理计算，探究二维硼化铜Cu₈B₁₄作为锂离子电池负极材料的可能性。研究发现，该单层结构即使在高温下仍能保持结构完整性，电子计算证实了原始及载锂体系均具有金属特性。对Cu₈B₁₄进行系统锂化时，获得了430mAhg⁻¹的比容量；最有利路径的Li扩散势垒为0.32eV，扩散系数约为2.26×10⁻⁵cm²s⁻¹；开路电压为0.53V，处于0.1-1.0V的最优负极范围内。这些综合特性表明Cu₈B₁₄是先进电池负极的极具吸引力的候选材料。此外，为理解缺陷及其对不同参数的影响，研究人员探究了实验中已确定的硼化铜线缺陷构型。该线缺陷单层保留了约385mAhg⁻¹的理论容量，引入的线缺陷进一步将Li迁移势垒降低至0.21eV，使宏观扩散系数提升至约5.6×10⁻⁴cm²s⁻¹，证实结构缺陷可加速该材料中的锂离子传输动力学。
英文摘要
In this work, we combine first-principles calculations, ab initio molecular dynamics (AIMD), and machine-learning-interatomic-potential molecular dynamics (MLIP-MD) to investigate lithium storage and transport in two-dimensional Cu$_8$B$_{14}$, including an experimentally identified line-defect configuration. Pristine Cu$_8$B$_{14}$ remains metallic upon lithiation and exhibits favourable Li adsorption, a single-surface theoretical capacity of 427~mAh~g$^{-1}$, and an average open-circuit voltage of approximately 0.53~V. The lowest Li migration barrier on the pristine surface is 0.32~eV. The line-defected structure retains a capacity of approximately 400~mAh~g$^{-1}$ while reducing the local migration barrier to 0.21~eV. To access Li dynamics beyond the picosecond time scale of AIMD, a pretrained MACE-MP-0 model was fine-tuned against system-specific DFT energies and forces and employed in nanosecond-scale simulations from 400 to 600~K. Both pristine and line-defected lithiated monolayers remain structurally stable over this temperature range. At 400~K, the line-defected system exhibits a higher in-plane Li tracer diffusivity ($3.97\times10^{-5}$~cm$^{2}$~s$^{-1}$) than the pristine monolayer ($2.50\times10^{-5}$~cm$^{2}$~s$^{-1}$), whereas the pristine system becomes more diffusive at 500 and 600~K. Arrhenius analysis yields effective activation energies of 0.147 and 0.225~eV for the line-defected and pristine systems, respectively. These results show that the line defect modifies the Li-transport landscape and its temperature dependence rather than uniformly enhancing long-range diffusion, while preserving competitive Li-storage capacity and structural stability.
Comments13 pages, 16 figures, 5 tables
