AI 中文总结
本文通过第一性原理研究AlF3在石墨中的吸附与插层，揭示了其诱导的协同吸附与扩散捕获机制，为调控碳基储能系统插层效率提供了定量框架。
AI 中文摘要
石墨作为碳基电极材料，其结构与电子对分子插层的响应是决定其性能的核心，但亚表面插层与表面吸附之间的微观耦合机制仍未被充分理解。本文通过第一性原理研究AlF3在石墨中的吸附与插层行为，以解释近期观测到的两步自限吸附机制的微观起源。采用密度泛函理论（DFT-D3）计算表明，单个插层的AlF3分子通过类泡状表面变形，局部改变石墨的结构、电子性质与扩散行为。对比原始石墨与含亚表面插层分子的石墨表面，覆盖度依赖的吸附能量学显示，在类泡结构上方，横向相互作用从排斥转变为协同结合，该转变由局部曲率与插层诱导的电荷重新分布驱动。扩散势垒计算表明，类泡同时作为动力学陷阱，提高了扩散势垒，使表面迁移从准无势垒状态转变为热激活 regime。电荷密度差与Mulliken布居分析表明，插层剂作为稳定的电子库，加深了表面势能面，动力学上固定了吸附物种。综上，这些结果建立了石墨中插层诱导变形的结构-性质关系，为调控碳基储能与转化系统的插层效率提供了定量框架。
英文摘要
Graphite's structural and electronic response to molecular intercalation is central to its performance as a carbon-based electrode material, yet the microscopic coupling between subsurface intercalation and surface adsorption remains poorly understood. We present a first-principles investigation of AlF3 adsorption and intercalation in graphite to explain the microscopic origin of a recently observed two-step self-limiting sorption mechanism. Using density functional theory (DFT-D3), we show that a single intercalated AlF3 molecule locally transforms the structure, electronic properties, and diffusion behavior of graphite through a blister-like surface deformation. Comparing pristine graphite with a graphite surface containing a subsurface intercalated molecule, coverage-dependent adsorption energetics reveal a crossover from repulsive lateral interactions to cooperative binding above the blister, driven by local curvature and intercalation-induced charge redistribution. Diffusion-barrier calculations show that the blister simultaneously acts as a kinetic trap, raising diffusion barriers and transitioning surface mobility from a quasi-barrierless to a thermally activated regime. Charge-density difference and Mulliken population analyses identify the intercalant as a stable electronic reservoir that deepens the surface potential landscape, kinetically immobilizing adsorbed species. Together, these results establish a structure-property relationship for intercalation-induced deformation in graphite, offering a quantitative framework for controlling intercalation efficiency in carbon-based energy storage and conversion systems.
Comments14 pages, 7 Figures and SI
