Abstract Carbon nanotubes (CNTs) are a candidate electrode material for lithium-ion batteries (LIBs). Tailoring CNTs to shorter tubes with open ends can enhance the lithium capacity. Recently, the carbon nanobelt (CNB) has been successfully synthesized. This work concentrates on ab initio modelling of lithium adsorption on short open-ended CNTs with different lengths based on density functional theory (DFT). Li atoms adsorbed on CNB (one-segment (6,6) CNT) and short (6,6) CNTs with 2–12 segments as well as periodical CNTs were modelled. The most stable Li-CNT configurations were obtained after the total system energies were minimized. Lithium adsorption energies of short CNTs were found to have a regular oscillatory dependence on the number of segments along tube axis. Energetics for lithium moving across the tube wall and along the tube axis were also calculated for open-ended CNTs. Ab initio molecular dynamics (ABMD) was performed to simulate the lithium diffusion behaviors in short CNTs. Among all short CNTs, the CNT with 2 segments was the most promising electrode material for LIBs and its lithium capacity was finally predicted.

中文翻译：

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考虑管长影响的锂吸附在短碳纳米管上的从头算研究

摘要 碳纳米管（CNTs）是锂离子电池（LIBs）的候选电极材料。将 CNT 剪裁成具有开口端的较短管可以提高锂容量。最近，碳纳米带（CNB）已被成功合成。这项工作的重点是基于密度泛函理论 (DFT) 对不同长度的短开口碳纳米管上的锂吸附进行从头算建模。对吸附在 CNB（单段 (6,6) CNT）和具有 2-12 段的短 (6,6) CNT 以及周期性 CNT 上的锂原子进行建模。在系统总能量最小化后，获得了最稳定的 Li-CNT 结构。发现短碳纳米管的锂吸附能对沿管轴的段数具有规律的振荡依赖性。还计算了开放端 CNT 的锂穿过管壁和沿管轴移动的能量。进行从头算分子动力学（ABMD）来模拟短碳纳米管中的锂扩散行为。在所有短碳纳米管中，2段碳纳米管是最有前途的锂离子电池电极材料，其锂容量最终被预测。