共价有机骨架/碳纳米管复合材料中锂离子吸附与传输特性的分子模拟

利用分子模拟方法对共价有机骨架 (covalent organic framework, COF)/碳纳米管(carbon nanotube, CNT) 复合材料 COF@CNT 中锂离子 (Li$^{+})$ 的吸附与传输特性开展研究, 明确了 Li$^{+}$ 的吸附位点与吸附顺序, 得到了相应的吸附能, 并观察 COF@CNT 的表观形貌变化. 当达到饱和吸附状态时, COF@CNT 的体积变化率仅为 0.25, 平均电压保持在 2.00 V 以上, 而理论容量则高达 1 402.47 mAh/g. 此外, Li$^{+}$ 在 COF@CNT 内部的电导率大于其在单纯 CNT 中电导率的实测值. 模拟结果可为此类体系的实际应用提供理论基础.

Adsorption and transport properties of the lithium ion in a covalent organic framework/carbon nanotube composite by molecular simulation

In this study, the adsorption and transport properties of the lithium ion (Li$^{+})$ in a covalent organic framework/carbon nanotube composite (COF@CNT) are investigated through molecular simulation. The adsorption sites and sequence of Li$^{+}$ are defined and the corresponding adsorption energy is obtained. In addition, apparent change in the morphology of the COF@CNT is identified. When saturated adsorption is reached, the volumetric change rate of the COF@CNT is only 0.25. Simultaneously, the average voltage is maintained at greater than 2.00 V, and the theoretical capacity reaches as high as1402.47 mAh/g. Finally, the electronic conductivity of Li$^{+}$ inside the COF@CNT exceeds that in a pure CNT. The results of this study can provide a theoretical basis for the practical application of these systems.