Zhu Zixuan, Song Dongxing
Queen Mary University of London Engineering School, Northwestern Polytechnical University, Xi'an, Shanxxi 710072, China.
Key Laboratory of Process Heat Transfer and Energy Saving of Henan Province, School of Mechanics and Safety Engineering, Zhengzhou University, Zhengzhou, Henan 450001, China.
ACS Omega. 2023 Feb 21;8(9):8441-8447. doi: 10.1021/acsomega.2c07472. eCollection 2023 Mar 7.
Stacked two-dimensional (2D) materials as bulk materials are more practical to be anodes of Li-ion batteries than their monolayers due to the easier operation, while the ion kinetics and capacity are usually deteriorated by the geometric constraint in stacked structures. Herein, we perform first-principles calculations to explore anode performances of the stacked graphdiyne (GDY) where the functional group is intercalated to enlarge the interlayer distance. Compared to the monolayer GDY, which has a diffusion barrier of only 0.315 eV and capacity as high as LiC, the pristine stacked GDY presents lower capacity (LiC) and higher diffusion barrier (0.638-0.922 eV) due to the geometric constraint, while after functionalization, the stacked GDY exhibits excellent properties for storing ions similar to the monolayer GDY. A good electronic conductivity is also confirmed by the density of states. Our study indicates that functionalization is an effective pathway to improve the anode performances of stacked 2D materials by optimizing the interlayer structure.
与单层材料相比，堆叠二维（2D）材料作为 bulk 材料用作锂离子电池的阳极更具实用性，因为其操作更简便，然而离子动力学和容量通常会因堆叠结构中的几何约束而恶化。在此，我们进行第一性原理计算，以探索在堆叠石墨炔（GDY）中插入官能团以扩大层间距时的阳极性能。与单层 GDY 相比，单层 GDY 的扩散势垒仅为 0.315 eV 且容量高达 LiC，由于几何约束，原始堆叠 GDY 的容量较低（LiC）且扩散势垒较高（0.638 - 0.922 eV），而官能化后，堆叠 GDY 表现出与单层 GDY 相似的优异离子存储性能。态密度也证实了其良好的电子导电性。我们的研究表明，官能化是通过优化层间结构来提高堆叠二维材料阳极性能的有效途径。
