Liu Sitong, Liu Bo, Yu Meidong, Gao Hanyu, Guo Haipeng, Jiang Daguo, Yang Shenbo, Wen Yufeng, Wu Yabei
College of Mathematics and Physics, Jinggangshan University, Ji'an, Jiangxi 343009, China.
Hongzhiwei Technology (Shanghai) Co. Ltd., 1599 Xinjinqiao Road, Pudong, Shanghai, China.
Phys Chem Chem Phys. 2024 Jan 3;26(2):1376-1384. doi: 10.1039/d3cp04721k.
The rational design of high-performance anode materials is crucial for the development of rechargeable Na-ion batteries (NIBs) and K-ion batteries (KIBs). In this study, based on density functional theory (DFT) calculations, we have systematically investigated the possibility of a bilayer triazine-based covalent organic framework (bilayer TCOF) as an anode for NIBs and KIBs. The calculation of the electronic band structure shows that the bilayer TCOF is a direct band gap semiconductor with a band gap of 2.01 eV. After the adsorption of Na/K at the most favorable sites, the bilayer TCOF transitions from a semiconductor to a metal state, guaranteeing good electronic conductivity. The low diffusion barriers of the bilayer TCOF are 0.45 and 0.26 eV, respectively, indicating a fast diffusion rate of Na/K ions. In addition, the bilayer TCOF has a theoretical storage capacity of up to 628 mA h g. Finally, it is found that the average voltage of the bilayer TCOF for NIBs and KIBs is 0.53 and 0.48 V, respectively. Based on these results, we can conclude that the bilayer TCOF may be a suitable anode material for NIBs and KIBs.
高性能负极材料的合理设计对于可充电钠离子电池（NIBs）和钾离子电池（KIBs）的发展至关重要。在本研究中，基于密度泛函理论（DFT）计算，我们系统地研究了基于双层三嗪的共价有机骨架（双层TCOF）作为NIBs和KIBs负极的可能性。电子能带结构计算表明，双层TCOF是一种直接带隙半导体，带隙为2.01 eV。在最有利的位点吸附Na/K后，双层TCOF从半导体转变为金属态，保证了良好的电子导电性。双层TCOF的低扩散势垒分别为0.45和0.26 eV，表明Na/K离子的扩散速率很快。此外，双层TCOF的理论存储容量高达628 mA h g。最后，发现双层TCOF用于NIBs和KIBs的平均电压分别为0.53和0.48 V。基于这些结果，我们可以得出结论，双层TCOF可能是一种适用于NIBs和KIBs的负极材料。
