钛取代水磷铁锂（LiFeSO₄F）作为锂离子电池的阴极材料：第一性原理计算与实验研究

Titanium-Substituted Tavorite LiFeSO F as Cathode Material for Lithium Ion Batteries: First-Principles Calculations and Experimental Study.

作者信息

Guo Zhendong, Wang Dashuai, Zhang Lijie, Fu Qiang, Wei Yingjin

机构信息

College of Science, Northeast Electric Power University, 132012, Jilin, P. R China.

Key Laboratory of Physics and Technology for Advance Batteries (Ministry of Education) College of Physics, Jilin University, 130012, Changchun, P. R China.

出版信息

Chempluschem. 2020 May;85(5):900-905. doi: 10.1002/cplu.202000301.

DOI:10.1002/cplu.202000301

PMID:32391632

Abstract

Titanium-substituted LiTi Fe SO F (x=0, 0.01, 0.02, 0.03) cathode materials were synthesized by a solvothermal method. X-ray diffraction, X-ray photoelectron spectroscopy, and Mössbauer spectroscopy were used to investigate the effects of Ti substitution on the structure of LiFeSO F, and it was shown that Ti substitutes the Fe(2) site. First-principles calculations and UV-visible spectroscopy demonstrate that Ti substitution reduces the bandgap of LiFeSO F which improves the electronic conductivity from 8.3×10 S cm to 3.9×10 S cm . CI-NEB and BV calculations show that the Li diffusion energy barriers along the (100), (010) and (101) directions are decreased after Ti substitution, and the Li diffusion coefficient is increased from 4.99×10 cm S to 1.59×10 cm S . The improved electronic conductivity and ionic diffusivity mean that the Ti-substituted material shows improved electrochemical properties compared to the pristine LiFeSO F.

摘要

采用溶剂热法合成了钛取代的LiTiFeSOF（x = 0、0.01、0.02、0.03）阴极材料。利用X射线衍射、X射线光电子能谱和穆斯堡尔谱研究了Ti取代对LiFeSOF结构的影响，结果表明Ti取代了Fe(2)位点。第一性原理计算和紫外可见光谱表明，Ti取代降低了LiFeSOF的带隙，使电子电导率从8.3×10 S cm提高到3.9×10 S cm。CI-NEB和BV计算表明，Ti取代后沿(100)、(010)和(101)方向的Li扩散能垒降低，Li扩散系数从4.99×10 cm S提高到1.59×10 cm S。电子电导率和离子扩散率的提高意味着与原始LiFeSOF相比，Ti取代材料的电化学性能得到了改善。