First-principles investigation of the electronic and Li-ion diffusion properties of LiFePO{sub 4} by sulfur surface modification

Journal Article · Thu Aug 14 00:00:00 EDT 2014 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4892018· OSTI ID:22314599

Xu, Guigui ^[1]; Zhong, Kehua; Zhang, Jian-Min; Huang, Zhigao ^[2]

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1. Concord University College Fujian Normal University, Fuzhou 350117 (China)
2. College of Physics and Energy, Fujian Normal University, Fuzhou 350117 (China)

We present a first-principles calculation for the electronic and Li-ion diffusion properties of the LiFePO{sub 4} (010) surface modified by sulfur. The calculated formation energy indicates that the sulfur adsorption on the (010) surface of the LiFePO{sub 4} is energetically favored. Sulfur is found to form Fe-S bond with iron. A much narrower band gap (0.67 eV) of the sulfur surface-modified LiFePO{sub 4} [S-LiFePO{sub 4} (010)] is obtained, indicating the better electronic conductive properties. By the nudged elastic band method, our calculations show that the activation energy of Li ions diffusion along the one-dimensional channel on the surface can be effectively reduced by sulfur surface modification. In addition, the surface diffusion coefficient of S-LiFePO{sub 4} (010) is estimated to be about 10{sup −11} (cm{sup 2}/s) at room temperature, which implies that sulfur modification will give rise to a higher Li ion carrier mobility and enhanced electrochemical performance.

• OSTI ID: 22314599
• Journal Information: Journal of Applied Physics, Vol. 116, Issue 6; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACTIVATION ENERGY
ADMINISTRATIVE PROCEDURES
ADSORPTION
CARRIER MOBILITY
DIFFUSION
ELECTROCHEMISTRY
FORMATION HEAT
IRON
LITHIUM IONS
MODIFICATIONS
PERFORMANCE
SULFUR
SURFACES
TEMPERATURE RANGE 0273-0400 K