Lithium diffusion mechanisms in layered intercalation compounds

• Published in: Journal of power sources Vol. 97; pp. 529 - 531
• Main Authors: Van der Ven, A., Ceder, G.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Lausanne Elsevier B.V 01-07-2001; Elsevier Sequoia
• Subjects: Applied sciences; Direct energy conversion and energy accumulation; Electrical engineering. Electrical power engineering; Electrical power engineering; Electrochemical conversion: primary and secondary batteries, fuel cells; Exact sciences and technology; First-principles; Li xCoO 2; Lithium diffusion; Li x CoO 2; Lithium diffusion; First-principles; Cobalt oxide; Ternary compound; Alkali metal Compounds; Transition metal Compounds; Theoretical study; Activation parameter; Secondary cell; Electrode material; Electric batteries; Lattice parameters; Intercalation compound; Metal metal oxide batteries; Vacancy density; Thermodynamic model; Lithium oxide; Diffusion coefficient; Crystalline structure
• ISSN: 0378-7753; 1873-2755
• DOI: 10.1016/S0378-7753(01)00638-3

We investigate the mechanisms of lithium diffusion in layered intercalation compounds from first-principles. We focus on Li
x
CoO
2 and find that lithium diffusion in this compound occurs predominantly with a divacancy mechanism. First-principles calculations predict that the activation barrier is very sensitive to the lithium concentration due to the strongly varying
c-lattice parameter of the host and the change in effective valence of the cobalt ions. This translates into a diffusion coefficient that varies by several orders of magnitude with state of charge.