Li Diffusion and High-Voltage Cycling Behavior of Thin-Film LiCoO2 Cathodes
Mass transport and thermodynamic properties of Li{sub x}CoO{sub 2} were studied by the potentiostatic intermittent titration technique (PITT) using solid-state thin-film batteries that provide a well-defined diffusion geometry. Both the chemical diffusion coefficient and the thermodynamic factor have minima at the phase boundaries of the Li/vacancy ordered phase ''Li{sub 0.5}CoO{sub 2}''. The self-diffusion coefficient of Li has a minimum at x = 0.5 associated with the Li/vacancy ordering. As the degree of ordering increases, the nonmonotonic variations become more pronounced when approaching x = 0.5 in Li{sub x}CoO{sub 2}. We also show that thin-film LiCoO{sub 2} cathodes having grains of sub-micrometer size combined with the Li upon electrolyte exhibit excellent capacity retention when charged up to 4.5 V.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- AC05-00OR22725
- OSTI ID:
- 788508
- Report Number(s):
- P01-110459; TRN: US200201%%219
- Resource Relation:
- Conference: 200th Mtg of the Electrochem. Society, 52nd Mtg of the Intl' Society of Electrochemistry, San Francisco, CA (US), 09/02/2001--09/07/2001; Other Information: PBD: 2 Oct 2001
- Country of Publication:
- United States
- Language:
- English
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