Nanocrystalline Li{sub x}Mn{sub 2{minus}y}O{sub 4} cathodes for solid-state thin-film rechargeable lithium batteries

Journal Article · Thu Jul 01 04:00:00 EDT 1999 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/1.1391955· OSTI ID:680044

Dudney, N J; Bates, J B; Zuhr, R A ^[1]; Young, S; Robertson, J D ^[2]; Jun, H P; Hackney, S A ^[3]

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1. Oak Ridge National Lab., TN (United States). Solid State Div.
2. Univ. of Kentucky, Lexington, KY (United States). Dept. of Chemistry
3. Michigan Technological Univ., Houghton, MI (United States). Dept. of Metallurgical and Materials Engineering

Thin-film cathodes of lithium manganese oxide, 0.3--3 {micro}m thick, were deposited by rf magnetron sputtering of a LiMn{sub 2}O{sub 4} ceramic target onto unheated substrates. The resulting films were dense, {approximately}4.2 g/cm{sup 3}, with a {approximately}50 {angstrom} nanocrystalline spinel structure. The film composition was typically Li{sub x}Mn{sub 2{minus}y}O{sub 4} with y {approximately} 0.3 and 1.2 < x < 2.2. When cycled in a thin-film rechargeable lithium battery, specific cathode capacities of 145 {+-} 23 and {approximately}270 mAh/g were realized for discharge from 4.5 V to either 2.5 or 1.5 V, respectively. The discharge and charge current densities were limited by the resistivity of lithium transport into and through the cathode. After thousands of cycles at 25 C, there was a small increase in cell resistance. After several hundred cycles at 100 C, the discharge curves developed a stable knee at {approximately}4 V characteristic of crystalline LiMn{sub 2}O{sub 4} cathodes. The polarization of the discharge/charge cycles were interpreted in terms of free energy of mixing curves.

• Sponsoring Organization: USDOE, Washington, DC (United States)
• DOE Contract Number: AC05-96OR22464
• OSTI ID: 680044
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 7 Vol. 146; ISSN 0013-4651; ISSN JESOAN
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
36 MATERIALS SCIENCE
BULK DENSITY
CATHODES
CHEMICAL COMPOSITION
CRYSTAL STRUCTURE
ELECTRICAL PROPERTIES
FABRICATION
LITHIUM OXIDES
MANGANESE OXIDES
METAL-NONMETAL BATTERIES