Sol-gel synthesis of manganese oxides

Journal Article · Mon Oct 01 00:00:00 EDT 1990 · Journal of Solid State Chemistry; (USA)

DOI:https://doi.org/10.1016/0022-4596(90)90228-P· OSTI ID:6181709

Bach, S; Henry, M; Baffier, N; Livage, J ^[1]

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1. Ecole Nationale Superieure de Chimie de Paris (France)

Transparent and stable manganese dioxide gels are obtained upon reduction of permanganate aqueous solutions AMnO{sub 4} (A = Li, Na, K, NH{sub 4}, N(CH{sub 3}){sub 4}) by fumaric acid. All xerogels are amorphous when dried at room temperature. Their thermal behavior however depends on the nature of the counter cation A{sup +}. Ammonium permanganates lead to the formation of {alpha}- or {gamma}-Mn{sub 2}O{sub 3} while AMnO{sub 2} mixed oxides are obtained at high temperature when A = Li, Na, K. Other crystalline phases such as LiMn{sub 2}O{sub 4} or Na{sub 0.7}MnO{sub 2} are also formed at lower temperature around 500{degree}C. Oxidation of these mixed oxides into sulfuric acid lead to the formation of {lambda}- or {delta}-MnO{sub 2} while A{sup +} and Mn{sup 2+} ions are released into the solution. Such manganese dioxides could be good candidates for making reversible cathodes in nonaqueous lithium batteries.

• OSTI ID: 6181709
• Journal Information: Journal of Solid State Chemistry; (USA), Vol. 88:2; ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
MAGNESIUM OXIDES
CHEMICAL PREPARATION
AQUEOUS SOLUTIONS
FUMARIC ACID
LITHIUM
POTASSIUM
SODIUM
SOL-GEL PROCESS
ALKALI METALS
ALKALINE EARTH METAL COMPOUNDS
CARBOXYLIC ACIDS
CHALCOGENIDES
DICARBOXYLIC ACIDS
DISPERSIONS
ELEMENTS
MAGNESIUM COMPOUNDS
METALS
MIXTURES
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
SOLUTIONS
SYNTHESIS
360201* - Ceramics
Cermets
& Refractories- Preparation & Fabrication