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

Related Subjects

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