Exotic Manganese Dioxide Structures in Niobium Oxides Capacitors

Manganese Oxides : Battery Materials Make the Leap to Electrochemical Capacitors

Manganese oxides have a relatively long history in the world of battery chemistry, dating back to the work of Leclanché in the 1860s, which ultimately formed the basis for the now-ubiquitous primary 1.5 V Zn/ MnO2 alkaline cell.1 In the alkaline cell, manganese oxide (typically in the γMnO2 form) serves as the active cathode material, and stores charge via the insertion of protons from the aque...

Manganese oxides: parallels between abiotic and biotic structures.

A large number of microorganisms are responsible for the oxidation of Mn(2+)((aq)) to insoluble Mn(3+/4+) oxides (MnO(x)()) in natural aquatic systems. This paper reports the structure of the biogenic MnO(x)(), including a quantitative analysis of cation vacancies, formed by the freshwater bacterium Leptothrix discophora SP6 (SP6-MnO(x)()). The structure and the morphology of SP6-MnO(x)() were ...

Self-assembled manganese dioxide nanowires as electrode materials for electrochemical capacitors

Niobium Powder Synthesized by Calciothermic Reduction of Niobium Hydroxide for Use in Capacitors

Metallic niobium powder was produced for applications in electric capacitors via calciothermic reduction of niobium hydroxide in molten CaCl2. Sub-micrometer spherical metallic particles with coral-like morphologies reflected the particle size of the starting oxide powder. A fine powder was obtained from the mixtures of niobium hydroxide and CaO or Ca(OH)2, respectively. Sintered pellets of the...

Microbial formation of manganese oxides.

Microbial manganese oxidation was demonstrated at high Mn concentrations (5 g/liter) in bacterial cultures in the presence of a microalga. The structure of the oxide produced varied depending on the bacterial strain and mode of culture. A nonaxenic, acid-tolerant microalga, a Chlamydomonas sp., was found to mediate formation of manganite (gamma-MnOOH). Bacteria isolated from associations with c...