A lithium insertion-type positive electrode material based on an orthosilicate structure and electrical generators and variable optical transmission devices of this material are provided.

Lithium insertion electrode materials based on orthosilicates derivatives

The present invention is one which provides a production process for lithium-silicate-system compound, the production process being characterized in that : a lithium-silicate compound being expressed by Li 2 SiO 3 is reacted with a substance including at least one member of transition-metal elements that is selected from the group consisting of iron and manganese at 400-650 °C in a molten salt of a carbonate mixture comprising lithium carbonate and at least one member of alkali-metal carbonates that is selected from the group consisting of potassium carbonate, sodium carbonate, rubidium carbonate and cesium carbonate in a mixed-gas atmosphere including carbon dioxide and a reducing gas; and a positive-electrode active material for lithium-ion secondary battery that comprises a lithium-silicate-system compound being obtained by the aforesaid process. In accordance with the present invention, it becomes feasible to produce lithium-silicate-system materials, which are useful as positive-electrode active materials for lithium-ion secondary battery, and the like, by means of relatively simple and easy means.

Method for producing lithium silicate compound

The present invention allows production of a battery which not only excels in terms of safety and cost, but also has a long life A cathode active material of the present invention is represented by the following General Formula (1) : Li y K a Fe1-x X x PO4   (1), where X is at least one element of groups 2 through 13; 0<a<=025; 0<=x<=025; and y is (1-a), a volume of a unit lattice for a case in which y in General Formula (1) is (x-a) (when x-a<0, y is 0) having a change ratio of not more than 4% with respect to a volume of a unit lattice for a case in which y in General Formula (1) is (1-a)

Cathode active material, cathode and nonaqueous secondary battery

Sol–gel derived nanostructured Li2MnSiO4/C cathode with high storage capacity

PROBLEM TO BE SOLVED: To provide a nonaqueous electrolyte secondary battery with an increased theoretical capacity, high operating potential, and excellent in reversible capacitance density. SOLUTION: The cathode active material for the nonaqueous electrolyte secondary battery contains a solid solution compound expressed in general formula (I): Li 2-X MSiO 4 (in the formula, M indicates transition metal including at least Co or Mn, X=0≤X≤2). COPYRIGHT: (C)2008,JPO&INPIT

Cathode active material for nonaqueous electrolyte secondary battery and battery

Orthosilicates containing the SiO 4 4- tetranion as the building block are used as
redox materials by incorporation of at least one transition elements with at least two
valency levels. Lithium ingresses or egresses from the structure to compensate for the
valency change of the redox couples during electrode operation and keep overall
electroneutrality.

Nathalie Ravet

Papers

New lithium insertion electrode materials based on orthosilicate derivatives