A PRODUCTION PROCESS FOR LITHIUM-SILICATE-SYSTEM COMPOUND, A POSITIVE-ELECTRODE ACTIVE MATERIAL COMPRISING THE LITHIUM-SILICATE-SYSTEM COMPOUND OBTAINED BY THE PRODUCTION PROCESS FOR LITHIUM-ION SECONDARY BATTERY, A POSITIVE ELECTRODE INCLUDING THE LITHIUM-SILICATE-SYSTEM COMPOUND FOR LITHIUM-ION SECONDARY BATTERY, AND LITHIUM SECONDARY BATTERY

摘要

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.