Positive electrode active material for non-aqueous electrolyte secondary cell
US7794879B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Mar 30, 2005 |
| Grant date | Sep 14, 2010 |
| Priority date | — |
| Expiry date | Jul 10, 2025 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A positive electrode active material for a non-aqueous electrode secondary cell which comprises a composite oxide containing iron and sodium as main components, having a hexagonal crystal structure, and exhibiting a value obtained by dividing the intensity of a peak corresponding to an interplanar spacing of 2.20 Å by the intensity of a peak corresponding to an interplanar spacing of 5.36 Å of 2 or less in the X-ray diffraction analysis of said composite oxide; and a method for preparing the positive electrode active material wherein the above composite oxide is prepared by heating a metal compound mixture mainly containing a sodium compound and an iron compound in the temperature range of 400 to 900° C., which comprises heating the metal compound mixture in an inert atmosphere in the temperature range of less than 100° C. on the way of the rise in the temperature. The use of the above active material allows the manufacture of a cell which is free from the rapid reduction of the discharge voltage with the progress of discharge.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.