Room temperature single phase Li insertion/extraction material for use in Li-based battery
US8641921B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Mar 19, 2008 |
| Grant date | Feb 4, 2014 |
| Priority date | — |
| Expiry date | Jul 15, 2030 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2982
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to active materials for the manufacture of Li-based batteries. A crystalline nanometric powdered material with formula Lix(M, M′)PO4, in particular LixFePO4 (O≦x≦1), is disclosed, exhibiting single phase Li insertion/extraction mechanism at room temperature when used as positive electrode material in Li-based batteries. Compared to current LiFePO4, the novel material results in smooth, sloping charge/discharge voltage curve greatly simplifying the monitoring of the state of charge of the batteries. The coexistence of mixed valence states for Fe (i.e. FeIIIVFeII) is believed to increase the electronic conductivity in the room temperature single phase LixFePO4 material, compared to state of the art two-phase materials. This, together with the nanometric size of the particles and their sharp monomodal size distribution, contributes to the exceptional high-rate capability demonstrated in batteries.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.