Amorphous carbon electrode and a secondary battery having such an electrode
US5773167A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 3, 1996 |
| Grant date | Jun 30, 1998 |
| Priority date | — |
| Expiry date | Jun 3, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02P70/50
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An amorphous carbon material, especially for an electrode of a lithium ion secondary battery, is characterized by an interlayer spacing d(002), obtained from the X-ray diffraction line assigned to the (002) plane of the carbon, of 0.345 nm to 0.365 nm, a ratio (Ps) os the number of carbon atoms involved in the layer structure to the total number of carbon atoms of from 0.54 to 0.85, and a ratio of the total nitrogen:total carbon atoms in the amorphous carbon of 0.005:1 to 0.055:1. The amorphous carbon material is prepared by applying a heat treatment to an amorphous carbon under under vacuum or inert gas atmosphere for at least 30 minutes to provide the desired crystalline structure. The carbon material may take the form of carbon fiber material, especially short carbon fibers obtained by pulverizing larger carbon fibers. A lithium ion secondary battery containing an electrode comprising such an amorphous carbon material has a large discharge capacity and high charge-discharge cycle characteristics.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.