Method of making polymeric electrolytic cell separator membrane
US5607485A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 19, 1995 |
| Grant date | Mar 4, 1997 |
| Priority date | — |
| Expiry date | May 19, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49115
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A flexible polymeric film useful as an interelectrode separator or electrolyte member in electrolytic devices, such as rechargeable batteries, comprises a copolymer of vinylidene fluoride with 8 to 25% hexafluoropropylene. The film may be cast or formed as a self-supporting layer retaining about 20% to 70% of a high-boiling solvent plasticizer or plasticizer mixture comprising such solvents as ethylene carbonate, propylene carbonate, dimethyl carbonate, and dibutyl phthalate. The film may be used in such form or after extracting of the retained plasticizer with a film-inert low-boiling solvent to provide a separator member into which a solution of electrolytic salt is subsequently imbibed to displace retained plasticizer or replace plasticizer previously extracted from the polymeric matrix.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.