In situ thermal polymerization method for making gel polymer lithium ion rechargeable electrochemical cells
US7422826B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 2004 |
| Grant date | Sep 9, 2008 |
| Priority date | — |
| Expiry date | Nov 10, 2026 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T29/49108
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A single step, in situ curing method for making gel polymer lithium ion rechargeable cells and batteries is described. This method used a precursor solution consisting of monomers with multiple functionalities such as multiple acryloyl functionalities, a free-radical generating activator, nonaqueous solvents such as ethylene carbonate and propylene carbonate, and a lithium salt such as LiPF6. The electrodes are prepared by slurry-coating a carbonaceous material such as graphite onto an anode current collector and a lithium transition metal oxide such as LiCoO2 onto a cathode current collector, respectively. The electrodes, together with a highly porous separator, are then soaked with the polymer electrolyte precursor solution and sealed in a cell package under vacuum. The whole cell package is heated to in situ cure the polymer electrolyte precursor. The resulting lithium ion rechargeable cells with gelled polymer electrolyte demonstrate excellent electrochemical properties such as high efficiency in material utilization, high Coulombic efficiency, good rate capability, and good cyclability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.