Perforated current collectors for storage batteries and electrochemical cells, having improved resistance to corrosion
US6802917B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | May 26, 2000 |
| Grant date | Oct 12, 2004 |
| Priority date | — |
| Expiry date | May 26, 2020 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A process for enhancing chemical stability and corrosion resistance is described for perforated current collectors made by continuous production processes for use in electrochemical cells, including storage batteries such as lead-acid batteries. The process relies on utilizing a strip processing method, selected from the group of reciprocating expansion, rotary expansion and punching, to perforate the solid metal strip to form a grid or mesh, as a deformation treatment. The perforation-deformation treatment is followed in rapid succession by a heat-treatment to obtain a recrystallized microstructure in the current collector and optionally by quenching to rapidly reduce the temperature to below approximately 80° C. The process yields an improved microstructure consisting of a high frequency of special low &Sgr; CSL grain boundaries (>50%), exhibiting significantly improved resistance to intergranular corrosion and cracking. Perforated current collectors produced with this process from a solid lead-alloy strip exhibit superior growth and corrosion properties when employed as positive grids in a lead-acid battery.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.