IP Library › Granted Patent US 7,029,792
Granted Patent B2
US 7,029,792 · App. 10/831,397 · Granted Apr 18, 2006

Recombinant separator

View Patent ↗
Loading inventors, assignments & file history…
Monitor This Case
Get email alerts when status or documents change.
Order Certified Copies
Most orders are placed with the USPTO same day — all within 24 business hours.
Order via The Patent Place →
Pre-filled with this patent's details
Quick Facts
Patent No.
US 7,029,792
App. No.
10/831,397
Granted
Apr 18, 2006
Kind
B2
Abstract

A heterogeneous, cellulose battery separator made of a mixture of cellulose and a polymer with hydrogen permeability for use in zinc-based batteries exhibiting increased hydrogen transport through the membrane while maintaining low electrical impedance and exhibiting resistance to zinc ion transport preventing zinc dendrite formation.

Claims (13)

1. A secondary, zinc ion battery comprising in combination;

a battery case containing;

a body of alkaline electrolyte;

a zinc electrode disposed in said body of electrolyte;

a counter-electrode disposed in said body of electrolyte; and

a cellulose separator film having a thickness from 10 microns to 250 microns, being resistant to alkaline electrolyte, being impermeable to zinc ions containing a continuous cellulose phase and a dispersion of discrete domains of polymer having a high hydrogen permeability of at least 1×10 −13 cm 3 cm −1 s −1 Pa −1 , within said cellulose phase said film being impermeable to hydrogen except where said discrete polymer domains of high hydrogen permeability are present in said film and said discrete domains of high hydrogen permeability polymer are present in said film in an amount of 10 to 60 parts by weight to 100 parts of the cellulose film, and said separator film is disposed in said body of electrolyte between said electrodes.

2. A battery according to claim 1 in which the cellulose is crosslinked with a hydrocarbon bridge containing from 2 to 12 carbon atoms between cellulose chains.

3. A battery according to claim 2 in which the bridge is an alkylene bridge containing from 4 to 8 carbon atoms.

4. A secondary zinc battery according to claim 1 in which the counter-electrode comprises silver.

5. A secondary zinc battery according to claim 1 in which the polymer is present in said separator in an amount of 10 to 60 parts by weight to 100 parts by weight of cellulose.

6. A secondary zinc battery according to claim 5 in which the polymer is cellulose ether.

7. A secondary battery according to claim 6 in which the polymer is alkyl cellulose.

8. A secondary battery according to claim 7 in which the polymer is ethyl cellulose.