# US 2008/0187818 A1 · Temperature dependent ionic gate

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- Number: US 2008/0187818 A1
- Document ID: US20080187818A1
- Status: Published application
- Kind: A1
- Application number: 11/702,236
- Filed: 2007-02-05
- Published: 2008-08-07
- Earliest claimed: 2007-02-05
- Assignees: Gas Technology Institute
- Inventors: Qinbai Fan
- Web page: https://patentgrep.com/patent/US20080187818A1

## CPC

- H01M 10/4235: {Safety or regulating additives or arrangements in electrodes, separators or electrolyte (H01M10/4242 takes precedence)}
- C25B 13/08: based on organic materials
- G01N 27/40: Semi-permeable membranes or partitions
- H01M 8/0289: Means for holding the electrolyte (solid polymer electrolytes H01M8/1018)
- H01M 2300/0002: Aqueous electrolytes
- H01M 2300/0017: Non-aqueous electrolytes
- Y02E 60/10: Energy storage using batteries
- Y02E 60/50: Fuel cells
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- C25B: ELECTROLYTIC OR ELECTROPHORETIC PROCESSES FOR THE PRODUCTION OF COMPOUNDS OR NON-METALS; APPARATUS THEREFOR (anodic or cathodic protection C23F13/00; single-crystal growth C30B)
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION

## Abstract

An electrochemical device having a liquid electrolyte which includes a protic solvent, an anode electrode disposed in contact with the liquid electrolyte, and a cathode electrode disposed in contact with the liquid electrolyte. A membrane which interrupts the transport of ions between the electrodes at a predetermined temperature is disposed in the liquid electrolyte between the anode electrode and the cathode electrode. In this way, electrochemical devices such as batteries, fuel cells, electrolyzers, and sensors, which may overheat during use and cause a fire or explosion, are precluded from overheating.

## Claims

### Claim 1

An electrochemical device comprising:
a liquid electrolyte comprising a protic solvent;
an anode electrode disposed in contact with said liquid electrolyte;
a cathode electrode disposed in contact with said liquid electrolyte; and
ion transport interruption means for interrupting transport of ions between said electrodes at a predetermined temperature disposed in said liquid electrolyte between said anode electrode and said cathode electrode.

### Claim 2 (depends on 1)

An electrochemical device in accordance with claim 1, wherein said ion transport interruption means comprises a membrane having temperature-dependent ion permeability.

### Claim 3 (depends on 1)

An electrochemical device in accordance with claim 1, wherein said ion transport interruption means comprises a membrane having temperature-dependent wettability in a protic solvent.

### Claim 4 (depends on 2)

An electrochemical device in accordance with claim 2, wherein said membrane comprises a cellulosic material.

### Claim 5 (depends on 4)

An electrochemical device in accordance with claim 4, wherein said membrane comprises polyhydroxypropyl cellulose.

### Claim 6 (depends on 1)

An electrochemical device in accordance with claim 1, wherein said electrochemical device is a battery.

### Claim 7 (depends on 1)

An electrochemical device in accordance with claim 1, wherein said electrochemical device is a fuel cell.

### Claim 8 (depends on 1)

An electrochemical device in accordance with claim 1, wherein said electrochemical device is an electrolyzer.

### Claim 9 (depends on 1)

An electrochemical device in accordance with claim 1, wherein said electrochemical device is a sensor.

### Claim 10 (depends on 1)

An electrochemical device in accordance with claim 1, wherein said electrochemical device is an ionic switch.

### Claim 11 (depends on 2)

An electrochemical device in accordance with claim 2, wherein said membrane is ion permeable up to a temperature of about 150° C.

### Claim 12 (depends on 4)

An electrochemical device in accordance with claim 4, wherein said cellulosic material is cross-linked.

### Claim 13

In an electrochemical device having a liquid electrolyte, an anode electrode disposed in contact with said liquid electrolyte, and a cathode electrode disposed in contact with said liquid electrolyte, a method for preventing a fire or explosion in said electrochemical device comprising the steps of:
inserting a membrane having temperature-dependent ion permeability into said liquid electrolyte between said anode electrode and said cathode electrode.

### Claim 14 (depends on 13)

A method in accordance with claim 13, wherein said electrolyte comprises a protic solvent.

### Claim 15 (depends on 13)

A method in accordance with claim 13, wherein said membrane comprises a cellulosic material.

### Claim 16 (depends on 15)

A method in accordance with claim 15, wherein said cellulosic material is cross-linked.

### Claim 17 (depends on 15)

A method in accordance with claim 15, wherein said membrane comprises polyhydroxypropyl cellulose.

### Claim 18 (depends on 16)

A method in accordance with claim 16, wherein said cellulosic material is cross-linked using glutaraldehyde as a cross-linking agent.

### Claim 19 (depends on 13)

A method in accordance with claim 13, wherein said electrochemical device is selected from the group consisting of a battery, a fuel cell, an electrolyzer, a sensor, and an ionic switch.

### Claim 20 (depends on 13)

A method in accordance with claim 13, wherein said membrane is ion permeable up to a temperature of about 150° C.