# US 8,785,062 B2 · Fuel cell system comprising fuel cell stack, and method for producing fuel cell stack

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,785,062 B2
- Document ID: US8785062B2
- Status: Granted
- Kind: B2
- Application number: 12/616,488
- Filed: 2009-11-11
- Published: 2010-05-20
- Granted: 2014-07-22
- Earliest claimed: 2008-11-14
- Assignees: Panasonic Corporation
- Applicants: Hiroaki Matsuda; Takashi Akiyama
- Inventors: Hiroaki Matsuda; Takashi Akiyama
- Web page: https://patentgrep.com/patent/US8785062B2

## CPC

- H01M 8/04007: related to heat exchange
- H01M 8/04126: {Humidifying}
- H01M 8/04492: Humidity; Ambient humidity; Water content
- H01M 8/04828: Humidity; Water content
- Y02E 60/50: Fuel cells
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- Y10T 29/49108: Electric battery cell making
- H01M: PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

The fuel cell system of the present invention includes: (A) a fuel cell stack including at least one unit fuel cell including a cathode, an anode, and a polymer electrolyte membrane interposed therebetween; (B) a detecting device for detecting lack of humidification in the fuel cell stack; (C) a water supplying device for supplying moisture to the fuel cell stack when lack of humidification is detected by the detecting device; (D) a heating device for heating the supplied moisture; and (E) a cooling device for cooling the supplied moisture. In the fuel cell system of the present invention, the fuel cell stack is humidified by repeating heating and cooling of the supplied moisture by the heating device and the cooling device, respectively.

## Claims

### Claim 1

A fuel cell system comprising:
(A) a fuel cell stack comprising at least one unit fuel cell comprising a cathode, a anode, and a polymer electrolyte membrane interposed therebetween;
(B) a detecting device for detecting lack of humidification in said fuel cell stack;
(C) a water supplying device for supplying moisture to said fuel cell stack when lack of humidification is detected by said detecting device;
(D) a heating device for heating said supplied moisture;
(E) a cooling device for cooling said supplied moisture; and
(F) a humidification control device programmed to control said heating device and said cooling device such that when said detecting device detects lack of humidification, a humidification process is repeated alternately, the humidification process comprising: heating of moisture in said fuel cell stack to a first predetermined temperature; and
cooling of said moisture to a second predetermined temperature.

### Claim 2 (depends on 1)

The fuel cell system in accordance with claim 1, wherein, in a case where hydrogen gas is supplied as fuel to said anode, said fuel cell system includes a fuel cell stack heating device for heating said fuel cell stack, and said fuel cell stack heating device functions as said heating device for heating said supplied moisture.

### Claim 3 (depends on 1)

The fuel cell system in accordance with claim 1, wherein, in a case where an aqueous methanol solution is supplied as fuel to said anode, said fuel cell system includes a fuel supplying device for supplying said fuel to said anode and a fuel cell stack cooling device for cooling said unit fuel cell, and said fuel supplying device functions as said water supplying device and said fuel cell stack cooling device functions as said cooling device for cooling said supplied moisture.

### Claim 4 (depends on 1)

The fuel cell system in accordance with claim 1, wherein said detecting device comprises:
(G) a measuring device for measuring an output power, an internal resistance, or a hibernation time, of said fuel cell stack; and
(H) a determining device for determining whether or not there is the lack of humidification in said fuel cell stack, based on information obtained by said measuring device.

### Claim 5 (depends on 4)

The fuel cell system in accordance with claim 4, wherein said humidification control device controls said heating device and said cooling device such that said humidification process is repeated until the output power of said fuel cell stack measured by said measuring device reaches a predetermined value or higher.

### Claim 6 (depends on 4)

The fuel cell system in accordance with claim 4, wherein said humidification control device controls said heating device and said cooling device such that said humidification process is repeated until the internal resistance of said fuel cell stack measured by said measuring device reaches a predetermined value or higher.

### Claim 7 (depends on 1)

The fuel cell system in accordance with claim 1, further comprising:
(I) a temperature controlling device for adjusting a temperature of said supplied moisture near to an operating temperature of said fuel cell stack by heating by said heating device; and adjusting the temperature of said supplied moisture near to room temperature by cooling by said cooling device.

### Claim 8 (depends on 1)

The fuel cell system in accordance with claim 1, wherein said humidification control device controls said heating device and said cooling device such that said humidification process is carried out for a predetermined number of cycles.

### Claim 9 (depends on 8)

The fuel cell system in accordance with claim 8, wherein said predetermined number of cycles is three to ten.

### Claim 10 (depends on 1)

The fuel cell system in accordance with claim 1, wherein said first predetermined temperature is 50 to 80° C.

### Claim 11 (depends on 1)

The fuel cell system in accordance with claim 1, wherein said second predetermined temperature is 15 to 35° C.