Fuel-cell unit cell and manufacturing method therefor

Patent metadata

Field	Value
Publication number	US-2018026291-A1
Application number	US-201715626739-A
Country	US
Kind code	A1
Filing date	Jun 19, 2017
Priority date	Jul 25, 2016
Publication date	Jan 25, 2018
Grant date	—

Abstract

A fuel-cell unit cell comprises an MEGA plate with a resin frame, and two separators. There is formed a gas manifold hole in an outer edge portion of the resin frame. There is provided a gas-flow-path forming portion with a recessed-and-protruded shape on the first surface of the resin frame for forming gas flow paths between the gas manifold hole and the first surface of the MEGA. There is also formed a fusion-bonding portion for surrounding a periphery of the gas manifold hole to cut off gas circulation between the gas manifold hole and the second surface of the MEGA and for bonding the resin frame and the second separator with each other, on the second surface of the resin frame so as to pass across a backside of the gas-flow-path forming portion. The fusion-bonding portion is formed from a first resin, and the gas-flow-path forming portion is formed from a second resin higher in melting point than the first resin.

First claim

What is claimed is:

1 . A fuel-cell unit cell comprising:
a membrane-electrode gas-diffusion-layer assembly (MEGA) plate including an MEGA and a resin frame joined to a periphery of the MEGA; a first separator placed in contact with a first surface of the MEGA and also placed on a first-surface side of the resin frame; and a second separator placed in contact with a second surface of the MEGA and also placed on a second-surface side of the resin frame; wherein a gas manifold hole is formed in an outer edge portion of the resin frame, the fuel-cell unit cell further comprising: a gas-flow-path forming portion with a recessed-and-protruded shape, provided on the first surface of the resin frame, for forming gas flow paths between the gas manifold hole and the first surface of the MEGA; and a fusion-bonding portion for surrounding a periphery of the gas manifold hole to cut off gas circulation between the gas manifold hole and the second surface of the MEGA and for bonding the resin frame and the second separator with each other, the fusion-bonding portion being formed on the second surface of the resin frame so as to pass across a backside of the gas-flow-path forming portion, wherein the fusion-bonding portion is formed from a first resin, and the gas-flow-path forming portion is formed from a second resin higher in melting point than the first resin.

2 . The fuel-cell unit cell in accordance with claim 1 , wherein
the resin frame has a rectangular frame-like shape, the gas manifold hole is formed at four corner positions of the resin frame, the resulting gas manifold holes including two first gas manifold holes formed at one pair of diagonal positions of the resin frame and two second gas manifold holes formed at the other pair of diagonal positions, the gas-flow-path forming portion provided on the first surface of the resin frame includes two first gas-flow-path forming portions for forming gas flow paths between each of the two first gas manifold holes and the first surface of the MEGA, the fuel-cell unit cell further comprises two second gas-flow-path forming portions with a recessed-and-protruded shape for forming gas flow paths between each of the two second gas manifold holes and the second surface of the MEGA on the second surface of the resin frame, independent of the fusion-bonding portion provided on the second surface of the resin frame, a first fusion-bonding portion is formed on the first surface of the resin frame so as to pass across backsides of the two second gas-flow-path forming portions such that the first fusion-bonding portion does not cut off gas circulation between each of the two first gas manifold holes and the first surface of the MEGA while the first fusion-bonding portion surrounds each of the two second gas manifold holes to cut off gas circulation between each of the two second gas manifold holes and the first surface of the MEGA, and the first fusion-bonding portion bonds the resin frame and the first separator with each other, the fusion-bonding portion provided on the second surface of the resin frame includes a second fusion-bonding portion which is formed so as to pass across backsides of the two first gas-flow-path forming portions such that the second fusion-bonding portion does not cut off gas circulation between each of the two second gas manifold holes and the second surface of the MEGA while the second fusion-bonding portion surrounds each of the two first gas manifold holes to cut off gas circulation between each of the two first gas manifold holes and the second surface of the MEGA, and the second fusion-bonding portion bonds the resin frame and the second separator with each other, and the first fusion-bonding portion and the second fusion-bonding portion are formed from the first resin, and the two first gas-flow-path forming portions and the two second gas-flow-path forming portions are formed from the second resin.

3 . The fuel-cell unit cell in accordance with claim 2 , wherein
the two first gas-flow-path forming portions and the two second gas-flow-path forming portions are formed at mutually non-overlapping positions when projected and observed along a stacking direction in which a plurality of the fuel-cell unit cells are to be stacked together.

4 . The fuel-cell unit cell in accordance with claim 1 , wherein
the resin frame includes an inner frame joined to a periphery of the MEGA and an outer frame joined to a periphery of the inner frame, the outer frame is joined to the first separator and the second separator, and Young's modulus of the inner frame is smaller than Young's modulus of the outer frame.

5 . The fuel-cell unit cell in accordance with claim 1 , further comprising:
a seal gasket which is to be put into contact with the second separator of neighboring another fuel-cell unit cell when a plurality of the fuel-cell unit cells are to be stacked together, the seal gasket being formed on a cooling surface out of two surfaces of the first separator, the cooling surface being opposed to the surface which is placed on the first-surface side of the resin frame, the seal gasket being disposed such that the seal gasket passes across a position overlapping with the gas-flow-path forming portion when projected and observed along a stacking direction in which a plurality of the fuel-cell unit cells are to be stacked together.

6 . A method of manufacturing a fuel-cell unit cell comprising the steps of:
(a) preparing a membrane-electrode gas-diffusion-layer assembly (MEGA) plate including an MEGA and a resin frame joined to a periphery of the MEGA, a first separator to be placed in contact with a first surface of the MEGA and also placed on a first-surface side of the resin frame, and a second separator to be placed in contact with a second surface of the MEGA and also placed on a second-surface side of the resin frame; and (b) stacking the first separator, the MEGA plate, and the second separator to assemble the fuel-cell unit cell, wherein a gas manifold hole is formed in an outer edge portion of the resin frame, a gas-flow-path forming portion with a recessed-and-protruded shape for forming gas flow paths between the gas manifold hole and the first surface of the MEGA is formed on the first surface of the resin frame, a thermoplastic bonding portion for surrounding a periphery of the gas manifold hole to cut off gas circulation between the gas manifold hole and the second surface of the MEGA and for bonding the resin frame and the second separator with each other is formed on the second surface of the resin frame so as to pass across a backside of the gas-flow-path forming portion, the thermoplastic bonding portion is formed from a first resin and the gas-flow-path forming portion is formed from a second resin higher in melting point than the first resin, and the step (b) includes a step of, after the stacking, compressing the gas-flow-path forming portion and the thermoplastic bonding portion of the resin frame from outside of the first separator and the second separator while heating the gas-flow-path forming portions and the thermoplastic bonding portion at a temperature which is not lower than a melting point of the thermoplastic bonding portion and also which is lower than a melting point of the gas-flow-path forming portion so as to fuse the thermoplastic bonding portion to form a fusion-bonding portion bonded to the second separator.

7 . The method in accordance with claim 6 , wherein
the resin frame has a rectangular frame-like shape, the gas manifold hole is formed at four corner positions of the resin frame, the resulting gas manifold holes including two first gas manifold holes formed at one pair of diagonal positions of the resin frame and two second gas manifold holes f

Assignees

• Toyota Motor Co Ltd

Inventors

• Okada Sachio
• Kurihara Takuya
• Shizuku Fumishige
• Murayama Ryogo
• Kamiya Makoto

Classifications

• H01M8/0284

  Organic resins; Organic polymers · CPC title

• H01M8/2465

  Details of groupings of fuel cells · CPC title

• H01M8/0297 Primary

  Arrangements for joining electrodes, reservoir layers, heat exchange units or bipolar separators to each other (H01M8/0271 takes precedence) · CPC title

• H01M8/0267

  having heating or cooling means, e.g. heaters or coolant flow channels · CPC title

• H01M8/248

  Means for compression of the fuel cell stacks · CPC title