JP6703298B2 - Fuel cell - Google Patents

Description

The present invention relates to fuel cells.

When assembling the fuel cell, the gas flow path and the reaction surface of the fuel cell main body are present in the center, so it is necessary to fix the peripheral portion with bolts or the like. The fuel cell main body includes a plurality of cells including a solid polymer electrolyte membrane and a fuel electrode and an oxidation electrode arranged on both sides of the solid polymer electrolyte membrane. The fuel electrode and the oxidation electrode each have a catalyst layer and a gas diffusion layer. Since the degree of close contact between cells and each element constituting the cell greatly affects the performance of the fuel cell, various fuel cells having improved close contact have been studied.

For example, in Patent Document 1 below, a fuel including a cathode-side current collector plate and an anode-side current collector plate that are gradually thickened from an edge portion toward a central portion and have a bulge portion formed on a surface facing a solid polymer membrane. Batteries are disclosed.

JP 2012-64384 A

However, in the fuel cell described in Patent Document 1, the load cannot be uniformly applied to the entire surfaces of the fuel electrode and the oxidation electrode, and there is a possibility that the power generation efficiency may be deteriorated due to the uneven adhesion degree. It was

From the above, the present invention has been made in order to solve the above problems, a fuel that can uniformly apply a load over the entire surface of the electrode and improve the degree of adhesion Intended to provide batteries.

In the fuel cell according to the first invention for solving the above-mentioned problems, a cell in which electrodes having a catalyst layer and a gas diffusion layer are arranged on both sides of an electrolyte membrane, and a plurality of the cells are stacked via a separator, A pair of current collecting plates arranged outside the stacked cells, a pair of insulating plates arranged outside the pair of current collecting plates, and a pair arranged outside the pair of insulating plates. Of the end plate and fastening means for fastening the pair of end plates, wherein the current collector plate has a range in which the gas diffusion layer of the electrode and the current collector plate face each other. A first insulating plate that is in surface contact with the end plate, and the first insulating plate is formed in a convex shape so that the gas diffusion layer of the electrode and the current collecting plate are thicker than a range where they do not face each other. A second insulating plate having a recess into which the plate fits, the second insulating plate has an opening through which the current collector plate is exposed to the separator side, and the first insulating plate is And a pressing force applying means for applying a pressing force to the separator side .

A fuel cell according to a second invention for solving the above-mentioned problems is characterized in that, in the fuel cell according to the first invention, the current collector plate is in surface contact with the separator.

A fuel cell according to a third invention for solving the above-mentioned problems is the fuel cell according to the first or second invention, wherein the convex shape of the current collector plate has a stepped portion provided on the surface on the separator side. And the stepped portion is arranged outside the edge portion of the electrode.

According to the present invention, a load can be uniformly applied to the entire surface of the electrode to improve the degree of adhesion. As a result, the degree of adhesion can be made uniform and the power generation efficiency can be improved.

1 is a schematic configuration diagram of a fuel cell main body included in a fuel cell according to an embodiment of the present invention. It is explanatory drawing of the collector plate which the said fuel cell main body has, Comprising: The plane is shown in FIG. 2(a), and the II-II arrow cross section in FIG. 2(a) is shown in FIG. 2(a). It is a development view of an insulating plate included in the fuel cell body.

Fuel cells according to main embodiments of the present invention will be described below, but the present invention is not limited to the following embodiments.

[Main Embodiment]
A fuel cell according to a main embodiment of the present invention will be described based on FIGS. 1 to 3.

The fuel cell according to the present embodiment has a fuel cell body in which a supplied fuel (for example, hydrogen) and air chemically react inside to generate electricity. As shown in FIG. 1, the fuel cell main body 100 has a cell 10 including a solid polymer membrane 11, and a fuel electrode 13 and an oxidizing electrode 17 which are respectively arranged on both sides of the solid polymer electrolyte membrane 11. The fuel electrode 13 has a catalyst layer 14 arranged on the solid polymer electrolyte membrane 11 side and a gas diffusion layer 15 formed on the surface side of the catalyst layer 14 opposite to the solid polymer electrolyte membrane 11. The oxidizing electrode 17 has a catalyst layer 18 arranged on the solid polymer electrolyte membrane 11 side, and a gas diffusion layer 19 formed on the surface side of the catalyst layer 18 opposite to the solid polymer electrolyte membrane 11.

A plurality of cells 10 are stacked with a separator 21 in between and sandwiched between the separators 21 and 21 from the outside to form a cell stack 20. The cell stack body 20 is sandwiched by the end plates 60, 60 from both sides of the cell stack body 40 via the current collector plates 40, 40 and the insulating plates 50, 50, and these are integrally formed by a fastener (fastening means) of a bolt 71 and a nut 72. It is summarized. The coolant gasket 22 is arranged between the separator 21 and the cell 10 and between the separator 21 and the current collector 50. This prevents gas leakage from the inside to the outside.

As shown in FIGS. 2A and 2B, the current collector 40 has a current collector body 41 and a bus bar 42. The bus bar 42 is provided so as to be connected to one side surface portion (back surface portion) 41b of the current collector body 41. A fixing hole 42d is provided on the tip side of the bus bar 42. By fixing a lead wire (not shown) to the fixing hole 42d with a bolt and a nut (not shown), electricity obtained inside the fuel cell main body 100 can be taken out to the outside.

The current collector plate body 41 has a rectangular shape in a plan view. The current collector plate body 41 has a protrusion 43 provided on the other side surface portion (surface portion) 41a side. That is, the current collector plate body 41 and the protruding portion 43 form a convex shape. The protruding portion 43 is arranged at a position facing the catalyst layers 14 and 18 (reaction surface) of the fuel electrode 13 and the oxidation electrode 17 when laminated. The surface portion 43a of the protruding portion 43 has a flat surface. The thickness t2 of the protrusion 43 is the same throughout. The thickness t2 of the protruding portion 43 is preferably smaller than the thickness t1 of the current collector plate body 41. The protrusion 43 has a shape wider than the catalyst layers 14 and 18 (reaction surface) of the fuel electrode 13 and the oxidation electrode 17. Therefore, the step portion 44 in which the protruding portion 43 is provided on the collector plate body 41 is arranged outside the reaction surfaces of the fuel electrode 13 and the oxidizing electrode 17 when laminated.

As shown in FIGS. 1 and 3, the insulating plate 50 is arranged outside the cell stacked body 20 with the current collector plate 40 interposed therebetween. The insulating plate 50 has a first insulating plate body 51 and a second insulating plate body 52. The first insulating plate body 51 has a substantially rectangular parallelepiped shape. The first insulating plate main body 51 has a concave portion 51ga which is provided on one side surface portion (surface portion) 51a side and into which the bus bar 42 of the collector plate 40 can be fitted. The first insulating plate body 51 has a liquid gasket groove 51gb provided at a position surrounding the outside of the edge portion (outer peripheral portion) 41c of the current collector plate body 41 when laminated. By inserting a liquid gasket (not shown) in the liquid gasket groove 51gb, the area surrounded by the liquid gasket groove 51gb is sealed between the liquid gasket groove 51gb and the second insulating plate body 52. It should be noted that bolt holes 51da and 51db, through which the shaft portion 71b of the bolt 71 can be inserted, are provided near the upper end portion 51ca and the lower end portion 51cb of the first insulating plate body 51, respectively. Positioning holes 51dc and 51dd are provided in the lateral center of the first insulating plate body 51 near the upper end 51ca and the lower end 51cb, respectively.

The first insulating plate body 51 has a bolt hole 51k which is provided at the center in the vertical direction and which penetrates the front surface portion 51a and the back surface portion (the other side surface portion) 51b. The bolt hole 51k is capable of meshing with the threaded portion of the shaft portion 53b of the bolt 53 which is a pressing tool (pressing force applying means) for pressing the current collector plate 40, which will be described in detail later. The bolt holes 51k are provided at two locations in the left-right direction.

The second insulating plate body 52 has a recess 52f and an opening 52e. The recess 52f is provided in the side surface portion (back surface portion) 52b on the first insulating plate body 51 side (end plate side). The recess 52f has a shape into which the first insulating plate body 51 can be fitted. The opening 52e communicates one side surface portion (front surface portion) 52a and the other side surface portion (back surface portion) 52b of the second insulating plate body 52. In the vicinity of the upper end portion 52ca and the lower end portion 52cb of the second insulating plate body 52, corresponding to the bolt holes 51da, 51db of the first insulating plate body 51, bolt holes 52da, 52db through which the shaft portion 71b of the bolt 71 can be inserted. Are provided respectively. Further, a positioning hole 52dc corresponding to the positioning hole 51dc of the first insulating plate body 51 is provided in the lateral center of the second insulating plate body 52 near the upper end 52ca. The second insulating plate main body 52 has a lateral center near the lower end 52ca corresponding to the positioning hole 51dd of the first insulating plate main body 51, and a positioning hole (not shown) similar to the lateral center near the upper end 52ca. Is provided.

The second insulating plate body 52 further has flange portions 52i, 52i provided on the side portions. The flange portion 52i is provided with a fuel gas passage 52ha, an oxidizing gas passage 52hb, and a water passage 52hc through which the fuel gas, the oxidizing gas, and the water respectively flow. Bolt holes 52dc into which the shaft portions 71b of the bolts 71 can be inserted are provided near the side end portions 52cc of the flange portions 52i. An O-ring 54 is arranged between the second insulating plate body 52 and the end plate 60 so as to correspond to the fuel gas passage 52ha, the oxidizing gas passage 52hb, and the water passage 52hc. This prevents leakage of fuel gas, oxidizing gas and water.

By using the insulating plate 50 having the first insulating plate body 51 and the second insulating plate body 52 described above, the surface of the protruding portion 43 provided on the other side surface portion (surface portion) 41a side of the current collecting plate body 41. The part 43a is exposed and arranged with respect to the separator 21 side. Further, by adjusting the amount of protrusion of the tip portion 53ba of the shaft portion 53b of the bolt 53 that meshes with the bolt hole 51k of the first insulating plate body 51 from the first insulating plate body 51 with a jig, the current collector plate 40 The magnitude of the force pushing the side surface portion of the cell stack 20 can be adjusted by the protruding portion 43 of. That is, it is possible to adjust the force for uniformly contacting the respective members of the cell stack 20 in the surface direction.

Therefore, in the fuel cell according to the present embodiment, in the current collector plate 40, the range in which the gas diffusion layers 15 and 19 of the fuel electrode 13 and the oxidation electrode 17 and the current collector plate 40 face each other is the fuel electrode 13 and the oxidation electrode. Since the gas diffusion layers 15 and 19 of the pole 17 and the current collector plate 40 are formed in a convex shape so as to be thicker than a non-opposing range, even if they are fastened with a fastening force of the same magnitude as the conventional one, it is possible to The gap becomes smaller. As a result, the fuel gas and the oxidizing gas efficiently react at the fuel electrode 13 and the oxidizing electrode 17, and the power generation efficiency can be improved.

The protruding portion 43 of the current collector 40 is in surface contact with the separator 21 to suppress a decrease in power generation efficiency due to a gap.

The convex shape of the current collector plate 40 has a step portion 44 provided on the surface on the side of the separator 21, and the step portion 44 has an edge portion of the fuel electrode 13 and the oxidation electrode 17 (edge portions 14c of the catalyst layers 14 and 18, By being arranged outside 18c), it is possible to secure a space in which the fuel gas and the oxidizing gas to be supplied to the inside and the fuel gas and the oxidizing gas to be discharged from the inside flow, and to suppress a decrease in pressure loss. be able to.

The insulating plate 50 has a first insulating plate body 51 and a second insulating plate body 52 into which the first insulating plate body 51 is fitted. In the second insulating plate body 52, the current collecting plate body 41 is on the separator 21 side. The first insulating plate body 51 has a bolt 53 that applies a pressing force to the separator 21 side, so that the first insulating plate body 51 pushes the collector plate 40 toward the separator 21 side. The power can be adjusted.

According to the fuel cell of the present invention, it is possible to apply a load evenly over the entire surface of the electrode and improve the degree of adhesion. Therefore, the fuel cell can be extremely usefully used in the cell industry and the like.

10 Cell 11 Solid Polymer Electrolyte Membrane 13 Fuel Electrode 14 Catalyst Layer 14c Edge 15 Gas Diffusion Layer 17 Oxidizing Electrode 18 Catalyst Layer 18c Edge 19 Gas Diffusion Layer 20 Cell Laminate 21 Separator 22 Coolant Gasket 40 Current Collector 41 Current Collector Plate body 41a Side surface portion 41b Side surface portion 41c Edge portion 42 Bus bar 43 Projection portion 44 Step portion 50 Insulating plate 51 First insulating plate body 51a Side surface portion 51b Side surface portion 51ga Recessed portion 51gb Liquid gasket groove 51k Bolt hole 52 Second insulating plate body 52a Side surface portion 52b Side surface portion 52e Opening portion 52f Recessed portion 52i Flange portion 52ha Fuel gas passage 52hb Oxidation gas passage 52hc Water passage 53 Bolt (pressing tool)
53a Head part 53b Shaft part 53ba Tip part 54 O-ring 60 End plate 60h Bolt hole 71 Bolt 72 Nut 100 Fuel cell main body

Claims (3)

A cell in which electrodes having a catalyst layer and a gas diffusion layer are arranged on both sides of the electrolyte membrane,
A plurality of the cells are stacked via a separator, a pair of current collectors arranged outside the plurality of stacked cells,
A pair of insulating plates arranged outside the pair of current collectors,
A pair of end plates arranged outside the pair of insulating plates,
A fuel cell comprising: fastening means for fastening the pair of end plates,
The current collector plate is formed in a convex shape so that a region where the gas diffusion layer of the electrode and the current collector plate face each other is thicker than a region where the gas diffusion layer of the electrode and the current collector plate do not face each other. It is,
The insulating plate has a first insulating plate that makes surface contact with the end plate, and a second insulating plate having a recess into which the first insulating plate fits.
The second insulating plate, the current collector plate has an opening that can be exposed to the separator side,
The fuel cell, wherein the first insulating plate has a pressing force applying means for applying a pressing force to the separator side . The fuel cell according to claim 1,
The fuel cell is characterized in that the current collector plate is in surface contact with the separator. In the fuel cell according to claim 1 or 2,
The convex shape of the current collector plate has a step portion provided on the surface on the separator side,
The fuel cell is characterized in that the step portion is disposed outside an edge portion of the electrode.

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