JP2022049240A - Fuel cell - Google Patents

Abstract

To provide a fuel cell that can make tightening surface pressure applied to a fuel cell laminate uniform, with size made more compact.SOLUTION: A fuel cell includes: a single cell battery laminate; current collector plates placed at both ends of the single cell battery laminate to extract electricity; insulating plates for electrical insulation placed on outer sides of the current collector plates; elastic bodies each placed between the current collector plate and the insulating plate to make tightening surface pressure uniform; external manifolds located respectively on side surfaces of the single cell laminate to supply fuel gas, oxidant gas, and cooling water; and fitting structure portions that each fit and fix the external manifold and the insulating plate. In the fitting structure portion, the external manifold is fixed to the insulating plate in a state in which the insulating plate is pressed in a direction for the external manifold and the insulating plate to approach to each other.SELECTED DRAWING: Figure 1

Description

Embodiments of the present invention relate to fuel cells.

Conventionally, a fuel cell having an external manifold for supplying cooling water, a fuel gas, and an oxidant gas to a single cell battery has been known. In addition, a single-cell battery laminate in which a plurality of single-cell batteries are laminated, a current collector arranged at both ends of the single-cell battery laminate for extracting electricity, and an electrically insulating plate arranged on the outside of the current collector plate. A fuel cell having a structure in which a fuel cell laminate composed of an insulating plate is fastened is known.

As a structure for fastening the fuel cell laminate having the above-mentioned single cell battery laminate, current collector plate, and insulating plate, a pair of end plates are arranged at both ends of the fuel cell laminate, and a plurality of end plates straddling these end plates. There is known a structure in which a tie rod is arranged and the tie rod is tightened with a nut. In a fuel cell having this structure, the pair of end plates are moved in a direction close to each other by moving the nut installed on the tie rod up and down, and the fuel cell laminate is tightened between the members constituting the fuel cell laminate. The contact electrical resistance is reduced.

Japanese Unexamined Patent Publication No. 2019-46540

In the conventional fuel cell described above, when the tightening pressure of the nut that tightens the fuel cell laminate is non-uniform, or when the nut becomes loose due to aging or vibration and the tightening pressure becomes non-uniform, etc., the end The plate is distorted. Due to this distortion, the tightening surface pressure of the end plate applied to the fuel cell laminate may become non-uniform.

In this way, if the tightening surface pressure of the end plate applied to the fuel cell laminate becomes non-uniform, the contact electrical resistance may increase due to insufficient surface pressure, or the fuel cell laminate may be damaged due to excessive surface pressure. There was a problem.

In addition, by using the end plate and tie rod in the structure for tightening the fuel cell laminate, the fuel cell becomes one size larger, and the volume occupied by the fuel cell in the fuel cell system becomes larger. Therefore, the fuel cell in the fuel cell system becomes larger. And the space for arranging each component is limited, and there is a problem that efficient component placement cannot be performed.

The present invention has been made to solve the above-mentioned conventional problems, and an object thereof is to provide a more compact fuel cell while being able to always make the tightening surface pressure applied to the fuel cell laminate uniform. There is something in it.

The fuel cell of the embodiment is a single-cell battery laminate in which a plurality of single-cell batteries are laminated, a current collector plate arranged at both ends of the single-cell battery laminate, and a current collector plate for extracting electricity, and outside the current collector plate. An insulating plate that is arranged and electrically insulated, an elastic body that is arranged between the current collector plate and the insulating plate and that makes the tightening surface pressure uniform, and an elastic body that is arranged on the side surface of the single cell laminated body. An external manifold for supplying fuel gas, oxidant gas, and cooling water, and a fitting structure portion for fitting and fixing the external manifold and the insulating plate are provided, and the external manifold is provided with the fitting structure portion. The manifold is fixed to the insulating plate in a state where the insulating plates are pressed in a direction close to each other.

The exploded perspective view which shows typically the structure of the fuel cell which concerns on embodiment. The figure which shows the state which fixed the insulating plate of the fuel cell of FIG. 1 and the external manifold.

Hereinafter, the fuel cell according to the embodiment will be described with reference to the drawings.

FIG. 1 is an exploded perspective view schematically showing the configuration of the fuel cell 100 according to the embodiment. In FIG. 1, a substantially square columnar single-cell battery laminate 101 in which a plurality of single-cell batteries are laminated utilizes, for example, an electrochemical reaction between a fuel gas containing hydrogen and an oxidant gas such as air containing oxygen. Generate electricity. In a single cell battery, for example, an electrolyte membrane / electrode assembly configured by arranging a fuel electrode and an oxidant electrode across an electrolyte membrane and a gas supply to the electrolyte membrane / electrode assembly and fuel and an oxidant are supplied. It has a separator having a function of separating.

A substantially square current collector plate 102 for extracting electricity from the single cell battery laminate 101 is installed at both ends of the single cell battery laminate 101, and a substantially square current collector plate 102 is installed on the outside of the current collector plate 102 from the current collector plate 102. A substantially square insulating plate 103 for electrically insulating is installed.

A substantially square elastic body 104 for adjusting the surface pressure applied to the single cell battery laminate 101 is installed between the current collector plate 102 and the insulating plate 103. The elastic body 104 is made of, for example, a rubber or metal spring body and is elastically deformable in the thickness direction thereof, so that the tightening surface pressure of the single cell battery laminate 101 and the current collector plate 102 can be made uniform. It acts as a rubber.

In the fuel cell 100 shown in FIG. 1, the case where the elastic bodies 104 are installed on both sides of the single cell battery laminate 101 is shown, but the elastic body 104 can be installed only on one side of the single cell battery laminate 101. I do not care. The insulating plate 103 and the elastic body 104 are provided with power outlets 103b and 104b for taking out the electric power generated by the single cell battery laminate 101 through the current collector plate 102.

External manifolds 105 for supplying fuel gas, oxidant gas, and cooling water to the single-cell battery laminate 101 are arranged on four side surfaces along the longitudinal direction of the single-cell battery laminate 101. Note that FIG. 1 shows only the two external manifolds 105 arranged on the two side surfaces of the single-cell battery laminate 101 located on the front side of the single-cell battery laminate 101 in the figure for the sake of clarity. be.

The external manifold 105 and the insulating plate 103 are provided with a fitting structure for fixing them. In the fuel cell 100 of the present embodiment, the fitting structure portion is composed of a convex portion 105a provided on the external manifold 105 described below and a concave portion 103a provided on the insulating plate 103. However, the fitting structure portion may have any structure as long as the external manifold 105 and the insulating plate 103 can be fixed by fitting. For example, a convex portion is provided on the insulating plate 103 side. A recess may be provided on the outer manifold 105 side. In the present embodiment, a case where a total of four external manifolds 105 are provided on four side surfaces of the single cell battery laminate 101 along the longitudinal direction will be described, but the case where the external manifolds 105 are provided with a total of four external manifolds 105 will be described. The plate 103 may be provided on at least two opposite side surfaces.

The upper end and the lower end (both end portions in the longitudinal direction) located on the single cell battery laminate 101 side of the outer manifold 105 have convex portions 105a protruding from the outer manifold 105 toward the upper side and the lower side, respectively. Is provided. As shown in FIG. 2, these convex portions 105a have a shape in which the lateral width gradually widens toward the direction (tip side) protruding from the external manifold 105, and the lateral end faces face the external manifold 105 side, respectively. It is a diagonal surface.

On the other hand, on the four side surfaces of the insulating plate 103 facing the outer manifold 105 side, recesses 103a having a shape corresponding to the convex portion 105a of the outer manifold 105 are provided. That is, as shown in FIG. 2, these recesses 103a have a shape that gradually widens from the outer manifold 105 side to the inner side (upper side or lower side).

The fitting structure is such that the convex portions 105a of the external manifold 105 can be fitted and fixed to the concave portions 103a of the insulating plate 103, respectively. When the convex portions 105a on both sides of the external manifold 105 are fitted into the concave portions 103a of the insulating plates 103 arranged on both sides of the single cell battery laminate 101, the insulation located at both ends of the single cell battery laminate 101 is provided. The insulating plate 103 is pressed in a direction close to each other to bring the insulating plate 103 close to each other, and the single cell battery laminate 101 is tightened (the elastic body 104 is compressed in the thickness direction and elastically deformed). The convex portion 105a provided on the outer manifold 105 is fitted into the concave portion 103a provided on the side surface of the 103.

Then, the external manifold 105 and the insulating plate 103 are fixed with a plurality of screws (4 in the example shown in FIG. 1 for each external manifold 105). FIG. 2 shows a state in which the convex portion 105a provided on the external manifold 105 is fitted into the concave portion 103a provided on the insulating plate 103, and the screw 106 is screwed in to fix the insulating plate 103 and the external manifold 105.

By fixing the external manifold 105 and the insulating plate 103 as described above, an elastic force that is compressed in the thickness direction and elastically deformed to extend in the thickness direction is applied to the recess 103a. The convex portion 105a and the convex portion 105a are fixed. That is, since the tip side of the convex portion 105a has a wider shape than the base end side, when a force is applied in the direction of extending up and down in FIG. 2, an oblique surface facing downward of the convex portion 105a and an oblique surface. The diagonal surface facing upward of the recess 103a is pressed and these are fixed.

As described above, in order to fix the external manifold 105 and the insulating plate 103 in a state where the elastic body 104 is compressed in the thickness direction and elastically deformed, the single cell battery laminate 101, the current collector plate 102, and the elastic body are used. It is necessary to set the dimensions in the longitudinal direction of the external manifold 105 so that the distance between the convex portions 105a at both ends of the external manifold 105 is shorter than the distance between the upper and lower concave portions 103a in the state where the 104 and the insulating plate 103 are laminated. There is. That is, it is designed so that the convex portion 105a can be fitted in the concave portion 103a while the insulating plates 103 on both sides are pressed and brought close to each other.

In this case, it is necessary to consider the dimensional tolerance between the design dimension and the actual dimension, and by setting a large thickness of the elastic body 104 and the length that can be elastically deformed, the dimensional tolerance is absorbed and the tightening pressure is applied. Can be constant and uniform. For example, when a dimensional tolerance of 1 is expected, the elastically deformable expansion and contraction length of the elastic body 104 is set to be larger than 1, for example, 2 or more, and 3 or more to absorb the dimensional tolerance and keep the tightening pressure constant and uniform. can do.

According to the fuel cell 100 of the present embodiment, the external manifold 105 is fixed to the insulating plate 103 in which the single cell battery laminate 101, the current collector plate 102, and the elastic body 104 are fastened, whereby the external manifold 105 is connected. The single cell battery laminate 101, the current collector plate 102, the insulating plate 103, and the elastic body 104 can be tightened with fixed dimensions, and the tightening pressure can be kept constant and uniform.

Further, even if the external manifold 105 has a dimensional tolerance, the elastic body 104 can expand and contract to keep the tightening surface pressure uniform. Further, since moving parts such as nuts are not required, it is possible to reduce the number of parts and reduce the problems caused by insufficient or excessive tightening pressure.

As described above, in the fuel cell 100 of the present embodiment, since the structure is such that the single cell battery laminate 101 is tightened by the external manifold 105 manufactured with the specified dimensions, the tightening pressure applied to the single cell battery laminate 101 is applied. Has the advantage of being always constant, uniform and invariant. In addition, since the fuel cell is compact because no end plate or tie rod is used for the tightening structure, the fuel cell and parts can be arranged more freely in the fuel cell system.

Although some embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

100 ... Fuel cell, 101 ... Single cell battery laminate, 102 ... Current collector plate, 103 ... Insulation plate, 103a ... Recess, 103b ... Power outlet, 104 ... Elastic body, 104b ... Power Take-out port, 105 ... External manifold, 105a ... Convex part, 106 ... Screw.

Claims (5)

A single-cell battery laminate in which multiple single-cell batteries are stacked, and
A current collector plate arranged at both ends of the single cell battery laminate and for extracting electricity,
An insulating plate arranged on the outside of the current collector plate for electrical insulation,
An elastic body arranged between the current collector plate and the insulating plate for making the tightening surface pressure uniform, and
An external manifold located on the side surface of the single cell laminate to supply fuel gas, oxidant gas and cooling water.
It is provided with a fitting structure for fitting and fixing the external manifold and the insulating plate.
A fuel cell characterized in that, in the fitting structure portion, the external manifold is fixed to the insulating plate in a state where the insulating plate is pressed in a direction close to each other. The fuel cell according to claim 1.
The single cell battery laminate has a substantially square columnar outer shape, and has a substantially square columnar shape.
A fuel cell characterized in that the fitting structure portion is provided so as to fit the external manifold and the insulating plate located on at least two facing surfaces of the single cell battery laminate. The fuel cell according to claim 1 or 2.
The fitting structure portion includes convex portions provided at both end portions of the external manifold and the protrusions.
A fuel cell provided on the insulating plate and having a concave portion that can be fitted to the convex portion. The fuel cell according to claim 3.
The convex portion has a shape that gradually widens from the external manifold side toward the tip side.
The fuel cell is characterized in that the recess has a shape that gradually widens from the external manifold side to the back side. The fuel cell according to any one of claims 1 to 4.
A fuel cell characterized in that the external manifold and the insulating plate are screwed together at the fitting structure portion.

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