JPH0145096Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a stacked fuel cell, and particularly relates to an electrolyte supply mechanism.

[Prior art]

Conventional stacked fuel cells have a mechanism for supplying and holding an electrolyte as shown in FIGS. 1 to 5.

FIG. 1 is a partially cutaway perspective view showing the inside of a stacked fuel cell to which this invention is applied, and FIGS. 2 and 3 are the - line and - line in FIG. 1, respectively.
4 and 5 are cross-sectional views showing an example of an electrolyte supply mechanism in the conventional stacked fuel cell shown in FIG. 1, respectively. In the figure, 1 is an electrolyte matrix, 2 and 3 are a fuel electrode and an oxidizer electrode that face each other with the electrolyte matrix 1 in between.
2 and 3 constitute a cell. 4 is a sealing gasket, and 5 is a gas separation plate, and a plurality of unit cells and gas separation plates 5 are alternately stacked to obtain a battery stack. 6,
7 is a gas passage provided in the gas separation plate 5 and supplies fuel and oxidant gas to the fuel and oxidizer electrodes 2 and 3, respectively; 8 is an electrolyte supply hole; 9 is a reinforcing plate; 10 is a gas passage provided in the gas separation plate 5. a reservoir provided and supplying an electrolyte to the electrolyte matrix 1;
Each reservoir 10 communicates with the electrolyte supply hole 8 . Reference numeral 11 denotes an electrolytic solution holding material filled in the reservoir 10, which communicates the peripheral edge of the electrolyte matrix 1 with the electrolytic solution holding material 11, and allows the electrolytic solution permeated into the electrolytic solution holding material 11 from this communicating portion to be transferred to the electrolyte matrix 1. supply to. Reference numeral 12 denotes a cooling plate that is inserted every several cells in order to keep the temperature of the battery constant, and the cooling plates 12 to 12 constitute one block of the battery stack. Reference numeral 13 indicates a solution supply port for supplying electrolyte from the outside to the electrolyte solution supply hole 8. Reference numeral 14 indicates a solution supply port 8 for the purpose of confirming that the electrolyte has been supplied to all the reservoirs 10 in the block, and for supplying the electrolyte solution to the electrolyte solution supply hole 8 when supplying the electrolyte. This is an overflow port that also serves as a vent for air mixed in the reservoir 10. Reference numeral 15 denotes a drain port for draining the electrolyte accumulated in the electrolyte supply hole 8 after the supply of the electrolyte is completed. 4 shows a structure in which the electrolyte is supplied from the top of the block, and FIG. 5 shows a structure in which the electrolyte is supplied from the bottom. Such a device is described, for example, in JP-A-58-10373 (58.1.20) ``Fluid Replacement Device for Matrix Type Fuel Cell''.

Next, a method of supplying electrolyte solution to each electrolyte matrix 1 will be explained with reference to FIGS. 1 to 5. In order to supply electrolyte to each electrolyte matrix 1, first, the electrolyte is supplied from the solution supply port 13 to the reservoir 10 through the electrolyte supply hole 8. The electrolytic solution supplied to the reservoir 10 permeates into the electrolytic solution holding material 11, and the fuel electrode 2 communicates with the electrolytic solution holding material 11.
It penetrates into the electrolyte matrix 1 integrally formed on the upper surface of the fuel electrode 2 from the peripheral edge of the fuel electrode 2 . After the electrolytic solution overflows from the overflow port 14 and the supply of electrolytic solution is completed, each unit cell is communicated with the electrolytic solution while the electrolytic solution is accumulated in the electrolytic solution supply hole 8 that communicates between each reservoir 10. This causes voltage loss due to leakage current, so the electrolyte in the electrolyte supply hole 8 is drawn out from the drain port 15 and blocked. Note that the arrows in each figure indicate the direction in which the electrolytic solution flows.

The conventional stacked fuel cell is constructed as described above, and each reservoir 10 is filled with the electrolyte holding material 11, so that the electrolyte supplied from the liquid supply port 13 does not flow within the reservoir 10. The path resistance was large, and it took a long time to reach the overflow port 14 from the liquid supply port 13, and it took a long time to supply the electrolytic solution to each block. Particularly, in the case of the structure shown in FIG. 5, it takes a long time for the electrolytic solution to reach the upper cell, which has the disadvantage that the battery characteristics deteriorate during that time.

[Summary of the idea]

This idea was made in order to eliminate the drawbacks of the conventional ones as described above, and a groove extending in the longitudinal direction is provided at the bottom of the reservoir to ensure a passage for the electrolyte to flow in the longitudinal direction of the reservoir. Accordingly, it is an object of the present invention to provide a stacked fuel cell in which the electrolyte passage can be ensured without reducing the planar area of the reservoir and the electrolyte supply time can be shortened.

[Example of idea]

An embodiment of this invention will be described below with reference to the drawings.

FIG. 6 is an exploded perspective view of a part of the gas separation plate according to an embodiment of the invention, and FIGS. 7 and 8 are taken by the - line and - line of the gas separation plate shown in FIG. 6, respectively. FIG. In the figure, 1
6 is a groove provided at the bottom of the reservoir 10 and extending in the longitudinal direction.

Next, a method of supplying electrolyte solution to each electrolyte matrix 1 will be explained. The electrolytic solution supplied from the liquid supply port 13 shown in FIGS. 4 and 5 reaches the groove 16 of each reservoir 10 through the electrolytic solution supply hole 8. Since the electrolytic solution has no flow resistance, after filling the groove 16 in a short time, the electrolyte holding material 1 located above the groove 16
Penetrate into 1. In this case, the electrolyte permeates from the entire lower surface of the electrolyte holding material 11 in the longitudinal direction at the same time, so that the permeation speed is extremely high. The infiltration of the electrolyte from the electrolyte holding material 11 into the electrolyte matrix 1 and the operation of the overflow port 14 and drain port 15 are the same as in the prior art.

In this way, since the passage or groove 16 through which the electrolytic solution flows is secured in the longitudinal direction of the reservoir 10,
Unlike in the past, when the electrolyte passes through the reservoir 10, it is not subjected to resistance by the electrolyte holding material 11, and the electrolyte can be easily supplied (including replenishment) to each electrolyte matrix 1 in a short time. ) can be performed.

Further, since the groove 16 is provided at the bottom of the reservoir 10, the planar area of the reservoir 10 and the planar area of the electrodes are not reduced.

[Effect of idea]

As described above, according to this invention, a groove extending in the longitudinal direction is provided at the bottom of the reservoir to ensure a passage for the electrolyte to flow in the longitudinal direction of the reservoir, thereby reducing the planar area of the reservoir. In this case, the electrolyte passage can be ensured without reducing the planar area of the electrode, and the electrolyte supply time can be shortened.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway perspective view of a conventional stacked fuel cell, FIGS. 2 and 3 are sectional views taken along lines - and - in FIG. 1, respectively, and FIGS. 4 and 5. 1 is a sectional view showing an example of an electrolyte supply mechanism in a conventional stacked fuel cell shown in FIG. 1, and FIG. 6 is a partially exploded perspective view showing a gas separation plate according to an embodiment of the invention. , 7th
8 and 8 are cross-sectional views taken along the - line and - line, respectively, of the gas separation plate according to an embodiment of the invention shown in FIG. 6. In the figure, 1 is an electrolyte matrix, 2 is a fuel electrode, 3 is an oxidizer electrode, 5 is a gas separation plate, 6,
7 is a fuel and oxidant gas passage, 8 is an electrolyte supply hole, 10 is a reservoir, 11 is an electrolyte holding material, 13
is the liquid supply port, 14 is the liquid overflow port, 15 is the exhaust port, 16
is a groove. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A unit cell having a fuel electrode and an oxidizer electrode facing each other with an electrolyte matrix interposed therebetween, and a gas separation plate having a gas passage supplying a reaction gas to each of the electrodes and a reservoir supplying an electrolyte to the electrolyte matrix are alternately arranged. In a stacked fuel cell in which a plurality of the above-mentioned reservoirs are stacked together, each of the above-mentioned reservoirs is communicated through an electrolyte supply hole, and the electrolyte is permeated into the electrolyte-retaining material filled in each of the above-mentioned reservoirs, the electrolyte is distributed in the longitudinal direction of the above-mentioned reservoirs. To ensure a route for distribution,
A stacked fuel cell characterized in that a groove extending in the longitudinal direction is provided at the bottom of the reservoir.