JPS58164154A - Electrolyte impregnating method of fuel cell - Google Patents

Abstract

PURPOSE:To impregnate the electrolyte fully into a matrix by degassing a fuel cell fully at a high temperature then feeding the electrolyte and maintaining the condition for a long time. CONSTITUTION:A fuel cell block 8 laminated with a plurality of unit cells is installed in a vacuum heating furnace 9 horizontally or at a slight inclination. The block 8 is heated to 70-120 deg.C under this condition, then the vacuum heating furnace 9 is degassed fully to the degree of vacuum of 5mm. Hg or less. This condition is maintained for a fixed time, then the electrolyte 11 heated to 70- 120 deg.C and vacuum degassed is gradually fed into the block 8 from an external heating tank 10 so as to fill the block 8 fully. Next, the atmosphere in the vacuum heating furnace is maintained at a vacuum and high temperature under the condition that the electrolyte is held in the block 8. Then, a valve 13 is opened under the condition that the atmosphere in the vacuum heating furnace 9 is kept at a vacuum and high temperature, and the electrolyte being held in the block 8 is discharged to an external tank 14 with the same degree of vacuum as that of the vacuum heating furnace 9. After the electrolyte has been fully discharged, the dry air is fed through a valve 15 so as to attain a normal pressure condition.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for impregnating an electrolyte into a fixed electrolyte fuel cell matrix. When the matrix of a fuel cell is impregnated with an electrolyte, it is necessary to fill the voids in the matrix with the electrolyte to prevent mixing of fuel and air. Electric,
The ponds are layered. In other words, the unit cell of the fuel turtle includes an anode 11, a cathode 3, a non-conductive and porous member (matrix) 2 sandwiched between both electrodes, and a separator plate 4 that prevents current collection and gas mixing. It has a structure in which these are layered in the vague order shown in the diagram. Second enlarged view of the reef
As shown in the figure.

Both the 7 node @l and the canode s3 have a structure in which a catalyst layer 7 consisting of a carbon sym wheel carrying a platinum catalyst is coated and laminated using carbon #16 made of paper-like carbon fibers as a base material, and the matrix 2 The powder has a particle size of approximately 5 tones.

When the matrix 2 is impregnated with a phosphoric acid electrolyte as an electrolyte, there are the following problems. Namely, the fuel cell stain is usually used with a high #I storm, and the viscosity is extremely high.

Figure II3 shows the relationship between the temperature of phosphoric acid in the device 10G, and due to its high viscosity, the electric S*fr! The capillary effect for impregnating the matrix is low, and the penetration of the electrolyte into the interior of the matrix is falsely slow. In addition, because the electrolyte has a high viscosity, the gas in the electrolyte is difficult to release to the outside.◎-The particle shape of the material that makes up the matrix is not uniform, and the electrolyte is not impregnated at a uniform rate. Therefore, bubbles tend to form in shallow areas within the matrix.

As described above, it is difficult to impregnate the matrix with a necessary and sufficient amount of S-sodium, leading to problems such as mixing of fuel and air and poor characteristics of the fuel cell.

The purpose of this book is to provide a successful impregnation method in view of the nature of regional dissolution and rinsing. In addition to increasing the capillary effect for the fuel cells, we have established a method of removing the matrix and the molten reeds and impregnating the predetermined locations with the electrolytic gas of bubbles, which is effective in maintaining the stability of the output characteristics of the fuel cell. This is what you get.

FIG. 4 shows an embodiment of the invention.

A fuel cell block 8 in which a plurality of unit cells are stacked as shown in FIG. 1 is installed in a vacuum heating furnace 9 horizontally or with a slight inclination. In this state, block 8 was heated to 41°C at 70 to 120°C.
After raising the temperature to i-, the vacuum heating furnace 9 is heated to a sufficient degree of vacuum (5
- Hf or less). After maintaining this state for a certain period of time, the external heating tank 10 heated the IEOCK bowl to 70°C, and the temperature reached 70°C. The degassed electric S trace 11 is introduced into a vacuum heating furnace 9 through the pulp 12 and gradually supplied into the boot stock 8. eg
The supply of cl[ is stopped when the pulp 13 is closed in the area where the boot stock 8 is sufficiently filled with electricity S*. In this case, while maintaining the 'III residual in the block 8, the
The temperature is maintained at the threshold of 2 to 10 o'clock. After that, the vacuum heating furnace 9
5 to 1 t of vacuum inside and 10 to 120℃
The pulp 13 is opened in a state where the atmosphere is kept at a temperature of ! ! It is discharged into an external tank 14 which has the same degree of vacuum as the temperature.

After sufficiently discharging the electrolyte, dry gas is supplied from the pulp 1B to the inside of the vacuum m-heating device 9 to create a normal pressure state.This completes the operation of impregnating the fuel cell with the electrolyte under vacuum conditions. - As described above, according to the present invention, the fuel cell is fully degassed at 4 temperatures (70 to 120 degrees Celsius).
Since the shape is maintained for a long period of time, it only takes 9 minutes to fully impregnate the matrix with 5 tft of electricity.

[Brief explanation of the drawing]

The lI1 diagram is an 11m diagram of the single cell, the 2nd garden is an enlarged view of the side of the electric reef, and the gal is lIJ[1G (HI glue/acid (D glue)
The l law diagram and lI4 diagram are of the present invention! lI example a*v! i7
! , is an illustration. 8...Fuel cell block, 9...Vacuum heating furnace, 11
... Electrolyte. f 3 mouths/4 1'4 mouths

Claims (1)

[Claims] In a fuel cell that has a single cell in which an electrode lix is sandwiched between electrodes, a high temperature electrolyte is supplied to a matrix of fuel 'tI/La in a vacuum heating furnace under a sufficient degree of vacuum. A method for impregnating an electrolyte in a fuel cell, which further comprises impregnating a matrix with an electrolyte at a high temperature and under a sufficient degree of vacuum.