JPH046261B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to an electrolyte circulation type stacked secondary battery.

B. Summary of the Invention The present invention provides sheet-like carbon fibers that are integrally molded on the electrode portion of a framed electrode to have a smaller area than the electrode portion, thereby preventing the sheet-like carbon fibers from protruding from the electrode portion and forming the electrode portion. An object of the present invention is to provide an electrolyte circulation type stacked secondary battery that is prevented from being pinched between the battery and the frame member.

C. Prior Art FIG. 1 is an exploded perspective view showing an example of an electrolyte circulating type stacked secondary battery having a bipolar stacked structure. This battery A has a plurality of stacked single cells a with separators 2 interposed between electrodes 1, sandwiched between end plates 3 on both sides, bolt through holes 11 provided in each member,
A bolt 4 is inserted through 12 and tightened to form the whole unit. A framed electrode 1 is used as a component of such a laminated secondary battery.

The framed electrode 1 is composed of an electrode part 12 and a frame part 13 provided on the outer periphery of the electrode part 12, and the frame part 13 has a manifold 14 and, if necessary, a microchannel 15 having a plurality of protrusions. Furthermore, a channel 16 that communicates the microchannel 15 and the manifold 14 is provided. In the framed electrode 1 in which the microchannel 15 is formed, the negative electrode (positive electrode) attached to the end plate 3
The electrolyte that enters the battery A from the electrolyte inlets 5 and 6 is introduced into the framed electrode 1 from the manifold 14, and then from the channel 16 to the microchannel 15.
After being guided by the flow, the flow is dispersed to the left and right, and the flow is uniformly branched to the electrode section 12. In addition,
The framed electrode 1 is point symmetrical, and when rotated by 180 degrees, it becomes the back side, and the opposite electrolyte flows in the same way as on the front side.

Further, in the framed electrode 1, the electrode part 12 is made of thermoplastic plastic mixed with a conductive substance such as carbon, while the frame part 13 is made of the same electrically insulating and impermeable material as the plastic. Become.

A method of manufacturing the framed electrode 1 will be explained below. Second
As shown in the figure, a frame member 13a made of thermoplastic plastic is placed around the outer periphery of a conductive electrode member 12a made of thermoplastic carbon plastic (the inside of the imaginary line in the electrode member 12a is the exposed electrode surface and the channel), and the frame auxiliary member 13b is superimposed on at least one surface thereof. Further, if necessary, thermoplastic microchannel members 15a are superimposed on both sides. Here, a sheet-like carbon fiber 6 such as carbon cloth is further stacked on the electrode portion 12 and formed into a whole band. This is because one side of the electrode part 12 is used as a positive electrode (bromine electrode) when the framed electrodes 1 are stacked, so by stacking sheet-like carbon fibers, the reaction surface area of the electrode part 12 is reduced by stacking carbon fibers only. This is to increase the amount by several times to several tens of times compared to .

D Problems to be Solved by the Invention Conventionally, each of the above-mentioned members was put into a mold to form a framed electrode 1.
When integrally molding the electrode member 12 by heat pressing, in order to secure the effective area of the electrode member 12,
As shown in FIG. 3, the electrode member 12a and the frame member 13a are separated by about 1.5 to 1.5 mm to prevent the melted frame member 13a etc. from flowing out onto the surface of the electrode member 12a and to make the boundary between the electrode part 12 and the frame part 13 straight. 2.0mm width slight gap 7
was opened and placed inside the mold.

On the other hand, the sheet-like carbon fiber 6 was cut to approximately the same size as the electrode member 12a, superimposed on the electrode member 12a, and integrally formed by heat pressing. Therefore, the carbon fibers 6 were elongated during the fusion process, protruded from the edge of the electrode member 12a, and were caught in the gap 7 between the frame member 13a and the electrode member 12a. This carbon fiber 6 does not contain polyolefin resin, such as polyethylene or polypropylene, which forms the matrix of the electrode member 12a and the frame member 13a, so it may cause poor fusion, cracks, or small cracks in the part of the molded product. There was a problem with cracks, etc.

The present invention has been made to solve the above problems.

E Means for Solving the Problems In the electrolyte circulation type stacked secondary battery according to the present invention,
A rectangular electrode part, a synthetic resin insulating frame provided around at least one surface of the electrode part, and a pair of electrolyte current passages provided respectively on a pair of opposing sides of the insulating frame. A plurality of framed electrodes are stacked, and a battery reaction chamber surrounded by the electrode part and the insulating frame is formed by the stacking,
In the electrolyte circulation type stacked secondary battery configured to allow electrolyte to flow in and out from the flow path into the battery reaction chamber, a sheet-like carbon fiber having a smaller area than the electrode portion of the framed electrode is disposed on the electrode portion. It is formed in one piece.

F Function In the present invention, since the sheet-like carbon fibers having a smaller area than the electrode part of the framed electrode are integrally formed on the electrode part, the sheet-like carbon fibers protrude from the electrode part and become part of the electrode part. An electrolyte circulation type stacked secondary battery that is not sandwiched between the frame member and the frame member can be obtained.

G Embodiment FIG. 4 is a sectional view showing the structure of a framed electrode of an electrolyte circulation type stacked secondary battery according to an embodiment of the present invention. In the figure, the frame electrode is produced by placing a frame member 13a around the outer periphery of the electrode member 12a, placing a carbon cloth 6 cut into a size approximately A smaller in circumference than the electrode member 12a on top of the electrode member 12a, and using a heat press method. It is integrally molded by. In this example, the carbon cloth did not protrude and get caught in the gap between the electrode member 12a and the frame member 13a.

It has been found that A is preferably 2 to 10 mm. This is such a cutting allowance that the reduction in the intended reaction area can be ignored, and is such that even if it expands when pressurized by mold clamping, it will hardly protrude beyond the electrode member 12a. On the condition that the effective electrode area is approximately 300 to 1000 ports,
The thickness was experimentally determined in the range of 0.5 to 1.5t, and the thickness of the electrode frame 13 was in the range of 0.9 to 4.5t.

H Effects of the Invention As explained above, the present invention is formed by integrally forming a sheet-like carbon fiber having a smaller area than the electrode part of the framed electrode on the electrode part. It does not protrude from the electrode portion and become sandwiched between the electrode portion and the frame member. Therefore, the electrolyte circulation type laminated double layer does not cause cracks, cracks, poor fusion, etc. between the frame part and the electrode part due to the sandwiching of carbon fibers, and the intended reaction surface area of the electrode is hardly impaired. A second battery is obtained. As a result, there is also the effect that the yield of molded products is significantly improved.

[Brief explanation of drawings]

Figure 1 is an exploded perspective view of an electrolyte circulation type stacked secondary battery, Figure 2 is an explanatory diagram showing a conventional method for forming a frame electrode, and Figure 3 is a conventional electrolyte circulation type stacked secondary battery. FIG. 4 is a vertical cross-sectional view of the main part of the framed electrode of the electrolyte circulation type stacked secondary battery according to the embodiment of the present invention. DESCRIPTION OF SYMBOLS 12... Electrode part, 13... Frame part, 12a... Electrode member, 13a... Frame member, 6... Sheet-like carbon fiber, 7... Gap.

Claims (1)

[Scope of Claims] 1. A rectangular electrode part, a synthetic resin insulating frame provided around at least one surface of the electrode part, and a synthetic resin insulating frame provided on a pair of opposing sides of the insulating frame, respectively. A plurality of framed electrodes each having a pair of electrolyte current passages are stacked, and a battery reaction chamber surrounded by the electrode part and the insulating frame is formed by stacking the frame electrodes, and the battery reaction chamber is surrounded by the electrode part and the insulating frame. In an electrolyte circulation type stacked secondary battery configured to allow electrolyte to flow in and out from a flow path, a sheet-like carbon fiber having a smaller area than the electrode portion of the framed electrode is integrally formed on the electrode portion. An electrolyte circulation type laminated secondary battery characterized by the following.