JPH02148580A - Electrolyte circulation type stacked battery - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application This invention relates to a stacked battery that is used while circulating an electrolyte.

B9 Summary of the Invention The present invention provides a stacked battery in which an electrolyte is used while circulating, in which a member including a frame that constitutes a stack of battery bodies has a melt flow index of 10 or more. 30wt% or more of glass fiber in high-pressure polyethylene
By using insert injection molding to integrally form the frame using a material containing 50 wt% additive, the member that includes the frame is formed flat, allowing for good stacking. .

C0 Conventional Technology Recently, the development of battery power storage systems has been promoted.
As a part of this, an electrolyte circulation type zinc-bromine laminated secondary battery as illustrated in FIGS. 2 and 3 has been developed.

As shown in the structural principle diagram in Fig. 2, this
is divided into an anode chamber 3 and a cathode chamber 4 by a separator 2 made of an ion exchange membrane or a porous membrane, and liquid sending tubes 5, 6 and liquid return tubes 7, 8 are used to circulate the electrolyte to these two electrode chambers, respectively.
Electrolyte tanks 9 and 10 connected to each other are provided to circulate an electrolyte of zinc bromide (ZnBr) to each electrode chamber. In addition, 11 is an anode, 12 is a cathode, 13 and 14 are both liquid feeding pumps, and 15 is a valve.

Thus, during charging, the electrolyte circulates in the direction of the arrow in the figure, and at the cathode 12 Z n ''+2 cm → Zn.

At the anode 11, a reaction of 2Br-->Br"+2e occurs, and the bromine produced at the anode 11 becomes molecules, mixes in the electrolyte, partially dissolves, and mostly forms complexes with the complexing agent in the anolyte. is precipitated and accumulated in the electrolyte tank 10 on the anode chamber side.In addition, during discharge, a reaction opposite to the above reaction formula occurs at each electrode 11, 12 with the electrolyte circulating, and the precipitate (Zn, Br,) is for each electrode 11
．． 12 and is consumed (oxidized, reduced) to release electrical energy.

Further, in the zinc-bromine battery having the above-mentioned construction principle, a stack of a large number of cell laminated structures is used as a practical laminated battery body as illustrated in FIG. This includes a pair of tightening end plates 16 for holding the entire stack by fitting nuts 29 into a plurality of bolts 28 that penetrate from one side to the other side so as to sandwich the entire stack. For example, 30 cells are stacked in between.

That is, a separator is formed by insert injection molding a polyolefin-based crystalline resin around the outer periphery of a microporous membrane to form a frame body next to the end plate electrode 18 having one carbon plastic current collecting mesh. A frame is formed by stacking the plates 21 and insert injection molding a polyolefin crystalline resin around the outer periphery of a carbon plastic electrode plate made of polyethylene or polypropylene kneaded with carbon black and, if necessary, graphite. The flat plate intermediate electrodes 23 are stacked, and finally the other carbon plastic end plate electrode 18 is stacked, making a total of 3 layers.
The structure is such that 0 cells are stacked.

Next, each bolt 28 is inserted into each through hole 27 that is bored at a predetermined position near the periphery of each tightening end plate 16.
The nut 29 is screwed together, and the entire stack is sandwiched and the gasket 20 is crimped and tightened to prevent liquid leakage.

As shown in Fig. 3, this stack has positive electrode manifolds 2, which are liquid flow holes, at its four corners.
4 and the negative electrode manifold 25 are bored.

Furthermore, each separator plate 21 has microchannels 26 installed in a symmetrical shape on both sides of the frame body 21a, which also functions as a gasket, on the upper and lower sides of the frame body 21a. The electrolytic solution introduced from the positive electrode manifolds 24 on the diagonal lines is spread uniformly and flowed over the entire surface of the separator 2, or the solution is collected from this. Further, a microchannel 26 shown by a broken line on the other side is for introducing and recovering the electrolytic solution from the negative electrode manifold 25.

In this way, between the electrodes arranged on both side surfaces of each separator plate 21, cells that become the unit battery illustrated in FIG. 2 are constructed, and 30 of these cells are connected in series to form a stack. It is configured so that

D2 Problems to be Solved by the Invention In the conventional stack constituting the battery body as described above,
Separator plate 21 or intermediate electrode 2 as the laminate
When insert injection molding the frame body No. 3, the molding shrinkage of the polyolefin resin used as the material is about 1 to 3%, so warpage occurs as shown in FIG.

In addition, to prevent this, as a filler (additive),
In some cases, 4Qwt% of glass fiber is added, but in this case, even if warpage due to molding shrinkage can be eliminated, the resin flowing from each gate 30 during injection molding may collide with each other, as illustrated in FIG. At the weld line 31, which is the area to be fused, the direction of the glass fiber as a filler becomes random, resulting in deformation of that area.

In this way, if the separator plate 21 and the intermediate electrode 23 are warped or deformed, a gap will be created between them when they are stacked, and in order to eliminate this, the tightening end plates 16 at both ends are
It is necessary to increase the tightening force of the bolt 28 that tightens the space between the
There was a problem in that it required time and effort to manufacture.

Furthermore, warping and deformation can cause electrolyte to leak between them, leading to short circuits and corrosion, which can shorten the life of the battery. there were.

In view of the above-mentioned points, the present invention is made by injection molding frames such as separator plates and intermediate electrodes to form them in a flat plane, so that the bolt tightening force for stack fixing is not increased more than necessary. The purpose of the present invention is to make the battery easier and faster to manufacture, prevent leakage, and extend battery life.

E4 Means for Solving Problems The electrolyte circulation type laminated battery of the present invention is made by melt-melting the member comprising the frame that constitutes the laminate of the stack of battery bodies.
It is characterized in that the frame is integrally formed by insert injection molding using high-pressure polyethylene with a flow index of IOO12 to which 30wt% to 50W1% of glass fiber is added.

By configuring as described in F1 action, when insert injection molding the frame, it is possible to prevent warping due to molding shrinkage, and prevent deformation at the weld line.
This has the effect of making it possible to obtain a flat member.

G. Example Hereinafter, an example of the electrolyte circulation type stacked battery of the present invention will be explained with reference to FIG. In this FIG. 1, the same reference numerals are given to the parts corresponding to the conventional example shown in FIGS. 2 to 5 described above, and detailed explanation thereof will be omitted.

FIG. 1 shows an electrode plate 23, which is one of the members formed by insert injection molding of a frame, which is used to construct a stack of batteries in a laminated manner.

The frame 23a of the electrode plate 23 is made of high-pressure polyethylene (melt flow index of 10 or more, preferably 20 or more) as a molding resin, and 30wt of glass fiber is used to suppress molding shrinkage. %～50
Use wt% added.

Specifically, Showa Denko's Showa Rex M221. Melt flow index value 20. Asahi Fiber Co., Ltd. glass fiber 4
A frame body was integrally formed with the electrode plate material by insert injection molding using the material containing 0 wt%. This results in
As shown in FIG. 1, a flat electrode plate 23 without warping or deformation could be obtained.

H6 Effects of the Invention As detailed above, according to the electrolyte circulation type laminated battery of the present invention, the member including the frame that constitutes the laminate of the stack of battery bodies has a melt flow index. 3 glass fibers are added to high-pressure polyethylene with a temperature of 10 or more.
The frame body is integrally formed by insert injection molding using a material containing 0wt% to 50wt%, which prevents warping due to molding shrinkage and prevents deformation at the weld line, resulting in a flat surface. This has the effect that it is possible to obtain a member with a high quality.

Moreover, such a planar member has the effect of facilitating and speeding up the lamination work for producing a stack thereof.

Furthermore, it is possible to prevent electrolyte leakage from gaps between parts due to warping or deformation, and it is possible to avoid undue tightening force when tightening this laminate with bolts, thereby preventing unevenness. This has the effect of preventing stress from occurring, improving the reliability of the battery, and extending its service life.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of the main parts of an embodiment of the electrolyte circulation type stacked battery of the present invention, Fig. 2 is a diagram schematically explaining the principle of a conventional zinc-bromine battery, and Fig. 3 is the main parts thereof. FIGS. 4 and 5 are respectively perspective views of essential parts of the battery. DESCRIPTION OF SYMBOLS 1...Battery main body, 16...Tightening end plate, 21...Separator plate, 23...Intermediate electrode. Figure 1 Perspective view of main parts Figure 2 Schematic explanatory diagram Figure 3 Disassembled perspective view of main parts Perspective view of main parts Perspective view of main parts

Claims (1)

[Claims] (1) The member comprising the frame that constitutes the laminate of the stack of battery bodies is made of high-pressure polyethylene with a melt flow index of 10 or more and 30 wt% to 50 wt% of glass fiber.
An electrolyte circulation type stacked battery, characterized in that the frame is integrally formed by insert injection molding using the additive as a material.