JPH0131666B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention relates to a framed electrode used in an electrolyte circulation type battery such as a metal (for example, Zn)-halogen (for example, Br) battery.

B: Summary of the Invention The present invention provides a framed electrode in which a conductive plastic electrode plate is surrounded by an insulating frame to form a battery reaction chamber on the electrode plate surface, and an inner resin insulating frame member in contact with the electrode plate; This is a framed electrode with little warpage, which is provided with an insulating frame having an integrated laminated structure of a glass wool frame member in the middle and an outer resin insulating frame member on the outer surface.

C. Prior Art FIG. 1 is an explanatory diagram of the principle of an electrolyte circulation type battery. This battery has electrodes 1 and 3 arranged on both sides with a separator 5 in between to form a unit cell. In addition, in FIG. 1, electrode 1 is a negative electrode, and electrode 3 is a positive electrode. Then, the negative electrode liquid is supplied from the negative electrode liquid storage tank 6 to the battery reaction chamber (negative electrode chamber) 2 between the electrode 1 (negative electrode) and the separator 5 and circulated.
The positive electrode solution is supplied from a positive electrode storage tank 7 to a battery reaction chamber (positive electrode chamber) 4 between the positive electrode (positive electrode) and the separator 5 and is circulated therein. Note that 9a and 9b are pumps for liquid circulation, and 10a and 10b are valves.

FIG. 2 is an exploded perspective view of the case where a required electrolyte circulation type battery is constructed by stacking a large number of unit cells each consisting of an electrode and a separator as shown in FIG.

In this figure, 11 is an aluminum fastening end plate, 12 is a resin fastening end plate, 13 is a packing, 1
4 is an electrode end plate, and 15 is a terminal made of wire mesh or the like.

Then, the battery is constructed by stacking electrodes 1 and separators 5 alternately, and clamping end plates are placed on both sides in the stacking direction.
1 are arranged and the whole is tightened with bolts 16 and nuts 17.

This type of electrode 1 is integrally equipped with an insulating frame around the electrode plate, and the middle part in the thickness direction of the insulating frame is formed so as to form battery reaction chambers (positive electrode chamber, negative electrode chamber) on both sides of the electrode plate. An electrode plate is provided to constitute a so-called framed electrode.

Further, this insulating frame is provided with a manifold 18 through which an electrolytic solution flows, and a flow path 20 that communicates between this manifold 18 and the battery reaction chamber. This flow path 20 is formed by a channel 19a and a microchannel 19b.

Incidentally, since the insulating frame of the electrode is required to have insulating properties and chemical resistance, this frame is made of polyolefin-based synthetic resin (for example, polyethylene).

On the other hand, the electrode plate is made of a conductive resin (for example, carbon plastic) having a base polymer of polyolefin resin (for example, polyethylene).

In order to integrate such an electrode plate and an insulating frame, frame members formed in the shape of a frame are placed on both sides of a rectangular electrode plate, and the two are placed one on top of the other and inserted into a mold.
This is done using a heat press method in which molding is carried out under heat and pressure within a mold.

On the other hand, the electrolytic solution (for example, positive electrode solution) is applied to the clamping end plate 1
1. The manifold 18 that passes through the insulating frame of the electrode 1 and the frame of the separator 5 in the stacking direction is passed through the channel 19a of the flow path 20 provided on one side of the frame of each electrode 1. The current is guided into the chamber (positive electrode chamber), further rectified by the microchannel 19b on one side of the insulating frame, and flows along the front surface of the electrode plate.

The electrolytic solution that has flowed along the electrode plate in the battery reaction chamber of each electrode is transferred to other electrodes via flow paths (microchannels and channels, not shown) formed on the other side of the insulating frame of the electrode. It is guided to the manifold and refluxed to the positive electrode electrolyte tank (see reference numeral 7 in FIG. 1).

Note that the negative electrode liquid flows to the battery reaction chamber formed on the other side of the electrode plate of each electrode through a flow route different from that of the positive electrode liquid, but the flow path configuration is different from that of the positive electrode. Since this is the same as in the case of liquid, its explanation will be omitted.

D Problems to be Solved by the Invention Now, in the conventional framed electrode constructed as described above, the insulating frame integrally molded with the electrode plate has a coefficient of linear expansion nearly twice as large as that of the electrode plate. Therefore, there was a problem that some warpage inevitably remained after integral molding.

Conventionally, in order to solve such problems,
It is necessary to select an insulating frame member whose coefficient of linear expansion is equal to that of both members constituting the insulating frame and the electrode plate, or whose coefficient of linear expansion is to some extent smaller than that of the electrode plate. Therefore, methods such as selecting the thickness ratio of each component of the framed electrode to a certain ratio and combining them in a certain order, or using a resin with a high molecular weight and density for the insulating frame, etc. Methods have been considered to select the physical properties of the elements themselves, but
It has been extremely difficult to select a material that satisfies both the problems of fusion bonding between the insulating frame and the electrode plate and securing an effective electrode surface due to limitations such as corrosion resistance to electrolyte and electrical properties.

The present invention has been made to solve the above problems, and by reducing the apparent coefficient of linear expansion of the insulating frame and the electrode plate, warping of the framed electrode caused by the shape of the component, etc. The purpose of this is to eliminate molding abnormalities caused by mechanical distortion, resin sink marks, and outflow.

E Means for Solving the Problems In order to achieve the above-mentioned object, the present invention provides a framed electrode in which a conductive plastic electrode plate is surrounded by an insulating frame member to form a battery reaction chamber on the surface of the electrode plate. , the insulating frame member is constituted by a laminated and integrated structure of an inner resin insulating frame member in contact with the electrode plate, an intermediate glass wool frame member, and an outer resin insulating frame member on the outer surface.

In the present invention, the thickness of the glass wool frame material is preferably 1.0 to 2.0 times the thickness of the electrode plate, and the total thickness of the inner resin insulation frame member and the outer resin insulation frame member is, for example, the thickness of the glass wool frame material. It is preferably 1.3 to 1.4 times the thickness. In addition, the thickness of the inner resin insulation frame member is 0.3±0.1 of the thickness of the glass wool frame material.
In contrast, the thickness of the outer resin insulating frame member is preferably 1.0 to 0.8 times the thickness of the glass wool frame member.

F Function In the framed electrode of the present invention, the insulating frame, which has a structure in which the glass wool frame material is sandwiched between the outer resin insulating frame member and the inner resin insulating material, is laminated and integrated with the electrode plate, so that the glass wool frame material is insulated. As the core material of the entire frame, it prevents thermal deformation of the insulating frame members and prevents warping, suppresses distortion and local resin sinks, and absorbs excess resin to prevent resin from seeping out onto the effective electrode surface. Since the inner resin insulating frame member is in contact with the electrode plate surface, the fusion bond between the two is also good.

G. Embodiments Examples of the present invention will be described below with reference to the drawings.

FIG. 3 is an explanatory diagram showing the constituent parts of a framed electrode according to an embodiment of the present invention. This framed electrode 50
A frame-shaped inner resin insulating frame member 60a having a predetermined uniform thickness is provided on both sides of a conductive plastic electrode plate (for example, carbon plastic) 70, and a predetermined uniform resin insulating frame member 60a having the same frame shape as this inner resin insulating frame member 60a. a thick sheet-shaped glass wool frame material 12;
The frame-shaped outer resin insulating frame member 60b, which also serves as a forming frame for the microchannel 19b (FIG. 2), is laminated in order, and these are simultaneously heated and pressurized in a mold to integrally mold the insulating frame. A glass wool filler mixed layer is integrally formed inside. This brings the coefficient of linear expansion of the insulating frame 60 close to that of the electrode plate 70, thereby eliminating warpage after molding.

In this embodiment, the thickness of each of the electrode plate 70, the inner resin insulating frame member 60a, the outer resin insulating frame member 60b, and the glass wool frame member 12 is set as follows, assuming that the thickness of the electrode plate 70 is 1. The thickness of the inner resin insulation frame member 60a is 0.3, the thickness of the sheet glass wool frame member 12 is 1, and the outer resin insulation frame member 6.
The thickness of 0b is set as a ratio of 1.

It is appropriate that the thickness of the glass wool frame material 12 be 1.0 to 2.0 times the thickness of the electrode plate 70.

In the case of the above embodiment, the ratio of the total thickness of the inner and outer resin insulating frame members 60a, 60b is 1.3, which is greater than the thickness of the glass wool frame material.
Most preferably, the ratio is within the range of 1.3 to 1.4. In other words, if the ratio of this total thickness is less than 1.2, the absolute amount of resin insulation frame member will be insufficient.
Molding defects are likely to occur due to insufficient resin filling in the details of the mold, and if the resin content exceeds 1.5 to 1.6, the amount of resin in the insulating frame becomes excessive, causing wrinkles on the electrode surface of the electrode plate 70, and causing molding defects on the effective electrode surface. There is a possibility that the electrode surface of the mold may not be completely transferred. This is because glass wool is mixed into the insulation frame as a filler, resulting in a lower apparent fluidity.
If excess resin becomes difficult to flow out of the mold as burrs, and it takes a relatively long time for the mold to completely close during compression molding, the electrode plate 70 may be stretched too much before the mold closes. This is because the liquid is compressed, leaving wrinkles on the surface. This phenomenon occurs because the mold is in uneven contact due to variations in the thickness of the electrode plate as a component, or because the mold is not completely closed.

Therefore, in this embodiment, by setting the ratio of the total thickness of the inner and outer resin insulating frame members 60a, 60b to the thickness of the electrode plate 70 within the range of 1.3 to 1.4, occurrence of these molding defects can be avoided. This is to avoid.

On the other hand, the ratio of the thickness of the outer resin insulating frame member 60b itself to the thickness of the glass wool frame member 12 is 1.0.
Preferably, the ratio is within the range of ~0.8. This is because if the outer resin insulating frame member 60b is too thin, there will be a portion where the glass wool frame material 12 is exposed on the surface of the insulating frame. On the other hand, if it is too thick, the resin covering the glass wool frame material 12 in a layered manner will shrink only on the surface after molding, resulting in molding defects such as wrinkles. The outer resin insulating frame member 60b cut out in the shape of a picture frame is sized so that the width of the short side is necessary and sufficient to cover the microchannel region, and the glass wool frame member 1
The inner resin insulating frame member 60a located between the electrode plate 70 and the electrode plate 70 is dimensioned so as not to protrude into the microchannel region.

The inner resin insulating frame member 60a may have a thickness that provides a sufficient amount of resin to bond the electrode plate 70 and the outer resin insulating frame member 60b impregnated into the glass wool frame member 12 to each other. The thickness is 0.3 relative to the thickness of the glass wool frame material 12.
It is preferable to set the ratio to about ±0.1. That is, if the thickness of the inner resin insulation frame member 60a is too thin,
Due to the presence of the glass wool frame material 12, the electrode plate 70
In some cases, the fusion bonding between the outer resin insulating frame member 60b and the outer resin insulating frame member 60b may not be completed completely, and conversely, if the resin material is too thick, excess resin material may flow out onto the effective electrode surface, causing problems such as narrowing the electrode surface. Because there is.

H. Effects of the Invention As described above, according to the present invention, by devising the overlapping of each member constituting the insulating frame, warpage of the product can be prevented, and at the same time, the insulating frame and the electrode plate can be effectively connected. By fusion bonding, it is possible to prevent the resin from seeping out onto the effective electrode surface of the molded product and to ensure the designed electrode area.

[Brief explanation of drawings]

Figure 1 is a diagram explaining the principle of electrolyte circulation type battery, Figure 2
The figure is an exploded perspective view of a conventional electrolyte circulation type stacked battery in which a large number of unit cells are stacked, and FIG. 3 is an explanatory diagram showing the constituent members of a framed electrode according to an embodiment of the present invention. 50... Framed electrode, 60... Insulating frame, 60a...
...Inner resin insulating frame member, 60b... Outer resin insulating frame member, 70... Conductive plastic electrode plate. 1
2...Glass wool frame material.

Claims (1)

[Scope of Claims] 1. An insulating frame member made of synthetic resin is provided around at least one surface of a rectangular conductive plastic electrode plate integrally with the electrode plate to constitute a framed electrode, and the framed electrode A framed electrode configured to form a battery reaction chamber surrounded by the electrode plate and the insulating frame member by overlapping the electrode plates and to allow the electrolyte to flow into and out of the battery reaction chamber via the insulating frame member. , wherein the insulating frame member has a laminated integrated structure of an inner resin insulating frame member in contact with the electrode plate, an intermediate glass wool frame member, and an outer resin insulating frame member on the outer surface. electrode. 2 Set the thickness of the glass wool frame material to the thickness of the electrode plate.
The framed electrode according to claim 1, wherein the electrode size is increased by 1.0 to 2.0 times. 3 The total thickness of the inner resin insulation frame member and the outer resin insulation frame member is 1.3 to 1.4 of the thickness of the glass wool frame material.
The framed electrode according to claim 1, which is doubled in size. 4. The framed electrode according to claim 1, wherein the thickness of the inner resin insulating frame member is 0.3±0.1 times the thickness of the glass wool frame material. 5. The framed electrode according to claim 1, wherein the thickness of the outer resin insulating frame member is 1.0 to 0.8 times the thickness of the glass wool frame material.