JPH0348627B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrolyte circulating type stacked secondary battery using metal bromide as an electrolyte, and the flow rate and flow velocity distribution of the electrolyte flowing on the electrode plate are made uniform, and the electrolyte This prevents the occurrence of overvoltage and non-uniform electrodeposition due to non-uniformity in the flow rate, flow velocity distribution and concentration of the electrolytic solution, which occurs in the electrolytic solution, and also reduces the loss of flow pressure of the electrolytic solution.

BACKGROUND ART Conventionally, as an electrolyte circulation type laminated secondary battery such as a metal-bromine battery of this type, the one shown in FIG. 1 is known. FIG. 1 shows the main parts of this battery, in which electrodes 1 and separators 2 are alternately stacked. The electrode 1 is composed of an electrode frame 3 and an electrode plate 4, and the electrode frame 3 is provided with manifolds 5a, 5b and a large number of holes 6 for passing through bolts. Manifold 7 is also attached to the frame of separator 2.
a, 7b and a hole 8 for passing a bolt through. The thickness of the electrode frame 3 is thicker than that of the electrode plate 4, and the manifolds 5a and 5b are communicated with the space formed by the electrode plate 4 and the separator 2 through channels 9a and 9b provided in the electrode frame 3. There is. An electrolytic solution is supplied to this space from, for example, the manifold 5b, and is discharged from the manifold 5a. In the above space, the distance d between the surface of the electrode plate 4 and the separator 2, that is, the distance d from the surface of the electrode plate 4 to the surface of the electrode frame 3, is as narrow as 0.5 mm to 2.0 mm, and the vertical and horizontal distances of the electrode plate are narrow. The parts corresponding to l and w are long (w is 200 to 400 mm), so it is difficult to make the electrolyte from the manifold 5b flow uniformly through the space, that is, in parallel flow evenly in the width w direction. Have difficulty. FIG. 2 shows a case where the flow of the electrolytic solution on the electrode plate 4 is non-uniform, and FIG. 3 shows a case where it is ideally uniform.

Conventionally, as a device for rectifying the flow of the electrolysis and the like to make it uniform, a device is known in which a microchannel in which an obstacle is formed between the channels 9a, 9b and the space is provided. Although the uniformity of the flow can be improved when this obstacle is provided, it is not always satisfactory.
In other words, in order to obtain a sufficient rectification effect, (a) use in a high flow state, (b) increase the number of obstacle rows, and (c)
Narrow the spacing between obstacles near the electrolyte inlet.
For this purpose, the loss of flow pressure of the electrolyte becomes large, and therefore (a) a high-output pump for liquid circulation is required, and (b) the battery configuration increases due to the increase in internal pressure of the battery. (c) safety issues arise due to increased pressure inside the battery; and (d) gas generated inside the battery is removed by leading it out of the battery. It becomes difficult.

In order to eliminate such drawbacks, the present applicant previously proposed an electrolyte circulation type laminated secondary battery in which the length of the obstacles in the microchannel was made uneven (Japanese Patent Application No. 1974-742). The effect of reducing flow pressure loss was not necessarily sufficient.

In addition to making the lengths of the obstacles non-uniform, the present invention uses a channel between the manifold and the microchannel that is expanded toward the microchannel side, thereby reducing the flow pressure loss and the flow. The object of the present invention is to provide a metal monobromine electrolyte circulation type laminated secondary battery that can obtain a sufficient rectifying effect.

An embodiment of the present invention will be described in detail below with reference to FIGS. 4 to 7. FIG. 4 is a partially enlarged view of the electrode frame 3 of the electrode 1 of the secondary battery as described above, and shows the microchannel 10b communicating with the manifold 5b. Diagonally opposite to these manifolds 5b and microchannels 10-b are other manifolds 5b and microchannels 10 that are not shown.
A is provided. This microchannel 10
In a and 10b, three rows of divided obstacles L ₁₁ ...L _1N , L ₂₁ ...L _2N ′, L ₃₁ ...L _3N ″ are parallel to the electrolyte inflow and outflow end surfaces of the electrode plate 4. is formed.
These three rows of dividing parts w4 of obstacles are provided so that the directions of inflow and outflow of the electrolyte are shifted from each other, and the manifolds 5a, 5b and the microchannel 10a,
An enlarged channel 11 on the microchannel side is provided between the channels 10b and communicated with each other. Reference numeral 12 indicates a plurality of obstacles provided in the channel 11. The above microchannels 10a, 10b
The size of the obstacle at is the width of the electrode plate 4 w = 177
mm, the number (mm) is as shown in Fig. 5, and the electrolyte inflow/output end face of the electrode plate 4 and the obstacle L ₁₁
...L _1N and the obstacle L ₁₁ ...L _1N at a distance w ₁ = 4 mm.
L ₂₁ …L _2N ′ and the distance w ₂ = 2.5 mm, there is an obstacle L ₂₁ …
The distance w ₃ between L _2N ′ and L ₃₁ ...L _3N ″ is set to 2.5 mm, the distance between the obstacles in each row w ₄ = 2 mm, and the diameter of the obstacle 12 is set to 2φ. The dimensions of the obstacles, w ₁ to w ₄ , and the diameter of the obstacle 12 in Figure 5 are for the width w = 177 mm, and these are changed according to changes in w, and when the width w becomes w'. is γ=
It is sufficient to multiply each of the above dimensions by using w'/w as a coefficient.

Since the liquid passing through the channel 11 from the manifold 5b needs to be dispersed laterally through the interval _w1 , the dimension Lij of the obstacle becomes shorter as it moves to the right in the drawing. Further, since the intervals w ₁ , w ₄ etc. affect not only the uniformity of the flow but also the flow pressure loss, it is preferable that they are larger, but the above values were set in order to improve the area efficiency and the like.

The dimensions L _2j of the obstacles L ₂₁ ...L _2N are determined by the relationship with the obstacles L ₁₁ ...L _1N and the distance w ₄ , as shown in Figure 6.
It is determined that L _2j = 1/3 (L _1j + L _1j+1 ) + w ₄ .

However, between obstacles with dimensions L _2j and L _2j+1 , there is a distance between L 2j and L _2j +1.
An obstacle with dimension L′ _2j is installed at a distance w ₄ from L _2j+1 . Furthermore, the above relational expression does not apply to the obstacle _L11 .

The dimensions _{of the} obstacles _{L 31} . In FIG. 7, the dimensions of the obstacles L ₃₁ . . . L _3N are L ₃ j=1/2 (L _2j + L _2j+1 )−w ₄ .

Among the above obstacles L ₁₁ ...L _1N , L ₂₁ ...L _2N ′, L ₃₁ ...L _3N ″, L ₁₁ ...L _1N and N ₂₁ ...N _2N ′ prevent the flow of the electrolyte to the right in Fig. 4. It plays the role of distributing to
L ₃₁ ...L _3N '' is used to divide the flow into smaller pieces and regulate the flow.As shown in Figure 5, N ₃₁ ...N _3N has a dimension of 11 mm or less, and has many outlets that diffuse into the space. This helps to equalize the flow by maintaining the flow.

Although the above description is about the manifold 5b side, obstacles and the like are arranged in a similar manner and line-symmetrical on the manifold 5a side as well.

The arrangement of the obstacles mentioned above is also shown in Reference Photo 1. Reference photos 2 to 4 also show that these obstacles make the flow uniform. Photo 2 shows the flow rate at a low speed of 100ml/min, Photo 3 shows the medium speed of 150ml/min, and Photo 4 shows the flow rate at a low speed of 100ml/min.
The case of a high speed of 200 ml/min is shown, and it can be seen that parallel rectification occurs in almost the entire flow rate range.

If the force required and the power consumed to flow the electrolytic solution at a constant flow rate while the electrolytic solution exits the manifold 5b are expressed as pressure loss in mmHg of mercury, then
The magnitude of this loss depends on the channel shape and microchannel shape. The results of measuring the pressure loss for the distance d=1 mm are shown in FIGS. 8 to 12. As is clear from these figures,
When comparing the loss due to the channel and the sum of the loss due to the microchannel and the parallel pole part, the magnitude of the latter (value indicated by 2 to 2') is the distance d
and less dependent on the shape of the microchannel (microchannel losses are small). On the other hand, the former (indicated by 1 to 2, 2' to 1') are affected by the distance d and also change by its shape, and are more It can be seen that the loss is small in the case of the channel of the type of the present invention shown in FIG. 8, that is, the channel expanded toward the microchannel side. Additionally, a channel of the type shown in FIG. 11 has even greater losses.

As mentioned above, the present invention can uniformize the flow of electrolyte and reduce the flow pressure.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of the main parts of a conventional electrolyte circulation type stacked secondary battery, Figs. 2 and 3 are explanatory diagrams for explaining the flow of electrolyte in the electrode plate, and Fig. 4 is a front view of the main part showing one embodiment of the present invention, FIG. 5 is a front view showing the method of obstacles in the one in FIG. 4, and FIGS. 6 and 7 are the front views of the obstacles in the one in FIG. Explanatory diagram explaining the dimension calculation method, No. 8
11 are graphs showing the measurement results of the flow pressure loss of the electrolytic solution, FIG. 8 is for the present invention, and FIGS. 9 through 11 are for the conventional example. 12th
The figure is a chart showing measurement data in the case of FIG. 1... Electrode, 3... Electrode frame, 4... Electrode plate, 5
a, 5b...manifold, 10b...microchannel, 11...channel, 12...obstacle,
L ₁₁ …L _1N , L ₂₁ …L _2N ′, L ₃₁ …L _3N ″……Obstacle.

Claims (1)

[Scope of Claims] 1. An electrode plate is provided in a rectangular electrode frame, a pair of manifolds are provided in the electrode frame at diagonal positions, and channels and microchannels are provided symmetrically in communication with each manifold, An electrolyte circulation system configured to cause an electrolytic solution consisting of metal bromide to flow into the electrode frame from one manifold through one channel and a microchannel, and to flow out into the other manifold through the other microchannel and a channel. type stacked secondary battery, the channel is formed so that the channel width is wider on the microchannel side than on the manifold side, and a plurality of obstruction protrusions are provided in the channel in each of the flow direction and the flow channel width direction, A plurality of rows of obstacles are provided at intervals in a direction parallel to the flow width direction of the microchannel, and the lengths of the obstacles in the flow width direction of the microchannel are sequentially arranged from the manifold side toward the electrode plate. The microchannel is formed by dividing the obstacles into short lengths, forming a flow path between each divided obstacle, and making the flow path in each row face the obstacles in the other row. , Among the obstacles, the length of the obstacle facing the channel is set to be larger than the opening width of the channel, and the relationship between the length of each obstacle is determined in the flow path width direction of the microchannel and Also in the flow path direction, the length of the obstacle facing the channel is set to be the longest length, and each obstacle in the row facing the channel is set to have a shorter length as it moves away from the channel in the flow width direction of the microchannel. 1. A metal-bromine electrolyte circulation type laminated secondary battery comprising: