JPH0370349B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a liquid circulation type stacked battery in which the flow rate, flow velocity distribution, etc. of the electrolytic solution flowing on the electrodes are made uniform.
The present invention provides a liquid circulation type stacked battery that solves various problems such as overvoltage and non-uniform electrodeposition caused by non-uniform concentration.

FIG. 1 is an exploded perspective view of a conventional liquid circulation type stacked battery. In the figure, reference numeral 1 denotes an electrode having an electrode frame 11, and manifolds 13, 15 and channels 14, 16 leading from the manifolds 13, 15 to the electrode plate 1a are provided above and below the electrode frame 11. 2 is a separator equipped with a frame 21;
Manifolds 23 and 25 are provided, respectively. Reference numerals 3 and 3a are current collector electrodes provided with frames 31 and 31a. Electrodes 1 and separators 2 are stacked alternately and interposed between current collector electrodes 3 and 3a. Note that the current collecting electrode 3a is also provided with a manifold, a channel, and a terminal 37a, respectively. 4,
4a is an end plate arranged on the outside of the current collecting electrodes 3, 3a. 6 is a catholyte inlet provided on the end plate 4a, 7 is an anolyte inlet, 8 is an anolyte outlet provided on the end plate 4, 9
is the catholyte outlet, and these are the through holes 1 provided in each frame.
2 and 22 are integrally connected by a tightening bolt 5 inserted therein.

In the battery configured as described above, the distance between the electrode plate 1 and current collecting electrodes 3, 3a and the separator 2 is extremely narrow, approximately 0.6 to 3 mm, so the electrolyte flowing between the electrodes and the separator is as shown in Figure 2a. ,b,c
The distribution is as shown in , and the flow velocity tends to be faster only at the center or edge of the electrode plate. Such non-uniformity in flow rate and flow velocity distribution is caused by the head difference (△h) from the electrolyte outlet to the inlet of the liquid storage tank (not shown);
Experiments have shown that this is influenced by the diameter, length, etc. of the liquid delivery pipe. Therefore, in order to solve these various factors, various improvements have been made to the head (△h), pipe diameter, pipe length, etc. However, there are limits to these improvements, and satisfactory results have not always been obtained. . Therefore, the flow turbulence caused by the above factors is directly applied to the electrode surface from the manifold through the channel, resulting in non-uniform distribution of flow rate and flow velocity as shown in Figure 2. Undesirable problems such as overvoltage and non-uniform electrodeposition occurred.

The present invention was made in order to solve the above-mentioned conventional problems, and it is possible to provide an obstacle between the channel of the electrode frame and the electrode plate, thereby rectifying the electrode liquid flowing into the electrode plate. In this way, the distribution of flow rate and flow velocity is made uniform. The present invention will be explained below with reference to the drawings.

FIG. 3 is a front view showing essential parts of an embodiment of the present invention, and FIG. 4 is an enlarged sectional view taken along line A-A. In both figures, 1 is an electrode plate, 11 is an electrode frame, and 13 is a manifold, which are provided on the diagonal of the electrode frame 11. 14 is a channel that communicates with the manifold 13. Reference numeral 17 denotes a microchannel provided on the electrode plate 1a side of the electrode frame 11, and a large number of obstacles (hereinafter referred to as obstacles) 18 protrude parallel to the channel 14 and to the same height as the surface of the electrode frame 11.
a, 18b, 18c (hereinafter the obstacles may be collectively referred to as 18), and each obstacle 1
Grooves 19 provided on both sides of 8a, 18b, 18c
a, 19b, and 19c, and the groove 19a
is in communication with channel 14. The electrolytic solution sent by a pump (not shown) is sent to the microchannel 17 via the manifold 13 and the channel 14, and the flow rate is evenly distributed by the obstacle 18, so that when it reaches the electrode plate 1a, it is evenly distributed on the left and right sides. The flow velocity is , and the direction of velocity is vertical. Although not shown, the microchannel 17 is also provided symmetrically below the electrode 1 (in this case, on the electrolyte outlet side).

An example of the arrangement of the obstacles 18 in the microchannel 17 is shown in FIG. Note that FIG. 5 shows a microchannel 17 provided under the electrode 1 (see 16 in FIG. 1). In this embodiment, the obstacles 18 are provided in three stages, and the interval between each stage is 1 mm. The flow length l ₁ of the first stage obstacle 18a is long on the inlet side of the channel 16 and becomes shorter toward the downstream side (the flow direction of the electrolyte is indicated by an arrow). Further, since a small gap g ₁ is provided between each obstacle 18a, the electrolyte flows in the direction of the arrow through the groove 19a, and flows into the upper groove 19b through each gap g ₁ .

The second-stage obstacle 18b is slightly shorter on the left side of the figure, then becomes longer and becomes shorter toward the right, and is slightly longer at the right end. The electrolytic solution sent from the gap _g1 of the first stage obstacle 18a passes through the groove 19b to the second obstacle 1.
It is sent further upward through the gap _g2 of 8b. The third stage obstacles 18c are long and short ones arranged based on calculation and experimental results, and end at a position approximately two-thirds of the width L of the electrode plate 1a, and then on the right side. An open portion 20 is formed. Gap g ₂ of second stage obstacle 18b
The electrolytic solution that has passed through the groove 19c passes through the gap _g3 of the third stage obstacle 18c and the opening 20, and is sent into the electrode plate 1a. Note that the obstacles 18a, 18b, and 18c at each stage have a gap g ₁ ,
g ₂ and g ₃ are provided offset from each other so that they do not overlap on the same line.

Next, examples of the present invention are as follows.

(1) Electrode plate Width L 190 mm, Height width 220 mm (2) Microchannel Width 190 mm, Height total width 7 to 13 mm (3) Length l of first stage obstacle 18a ₁ From left: 22.5 mm, 24 mm, 28 mm, 18 mm , 12mm, 8mm…
...2mm (4) Length l of second stage obstacle 18b ₂ From left: 9mm, 22mm, 27mm, 23mm, 15.5mm...3
mm, 5.5mm (5) Length l of the third stage obstacle 18c ₃ From left: 1.5mm, 2mm, 5.5mm, 6mm, 6mm, 6mm,
3.5mm, 3mm...2.5mm, 6mm left and right open length
52mm (6) Width of the obstacle 18 W ₁ , W ₂ , W ₃ 2 mm each (7) Gap g ₁ , g ₂ , g ₃ of each obstacle 18a, 18b, 18c 1 mm each (8) Obstacle 18a, 18b, 18c Top and bottom spacing 1mm each (9) Electrolyte flow rate 40ml/min ~ 200ml/min (10) Head (△h) -50cm ~ 50cm (If the storage tank inlet is higher than the electrolyte outlet, it is considered a negative value) ( 11) Distance between electrode plate 1a and separator 2: 0.6mm~
2 mm As a result of the above implementation, a substantially uniform flow rate and flow rate were obtained over the entire surface of the electrode plate. Note that △h>
At 50 cm, the flow direction is vertical, but the flow velocity at the center of the electrode is slower than at the edges. Furthermore, when Δh<-50cm, the flow velocity becomes faster in the center. In addition, the flow rate is 40
Below ml/min, the direction of the flow velocity deviates slightly from the vertical direction, and the flow velocity increases closer to the channel entrance. When the flow rate was 200 ml/min or more, the flow was almost uniform, but the flow rate was slightly faster in the center.

From the above, the following became clear when the present invention was implemented.

(1) If the distance between the electrode plate and the separator and the head △h are constant, a wide range of flow rate (40ml/min ~
200ml/min), uniform flow rate distribution and uniform flow rate distribution can be obtained.

(2) The head difference △h between the electrolyte outlet and the liquid storage tank is ±50cm.
It can be expanded to.

(3) By providing a uniform flow into the cell chamber, it is possible in particular to uniformly electrodeposit cathodically deposited metals, such as zinc, onto the electrode plates.

(4) It is possible to prevent overvoltage due to non-uniform electrolyte concentration and localization of battery reactions due to non-uniform flow.

A representative example of the above embodiment is shown in the reference photograph. In each of the reference photos a, b, c, and d, the liquid reaches the microchannel from below through the manifold and channel, and after being rectified, flows upward on the electrode plate.
It goes through the upper microchannel and channel to the manifold.

In the above explanation, numerical values were shown for the obstacle flow, width, gap, interval between each stage, etc., but the present invention is not limited to these, and the size of the electrode, the head (△h), the pipe size, etc. It can be changed as appropriate depending on the diameter, length of the pipe, etc.

As described in detail above, according to the present invention, the flow rate and flow velocity distribution of the electrolytic solution flowing on the electrode plate can be made uniform, so that generation of overvoltage, non-uniform electrodeposition, etc. can be prevented. Therefore, a battery with high accuracy and long life can be realized.

[Brief explanation of drawings]

Figure 1 is an exploded perspective view of a conventional liquid circulation type battery, Figures 2 a, b, and c are flow distribution diagrams of the electrolyte, and Figure 3 is an exploded perspective view of a conventional liquid circulation type battery.
The figure is a front view of the main part of the embodiment of the present invention, FIG. 4 is an enlarged sectional view taken along line AA, and FIG. 5 is an explanatory diagram of the microchannel embodiment. 1: Electrode, 1a: Electrode plate, 11: Electrode frame, 1
3, 15: Manifold, 14, 16: Channel, 17: Microchannel, 18, 18a,
18b, 18c: Obstacle, 2: Separator.

Claims (1)

[Claims] 1. A plurality of electrodes and separators are alternately laminated, and the electrode is composed of an electrode frame and an electrode plate fitted in the electrode frame, and the electrode frame has a manifold. In a liquid circulation type stacked battery in which microchannels are formed approximately diagonally and further connected to the manifold via channels on the surface of the electrode frame, the microchannels are connected to a plurality of obstacles and the obstacles. a groove formed around an object, and the plurality of obstacles are formed by dividing a plurality of rows formed parallel to the electrolyte inflow and outflow end surfaces of the electrode plate into a plurality of parts by a dividing groove, The dividing portions of the plurality of rows of obstacles are provided so that the directions of inflow and outflow of the electrolyte are shifted from each other, and the length of the obstacles in the plurality of rows in the longitudinal direction is longest at a position between the center of the electrode plate and the channel. A liquid circulation type stacked battery characterized in that the obstacle is not formed in a farthest position of the row farthest from the channel.