JPH0131667B2 - - 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 secondary battery.

B. Summary of the Invention The present invention aims to obtain an electrode for a circulating electrolyte battery that can supply a uniform flow to the electrode surface of a battery reaction chamber without increasing the pressure loss of the electrolyte.
A wide curved path is formed in the vicinity of the outlet of the electrolyte flow path to the rectifying mechanism, and guide vanes are provided to divide the electrolyte along approximately the center of the wide curved path, and the opening width of the outlet is The present invention relates to an electrode for an electrolyte circulation type battery, in which a wide protrusion is provided facing the outlet part, and the end part of the guide vane is smoothly and integrally connected to the protrusion at the outlet part.

C. Prior Art FIG. 1 is a basic configuration diagram of a metal-halogen battery, which is one of the batteries in which the electrode according to the present invention is used. In this battery, a single cell 1 is partitioned by a diaphragm (separator) 2, and a positive electrode chamber 3 and a negative electrode chamber 4 are formed on both sides of the cell. It is configured by arranging a negative electrode 6. In the positive electrode chamber 3, positive electrode liquid is circulated from a positive electrode liquid storage tank 7 by a pump 9, and in the negative electrode chamber 4,
The negative electrode liquid is circulated from the negative electrode liquid storage tank 8 by a pump 10 . Note that 11 and 12 are valves that are opened during charging and discharging.

FIG. 2 is an exploded perspective view showing an example of such a battery having a bipolar laminated structure. Each of the electrodes 5 and 6 is configured such that, for example, the right side is the positive electrode 5 and the back side, that is, the left side, is the negative electrode 6. Although the positive electrode 5 and the negative electrode 6 have the same shape individually, they are used as a pair. When combined, the electrolyte passages are arranged to be offset (for example, in symmetrical positions rotated 180° relative to each other). Each of the electrodes 5, 6 and the separator 2 is held by frames 31, 21, sandwiched and stacked from both sides by end plates 13a, 13b, and bolts 14 are inserted into bolt holes 39 provided in each frame. By penetrating and tightening, the whole is constructed as one piece.

One end plate 13a is provided with a positive electrode liquid inlet 15a and a negative electrode liquid inlet 15b, and the other end plate 1
3b has a positive electrode liquid outlet 16a and a negative electrode liquid outlet 16.
b is provided. Now, showing the path for only the positive electrode liquid, the positive electrode electrolyte that enters from the positive electrode liquid inlet 15a passes through the lower manifolds 22 and 32 provided in each frame 21 and 31, and then flows through the electrolyte liquid inflow path. The flow is divided into a certain channel 35, further rectified through a microchannel 36 that rectifies the electrolytic solution below, and is supplied from there to the surface of the electrode section 30 as a parallel flow. The positive electrode electrolyte then passes through the upper microchannel 36 and collects in the channel 34, which is an electrolyte outflow path, and flows into the upper manifold 32.
The liquid flows out through the upper manifolds 22 and 32 and reaches the positive electrode liquid outlet 16a.

D Problems to be Solved by the Invention By the way, in the conventional electrode configured such that the electrolyte flows diagonally, it is good if the area of the electrode part 30 is small, but it is not good if the area of the electrode part 30 is large. However, it is difficult to uniformly distribute the electrolytic solution on the surface of the electrode portion, resulting in high pressure loss in the microchannel 36.

In the case of metal (e.g. zinc)-halogen (e.g. bromine) batteries, if the electrolyte flows unevenly within a single cell, concentration non-uniformity will occur, leading to non-uniform electrodeposition.
As a result, current density becomes non-uniform and battery efficiency decreases. Furthermore, when the pressure loss increases, it is necessary to increase the pump power to flow the same amount of electrolyte, which reduces battery efficiency.

Here, the present invention has been made for the purpose of solving such problems.

E Means for Solving the Problems The electrode for an electrolyte circulation type battery according to the present invention includes: a rectangular electrode plate; a synthetic resin insulating frame provided around at least one surface of the electrode plate; an electrolytic solution flow port bored approximately diagonally in the frame; a pair of electrolyte flow paths that are provided in communication with the electrolyte flow port and each open at the center of one opposite side of the insulating frame; A framed electrode comprising a pair of rectifying mechanisms provided along both sides and adjacent to the outlet of each electrolyte flow path, wherein the framed electrode is surrounded by the insulating frame on the electrode plate of the framed electrode. forming a battery reaction chamber; causing an electrolytic solution to flow into the battery reaction chamber from the one flow path through one of the rectifying mechanisms; and causing the electrolyte to flow out from the other flow path via the other rectifying mechanism. In the electrolyte circulating battery electrode configured as above, a wide curved path is formed in the vicinity of the outlet of the electrolyte flow path to the rectifying mechanism, and electrolysis is carried out within the wide curved path along the center of the curved path. A guide vane for separating the liquid is provided, a protrusion wider than the opening width of the outlet is provided in a portion of the straightening mechanism adjacent to the outlet of the flow passage facing the outlet, and an end of the guide vane is further provided. The above-mentioned object is achieved by having the part smoothly and integrally connected to the projection at the exit part.

F Function The present invention provides a framed electrode in which the outlet of the electrolyte flow path to the electrolyte rectifying mechanism for distributing the electrolyte to the surface of the electrode plate is provided at the center of the top and bottom parts. A wide curved path is formed near the outlet of the electrolyte flow path to the rectifying mechanism, guide vanes are provided in the wide curved path to divert the electrolyte, and a protrusion wider than the opening width of the outlet is provided. The guide vanes are provided facing the exit portion, and the guide vanes are provided along the approximate center of the vicinity of the wide curved path, and are smoothly connected to the protrusion at the exit portion. The feature is that the electrolyte flowing out is divided into two streams.

Furthermore, the present invention does not simply provide a rectifying mechanism (microchannel) between the electrolyte flow path outlet and the reaction chamber, but rather a flow path that separates the electrolyte from within the electrolyte flow path. In other words, it is characterized in that guide vanes are arranged between the inside of the electrolyte flow path and the rectifying mechanism.

In other words, conventionally, when guiding the electrolyte flow path of the insulating frame from the electrolyte flow port (manifold) in the corner partition to the center of the upper and lower sides of the insulating frame, the opening of the battery reaction chamber of the electrolyte flow path The vicinity was curved, and the flow rate and flow velocity were to change between the left and right sides of the outlet. As a result, the non-uniformity of the flow distribution of the electrolytic solution can no longer be resolved even if the rectifying mechanism after the outlet section performs rectification and dispersion.

However, if the electrolyte flow is divided from the point where the electrolyte flow path is curved as in the present invention, the above-mentioned problem can be solved. When the guide vanes for dividing the electrolyte and the protrusions facing each other at the outlet of the electrolyte flow path (which may form part of the rectifying mechanism) are formed integrally, the protrusions may be separated on the left and right sides. The respective flow rates of the electrolyte flowing through the electrolyte can be made significantly more uniform than in the case where this does not exist.

Furthermore, if the electrolyte is divided into multiple parts directly from the manifold in different directions, differences will likely occur in the divided flow rates, but in the present invention, the electrolyte is taken out from the manifold through one flow path, and a rectification mechanism (microchannel) is used. The flow is initially divided in the same direction and then gradually in opposite directions near the curved wall, and the flow is divided smoothly along the curved wall.

G. Embodiment FIG. 3 is a structural plan view showing an embodiment of the electrode according to the present invention, and the back side also has the same structure (rotated by 180 degrees with respect to each other). FIG. 4 is a - sectional view in FIG. 3. In these figures, an introduction channel 35 for introducing the electrolytic solution from the manifold 32 onto the electrode part 30 is provided in the frame part 31 so that one end communicates with the manifold 32 and the outlet opens at the center of the bottom part. Further, in the introduction channel 35, a guide vane 37 having an L-shaped local portion is provided near the exit.

The electrolytic solution led from the manifold 32 through the introduction channel 35 is divided into two parts by the guide vanes 37 as shown by the arrows in the figure, and from near the center of the bottom, the electrolytic solution is introduced into the microchannels 36a and 36b.
It flows into the surface of the electrode section 30 through the. Further, the electrolytic solution passing through the surface of the electrode section 30 is transferred to the upper microchannels 36a, 36b leading-out channels 34.
It is derived from near the center of the upper side.

Both microchannels 36a and 36b have a symmetrical shape, with 36a having at least two rows of protrusions, and 36b having at least two rows of protrusions.
It consists of a plurality of rows, preferably three rows of protrusions. These microchannels are connected to the electrode section 30
Its role is to flow a parallel flow with a uniform flow rate and flow velocity distribution on the surface.

According to the electrode configured in this way, the electrolytic solution is distributed onto the electrode plate into two parts, such as the bottom middle part, and is supplied through the microchannel, so that the electrolytic solution can be evenly distributed. Therefore, compared to conventional electrodes, a uniform parallel flow of electrolyte can be supplied to the electrode portion with a relatively sparse microchannel configuration. Although this embodiment shows the case where the manifolds 32 through which the electrolytic solution passes are provided on both sides, they may be provided on the upper and lower sides.

As explained above, according to the present invention, an electrode having the following effects can be realized.

(1) Pressure loss of the electrode liquid is reduced, improving battery efficiency. This is due to the sparse structure of the microchannel and the guide vanes within the channel.
According to actual measurements, the electrode area is 800 cm ² and the flow rate is 240 cm.
When flowing electrolyte (kinematic viscosity 6cp) at ml/min,
A pressure drop of 0.57 m in the water column was observed compared to the conventional model.

(2) The microchannel configuration can be made sparse, making the overall configuration simple.

(3) The electrolyte on the electrode plate is uniformly supplied from the bottom to the top, resulting in uniform electrodeposition, preventing dendrite formation, and improving battery performance. There is an effect.

H Effects of the Invention As described above, the present invention does not increase the pressure loss of the electrolytic solution and improves battery efficiency. Furthermore, the microchannel structure can be made sparse, and the overall structure can be simplified. Furthermore, the electrolytic solution on the electrode plate is uniformly supplied from the bottom to the top, resulting in uniform electrodeposition, preventing the formation of dendrites, and improving battery performance.

[Brief explanation of drawings]

Figure 1 shows the metals for which the electrode according to the present invention is used.
A basic configuration diagram of a halogen battery, FIG. 2 is an exploded perspective view showing an example of a bipolar laminated structure of such a battery, and FIG. 3 is a configuration plan view showing an embodiment of an electrode according to the present invention. FIG. 4 is a - sectional view in FIG. 3. 30... Electrode part, 31... Frame part, 32... Manifold, 34... Derivation channel, 35... Introducing channel, 36a, 36b... Microchannel, 37... Guide vane.

Claims (1)

[Claims] 1. A rectangular electrode plate; A synthetic resin insulating frame provided around at least one surface of the electrode plate; and an electrolyte flow port bored approximately diagonally through the insulating frame. a pair of electrolyte flow passages that are provided in communication with the electrolyte flow port and each open at the center of one of the opposing sides of the insulating frame; and an outlet portion of each electrolyte flow passage along the both sides. a pair of rectifying mechanisms provided adjacent to the framed electrode; a battery reaction chamber surrounded by the insulating frame is formed on the electrode plate of the framed electrode; An electrode for an electrolyte circulation type battery configured to allow the electrolyte to flow in from one of the flow paths through one of the rectifying mechanisms; and to cause the electrolyte to flow out from the other flow path through the other flow path, A wide curved path is formed near the outlet of the electrolyte flow path to the rectifying mechanism, and a guide vane is provided in the wide curved path to divert the electrolyte along a central portion of the curved path, and the rectifying mechanism includes: A protrusion wider than the opening width of the outlet is provided in a portion adjacent to the flow passage outlet, facing the outlet, and an end of the guide vane is smoothly and integrally connected to the protrusion at the outlet. An electrode for an electrolyte circulation type battery, which is characterized by a smooth structure.