JPH01311574A - Electrode section for zinc-chlorine cell - Google Patents

Abstract

PURPOSE:To prevent the reduction of the current efficiency by providing a hole and/or a groove horizontally penetrating a current collecting bar on each current collecting bar and communicating adjacent partition chambers across the current collecting bar to each other. CONSTITUTION:A hole and/or a groove 14 horizontally penetrating a current collecting bar is provided on each current collecting bar 4, thus adjacent partition liquid chambers across the current collecting bar are communicated to each other. When multiple electrolyte feed ports 11 of one partition liquid chamber are almost clogged, an electrolyte flows in from the adjacent partition liquid chamber through the hole or the like provided on the current collecting bar 4, thus an extreme deficiency in chlorine does not occur, a discharge reaction proceeds between the chloride electrode of the partition liquid chamber and a mating zinc electrode across a partition cell section, the zinc electrodeposited by charging is effectively utilized. The position where the hole or the like is formed on the current collecting bar 4 is provided at the lower section of the current collecting bar, i.e., the portion near the electrolyte feed port 11 at the lower section of an electrolyte chamber 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to the electrode section of a zinc-chlorine battery, and in particular to one in which the current efficiency is improved by improving the current collecting rod.

(Prior art) A zinc-chlorine battery with a bipolar structure has a liquid-permeable chlorine electrode as a positive electrode, a liquid-impermeable zinc electrode as a negative electrode, and these are arranged oppositely through a vertical current collector rod. It constitutes a unit in which an electrolyte chamber is formed between the two electrodes.Furthermore, the electrolyte chamber is partitioned into a plurality of divided chambers by a current collecting rod, and an electrolyte supply port is provided at the bottom of each divided chamber. A battery section is formed between the units by stacking a plurality of the above units via insulating ribs, and an electrolytic solution containing zinc chloride as a main component is supplied from each electrolytic solution supply port to the divided solution chamber, and then By passing through the chlorine electrode and supplying it to the battery section, a battery reaction is caused and the battery is charged and discharged.

□To explain this with reference to FIG. 3, for example, a zinc electrode plate (2) made of liquid-impermeable dense graphite or titanium is placed as a negative electrode in a battery frame (1) made of a corrosion-resistant insulator such as polyvinyl chloride. In order to reduce polarization of the chlorine electrode as a positive electrode, a chlorine electrode plate (3) made of liquid permeable porous graphite or titanium is connected to at least one vertical current collector rod (4a) (4bH4c) made of graphite or titanium.
) (4d) to form an electrolytic solution (5), and a large number of these units are stacked in series to connect the chlorine electrode plate (3) and the zinc electrode plate (2°). They are connected via a plurality of longitudinal ribs (6) (6) to form a battery part (7).

In addition, current collector rods (4) excluding current collector rods (4a) and (4d) at both ends
b) (4c) are arranged so as to overlap vertically in relation to the ribs (6) and (6) on the front and back, so that the electrolytic solution (5) is collected by the current collector rods (4b) and (4c), respectively. The divided liquid is divided into (8a) (8b) (8c) and the battery part (7) is divided into the respective divided battery parts (7a) (7b).
It is divided into (7C).

Then, the electrolytic solution (9) containing zinc chloride as a main component, sent out from the electrolytic solution tank by the electrolytic solution pump, is divided by the supply-side manino old (10) to each divided solution (8).
a) (8b) Enter into the respective divided liquids (8a), (8b), and (8c) from the electrolyte supply ports (lla), (11b), and (11C) provided at the bottom of (8c).

Roughly, the electrolytic solution (9) passes through the chlorine electrode plates (3), respectively, to each divided battery section (7a) (7b) (7C) of the battery section (7).
) and undergo a battery reaction, then merge again at the discharge side manifold (12) and are discharged out of the system from the electrolyte discharge port (13).

The reason why a graphite rod or a titanium rod is interposed between the zinc electrode and the chlorine electrode as a current collecting rod is to make the zinc electrode and the chlorine electrode bipolar. The intervals at which these are arranged are made small in order to equalize the current density as much as possible, but for example, if the size of one battery frame (1) is i
oo.

#''X600 m'X11/+1111' In the case of stacking electrodes, current collector rods are inserted every few cm.

In addition, there are usually multiple electrolyte supply ports at the bottom of each divided solution, but in order to equalize the electrolyte flow rate for each supply port as much as possible, the area of each supply port is made small. The differential pressure is set to several tens of centimeters of water column. For this reason, usually
The supply port has a diameter of 1 to 2 mm and may become clogged if foreign matter gets mixed into the electrolyte.

[Problem to be solved by the invention]

If the electrolyte supply port is clogged in this way, if the blockage is complete, the electrolyte will not flow and normal battery reactions will hardly occur, but if the degree of clog is more than half During charging, the concentration of zinc chloride in the electrolytic straw is as high as 2 to 2.5 mol/J, so even if there is a blockage of this degree, zinc electrodeposition and chlorine generation are almost the same as when the liquid supply is normal. It happens. However, during discharge, the chlorine concentration in the electrolyte is 0.01 to 0.02 moI#! Since the chlorine electrode in the clogged divided liquid chamber has a low concentration, the chlorine concentration becomes insufficient and the rated current density cannot be maintained.

If the discharge continues in this state, the ionization of zinc in the zinc electrode that faces the chlorine electrode of the splitting solution with the electrolyte supply port clogged across the battery section will cause the ionization of zinc in the other electrodes, which are ionized at the rated current density. Because it is slower than the normal part, zinc remains on the electrode even after the zinc in the normal cell has completely dissolved. Therefore, the zinc deposited during charging is not used effectively, resulting in a decrease in so-called current efficiency.

[Means to solve the problem]

In view of this, as a result of various studies, the present invention provides an electrode section for a zinc-chlorine battery that prevents a decrease in current efficiency even if the electrolyte supply port is clogged for some reason and the electrode becomes deficient in chlorine during discharge. It is.

That is, in the present invention, a liquid-permeable graphite or titanium chlorine electrode and a liquid-impermeable graphite or titanium zinc electrode are arranged oppositely through a graphite or titanium vertical current collector rod, and a current collector rod is installed between the two electrodes. A battery section is formed between the units by stacking a plurality of units with an electrolyte chamber consisting of a plurality of divided liquid molecules separated by insulating ribs, and a battery section is provided at the bottom of each divided liquid element. In a battery with a bipolar structure, the electrolyte is supplied from the electrolyte supply port, passes through the chlorine electrode, and is supplied to the battery section to perform a battery reaction.
Each current collector rod is provided with a hole and/or groove that passes through the current collector rod in the horizontal direction, so that adjacent split liquids with the current collector rod in between are communicated with each other, and the lower part of the current collector rod is It is advantageous to provide holes and/or grooves.

(Function) By using such a current collector rod, even if the multiple electrolyte supply ports of one divided liquid droplet are almost clogged, the current can be passed through the hole provided in the current collector rod to the next one. Because the electrolyte flows in from the split liquid element, a discharge reaction proceeds between the chlorine electrode of this split liquid element and the zinc electrode that faces it across the divided battery part, without causing an extreme chlorine shortage.
The zinc deposited during charging will be effectively used.

Further, it is preferable that the hole or the like be formed in the current collector rod at the lower part of the current collector rod, that is, in the lower part of the electrolyte chamber near the electrolyte supply port. If this is attached to the upper part away from the electrolyte supply port, the electrolyte with dissolved chlorine will not be supplied to the chlorine electrode below where the holes are formed, so the split battery will be attached to the chlorine electrode. This is because the deposited zinc at the bottom of the zinc electrodes, which are opposite to each other with the electrodes in between, cannot participate in the discharge reaction.

(Example〕 Next, the present invention will be explained in detail.

As shown in Figure 2, the effective area is 2800CrIi and the thickness is 1.
A graphite fiber sheet (15) made of graphite is used as a chlorine electrode, and a graphite carbon plate (16) with a thickness of 0.8 sheets, which has the same effective area and is fired at 2000°C or more, is used as a zinc electrode, and the two electrodes are placed opposite each other. Meanwhile, the cross-sectional dimension is 10#X5
A unit is constructed with an electrolyte chamber (5) in which nine graphite collector rods of ## are arranged vertically to form eight divided liquid molecules, and this unit is connected to the electrolyte chamber (5) through ribs.
The batteries were stacked together, and a battery section (7) consisting of eight divided battery sections was provided between the units. Further, four electrolyte supply ports (11) each having a diameter of one shoe were provided at the bottom of each divided liquid droplet. Roughly speaking, as shown in Figure 1, the seven current collector rods in three of the five sets of units above, excluding the two at both ends, are placed next to each other on the side that contacts the zinc electrode at a position 10 m from the bottom end. Three sets of units using grooves (14) with a width of 2# and height of 1# are formed to communicate the matching split liquid molecules, and the other two sets of units are provided with grooves. The conventional electrode part is made up of a conventional current collector rod.

The electrolyte was circulated from the electrolyte tank to the five laminated units described above without passing through a filter normally used to remove foreign matter from the solution, and cycle operations of charging and discharging were repeated, and the electrode part of the present invention was operated every 10 cycles. Table 1 shows a comparison of the average current efficiency of the electrode section with that of the conventional electrode section.

As is clear from Table 1, the electrode section of the present invention exhibits extremely low decrease in current efficiency even when operated continuously for a long time. On the other hand, in the conventional electrode section, as the number of operating cycles increases, the amount of foreign matter in the electrolyte increases, and the electrolyte supply port gradually becomes clogged, resulting in a significant drop in current efficiency.

〔Effect of the invention〕

As described above, according to the present invention, even if a part of the electrolyte supply port becomes clogged in a zinc-chlorine battery, the current efficiency hardly decreases and stable charging/discharging operation is possible, which is an industrially remarkable feature. It is something that is effective.

[Brief explanation of the drawing]

Figure 1 is a perspective view showing an example of a current collector rod used in the electrode section of the present invention, Figure 2 is a cutaway cross-sectional view showing five stacked units of a zinc-chlorine battery, and Figure 3 is a cross-sectional view of a conventional zinc-chlorine battery. Showing the structure, (a) is a side sectional view, and (b) is the AA' of (a).
(C) is a view taken along the line BB' of (A). 1...Battery frame 2...Zinc electrode plate 3...Chlorine electrode plate 4.4a, 41), 4C, 4d .-- ---Current collector rod 5... Electrolyte solution 6... Rib 7... Battery section 7a, 7b, 7c...・Split battery part 8a
, 8b, 8c......Divided liquid to 9...
... Electrolyte 10 ... Supply side manifold 11, 11
a, 11b, l1c-: ---- Electrolyte supply port 1
2...Discharge side manifold 13...
..... Electrolyte discharge port 14 ..... Groove 15 ..... Graphite fiber sheet 1
6... Gratsy carbon plate Fig. 1 Fig. 2-, i37-

Claims (2)

[Claims] (1) A liquid-permeable graphite or titanium chlorine electrode and a liquid-impermeable graphite or titanium zinc electrode are placed opposite each other via a graphite or titanium vertical collector rod, and the two electrodes are separated by a collector rod. A plurality of units each forming an electrolyte chamber consisting of a plurality of divided liquid chambers are stacked together via insulating ribs to form a battery section between the units, and an electrolytic solution provided at the bottom of each divided liquid chamber is stacked. In a battery with a bipolar structure in which a battery reaction is performed by supplying an electrolytic solution from a supply port, passing through a chlorine electrode, and supplying it to the battery part, each current collector rod has a hole and/or An electrode part for a zinc-chlorine battery, characterized in that adjacent divided liquid chambers are communicated with each other with a current collecting rod in between by providing a groove. (2) The electrode part of a zinc-chlorine battery according to claim (1), wherein a hole and/or groove passing through in the lateral direction is provided in the lower part of the current collector rod.