JPS6247348B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a water-filled air battery, and aims to prevent deterioration of a gas diffusion electrode (hereinafter referred to as an anode). In conventional injection-type air batteries, an electrolyte with a uniform concentration is injected, so there is no particular adverse effect on the anode or the like. However, in batteries that contain a concentrated solid electrolyte such as caustic potash, water is poured into the battery to dissolve the electrolyte and make the battery operational.
In this case, water may temporarily come into contact with the anode before the electrolyte is dissolved, or a dilute electrolyte may come into contact with the anode before the electrolyte is completely dissolved. This water or dilute electrolyte has a much lower viscosity than a normal electrolyte with a uniform concentration, so it easily penetrates inside the anode, which is made of waterproof porous activated carbon, making the anode leak-proof. The problem was that the liquid properties deteriorated extremely quickly. The present invention has been made to solve the above-mentioned conventional problems, and will be described below based on drawings showing embodiments thereof. In Figure 1, 1
is an anode made of porous activated carbon treated with waterproofing.
Reference numeral 2 denotes a zinc cathode formed by adding a binder such as ethyl cellulose to zinc powder, and this zinc cathode 2 is disposed outside the anode 1. 3 is a battery case containing the anode 1 and the zinc cathode 2;
a and 4b are approximately 85% of the concentration stored inside the battery container 3.
A solid electrolyte containing caustic potash. Among these electrolytes 4a and 4b, a part 4a is disposed between the anode 1 and the zinc cathode 2, and the other part 4b is disposed between the anode 1 and the zinc cathode 2.
It is configured to cover the reaction surface 1a of. Note that one of the electrolytes 4a is obtained by heating and melting caustic potash with a concentration of 85%, pouring it into a certain mold, and taking it out after cooling, and the other electrolyte 4b is obtained by immersing the anode 1 in a molten KOH solution. Alternatively, it can be obtained by placing the anode 1 in a mold and pouring a molten KOH solution into the mold. Reference numeral 5 denotes a bag-shaped separator made of nylon cloth or the like and configured to enclose the anode 1 and the other electrolyte 4b. Although the separator 5 encloses the anode 1 in FIG. 1, it may also enclose the zinc cathode 2, and if the separator 5 is a strong perforated plate separator,
It is only necessary to insert it between the anode 1 and the zinc cathode 2. 6 is a hollow current collector embedded in the anode 1. Reference numeral 7 denotes a cushioning material made of a foam material that supports the bottom of the anode 1, and is installed at the center of the bottom of the battery case 3. 8
is a rib that protrudes upward from the bottom of the battery case 3 and holds the zinc cathode 2. Reference numeral 9 denotes a water inlet for injecting water into the battery case 3 when the battery is in use, and this water inlet 9 is formed in the battery case lid 10 that closes the upper opening of the battery case 3. Further, a thin film 11 integrated with the container lid 10 is provided inside the water inlet 9, and this thin film 11 is torn with a screwdriver or the like just before water is injected into the container 3. Note that this thin film 11 maintains complete airtightness between the water inlet 9 and the battery case 3 before being broken. 12 is a water inlet plug attached to the water inlet 9; 13 is an anode cover provided to cover the anode 1; this anode cover 13 is provided with an air hole 14 for taking in air; is sealed with vinyl tape 15 or the like until the battery is used. 16 is an anode terminal electrically connected to the anode 1, and 17 is a terminal plate taken out from the top of the zinc cathode 2. This terminal plate 17 is connected at one place and taken out as a cathode terminal (not shown). 18 is the reaction surface 1a of the anode 1
Wax, resin, etc. applied to other parts and the electrolyte surface position. Figure 2 shows a comparison of the discharge characteristics of a conventional product and a product of the present invention. C indicates a battery of the present invention in which the reaction surface 1a of the anode 1 is covered with a solid electrolyte 4b having a thickness of about 7 mm. In this case, the anode used was an anode obtained by firing and activation, which is usually called a fired carbon anode. As is clear from FIG. 2, the invention product C
It was possible to obtain discharge characteristics equivalent to those of battery A using the conventional electrolyte injection method. We also compared the leakage resistance of what is normally called an unfired carbon anode, which is obtained by adding a resin binder to waterproofed porous activated carbon, press-molding it, and then drying it. explain. That is, during continuous discharge, the electrolyte that has passed through the anode causes the anode 1 shown in FIG.
The following table shows the results of investigating the period until liquid begins to accumulate in the hollow part of the current collector 6 (period until leakage occurs) for each of the above batteries A, B, and C. Ta. In addition, as a battery
A battery with a capacity of 300Ah is used, and the thickness of the anode is 10
~13 mm, this finding is at room temperature.

[Table] As is clear from the above table, the product C of the present invention had the same characteristics as the conventional electrolyte injection type battery A. As described above, according to the present invention, since the reaction surface of the anode is covered with a solid electrolyte, by the time the anode reaction surface is exposed, the alkaline concentration in the injected water can be reduced by dissolving the electrolyte to some extent by injecting water. As a result, the problem of the anode deteriorating extremely quickly as in conventional batteries is eliminated, and since it is a water injection type battery with a built-in solid electrolyte, the electrolyte solution must be prepared separately. There is no need,
As a result, handling becomes easier and costs are lower. In addition, if both the anode and the zinc cathode are covered with a solid electrolyte, the heat-molten caustic potash will solidify on the surface of the anode and zinc cathode, increasing the cooling speed, which will speed up the manufacturing process. It has the advantage of being extremely easy to use.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal cross-sectional view of a water-injected air battery showing an embodiment of the present invention, and FIG. 2 is a graph showing a comparison of discharge characteristics between a conventional product and a product of the present invention. 1... Anode, 2... Zinc cathode, 3... Battery case, 4
a, 4b...Solid electrolyte.

Claims (1)

[Claims] 1. A porous anode subjected to waterproof treatment, a zinc cathode disposed outside the anode, a battery case containing the zinc cathode and the anode, and a combination of the anode and the zinc cathode. and a solid electrolyte disposed between the
A water-filled air cell characterized in that the reaction surface of the anode is covered with a solid electrolyte. 2. The water-filled air battery according to claim 1, wherein a fired carbon anode is used as the anode. 3. The water-filled air battery according to claim 1, wherein an unfired carbon anode is used as the anode. 4. The water-filled air cell according to claim 1, wherein the zinc cathode is a zinc cathode covered with a solid electrolyte.