JPH0360155B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a lead-acid battery electrode plate and a method for manufacturing the same. In general, electrode plates for lead-acid batteries are made by filling a grid portion of an electrode plate base with an active material (paste). The conventionally widely used electrode plate substrate is Pb-Sb.
However, recently, in order to make batteries maintenance-free, Pb-Ca base alloys have been used.
BACKGROUND ART alloy sheets have come into use, and in order to reduce the weight of batteries, it is being considered to use a substrate with lattice parts formed by punching or expanding instead of a cast substrate. Regardless of which substrate is used, conventional electrode plates have the disadvantage that the active material is likely to fall off because both sides of a single substrate are filled with active material, shortening the life of the battery. especially
Since the Pb-Ca alloy sheet is made by rolling an ingot, the active material tends to fall off easily because the surface of the electrode plate base, which is formed by expanding or punching the sheet and forming the lattice part, is smooth. Ta. An object of the present invention is to provide an electrode plate for a lead-acid battery that can prevent the active material from falling off, and a method for manufacturing the same. In the electrode plate of the present invention, a carbon fiber cloth is polymerized on the electrode plate base, one half of the polymer is folded back with the carbon fiber cloth inside, and the other half is folded between the two halves and between each half. It has a structure in which the base lattice part is filled with an active material. To manufacture the above-mentioned electrode plate, first, a carbon fiber cloth is superimposed on the electrode plate substrate on which the lattice portion is formed, and one half of the polymer of the substrate and the carbon fiber cloth is filled with an active material. Next, the other half of the polymer is folded back to the one half side, and the active material is applied to the lattice portion of the base of the other half by pressing in a direction in which both halves of the polymer approach each other. Fill. With the above structure, the active material is sandwiched between the two substrates and is reinforced with carbon fibers, so that the active material is prevented from falling off. Furthermore, the contact area between the active material and the substrate increases, and the carbon fibers also contribute to current collection, so the utilization rate of the active material is significantly improved. Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of the shape of the electrode plate base 1 used in the present invention. This electrode plate base 1 is formed by punching a Pb-Ca alloy sheet into relatively large-diameter holes 2 and small-diameter holes 3. The holes 2 and 3 are formed regularly and the inner bone portion 4 is left between these holes.
A lattice portion 5 is constituted by the inner rib portion 4 and the inner rib portion 4 .
In the example shown in FIG. 1, in order to continuously manufacture a plurality of electrode plates, a plurality of substrates 1, 1, ... are formed in a strip-like sheet shape, and the adjacent substrates 1, 1 are mutually connected to each other. A frame portion (portion in which no hole is punched) 6 of a predetermined width is left in between. Also, each base 1
Comparatively wide frame portions 7, 7 are formed at both ends (both ends facing each other in the longitudinal direction of the frame portion 6). In the method of the present invention, first, a carbon fiber cloth 8 as partially shown in FIG. The half portion 1A is filled with an active material (paste) 10 as shown by hatching in FIG. In this case, the active material 10 is extruded through each hole of the lattice part 5 to the lower surface side of each substrate 1, and the active material 10 is sufficiently filled on both sides of the substrate of the half part 1A so that the lower surface of the substrate is covered with the active material 10. do. In this case, preferably, a paste paper 11 is placed under the substrate 1 as shown in FIG. 4a. Paste paper is 0.03~
0.04mm thick paper, usually consisting only of pulp fibers,
When this is assembled into a battery together with the electrode plates, after being charged and discharged for a short period of time after formation, it disintegrates into pieces and falls to the bottom of the battery case. After filling the active material into the half part 1A of the substrate 1 as described above, as shown in FIG. It is folded back toward the half part 1A side, and both halves 1A and 1B are overlapped with the active material 10 interposed therebetween. Next, the half part 1B is pressed in the direction of approaching the half part 1A to polymerize the frame parts 6 and 7, respectively, and the active material 10 is made to protrude above the half part 1B, and the protruding active material is uniformly spread out. The active material 10 is evenly filled on the upper surface of the half part 1B. Now, as shown in FIG. 4d, paste paper 11' is superimposed on the active material 10 on the upper surface of half part 1B.
It is preferable to prevent the active material 10 from being damaged in subsequent steps. After folding the substrate in half as described above and filling the active material between them, the substrate 1 shown in FIG.
1. Cut the frame ribs 6 between them at the center to separate them into a plurality of electrode plates, and punch out the wide frame ribs 7 to form ears in this part, as shown in FIG. 5. As shown in FIG.
3 and an electrode plate 15 having ears 14 are obtained. When cutting the electrode plate in this way, each cut is deformed and joined together, closing the opening of the bag, so the active material is placed between the halves 1A and 1B of the electrode plate base 1. It becomes trapped and becomes difficult to fall out. In the example, the thickness was made for the anode so that the weight was equal to that of the base of currently commercially available storage batteries.
A 0.4 mm Pb-Ca alloy sheet was used, and the width of the sheet was adjusted so that the width of the electrode plate was the same as that of the commercially available product.
It was set to 278mm. And virtual 10 on this sheet
A hole 2 with a diameter of 8 mm was drilled in the center of each square of a grid consisting of a collection of squares of mm squares, and a hole 3 with a diameter of 3 mm was bored at each intersection of the grid to form a grid portion 5. The carbon fiber cloth used in this example was used to absorb hydrocarbons such as benzene using _H2 gas as a carrier gas.
Approximately 15μ in diameter made by pyrolysis at 1100℃
The long fibers were further heat-treated at about 300°C, and then woven into a plain weave to form a cloth with a width of 238 mm having a grain size sufficiently smaller than the holes in the lattice portion of the base. In this example, in order to improve the adhesion between the carbon fiber cloth and the active material, the cloth obtained as described above was subjected to surface treatment with 60% _HNO3 at a temperature of 120°C for 72 hours. Then, after degreasing and cleaning, electrolytic plating was performed in a lead fluoride bath to leave lead attached to the surface. The carbon fiber cloth thus produced was placed on the grid portion of the base. The height of the electrode plate obtained in this example was 122 mm.
The width was 142 mm, the width of the left and right frame ribs 12, 12' shown in FIG. 5 was 1 mm, and the width of the upper rail 13 was 2 mm. Further, the length l of the ear portion 14 was 18 mm, the width d was 15 mm, and the thickness of the electrode plate was 1.6 mm.
The weight of the base of the electrode plate thus produced, including the weight of the carbon fiber cloth, was approximately the same as that of currently commercially available cast bases, and was about 60 g per plate. Also, using a 0.3 mm thick sheet for the cathode, a 1.2 mm thick electrode plate was made in the same manner as above. The weight of the substrate per cathode plate was approximately the same as that of a commercially available product, and was about 45 g per cathode plate. Initial performance tests and life tests were conducted on a lead-acid battery using the cathode and anode plates produced as described above and a conventional equivalent commercially available product (using a cast base). The battery used in the experiment was an N50 _Z type, and one cell consisted of five anode plates and six cathode plates, and the amount of anode active material per cell was 420g and the amount of cathode active material was 410g.
g. In conducting the initial performance test, chemical formation was carried out by applying a constant current of 15.5 A for 18 hours in a constant temperature water bath at 40°C. After formation, discharge at a rate of 5 hours (25℃, 9.6A discharge, final voltage 10.5V)
Then, a discharge of 2 hours and 11 minutes at 9.6A (21AH discharge) was performed, and after cooling this to -30℃, a 300A discharge (final voltage of 6.0V) was performed to compare the Yin and Yang of the conventional commercial product and the above example. Initial performance comparisons were made with those using electrode plates. The results were as shown in the table below.

[Table] Next, in the life test, after discharging at 200A x 1sec and pausing for 1sec three times, 25A limited 15V constant voltage charging was performed for 11 minutes, and 10A constant current discharge was performed for 16.5 minutes.
The test consisted of 48 cycles per day of 30 minutes per cycle with 2.4 minutes of rest, and 45°C and -15°C every 24 hours.
The test was conducted in combination with repeated thermal cycles at ℃. The degree of deterioration between the two was then compared every 240 cycles. The results of this cycle life test are shown in FIG. 6, in which curve a is the case when the electrode plate of the present invention is used, and curve b is the case when the conventional electrode plate is used. Further, the straight line c is a life judgment line. From FIG. 6, it can be seen that when the electrode plate of the present invention is used, the life is significantly extended. In the above description, a base body having a grid portion formed by punching is used, but it goes without saying that a base body having a grid portion formed by expanding processing or a base body formed by casting may also be used. As described above, according to the electrode plate of the present invention, the active material is held between the folded halves of the base, and the active material is reinforced with the carbon fiber cloth.
It is possible to prevent the active material from falling off the base, and the life of the battery can be extended. In particular, since the active material is filled between the two halves of the polymer and the lattice part of each half, the contact area between the active material and the substrate is approximately twice that of the conventional one, and carbon fibers are used to collect current. Since the active material also contributes, it is possible to increase the utilization rate of the active material and suppress a decrease in battery capacity. Further, according to the production method of the present invention, one half of the polymer is filled with an active material, and the other half of the polymer is folded back and pressed in a direction to bring the two halves closer together. Since the lattice portion of the other half is filled with the active material, both halves are reliably filled with the active material, and the electrode plate is able to approximately double the contact area between the active material and the substrate compared to the conventional one. Can be easily manufactured.

[Brief explanation of drawings]

Fig. 1 is a plan view showing a part of the substrate used in the present invention, Fig. 2 is a plan view showing a part of the carbon fiber cloth used in the invention, and Fig. 3 is a step in manufacturing the electrode plate of the present invention. A plan view showing a state in which half of the polymer of the base and carbon fiber cloth is filled with an active material,
Figures 4 a to d are cross-sectional views showing the steps of manufacturing the electrode plate of the present invention, Figure 5 is a front view of the electrode plate of the present invention, and Figure 6 is a line showing the results of the life test. It is a diagram. DESCRIPTION OF SYMBOLS 1... Electrode plate base, 5... Grid part, 8... Carbon fiber cloth, 10... Active material.

Claims (1)

[Claims] 1. A carbon fiber cloth is polymerized on an electrode plate substrate having a lattice portion, and one half of the polymer of the substrate and the carbon fiber cloth is placed on the inside with the carbon fiber cloth inside. An electrode plate for a lead-acid battery, characterized in that the other half is folded back, and an active material is filled between both halves of the polymer and in the lattice portion of the base of each half. 2. A step of overlaying a carbon fiber cloth on an electrode plate substrate having a lattice portion, a step of filling one half of the polymer of the substrate and the carbon fiber cloth with an active material, and a step of filling the other half of the polymer. a step of folding the part toward the one half side, and a step of filling the lattice part of the base of the other half with the active material by pressing the two halves of the polymer in a direction in which they approach each other. 1. A method of manufacturing an electrode plate for a lead-acid battery, the method comprising: