KR19980026227A - Grid with new punching arrangement - Google Patents

Abstract

Batteries using a negative electrode grid having elliptical longitudinal and transverse punching arrangements can prevent short circuits and cracks, resulting in improved battery capacity, lifetime and yield.

Description

Grid with new punching arrangement

[Industrial use]

The present invention relates to a grid having a novel punching arrangement, and more particularly, by arranging the punching arrangement of an elliptic cathode grid in a vertical and horizontal direction to prevent separation of the active material in the process of winding the electrode plate, A grid with a novel punching arrangement that can prevent shorts and deterioration of capacity.

[Prior art]

As portable electronic devices such as cameras, camcorders, portable CD players, portable radio / recorders, notebook computers, computers, pagers, or mobile phones become more popular, the batteries required for their operation require higher capacity and longer life. It is becoming.

As described above, a battery having a wide range of uses and a high demand is used to convert chemical energy into electrical energy by using a difference in contact potential between suitable materials. The technical classification of the battery is that the primary battery is discharged only to convert chemical energy into electrical energy, the secondary battery can be repeatedly discharged and charged, and the fuel that converts combustion heat of hydrocarbons into electrical energy as it is. It can be classified into a battery and a solar cell that converts light energy into electrical energy. Moreover, according to the structure of electrolyte solution, it can classify into an alkaline battery, a solid electrolyte battery, a non-aqueous solution battery, etc. According to the appearance of a battery, it can be classified into a cylindrical battery, a button type battery, and a coin type battery.

The winding plate group refers to a product manufactured by winding a plate and a separator in a spiral manner. A battery, an electrolytic capacitor, and the like are representative examples thereof. An example is demonstrated.

A battery having a double-cylinder (Jelly-Roll type) structure is a group of winding electrode plates that discharges a current consisting of a positive electrode, a negative electrode, and a separator to prevent short circuits thereof, an electrolyte, and a positive terminal and a negative terminal. . The more detailed structure thereof will be described with reference to the nickel-hydrogen battery shown in FIG. 3 as an example. Cylindrical nickel-metal hydride battery is a positive electrode plate 15 coated with Ni (OH) ₂ positive electrode active material and a negative electrode plate which is a hydrogen storage alloy coated with a negative electrode active material mainly composed of LaNi ₄ , MmNi ₅ , Ti-Fe or Ti-Ni alloy A separator 41 made of a nonwoven fabric, a cellophane tape, or the like, and a terminal cap 56 of the positive terminal and the negative terminal, and the storage device, to prevent the short circuit between the 43 and the positive electrode plate 15 and the negative electrode plate 43. It includes a case 58 to play a role, and has a safety valve 55, a sealing plate 53, an insulating ring 51, an insulating plate 59.

When the negative electrode active material is a hydrogen storage alloy, the positive electrode active material is a nickel hydroxide, and the electrolyte solution is an aqueous potassium hydroxide (KOH) solution, the hydrogen storage alloy formed by decomposition of water in the electrolyte solution is stored and discharged. Is discharged by discharging necessary hydrogen into electrolyte solution, and the charging and discharging reaction formula is as follows.

Discharge

Anode: Ni (OH) ₂ + OH ^- ↔ NiOOH + H ₂ O

charge

Discharge

Negative _{electrode: M + H 2 O ↔ MH} + OH -

charge

Discharge

M + 2NiOOH ↔ MH + 2Ni (OH) ₂

charge

In the above reaction formula, M represents a hydrogen storage alloy capable of absorbing and releasing hydrogen ions, and there are AB ₅ system using rare earth elements and AB ₂ system using Ti, Zr, V and the like. In the above formula, the positive electrode and the negative electrode of the nickel-metal hydride battery can be charged and discharged hundreds of times or more according to the above reaction formula.

A wound electrode plate group including a cylindrical nickel-metal hydride battery having such a function and structure inserts an electrode part wound through a separator between positive and negative plates inside a can of a predetermined size, injects an electrolyte therein, and then inserts an electrolyte into the upper part of the can. Manufactured by mounting the cap assembly.

The negative electrode active material support, that is, the grid, which is used for the negative electrode of the nickel-metal hydride battery, is generally manufactured by forming a hole in steel and then plating nickel, as shown in FIG. 1A. The pattern has only an elliptical transverse punching arrangement or only a round punching arrangement as shown in FIG. 2B. However, such a conventional grid maintains the binding force with the active material only by a binder injected into the negative electrode paste, so that the charging and discharging cycle of the battery proceeds and the force on the electrode surface due to mechanical force or carelessness during the process. When this is applied, the active material may be dropped from the grid or crack may occur, causing contact failure or short circuit with the inner wall of the can, which in turn increases the internal pressure of the battery and decreases the capacity, thereby shortening the battery life. have.

The present invention has been made to solve the problems of the prior art as described above, the object of the present invention is to prevent the short circuit of the pole plate and to reduce the contact failure as a result of the pole plate which can improve the capacity, life and yield of the battery To provide a grid that is useful for.

1A is a plan view of a cathode grid having a conventional elliptical transverse punching arrangement,

1B is a plan view of a cathode grid having a round punching arrangement.

Figure 2 is a plan view of the cathode grid having an elliptical longitudinal and elliptical transverse punching arrangement according to an embodiment of the present invention.

3 is a schematic exploded view showing the structure of a nickel-metal hydride battery which is a type of conventional wound electrode group.

* Description of the symbols for the main parts of the drawings *

15. Positive plate

41. Separator

43. Negative plate

In order to achieve the object of the present invention as described above, the present invention provides a grid for an anode plate in which the elliptical longitudinal and elliptical transverse punching arrangements are alternately arranged one by one. Here, the above-mentioned elliptical punching preferably has a long diameter of 2.0 to 2.2 mm and a short diameter of 1.7 to 1.9 mm, and is preferably used for a wound electrode group battery.

EXAMPLE

Representative Example

Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

In order to produce the grid used for the negative plate of the wound electrode group, one row of the negative plate grid punching arrangement is alternately arranged in the transverse direction of the elliptical, and the next row is the elliptical longitudinal direction, as shown in FIG. When manufacturing of the grid is completed, the negative electrode active material is coated on the grid, pressed and cut into a predetermined size to prepare a negative electrode plate. As shown in FIG. 3, the positive electrode plate, the negative electrode plate, and the separator are wound in spiral form using a mandrel winding process centering on the winding axis around which the separator is wound between the negative electrode plate and the positive electrode plate including the grid. Form wealth. Then, the electrolyte is injected into the case, and the cap assembly is attached to the upper shaft opening of the pole plate and the separator assembled in the wound state to manufacture a wound electrode plate group.

Hereinafter, preferred embodiments of the present invention will be described. However, the following examples are only examples of the present invention showing the constitution and effects of the present invention, and the present invention is not limited to the following examples.

Example 1

Cylindrical nickel-metal hydride batteries as a kind of wound electrode plate group were manufactured as follows in accordance with the principles of the present invention. The grid used for the negative electrode plate of the nickel metal hydride battery using an iron plate having a thickness of 0.06 mm is alternately arranged in one row of the negative plate grid punching arrangement in the transverse direction of the elliptical and the next row of the elliptical longitudinal direction as shown in FIG. It was. At this time, the long diameter of the elliptical punching was 2.1 mm and the short diameter was 1.8 mm. After the punching operation was completed, the grid was plated using nickel (Ni), and then the negative electrode active material was applied onto the grid, pressed, and cut into a predetermined size to prepare a negative electrode plate. As shown in FIG. 3, the positive electrode plate, the negative electrode plate, and the separator are wound in spiral form using a mandrel winding process centering on the winding axis around which the separator is wound between the negative electrode plate and the positive electrode plate including the grid. Formed wealth. Then, the electrolyte was injected into the case, and the cap assembly was attached to the upper shaft opening of the pole plate and the separator assembled in the wound state to manufacture the nickel-hydrogen battery of the present invention.

Comparative Example 1

As shown in Fig. 1A, a grid punching arrangement used for the negative electrode plate of the nickel-metal hydride battery was arranged in an elliptical transverse direction using an iron plate having a thickness of 0.06 mm. At this time, the long diameter of the elliptical punching was 2.1 mm and the short diameter was 1.8 mm. After the punching operation was completed, the grid was plated using nickel (Ni), and then the negative electrode active material was applied onto the grid, pressed, and cut into a predetermined size to prepare a negative electrode plate. As shown in FIG. 3, the positive electrode plate, the negative electrode plate, and the separator are wound in spiral form using a mandrel winding process centering on the winding axis around which the separator is wound between the negative electrode plate and the positive electrode plate including the grid. Formed wealth. Then, an electrolyte was injected into the case, and a cap assembly was attached to the upper shaft opening of the pole plate and the separator assembled in the wound state to manufacture a nickel hydride battery.

Comparative Example 2

As shown in Fig. 1B, a grid was prepared using a steel plate having a thickness of 0.06 mm using a round shape of grid punching used for the negative electrode plate of the nickel metal hydride battery as a diameter of 1.0 mm. After the punching operation was completed, the grid was plated using nickel (Ni), and then the negative electrode active material was applied onto the grid, pressed, and cut into a predetermined size to prepare a negative electrode plate. As shown in FIG. 3, the positive electrode plate, the negative electrode plate, and the separator are wound in spiral form using a mandrel winding process centering on the winding axis around which the separator is wound between the negative electrode plate and the positive electrode plate including the grid. Formed wealth. Then, an electrolyte was injected into the case, and a cap assembly was attached to the upper shaft opening of the pole plate and the separator assembled in the wound state to manufacture a nickel hydride battery.

Table 1 shows the results of comparing the characteristics of the batteries produced by the methods of Examples and Comparative Examples of the present invention.

As shown in Table 1 above, when the cylindrical nickel-metal hydride battery is manufactured as a kind of winding electrode group using the method of the embodiment of the present invention, the battery is prevented from shorting and cracking, unlike the conventional cylindrical nickel-metal hydride battery. It was found that the internal pressure can be reduced, the capacity and life of the battery can be greatly increased, and as a result, the effect of increasing the yield of the battery by about 99% or more can be obtained.

Claims (3)

Grid for cathode plates in which elliptical longitudinal and elliptical transverse punching arrangements are alternately arranged one by one. The grid according to claim 1, wherein the elliptical punching has a long diameter of 2.0 to 2.2 mm and a short diameter of 1.7 to 1.9 mm. The grid according to claim 1 or 2, wherein the grid is used in a wound plate group battery.