KR19980021065A - Winding pole plate group in which upper part of positive plate is welded - Google Patents

Abstract

The winding electrode plate group manufactured by the method of welding the upper end of the positive electrode plate can prevent voltage drop and capacity decrease by smoothing electrical contact even when a crack occurs in the positive electrode plate during the winding process.

Description

Winding pole plate group in which upper part of positive plate is welded

[Industrial use]

The present invention relates to a winding electrode plate group in which the upper end of the positive electrode plate is welded, and more particularly, cracks are formed in the positive electrode plate in the process of winding the positive electrode plate by welding both surfaces of the upper end of the positive electrode plate of the winding electrode plate group. The present invention relates to a wound electrode plate group in which an upper end portion of a positive electrode plate, which can prevent voltage drops and capacity drops by smoothing electrical contact even when it occurs.

[Prior art]

The wound electrode plate group is a generic name for a product produced by winding the electrode plate and the separator in a spiral shape, and batteries, electrolytic capacitors and the like are representative examples thereof. In the following description, a battery which is a representative winding electrode plate group will be described as an example.

As portable electronic devices such as cameras, camcorders, portable CD players, portable radio / recorders, laptops, computers, pagers, or mobile phones become more popular, 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.

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. 5 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.

Referring to the charging and discharging reaction of the cylindrical nickel-hydrogen battery as described above in detail.

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

Positive _{electrode: Ni (OH) 2 + OH} - NiOOH + H ₂ O

charge

Discharge

Cathode: M + H ₂ O MH + OH ^-

charge

Discharge

M + 2NiOOH MH + ₂ Ni (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.

The manufacturing method of the winding electrode plate group containing the cylindrical nickel hydride battery which has such a function and structure is as follows. First, the positive electrode active material slurry is coated, dried, and rolled on a metal support to prepare a positive electrode plate, and the negative electrode active material slurry is coated, dried, and rolled onto a metal support to prepare a negative electrode plate, and then a separator is interposed between the positive electrode plate and the negative electrode plate. After winding, the electrode plate and the separator assembly assembled in the wound state are inserted into the can, and the electrolyte is injected and manufactured by attaching the cap assembly to the upper opening. As can be seen in FIG. 1, the conventional positive electrode plate 15 of the wound electrode plate group has a structure in which the positive electrode tab 11 is attached to the upper end of the plate and the tab taping 13 is formed, or as shown in FIG. As shown in the figure, the anode tab is attached to the upper end of the positive electrode plate and tap taping, and then the step welding 21 is formed on one surface of the upper end of the plate. However, in the winding electrode plate group which does not perform tap welding or performs tap welding only on one side of the positive electrode plate, a crack occurs in the positive electrode plate in the process of winding the positive electrode plate, resulting in poor electrical contact. There is a problem of producing a defective product by causing a deterioration phenomenon.

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 improve the electrical contact of the winding electrode plate group, and consequently winding, which can improve the capacity, life and yield of the wound electrode plate group To provide a plate group.

(A) of FIG. 1 is a top view of a positive electrode plate with a positive electrode tab and tab taping attached to an upper end of a conventional positive electrode plate, and (b) is a front view of (a).

(A) of FIG. 2 is a plan view of the positive electrode plate which attached the positive electrode tab and tab taping to the upper end of the conventional positive electrode plate, and welded one side of the positive electrode plate, (b) is the front view of (a).

3 is a plan view of a positive electrode plate having a positive electrode tab and tab taping attached to an upper end of a positive electrode plate and welding both sides of the positive electrode plate according to one embodiment of the present invention, and (b) is a front view of (a).

Figure 4 is a cross-sectional view of the electrode portion of the winding electrode plate group during the operation of winding the positive electrode plate and the negative electrode plate welded on both sides of the upper end of the positive electrode plate according to an embodiment of the present invention.

5 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 *

11.anode tab

13. Tap Taping

15. Positive plate

21. and 31. tap welding

41. Separator

43. Negative plate

In order to achieve the object of the present invention as described above, the present invention is a positive electrode plate, a negative electrode plate, a positive electrode terminal, a negative electrode terminal, a wound electrode plate group including a separator and an electrolyte provided between the positive electrode plate and the negative electrode plate, the upper end of the positive electrode plate It provides a wound electrode plate group characterized in that welding both sides of. Here, it is preferable to use a laser for said welding, and it is preferable that said winding electrode plate group is chosen from a battery or an electrolytic capacitor.

EXAMPLE

Representative Example

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

As shown in (a) and (b) of FIG. 3, the positive electrode tab of the wound electrode plate group is manufactured by attaching and taping the positive electrode tab to the upper end of the positive electrode plate and welding both sides of the upper end of the positive electrode plate. Such welding may use a conventional welding method such as welding using a laser.

As shown in FIG. 4, 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 positive electrode plate and the negative electrode plate prepared above. Form. 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 positive electrode tab was attached to the upper end of the positive electrode plate and taped, and then welded using a laser on both sides of the upper part of the positive electrode plate.

An electrode part was formed by winding these positive electrode plates, negative electrode plates and separators in a spiral shape using a mandrel winding process centering around a winding shaft on which the separator is wound between the positive electrode plate and the negative electrode plate. 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 prepare a nickel hydride battery as the wound electrode plate group of the present invention.

Comparative Example 1

The positive electrode tab was attached to the upper end of the positive electrode plate and taped to prepare a positive electrode plate.

An electrode part was formed by winding these positive electrode plates, negative electrode plates and separators in a spiral shape using a mandrel winding process centering around a winding shaft on which the separator is wound between the positive electrode plate and the negative electrode plate. 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 prepare a nickel-hydrogen battery as the wound electrode plate group.

Comparative Example 2

The positive electrode tab was attached to the upper end of the positive electrode plate and taped, and then welding was performed on one surface of the positive electrode plate using a laser.

An electrode part was formed by winding these positive electrode plates, negative electrode plates and separators in a spiral shape using a mandrel winding process centering around a winding shaft on which the separator is wound between the positive electrode plate and the negative electrode plate. 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 prepare a nickel-hydrogen battery as the wound electrode plate group.

When manufacturing a cylindrical nickel-metal hydride battery as a kind of winding plate group using the method of Example 1 above, the battery was reduced by minimizing the voltage drop or capacity drop of the battery as compared with the case of manufacturing the battery by the method of Comparative Examples 1 and 2. The capacity and yield were improved by about 20% or more, and the lifespan was also improved.

Claims (3)

In the wound electrode plate group including a positive electrode plate, a negative electrode plate, a positive electrode terminal, a negative electrode terminal, a separator and an electrolyte provided between the positive electrode plate and the negative electrode plate, A winding electrode plate group, characterized in that welding both sides of the upper end of the positive electrode plate. The wound electrode group according to claim 1, wherein the welding is performed using a laser. The winding electrode plate group according to claim 1 or 2, wherein the winding electrode plate group is a battery or an electrolytic capacitor.