KR100217712B1 - Electrode for cell and its method - Google Patents

Abstract

Melting the metal used for binding the active material with a melting point lower than that of the active material, mixing the molten metal with the active material The preliminary composition for the electrode plate is prepared by stirring the preliminary composition, and the preliminary composition is cooled while the preliminary composition is cooled. The electrode plate produced by working the plate in the form of an electrode plate can sufficiently prevent the separation between the active materials, The life and capacity of the electrode can be increased, corrosion and swelling of the electrode can be prevented, manufacturing cost can be saved, and manufacturing cost can be saved because it is manufactured through a simple process.

Description

Electrode Plate and Manufacturing Method Thereof

[Industrial Applications]

The present invention relates to an electrode plate for use in a battery and a method of manufacturing the same, and more particularly, to a method of manufacturing an electrode plate using a metal melting material at a lower temperature than an active material used for an electrode plate, And more particularly, to an electrode plate and a method for manufacturing the same, which exhibit a high lifetime, a high charge / discharge rate, an increase in capacitance, an improvement in binding force between active materials and an excellent pressure resistance characteristic by innovatively reducing the resistance.

BACKGROUND ART [0002]

Various portable electronic devices such as a camera, a camcorder, a portable CD player, a portable radio / recording player, a notebook, a computer, a wireless pager or a portable telephone have been actively used and demanded for high capacity and long life .

Thus, a battery having a wide use field and a high demand is used to convert chemical energy into electrical energy using a difference in contact potential between appropriate materials. The technical classification of a battery includes a primary battery in which only a discharge for converting chemical energy into electric energy is performed, a secondary battery in which discharging and charging can be repeated, a fuel for converting the combustion heat of hydrocarbon into electricity Batteries, and solar cells that convert light energy into electrical energy. Further, the battery can be classified into an alkaline battery, a solid electrolyte battery, and a nonaqueous electrolyte battery according to the constitution of the electrolytic solution. The battery can be classified into a cylindrical battery, a button battery, and a coin battery depending on the appearance of the battery.

A double cylindrical (jelly-roll type) battery will be described as an example. A battery having a cylindrical structure is a kind of a winding electrode plate group, which is a battery which discharges current composed of an anode and a cathode, a separator for preventing short-circuiting thereof, an electrolyte, and a cathode terminal and a cathode terminal. A more detailed structure of these will be described by taking a nickel-hydrogen battery shown in FIG. 3 as an example.

The cylindrical nickel-metal hydride battery includes a positive electrode plate 15 in which Ni (OH) ₂ is coated with a positive electrode active material, and a negative electrode plate 15 in which a negative electrode active material mainly composed of LaNi ₄ , MmNi ₅ , Ti- A separator 41 made of a nonwoven fabric and a cellophane tape or the like to prevent a short circuit between the positive electrode plate 43 and the positive electrode plate 15 and the negative electrode plate 43 and a cap 56 as a positive electrode terminal and a negative electrode terminal, And also includes a safety valve 55, a stopper plate 53, an insulating ring 51, and an insulating plate 59. In addition,

The charging and discharging reaction of the above cylindrical nickel-metal hydride battery will be described in detail as follows.

The hydrogen storage alloy formed by decomposing water in the electrolyte when the anode active material is made of a hydrogen storage alloy, the positive electrode active material is made of nickel hydroxide and the electrolytic solution is made of potassium hydroxide (KOH) aqueous solution is stored and discharged The necessary hydrogen is discharged into the electrolytic solution and discharged. The charging and discharging reaction equations are as follows.

In the above reaction formula, M represents a hydrogen storage alloy capable of absorbing and desorbing hydrogen ions, and includes AB ₅ system using a rare earth element and AB ₂ system using Ti, Zr, V and the like. In the above equation, the positive and negative electrodes of the nickel metal hydride battery are capable of charging and discharging several hundred times or more in accordance with the above-described reaction formula.

A manufacturing method of a winding electrode plate group including a cylindrical nickel-metal hydride battery having such a function and structure is as follows. First, a positive electrode plate is prepared by applying a positive electrode active material slurry on a metal support, drying and rolling the negative electrode active material slurry, coating the negative electrode active material slurry on a metal support, drying and rolling to prepare a negative electrode plate, And a step of inserting the electrode plate and the separator assembly assembled in the wound state into the can, injecting the electrolyte, and mounting the cap assembly on the upper opening.

As shown in the above description and FIG. 1, the conventional positive electrode plate and negative electrode plate are coated with the active material paste on the active material support 3 in order to prevent the active material 2 from coming off. An organic binder (1) is used to enhance binding between the metal support and the active material. In order to improve the viscosity of the paste, a thickening agent is used, a dispersing agent and defoaming agent are added to suppress foaming, And another conductive agent is added to recover the conductivity due to the addition of the binder. However, in order to prevent the active material from escaping, there is a problem that the conductivity is lowered to a certain degree even if various additives such as those listed above are added. Further, the capacity is lowered due to the addition of the additives, and there are problems such as corrosion and swelling of the electrode, and the manufacturing process is complicated and the cost is increased.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the problems of the prior art as described above, and it is an object of the present invention to sufficiently prevent the detachment of the active materials and to reduce the internal resistance by improving the conductivity, And a method of manufacturing the same, which can be manufactured through a simple process that can prevent corrosion and expansion of electrodes and save manufacturing cost.

1 is a cross-sectional view schematically showing an electrode plate used in a conventional wind-up electrode plate group cell.

FIG. 2 is a cross-sectional view schematically showing an electrode plate used in a winding electrode plate group battery according to an embodiment of the present invention. FIG.

FIG. 3 is a schematic exploded view showing the structure of a nickel-metal hydride battery, which is a kind of wind pole plate group cell.

DESCRIPTION OF THE REFERENCE NUMERALS

1: organic binder 2: active material

3: active material support 4: metal

In order to achieve the above object, the present invention provides an electrode plate comprising an active material used for providing an electrical activity and a metal having a lower melting point than the active material and fused to the active material. Here, the metal is preferably selected from the group consisting of copper (Cu), zinc (Zn), indium (In), aluminum (Al), magnesium (Mg), and mixtures thereof. (OH) ₂ , AB ₅ hydrogen storage alloy, and AB ₂ hydrogen storage alloy. Here, A is an alloy of rare-earth elements and B is an alloy of elements consisting of Ni, Al, Mn, Co, and the like. The distance between the active material particles is preferably 0.1 to 50 mu m on average, and the electrode plate may be used in a battery selected from the group consisting of a wind-electrode plate group battery, a button battery, and a coin-type battery.

The present invention also provides a preliminary composition for an electrode plate having a melting point lower than that of an active material, melting a metal used for binding the active material, mixing the active metal with the molten metal and stirring the preliminary composition, And cooling and shaping the plate into a shape of an electrode plate. Here, the step of heating and stirring the preliminary composition is preferably carried out in an inert or vacuum atmosphere.

[Example]

[Representative Embodiment]

A process for manufacturing an anode plate of a nickel-metal hydride battery, which is a kind of wind pole plate group cell, according to the principles of the present invention will now be described in order to test the effects of the present invention.

An active material used for a negative electrode plate of a nickel metal hydride battery, that is, a metal having a lower melting point than a hydrogen storage alloy is melted. The powdery metals that can be used are excellent in stretchability and shrinkability, and can use stable metals in electrolytic solutions, such as copper, zinc, indium, aluminum, magnesium, and mixtures thereof. The active material is mixed with the molten metal and uniformly stirred to prepare a preliminary composition for an electrode plate. In this case, the mixing and stirring process is performed in an inert atmosphere or a vacuum atmosphere. When stirring is carried out uniformly, the active material 2 is distributed in the molten metal 4 as shown in FIG. In order for the active material to exhibit sufficient activity, the average distance between the active material particles is suitably from 0.1 to 50 mu m, and this distance can be controlled by the amount of the metal to be mixed with the active material. The preliminary composition after completion of the stirring is rapidly cooled or stepwise cooled to prepare a negative electrode plate for use in a nickel-metal hydride battery through a process such as cutting.

[Preferred Embodiment]

Preferred embodiments and comparative examples of the present invention will be described. However, the following embodiments are only examples of the present invention showing the structure and effects of the present invention, and the present invention is not limited to the following embodiments.

[Example 1]

90 g of MmNi _3.55 Al _0.3 Mn _0.4 Co _0.75 was mixed with 10 g of the molten copper solution in a vacuum state as a hydrogen storage alloy and uniformly stirred to prepare a preliminary composition for a negative electrode plate of a nickel hydride battery. The preliminary composition that had been stirred was cooled stepwise and rolled and cut to obtain a negative electrode plate for use in the nickel hydrogen battery of the present invention.

[Example 2-5]

A negative electrode plate for use in the nickel hydrogen battery of the present invention was prepared in substantially the same manner as in Example 1, except that zinc, indium, aluminum, and magnesium were used instead of copper as the metal.

[Comparative Example 1]

An active material support for a nickel metal hydride battery, which is commonly used by forming a hole in steel after nickel plating, is prepared, and then a slurry obtained by mixing an active material, an additive such as an organic binder, a conductive agent, a thickening agent, a dispersant, A negative electrode plate for a nickel hydride battery was produced through a cutting process.

As a result of preparing the nickel-metal hydride battery using the anode plate manufactured by the method of the embodiment of the present invention and the comparative example, the manufacturing method was much simpler since the method of the embodiment did not require the use of various additives. By reducing the internal resistance of the battery, it has been confirmed that the battery has a high lifetime, a high charging / discharging capacity, an increased capacity, an improved bonding force between the active materials, and excellent pressure resistance characteristics.

Claims (9)

Ni (OH) ₂ , AB ₅ system hydrogen storage alloy and AB ₂ system hydrogen storage alloy (wherein A is an alloy of a recrystallization element, and B is an element selected from the group consisting of Ni, Al, An active material selected from the group consisting of copper, copper, and alloys thereof, which is used to provide electrical activity; And a metal having a melting point lower than that of the active material and fused to the active material; Lt; / RTI > The plate according to claim 1, wherein the metal is selected from the group consisting of copper, zinc, indium, aluminum, magnesium, and mixtures thereof. 2. The electrode plate according to claim 1, wherein the active material particles have an average distance of 0.1 to 50 mu m. The electrode plate according to any one of claims 1 to 3, wherein the electrode plate is used for a battery selected from the group consisting of a winding electrode plate group battery, a button battery, and a coin battery. Melting the metal having a melting point lower than that of the active material and used for binding the active material; Mixing the molten metal with the active material and stirring the molten metal to prepare a preform for a polar plate; And a step of cooling the preliminary composition after the stirring to form an electrode plate while cooling it. 6. The method of claim 5, wherein the metal is selected from the group consisting of copper, zinc, indium, aluminum, magnesium, and mixtures thereof. 6. The method according to claim 5, wherein the active material is selected from the group consisting of Ni (OH) ₂ , AB ₅ hydrogen storage alloy and AB ₂ hydrogen storage alloy, wherein A is an alloy of phytate- Wherein B is an alloy of elements selected from the group consisting of Ni, Al, Mn, and Co. 6. The method of manufacturing an electrode plate according to claim 5, wherein the distance between the active material particles is 0.1 to 50 mu m on average. The method for producing an electrode plate according to claim 6, wherein the step of heating and stirring the preliminary composition is performed in an inert or vacuum atmosphere.