KR100984463B1 - The cylindrical storage battery - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical storage battery, comprising: a battery case having an opening that also serves as an external terminal of a negative electrode, a cap assembly that is a sealing body for sealing the opening, and a battery case including the battery case and the cap assembly. In the cylindrical storage battery provided with a positive and negative electrode power generation means, a positive and negative electrode current collector connected to each end of the positive and negative electrodes of the power generation means, and a current collector lead for connecting the positive electrode current collector and the cap assembly, The current collector lead uses two current collector lead components including a collector part welded to the positive electrode current collector, a lower weld part welded to the lower part of the cap assembly, and a square plate portion connecting the collector part and the lower weld part. 2 pieces of the current collecting lead parts to be welded to the rectangular plate upper portions, and the overlapped collector portions and the lower welded portions Each is one another to form air bend so as to be vertical in the other direction.

According to the present invention, it is also possible to reduce the resistance according to the reduction of the distance between the connection structure between the battery when the module configuration of a plurality of cylindrical batteries, and to ensure durability against external vibration and impact by installing a plurality of welding points In addition to contributing to the performance and reliability of the battery, it is also possible to secure welding quality for reducing the resistance and to suppress an increase in the defective rate of the assembly process.

Cylindrical Battery, Current Collecting Lead

Description

Cylindrical Storage Battery {THE CYLINDRICAL STORAGE BATTERY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical storage battery, and more particularly, to a current collecting structure in which a current collecting lead derived from a positive electrode is welded to a lower surface of a cap assembly and an upper surface of an electrode body.

Generally, cylindrical batteries, such as a nickel hydride battery, a nickel cadmium battery, and a lithium ion battery, interpose a separator between a positive electrode and a negative electrode, wind them up in a winding phase, and collect a current collector in each end of a positive electrode and a negative electrode, respectively. To form an electrode body, insert the electrode body into a metal battery case having an opening as an outer container, and weld one side of the current collector lead extending from the current collector to a cap assembly which is a sealing body. It is composed by sealing with cap assembly, which is a sealing chain, with an insulating gasket interposed in the opening.

When such a conventional cylindrical storage battery is used for charging and discharging with a large current such as an electric tool, an electric vehicle, and an HEV, the output characteristics are important and the internal resistance of the battery is required for this purpose. In particular, the current collecting lead has a large influence among the components of the battery, and when the resistance generated by the connection of the current collecting lead is large, a large voltage drop due to the electrical resistance occurs, and a problem occurs that the voltage of the battery is lowered.

Figure 1 (a) is a view showing a current collector lead of the conventional cylindrical battery, Figure 1 (b) is a view showing a cylindrical battery combined with the current collector lead of Figure 1 (a).

As shown in FIG. 1, the current collector lead 70 is an integrated body consisting of a circular collector portion 71 welded to a positive electrode current collector of a cylindrical battery, and a square plate portion 72 welded to a lower portion of a cap assembly. The welding part on the 71 side was welded a lot, and the welding part on the square plate upper part 72 welded several points. In the collector portion 71 of the current collector lead, a vent hole 73 for preventing a pressure increase inside the battery, or a slit 74 or a perforation 71a to facilitate the welding of the collector portion with the positive electrode current collector. Installed.

However, such a conventional cylindrical battery has a small welding area between the rectangular plate upper portion 72 of the current collecting lead 70 and the lower portion of the cap assembly in high current charge / discharge applications, and current flows through the rectangular plate upper portion 72 of the current collecting lead. Since there is a high electrical resistance problem. In addition, when the welded part is damaged by an external impact, there is a problem that the performance of the battery is reduced.

The present invention has been made in view of the above-described problems in the prior art, and in the prior art, the welding area is increased by increasing the welding area of the upper pole group and the collector lead collector portion and improving the lower weld portion of the collector lead under the cap assembly. It is an object of the present invention to provide a cylindrical storage battery that can reduce the electrical resistance through the increase of, and the improvement of weldability, and can improve the reliability of the battery performance against external impact.

Cylindrical storage battery according to the present invention in order to achieve the above object,

A battery case having an opening serving as an external terminal of the negative electrode, a cap assembly which is a sealing body sealing the opening, a power generation means for positive and negative electrodes inserted into a battery container including the battery case and the cap assembly; In the cylindrical storage battery provided with a positive and negative electrode current collector connected to the ends of the positive and negative electrodes of the power generating means, and a current collector lead for connecting the positive electrode current collector and the cap assembly,

The current collector lead,

The current collector using two current collector lead components including a collector portion welded to the positive electrode current collector, a lower weld portion welded to a lower portion of the cap assembly, and a rectangular plate portion connecting the collector portion and the lower weld portion; The two lead parts are superimposed and welded to the rectangular plate portions, and the folded collector portions and the lower weld portions are formed to be bent so as to be perpendicular to each other in different directions.

Here, the length of the side that meets the collector portion and the lower welded portion in the rectangular plate portion is preferably smaller than the length of the opening diameter of the battery case.

In addition, the collector part and the lower weld part are formed with a vent hole for adjusting the pressure in the battery.

Shapes of the collector portion and the lower welding portion of the current collector lead have a circular or polygonal shape within the size of the opening of the battery case.

Further, the welding is made of electric resistance welding or laser welding.

In addition, the collector portion of the current collector lead part is preferably formed with perforations or slits.

In addition, the current collector lead parts may be formed to have a large thickness by overlapping a plurality.

In addition, the current collecting lead is made of any one of nickel, nickel plated steel, copper, nickel plated copper, copper plated steel, copper plated nickel, or aluminum.

According to the present invention as described above, the resistance at the time of high current energization due to the increase in the welding area of the pole group of the power generating means inside the battery case and the collector lead collector portion, and the weld area through the improvement of the lower weld portion of the collector lead in the lower cap assembly. This can be reduced, and in particular, when the module is composed of a plurality of cells, it is also possible to reduce the resistance due to the reduction in the energization distance with the inter-cell connection structure.

In addition, installation of a large number of welding points can improve the reliability of battery performance against external impact.

Furthermore, the work of the welding process and the assembly process can be improved by improving the weldability of the collector portion of the current collector lead and the upper portion of the positive electrode current collector and the lower part of the cap assembly and the lower weld portion of the current collector lead.

Hereinafter, embodiments of the cylindrical storage battery configured as described above will be described in detail with reference to the accompanying drawings.

FIG. 2 is a cross-sectional view of a cylindrical storage battery to which a current collector lead is applied according to an embodiment of the present invention, and FIG. 3 is an exploded perspective view of a cylindrical storage battery to which a current collector lead is applied according to an embodiment of the present invention, and FIG. a) is a view showing a current collecting lead component according to an embodiment of the present invention, Figure 4 (b) is a side view of the current collecting lead combined the two current collecting lead parts of Figure 4 (a), Figure 4 (c) Figure is a perspective view of a current collector lead according to an embodiment of the present invention.

As shown in FIG. 2, the cylindrical storage battery to which the current collecting lead according to the present invention is applied includes a battery case 10 having an opening serving as an external terminal of the negative electrode 6, and a cap assembly which is a sealing body sealing the opening. 50, power generation means of positive and negative electrodes inserted into a battery container including the battery case 10 and the cap assembly 9, and end portions of the positive and negative electrodes of the power generation means. A positive and negative electrode current collector (not shown) connected to each other, and a current collector lead (30 in FIG. 3) connecting the positive electrode current collector and the cap assembly 9 are provided. Here, the separator 7 which distinguishes between the positive 8 and the negative 6 poles of the power generating means is also included.

As shown in FIG. 3, the current collector lead 30 includes a collector portion 34 welded to a positive electrode current collector (not shown) located at an opening side, which is an upper end of the battery case 30, and a cap assembly 50. Current collecting is carried out using two current collecting lead parts (32 in FIG. 4) composed of a lower welding part 36 welded to the lower part and a square plate-shaped part 38 connecting the collector part 34 and the lower welding part 36. Two lead parts 32 are overlapped, and the square plate-shaped parts 38 are welded, and the folded collector parts 34 and the lower welded parts 36 are bent so as to be perpendicular to each other in different directions.

At this time, since the square plate portion must be insulated from the battery case, the length of the side that meets the collector portion 34 and the lower welding portion 36 in the square plate portion 38 is smaller than the length of the opening diameter of the battery case 10. It is preferable.

In addition, the collector 34 and the lower welding part 36 of the current collecting lead 30 are formed with a vent hole 40 for controlling the pressure in the battery.

Here, the shape of the collector portion 34 and the lower welding portion 36 of the current collecting lead 30 may have a circular or polygonal shape in consideration of the welding area within the size of the opening of the battery case 10.

The welding also consists of electrical resistance welding or laser welding.

Thus, after charging the electrode body, which is a power generation means having a cap assembly and a positive electrode current collector welded to the current collector lead 30, the gasket is installed inside the can and sealed.

As described above, by welding a plurality of current collector leads 30 to the lower portion of the cap assembly 50 and the positive electrode current collector, it is possible to easily conduct a large current through the expansion of the current carrying area, thereby reducing the electrical resistance. The reliability of the battery performance can be improved by reducing the possibility of weld breakage and battery performance degradation due to external impact caused by welding.

At this point, the current collector lead will be described in more detail.

As shown in FIG. 4A, a collector portion 34 welded to the positive electrode current collector, a lower weld portion 36 welded to the lower portion of the cap assembly, and a square connecting the collector portion 34 and the lower weld portion 36 to each other. Two collector lead parts 32 made of the plate portion 38 are used. That is, as shown in FIG. 4 (b), two current collector lead parts 32 are stacked to weld the rectangular plate upper parts 38 to each other, and the folded collector parts 34 are bent to be perpendicular to each other in the same direction as the arrow direction. Similarly, the lower welds 36 are also bent so as to be perpendicular to each other in a different direction as shown in Fig. 4 (c).

At this time, the shape of the collector portion 34 and the lower welding portion 36 of the current collector lead part 32, when the two current collector lead parts 32 are combined to form an integrated current collector lead 30, the battery case ( In order to secure a wider welding area within the size of the opening of 10), it is preferable to have a semi-circular shape to form a circle, or may have various shapes other than semicircle to form a polygonal shape.

As such, the thickness of the upper and lower portions of the current collecting lead connecting the lower portion of the cap assembly 50 and the positive electrode current collector of the electrode body, which is the power generating means, is increased while doubling the thickness, thereby improving welding characteristics. It may also be possible to improve the high current conductance.

Here, the collector 34 of the current collector lead part 32 of FIG. 4 may include perforations or slits as in the prior art of FIG. 1 so that the electrolyte solution impregnation and welding may be more easily performed.

In addition, the current collector lead part 32 may form a thick thickness of the current collector lead part by overlapping a plurality of thin current collector lead parts 32 in order to further reduce resistance.

In addition, the current collecting lead may be applied to various materials having low electrical resistance such as nickel, nickel plated steel, copper, nickel plated copper, copper plated steel, copper plated nickel, or aluminum.

The above embodiment is an example in which one example of the shape of the current collecting lead of the present invention is applied, and various applications such as shape, material, and thickness of the current collecting lead 30 are possible.

In this embodiment and the comparative examples of the prior art, both are nickel-metal hydride batteries, including a positive / negative electrode, a separator, a current collector lead, a gasket, a cap assembly, a battery case (or a can), and an assembly process. All manufacturing processes proceed in the same way.

The positive electrode is manufactured by cutting Foam Ni to a predetermined size, rolling it to a certain thickness, and then applying and drying the positive electrode paste.The negative electrode is cut to a predetermined size after cutting NPPS (Nickel Plated Pored Steel) into a predetermined size, and then rolled to a certain thickness. The negative electrode paste is applied and dried to produce it.

Between the positive electrode and the negative electrode, the electrode body is formed in a wound state through a separator, and an upper end of the electrode body is exposed with an end of a Ni ribbon welded to Foam Ni, which is a positive electrode, and an end of NPPS, which is a negative electrode, is exposed on a lower surface. . The negative electrode collector is subjected to electrical resistance welding to weld a predetermined number of times.

As described above, the electrode body is formed, and then electrical resistance welding or laser welding is performed by applying the current collecting lead according to the present invention.

5 is a graph showing a voltage-current (V-I) characteristic curve of one embodiment of the present invention and a comparative example thereof.

As an embodiment of the present invention, the material of the current collector lead 30 is made of nickel, and the thickness of the current collector lead part 32 is 0.3 mm, and the size of the collector part 34 which is the electrode side disc is 28 mm in diameter and a cap. The lower welding part 36, which is the lower welding side disk of the assembly 50, has a dimension of 23 mm, and the square plate upper part 38 which connects each disk has 20 mm of each side, and, as a comparative example, a conventional current collector lead Applying an example, the material of the current collector lead subjected to electrical resistance welding at a predetermined number of welding times is nickel, the thickness of the current collector lead is 0.3 mm, the size of the electrode side plate is 28 mm in diameter, and the square width of the welding side under the cap assembly is 12 mm. In each case, the same predetermined chemical conditions and activation conditions are performed after assembling, and then three comparative tests are performed to obtain the results as shown in the drawing. At this time, the test method is charged for 15 hours at 0.1C, then discharged for 10 seconds at 1 / 3C, 1C, 5C, 10C, each 10 seconds voltage is measured in each step, and the battery voltage after 10 to the vertical axis in the graph Then, VI characteristics are obtained based on the horizontal axis of each current value.

That is, as shown in Figure 5, it can be seen that the inclination of the straight line of the V-I characteristic curve of the cylindrical storage battery to which the embodiment according to the present invention is applied is smaller than the comparative example. From this, it can be seen that the operating voltage of the storage battery of the embodiment according to the present invention is higher than that of the comparative example, and the internal resistance is low.

This is due to the reduction of the internal resistance due to the conductive path shortened by the current collecting lead of the cylindrical battery of one embodiment according to the present invention, which may indicate excellent high rate discharge characteristics.

In the above, the present invention has been described with reference to the drawings and embodiments, but the present invention is not limited to the specific embodiments, and those skilled in the art can make many modifications and variations without departing from the scope of the present invention. I will understand what is possible.

1 (a) is a view showing a current collecting lead of a conventional cylindrical battery.

Figure 1 (b) is a view showing a cylindrical battery coupled to the current collector lead of Figure 1 (a).

Figure 2 is a view showing a cross-sectional view of a cylindrical storage battery is applied to the current collector lead of one embodiment of the present invention.

Figure 3 is an exploded perspective view of a cylindrical storage battery is applied to the current collector lead according to an embodiment of the present invention.

Figure 4 (a) is a view showing a current collector lead component according to an embodiment of the present invention.

Figure 4 (b) is a side view of the current collector lead to combine the two current collector lead parts of Figure 4 (a).

Figure 4 (c) is a view showing a perspective view of the current collector lead according to an embodiment of the present invention.

5 is a graph showing a voltage-current (V-I) characteristic curve of one embodiment of the present invention and a comparative example thereof.

Description of the Related Art

6 negative electrode 7 separator 8 positive electrode

10: battery case 30: current collector lead 32: current collector lead parts

34, 71: collector portion 36: lower weld portion

38: square plate upper part 40, 73: vent hole

50: cap assembly 70: conventional collector lead

72: conventional square plate upper portion 74: slit 71a: perforation

Claims (10)

A battery case having an opening serving as an external terminal of the negative electrode, a cap assembly which is a sealing body sealing the opening, a power generation means for positive and negative electrodes inserted into a battery container including the battery case and the cap assembly; In the cylindrical storage battery provided with a positive and negative electrode current collector connected to the ends of the positive and negative electrodes of the power generating means, and a current collector lead for connecting the positive electrode current collector and the cap assembly, The current collector lead, The current collector using two current collector lead components including a collector portion welded to the positive electrode current collector, a lower weld portion welded to a lower portion of the cap assembly, and a rectangular plate portion connecting the collector portion and the lower weld portion; Two lead parts are superimposed and welded on the rectangular plate portions, and the folded collector portions and the lower weld portions are bent so as to be perpendicular to each other in different directions, The length of the side that meets the collector portion and the lower welded portion on the rectangular plate portion is smaller than the length of the opening diameter of the battery case, Shapes of the collector portion and the lower welding portion of the current collector lead has a circular or polygonal shape within the size of the opening of the battery case, And the collector portion is welded to the positive electrode current collector by a plurality of weldings, and the lower welding portion is welded to a lower portion of the cap assembly by a plurality of weldings, thereby expanding a current carrying area. delete The method of claim 1, The collector and the lower welding portion is a cylindrical storage battery, characterized in that the vent hole (Venthole) is formed to adjust the pressure inside the battery. delete The method according to claim 1 or 3, The welding is a cylindrical storage battery, characterized in that consisting of electrical resistance welding or laser welding. The method according to claim 1 or 3, The collector portion of the current collector lead component is a cylindrical storage battery, characterized in that the perforations or slits are formed. delete The method according to claim 1 or 3, The current collector lead is made of any one of nickel, nickel plated steel, copper, nickel plated copper, copper plated steel, copper plated nickel, or aluminum. A battery case having an opening serving as an external terminal of the negative electrode, a cap assembly which is a sealing body sealing the opening, a power generation means for positive and negative electrodes inserted into a battery container including the battery case and the cap assembly; In the cylindrical storage battery provided with a positive and negative electrode current collector connected to the ends of the positive and negative electrodes of the power generating means, and a current collector lead for connecting the positive electrode current collector and the cap assembly, The current collector lead, The current collector is formed by using a plurality of current collector lead components including a collector part welded to the positive electrode current collector, a lower weld part welded to a lower part of the cap assembly, and a square plate portion connecting the collector part and the lower weld part. Overlapping a plurality of lead parts are welded to the rectangular plate upper portion, and bent to form a nested collector portion and the lower welding portion to be perpendicular to each other in a different direction, Shapes of the collector portion and the lower welding portion of the current collector lead has a circular or polygonal shape within the size of the opening of the battery case, And the collector part is welded to the positive electrode current collector by a plurality of welding parts, and the lower welding part is welded to a lower part of the cap assembly by a plurality of welding parts, thereby expanding a current carrying area. 10. The method of claim 9, The collector portion and the lower welding portion is a cylindrical storage battery, characterized in that the vent hole (Venthole) is formed to adjust the pressure inside the battery.

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