Title of invention: secondary battery and its manufacturing method
Technical field
[One]
This application claims the benefit of priority based on Korean Patent Application No. 10-2018-0078966 filed on July 6, 2018, and all contents disclosed in the documents of the corresponding Korean patent applications are included as part of this specification.
[2]
The present invention relates to a secondary battery and a manufacturing method thereof, and more particularly, to a button-type secondary battery capable of increasing capacity by mounting a larger electrode assembly by increasing an internal space, and a manufacturing method thereof.
[3]
Background
[4]
Button-type batteries, which are commonly used as coin-type batteries and button-type batteries, have a thin button shape and are widely used in various devices such as remote controls, watches, toys, and computer parts.
[5]
These button-type batteries were mainly manufactured as non-rechargeable primary batteries, but are widely manufactured as secondary batteries capable of charging and discharging in accordance with the recent development of miniaturized devices. And, like a cylindrical or pouch-type secondary battery, a button-type secondary battery has a structure in which an electrode assembly and an electrolyte are embedded in a case to enable repetitive charging and discharging.
[6]
1 is a cross-sectional view of a conventional button-type secondary battery. As shown, the external appearance of the button-type secondary battery (the appearance combined with the first can and the second can) has a flat cylindrical shape similar to the shape of a chalet, but the inside of the first can 1 with an open upper side When the electrode assembly 4 is mounted on the electrode assembly 4, peripheral parts (not shown) of the electrode assembly 4 are mounted and an electrolyte (including a liquid electrolyte) is injected, and then the upper side of the first can 1 is removed. It is configured to cover two cans (2).
[7]
At this time, clamps 1a and 2a to be fitted to each other are formed on the upper edge portion of the side surface of the first can 1 and the edge portion of the second can 2, respectively. That is, the first can 1 and the second can 2 are bent so that when the second can 2 is placed on the electrode assembly 4, the edges are bent so that the clamps 1a and 2a are respectively Is formed, each of the clamps (1a, 2a) is elastically deformed by the pressure generated when the second can (2) enters, and when the entry of the second can (2) is completed, it is elastically restored as shown in the figure. Fastening is made together.
[8]
In addition, a gasket 3 made of a rubber material for sealing the interior is fitted between the clamps 1a and 2a.
[9]
Detailed description of the invention
Technical challenge
[10]
On the other hand, in the clamping method as above, the height of the inner space between the first can (1) and the second can (2) is lower than the total height (the height from the bottom to the top of the battery), so that the electrode assembly (4) Since the size of the battery is limited, it is difficult to increase the capacity of the battery relative to the total volume of the battery.
[11]
Accordingly, an object of the present invention is to provide a button-type secondary battery (which can mount a larger electrode assembly) and a method for manufacturing the same, by securing an internal space larger than the conventional structure.
[12]
Means of solving the task
[13]
The present invention for achieving the above object provides a button-type secondary battery capable of further increasing the internal space and a method of manufacturing the same.
[14]
The button-type secondary battery according to the present invention includes: a first can having a first side surface vertically formed along a circumference of a first base surface; It has a second base surface having a larger diameter than the first base surface of the first can, and a second side surface is vertically formed along the circumference of the second base surface, and a vent hole is perforated on the second side surface. A second can; And a gasket positioned between the first side surface and the second side surface when the first can and the second can are combined, wherein the first can and the second can have a first side surface inside the second side surface. The first can and the second can are fixed to each other by being coupled to enter the gasket and being deformed to fit the gasket into the vent hole.
[15]
In the present invention, the first side surface of the first can faces upward from the first base surface, the second side surface of the second can faces downward from the second base surface, and the second can is above the first can. Is combined to cover.
[16]
In addition, the gasket is deformed to a size corresponding to a pressure difference between the pressure inside the space formed by the first can and the second can and the pressure outside the first can and the second can.
[17]
In an embodiment of the present invention, at least two or more vent holes may be formed along the circumference of the side surface of the second can.
[18]
For example, the second can may have a disk shape on a plane, and an even number of vent holes may be formed, and each of the vent holes may be arranged to have a symmetrical pair with respect to the center of the disk.
[19]
As another configuration, the second can has a disk shape on a plane, and the vent holes may be arranged to be denser in a specific region than in other regions based on the circumference of the disk shape.
[20]
In addition, the method of manufacturing a button-type secondary battery according to the present invention includes a first can having a first side surface vertically formed along a circumference of the first base surface and a second base surface having a larger diameter than the first base surface. A method of manufacturing a secondary battery in which a second can having a second side surface vertically formed along a circumference of the second base surface is combined, the method comprising: providing the first can; Providing the second can; A perforating step of perforating a vent hole on a side surface of the second can; A coupling step of coupling the first can and the second can so that the gasket is positioned between the side surface of the first can and the side surface of the second can (after the electrode assembly and electrolyte are mounted), and the gasket covers the vent hole; And a fixing step of fixing the first can and the second can by deforming the gasket so that the gasket is fitted into the vent hole.
[21]
In the fixing step, the gasket is deformed to protrude to the outside of the vent hole when negative pressure is applied to the vent hole from the outside.
[22]
In the present invention, it further includes a temporary fixing step of fixing the movement of the first can and the second can before applying the negative pressure to the vent hole.
[23]
Further, a negative pressure is applied while the gasket is attached to the surface of the side surface of the first can.
[24]
In addition, a portion of the gasket to be deformed (so that the side surface of the first can is not deformed) may be attached with a lower adhesive force than other regions, or negative pressure may be applied in the unattached state.
[25]
In addition, some regions of the gasket to be deformed may have different thicknesses than other regions (so that deformation can be caused more easily due to the concentration of sound pressure).
[26]
In the perforating step, at least two or more vent holes may be formed along the circumference of the side surface of the second can.
[27]
Effects of the Invention
[28]
In the present invention having the configuration as described above, the fastening point of the first can and the second can is moved from the top to the side of the battery, so that the height of the internal space relative to the total height can be increased. There is an effect that it is possible to mount an electrode assembly with a larger capacity.
[29]
In the present invention, since the gasket is deformed so as to be fitted into the vent hole to fix the first can and the second can, the first can and the second can can have a smooth surface.
[30]
Since the deformation of the gasket is made in a size corresponding to the difference between the pressure inside the space formed by the first can and the second can and the pressure outside the first can and the second can, it causes stress and/or unnecessary deformation. No physical pressure is applied to the first and second cans.
[31]
Since at least two vent holes may be formed, it is possible to adjust the fastening force according to the required specifications.
[32]
In addition, since the vent holes may be arranged to be denser in a specific area, the fastening force may be further increased at a specific position where an electrode lead or the like is additionally attached.
[33]
In addition, some regions of the gasket to be deformed may be attached with a lower adhesive force than other regions, or negative pressure may be applied in the unattached state so that deformation of the side surface of the first can may not occur.
[34]
In addition, a partial region of the gasket to be deformed may be formed to have a thicker thickness than other regions, so that deformation can be made more easily.
[35]
Brief description of the drawing
[36]
1 is a cross-sectional view showing a simplified longitudinal section of a conventional button-type secondary battery.
[37]
2 is a simplified cross-sectional view showing a longitudinal section of a button-type secondary battery according to an embodiment of the present invention.
[38]
3A is a cross-sectional view illustrating a state before and after a negative pressure is applied in a state in which a second can is seated in the first can, and a deformation occurs on the side surface of the first can together with a gasket.
[39]
3B is a cross-sectional view showing a state before and after a negative pressure is applied in a state in which a second can is seated in the first can, but only the deformation of the gasket occurs.
[40]
4A is a cross-sectional view illustrating a path through which internal air escapes when negative pressure is applied.
[41]
FIG. 4B is a cross-sectional view showing a state in which a gasket in which a region where deformation occurs when a negative pressure is applied is thicker than that of other regions is mounted.
[42]
5 is a bottom view showing regions in which vent holes can be drilled in a second can.
[43]
Mode for carrying out the invention
[44]
Hereinafter, based on the accompanying drawings, the present invention will be described in detail so that those of ordinary skill in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.
[45]
In order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals are attached to the same or similar components throughout the specification.
[46]
In addition, terms or words used in this specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventor appropriately defines the concept of terms in order to describe his own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of ​​the present invention based on the principle that it can be done.
[47]
The present invention provides a button-type secondary battery having a larger internal space than a conventional structure and a method of manufacturing the same, and embodiments of the present invention will be described in more detail below with reference to the accompanying drawings.
[48]
[49]
Example 1
[50]
The present invention provides a button-type secondary battery having an increased internal space compared to the conventional structure as Example 1. The secondary battery of the present invention is characterized in that a gasket 30 disposed between the first can 10 and the second can 20 is inserted into the vent hole 23 formed in the second can 20 to be fixed. .
[51]
2, the first can 10 has a first base surface 11 formed in a circular shape having a predetermined size, and a first side surface 12 along the circumference of the first base surface 11 It has a shape formed vertically. In addition, the second can 20 has a circular second base surface 21 having a larger diameter than the first base surface 11 of the first can 10 and The second side surface 22 is vertically formed along the circumference, and the second side surface 22 has a structure in which a vent hole 23 is perforated. That is, the first can 10 and the second can 20 have a flat cylindrical shape similar to a chalet, but the second can 20 has a slightly larger area, and a vent hole 23 is added. It has a perforated structure.
[52]
In this embodiment, the first side surface 12 of the first can 10 faces upward from the first base surface 11 and the second side surface 22 of the second can 20 is a second base surface. The second can 20 is coupled to cover the top of the first can 10 toward the bottom at (21). At this time, the first can 10 is coupled to the second can 20 in a state in which a gasket 30 (which has a ring shape) is fitted on the outer circumferential surface of the first side surface 12, so that the gasket 30 When the can 10 and the second can 20 are combined, they are positioned between the first side surface 12 and the second side surface 22. For reference, at this time, the gasket 30 may be partially or entirely attached to the first side surface 12 through an adhesive.
[53]
And, in a state in which the first side surface 12 enters the inside of the second side surface 22, the gasket 30 coupled to the outer circumferential surface of the first side surface 12 faces the inner circumferential surface of the second side surface 22. Will do. At this time, since the gasket 30 is exposed through the vent hole 23 formed in the second side surface 22, when a negative pressure is applied to the vent hole 23, a part of the gasket 30 is Deformation is made to fit in (23).
[54]
That is, the gasket has a size corresponding to a pressure difference between the pressure inside the space formed by the first can 10 and the second can 20 and the pressure outside the first can 10 and the second can 20. 30) is deformed, so that the first can 10 and the second can 20 are fixed.
[55]
In addition, in the embodiment of the present invention, the drawings show that there is one vent hole 23, but at least two vent holes 23 may be formed along the circumference of the side surface 22 of the second can 20. I can. For example, the second can 20 has a disk shape on a plane, and as shown in FIG. 5, an even number of the vent holes 23 are formed, each of which is symmetrical with respect to the center of the disk. It can be arranged to have a pair (see i, ii, iii of Fig. 5). For reference, FIG. 5 shows positions where the vent holes 23 can be formed when the second can 20 is viewed from top to bottom or from bottom to top. It is a cross-sectional view of 2 cans.
[56]
As another configuration, the second can 20 has a disk shape on a plane, and the vent hole 23 may be arranged to be denser in a specific region than in other regions based on the circumference of the disk shape ( See iv, v in Fig. 5).
[57]
[58]
Example 2
[59]
[60]
In addition, the present invention provides a manufacturing method for providing a button-type secondary battery having the above configuration as Example 2.
[61]
The manufacturing method according to the present invention comprises the steps of preparing (providing) a first can 10 in which a first side surface 12 is vertically formed along a perimeter of the first base surface 11 and the first base surface 11) A second can 20 having a second base surface 21 having a larger diameter and having a second side surface 22 vertically formed along the circumference of the second base surface 21 is provided (provided It starts from step 1).
[62]
Since the first can 10 and the second can 20 may be provided by a conventionally known molding method, a detailed description is omitted herein. In addition, the provided second can 20 has a perforated vent hole 23 in a predetermined size and number on the second side surface 22. The perforation of the vent hole 23 may be performed by a known method such as punching or drilling, depending on the material of the second can 20.
[63]
In a state in which the first side surface 12 faces upward, the electrode assembly is seated in the first can 10, and after the electrolyte is additionally mounted, the second side surface 22 is placed downward. The second can 20 covers the first can 10. At this time, before the second can 20 covers the first can 10, the gasket 30 is coupled to the first can 10 so as to be fixed to the outer circumferential surface of the first side surface 12. The gasket 30 may be bonded to the first can 10 before or after the electrode assembly is mounted, and may be attached to the first side surface 12 through an adhesive or the like, or by a method such as thermal fusion. Can be attached.
[64]
Therefore, when the first can 10 and the second can 20 are combined, the gasket 30 is positioned between the first side surface 12 and the second side surface 22 and the gasket 30 is a vent hole. It faces (23) (when viewed from the outside of the vent hole, the gasket is exposed to the outside through the vent hole).
[65]
In addition, the gasket 30 is deformed to fix the first can 10 and the second can 20. In an embodiment of the present invention, Figure 3a. As shown in 3b, in a state where the first can 10 and the second can 20 are placed on the flat surface plate 50, pressure is applied to the top, bottom, left, and right so that the movement is fixed (or inserted into a fixed position). When the vacuum hose (40) is connected to the vent hole (23) of the second can (20), the negative pressure inside the first can (10) and the second can (20) (negative pressure) is formed and deformation occurs.
[66]
At this time, since the inner space of the first can 10 and the second can 20 is filled with an electrode assembly and an electrolyte, it is supported even when a negative pressure is applied, whereas between the first side surface 12 and the second side surface 22 The space of is the point where the sound pressure acts, and deformation occurs because the bearing power is relatively weak. When deformation occurs due to negative pressure, a part of the first side surface 12 may be deformed together with the gasket 30, as shown in FIG. 3A, or the first side surface 12 as shown in FIG. 3B. ), only the gasket 30 may be deformed.
[67]
This difference is determined according to the size of the applied sound pressure and the area where the sound pressure acts, as well as the adhesion between the gasket 30 and the first side surface 12, the material of the first can 10, and the like. So it could be designed differently. In addition, when a part of the first side surface 12 is deformed as shown in FIG. 3A, a groove or the like may be formed locally in the first side surface 12 to increase (plastic or elastic) deformation. Specifically, the groove may be formed locally in a portion where bending or bending occurs in the first side surface 12. In addition, the gasket 30 may be configured to adhere to the first side surface 12 with a greater adhesive force at a portion where the pressure is concentrated and the gasket 30 is deformed. On the other hand, when the first side surface 12 is not deformed and only the gasket 30 is deformed as shown in FIG. 3B, the first side surface 12 and the gasket 30 are formed at a specific portion where the gasket 30 is deformed. It would be desirable to set the adhesive strength of the other lower than that of the others.
[68]
As shown in Figure 4a, the passage through which air moves between the first side surface 12 and the second side surface 22 is formed narrower than the other places inside the first can 10 and the second can 20, If the applied sound pressure is small or the space between the first side surface 12 and the second side surface 22 is large, sufficient deformation may not occur. Therefore, the distance between the first side surface 12 and the second side surface 22 must be sufficiently close so that sufficient deformation can be made so that the gasket 30 can be inserted into the vent hole 10 and fixed, and the applied sound pressure is sufficiently It will have to be big. In other words, when the fluid flowing through a wider cross section flows through a narrower cross section, the flow velocity of the fluid increases but the internal pressure decreases. The pressure between the second side surfaces 22 is relatively lower than in other places, but the first can 10 and the second can 20 are in a fixed state, so the gasket 30 is inserted into the vent hole 23. The pressure is applied in the direction (the direction in which the first side and the second side are in close contact with each other) to cause deformation. For reference, if there are a plurality of vent holes 23, when negative pressure is applied, the vent holes 23 are closed (through a separate mechanism) so that pressure leakage does not occur when negative pressure is applied. It would be desirable to apply negative pressure to the.
[69]
In addition, when the distance between the first side surface 12 and the second side surface 22 is formed to be larger due to a problem in the manufacturing process or other reasons, as shown in FIG. 4B, (between the first side surface and the second side surface) A portion of the gasket 30 may be configured to have a shape protruding toward the vent hole 23 so that the effect of concentrating the sound pressure may be caused by narrowing the distance. That is, the gasket 30 may be manufactured so that the thickness of a portion of the gasket 30 becomes thicker depending on the distance between the first side surface 12 and the second side surface 22 or according to the size of the sound pressure or the size of the vent hole 23. have.
[70]
In conclusion, in the manufacturing method according to the embodiment of the present invention, the movement of the first can 10 and the second can 20 is blocked before the negative pressure is applied (temporarily before being fixed by the gasket). However, according to the size of the first can 10 and the second can 20 or the strength of the sound pressure, the material of the first can 10, the adhesion between the first can 10 and the gasket 30, the gasket ( The thickness of 30) can be designed differently.
[71]
And, the (elastic or plastic) deformed gasket 30 does not need to protrude from the vent hole 23 (to maintain a smooth outer surface), but must remain in a pinched state. In addition, even if a certain part is protruded, the protruding part may be cut to maintain the smooth outer surface, and in the protruding state (so that the deformed part of the gasket is firmly fixed to the second can) to increase the fixing force It may be additionally applied.
[72]
Meanwhile, as described above, in the perforating step, a plurality of vent holes 23 may be perforated along the circumference of the side surface 22 of the second can 20. That is, as shown in Figure 5, it is configured to be paired in a direction facing each other (see i, ii, iii), or configured to be biased to one side to increase the fastening force in a specific direction (see iv, v). It might be possible.
[73]
[74]
In the present invention having the configuration as described above, since the fastening point of the first can 10 and the second can 20 is moved from the top of the battery to the side, it is possible to increase the height of the internal space relative to the total height. A larger capacity electrode assembly can be mounted, and the gasket 30 is deformed to fit into the vent hole 23 so that the first can 10 and the second can 20 are fixed. ) And the outer surface of the second can 20 can be configured smoothly.
[75]
In addition, the deformation of the gasket 30 is a difference between the pressure inside the space formed by the first can 10 and the second can 20 and the pressure outside the first can 10 and the second can 20 Since it is made in a size corresponding to the physical pressure causing stress and/or unnecessary deformation is not applied to the first can 10 and the second can 20, at least two vent holes 23 are formed. Therefore, it is possible to adjust the fastening force according to the required specifications.
[76]
In addition, some regions of the gasket 30 to be deformed are attached with lower adhesion than other regions, or negative pressure is applied in the unattached state so that deformation of the side surface 12 of the first can 10 does not occur. I can. In addition, a partial region of the gasket 30 to be deformed may be formed to have a thicker thickness than other regions, so that deformation can be made more easily.
[77]
In the above, although the present invention has been described by limited embodiments and drawings, the present invention is not limited thereto, and the technical idea of ​​the present invention and the following description by those of ordinary skill in the art to which the present invention pertains. Various implementations are possible within the equal range of the claims to be made.
Claims
[Claim 1]
A first can having a first side surface vertically formed along the circumference of the first base surface; It has a second base surface having a larger diameter than the first base surface of the first can, and a second side surface is vertically formed along the circumference of the second base surface, and a vent hole is perforated on the second side surface. A second can; And a gasket positioned between the first side surface and the second side surface when the first can and the second can are combined, wherein the first can and the second can have a first side surface inside the second side surface. A secondary battery, characterized in that the first can and the second can are fixed by being coupled to enter into and deformed so that the gasket is fitted into the vent hole.
[Claim 2]
The method of claim 1, wherein a first side surface of the first can faces upward from a first base surface, a second side surface of the second can faces downward from a second base surface, and the second can A secondary battery, characterized in that coupled to cover the top of the can.
[Claim 3]
The method of claim 1, wherein the gasket is deformed to a size corresponding to a pressure difference between the pressure inside the space formed by the first can and the second can and outside the first and second can Secondary battery.
[Claim 4]
The secondary battery according to any one of claims 1 to 3, wherein at least two vent holes are formed along a circumference of a side surface of the second can.
[Claim 5]
The secondary battery according to claim 4, wherein the second can has a disk shape on a plane, and an even number of vent holes are formed, and each of the vent holes is arranged to have a symmetrical pair with respect to the center of the disk.
[Claim 6]
The secondary battery according to claim 4, wherein the second can has a disk shape on a plane, and the vent holes are arranged to be denser in a specific region than in other regions based on the circumference of the disk shape.
[Claim 7]
A first can having a first side surface vertically formed along the circumference of the first base surface and a second base surface having a larger diameter than the first base surface, and a second side surface vertically along the circumference of the second base surface. A method of manufacturing a secondary battery in which a second can formed of is combined, comprising: providing the first can; Providing the second can; A perforating step of perforating a vent hole on a side surface of the second can; A coupling step of coupling the first can and the second can so that the gasket is positioned between the first side surface of the first can and the second side surface of the second can, and the gasket faces the vent hole; And a fixing step of fixing the first can and the second can by deforming the gasket so that the gasket fits into the vent hole.
[Claim 8]
The method of claim 7, wherein in the fixing step, the gasket is deformed to fit into the vent hole when negative pressure is applied to the vent hole from the outside.
[Claim 9]
The method of claim 8, further comprising a temporary fixing step of fixing the movement of the first can and the second can before applying negative pressure to the vent hole.
[Claim 10]
The method of claim 8, wherein negative pressure is applied while the gasket is attached to the surface of the side surface of the first can.
[Claim 11]
11. The method of claim 10, wherein a portion of the gasket to be deformed is attached with a lower adhesive force than other regions, or a negative pressure is applied in a state where it is not attached.
[Claim 12]
11. The method of claim 10, wherein a partial region of the gasket to be deformed has a different thickness from that of another region.
[Claim 13]
13. The method according to any one of claims 7 to 12, wherein in the perforating step, at least two vent holes are formed along a circumference of a side surface of the second can.