Title of invention: secondary battery
Technical field
[One]
This application claims the benefit of priority based on Korean Patent Application No. 10-2018-0143697 filed on November 20, 2018, and all contents disclosed in the documents of the Korean patent application are included as part of this specification.
[2]
The present invention relates to a cylindrical secondary battery, and more particularly, to a secondary battery having an improved cooling performance by providing a cooling member.
[3]
Background
[4]
Secondary batteries, which are widely used in various digital devices and transportation means such as vehicles, have the feature of being capable of repetitive charging and discharging. In addition, research and development to increase efficiency and improve safety are continuously being conducted.
[5]
Secondary batteries can be classified in various ways according to the shape of the battery case or the material of the electrode assembly, but when classified according to the shape of the battery case, cylindrical, rectangular, and pouch types are most widely manufactured.
[6]
Among them, in the cylindrical secondary battery, the electrode assembly 30 is embedded in the cylindrical can 10 having an open upper side and a hollow, and the top cap 20 is coupled to the upper end of the can 10. Referring to FIG. 1, which is a longitudinal sectional view showing the internal shape of a conventional cylindrical secondary battery, the can 10 is connected through an electrode assembly 30 and a negative electrode tab 60 at the bottom, and the top cap 20 is a positive electrode. It is connected to the electrode assembly 30 through the tab 40. In addition, the positive electrode tab 40 and the negative electrode tab 60 are equipped with an insulator or insulated so as to be electrically insulated from each other.
[7]
In addition, a general cylindrical secondary battery has a safety vent that breaks to discharge gas when the internal gas pressure increases to suppress the occurrence of explosion and ignition, a PTC element that blocks current at high temperatures, and blocks the current when the internal pressure of the battery increases. A current interrupt device (CID) or the like is additionally mounted on the top cap.
[8]
Meanwhile, a secondary battery mounted in a device requiring high rotation of a motor, such as a quick board, an electric drill, and a wireless vacuum cleaner, is designed to allow a high current to flow. However, as the high current flows, heat is inevitably generated in the electrode assembly 30.
[9]
For example, when the battery is discharged with a current of 10A or more at room temperature, the temperature of the electrode assembly 30 increases by 40℃ or more by the resistance, and the resistance increases as the temperature rises, making it difficult to maintain high current discharge. Could.
[10]
Accordingly, research and development has been made to lower the basic resistance of the electrode assembly, but there is a limit to only lowering the resistance of electrodes and components.
[11]
Detailed description of the invention
Technical challenge
[12]
Accordingly, an object of the present invention is to provide a secondary battery capable of rapidly and efficiently cooling heat generated during high current discharge so as to solve the above-described problems.
[13]
Means of solving the task
[14]
In the present invention for achieving the above object, the electrode assembly is mounted inside a cylindrical can, a top cap connected to the positive electrode of the electrode assembly is coupled to the upper end of the can, and the can is connected to the negative electrode. And a cooling member that receives and discharges heat generated from the electrode assembly and the can, and is coupled to a lower portion of the can, wherein the cooling member includes a plurality of cooling fins arranged parallel to each other.
[15]
Further, in Embodiment 1 of the present invention, the cooling fins are disposed in a direction parallel to the longitudinal direction of the can, and the bottom surface of the can is formed in a plane perpendicular to the longitudinal direction of the can.
[16]
In the second embodiment of the present invention, the bottom surface of the can has a shape in which the height gradually increases from the rim to the center.
[17]
At this time, the electrode assembly has a concave shape in which a portion contacting the bottom surface of the can corresponds to the shape of the bottom surface of the can, and is embedded in the can to fill the recessed space formed by the shape of the bottom surface of the can. .
[18]
The cooling fins formed on the cooling member correspond to the shape of the bottom surface of the can, and those disposed on the rim of the bottom surface of the can have a relatively short length, and become gradually longer as they get closer to the center of the bottom surface of the can.
[19]
The electrode assembly has a through hole perforated at a center along the longitudinal direction of the can, and the cooling member includes a center rod inserted into the through hole.
[20]
The cathode of the electrode assembly is electrically connected to the center rod, and the center rod is electrically connected to the can. At this time, the cathode of the electrode assembly is electrically connected at the upper end of the center rod.
[21]
In the third embodiment of the present invention, one of the cooling fins has a larger diameter than the other cooling fins. In this case, it is preferable that the cooling fins having a larger diameter are formed at positions corresponding to the center of the can bottom surface.
[22]
Since this fin (a cooling fin having a larger diameter than other cooling fins) has a length that protrudes further downward than other cooling fins, it can be used as a negative terminal.
[23]
In addition, in the present invention, the cooling member is preferably made of a material having the same or greater thermal conductivity as the can.
[24]
Effects of the Invention
[25]
In the present invention having the above configuration, since the cooling member having a plurality of cooling fins is coupled to the lower portion of the can, it has the effect of discharging heat generated from the electrode assembly more quickly.
[26]
Since the bottom surface of the can has a shape that gradually increases in height from the rim to the center, it is possible to prevent shape deformation when swelling occurs due to heat generation (can prevent deformation of the can due to internal pressure. In addition, since the electrode assembly has a shape that fills the recessed space formed by the shape of the bottom of the can, corresponding to the shape of the bottom of the can, it is possible to increase the capacity.
[27]
In addition, the electrode assembly has a through hole perforated in the center along the longitudinal direction of the can, and the cooling member includes a center rod inserted into the through hole, so that heat generated inside the electrode assembly is more efficiently discharged to the outside. I can make it.
[28]
The negative electrode tab of the electrode assembly is electrically connected to the center rod, and the center rod is electrically connected to the can. In addition, one of the cooling fins has a larger diameter than other cooling fins. At this time, since the cooling fins having a larger diameter are formed at a position corresponding to the center of the bottom surface of the can, the cooling fins can be used as a negative terminal.
[29]
Brief description of the drawing
[30]
1 is a longitudinal cross-sectional view showing the interior of a conventional cylindrical secondary battery.
[31]
Figure 2 is a longitudinal cross-sectional view showing the interior of the secondary battery according to the first embodiment of the present invention.
[32]
Figure 3 is a perspective view showing a state in which the cooling member is separated from the secondary battery according to the first embodiment of the present invention.
[33]
4 and 5 are longitudinal sectional views showing the internal appearance of the secondary battery according to the second embodiment of the present invention.
[34]
6 is a perspective view showing a state in which the cooling member is separated from the secondary battery according to the second embodiment of the present invention.
[35]
7 is a perspective view showing a state in which the cooling member is separated from the secondary battery according to the third embodiment of the present invention.
[36]
Mode for carrying out the invention
[37]
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.
[38]
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.
[39]
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.
[40]
In the present invention, the electrode assembly 30 is mounted inside the cylindrical can 10, and the top cap 20 connected to the positive electrode tab 40 of the electrode assembly 30 is coupled to the upper end of the can 10, and the can ( 20) relates to a cylindrical secondary battery connected to the negative electrode tab 60, characterized in that the cooling member 50 is mounted on the lower portion of the can 10 (opposite the top cap), and hereinafter, the accompanying drawings are described. Embodiments according to the present invention will be described in more detail with reference to the present invention.
[41]
[42]
Example 1
[43]
[44]
FIG. 2 is a longitudinal sectional view showing an internal view of a secondary battery according to Example 1 of the present invention, and FIG. 3 is a perspective view showing a state in which a cooling member is separated from the secondary battery according to Example 1 of the present invention.
[45]
Referring to the drawings, in the present invention, an electrode assembly 30 and a cooling member 50 that receives and discharges heat generated from the can 10 are mounted under the can 10.
[46]
The cooling member 50 has a disk shape having a diameter sufficient to be mounted on the bottom surface 11 of the can 10, but the surface opposite to the surface attached to the bottom surface 11 of the can 10 A plurality of cooling fins 51 arranged parallel to each other has a protruding structure. In this case, the cooling member 50 is preferably made of a material having the same or greater thermal conductivity as the can 10.
[47]
The cooling fins 51 function to increase the surface area of ​​the cooling member 50 to increase the area in contact with the air, thereby increasing heat dissipation.
[48]
As shown, in this embodiment, the cooling fins 51 are arranged in a direction parallel to the longitudinal direction (up and down direction in FIG. 1) of the can 10 (up and down direction), and The bottom surface 11 is formed in a plane perpendicular to the longitudinal direction of the can 10.
[49]
[50]
Example 2
[51]
[52]
4 and 5 are longitudinal cross-sectional views showing the internal appearance of the secondary battery according to the second embodiment of the present invention, FIG. 4 is a view when the electrode assembly 30 has a flat bottom surface, and FIG. 5 is an electrode assembly 30 ) Is shown when it has a shape that fills the recessed space corresponding to the shape of the bottom surface 11 of the can 10. And, Figure 6 is a perspective view showing a state in which the cooling member is separated from the secondary battery according to the second embodiment of the present invention.
[53]
In this embodiment, the bottom surface 11 of the can 10 has a shape in which the height gradually rises from the edge portion toward the center, that is, has a shape that is concave upward.
[54]
In this way, the shape of the bottom surface 11 concavely increases robustness so as to suppress deformation of the can 10 due to an increase in internal pressure. In other words, the structure that has a concave shape like the bottom of a beverage can containing carbonated drinks (when the pressure increases due to the vaporization of the electrolyte inside by heat) is structurally stable to minimize deformation of the can 10. Provides.
[55]
In addition, the space formed by the shape of the bottom surface 11 of the can 10 may be configured such that the lower portion of the electrode assembly 30 is expanded and filled as shown in FIG. 5. That is, in this embodiment, the electrode assembly 30 may be formed in a conventional shape having a flat bottom surface as shown in FIG. 4, but as shown in FIG. 5, the bottom surface 11 of the can 10 In accordance with the shape, a portion that comes into contact with the bottom surface 11 of the can 10 may have a concave shape.
[56]
At this time, when the electrode assembly 30 fills the concave space formed by the shape of the bottom surface 11 of the can 10, as well as the effect of increasing the capacity of the electrode assembly 30, the electrode assembly 30 and the can 10 The contact area of) is also increased, so that heat conduction can be achieved more easily. Particularly, since the portion of the electrode assembly 30 that fills the recessed space comes into indirect contact with the cooling member 50 (with the bottom surface of the can sandwiched between), heat generated therein can be released more quickly.
[57]
And, in this embodiment, the cooling fin 51 formed on the cooling member 50 so that the bottom of the secondary battery (that is, the bottom of the can) is maintained in a flat state as shown in FIG. Arranged on the edge of the bottom surface 11 of the can 10 corresponding to the shape of the surface 11 is relatively short and the length gradually increases as it approaches the center of the bottom surface 11 of the can 10 It is formed long.
[58]
In addition, the electrode assembly 30 has a through hole (a part where the center rod is inserted in FIGS. 4 and 5) at the center along the longitudinal direction of the can 10, and the cooling member 50 is inserted into the through hole. It has a center rod (52).
[59]
The center rod 52 enters the hole 12 drilled in the bottom surface 11 of the can 10 and is inserted into the through hole, and enters to a height where no interference with the positive electrode tab 40 occurs. Since the center rod 52 is located at the center of the electrode assembly 30, heat generated from the electrode assembly 30 can be more quickly conducted to the lower cooling member 50.
[60]
In this embodiment, since the bottom surface 11 of the can 10 is not flat, it is difficult to weld the cathode tab 60 and the bottom surface of the can 10, so that the cathode tab 60 is a center rod 52 ) And are welded.
[61]
[62]
Example 3
[63]
[64]
7 is a perspective view showing a state in which the cooling member is separated from the secondary battery according to the third embodiment of the present invention.
[65]
The secondary battery according to the third embodiment of the present invention has the same structure as the structure of the second embodiment, but one of the cooling fins 51 has a larger diameter than the other cooling fins.
[66]
At this time, the cooling fins 51a having a larger diameter are fins formed at a position corresponding to the center of the bottom surface 11 of the can 10. Since the fin 51a has a length protruding further downward than the other cooling fins 51, it can be used as a negative terminal (electrically connected to an external device).
[67]
[68]
In the present invention having the above configuration, since the cooling member 50 having a plurality of cooling fins 51 is coupled to the lower portion of the can 10, the heat generated from the electrode assembly 30 can be discharged more quickly Has an effect.
[69]
Since the bottom surface 11 of the can 10 has a shape that gradually increases in height from the edge portion to the center, structural robustness is increased, and shape deformation can be prevented when swelling due to heat generation occurs.
[70]
In addition, since the electrode assembly 30 has a shape corresponding to the shape of the bottom surface 11 of the can 10 to fill the recessed space formed by the shape of the bottom surface of the can, the capacity can be increased. In addition, as the contact area between the electrode assembly and the can increases, the conductivity increases, so that the cooling performance may be improved.
[71]
In addition, since the electrode assembly 30 has a through hole perforated in the center along the longitudinal direction of the can 10, and the cooling member 50 includes a center rod 52 inserted into the through hole, the electrode assembly (30) It can dissipate the heat generated inside more efficiently to the outside.
[72]
The negative electrode tab 60 of the electrode assembly 30 is electrically connected to the center rod 52 so that the center rod 52 is electrically connected to the can 10. In addition, one of the cooling fins 51 (51a) has a larger diameter than other cooling fins. At this time, since the cooling fins 51a having a larger diameter are formed at a position corresponding to the center of the bottom of the can, the cooling fins may be used as a negative terminal. In addition, since the cooling fin 51a to be used as the cathode terminal has a further increased diameter, resistance is reduced and heat dissipation can be made more easily.
[73]
In addition, when the diameter of the cooling fins 51a is increased, an area in which an external terminal can be contacted increases, and accordingly, it may be remarkably easy to connect the terminals of the charging/discharging device during charging and discharging of the secondary battery.
[74]
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]
An electrode assembly is mounted inside a cylindrical can, and a top cap connected to the positive electrode of the electrode assembly is coupled to the top of the can, and the can is a secondary battery connected to the negative electrode, receiving heat generated from the electrode assembly and discharging it. And a cooling member coupled to a lower portion of the can, wherein the cooling member includes a plurality of cooling fins arranged parallel to each other.
[Claim 2]
The secondary battery according to claim 1, wherein the cooling fins are arranged in a direction parallel to the length direction of the can.
[Claim 3]
The secondary battery according to claim 2, wherein the bottom surface of the can is formed in a plane perpendicular to the length direction of the can.
[Claim 4]
The secondary battery according to claim 2, wherein the bottom surface of the can has a shape that gradually increases in height from an edge portion toward the center.
[Claim 5]
The method of claim 4, wherein the electrode assembly has a concave shape in which a portion contacting the bottom surface of the can corresponds to the shape of the bottom surface of the can, and the electrode assembly fills the recessed space formed by the shape of the bottom surface of the can. A secondary battery, characterized in that built into the can.
[Claim 6]
The method of claim 4, wherein the cooling fins formed on the cooling member correspond to the shape of the bottom surface of the can, and are disposed on the edge of the bottom surface of the can. Secondary battery, characterized in that formed longer.
[Claim 7]
The secondary battery according to claim 6, wherein the electrode assembly has a through hole perforated at a center along the length direction of the can, and the cooling member includes a center rod inserted into the through hole.
[Claim 8]
The secondary battery of claim 7, wherein the negative electrode of the electrode assembly is electrically connected to a center rod, and the center rod is electrically connected to a can.
[Claim 9]
The secondary battery according to claim 8, wherein the negative electrode of the electrode assembly is electrically connected at an upper end of the center rod.
[Claim 10]
The secondary battery of claim 9, wherein one of the cooling fins has a diameter larger than that of other cooling fins.
[Claim 11]
The secondary battery according to claim 10, wherein the cooling fins having a larger diameter than other cooling fins have a length that protrudes further downward than other cooling fins.
[Claim 12]
The secondary battery according to claim 10, wherein the cooling fins having a diameter larger than that of other cooling fins are formed at a position corresponding to the center of the bottom of the can.
[Claim 13]
The secondary battery according to any one of claims 1 to 12, wherein the cooling member is made of a material having the same or greater thermal conductivity as the can.