BATTERY PACK MANUFACTURING METHOD USING HOT-MELT FIXING STRUCTURE AND BATTERY PACK MANUFACTURED USING THE SAME

Abstract

Disclosed herein is a method of manufacturing a battery pack including a battery cell having an electrode assembly received in a battery case, made of a laminate sheet including a resin layer and a metal layer, together with an electrolytic solution.

Claims

1. A method of manufacturing a battery pack comprising a battery cell having an electrode assembly received in a battery case, made of a laminate sheet comprising a resin layer and a metal layer, together with an electrolytic solution, the method comprising: (a) electrically connecting electrode terminals of a battery cell to electrode terminal connection parts of a protection circuit board (PCB) having a protection circuit formed thereon; (b) coupling an upper case to an upper part of the PCB; (c) bending an upper sealed portion of the battery cell, at which the electrode terminals are located, and loading the PCB, to which the upper case has been coupled, on an upper end of the battery cell such that the PCB is parallel to an outer wall of an electrode assembly receiving part of the battery cell; (d) placing the upper case, the PCB, and the battery cell, which have been coupled to each other, in a mold, which is provided in regions thereof corresponding to a peripheral edge of the battery cell with two or more injection ports, through which a hot-melt resin is injected; (e) injecting a hot-melt resin through the injection ports to perform a hot-melt process, in which the hot-melt resin fills a space defined between the upper case, the PCB, and the battery cell and the mold; and (f) removing a resultant structure from the mold and wrapping the resultant structure with a label.

2. The method according to claim 1, wherein the battery cell is configured to have a plate-shaped rectangular structure.

3. The method according to claim 1, wherein the battery pack is a detachable type battery pack, which is easily inserted into and removed from a device.

4. The method according to claim 1, wherein step (b) comprises coupling the upper case to the upper part of the PCB such that an external input and output terminal formed on an upper surface of the PCB is exposed through an opening formed in the upper case.

5. The method according to claim 1, wherein step (e) comprises fixing the PCB to the upper part of the battery cell through the hot-melt process.

6. The method according to claim 1, wherein the mold comprises a lower mold and an upper mold, which are coupled to each other such that the hot-melt process is performed, and wherein a structure corresponding to external shapes of the upper case, the PCB, and the battery cell, which have been coupled to each other, is carved in at least one selected from between the lower mold and the upper mold.

7. The method according to claim 6, wherein the injection ports are formed in the lower mold.

8. The method according to claim 1, wherein the mold has eight or more injection ports.

9. The method according to claim 1, wherein two or more injection ports are formed in an upper part of the mold, at which the electrode terminals are located.

10. The method according to claim 1, wherein two or more injection ports are formed in a lower part of the mold.

11. The method according to claim 1, wherein one injection port is formed in a middle of each side part of the mold.

12. The method according to claim 1, wherein the injection ports are formed in all regions of the mold.

13. The method according to claim 1, wherein at least one of the injection ports is formed in peripheral corners of the mold.

14. The method according to claim 13, wherein the injection ports are formed in all peripheral corners of the mold.

15. The method according to claim 1, wherein a distance between the injection ports ranges from 10 mm to 15 mm.

16. The method according to claim 1, wherein the hot-melt resin is at least one selected from a group consisting of polyamide resins.

17. The method according to claim 1, wherein the hot-melt process is performed at a temperature of 180 to 200° C.

18. The method according to claim 1, wherein the hot-melt process is performed at a pressure of 1 bar to 3 bar.

19. A battery pack manufactured using the method according to claim 1.

20. A device comprising the battery pack according to claim 19 as a power source.

21. The device according to claim 20, wherein the device is selected from among a mobile phone, a portable computer, a smart phone, a smart pad, a tablet PC, and a netbook computer.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0042] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0043] FIG. 1 is a sectional view schematically showing the structure of a mold used in a conventional hot-melt process;

[0044] FIG. 2 is a schematic view showing a method of coupling an upper case, a battery cell, and a protection circuit board (PCB) according to an embodiment of the present invention;

[0045] FIG. 3 is a schematic view showing the structure of the upper case, the battery cell, and the PCB that are coupled using the method of FIG. 2;

[0046] FIG. 4 is a sectional view schematically showing a mold according to an embodiment of the present invention, in which the resultant structure of FIG. 3 is disposed;

[0047] FIG. 5 is a sectional view schematically showing a process of injecting a hot-melt resin into the mold of FIG. 4;

[0048] FIG. 6 is a sectional view schematically showing a process of removing the resultant structure of FIG. 5 from the mold and labeling the resultant structure of FIG. 5 after the process of FIG. 5 has been completed;

[0049] FIG. 7 is a perspective view showing a battery pack manufactured through the processes of FIGS. 2 to 6;

[0050] FIG. 8 is a sectional view schematically showing the structure of a lower mold of FIG. 4;

[0051] FIG. 9 is a photograph showing a battery pack manufactured according to Example 1; and

[0052] FIG. 10 is a photograph showing a battery pack manufactured according to Comparative Example 1.

BEST MODE

[0053] Now, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted, however, that the scope of the present invention is not limited by the illustrated embodiments.

[0054] FIG. 2 is a schematic view showing a method of coupling an upper case, a battery cell, and a protection circuit board (PCB) according to an embodiment of the present invention, FIG. 3 is a schematic view showing the structure of the upper case, the battery cell, and the PCB that are coupled using the method of FIG. 2, FIG. 4 is a sectional view schematically showing a mold according to an embodiment of the present invention, in which the resultant structure of FIG. 3 is disposed, FIG. 5 is a sectional view schematically showing a process of injecting a hot-melt resin into the mold of FIG. 4, FIG. 6 is a sectional view schematically showing a process of removing the resultant structure of FIG. 5 from the mold and labeling the resultant structure of FIG. 5 after the process of FIG. 5 has been completed, and FIG. 7 is a perspective view showing a battery pack manufactured through the processes of FIGS. 2 to 6.

[0055] A method of manufacturing a battery pack 200 according to the present invention will be described with reference to FIGS. 2 to 7.

[0056] Referring first to FIGS. 2 and 3, electrode terminals 320 of a battery cell 300 are electrically connected to electrode terminal connection portions 410 of a PCB 400 having a protection circuit formed thereon, and then an upper case 500 is coupled to the upper part of the PCB 400. At this time, the upper case 500 is coupled to the upper part of the PCB 400 such that an external input and output terminal formed on the upper surface of the PCB 400 is exposed through an opening 510 formed in the upper case 500.

[0057] Subsequently, an upper sealed portion 310 of the battery cell 300, at which the electrode terminals 320 are located, is bent, and the PCB 400, to which the upper case 500 has been coupled, is loaded on the upper end of the battery cell 300 such that the PCB 400 is parallel to the outer wall of an electrode assembly receiving part of the battery cell.

[0058] As shown in FIG. 4, the upper case 500, the PCB 400, and the battery cell 300, which have been connected to each other, as described above, are placed in a mold provided in regions thereof corresponding to a peripheral edge 330 of the battery cell 300 with two or more injection ports, through which a hot-melt resin is injected. The mold includes a lower mold 210 and an upper mold 220, which are coupled to each other such that a hot-melt process is performed. The injection ports 211 are formed in the lower mold 210. Although not shown, a structure corresponding to the external shapes of the upper case, the PCB, and the battery cell, which have been coupled to each other, is carved in at least one selected from between the lower mold 210 and the upper mold 220.

[0059] Subsequently, as shown in FIG. 5, a hot-melt resin is injected through the injection ports 211 to perform a hot-melt process, in which the hot-melt resin fills a space defined between the upper case 500, the PCB 400, and the battery cell 300 and the mold 210. The PCB 400 is fixed to the upper part of the battery cell 300 through the hot-melt process.

[0060] Finally, as shown in FIGS. 6 and 7, the above components are removed from the mold 210 and are wrapped with a label 600 to manufacture a battery pack 200.

[0061] That is, in the method of manufacturing the battery pack 200 according to the present invention, the upper case 500, the PCB 400, and the battery cell 300, which are coupled to each other, are placed between the lower mold 210 and the upper mold 220, the lower mold 210 and the upper mold 220 are coupled to each other, and a hot-melt resin is injected through the injection ports 211 formed in the lower mold 210 to form a peripheral edge at the battery cell 300, whereby the battery pack 200 is manufactured.

[0062] In the battery pack 200 manufactured as described above, various members, such as a PCM case necessary to load the PCB 400 on the battery cell 300, a frame necessary to mount the battery cell, and a lower case for sealing the lower end of the battery pack, are not required. Consequently, the number of parts required to manufacture the battery pack is greatly reduced, whereby it is possible to reduce manufacturing cost. In addition, the size of the battery cell is increased in proportion to the volume of the omitted parts, whereby it is possible to maximize the capacity of the battery cell.

[0063] In addition, the upper case 500, the PCB 400, and the battery cell 300 are coupled to each other only through a hot-melt process, whereby it is possible to improve manufacturing efficiency.

[0064] Meanwhile, the structure of the lower mold 210 will be described in more detail with reference to FIG. 8, which is a sectional view schematically showing the structure of the lower mold of FIG. 4.

[0065] Specifically, referring to FIG. 8 together with FIGS. 6 and 7, eight injection ports 211 are formed in the lower mold 210. Specifically, three injection ports 211 are formed in the upper part 210a of the lower mold 210, at which the electrode terminals are located, three injection ports 211 are formed in the lower part 210b of the lower mold 210, and one injection port 211 is formed in the middle of each side part 210c of the lower mold 210.

[0066] That is, the injection ports 211 are formed in all regions of the lower mold 210, whereby it is possible to thickly form a peripheral edge of the upper part of the battery cell, at which the PCB is located, in order to stably fix and mount the PCB to the battery cell without using a conventional PCM case, to seal the lower end of the battery cell 300 and form a peripheral edge 330, which is necessary to fix the battery cell 30, at the lower end of the battery cell 300 without using a lower case, and to form a peripheral edge 330, which is necessary to protect the battery cell 300 from external impact, at the side surface of the battery cell 300 without using conventional side frames, which are provided at the battery cell.

[0067] In addition, since the injection ports 211 are formed in all peripheral corners 212 of the lower mold, the hot-melt resin does not pass through bent parts of the mold when the hot-melt resin flows in the mold, whereby the mobility of the hot meld resin is improved.

[0068] The distances d and d′ between the injection ports 211 may range from 10 mm to 15 mm.

[0069] In the case in which the distances d and d′ between the injection ports 211 are less than 10 mm, the number of injection ports 211 formed in the lower mold 210 is excessively increased, whereby the manufacturing process is complicated and the manufacturing cost is increased. On the other hand, in the case in which the distances d and d′ between the injection ports 211 are greater than 15 mm, the movement distance of the hot-melt resin is increased, whereby it is difficult to achieve the desired effects of the present invention.

[0070] In conclusion, in the method of manufacturing the battery pack 200 according to the present invention, the distances between the injection ports 211 are reduced, and the injection ports 211 are effectively disposed along the lower mold 210, whereby it is possible to increase the mobility of the hot-melt resin and to form the peripheral edge 330 at a low pressure, compared to the conventional art.

[0071] Hereinafter, the present invention will be described in more detail with reference to the following example. This example is provided only for illustration of the present invention and should not be construed as limiting the scope of the present invention.

EXAMPLE 1

[0072] A battery cell, a PCM, and an upper case, which were coupled to each other, were placed in a mold having eight injection ports, and a hot-melt process was performed using Local 630 Resin (Austromelt), which was a polyamide resin, as a hot-melt resin at a temperature of 190° C. and a pressure of 2 bar. A molded product was removed from the mold and was then wrapped with a label to manufacture a battery pack.

[0073] The photograph of the manufactured battery pack is shown in FIG. 9.

COMPARATIVE EXAMPLE 1

[0074] A PCM including a PCM case was attached to the outer surface of a battery cell using a piece of double-sided adhesive tape, an upper case was coupled to the upper part of the PCM, and a lower case was coupled to the lower end of the battery cell.

[0075] The battery cell, the PCM, the PCM case, the double-sided adhesive tape, the upper case, and the lower case, which were coupled as described above, were placed in a mold having two injection ports, and a hot-melt process was performed using Bostic TH8671, which was a polyamide resin, as a hot-melt resin at a temperature of 190° C. and a pressure of 2 bar. A molded product was removed from the mold and was then wrapped with a label to manufacture a battery pack.

[0076] The photograph of the manufactured battery pack is shown in FIG. 10.

[0077] As can be seen from the photograph of the battery pack shown in FIG. 10, in the battery pack manufactured according to Comparative Example 1, the side parts of the battery pack were not filled with the hot-melt resin after injection, whereby unmolded portions were present in the battery pack. In addition, an overflow phenomenon, in which the hot-melt resin overflowed at the upper part of the battery pack, occurred, whereby deviation in the dimensions of the battery pack occurred.

[0078] In contrast, as can be seen from the photograph of the battery pack shown in FIG. 9, in the battery pack manufactured according to Example 1, the battery pack was completely filled with the hot-melt resin, and no overflow phenomenon occurred, whereby deviation in the dimensions of the battery pack did not occur.

[0079] As described above, in the method of manufacturing the battery pack according to the present invention, the upper case, the PCB, and the battery cell are simultaneously coupled to each other through the hot-melt process without using additional members, such as double-sided adhesive tape and a PCM case, whereby it is possible to improve manufacturing efficiency and reduce manufacturing cost due to the reduction in the number of parts. In addition, in the method of manufacturing the battery pack according to the present invention, two or more injection ports are formed in the mold in order to improve the mobility of the hot-melt resin in the mold, whereby it is possible to improve the efficiency with which the hot-melt resin is filled in the mold and to reduce the defect rate of molded products. Furthermore, the peripheral edge is formed at the battery cell at a low pressure, whereby it is possible to minimize the impact applied to the battery cell during the hot-melt process. Moreover, it is possible to improve the durability of the battery pack using the hot-melt fixing structure. Besides, side frames are not provided at the battery cell, whereby it is possible to increase the size of the battery cell in proportion thereto and thus to increase the capacity of the battery pack, compared to a conventional frame hot-melt type method of manufacturing the battery pack, in which both a frame and a hot-melt resin are used to mount the battery cell.

[0080] Although the exemplary embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

INDUSTRIAL APPLICABILITY

[0081] As is apparent from the above description, in a method of manufacturing a battery pack according to the present invention, an upper case, a PCB, and a battery cell are simultaneously coupled to each other through a hot-melt process without using additional members, such as double-sided adhesive tape and a PCM case, whereby it is possible to improve manufacturing efficiency and reduce manufacturing cost due to the reduction in the number of parts. In addition, in the method of manufacturing the battery pack according to the present invention, two or more injection ports are formed in a mold in order to improve the mobility of a hot-melt resin in the mold, whereby it is possible to improve the efficiency with which the hot-melt resin is filled in the mold and to reduce the defect rate of molded products. Furthermore, the peripheral edge is formed at the battery cell at a low pressure, whereby it is possible to minimize the impact applied to the battery cell during the hot-melt process. Moreover, it is possible to improve the durability of the battery pack using the hot-melt fixing structure. Besides, side frames are not provided at the battery cell, whereby it is possible to increase the size of the battery cell in proportion thereto and thus to increase the capacity of the battery pack, compared to a conventional frame hot-melt type method of manufacturing the battery pack, in which both a frame and a hot-melt resin are used to mount the battery cell.