WO2014003361A1

WO2014003361A1 - Easily assembled all-in-one secondary battery module

Info

Publication number: WO2014003361A1
Application number: PCT/KR2013/005463
Authority: WO
Inventors: Tae Il Kim; Kwan Yong Kim
Original assignee: SK Innovation Co Ltd
Current assignee: SK Innovation Co Ltd
Priority date: 2012-06-28
Filing date: 2013-06-20
Publication date: 2014-01-03
Anticipated expiration: 2014-12-28
Also published as: KR101908452B1; KR20140002118A

Abstract

Provided is an easily assembled all-in-one secondary battery module in which two battery cells stacked in parallel with each other are coupled to a cell frame and received in a case, a lower side thereof is coupled to a lower cap, a connection mold is inserted between facing electrode tabs of the two battery cells so that terminals are connected to the electrode tabs, and an upper cap is then coupled to an upper side of the connection mold, thereby being capable of coupling battery cells to each other to be easily configured as a module, improving a low mechanical strength of the battery cell, and easily achieving an electrical connection between the battery cells.

Description

EASILY ASSEMBLED ALL-IN-ONE SECONDARY BATTERY MODULE

The present invention relates to an easily assembled all-in-one secondary battery module capable of coupling battery cells to each other to be easily configured as a module, improving a low mechanical strength of the battery cell, and easily achieving an electrical connection between the battery cells.

In general, a secondary battery is capable of being charged and discharged to be applied to various fields such as a digital camera, a cellular phone, a notebook and a hybrid car, unlike a primary battery, and research thereof has been actively conducted. An example of the secondary battery may include a nickel-cadmium battery, a nickel-metal hydride battery, a nickel-hydrogen battery, and a lithium secondary battery. In addition, among the secondary batteries, research into a lithium secondary battery having high energy density and discharge voltage has been largely conducted and the lithium secondary battery has been commercialized to be widely used.

In addition, the lithium secondary battery is capable of being manufactured so as to have various shapes, and cylindrical type and prismatic type lithium secondary batteries have been usually exemplified as the lithium secondary battery. A lithium polymer battery recently in the spotlight is manufactured in a pouched type having flexibility, such that the shape thereof is relatively varied.

Since the pouch typed lithium polymer battery (hereinafter, referred to as a “pouch typed cell”) is easily bent or curved, a compact case is coupled to the outside thereof to reinforce a low strength of the pouch typed cell. In addition, due to a need for high output and large capacitance, a plurality of pouch typed cells are stacked to be configured as a battery module or a battery pack.

As described above, since the pouch typed cell does not have an excellent mechanical strength of a pouch which seals an electrode body, in order to manufacture the battery module having a safety structure, the pouch typed cells should be mounted on a pack case such as a cartridge, or the like, to manufacture the battery module and electrode tabs of the plurality of pouch typed cells should be electrically connected to each other in series or in parallel with each other, such that a size of the battery module is increased, and a structure thereof is complicated.

As a related art document association with the above-description, “Battery Module” which is US Patent No. 7794875 has been disclosed.

[Related Art Document]

[Patent Document]

US 7794875 B2 (September 14. 2010)

An object of the present invention is to provide an easily assembled all-in-one secondary battery module capable of minimizing an increase in weight and size thereof while reinforcing a low mechanical strength of a battery cell, easily achieving an electrical connection between the battery cells, and more firmly fixing the battery cells to a case to thereby improve safety.

In one general aspect, an easily assembled all-in-one secondary battery module includes: two battery cells having electrode tabs formed at one side thereof and stacked in parallel with each other; a cell frame interposed between the two battery cells and having an electrode body of the battery cells installed at an inner side thereof; a case having opened both sides to receive the battery cells therein, the battery cells being coupled to both sides of the cell frame; a lower cap coupled to the opened one side of the case and coupled to an opposite side to a side at which the electrode tabs are positioned; a connection mold inserted between facing electrode tabs of the two battery cells to thereby be coupled to the cell frame and having a plurality of terminals formed at one side thereof, the terminals being connected to the electrode tabs; and an upper cap coupled to the opened other side of the case to which the lower cap is coupled and having a cut-part formed therein so that the terminals of the connection mold are exposed to the outside.

The cell frame may include an upper frame, a pair of side frames, and a lower frame and have an open part formed at an inner side thereof, and the electrode body of the battery cells may be installed in the open part.

The pair of side frames may have catching grooves formed at both sides thereof, and pouches of both sides of the two battery cells may be bent in a direction in which the two battery cells face each other, the bent pouches of the battery cells being inserted into the catching grooves of the side frames, respectively.

The upper frame may have a hollow part formed at both sides each thereof and having an opened upper surface, each of both side surfaces of the hollow part may be provided with a coupling hole, and each of both sides of a lower surface of the connection mold may be provided with a hook inserted into the hollow part of the upper frame to thereby be coupled to the coupling hole.

The electrode tab of the battery cells may protrude upwardly of the upper frame, and the terminals of the connection mold may be bent from an upper surface thereof to one side surface or both side surfaces thereof.

The side frame may protrude outwardly of a lower portion of the pouch of the battery cells in a state in which the battery cells are coupled to the cell frame.

With the easily assembled all-in-one secondary battery module according to the present invention, the battery cells may be firmly fixed in the case by the cell frame to improve the safety, the battery cells may be fixed in the compact case to increase utilization of the space, and it is easy to electrically connect the electrode tabs of the battery cells to each other to thereby be easily assembled as the module.

FIGS. 1 and 2 are perspective views showing a battery cell and a cell frame according to an embodiment of the present invention;

FIG. 3 is a cross sectional view taken along a line aa’ of FIG. 2;

FIGS. 4 and 5 are an exploded perspective view and an assembly perspective view showing an easily assembled all-in-one secondary battery module according to an embodiment of the present invention, respectively;

FIGS. 6A and 6B and 7A and 7B are an exploded perspective view and an assembly perspective view showing a structure in which an upper frame and a connection mold are coupled to each other according to an embodiment of the present invention, respectively;

FIG. 8 is an exploded perspective showing a structure in which an upper cap and the connection mold are coupled to each other according to the embodiment of the present invention;

FIGS. 9A and 9B and 10A and 10B are cross-sectional views taken along lines AA’, BB’, CC’, and DD’ of FIG. 5, respectively;

FIGS. 11 and 12 are cross-sectional views showing a state in which a lower cap is coupled in the case according to the embodiment of the present invention.

[Detailed Description of Main Elements]

1000: secondary battery module

100: battery cell

100a: first battery cell 100b: second battery cell

110: electrode body 120: electrode tab

120a: cathode tab 120b: anode tab

130: pouch

200: cell frame 201: open part

210: upper frame

211: hollow part 212: coupling hole

220: side frame 221: catching groove

230: lower frame

300: case

400: lower cap 410: injection inlet

500: connection mold

510: terminal 511: cathode terminal

512: anode terminal 513: voltage sensing terminal

540: hook 541: guide

550: guide plate 560: insertion groove

561: through-hole

570: nut 571: bolt

600: upper cap

610: cut-part 620: fixing hole

630: protrusion 640: groove

Hereinafter, an easily assembled all-in-one secondary battery module according to an embodiment of the present invention as described above will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily practice the present invention.

FIGS. 4 and 5 are an exploded perspective view and an assembly perspective view showing an easily assembled all-in-one secondary battery module according to the embodiment of the present invention, respectively.

As shown in FIGS. 4 and 5, the easily assembled all-in-one secondary battery module 1000 according to the embodiment of the present invention may include: two battery cells 100 having electrode tabs 120 formed at one side thereof and stacked in parallel with each other; a cell frame 200 interposed between the two battery cells 100 and having an electrode body 110 of the battery cells 100 installed at an inner side thereof; a case 300 having opened both sides to receive the battery cells 100 therein, the battery cells being coupled to both sides of the cell frame 200; a lower cap 400 coupled to the opened one side of the case 300 and coupled to an opposite side to a side at which the electrode tabs 120 are positioned; a connection mold 500 inserted between facing electrode tabs 120 of the two battery cells 100 to thereby be coupled to the cell frame 200 and having a plurality of terminals 510 formed at one side thereof, the terminals 510 being connected to the electrode tabs 120; and an upper cap 600 coupled to the opened other side of the case 300 to which the lower cap 400 is coupled and having a cut-part 610 formed therein so that the terminals 510 of the connection mold 500 are exposed to the outside.

First, the battery cell 100 has the electrode tab 120 formed at one side of the electrode body 110 as shown in FIG. 1. The electrode body 110 is configured of a cathode, an anode, an electrolyte, and a separating plate that separates the cathode and the anode to be charged and discharged, and the electrode tab 120 transmit a current generated from the electrode body 110 at the time of discharging or a current introduced from the outside at the time of charging. In addition, the battery cell 100 may be a pouch typed cell sealed by being surrounded with pouch 130 or may have an external member coupled to an outer side of the pouch typed cell, and the electrode body 110 sealed by the pouch 130 may protrude to only one side surface of the pouch 130 or both side surfaces thereof, based on the pouch 130.

Further, as shown in FIG. 2, the two battery cells 100 are stacked in parallel with each other so that the electrode tabs 120 face each other, and in the case in which the electrode body 110 protrudes to the one side surface of the pouch 130, the battery cells 100 are stacked so that protruding sides of the electrode body 110 are in contact with each other, such that the pouch 130 of the two battery cells 100 is positioned at an outer portion in a width direction. That is, the battery cells 100 are stacked so that the electrode tabs 120 of the two battery cells 100 are spaced apart from each other by a predetermined distance without being in contact with each other.

In this case, as shown in FIGS. 1 and 2, the cell frame 200 is interposed between the two battery cells 100 to be closely adhered to the battery cells 100. Here, the cell frame 200 includes an upper frame 210, a pair of side frames 220, and a lower frame 230 and has an open part 201 formed at an inner side thereof due to those

frames

210, 220, and 230, and the electrode body 110 of the battery cells 100 is installed in the open part 201. That is, the electrode body of the battery cells 100 may be installed at the open part 201 of the cell frame 200, and an edge portion of the pouch 130 of the battery cells 100 may be closely adhered to the cell frame 200.

In addition, the two battery cells 100 are coupled to both sides of the cell frame 200, and an insulation tape, or the like, may be used to cover the outer side thereof, such that the two battery cells may be fixed to both sides of the cell frame 200.

The two battery cells 100 and the cell frame 200 coupled to each other as described above are inserted into the case 300 to be received therein as shown in FIGS. 4 and 5, and the case 300 may have both sides opened thereof. Here, the case 300 may be made of a metal plate having a thin thickness of 0.1mm to 1.0mm, a central portion on both surfaces in a width direction may be recessed to an inner side of the case 300, or a plurality of grooves recessed to the inner side may be formed to allow the two battery cells 100 received in the case 300 to be closely adhered to the cell frame 200.

The lower cap 400 may have a hollow inner portion thereof and an upper side opened thereof, and may be coupled to the opened portion of the case 300 at an opposite side to a side at which the electrode tabs 120 of the battery cells 100 are positioned in a state in which the two battery cells 100 are inserted in the case 300. That is, the lower cap 400 is formed in a cap type, and the opened lower side of the case 300 is inserted into a hollow inner side of the lower cap 400 and fixed thereto, such that the lower side of the case 300 is closed.

Here, when the battery cells 100 are coupled to the lower cap 400 while being received in the case 300, the case in which the electrode tabs 120 protrude to the outside of the upper side of the case 300 is easier to achieve an electrical connection in the electrode tabs 120 by a welding process, such that it is preferable that the case 300 may be slightly shorter than the battery cell 100.

The connection mold 500 having the plurality of terminals 510 formed therein may be inserted between the facing electrode tabs 120 of the two battery cells 100 and the inserted terminals 510 may be electrically connected to the electrode tabs 120 by the welding process. That is, since the connection mold 500 is inserted between the facing electrode tabs 120 of the two battery cells 100 and coupled to the cell frame 200 to support the inner side thereof, the electrode tabs 120 are pressed in a width direction of the connection mold 500 from the side surface thereof to thereby be easily welded to the terminals 510, and the terminals 510 connected to the electrode tab 120 are fixed to the connection mold 500.

In addition, the upper cap 600 is coupled to the upper side of the inserted connection mold so as to cover the connection mold 500 and the electrode tabs 120, the inner portion is hollow, and the lower side is opened, thereby being insertedly coupled to the outer side of the case 300. Here, the cut-part 610 may be formed so that the terminals 510 of the connection mold 500 are exposed to the outside, such that when the upper cap 600 is coupled to the connection mold 500, the terminals 510 may be connected to external circuits.

With the easily assembled all-in-one secondary battery module according to the present invention, the battery cells are fixed to the cell frame and then firmly fixed to an inside of the case to thereby improve safety, and the battery cells is fixed in the compact case to increase utilization of the space, and it is easy to electrically connect the electrode tabs of the battery cells to each other to thereby be easily assembled as the module.

In addition, the electrode body of the battery cell is installed and fixed to the inner side of the cell frame, thereby preventing an edge portion of the pouch having a weak strength in the battery cell from being deformed and damaged. In addition, since the electrode body is installed at the inner side of the cell frame, the dimensional tolerance of the electrode body of the battery cell may be allowed by the cell frame, such that an assembly with the case, the connection mold, or the like, may be easily achieved.

In addition, the two battery cells 100 may be stacked so that a cathode tab 120a and an anode tab 120b face each other, and the terminal 510 may be configured of a cathode terminal 511, an anode terminal 512, and a voltage sensing terminal 513. In addition, as shown in FIGS. 9 and 10, the cathode terminal 511 may be bent from the upper surface of the connection mold 500 to one side surface thereof, the anode terminal 512 may be bent from the upper surface to the other side surface of the connection mold 500, and the voltage sensing terminal 513 may be bent from the upper surface to both side surfaces of the connection mold 500. Here, the cathode terminal 511 may be connected to the cathode tab 120a of a first battery cell 100a, the anode terminal 512 may be connected to the anode tab 120b of a secondary battery cell 100b, and the voltage sensing terminal 513 may be connected to the anode tab 120b of the first battery cell 100a and the cathode tab 120a of the secondary battery cell 100b, such that the two battery cells 100 may be connected in series. Therefore, the anode terminal 511 and the cathode terminal 512 may become output terminals connected to the external circuits, and the voltage sensing terminal 513 may be connected to the cathode terminal 511 and the anode terminal 512 through a separate protecting circuit, respectively, to measure each voltage of the

battery cells

100a and 100b.

Further, in order to connect two battery cells 100 to each other in parallel, the battery cells are stacked so that electrode tabs 120 having the same polarities of the battery cells 100 face each other, such that the cathode tabs 120a of the first battery cell 100a and the second battery cell 100b may be connected to the cathode terminal 511, and the anode tabs 120b may be connected to the anode terminal 512. Here, since the two battery cells 100 are stacked so that the electrode tabs 120 having the same polarities face each other, it is preferable that the cathode terminal 511 is formed at one side of the connection mold 500 in the length direction, and the anode terminal 512 is formed at the other side thereof in the length direction. Therefore, the two battery cells 100 are connected to each other in parallel, such that the cathode terminal 511 and the anode terminal 512 may serve as the external terminal connected to the external circuit, and at the same time, may serve as the voltage sensing terminal connected through the separate protecting circuit.

In addition, the pair of side frames 220 may have catching grooves 221 formed at both sides thereof, and the pouches of both sides of the two battery cells may be bent in a direction in which the two battery cells face each other, the bent pouches of the battery cells being inserted into the catching grooves of the side frames, respectively.

That is, as shown in FIGS. 1 to 3, the edge portions of the pouch 130 formed at both sides of the battery cells 100 in the length direction are bent in a direction in which the two battery cells 100 face each other, the side frame 220 has the catching groove 221 formed at both sides thereof in the width direction to have an H shaped cross section, the edge portion of the pouch 130 at both sides of the two battery cells 100 is inserted into the catching groove 221 of the side frame 220, and the electrode body 110 is installed between the pair of side frames 220.

Therefore, the battery cells 100 may be more firmly fixed to the cell frame 200.

In addition, as shown in FIGS. 6 and 7, the upper frame 210 may have a hollow part 211 formed at both sides each thereof and having an opened upper surface, each of both side surfaces of the hollow part 211 may be provided with a coupling hole 212, and each of both sides of a lower surface of the connection mold 500 may be provided with a hook 540 inserted into the hollow part 211 of the upper frame 210 to thereby be coupled to the coupling hole 212.

According to the easily assembled all-in-one secondary battery module having the above-described configuration, the upper frame 210 may be easily coupled to the connection mold 500, and the connection mold 500 may be inserted between the facing electrode tabs 120 of the battery cells 100 and press-fitted to the upper frame 210.

In addition, the electrode tab 120 of the battery cells 100 may protrude upwardly of the upper frame 210, and the terminals 510 of the connection mold 500 may be bent from an upper surface to one side surface or both side surfaces thereof. Therefore, when the connection mold 500 is insertedly coupled between the facing electrode tabs 120 of the battery cells 100, the bent side surfaces of the terminals 510 and the electrode tab 120 of the battery cells 100 may be overlapped with each other, such that it is easy to connect the electrode tab 120 and the terminal 510 to each other by a welding process at both sides in the width direction.

Further, the side frame 220 may protrude outwardly of a lower portion of the pouch 130 of the battery cells 100 in a state in which the battery cells 100 are coupled to the cell frame 200. That is, in the case in which the lower side of the side frame 220 is longer than the lower portion of the pouch 130 of the battery cells 100 as shown in FIGS. 11 and 12, the pouch 130 may not be in contact with the lower cap 400 in a state in which the electrode body 110 of the battery cell 100 is caught by the lower frame 230. Accordingly, the lower portion of the pouch 130 of the battery cells 100 may be prevented from being deformed and damaged.

In addition, the connection mold 500 may have a pair of guide plates 550 at the center of both side surfaces thereof in the width direction, such that the upper frame 210 and the pouch 130 of the two battery cells 100 may be inserted between the guide plates 550. That is, as shown in FIG. 9B, when the connection mold 500 is inserted between the electrode tabs 120 facing each other of the battery cells 100, since a portion of the pouch 130 of the battery cells 100 is inserted to the inner side of the pair of guide plates 550, the electrode tabs 120 are positioned so as to be close to the side surface of the terminal 510, such that the welding process may be easily performed.

Further, the connection mold 500 may have an insertion groove 560 and a through-hole 561 formed at both sides each thereof in the length direction, the insertion groove having a nut 570 inserted thereinto, and the upper cap 600 may have a fixing hole 620 formed at both sides thereof in the length direction to thereby be coupled to the nut 570 by a bolt 571 at the outer side of the upper cap 600, the fixing hole corresponding to the through-hole 561. That is, since the connection mold 500 may be made of a plastic resin, as shown in FIG. 8, the nut 570 made of a metal material is insertedly coupled to the insertion groove 560 and is covered by the upper cap 600. Then, the bolt 571 is used to pass through the fixing hole 620 and the through-hole 561 at the outer side of the upper cap 600 so as to be coupled to the nut 570, such that the upper cap 600 may be firmly fixed to the connection mold 500.

In addition, it is preferable that the connection mold 500 and the upper cap 600 may be made of a plastic material for electrical insulation, and the lower cap 400 may be made of various materials such as plastic or a metal material.

Further, the inner side of the lower cap 400 may be coated with a molten resin such as a hot melt, an adhesive agent, and the like, in order to fix the lower cap to the battery cells 100, the cell frame 200, and the case 300, and after the lower cap 400 is coupled to the lower side of the case 300, an injection inlet 410 may be formed in order to inject the molten resin, the adhesive agent, and the like.

In addition, the connection mold 500 may be provided with a gas collecting part recessed to the center of both side surfaces in the width direction, and the connection mold 500 may be provided with a gas discharge pipe which is connected to the gas collecting part to discharge the gas to the outside, and the upper cap 600 may be provided with the through-hole so that the gas discharge pipe is exposed to the outside. Accordingly, in the case in which the gas is generated by a defect of the battery cell 100, the discharged gas may be collected to the upper side of the battery cells 100 to be discharged to the outside of the second battery module through the gas discharge pipe.

Further, both side surfaces of the upper cap 600 in the width direction are provided with a protrusion 630 and a groove 640, such that when a battery pack is configured by stacking a plurality of secondary battery modules, a position to be coupled to each other may be accurately determined.

The present invention is not limited to the above-mentioned embodiments but may be variously applied. In addition, it will be appreciated by those skilled in the art that various modifications and changes may be made without departing from the appended claims of the present invention.

Claims

An easily assembled all-in-one secondary battery module comprising:

two battery cells having electrode tabs formed at one side thereof and stacked in parallel with each other;

a cell frame interposed between the two battery cells and having an electrode body of the battery cells installed at an inner side thereof;

a case having opened both sides to receive the battery cells therein, the battery cells being coupled to both sides of the cell frame;

a lower cap coupled to the opened one side of the case and coupled to an opposite side to a side at which the electrode tabs are positioned;

a connection mold inserted between facing electrode tabs of the two battery cells to thereby be coupled to the cell frame and having a plurality of terminals formed at one side thereof, the terminals being connected to the electrode tabs; and

an upper cap coupled to the opened other side of the case to which the lower cap is coupled and having a cut-part formed therein so that the terminals of the connection mold are exposed to the outside.
The easily assembled all-in-one secondary battery module of claim 1, wherein the cell frame includes an upper frame, a pair of side frames, and a lower frame and has an open part formed at an inner side thereof, and the electrode body of the battery cells is installed in the open part.
The easily assembled all-in-one secondary battery module of claim 2, wherein the pair of side frames have catching grooves formed at both sides thereof, and pouches of both sides of the two battery cells are bent in a direction in which the two battery cells face each other, the bent pouches of the battery cells being inserted into the catching grooves of the side frames, respectively.
The easily assembled all-in-one secondary battery module of claim 2, wherein the upper frame has a hollow part formed at both sides each thereof and having an opened upper surface, each of both side surfaces of the hollow part is provided with a coupling hole, and each of both sides of a lower surface of the connection mold is provided with a hook inserted into the hollow part of the upper frame to thereby be coupled to the coupling hole.
The easily assembled all-in-one secondary battery module of claim 2, wherein the electrode tab of the battery cells protrudes upwardly of the upper frame, and the terminals of the connection mold are bent from an upper surface thereof to one side surface or both side surfaces thereof.
The easily assembled all-in-one secondary battery module of claim 2, wherein the side frame protrudes outwardly of a lower portion of the pouch of the battery cells in a state in which the battery cells are coupled to the cell frame.