KR20090056027A - Battery pack employed with top cap mounting ptc device thereon - Google Patents

Abstract

A battery pack is provided to maximally utilize an upper space of a pack by mounting a PCT device on a depressed receiving portion and to efficiently improve the safety of battery while raising volume density. A battery pack comprises a battery cell where an electrode assembly(110) of a positive electrode/separation film/negative electrode structure is accommodated with electrolyte inside the metal can(130); and a protection circuit module(150) electrically connected to the battery cell. A depressed acceptance section(200) is formed in a top cap(120) combined in the top opening of the metal can. A PTC element(400) is mounted on the depressed acceptance section.

Description

Battery Pack Embeded with Top Cap Mounting PTC Device thereon

The present invention relates to a battery pack including a top cap on which a PTC element is mounted, and more particularly, to a battery cell and a protection circuit module (PCM) mounted on the battery cell in an electrically connected state to the battery cell. The rectangular top cap coupled to the open upper end of the metal can is formed with a space ('recession type receiving portion') recessed to a predetermined depth, and the recessed receiving portion has one side. It provides a battery pack characterized in that the PTC element is electrically connected to the PCM and the other side is electrically connected to the battery cell electrode terminal.

As the development and demand for mobile devices increases, the demand for secondary batteries as a source of energy is increasing rapidly. Among these secondary batteries, a lot of researches are being conducted on commercially available lithium secondary batteries with high energy density and high discharge voltage. It is used.

In particular, the lithium secondary battery is classified into a cylindrical battery, a square battery, a pouch type battery, and the like according to its appearance, and may be classified into a lithium ion battery and a lithium ion polymer battery according to the type of electrolyte. Due to the recent trend toward miniaturization of mobile devices, there is an increasing demand for thinner rectangular batteries and pouch-type batteries.

However, in the conventional lithium secondary battery, when a large current flows within a short time due to overheating, overcharge, external short circuit, nail penetration, local crush, etc., the battery is heated by IR heating. Risk of ignition / explosion. As the temperature of the battery rises, the reaction between the electrolyte and the electrode is accelerated. As a result, heat of reaction is generated to further increase the temperature of the battery, which in turn accelerates the reaction between the electrolyte and the electrode. Thus, the temperature of the battery rises rapidly, which in turn accelerates the reaction between the electrolyte and the electrode. Due to such a vicious cycle, a thermal runaway phenomenon in which the temperature of the battery rises rapidly occurs, and when the temperature rises to a certain level or more, the battery may ignite. In addition, as a result of the reaction between the electrolyte and the electrode, gas is generated to increase the battery internal pressure, and the lithium secondary battery explodes above a certain pressure. The risk of ignition / explosion can be said to be the most fatal drawback of lithium secondary batteries.

Therefore, essential considerations for the development of a lithium secondary battery are to ensure safety. As an effort to secure such safety, a method of mounting an element outside the cell is being discussed.A PTC element, a CID element, a protection circuit for controlling voltage and current, and a change in battery breakdown voltage using temperature change are discussed. Safety Vents, etc. are used for this.

Among them, PTC (Positive Temperature Coefficient) is electrically connected between an electrode assembly of a battery cell and an external input / output terminal, and maintains a low resistance at a normal operating temperature, and flows a current through abnormal current such as overcurrent or high temperature. In the state, the resistance increases rapidly with temperature rise, and flows only a small current or a small amount of current, thereby suppressing an increase in battery internal pressure due to overheating.

In the battery pack equipped with such PTC, for example, a PCM having an external input / output terminal connected to a positive electrode terminal and a negative electrode terminal through a nickel plate, and a PTC element having a nickel plate attached to the upper and lower surfaces, respectively, It consists of a structure electrically connected to the electrode terminal of the PCM and the battery cell.

In order to assemble the battery pack having such a structure, a number of welding operations are required to electrically connect the PTC element, the PCM, and the electrode terminals. Furthermore, since the PTC element must be connected to the PCM and the battery cell, a long length of nickel is required. Since the plate should be used, and the nickel plate must be bent to form a shape in which the PCM is mounted on the battery cell, a dead space corresponding to such a bending space is generated, and the volume density of the battery is relatively small.

Therefore, there is a high demand for a technology capable of effectively mounting a PCT element having a predetermined volume on the top of the battery pack without reducing the volume density of the battery pack.

Accordingly, an object of the present invention is to solve the problems of the prior art as described above and the technical problems that have been requested from the past.

After extensive research and various experiments, the inventors of the present application form a space in the top cap recessed to a predetermined depth, where one side is electrically connected to the PCM and the other side is electrically connected to the battery cell electrode terminal. In the case of mounting the PTC device connected to the device, it was confirmed that the space at the top of the battery pack can be effectively utilized, so that the volume density of the battery can be relatively improved, and the present invention was completed.

Accordingly, the battery pack according to the present invention includes a battery cell in which an electrode assembly having a cathode / separation membrane / cathode structure is sealed inside of a metal can with an electrolyte, and is mounted on the battery cell in an electrically connected state. Consists of a protection circuit module (PCM), the rectangular top cap coupled to the open top of the metal can is formed with a space ('recession type receiving portion') of the type recessed to a predetermined depth, The recessed accommodating part includes a PTC device having one side electrically connected to the PCM and the other side electrically connected to the battery cell electrode terminal.

The battery pack having such a structure is mounted in a recessed accommodating part formed by utilizing an unnecessary space inside a battery cell, so that the occupied space for mounting the battery pack can be minimized and the upper space of the battery pack is provided. Can be used efficiently. Therefore, since a compact and compact battery pack can be manufactured, there is an advantage that the volume density of the battery can be ultimately increased.

As defined above, the PTC device has one side electrically connected to the PCM and the other side electrically connected to the battery cell electrode terminal. Accordingly, since the PCM and the battery cell electrically connected to the external input / output terminals are electrically connected to each other via the PTC element, the PTC element cuts off the current of the PCM circuit when the temperature inside the battery rises. The connection to the terminal can be disconnected.

An electrical connection method between the PTC element and the battery cell electrode terminal and / or the PCM is not particularly limited, and may be directly coupled or may be coupled through a separate conductive connection member. The connection member may be a variable conductive material. , Preferably nickel plate.

The electrode terminal may be a battery case itself. In one preferred embodiment, the battery case is made of a metal can, and is electrically connected to the positive electrode tab or the negative electrode tab of the electrode assembly to form one electrode terminal (a). You may be doing

As described above, when the battery case itself forms the electrode terminal a and the recessed accommodating part is formed by deforming the top cap, the recessed accommodating part also becomes the electrode terminal a. Accordingly, the PTC device may be electrically connected to the electrode terminal a by having its bottom surface directly coupled to the bottom surface of the recessed accommodating portion. Such a connection structure is sometimes referred to hereinafter as the 'first embodiment'.

As such, when the PTC element is directly coupled to the recessed accommodating part, there is an advantage in that the number of conductive connection members can be reduced. The lower surface of the PCT device and the recessed receiving unit are not particularly limited, and may be formed through various methods such as conductive bonding, welding, and soldering, and may be preferably achieved by soldering.

In addition, the electrode terminal may be an electrode terminal (b) that is electrically insulated from the battery case and has an electrode having a polarity opposite to the electrode connected to the battery case. The electrical connection between the electrode terminal (b) and the PTC element can be achieved through a separate conductive connection member, and this connection structure is sometimes referred to as a 'second embodiment' below.

In a specific example, as in the first embodiment, when the recessed accommodating portion is the electrode terminal a, and the PTC element is to be electrically connected to the electrode terminal b, an insulating film is attached to the recessed accommodating portion. Thereafter, a PTC device may be mounted on the insulating film to electrically insulate the electrode terminal a. The combination of the PTC element and the electrode terminal (b) can be achieved through a separate conductive connection member. At this time, of course, the conductive connecting member should also be electrically insulated from the electrode terminal (a). Such electrical insulation may be achieved, for example, with an insulating film, resin, rubber or an insulating coating layer.

On the other hand, the PTC element and the PCM may be electrically connected to the upper surface of the PTC element by a conductive connection member, the connection member is not particularly limited as long as it is a variable conductive material can be varied, preferably a nickel plate. .

One of the important features of the present invention is that the PTC element is mounted on the recessed housing formed in the top cap as defined above.

In general, a rectangular or cylindrical battery is mounted by mounting an electrode assembly inside a metal can, mounting an insulating member on an open top thereof, and sealing the top cap again by welding it. Before the welding process of the top cap, one electrode terminal (eg, negative electrode tab) of one of the electrode assemblies is welded to the bottom of the protruding terminal of the top cap, and the other electrode terminal (eg, positive electrode tab) of the electrode assembly is top The process of welding to the cap itself is carried out.

Hereinafter, a vertical cross-sectional view and a partial enlarged view of the side surface of the battery cell manufactured by this process will be exemplarily described with reference to FIGS. 1 and 2.

Referring to these drawings, the electrode assembly 41 is mounted on the housing portion of the battery case 40, the insulating member 30 is mounted on the upper end of the electrode assembly 41, and the cathode of the electrode assembly 41 is mounted. The tab 42 is drawn out through the opening 33 which is drilled in the insulating member 30. Meanwhile, the top cap assembly 16 includes a top cap 10 coupled to the top of the metal can, a gasket 12 mounted on the top cap 10, and a terminal plate 14 mounted below the top cap 10. And a protruding terminal connecting member 11 attached to the top cap 10 in an insulated state by the insulating plate 15 and the gasket 12.

Therefore, the battery cell 50 is manufactured by attaching the electrode assembly 41 and the insulating member 30 to the battery case 40 and then combining the top cap assembly 16. In the assembly process of the battery 50, while the top cap 10 is positioned at an angle of about 90 degrees or more to the open upper end of the battery case 40, the negative electrode tab 42 is disposed on the lower portion of the top cap 10. After welding to the mounted terminal plate 14, the negative electrode tab 42 is bent. Finally, the top cap 10 is positioned in parallel with the open upper end of the battery case 40 and then welded to the battery case 40 to be coupled.

Since the battery cell 50 manufactured as described above uses the negative electrode tab 42 having a rather long length so as to be in contact with the terminal plate 14, the negative electrode tab 42 is bent to form an upper end or an upper portion of the electrode assembly 41. A predetermined separation space L is formed between the upper end of the insulating member 30 and the lower end of the top cap 10.

Accordingly, in the present invention, the recessed accommodating portion is formed in the spaced space L inevitably generated between the electrode assembly 41 and the top cap 10, thereby effectively utilizing the inner space of the upper part of the battery cell.

The shape of the recessed accommodating portion is not particularly limited as long as it is a shape in which the PCT element can be mounted. Such a recessed accommodating portion has a structure in which the PCT element can be easily introduced without pressing the electrode assembly formed under the top cap.

The height of the recessed accommodating portion may be appropriately adjusted within a range of the space L formed by the top surface of the electrode assembly and the bottom surface of the top cap so as not to contact the electrode assembly, preferably 0.1 to 1.0 mm, more preferably. Preferably it may be formed to a height of 0.3 to 0.6 mm.

The method of forming the recessed accommodating part may be various and is not particularly limited. In one preferred example, the recessed accommodating part may be formed by plastic deformation of a portion of the top cap to a predetermined depth. For example, the recessed accommodating portion may be formed by deep drawing so as to be indented downward with a predetermined depth in the manufacturing process of the top cap.

However, in the case of forming the recessed accommodating portion by deep drawing, if the height is too large, the tensile strain becomes large, the edge becomes thin, and the crack is generated inside the material, so that the stretched portion may be greatly deteriorated or the air breaks. It may occur and cause a defect of the product, it may be formed to a height of 1.0 mm or less.

In another preferred example, the recessed accommodating part may have a structure in which a sealing plate-shaped member is coupled to a lower end surface of the through hole formed by bending a corresponding portion of the top cap downward to a predetermined depth.

In the case of forming the recessed accommodating part in this manner, there is an advantage that it can be formed at a greater height than the deep drawing method. The joining of the bottom face of the downwardly bent through-hole and the sealing plate-shaped member can be preferably achieved by welding.

The height of the recessed accommodating part may be appropriately determined in a range in which the sealing plate-shaped member does not come into contact with the electrode assembly, and may be formed, for example, at a height of 0.5 to 2.0 mm, preferably 0.6 to 1.5 mm.

The material of the sealing plate-shaped member is not particularly limited, and may be the same as or different from the material of the battery case, and may be a conductive material or an insulating material.

For example, as in the first embodiment, when the battery case corresponds to the electrode terminal (a), and the PTC element is to be connected to the electrode terminal (a), the sealing plate-like member is the same as the battery case or Conductive materials showing similar physical properties can be used. In addition, as in the second embodiment, when the electrode terminal (b) insulated from the battery case and the PTC element is to be connected, an insulating material may be used.

The battery pack according to the present invention is not particularly limited as long as it includes a PCM connected with a battery cell.

In one preferred embodiment, the battery pack, the insulating mounting member is mounted on the top cap of the battery cell and the PCM is mounted on top, and the insulating is coupled to the upper end of the battery cell while wrapping the insulating mounting member in the PCM mounted state Further comprising a cap; The top cap is provided with a pair of protruding electrode terminals (first protruding electrode terminal and second protruding electrode terminal) respectively connected to the positive electrode and the negative electrode of the electrode assembly, and the insulating mounting member and the PCM Through grooves corresponding to the protruding electrode terminals are respectively formed, and the protruding electrode terminals are inserted into and fixed in the through holes of the insulating mounting member and the PCM, thereby fixing the insulating mounting member and the PCM to the battery cell. It may be a structure made of a combination of.

That is, the coupling of the battery pack component is achieved in that the pair of protruding electrode terminals are inserted into and fixed in the through holes of the insulating mounting member and the protection circuit module. Therefore, the battery pack can be made by assembling in a simple coupling method, there is an advantage that the mechanical fastening, simplifying the manufacturing process, can achieve a very stable coupling structure against external shock, vibration, and the like.

In the battery pack having such a structure, the recessed accommodating part may be formed at a portion where the protruding electrode terminals are not formed, and the PTC element may be electrically connected to the recessed accommodating part itself or the protruding electrode. It may be electrically connected to any one of the terminals.

Electrical connection between the PTC element and the protruding terminal may be achieved through a separate conductive connecting member, and the conductive connecting member may be coupled to the protruding terminal by welding or the like, but between the protruding terminal and the gasket. It can also be achieved by inserting in. Details thereof will be described later with reference to the drawings.

An end of the protruding electrode terminal may be fixed to the protective circuit module by rolling it in a state protruding to a predetermined length on the upper surface of the protective circuit module.

The protruding electrode terminals may be, for example, conductive conductive rivet structures, and are not particularly limited as long as they are easily inserted into the through holes of the protective circuit module and the insulating mounting member. , Oval or square.

Further, the material of the protruding electrode terminal is not particularly limited as long as it is a material having high conductivity as the electrode terminal. Preferably, Cu, Ni, and / or Cr plated steel, stainless steel, aluminum, Al alloy, Ni alloy, Cu alloy or Cr alloy. If the protruding electrode terminal is formed integrally with the top cap, it is of course made of the same material as the top cap.

On the other hand, the protruding electrode terminals may serve to additionally facilitate the manufacture of the battery cell and simplify the structure, in addition to the role of fixing the protective circuit module and the insulating mounting member to the top of the battery cell. It may be made of a structure. For example, at least one of the protruding electrode terminals may have a hollow structure including a through passage communicating with an inside of the battery case. The through passage may be used as an electrolyte injection hole for injecting an electrolyte after mounting an electrode assembly in a battery case during a battery cell manufacturing process.

The protruding electrode terminals may be variously applied regardless of the type and shape of the battery cell. For example, in the case of a square battery cell, the first protruding electrode terminal may be electrically connected to the top cap. The second protruding electrode terminal may be connected to the positive electrode, and may be connected to the negative electrode of the battery cell in an electrically insulated state from the top cap.

In the above structure, preferably, the top cap is formed with a through hole; The first protruding electrode terminal is integrally formed in the forming process of the top cap by pressing; The second protruding electrode terminal includes a plate-shaped body, an upper extension vertically extending upwardly at an upper portion, and a lower extension portion inserted into a through hole of the top cap and vertically extending downwardly at the lower portion of the main body. At the interface between the second protruding terminal and the through hole of the top cap, an electrically insulating gasket for mutual insulation is interposed, and the end portion of the lower extension part is rolled to couple the protruding electrode terminal to the top cap. .

By the coupling structure of the top cap and the protruding electrode terminals as described above, the electrode terminals can be more easily and stably coupled to the top cap, and the upper extension portion and the lower extension portion of the protruding electrode terminals are a protection circuit for the battery cell. The combination of the module and the insulating mounting member can be more firmly and stably maintained.

An adhesive may be added between the top cap and the insulating mounting member so that the insulating mounting member can be mounted to the top cap more stably.

The battery pack according to the present invention may be variously applied regardless of the type and appearance of the battery cell. Preferably, the battery pack may be a so-called rectangular lithium secondary battery in which an electrode assembly is embedded in a rectangular metal can.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings, but the scope of the present invention is not limited thereto.

3 is an enlarged partial schematic view of a top cap portion of a battery cell according to an embodiment of the present invention, Figures 4 and 5 are each a battery pack equipped with a PCM and PTC element in the battery cell of Figure 3 In the upper vertical cross-sectional schematic diagrams according to the first and second embodiments of the present invention are respectively shown.

First, referring to FIG. 3, a negative electrode terminal 500 protrudes upward in the top cap 120 mounted on the top surface of the battery cell 130, and a PTC element is formed at one side of the top cap 120. In order to be mounted, the recessed receiving part 200 which is indented downward to a predetermined depth d is formed.

4 illustrates a structure in which a PTC device 400 is connected to a positive electrode terminal according to the first embodiment of the present invention. Referring to FIG. 4, the battery case 130 is formed of a metal can, and a cathode tab (not shown) of the electrode assembly 110 is coupled to form a cathode terminal by itself, and a tower connected thereto. The cap 120 also becomes a positive terminal. The negative electrode tab 111 protrudes upward in the center portion of the upper surface of the electrode assembly 110, and the bent negative electrode tab 111 is connected to the negative electrode terminal 500. Due to the bending of the negative electrode tab 111, a predetermined separation space L is formed between the top surface of the electrode assembly 110 and the top cap 120. For reference, in the drawing, for convenience of description, the negative electrode tab 111 is expressed as being bent in the lateral direction, but as shown in FIG. 1, the negative electrode tab may be bent in the front or rear direction of the battery cell.

The recessed accommodating part 200 may be formed by plastically deforming a part of the top cap 120 by a deep drawing method. As described above, the recessed accommodating part 200 formed by deforming the top cap 120 itself, which is the anode terminal, becomes the anode terminal. Therefore, by coupling the PTC device 400 to the recessed accommodating portion 200 by direct soldering or the like, coupling with the positive terminal of the battery cell can be easily achieved. In this case, electrical connection between the PTC device 400 and the PCM 150 may be achieved by welding the connection member 420 attached to the top surface of the PTC device 400 with the PCM 150.

In contrast, an example in which the PTC device 400 is connected to the cathode terminal 500 is illustrated in FIG. 5. Referring to FIG. 5, since the PTC device 400 needs to be electrically insulated from the recessed accommodating part 200, which is an anode terminal, the PTC element 400 may be electrically insulated from the insulating film, resin, rubber, and insulating tape. The insulating member 411 may be interposed between the PTC element 400 and the recessed accommodating part 200. As described above, in the state in which the insulating member 411 is interposed, the electrical connection between the PTC device 400 and the negative electrode terminal 500 is made through the connection member 430 attached to the lower surface of the PTC device 400. Electrical connection between the 400 and the PCM 150 is made through a connecting member 420 attached to the top surface of the PTC device 400.

6 schematically illustrates an example in which the structure of the recessed accommodating part of the battery pack according to FIG. 4 is modified. For reference, except for the structure of the recessed accommodating part of FIG. 6, the same elements as in FIG. 4 are used except for the same components as in FIG. 4, and a detailed description thereof will be omitted.

The recessed accommodating portion 201 has a sealing plate-like member 220 welded to a lower end surface of the through hole 210 formed by bending downwardly from an upper end surface of the top cap 120 to a predetermined depth D. Are combined. Since the recessed accommodating part 201 is easier to adjust the height than the recessed accommodating part 200 of FIG. 4, the recessed accommodating part 201 may be formed with a relatively large depth. On the other hand, the depth of the recessed accommodating portion 201 is preferably adjusted within the height of the separation space (L; see FIG. 4) of the upper end of the battery cell in terms of efficiently utilizing the unnecessary space inside the battery cell.

When the sealing plate-shaped member 210 is made of the same or similar conductive material as the top cap 120, the sealing plate-shaped member 210 may be used as a positive electrode terminal, thereby directly coupling the PTC device 400 to the sealing plate-shaped member 120, thereby providing a battery cell. Electrical connection with the

In addition, when the sealing plate-shaped member 210 is made of an insulating material, when the PTC element 400 is to be connected to the negative electrode terminal 500, the PTC element 400 does not have to be interposed between the insulating elements. Can be mounted directly on the sealing plate-like member 120. At this time, the connection with the negative electrode terminal 500 may be achieved by attaching a separate connection member (not shown) on the lower surface of the PTC device 400 and welding it with the negative electrode terminal 500. However, the insulating member needs to be interposed between the through hole 210 formed by bending the recessed accommodating part 201 and the connection member for connection between the PTC device 400 and the negative electrode terminal 500. .

7 is an exploded perspective view schematically showing a battery pack according to another embodiment of the present invention.

Referring to FIG. 7, the battery pack 100 includes a battery cell 130 in which an electrode assembly is embedded in a battery case together with an electrolyte, a top cap 120 for sealing an open upper end of the battery case, and a protection circuit. Insulating mounting member 140 mounted on the plate-shaped protective circuit module 150, the top cap 120 of the battery cell 130, the protective circuit module 150 is mounted to the insulating mounting member 140 The wrapper is composed of an insulating cap 160 coupled to the upper end of the battery cell 130, a lower cap 170 mounted to the lower end of the battery cell 130, and the like.

The pair of protruding terminals 501 and 502 includes a first protruding electrode terminal 501 and a second protruding electrode terminal 502 which protrude upwards on both sides of an upper end of the top cap 120. . In addition, a recessed accommodating part 200 which is recessed downward in a predetermined depth is formed between the pair of protruding terminals 501 and 502 of the top cap 120 so that the PTC element 400 can be mounted. It is.

The insulating mounting member 140 may correspond to the first through holes 142 and 144 having the shape and size corresponding to the lower ends of the protruding electrode terminals 501 and 502, and the recessed accommodating part 200. The second through hole 146 having a shape is formed, and the fastening through grooves 152 and 154 having the shape and size corresponding to the upper ends of the protruding electrode terminals 501 and 502 are formed in the protection circuit module 150. ) Is formed.

The first protruding terminal 501 is connected to the positive electrode (not shown) of the battery cell 130 in an electrically connected state with the top cap 120, and the second protruding terminal 502 is the top cap 120. It is connected to the negative electrode (not shown) of the battery cell 130 in an electrically insulated state.

The combination of the insulating mounting member 140 and the protection circuit module 150 with respect to the battery cell 130 may include first protrusions having protruding electrode terminals 501 and 502 formed at both sides of the insulating mounting member 140. After inserting the through grooves 142 and 144 and the through holes 152 and 154 for fastening formed in both sides of the protection circuit module 150, the ends of the protruding electrode terminals 501 and 502 By rolling it. In addition, the coupling of the insulating mounting member 140 to the top cap 120 may be made more firm by the adhesive as needed.

The insulating cap 160 is coupled to the upper end of the battery cell 130 while wrapping the insulating mounting member 140 in the state in which the protective circuit module 150 is mounted, so as to surround the outer surface of the upper end of the battery cell 130. It extends downward to a predetermined length. The lower cap 170 is attached to the lower end of the battery cell 150.

In the battery pack 100 having such a structure, when the PTC device 400 is to be electrically connected to the positive electrode according to the first embodiment of the present invention, the recessed number forming the positive terminal of the lower surface of the PTC device 400 It can be directly coupled to the payment (200). In addition, it may be connected to the first protruding terminal 501 through a separate connection member. Meanwhile, the PTC device 400 and the PCM 150 may be electrically connected to each other through the connection member 420 attached to the top surface of the PTC device 400.

On the contrary, an example in which the PTC device 400 is electrically connected to the cathode according to the second embodiment of the present invention is schematically illustrated in FIG. 8.

Referring to FIG. 8 together with FIG. 7, an insulating mounting member 140 and a protection circuit module (140) may be formed on the top cap 120 formed integrally with the first protruding electrode terminal 501 on the battery pack 100. 150 are sequentially mounted.

The first protruding electrode terminal 501 is formed with a through passage 5011 for injecting an electrolyte solution in a central portion thereof, and is integrally formed with the top cap 120. On the other hand, the second protruding electrode terminal 502 has its lower extension 5026 inserted and mounted in the through hole 122 of the top cap 120 from the top, and the second protruding electrode terminal 502 ) And the top cap 120 are equipped with electrically insulating gaskets 122 and 124 for mutual insulation. In addition, indentations 5023 and 5025 are formed at ends of the upper extension part 5024 and the lower extension part 5026 of the second protruding electrode terminal 502, respectively.

Therefore, the protruding end of the first protruding electrode terminal 501 and the protruding end of the second protruding electrode terminal 502 are respectively rolled, and the insulating mounting member 140 and the protective circuit module 150 are formed on the top cap. It can be fixed stably.

The PTC element 400 is a second protruding type that is a cathode terminal through a connecting member 430 attached to the lower surface of the PTC element 400 in a state where the insulating member 411 is interposed on the inner surface of the recessed accommodating part 200. It may be electrically connected to the terminal 502. In this case, the PTC device 400 and the PCM 150 may be electrically connected to each other through the connection member 420 attached to the top surface of the PTC device 400.

The connection member 430 may be coupled to the second protruding electrode terminal 502 by welding or the like, but is simply inserted between the gasket 122 and the second protruding electrode terminal 502 to be in close contact with each other. Stable electrical connection is possible. In particular, in the latter case, the welding process can be additionally omitted, and thus, the process efficiency is excellent, and there is an advantage in that a more compact battery can be manufactured since there is substantially no space wasted for mounting the connection member 430.

Although described with reference to the drawings according to an embodiment of the present invention, those of ordinary skill in the art will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

As described above, the battery pack according to the present invention can maximize the space at the top of the pack by mounting a PCT element in the recessed accommodating portion, thereby increasing the volume density of the pack and efficiently improving the safety of the battery. You can.

1 and 2 are vertical cross-sectional and partial enlarged views of a typical rectangular battery side surface;

3 is an enlarged partial schematic view of a top cap portion of a battery cell according to the present invention;

4 and 5 are top cross-sectional views of the battery pack according to the first and second embodiments of the present invention, respectively, in the battery pack including the battery cell of FIG. 3;

FIG. 6 is a schematic view of an example in which the structure of the recessed accommodating part of the battery pack according to FIG. 4 is modified;

7 is an exploded perspective view of a battery pack according to another embodiment of the present invention;

8 is a vertical cross-sectional view of the battery pack according to the second embodiment of the present invention in the battery pack according to FIG. 7.

Claims (17)

The electrode assembly having a cathode / separation membrane / cathode structure includes a battery cell sealed inside a metal can with an electrolyte, and a protection circuit module (PCM) mounted on the battery cell in an electrically connected state to the battery cell. The rectangular top cap coupled to the open top of the metal can is formed with a space ('a recessed accommodating portion') formed at a predetermined height, and one side of the recessed accommodating portion is formed in the PCM. A battery pack, characterized in that the PTC element is electrically connected and the other side is electrically connected to the battery cell electrode terminal. The battery pack as claimed in claim 1, wherein the electrical connection with the battery cell electrode terminal and / or the PCM is achieved through a conductive connection member. The battery pack as claimed in claim 1, wherein the battery case is a metal can, and is electrically connected to a positive electrode tab or a negative electrode tab of the electrode assembly to form one electrode terminal (a). The battery pack as claimed in claim 3, wherein the lower surface of the PTC element is directly connected to the lower surface of the recessed accommodating part and electrically connected to the electrode terminal (a). The battery pack according to claim 4, wherein the lower surface of the PCT element is bonded to the lower surface of the recessed accommodating part by soldering. 4. The battery pack according to claim 3, wherein the upper surface of the PTC element is electrically connected to the PCM by a conductive connecting member. The method according to claim 3, wherein the recessed accommodating portion has an insulating film attached thereto, a PTC element is mounted on the insulating film, and the lower surface of the PTC element is electrically insulated from the battery case by a conductive connection member. A battery pack, characterized in that connected to the electrode terminal (b) of the battery cell. 8. The battery pack according to claim 7, wherein an upper surface of the PTC element is connected to the PCM by another connecting member. The battery pack according to claim 1, wherein the recessed accommodating portion is formed by plastically deforming a part of the top cap by pressing. The battery pack according to claim 1, wherein the height of the recessed accommodating portion is 0.1 to 1.0 mm. The battery pack according to claim 10, wherein the height of the recessed accommodating portion is 0.3 to 0.6 mm. The method of claim 1, The PCM is mounted on top, and further includes an insulating mounting member mounted to the top cap of the battery cell, and an insulating cap coupled to the upper end of the battery cell while wrapping the insulating mounting member in the state where the PCM is mounted; The top cap is provided with a pair of protruding electrode terminals (first protruding electrode terminal and second protruding electrode terminal) respectively connected to the positive electrode and the negative electrode of the electrode assembly, and the insulating mounting member and the PCM Through grooves corresponding to the protruding electrode terminals are respectively formed, and the protruding electrode terminals are inserted into and fixed in the through holes of the insulating mounting member and the PCM, thereby fixing the insulating mounting member and the PCM to the battery cell. Battery pack characterized in that the combination is made. 13. The battery pack according to claim 12, wherein an end portion of the protruding electrode terminal is rolled in a state protruding to a predetermined length on an upper surface of the PCM and fixed to the PCM. 13. The method of claim 12, wherein at least one of the protruding electrode terminals has a hollow structure including a through passage communicating with the inside of the battery case, and the through passage is sealed by a metal ball after being used as an electrolyte injection hole. A battery pack characterized by the above. The battery cell of claim 12, wherein the first protruding electrode terminal is connected to the positive electrode of the battery cell in an electrically connected state with the top cap, and the second protruding electrode terminal is electrically insulated from the top cap. Battery pack, characterized in that connected to the negative electrode. The method of claim 12, wherein the top cap is formed with a through hole, The first protruding electrode terminal is integrally formed in the forming process of the top cap by pressing, The second protruding electrode terminal includes a plate-shaped body, an upper extension vertically extending upwardly at an upper portion, and a lower extension portion inserted into a through hole of the top cap and vertically extending downwardly at the lower portion of the main body. A battery characterized in that the end of the lower extension portion is rolled to couple the protruding electrode terminal to the top cap in a state in which an electrically insulating gasket for mutual insulation is interposed between the second protruding terminal and the through hole of the top cap. pack. The battery pack as claimed in claim 12, wherein the insulating mounting member is coupled to the battery cell by an adhesive method.

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