KR101669123B1 - Pouch type secondary battery and battery module including the same - Google Patents

Abstract

A secondary battery according to the present invention is a pouch type secondary battery comprising: an electrode assembly having a positive electrode plate and a negative electrode plate disposed at a predetermined distance; A pouch exterior member having an internal space formed therein for accommodating the electrode assembly and the electrolyte in the internal space; An electrode tab extending from the electrode assembly; And at least a part of which is formed in a cylindrical or prismatic shape, and has an electrode lead having one end connected to the electrode tab and the other end exposed to the outside of the pouch outer casing.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a pouch type secondary battery and a battery module including the same,

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a secondary battery, and more particularly, to a secondary battery including an electrode lead having an improved structure that facilitates connection and disconnection of a bus bar and a battery module including the same.

2. Description of the Related Art Generally, a secondary battery is a battery capable of being charged and discharged unlike a primary battery which can not be charged, and is widely used in electronic devices such as mobile phones, notebook computers, camcorders, and electric vehicles. Particularly, the lithium secondary battery has a larger capacity than a nickel-cadmium battery or a nickel-hydrogen battery, which is widely used as a power source for electronic equipment, and has a high energy density per unit weight.

These lithium secondary batteries mainly use a lithium-based oxide and a carbonaceous material as a cathode active material and an anode active material, respectively. The lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate each coated with such a positive electrode active material and a negative electrode active material are disposed with a separator interposed therebetween, and an outer casing, that is, a battery case, for sealingly storing the electrode assembly together with the electrolyte solution.

Meanwhile, the lithium secondary battery can be classified into a can type secondary battery in which an electrode assembly is embedded in a metal can, and a pouch type secondary battery in which an electrode assembly is embedded in a pouch of an aluminum laminate sheet, depending on the shape of the casing.

The secondary battery is generally manufactured through a process in which a liquid electrolyte, that is, an electrolyte is injected and the casing is sealed while the electrode assembly is housed in the casing.

FIG. 1 is an exploded perspective view showing a configuration of a conventional pouch type secondary battery, and FIG. 2 is a combined view of the pouch type secondary battery of FIG.

As shown in FIGS. 1 and 2, the pouch type secondary battery generally comprises an electrode assembly 20 and a pouch case 30 that accommodates the electrode assembly 20.

Here, the electrode assembly 20 has a basic structure of a positive electrode plate, a negative electrode plate, and a separator interposed therebetween, and is accommodated in an inner space formed in the pouch case 30. [ At this time, the pouch exterior member 30 may be composed of an upper pouch 31 and a lower pouch 32. A sealing part S is provided on the outer peripheral surface of the upper pouch 31 and the lower pouch 32, The inner space in which the electrode assembly 20 is accommodated can be sealed by adhering the parts S to each other.

On the other hand, one or more positive electrode tabs 21 and negative electrode tabs 22 may extend from the positive electrode plate and the negative electrode plate, respectively. The positive electrode tab 21 and the negative electrode tab 22 are connected to the electrode leads 10, that is, the positive electrode lead 11 and the negative electrode lead 12, And some of them are exposed to the outside of the pouch case 30 to provide an electrode terminal to be electrically connected to an external configuration of the secondary battery, such as another secondary battery or an external device.

In recent years, secondary batteries are widely used not only in small-sized devices such as portable electronic devices, but also in medium to large-sized devices such as automobiles and electric power storage devices. Particularly, as carbon energy is getting depleted and the interest in the environment is increasing, attention is focused on hybrid cars and electric cars worldwide, including the US, Europe, Japan, and Korea. The most important components in such hybrid vehicles and electric vehicles are battery packs that give drive power to vehicle motors. Since hybrid vehicles and electric vehicles can obtain the driving force of the vehicle through charging and discharging of the battery pack, the fuel efficiency is higher than that of the vehicle using only the engine, and the users are increasingly increasing in terms of not discharging or reducing pollutants. to be. The battery pack of the hybrid vehicle or the electric vehicle includes a plurality of secondary batteries, and the plurality of secondary batteries are connected in series and in parallel to improve capacity and output.

The serial connection or the parallel connection between the secondary batteries may be determined in various forms depending on the output, capacity, structure, etc. of the battery pack in consideration of the device to which the battery pack is applied. Accordingly, the secondary batteries are connected in various serial and parallel shapes to constitute a battery module, which may be included in one or more battery packs.

As such, in order for a plurality of secondary batteries to be connected in series and / or in parallel, bus bars are generally used. That is, by connecting a plurality of electrode leads provided in each of the plurality of secondary batteries to the same polarity or between the different polarity bus bars, the plurality of secondary batteries can be electrically connected to each other. Here, the combination of the conventional bus bar and the electrode lead is mainly performed by welding.

However, when the electrode lead and the bus bar are coupled by welding, there is a problem that it is very difficult to remove or add one or a part of the secondary battery in the battery pack. For example, when the performance of any one of the plurality of secondary batteries included in the battery pack deteriorates, it is necessary to replace the secondary battery with another secondary battery. In order to do this, the secondary battery must first be detached from the battery pack. Since the electrode lead and the bus bar are fixed by welding, the electrode lead must be cut to separate the secondary battery. However, this process is very troublesome, and a part of the electrode lead may remain in the bus bar, which may interfere with welding the electrode lead of the new secondary battery, and may increase the weight of the battery pack. In addition, there is a possibility that a part of the electrode lead remaining on the bus bar comes into contact with the electrode lead or the bus bar of the other polarity and causes an internal short circuit in the battery pack. In addition, the electrode lead of the secondary battery to be added in order to add a new secondary battery to the battery pack after the deteriorated secondary battery is deteriorated in the conventional structure is welded to the bus bar, which is also troublesome and difficult .

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a secondary battery, a battery module including the secondary battery, A battery pack including the battery module, and an automobile.

Other objects and advantages of the present invention will become apparent from the following description, and it will be understood by those skilled in the art that the present invention is not limited thereto. It will also be readily apparent that the objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.

According to an aspect of the present invention, there is provided a secondary battery comprising: an electrode assembly including a positive electrode and a negative electrode disposed at a predetermined distance; A pouch exterior member having an internal space formed therein for accommodating the electrode assembly and the electrolyte in the internal space; An electrode tab extending from the electrode assembly; And at least a part of which is formed in a cylindrical or prismatic shape, and has an electrode lead having one end connected to the electrode tab and the other end exposed to the outside of the pouch outer casing.

Preferably, the electrode lead is formed at least in a cylindrical shape or a prism shape at the other end.

Preferably, the electrode lead is formed in a plate shape in which a portion of the electrode lead interposed in the sealing portion of the pouch exterior material is thinner than the other end.

Preferably, the electrode lead is connected to the electrode lead of another pouch type secondary battery by a bus bar, and a cylindrical or prismatic portion is inserted into an insertion groove formed in the bus bar to be fastened to the bus bar .

Also, preferably, the electrode lead has a fastening groove for inserting the protrusion of the bus bar into a portion formed in a cylindrical or prismatic shape.

Preferably, at least two of the coupling grooves are formed in the electrode lead.

Preferably, the electrode lead has an outer surface of a cylindrical or prismatic portion formed of an electrically nonconductive material, and the surface of the coupling groove is made of an electrically conductive material.

Preferably, the electrode lead is formed with a thread for fastening the bus bar to an outer surface of a cylindrical or prismatic portion.

Also, preferably, the electrode leads are formed in the shape of an elliptical pole having an overall length in a width direction longer than a thickness direction length.

In order to accomplish the above object, a battery module according to the present invention includes an electrode assembly having a positive electrode plate and a negative electrode plate disposed with a predetermined distance therebetween, a pouch outer case for storing the electrode assembly and the electrolyte in the inner space, A plurality of electrode pads extending from the electrode assembly and at least a part of which is formed in a cylindrical or prismatic shape and having electrode leads connected at one end to the electrode tabs and exposed at the other end to the outside of the pouch case, ; And a bus bar connecting between the electrode leads of the different pouch type secondary batteries, and a coupling portion coupled with a cylindrical or prismatic portion of the electrode lead.

Preferably, the electrode lead is formed at least in a cylindrical shape or a prismatic shape at the other end, and the bus bar is formed in a shape corresponding to a cylindrical portion or a prismatic portion of the electrode lead.

Preferably, the electrode lead is formed in a plate shape in which a portion of the electrode lead interposed in the sealing portion of the pouch exterior material is thinner than the other end.

Also, preferably, the coupling portion of the bus bar is formed in a groove shape, and a cylindrical portion or a prismatic portion of the electrode lead is inserted into the coupling portion.

Preferably, the coupling portion of the bus bar includes a projection, and the electrode lead has a coupling groove formed in a cylindrical or prismatic shape corresponding to the projection, and the projection is inserted into the coupling groove .

Also, preferably, the bus bar has two or more protrusions, and the electrode lead has two or more of the fastening grooves.

Preferably, the electrode lead has a cylindrical or prismatic outer surface formed of an electrically non-conductive material, and the surface of the coupling groove is made of an electrically conductive material, and the bus bar has an outer surface made of an electrically non- And the protrusions are made of an electrically conductive material.

Preferably, a thread is formed in correspondence with the surface of the portion of the electrode lead formed in a cylindrical or prismatic shape and the surface of the coupling portion of the bus bar.

Also, preferably, the electrode leads are formed in the shape of an elliptical pole having an overall length in a width direction longer than a thickness direction length.

According to another aspect of the present invention, there is provided a battery pack comprising at least two secondary batteries according to the present invention.

According to another aspect of the present invention, there is provided an automobile comprising at least two secondary batteries according to the present invention.

According to an aspect of the present invention, the electrode lead and the bus bar can be joined without welding.

Therefore, according to this aspect of the present invention, the electrode lead of the secondary battery can be easily disassembled from the bus bar. Therefore, according to the present invention, some of the secondary batteries included in the battery module can be easily removed from the battery module.

Further, according to this aspect of the present invention, the electrode lead of the secondary battery can be easily coupled to the bus bar. Therefore, according to the present invention, a new secondary battery can be easily added to the battery module.

Particularly, according to this aspect of the present invention, when a problem occurs such as deterioration in performance of a part of the plurality of secondary cells constituting the battery module, the process of replacing the corresponding secondary cell with another new secondary battery Can be easily performed.

According to an aspect of the present invention, since the contact area between the electrode lead of the secondary battery and the bus bar can be increased, the electrical or physical connection between the electrode lead and the bus bar can be more stably maintained, Can be reduced.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the description of the invention given below, serve to further the understanding of the technical idea of the invention, And should not be construed as limiting.
1 is an exploded perspective view showing a configuration of a conventional pouch-type secondary battery.
Fig. 2 is a combined view of the pouch type secondary battery of Fig. 1. Fig.
3 is an exploded perspective view schematically showing a configuration of a secondary battery according to an embodiment of the present invention.
Fig. 4 is a combined view of the secondary battery shown in Fig. 3. Fig.
5 is a view showing a partial configuration of a section taken along the line A-A 'in FIG.
6 is an exploded perspective view schematically showing a configuration of a secondary battery according to another embodiment of the present invention.
7 is a coupling diagram of the secondary battery shown in Fig.
8 is a view showing a partial configuration of a section taken along line B-B 'in Fig.
9 is a perspective view schematically showing a configuration of a battery module according to an embodiment of the present invention.
10 is a cross-sectional view schematically showing a configuration in which one electrode lead and a bus bar are combined in the configuration of FIG.
11 is a cross-sectional view schematically showing the configuration of an electrode lead and a bus bar according to another embodiment of the present invention.
12 is a cross-sectional view schematically showing the configuration of an electrode lead and a bus bar according to still another embodiment of the present invention.
13 is a cross-sectional view schematically showing the structure of an electrode lead and a bus bar according to still another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be interpreted in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined.

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention and do not represent all the technical ideas of the present invention. Therefore, It is to be understood that equivalents and modifications are possible.

FIG. 3 is an exploded perspective view schematically showing a configuration of a secondary battery according to an embodiment of the present invention, and FIG. 4 is a combined view of the secondary battery of FIG.

3 and 4, a secondary battery 100 according to the present invention includes an electrode assembly 110, a pouch casing 120, an electrode tab 130, and an electrode lead 140.

The electrode assembly 110 may be configured such that at least one positive electrode plate and at least one negative electrode plate are disposed with a separator interposed therebetween. At this time, the electrode assembly 110 is housed in the pouch case 120 in a state where a plurality of positive plates and a plurality of negative plates are alternately stacked or housed in the pouch case 120 in a state where one positive and negative plates are wound .

The electrode plates of the electrode assembly 110 are formed as a structure in which a current collector is coated with an active material slurry. The slurry may be formed by stirring a granular active material, an auxiliary conductor, a binder, a plasticizer, . In addition, each of the electrode plates may have an unoccupied portion where no slurry is applied, and an electrode tab 130 corresponding to each electrode plate may be formed on the uncoated portion.

The pouch case 120 has a concave internal space, and the electrode assembly 110 and the electrolytic solution are accommodated in the internal space. In particular, the pouch exterior member 120 may include an outer insulating layer made of a polymer material, an inner adhesive layer, and a metal layer interposed between the outer insulating layer and the inner adhesive layer. Here, aluminum may be used as a material of the metal layer of the pouch exterior member 120, but the present invention is not limited thereto.

The pouch exterior material 120 may include an upper pouch 121 and a lower pouch 122. 3 and 4, the inner space in which the electrode assembly 110 can be housed may be formed in both the upper pouch 121 and the lower pouch 122, And may be formed only on one of the pouches 122. When the electrode assembly 110 is housed in the storage space of the upper pouch 121 and the lower pouch 122, the sealing portion S of the upper pouch 121 and the sealing portion S of the lower pouch 122 The adhesive layers located on the inner side can be adhered to each other by thermal fusion or the like so that the inner space is sealed.

The electrode tabs 130 may extend from the electrode assembly 110 and include a positive electrode tab and a negative electrode tab. Here, the positive electrode tab may extend from the non-coated portion of the positive electrode plate, and the negative electrode tab may extend from the non-coated portion of the negative electrode plate. The electrode tabs 130 may be formed in a plate shape, such as a shape in which the electrode plate is cut or a shape in which a separate metal plate is attached to the electrode plate.

In addition, the positive electrode tab and the negative electrode tab may be respectively provided in the secondary battery 100, but they may be provided in two or more. For example, when only one positive electrode plate and one negative electrode plate are included in the electrode assembly 110 of the secondary battery 100, one each of the positive electrode tab and the negative electrode tab may be included. Alternatively, in this case, a plurality of positive electrode tabs and negative electrode tabs may be respectively included. Meanwhile, when the positive electrode plate and the negative electrode plate are respectively included in the electrode assembly 110 of the secondary battery 100, a plurality of positive electrode tabs and negative electrode tabs may be included. In this case, .

The electrode lead 140 is a component that electrically connects the secondary battery to another external secondary battery or another device. In particular, in the battery module, a plurality of secondary batteries may be electrically connected to each other through a bus bar, in which case the electrode leads 140 may be configured to directly contact the bus bars. Since the electrode lead 140 is a component for electrical connection between the inside and the outside of the secondary battery, at least a part of the electrode lead 140 may be made of an electrically conductive material such as a metal.

The electrode lead 140 may include a positive electrode lead and a negative electrode lead and may extend from the inside of the pouch case 120 to the outside of the pouch case 120 and between the sealing portions of the pouch case 120, Can be intervened. The electrode lead 140 is connected to the electrode tab 130 having one end, that is, an inner end located inside the pouch case 120 and extending from the electrode assembly 110.

In order to stably maintain the contact state, the contact portion between the electrode tab 130 and the electrode lead 140 is fixed by welding. In order to stably maintain the contact state of the electrode tab 130 and the electrode lead 140, . Meanwhile, the secondary battery may include a plurality of positive electrode tabs and a plurality of negative electrode tabs. In this case, the plurality of positive electrode tabs may be in contact with one positive electrode lead in a state of being overlapped with each other, It can be contacted to one negative electrode lead.

The other end of the electrode lead 140 is exposed to the outside of the pouch case 120. One end of the electrode lead 140 is positioned inside the pouch case 120 and connected to the electrode tab 130 and the other end of the electrode lead 140 is connected to the outside of the pouch case 120 And can be connected to the bus bar.

Particularly, in the secondary battery according to the present invention, at least a part of the electrode lead 140 may be formed in a cylindrical shape or a prism shape. In other words, the electrode lead of the secondary battery is generally formed in the form of a plate having a thin thickness. However, the electrode lead 140 of the secondary battery according to the present invention is formed in the form of a rod having a thick thickness partially or entirely.

Preferably, the electrode lead 140 may have a cylindrical shape or a prism shape at least at its other end. This will be described in more detail with reference to FIG.

5 is a view showing a partial configuration of a section taken along the line A-A 'in FIG.

5, the electrode lead 140 has a central portion interposed between the upper pouch 121 and the lower pouch 122, and a portion interposed between the upper pouch 121 and the lower pouch 122 The left portion is located on the inner side of the pouch case 120 and the right side is located on the outer side of the pouch case 120. [ The electrode lead 140 is disposed on the outside of the pouch outer covering material 120 and the portion L 2 between the sealing portions of the pouch outer covering material 120 and the pouch outer covering material 120. And a portion L3. 3 to 5, the portion (L3) of the electrode lead 140 exposed to the outside of the pouch case 120, It may be formed in a cylindrical or prismatic shape.

Here, the columnar or prismatic shape means a column having a circular or square shape in cross section when the electrode lead 140 is cut in the direction perpendicular to the length, that is, in the thickness direction. Here, the thickness direction means the up-and-down direction when the large surface is positioned on the upper side and the lower side of the pouch type secondary battery as in the up-down direction in Fig.

When the electrode lead 140 has a circular cross section, the circular shape may include not only a cylindrical shape having a constant radius from the center but also an ellipse having a constant radius from the center. In the case where the electrode lead 140 has a rectangular cross section, the rectangular shape may include a triangular or more triangular shape such as a triangle, a square, or a pentagon.

According to this configuration of the present invention, the coupling structure of the electrode lead 140 and the bus bar can be more easily achieved. That is, the other end of the electrode lead 140 located outside the pouch case 120 may be coupled to the bus bar for connection with another secondary battery. In the case of the electrode lead 140 according to the present invention, And is formed thicker than the conventional electrode lead, so that it can be fastened to the bus bar without welding. Details of the connection structure of the electrode lead 140 and the bus bar will be described later.

More preferably, the electrode lead 140 may be formed in a plate shape in which a portion of the electrode lead 140 interposed in the sealing portion of the pouch case 120 is thinner than the other end. 5, at least a portion of the portion L3 of the electrode lead 140 located on the outer side of the pouch outer casing 120 may be formed in a cylindrical shape or a prismatic shape, The portion L2 interposed between the sealing portions of the lower pouch 122 may be formed to be thinner than the thickness of the portion formed in the column shape in the L3 portion.

According to this embodiment of the present invention, a part of the electrode lead 140 is formed in a cylindrical shape or a prismatic shape to facilitate the fastening structure with the bus bar, thereby preventing the sealing force of the pouch case 120 from being weakened . That is, when the electrode lead 140 is formed in a cylindrical or prismatic shape as a whole, the sealing force of the electrode lead 140 is weakened due to the thickened thickness of the electrode lead 140 at the sealing portions of the upper pouch 121 and the lower pouch 122 Problems can arise. However, if the electrode lead 140 is formed of a thin plate so as to be interposed between the sealing portions of the pouch case 120, the sealing force of the pouch case 120 The weakening problem can be solved.

The electrode lead 140 may be formed in a plate shape that is thinner than the other end with respect to a portion L1 that is located inside the pouch case 120, particularly, a portion that is in contact with the electrode tab 130. [ Since the portion of the electrode lead 140 which contacts the electrode tab 130 is formed in the form of a plate having a flat and wide surface, the electrode tab 130 and the electrode lead 140 The contact can be made more stably. The electrode tab 140 may be welded while being in contact with the electrode lead 140. When the end of the electrode lead 140 contacting the electrode tab 130 is formed in a plate shape, The welding process of the electrode tab 130 and the electrode tab 130 can be made easier and the fixing force by welding can be improved.

It is preferable that the maximum thickness of the electrode lead 140 is thinner than the maximum thickness of the pouch type secondary battery. In other words, the thickness (indicated by t1 in Fig. 5) of the other end formed in the shape of a cylinder or prism in the electrode lead 140 is preferably thinner than the overall thickness (indicated by t2 in Fig. 5) of the pouch type secondary battery.

According to such a configuration of the present invention, when the pouch type secondary battery is stacked, the cylindrical or rectangular columnar portion of the electrode lead 140 does not protrude from the pouch type secondary battery, thereby facilitating the stacking of the pouch type secondary battery, Interference or contact between the electrode leads 140 can be prevented.

Also, it is preferable that the maximum width of the electrode lead 140 is 10% to 30% of the maximum width of the pouch type secondary battery. The width of the electrode lead 140 is such that when the side of the pouch type sheathing member 120 protruding from the electrode lead 140 is viewed in a state in which a large surface is positioned above and below the pouch type secondary battery, And the length of one electrode lead 140 in the left-right direction. The electrode lead 140 according to the present invention is formed such that the width (indicated by w1 in Fig. 4) of the other end portion formed in a cylindrical or prismatic shape is 10% or less, as a whole width (represented by w2 in Fig. 4) To 30%.

According to this configuration of the present invention, even when the positive electrode lead and the negative electrode lead are located on the same side in one pouch type secondary battery, interference or contact between the positive electrode lead and the negative electrode lead can be prevented, .

In the above embodiment, only the portion L3 of the electrode lead 140 exposed to the outside of the pouch case 120 is formed as a cylindrical or prismatic shape. However, the present invention is not limited thereto. It is not.

FIG. 6 is an exploded perspective view schematically showing a configuration of a secondary battery according to another embodiment of the present invention, and FIG. 7 is a combined view of the secondary battery of FIG. 6.

6 and 7, the electrode lead 140 is formed not only in the form of a column, that is, in the shape of a rod, but also in the sealing of the pouch case 120 And a portion located in the interior of the pouch exterior member 120 as a whole.

According to this configuration of the present invention, it is not necessary to make the configuration of the electrode leads 140 partly different from each other, so that the manufacturing of the electrode leads 140 and the manufacturing process of the secondary batteries using such electrode leads 140 can be made easier have.

In particular, in the structure in which the electrode leads 140 are formed as a column as a whole, the electrode leads 140 may be formed in an elliptical column shape. This will be described in more detail with reference to FIG.

8 is a view showing a partial configuration of a section taken along line B-B 'in Fig.

Referring to FIG. 8, the electrode lead 140 may be formed in the shape of an elliptical pole whose cross-sectional shape is an ellipse whose width direction length r1 and thickness direction length r2 are different from each other. In particular, it is preferable that the electrode lead 140 has an elliptical shape in which the sectional shape of the electrode lead 140 is longer than the thickness direction length r2 in the width direction r1.

According to this configuration of the present invention, since the electrode lead 140 is formed in a columnar shape, the sealing force of the pouch type secondary battery can be prevented from being weakened. That is, when the electrode leads 140 are interposed between the sealing portions of the pouch case 120, when the electrode leads 140 are formed in a prismatic shape or in the form of a garden column, the electrode leads 140, A gap may be formed between the casing members 120, so that sealing of the pouch casing member 120 may be difficult. However, when the electrode lead 140 is formed in the shape of an elliptical column as in the above embodiment, the contact between the electrode lead 140 and the pouch exterior member 120 is curved so that the electrode lead 140 can be well contacted. Particularly, when the thickness of the electrode lead 140 is smaller than the width of the electrode lead 140, the curved surface of the pouch outer cover 120 can be formed in a gentle shape, It is possible to prevent a problem that sealing is not performed properly.

The electrode leads 140 may be formed in a cylindrical or prismatic shape so that the portions L1 and L3 located inside and outside the pouch case 120 are formed in the shape of a cylinder or a prism, The portion (L2) sandwiched between the sealing portions can be configured in the form of a thin plate. In this case, the electrode lead 140 may be configured such that the thickness of the intermediate portion interposed between the sealing portions of the pouch outer cover 120 is thinner than the thickness of the one end and the other end. According to this embodiment of the present invention, it is possible to prevent the sealing strength of the pouch outer casing 120 from being weakened due to the thick thickness of the electrode leads 140 and to prevent the electrode leads 140 from being inward or outward of the pouch outer casing 120 It is possible to prevent movement in the direction.

9 is a perspective view schematically showing a configuration of a battery module according to an embodiment of the present invention.

Referring to FIG. 9, a battery module according to the present invention includes a pouch type secondary battery 100 and a bus bar 200 according to the present invention.

The pouch type secondary battery 100 may include more than two battery modules. However, in FIG. 9, only two pouch-type secondary batteries 100 are shown for convenience of explanation. Since the pouch type secondary battery 100 has been described above, the detailed description of the configuration of the pouch type secondary battery 100 will be omitted here.

The bus bar 200 is a component for electrically connecting between the pouch type secondary batteries 100 and may be directly contacted with the electrode leads 140 of each secondary battery 100. At least two bus bars 200 may be provided in the battery module.

In particular, the bus bar 200 according to the present invention includes a coupling portion 210. Here, the coupling portion 210 may be a portion of the electrode lead 140 of the pouch type secondary battery 100 where the electrode lead 140 is connected to a cylindrical or prismatic portion. That is, the other end of the electrode lead 140 of the pouch type secondary battery 100 may be coupled to the coupling portion 210 of the bus bar 200.

For this purpose, the coupling part 210 of the bus bar 200 may be formed in a shape corresponding to a cylindrical or prismatic portion of the electrode lead 140. For example, when the electrode lead 140 of the secondary battery is formed in an elliptical column shape, the coupling portion 210 of the bus bar 200 may be formed in an elliptical column shape corresponding to the cylindrical shape. When the electrode lead 140 of the secondary battery is formed into a prismatic shape, such as a triangular prism shape, the coupling portion 210 of the bus bar 200 may be formed into a triangular prism shape corresponding to this shape.

Preferably, the coupling portion 210 of the bus bar 200 may be formed in a groove shape. That is, the bus bar 200 may be formed in a groove shape in which the coupling part 210 is concave than other parts. The electrode lead 140 may be coupled to the bus bar 200 by being coupled to the coupling part 210 formed in the groove shape. This will be described in more detail with reference to FIG. 10 together with FIG.

10 is a cross-sectional view schematically showing a configuration in which one electrode lead 140 and bus bar 200 are combined in the configuration of FIG. Fig. 10 is a side sectional view of a portion of Fig.

For example, as shown in FIGS. 9 and 10, the other end of the electrode lead 140, that is, the side end coupled with the bus bar 200 may be formed in an elliptical column shape. The bus bar 200 may have an elliptical columnar groove as the coupling portion 210. The size of the groove may be similar to or the same as the size of the other end of the electrode lead 140 formed in the shape of an elliptic column, can do. For example, the vertical length of the elliptical groove formed in the bus bar 200 may be the same as the vertical length of the other end of the electrode lead 140.

The other end of the electrode lead 140 may be inserted into the coupling part 210 of the bus bar 200 formed in a groove shape. In this case, the surface of the electrode lead 140 and the surface of the coupling portion 210 of the bus bar 200 can be in contact with each other, and electrical connection is made between the electrode lead 140 and the bus bar 200 .

10, when the other end of the electrode lead 140 is inserted into the coupling portion 210 of the bus bar 200, the upper surface, the lower surface, and the outer surface of the other end of the electrode lead 140 The right side surface) may be in contact with the upper surface, the lower surface, and the inner surface of the coupling portion 210 of the bus bar 200. Electrical connection between the electrode lead 140 and the bus bar 200 can be achieved through surface contact between the electrode lead 140 and the coupling portion 210.

Meanwhile, since the electrode leads 140 provided in the plurality of secondary cells can be connected to the bus bar 200, the plurality of secondary cells can be electrically connected through the bus bar 200.

More preferably, the coupling part 210 of the bus bar 200 includes projections, and the electrode leads 140 may have a coupling groove formed in a shape corresponding to the projections on the surface of the cylindrical or prismatic portion have. In this case, the projections are inserted into the fastening grooves, so that the bus bars 200 and the electrode leads 140 can be fastened or electrically connected. This will be described in more detail with reference to FIG.

11 is a cross-sectional view schematically showing the configuration of the electrode lead 140 and the bus bar 200 according to another embodiment of the present invention.

Referring to FIG. 11, the coupling part 210 of the bus bar 200 may have a protrusion 211 protruding from an inner surface thereof. In addition, the electrode lead 140 may have a coupling groove 141 formed on the surface of the other end, in particular, a cylindrical or prismatic portion. At this time, the coupling groove 141 may be formed in a shape corresponding to the shape of the projection 211 provided in the coupling portion 210 of the bus bar 200. For example, when the projections 211 of the bus bar 200 are formed in a cylindrical shape, the coupling grooves 141 of the electrode leads 140 are formed so that the cylindrical projections 211 can be inserted and fastened, . ≪ / RTI >

The coupling between the protrusion 211 of the bus bar 200 and the coupling groove 141 of the electrode lead 140 is a physical coupling force when the coupling between the coupling portion 210 of the bus bar 200 and the electrode lead 140 And the like. For example, when the other end of the electrode lead 140 is inserted into the coupling portion 210 of the bus bar 200, a gap between the surface of the coupling portion 210 of the bus bar 200 and the other end surface of the electrode lead 140 The other end of the electrode lead 140 is electrically connected to the bus bar 200 by the frictional force due to the contact and the frictional force due to the contact between the surface of the projection 211 of the bus bar 200 and the surface of the coupling groove 141 of the electrode lead 140. [ (Not shown).

The protrusions 211 are provided on the bus bar 200 and the coupling grooves 141 are formed on the other ends of the electrode leads 140 as in the above embodiment. The engaging grooves 141 of the lid 140 can be made to take charge of electrical connection therebetween.

11, the groove of the bus bar 200, that is, the coupling part 210 itself is made of an electrically nonconductive material, and the protrusion 211 formed on the coupling part 210 is made of an electrically conductive material Lt; / RTI > Also, the other end of the electrode lead 140 may be formed of an electrically non-conductive material on the outer surface, and the surface of the coupling groove 141 may be formed of an electrically conductive material. When the other end of the electrode lead 140 is inserted into the coupling portion 210 of the bus bar 200, the projection 211 of the bus bar 200 and the coupling groove 141 of the electrode lead 140, The bus bar 200 and the electrode lead 140 may be electrically connected to each other.

The components for electrical connection are not easily exposed to the outside of the bus bar 200 or the electrode lead 140 and thus the inside of the bus bar 200 and the electrode lead 140 The risk of short circuit and the like may be reduced. The electrode lead 140 and the bus bar 200 may be made of an electrically nonconductive material except for the coupling groove 141 of the electrode lead 140 and the protrusion 211 of the bus bar 200. [ ) Can be made of a polymer material or the like as compared with the case of using an electrically conductive material as a whole, the manufacturing easiness can be increased and the manufacturing cost can be reduced.

11 shows a structure in which the protrusions 211 of the bus bar 200 and the coupling grooves 141 of the electrode leads 140 are elongated in the same direction as the direction of insertion and removal of the electrode leads 140 However, the present invention is not limited to the configuration of the projections 211 and the coupling grooves 141.

12 is a cross-sectional view schematically showing the configuration of an electrode lead 140 and a bus bar 200 according to another embodiment of the present invention.

12, protrusions 211 protruding in the vertical direction are formed in the coupling portion 210 of the bus bar 200 and the other ends of the electrode leads 140 are formed with positions and shapes corresponding to the protrusions 211 The fastening groove 141 can be formed. In this embodiment, when the other end of the electrode lead 140 moves in the right direction and is inserted into the coupling portion 210 of the bus bar 200, as shown by the arrow, 210 may be inserted into the coupling groove 141 formed at the other end of the electrode lead 140. That is, in this structure of the present invention, the protrusion 211 and the coupling groove 141 are vertically aligned with each other, so that the electrode lead 140 and the bus bar 200 are perpendicular to the inserting direction of the bus bar 200 . Therefore, when the other end of the electrode lead 140 is separated from the coupling portion 210 of the bus bar 200 in the left direction, the coupling structure between the projection 211 and the coupling groove 141 So that the fastening force between the electrode lead 140 and the bus bar 200 can be further strengthened.

12, the protrusions 211 of the bus bar 200 may be formed more than one in one coupling part 210. As shown in FIG. Further, two or more coupling grooves 141 of the electrode lead 140 may be formed to correspond thereto. According to this configuration of the present invention, two or more coupling structures between the protrusion 211 of the bus bar 200 and the coupling groove 141 of the electrode lead 140 are secured, so that electrical connection and / Can be strengthened and maintained more stably.

In the above embodiment, the protrusion 211 is provided on the bus bar 200 and the coupling groove 141 is formed on the electrode lead 140. However, in the opposite embodiment, the bus bar 200 And the protrusion 211 may be formed on the electrode lead 140. The protrusion 211 may be formed on the electrode lead 140. [ This will be described in more detail with reference to FIG.

13 is a cross-sectional view schematically showing the configuration of the electrode lead 140 and the bus bar 200 according to still another embodiment of the present invention. However, for convenience of explanation, the outer shape of the other end of the electrode lead 140 is shown as it is.

Referring to FIG. 13, the electrode lead 140 may have a threaded protrusion 142 formed on the outer surface of a portion formed at the other end, that is, a cylindrical or prismatic shape. The bus bar 200 may have a thread groove 212 corresponding to the thread projection 142 formed on the outer surface of the electrode lead 140. The connection between the electrode lead 140 and the bus bar 200 can be prevented through the threaded protrusion 142 formed in the electrode lead 140 and the threaded groove 212 formed in the bus bar 200. [ It can be easily performed, and the fastening force can be stably secured.

In this embodiment, the coupling portion 210 of the bus bar 200 may be configured to be rotatable, as indicated by the arrow in Fig. According to such a configuration, in order to connect the electrode lead 140 to the bus bar 200, the coupling portion 210 of the bus bar 200 may be rotated without rotating the electrode lead 140 or the secondary battery itself, The electrode connection between the electrode lead 140 and the bus bar 200 can be easily realized.

The battery pack according to the present invention may include at least two secondary batteries according to the present invention. In particular, the battery pack according to the present invention may include at least one battery module according to the present invention. In addition to the battery module, the battery pack may further include a case for covering the battery module, and various devices for controlling charge and discharge of the battery module, such as a BMS, a current sensor, a fuse, and the like.

The secondary battery according to the present invention, particularly the battery module according to the present invention, can be applied to an automobile such as an electric car or a hybrid car. That is, the automobile according to the present invention may include the secondary battery according to the present invention.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It will be understood that various modifications and changes may be made without departing from the scope of the appended claims.

In the present specification, terms indicating upward, downward, leftward, and rightward directions are used, but these terms are for convenience of explanation only, and may vary depending on the position of the object or the position of the observer. Lt; / RTI >

100: secondary battery
110: electrode assembly
120: Pouch Exterior Material
121: upper pouch
122: Lower pouch
130: electrode tab
140: electrode lead
141: fastening groove
142: Thread projection
200: bus bar
210:
211: projection
212: thread groove

Claims (20)

An electrode assembly in which a positive electrode plate and a negative electrode plate are disposed with a predetermined distance therebetween;
And a metal layer interposed between the outer insulating layer and the inner adhesive layer, wherein an inner space is formed to receive the electrode assembly and the electrolyte in the inner space, and the upper and lower pouches Wherein the inner space of the upper pouch and the inner adhesive layer of the sealing portion of the lower pouch are adhered to each other to seal the inner space.
An electrode tab extending from the electrode assembly; And
At least a part of which is formed in a cylindrical or prismatic shape and a part of which is interposed between the sealing part of the upper pouch and the sealing part of the lower pouch so that one end is connected to the electrode tab inside the pouch case, Exposed electrode lead
Wherein the pouch type secondary battery comprises a pouch type secondary battery. The method according to claim 1,
Wherein the electrode lead has at least one end formed in a cylindrical shape or a prismatic shape. 3. The method of claim 2,
Wherein the electrode lead is formed in a plate shape in which a portion of the electrode lead interposed in the sealing portion of the pouch exterior member is thinner than the other end. The method according to claim 1,
Wherein the electrode lead is connected to an electrode lead of another pouch type secondary battery by a bus bar and a portion formed in a cylindrical shape or a prism shape is inserted into an insertion groove formed in the bus bar to be fastened to the bus bar. Secondary battery. 5. The method of claim 4,
Wherein the electrode lead has a fastening groove for inserting a projection of the bus bar into a portion formed in a cylindrical or prismatic shape. 6. The method of claim 5,
Wherein at least two of the coupling grooves are formed in the electrode lead. 6. The method of claim 5,
Wherein the electrode lead has an outer surface of a cylindrical or prismatic portion formed of an electrically nonconductive material and the surface of the coupling groove is made of an electrically conductive material. 5. The method of claim 4,
Wherein the electrode lead is formed with a thread for fastening the bus bar to an outer surface of a cylindrical or prismatic portion. The method according to claim 1,
Wherein the electrode lead is formed in an elliptical pole shape having a length in the width direction as a whole greater than a length in the thickness direction. An electrode assembly in which a positive electrode plate and a negative electrode plate are arranged at a predetermined distance, an outer insulating layer and an inner adhesive layer made of a polymer material, and a metal layer interposed between the outer insulating layer and the inner adhesive layer, A pouch outer casing which is formed of an upper pouch and a lower pouch and is configured to seal the inner space by bonding the sealing part of the upper pouch and the inner bonding layer of the sealing part of the lower pouch to the electrode assembly and the electrolyte, And at least a part of the electrode tab is formed in a cylindrical or prismatic shape and a part of the electrode tab is interposed between the sealing part of the upper pouch and the sealing part of the lower pouch so that one end is connected to the electrode tab inside the pouch case, Wherein the outer surface of the pouch exterior material A plurality of pouch-type secondary batteries having polar leads; And
A bus bar having an electrode lead connected to the electrode leads of the different pouch type secondary batteries and having a coupling portion coupled with a cylindrical or prismatic portion of the electrode lead,
The battery module comprising: 11. The method of claim 10,
Wherein the electrode lead is formed at least in a cylindrical or prismatic shape at the other end, and the bus bar is formed in a shape corresponding to a cylindrical portion or a prismatic portion of the electrode lead. 12. The method of claim 11,
Wherein the electrode lead is formed in a plate shape in which a portion of the electrode lead interposed between the sealing portion of the pouch exterior material is thinner than the other end. 11. The method of claim 10,
Wherein the coupling portion of the bus bar is formed in a groove shape, and a cylindrical portion or a prismatic portion of the electrode lead is inserted into the coupling portion. 14. The method of claim 13,
Wherein the coupling portion of the bus bar has a projection, and the electrode lead is formed in a cylindrical or prismatic shape with a coupling groove corresponding to the projection, and the projection is inserted into the coupling groove. module. 15. The method of claim 14,
Wherein the bus bar includes at least two protrusions, and the electrode leads are formed with at least two fastening grooves. 15. The method of claim 14,
Wherein the outer surface of the electrode lead is formed of an electrically non-conductive material and the surface of the coupling groove is made of an electrically conductive material, the outer surface of the bus bar is made of an electrically non-conductive material, Is made of an electrically conductive material. 14. The method of claim 13,
Wherein a thread is formed in a shape corresponding to a surface of a cylindrical portion or a prismatic portion of the electrode lead and a surface of a coupling portion of the bus bar. 14. The method of claim 13,
Wherein the electrode leads are formed in the shape of an elliptical pole having an overall length in a width direction longer than a thickness direction length. A battery pack comprising a secondary battery according to any one of claims 1 to 9. A vehicle comprising the secondary battery according to any one of claims 1 to 9.

Images