KR101783914B1 - Pouch type secondary battery and battery pack including the same - Google Patents

Abstract

The present invention discloses a pouch type secondary battery and a battery pack including the pouch type secondary battery, wherein the electrode assembly has a shape corresponding to the shape of the inner space of the pouch exterior member, thereby increasing the size of the electrode assembly and improving the capacity and output. The pouch type secondary battery according to the present invention comprises: an upper pouch and an upper pouch, each having an inner space formed therein; and a pouch exterior member having a shape in which the outer pouch of the upper pouch and the outer pouch of the lower pouch are sealed; And a plurality of electrode plates accommodated in the inner space of the pouch exterior member in a stacked manner with a separator sandwiched therebetween, and electrode tabs extending from the electrode plate, wherein a size of a predetermined electrode plate among the electrode plates stacked at the center is different And an electrode assembly larger than the size of the electrode plate.

Description

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

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a secondary battery technology, and more particularly, to a pouch-type secondary battery having improved energy density due to an improvement in structure of an electrode assembly, a battery pack including the same, and an application device thereof.

2. Description of the Related Art In recent years, demand for portable electronic products such as notebook computers, video cameras, and portable telephones has been rapidly increased, and electric vehicles, storage batteries for energy storage, robots, and satellites have been developed in earnest. Are being studied actively.

The secondary rechargeable batteries are nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium secondary batteries. Among them, lithium secondary batteries have almost no memory effect compared to nickel- It is very popular because of its low self-discharge rate and high energy density.

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.

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

FIG. 1 is an exploded perspective view showing a configuration of a conventional pouch type secondary battery, and FIG. 2 is an assembled perspective view of the pouch type secondary battery of FIG. 3 is a cross-sectional view taken along the line A-A 'in Fig.

As shown in FIGS. 1 to 3, the pouch type secondary battery generally comprises an electrode assembly 10 and a pouch case 20 for accommodating the electrode assembly 10.

Here, the electrode assembly 10 includes an electrode plate, that is, a positive electrode plate and a negative electrode plate, and a separator may be interposed between the positive electrode plate and the negative electrode plate. However, the separator is not shown in the figure for convenience of explanation.

The positive electrode plate and the negative electrode plate may each include at least one electrode tab 11, that is, a positive electrode tab and a negative electrode tab. The positive electrode tab and the negative electrode lead are respectively coupled to the electrode leads 12, that is, the positive electrode lead and the negative electrode lead, and a part of the positive electrode lead and the negative electrode lead are exposed to the outside of the pouch case 20, For example, an electrode terminal so as to be electrically connected to another secondary battery or an external device.

In particular, in the pouch type secondary battery, the electrode assembly 10 may be configured in a stacked manner, as shown in Figs. 1 and 3. Here, the stacked electrode assembly refers to an electrode assembly having a plurality of positive electrode plates and negative electrode plates, and a plurality of positive electrode plates and negative electrode plates stacked alternately with a separator interposed therebetween.

The pouch case 20 may be composed of an upper pouch 21 and a lower pouch 22. The electrode assembly 10 and the electrolytic solution are accommodated in the inner space formed by the upper pouch 21 and the lower pouch 22 do. The upper pouch 21 and the lower pouch 22 are formed with sealing portions S on the outer circumferential surface to seal the inner space and these sealing portions S are bonded (sealed) to each other.

In order to protect the electrode assembly 10 and internal components such as the electrolyte and to improve the electrochemical properties of the electrode assembly 10 and the electrolytic solution and to improve heat dissipation, . The aluminum thin film is interposed between the insulating layers formed of an insulating material in order to secure electrical insulation between the electrode assembly 10 and the components inside the secondary battery such as the electrolyte and other components outside the secondary battery.

In recent years, as the application range of such a pouch-type secondary battery has been expanded, a pouch-type secondary battery is widely used not only in a small portable device such as a smart phone but also in a medium- or large-sized device such as an electric vehicle or a power storage device including a hybrid vehicle . In addition to this, the range of application is expanded, and the performance of the secondary battery is more desperately required. Typically, there is a great demand for a rechargeable battery having a small energy-saving capacity and an improved power density. However, the conventional pouch type secondary battery has a problem in that it can not be regarded as an optimized secondary battery in terms of energy density.

Particularly, as shown in Fig. 3, the pouch outer casing used in the pouch type secondary battery generally has a hexagonal shape in cross section, and the electrode assembly generally has a substantially rectangular cross-sectional shape. As a result, as shown by B in FIG. 3, an empty space in which the electrode assembly does not exist in the outer periphery of the pouch exterior member, that is, in the vicinity of the sealing portion, can be formed as a dead space. Of course, when the pouch exterior material is formed, it is possible to reduce the dead space when the angle as shown by C in FIG. 3 is reduced to a right angle. However, in this case, the problem of damage such as whitening phenomenon or crack generation in the pouch exterior material Lt; / RTI >

Therefore, in the case of the conventional secondary battery, improvement in energy density is limited due to such dead space.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a pouch type secondary battery capable of increasing the size of the electrode assembly and improving the capacity and output by allowing the electrode assembly to have a shape corresponding to the inner space shape of the pouch- A battery and a battery pack including the same are provided.

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 upper pouch having an inner space formed therein and a lower pouch, wherein the upper pouch and the outer periphery of the lower pouch are sealed A configured pouch exterior material; And a plurality of electrode plates accommodated in the inner space of the pouch exterior member in a stacked manner with a separator sandwiched therebetween, and electrode tabs extending from the electrode plate, wherein a size of a predetermined electrode plate among the electrode plates stacked at the center is different And an electrode assembly larger than the size of the electrode plate.

Preferably, the electrode assembly is formed to have the largest electrode plate stacked on the layer where the sealing portions of the upper pouch and the lower pouch are located.

Also, preferably, the electrode assembly has a largest electrode plate located in the center layer.

Preferably, the electrode assembly gradually increases in size from the outer layer toward the center layer.

Preferably, the electrode tab includes an insulating member on at least a part of an inner surface facing the electrode plate.

Also preferably, at least some of the electrode tabs are attached to the inner space wall surface of the pouch exterior material.

Also, preferably, the pouch outer casing is sealed with four outer peripheral portions, and the electrode assembly is formed such that an electrode plate larger than the size of the other electrode plates protrudes in all four outer circumferential portions of the pouch outer casing.

Preferably, the electrode assembly has an average distance from the side where the electrode tabs are provided to the inner walls of the electrode pads and the pouch case, the average distance from the side where the electrode tabs are not provided to the inner wall of the electrode plate and the pouch case .

According to another aspect of the present invention, there is provided a battery pack including the pouch type secondary battery.

According to another aspect of the present invention, there is provided an automobile including the pouch type secondary battery.

According to an aspect of the present invention, in the pouch type secondary battery, the electrode assembly has a shape corresponding to the inner space of the pouch case, thereby reducing the space (dead space) in which the electrode assembly is not present in the pouch case, Can be increased.

Therefore, according to this aspect of the present invention, even if they have the same size, the size of the electrode assembly housed therein can be increased, so that the pouch type secondary battery with improved capacity and output can be provided.

Particularly, in the case of a middle- or large-sized battery pack, since a plurality of pouch-type secondary batteries are included, a dead space reduction and an electrode assembly size increase for one pouch-type secondary battery results in a very large capacity and an increase in output .

In addition, according to one aspect of the present invention, it is possible to improve the performance of the pouch type secondary battery constructed in various forms.

In addition, since the output and capacity can be improved without reducing the angle indicated by C in FIG. 3 in manufacturing the outer case of the pouch, problems such as the damage of the outer case of the pouch due to the reduction of the angle (C) There is no concern.

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 augment the technical spirit 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.
2 is an assembled perspective view of the pouch type secondary battery of FIG.
3 is a cross-sectional view taken along the line A-A 'in Fig.
4 is an exploded perspective view schematically showing a configuration of a pouch type secondary battery according to an embodiment of the present invention.
5 is an assembled perspective view of Fig.
6 is a sectional view taken along the line D1-D1 'in FIG.
7 is a sectional view taken along the line D2-D2 'in Fig.
8 is an enlarged view of the portion G in Fig.
9 is a sectional view taken along the line D2-D2 'in Fig.
10 is an enlarged perspective view of the portion H1 in Fig.

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. 4 is an exploded perspective view schematically showing a configuration of a pouch type secondary battery according to an embodiment of the present invention, and FIG. 5 is an assembled perspective view of FIG.

Referring to FIGS. 4 and 5, the pouch type secondary battery according to the present invention includes a pouch case 200 and an electrode assembly 100.

The pouch exterior member 200 has a concave internal space, and the electrode assembly 100 and the electrolytic solution can be accommodated in the internal space.

In particular, the pouch exterior member 200 can be composed of an upper pouch 210 and a lower pouch 220. In this case, the concave internal space is formed by the upper pouch 210 and the lower pouch 220, (Not shown).

In addition, the pouch exterior member 200 may be configured such that the upper pouch 210 and the outer periphery of the lower pouch 220 are sealed. That is, the upper pouch 210 and the lower pouch 220 each have a sealing portion at the rim of the inner space, and the sealing portion is sealed by heat sealing or the like, so that the inner space of the pouch outer case 200 can be sealed have.

The electrode assembly 100 includes a plurality of electrode plates and electrode tabs 110 and is housed in the inner space of the pouch case 200. Here, the electrode plate is composed of a positive electrode plate and a negative electrode plate, and the electrode assembly 100 may be stacked such that the positive electrode plate and the negative electrode plate have a wide surface facing each other with the separator therebetween. That is, the electrode assembly 100 may be configured such that the positive electrode plate and the negative electrode plate are alternately stacked with the separator interposed therebetween, and the positive electrode plate and the negative electrode plate are spaced apart from each other by a predetermined distance.

The positive electrode plate and the negative electrode plate are formed as a structure in which the active material slurry is applied to the current collector. The slurry is usually formed by stirring the granular active material, auxiliary conductor, binder, plasticizer, etc. with the solvent added.

Each of the positive electrode plate and the negative electrode plate may be provided with a positive electrode tab and a negative electrode tab in an uncoated portion to which no active material is applied. The electrode tab 110 may extend from the electrode plate and may be formed by cutting off the electrode plate or by attaching a metal plate of the same or different material to the electrode plate. The positive electrode tab and the negative electrode tab may be connected to the positive electrode lead and the negative electrode lead, respectively, and may be exposed to the outside of the pouch case.

In the pouch type secondary battery according to the present invention, the electrode assembly 100 may include a plurality of positive electrode plates and a plurality of negative electrode plates stacked in a vertical direction. The plurality of positive electrode plates and the plurality of negative electrode plates are each provided with electrode tabs 110 and may be connected to the same electrode leads 120 by contacting the same polarities. For example, a positive electrode tab may be formed to protrude from a plurality of positive electrode plates included in the electrode assembly 100, so that a plurality of positive electrode tabs may be connected to the positive electrode lead in contact with each other. At this time, the connection between the plurality of electrode tabs 110 and / or the connection between the electrode tabs 110 and the electrode leads 120 may be performed by welding or the like.

In particular, the electrode assembly 100 according to the present invention is formed such that the size of a predetermined electrode plate among the electrode plates stacked at the center is larger than that of the other electrode plates. Here, the electrode plate laminated at the center means an electrode plate located in the inner layer rather than the electrode plate located at the outermost position. In other words, the electrode assembly 100 according to the present invention has a structure in which the electrode plates other than the uppermost layer electrode plate and the lowermost layer electrode plate, that is, the uppermost layer electrode plate and the lowermost layer electrode At least a part of the electrode plates positioned between the plates may be formed to be the largest.

This configuration will be described in more detail with reference to FIG.

6 is a sectional view taken along the line D1-D1 'in FIG. In FIG. 6, for convenience of explanation, ten electrode plates 101 are shown in a stacked form, and a separator is not shown.

6, the electrode assembly 100 may include a plurality of electrode plates 101 stacked in a vertical direction, and each of the electrode plates 101, which constitute the electrode assembly 100, And e1 to e10 electrode plates in the upper to lower direction. At this time, the electrode plate 101 positioned at the outermost layer can be regarded as an electrode plate e1 located on the uppermost layer and an electrode plate e10 located on the lowermost layer. The electrode plate 101 laminated on the central portion may be e2 to e8 other than e1 and e10. Accordingly, the electrode assembly 100 according to the present invention can be configured such that at least one of the electrode plates e2 to e8 is formed larger than the other electrode plates. For example, as shown in FIG. 6, the e5 electrode plate and the e6 electrode plate among the electrode plates stacked at the center can be formed to the greatest extent. The size of the electrode plate may mean the length of the side of the electrode plate that determines the area of the electrode plate as shown in FIG. 6 in the lateral direction.

It is preferable that the electrode assembly 100 is formed such that the electrode plate 101 stacked on the layer where the sealing portions of the upper pouch 210 and the lower pouch 220 are positioned is the largest. For example, in the embodiment of FIG. 6, the sealing portions of the upper pouch 210 and the lower pouch 220 may be located on the e5 electrode plate and the e6 electrode plate. In this case, the e5 electrode plate and the e6 electrode plate The largest size can be formed. In the case of the pouch-type secondary battery, as shown in FIGS. 3 and 6, the left and right widths of the inner space are often formed to be largest in a portion where the sealing portions of the upper pouch 210 and the lower pouch 220 are located . Therefore, in the case where the size of the electrode plate stacked on the layer where the sealing portions of the upper pouch 210 and the lower pouch 220 are located is the largest, as in the above embodiment, dead space is more effectively reduced, Can be maximized.

Also, the electrode assembly 100 may be formed such that the electrode plate 101 located on the center layer has the largest size. The upper pouch 210 and the lower pouch 220 constituting the pouch exterior member 200 are formed symmetrically with each other in many cases so that the sealing portions of the upper pouch 210 and the lower pouch 220 are vertically oriented In many cases. Therefore, when the size of the electrode plate 101 located in the center layer is maximized as in the above embodiment, the size of the electrode plate 101 laminated on the layer where the sealing portion is located becomes the largest, Can be maximized.

For example, in the embodiment of FIG. 6, the upper pouch 210 and the lower pouch 220 are formed to have the same height as the inner space. At this time, the e5 electrode plate and the e6 electrode plate, In the largest configuration, the size of the electrode plate stacked on the layer where the sealing portion is located can be maximized.

6, the electrode assembly 100 may be formed to have the largest size and the largest size. However, in the case where one electrode plate has the largest size or three or more electrode plates It is of course possible to have the largest size.

Also, preferably, the electrode assembly 100 may be configured such that the size of the electrode plate gradually increases from the outer layer to the center layer. For example, in the embodiment of FIG. 6, in the case of the electrode plates e1 to e5 located at the upper portion, the electrode plate located in the outer layer gradually increases in size toward the center layer, the electrode assembly 100 may be configured such that the relationship e3 < e4 < e5 is formed. Also, in the case of the lower electrode plates e6 to e10, the electrode plate located in the outer layer gradually increases in size from the electrode plate toward the center layer, and the relationship of e10 <e9 <e8 <e7 <e6 The electrode assembly 100 may be formed.

In many cases, the portion of the pouch exterior member 200 between the upper and lower flat portions and the sealing portion (indicated by F in Fig. 6) is formed in a somewhat inclined shape rather than a vertical direction with respect to the ground surface. This is because, if the F portion of the pouch exterior member 200 is configured to be close to vertical, whitening may occur in the bent portion of the pouch exterior member 200 and the corresponding portion may be damaged. Therefore, can do. However, if the size of the electrode plate is gradually increased from the outer layer to the center layer as in the above embodiment, the electrode assembly 100 may have a shape corresponding to the tilted shape of the F portion of the pouch case 200 . Therefore, according to this embodiment of the present invention, the size and size of the electrode assembly 100 can be increased as much as possible to improve the capacity and output of the secondary battery.

Meanwhile, in the embodiment of FIG. 6, the electrode plates e1 to e10 may each represent one positive electrode plate or one negative electrode plate. For example, the electrode plates e1, e3, e5, e7 and e9 may be positive plates, and the electrode plates e2, e4, e6, e8 and e10 may be negative plates.

Alternatively, in the embodiment of FIG. 6, the electrode plates e1 to e10 may be a structure in which at least one positive electrode plate and at least one negative electrode plate are combined. For example, each of the electrode plates e1 to e10 may be an assembly in which a positive electrode plate, a separator, a negative electrode plate, and a separator are sequentially stacked. E2, e4, e6, e8 and e10 electrode plates are assemblies in which a positive electrode plate, a separator, a negative electrode plate, a separator, a positive electrode plate and a separator are sequentially laminated, , A positive electrode plate, a separator, a negative electrode plate, and a separator in this order.

Preferably, in the electrode assembly 100, the electrode tab 110 may include an insulating member. This will be described in more detail with reference to FIGS. 7 and 8. FIG.

7 is a sectional view taken along a line D2-D2 'in FIG. 5, and FIG. 8 is an enlarged view taken along a line G in FIG. In Fig. 7, similarly to Fig. 6, it is assumed that the electrode assembly 100 is formed by stacking ten electrode plates.

Referring to FIGS. 7 and 8, a plurality of electrode plates, which are stacked on the electrode assembly 100, may each have an elongated electrode tab 110 formed thereon. At this time, the electrode tab 110 may be provided with an insulating member on at least a part of the inner surface facing the electrode plate. For example, in the embodiment of Figs. 7 and 8, in the case of the electrode tab t1, since the electrode tab t1 is formed so as to protrude to the right of the electrode plate, the left electrode plate faces the electrode plate. Therefore, in this t1 electrode tab, an insulating member may be provided on at least a part of the left surface facing the electrode plate.

The insulating member is formed of a material having electrical insulation, thereby preventing the electrode tab 110 from being electrically connected even if the electrode tab 110 physically contacts the electrode plate. 7, since the electrode plate laminated at the center portion is formed to be larger than the other electrode plates, the electrode tabs 110 and the electrode plates are stacked as much as the size of the electrode plates, The possibility of contact increases. However, if the electrode tabs 110 and the electrode tabs having different polarities are in contact with each other, for example, when the positive electrode tab extending from the positive electrode plate contacts the negative electrode plate, short-circuiting occurs internally, so that ignition or explosion of the secondary battery occurs The safety of the secondary battery can be greatly reduced. However, if an insulating member is provided on the inner surface of the electrode tab 110 facing the electrode tab 110, the electrode tabs 110 having different polarities and the electrode plates may be mutually There is no possibility of electrical connection. Therefore, according to this embodiment, the safety of the pouch type secondary battery according to the present invention can be secured.

Here, the insulating member may be formed on at least one surface of the electrode tab 110. For example, in the embodiment of Fig. 8, the electrode tab t1 may be configured such that at least a part of the left surface facing the electrode plate is coated with an insulating material. In this case, the electrode tab 110 may include a metal base layer 111 made of a metal such as aluminum, copper or nickel, and an insulating coating layer 112 made of an insulating material.

On the other hand, the coating of the electrode tab 110 of the insulating member can be implemented in various ways. For example, the insulating member may be coated by spraying an insulating material on at least one surface of a metal plate constituting the electrode tab 110, or by immersing a metal plate in a solution made of an insulating material.

In addition to this coating form, the insulating member may be provided on the surface of the electrode tab 110 in various other forms. For example, the insulating member may be in the form of an adhesive tape composed of an insulating material, and may be attached to at least one surface of the electrode tab 110. For example, in the configuration of Fig. 7, an insulating adhesive tape may be adhered to at least a part of the left surface of the electrode tab t1. In such a configuration, an advantage can be given in that the surface of the electrode tab 110 can be insulated after the electrode tab manufacturing process.

7 and 8, an insulating member is provided mainly on the electrode tab t1 which is one electrode tab 110 among the plurality of electrode tabs 110. However, the other electrode tabs 110 May also be provided with an insulating member. 7, an electrode tab 110 protruding to the left of the electrode assembly 100 may be provided with an insulating member on the right side surface facing the electrode plate, In the case of the electrode tab 110 protruding in the right direction, the insulating member may be provided on the left surface facing the electrode plate.

Also, at least some of the electrode tabs 110 may be configured to be attached to the inner space wall of the pouch case 200. This will be described in more detail with reference to FIGS. 9 and 10. FIG.

9 is a sectional view taken along a line D2-D2 'in Fig. 5, and Fig. 10 is an enlarged perspective view showing a portion H1 in Fig.

9 and 10, some or all of the electrode tabs 110 extending from the electrode plate may be configured to be attached to the inner space wall of the pouch case 200, that is, to the inner wall. For example, when ten electrode tabs 110 are provided in the electrode assembly 100 as shown in FIG. 9, four electrode tabs 110 are formed on the electrode tabs 110, And may be configured to be attached to the inner wall of the pouch exterior member 200 at the same portion.

According to this configuration of the present invention, since the electrode tab 110 is attached to the inner wall of the pouch case 200, the possibility that the electrode tab 110 contacts the electrode plate is greatly reduced. Therefore, the risk of an internal short circuit occurring due to the contact of the electrode tab 110 with the electrode plate of the other polarity in the section between the electrode plate and the electrode lead 120 can be reduced.

In the configuration in which some of the electrode tabs 110 of the plurality of electrode tabs 110 are attached to the inner wall of the pouch case 200 as in the above embodiment, the relatively long electrode tabs 110 are formed on the inner surface of the pouch case 110 200). For example, in the embodiment of FIG. 9, the electrode tab 110 may be attached to the inner wall of the pouch case 200 with respect to the electrode tab 110 extending from the four electrode plates stacked on the outer layer. This is because the probability that the electrode tab 110, which is elongated relatively long, comes into contact with the electrode plate is relatively high.

More preferably, the electrode tabs 110 can be attached to the inner space wall surface of the pouch case 200 by the adhesive tape 113. 10, when the electrode tab 110 is in contact with the inner wall of the pouch case 200, the adhesive tape 113 is adhered to the outer surface of the electrode tab 110 and the inner wall of the pouch case 200 So that the electrode tab 110 can be attached to the inner wall of the pouch case 200. According to this embodiment of the present invention, a configuration in which the electrode tab 110 is attached to the inner wall of the pouch outer casing 200 can be easily achieved, and the attachment state can be stably maintained.

Preferably, in the pouch type secondary battery according to the present invention, as shown in FIGS. 4 and 5, the pouch outer casing 200 may be configured such that four outer peripheral portions thereof are sealed. That is, the upper pouch 210 and the lower pouch 220 may have a rectangular shape when viewed from the upper side to the lower side, and may have four sides. . At this time, the upper pouch 210 and the lower pouch 220 may be configured to seal all four outer circumferential portions.

At this time, the electrode assembly 100 may be formed such that the electrode plate, which is larger than the size of the other electrode plates, protrudes in all four outer circumferential directions of the pouch case 200. That is, the electrode plate of the electrode assembly 100 is not formed in a straight line in the vertical direction, and the electrode plate having the largest size may be formed so that all four sides are protruded from other electrode plates. For example, referring to FIGS. 6 and 7, the e5 electrode plate and the e6 electrode plate are formed to have a larger size than the other electrode plates. The e5 electrode plate and the e6 electrode plate have four sides Direction can be configured to protrude from other electrode plates.

When all four outer peripheral portions of the pouch exterior member 200 are sealed, the inclined portions as indicated by F in Fig. 6 may be formed in the vicinity of the four outer peripheral portions. It is possible to increase the size of the electrode plate in all of the inclined portions of the pouch outer casing 200, and thus it may be preferable to improve the energy density.

However, the present invention is not necessarily limited to these embodiments, and the electrode assembly 100 may be configured such that at least one of the four sides is straight in the vertical direction.

On the other hand, in the electrode assembly 100, the average distance from the side where the electrode tab 110 is provided to the inner wall of the pouch case 200 is smaller than the average distance between the electrode plate 110 and the pouch case 200 Is formed to be smaller than the average distance to the inner wall of the recess (200). 6, the distance between the electrode plate and the inner wall of the electrode assembly 100 where the electrode tab 110 is not formed is small, and as shown in FIG. 7, It is preferable that the distance between the electrode plate and the inner wall is relatively large. According to this embodiment, the risk of contact between the electrode tab 110 and the electrode plate is lowered, so that the electrode tab 110 and the electrode plate are electrically connected, thereby preventing internal short-circuiting.

The battery pack according to the present invention may include the above-described pouch type secondary battery. In this case, the battery pack may include one or more of the pouch type secondary batteries. In addition to such a secondary battery, the battery pack may include various protection devices for controlling charge and discharge of the secondary battery such as a BMS (Battery Management System) have.

Particularly, the battery pack according to the present invention can be applied to a battery-powered automobile such as an electric car or a hybrid car. That is, the automobile according to the present invention may include the above-described pouch type secondary battery.

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.

100: electrode assembly
110: electrode tab
120: electrode lead
200: Pouch Exterior Material
210: upper pouch
220: Lower pouch

Claims (12)

A pouch exterior member having an upper pouch and an upper pouch, each having an inner space formed therein, and the outer pouch of the upper pouch and the outer pouch of the lower pouch are sealed; And
A plurality of electrode plates housed in an inner space of the pouch exterior material in a stacked manner with a separator sandwiched therebetween, electrode tabs extended from the electrode plate and welded to electrode leads exposed to the outside of the pouch exterior material, The size of the predetermined electrode plate is larger than the size of the other electrode plate,
Lt; / RTI &gt;
Wherein the sealing portion of the upper pouch and the lower pouch are located at a central portion in the vertical direction, and the electrode assembly has the largest electrode plate stacked on the central layer where the sealing portion is located,
Wherein the electrode assembly includes a plurality of electrode tabs having the same polarity,
Wherein a portion of the electrode tabs of the plurality of electrode tabs having the same polarity is attached to the inner wall of the pouch outer case, wherein the center portion of the electrode tabs has a central portion between the flat portions of the upper and lower portions of the pouch outer case and the sealing portion Wherein the pouch type secondary battery is attached to a wall surface of an inclined portion of the pouch type secondary battery.
delete delete The method according to claim 1,
Wherein the electrode assembly gradually increases in size from the outer layer toward the center layer. The method according to claim 1,
Wherein the electrode tab includes an insulating member on at least a part of an inner surface facing the electrode plate. 6. The method of claim 5,
Wherein the insulating member is coated on one surface of the electrode tab. delete The method according to claim 1,
Wherein the electrode tab is attached to an inner space wall surface of the pouch exterior material by an adhesive tape. The method according to claim 1,
The pouch exterior member is sealed with four outer peripheral portions,
Wherein the electrode assembly is formed such that an electrode plate larger than the size of the other electrode plate protrudes in all four outer circumferential directions of the pouch outer casing. The method according to claim 1,
Wherein the electrode assembly has an average distance from the side where the electrode tab is provided to the inner wall of the pouch case and is smaller than an average distance from the side where the electrode tab is not provided to the inner wall of the electrode plate and the pouch case. Pouch type secondary battery. A battery pack comprising the pouch-type secondary battery according to any one of claims 1, 4 to 6, and 8 to 10. An automobile comprising the pouch type secondary battery according to any one of claims 1, 4 to 6, and 8 to 10.

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