KR100896134B1 - Battery Having Biased Electrode Terminals in Both Directions and Battery Pack Comprising the Same - Google Patents

Abstract

According to the present invention, in a battery in which a charge-dischargeable electrode assembly is included in a plate-shaped battery case, and the positive electrode terminal and the negative electrode terminal protrude from opposite ends of the battery case, the electrode terminals are biased toward the corners of the respective ends. It is to provide a battery that is located and the central axis of the electrode terminals is not on the same axis, and a battery module comprising such a battery.

In the case of manufacturing a battery module using the battery, the internal resistance is reduced by minimizing the length of the connection member for the electrical connection of the electrode terminals, and ultimately the battery module can be secured enough to be used for other purposes. It has various advantages such as making the size smaller.

Description

Battery having deflected bidirectional electrode terminal and battery module including the same {Battery Having Biased Electrode Terminals in Both Directions and Battery Pack Comprising the Same}

1 is a perspective view of a typical representative pouch type battery;

FIG. 2 is a schematic view of a battery module configured by electrically connecting a plurality of pouch-type batteries of FIG. 1; FIG.

3 is a schematic diagram of a battery according to one embodiment of the present invention;

4 is a schematic view of a battery module according to an embodiment of the present invention in which the batteries of FIG. 3 are configured in a planar array structure;

5 is a schematic view of a battery module according to another embodiment of the present invention in which the batteries of FIG. 3 are configured in a three-dimensional arrangement.

Description of the main symbols in the drawings

100, 101, 102, 103: pouch type battery (unit cell)

110, 111, 112, 113, 120, 121, 122, 123: electrode tab

130: battery body

200, 201: battery module

210, 211: module case

220: bus bar

230, 240: external input / output terminals

The present invention relates to a battery having an electrode terminal at a biased position at both ends and a battery module including the same. More particularly, the electrode assembly capable of charging and discharging is included in a plate-shaped battery case and includes a positive electrode terminal and a negative electrode. In a battery in which terminals protrude from both ends of a battery case, the electrode terminals are biased toward the corners of each end portion, and a plurality of such batteries are electrically connected to a battery in which a central axis of the electrode terminals is not coaxial. One battery module is provided.

Recently, secondary batteries capable of charging and discharging have been widely used as energy sources of wireless mobile devices. Secondary batteries are also attracting attention as a power source for electric vehicles (EVs) and hybrid electric vehicles (HEVs), which are proposed as a way to solve air pollution in conventional gasoline and diesel vehicles that use fossil fuels. .

While small mobile devices use one or three or four battery cells per device, medium and large devices such as automobiles are used for medium and large battery packs electrically connected to a plurality of battery cells due to the need for high output capacity.

Since medium and large battery packs are preferably manufactured in a small size and weight, plate-type battery cells such as rectangular batteries and pouch-type batteries, which can be stacked with high integration and have a small weight to capacity, are mainly used as unit cells of medium and large battery packs. have. In particular, a pouch type battery using an aluminum laminate sheet as an exterior member has attracted much attention in recent years.

In such a plate-shaped battery, the electrode terminals are generally configured to protrude together on the same surface of the battery outer surface, or to have one electrode terminal protrude from the battery outer surface and the battery case itself to serve as another electrode terminal. However, in the former case, since the positive electrode terminal and the negative electrode terminal are located on the same surface, there is a high risk of short circuit during handling or manufacturing of a battery pack. In the latter case, the risk of short circuit is higher, and the process has a disadvantage because most of the battery case must be insulated except for a portion to be used as an electrode terminal.

Therefore, a structure in which electrode terminals are formed to protrude on different surfaces of a battery outer surface has been developed. Among them, there is a battery structure in which electrode terminals are formed at positions facing each other. As one such example, a perspective view of a typical representative pouch-type battery is shown in FIG.

Referring to FIG. 1, the pouch-type battery 10 has a structure in which two electrode leads (electrode terminals 11 and 12) protrude from each other to protrude from an upper end portion and a lower end portion of the battery body 13. The positions of the electrode leads 11 and 12 at each end are positioned not only on the same axis but also at the center of the battery body 13, thereby forming a symmetrical structure as a whole.

The exterior member 14 is composed of two upper and lower units, and both sides 14a and the upper end and the lower end (14a), which are contact portions, are housed in an electrode assembly (not shown) in the accommodating part 15 formed on the inner surface thereof. The battery 10 is made by adhering the 14b, 14c. The exterior member 14 has a laminate structure of a resin layer / metal foil layer / resin layer, and can be bonded by mutually fusion bonding the resin layer by applying heat and pressure to both side surfaces 14a and the upper and lower ends 14b and 14c which are in contact with each other. In some cases, the adhesive may be bonded using an adhesive. Since both side surfaces 14a are in direct contact with the same resin layer of the upper and lower exterior members 14, uniform sealing is possible by melting. On the other hand, since the electrode leads 11 and 12 protrude from the upper end 14b and the lower end 14c, the sealing property is improved in consideration of the thickness of the electrode leads 11 and 12 and the heterogeneity with the material of the exterior member 14. Heat-sealing is carried out in the state which interposed the film-like sealing member 16 between the electrode leads 11 and 12 so that it may be made.

A schematic diagram constituting a battery module by electrically connecting a plurality of such pouch-type batteries 10 is shown in FIG. 2.

Referring to FIG. 2, a plurality of batteries 10, 10a, 10b, and 10c are arranged on the same plane in the module case 21, and are electrically connected to each other by a bus bar 22 so that the battery module ( 20). Since the length of the bus bar 22 is determined by the separation distance between the corresponding electrode terminals 11 and 12a of the two batteries 10 and 10a, the longer the length of the bus bar 22, the higher the internal resistance is. Degrading module performance. Therefore, in order to reduce the resistance due to the connection between the batteries 10, 10a, that is, to reduce the length of the bus bar 22, in some prior art, the width of the electrode terminals 11, 12, 11a, 12a is greatly increased. In addition, an increase in the electrode terminal width relative to the battery width increases the risk of short circuit in the assembly process of the battery module.

In addition, in the battery module of FIG. 2, dead spaces (DS) exist between the electrode terminals 12a and 11b where the bus bar 22 is not located, and the sizes and the electrode terminals of the batteries 10a and 10b are present. Considering the size and position of the fields 12a, 11b, etc., there is a limit to being used for a special purpose. Considering the fact that the need for a battery pack having a more compact structure with the same capacity and output is increasing, a study on the structure of a battery module that can utilize DS is also required.

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

Specifically, an object of the present invention is to provide a battery that can reduce the internal resistance by greatly reducing the length of the connection member for the electrical connection of the electrode terminals in the manufacture of the battery module.

Still another object of the present invention is to provide a battery having a size sufficient to allow a dead space to be used for other purposes when the battery module is manufactured.

Another object of the present invention is to provide a battery module that is more compact and easy to assemble by including such batteries as a unit cell.

In the battery according to the present invention for achieving the above object, the battery assembly includes an electrode assembly capable of charging and discharging in a plate-shaped battery case, the positive electrode terminal and the negative electrode terminal protrudes opposite to both ends of the battery case, The electrode terminals are positioned to be biased toward the corners of each end and are characterized in that the central axis of the electrode terminals is not on the same axis.

Therefore, the battery according to the present invention has a structure in which the positive electrode terminal and the negative electrode terminal protrude from each other at opposite ends on the long axis or short axis of the battery, and these electrode terminals are disposed to be deflected from each other. In this case, the internal resistance can be greatly reduced by reducing the length of the connection member for the electrical connection between the terminals, and the dead space (DS) inside the battery module can be secured to a size sufficient for other purposes. Has

Since the battery according to the present invention is a thin battery having a thin thickness as a whole, a square battery, a pouch battery, and the like may be possible. The battery case is preferably composed of a laminate structure of a metal layer and a resin layer, and a representative example of such a battery includes a pouch type battery in which the battery case is made of a laminate sheet of aluminum and resin. In the pouch-type battery, the battery case may have various structures. For example, the battery case may be a folding unit of one unit, and the upper and / or lower contact portions may be stored after receiving the electrode assembly in the upper and / or lower inner surfaces. Sealing structure; The structure of sealing an upper and lower contact part after accommodating an electrode assembly in the accommodating part formed in the upper and / or lower inner surface as a member of 2 units is mentioned. A pouch-type battery having such a structure is disclosed in PCT International Application No. PCT / KR2004 / 003312 to the applicant, which is incorporated by reference in the context of the present invention.

The electrode assembly is composed of a positive electrode and a negative electrode to enable charge and discharge, for example, a structure in which the positive electrode and the negative electrode are laminated with a separator interposed therebetween, a jelly-roll method or a stacked type. The positive electrode and the negative electrode of the electrode assembly may form an electrode terminal by protruding the electrode tab thereof directly to the outside of the battery, or the electrode tab may be connected to a separate lead to protrude out of the battery to constitute the electrode terminal. It may be.

In one preferred example, the electrode terminals are located at both ends on the long axis of the cell. When the electrode terminals are positioned at both ends on the long axis of the battery and have a structure that can be bent like electrode tabs or electrode leads, depending on the arrangement of the battery module, the electrode tabs or electrode leads may be mutually separated without using a connection member. It may also be possible to connect directly.

As described above, one of the features of the present invention is that each electrode terminal is biased toward the edge of the end, and another feature is that the central axes of the electrode terminals are not coaxial with each other. In the above, "the electrode terminal is biased toward the edge of the end" means that the vertical center axis of the electrode terminal is spaced apart from the center axis of the battery.

In one preferred example, the electrode terminals protruding on both ends may be located at a point symmetrical with respect to the center point of the battery. As such an example, there is a structure in which the electrode terminal of the upper end is deflected to the left and the electrode terminal of the lower part is deflected to the right by the same distance as described above.

The degree of deflection of the electrode terminal may vary according to various conditions, and as an example, the electrode terminal may have a structure in which the electrode terminal is deflected to a degree completely deviating from the central axis of the battery body.

The width of the electrode terminal is not particularly limited, but may preferably be 1/2 or less, more preferably 2/5 or less, of the battery body. For example, when the width of the electrode terminal is 2/5 or less of the width of the battery body and the electrode terminal is deflected to be completely out of the central axis of the battery body, when configuring a battery module by arranging a plurality of batteries, Sufficient dead space DS can be obtained to the extent that it can be used.

The present invention also provides a battery module including a plurality of such cells as a unit cell. In such a battery module, the unit cells are arranged such that electrode terminals adjacent to each other are positioned at the shortest distance, and are electrically connected by a connection member such as a bus bar.

Connection of the electrode terminal and the connecting member can be generally achieved by welding, soldering, mechanical fastening, etc., but is not particularly limited.

The arrangement of unit cells in the battery module may vary, for example, a planar array structure (N × 1) in which two or more unit cells are arranged in a row on a plane, and two or more units arranged in a plane A stereo array structure (N × n) in which cells are stacked in two rows or more may be possible. Details of the three-dimensionally arranged structure are disclosed in Korean Patent Application No. 2005-51657 to the applicant, which is incorporated by reference in the context of the present invention.

Such a battery module may be configured as a battery pack as it is, and in some cases, a medium-large battery pack may be configured by electrically connecting a plurality of battery modules.

Such medium and large battery packs may be preferably used in devices such as electric vehicles (EVs), hybrid electric vehicles (HEVs), electric motorcycles, electric bicycles, and the like, which require high output and large capacity.

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

3 schematically illustrates a battery according to one embodiment of the present invention. Since the battery of FIG. 3 is the same as the battery of FIG. 1 in the basic configuration of the battery and there is a difference in the position of the electrode tab, only the battery body and the electrode tab are shown in the drawings without any other specific configuration (structure).

Referring to FIG. 3, two electrode tabs 110 and 120 protrude from the top and bottom of the battery body 130 in the long axis direction of the battery body 130, respectively. In addition, the electrode tabs 110 and 120 have their vertical center axes Xa and Xb, respectively, spaced apart from the center axis Xc of the battery body 130 and are deflected toward the edges of the end portions of FIG. 1. Compared with the electrode tabs 11 and 12, the structure is generally asymmetrical. On the other hand, the deflected electrode tabs 110 and 120 exhibit a symmetrical arrangement when the center C of the battery body 130 is referred to. In addition, the width w of the electrode tab 110 is 1/2 or less of the width W of the battery body, and the inner end 112 is deflected in a state completely separated from the battery body filling shaft Xc.

When the battery body 130 is asymmetrical in thickness, it is easier to distinguish between the positive electrode and the negative electrode due to the deflecting structure of the electrode tabs 110 and 120, so that a worker may accidentally handle the battery 100. There are also benefits that can greatly reduce the risk of short circuits.

Figure 4 is a schematic diagram of a battery module according to an embodiment of the present invention composed of the battery of Figure 3 is shown.

Referring to FIG. 4, in the battery module 200, four unit cells 100, 101, 102, and 103 are planarly arranged side by side in the module case 210. The unit cells 100, 101, 102, and 103 are electrically connected to each other by a bus bar 220, which is a connection member, with electrode tabs arranged adjacent to each other. For example, the negative electrode tab 120 of the first unit cell 100 that is biased toward the right end corner may have a bus bar at a short distance from the positive electrode tab 111 of the second unit cell 101 that is biased toward the left end corner. Electrical connection by 220. On the contrary, the negative electrode tab 121 of the second unit cell 101 that is biased toward the left end corner is connected to the positive electrode tab 112 of the third unit cell 102 that is biased toward the right end corner and the bus bar 220 is located at a short distance. Is electrically connected by Accordingly, when the size of the battery and the electrode tab is the same, the bus bar 220 of FIG. 4 may make an electrical connection even with a shorter length than the bus bar 22 of FIG. 2, thereby reducing the internal resistance. .

In addition, due to the deflected position of the electrode tabs and the unique arrangement of the unit cells, the size of the dead space DS in which the electrode tabs 110, 120, 111, 121... 2, the dead space DS is used as a coolant flow path when the battery pack is configured, or the battery module 200 is mounted in the battery pack housing (not shown). It can also be used as an installation space for fastening members for many advantages.

5 is a schematic view of a battery module according to another embodiment of the present invention constituted of the batteries of FIG.

Referring to FIG. 5, the battery module 201 is composed of two unit cell rows, and each unit cell has a 2 × 2 stereoscopic structure in which two unit cells 100, 110, 120, and 130 are arranged. It has a structural arrangement.

First, in the unit cells 100 and 103 of the first row, the positive electrode tab 110 and the negative electrode tab 123 are electrically connected to the external input / output terminals 230 and 240 through the bus bar 220, respectively. The external input / output terminals 230 and 240 may be directly connected to a battery management system (BMS) of a battery pack (not shown), or may be connected to another battery module (not shown). In the unit cells 101 and 102 of the second row, the electrode tabs 121 and 112 are electrically connected to each other at a short distance by the bus bar 220 as shown in FIG. 4. Since the unit cells 100 and 103 in the first row and the unit cells 101 and 102 in the second row face each other on a plane, the electrode tabs are very close to each other. Therefore, the negative electrode tab 120 of the first unit cell 100 and the positive electrode tab 111 of the second unit cell 101 may be bent to face each other, such that direct welding, soldering, and mechanical fastening may be performed. Similarly, the negative electrode tab 122 of the third unit cell 102 and the positive electrode tab 113 of the fourth unit cell 103 may also be bent to face each other to perform direct welding, soldering, or mechanical fastening.

Since the battery module 201 of FIG. 5 has a predetermined length not only in the row direction (horizontal direction) but also in the column direction (vertical direction), the mechanical rigidity of the battery module case 211 is further excellent, and the required bus bar ( The number of 220 can be minimized. In addition, since the dead space DSb at the bottom of the battery module becomes larger in the vertical direction, the utilization rate increases. Since the dead space DSa having a constant size in the vertical direction is formed on the top of the battery module, the structure of the external input / output terminals 230 and 240 may be manufactured in an arbitrary shape within an acceptable range.

While certain embodiments have been described with reference to the drawings, those skilled in the art to which the present invention pertains will be able to perform various applications and modifications within the scope of the present invention based on the above contents.

As described above, in the battery according to the present invention, since the electrode terminals are biased under specific conditions, when configuring a battery module by arranging a plurality of batteries in various ways, the length of the connection member for the electrical connection of the electrode terminals is minimized. By reducing the internal resistance, the size of the dead space can be secured enough to be used for other purposes, and ultimately, the size of the battery module can be made smaller. Such a battery module may be preferably used in medium and large battery packs that are power sources of electric vehicles, hybrid electric vehicles, electric motorcycles, electric bicycles, and the like.

Claims (11)

An electrode assembly capable of charging and discharging is included in a plate-shaped battery case, and includes a plurality of cells in which a cathode terminal and a cathode terminal protrude from opposite ends of the battery case as unit cells, and the unit cells are adjacent to each other. Battery modules are arranged so that they are located at the shortest distance, In the battery, the electrode terminals are biased toward the edges of both ends on the long axis of the battery, and the central axis of the electrode terminals is not on the same axis. The battery module has a planar array structure in which two or more unit cells are arranged in one row on a plane (N x 1), or two or more unit cells arranged in a plane on a condition that a dead space is maximized. And a three-dimensional array structure (N xn) stacked in rows or more, wherein the unit cells of the planar array are electrically connected by a connection member. The battery module according to claim 1, wherein the battery is a pouch type battery in which a battery case is formed of a laminate structure of a metal layer and a resin layer. The battery case of claim 2, wherein the battery case is a folding unit of one unit, and has a structure for sealing the upper and lower contact portions after receiving the electrode assembly in the accommodating portion formed on the upper and / or lower inner surfaces; Or a battery module having a structure of sealing the upper and lower contact portions after accommodating the electrode assembly in an accommodating portion formed on the upper and / or lower inner surfaces as a member of two units. delete The battery module according to claim 1, wherein the electrode terminal is an electrode tab or an electrode lead. The battery module according to claim 1, wherein the electrode terminals are biased on both ends at positions symmetrical with respect to the center point of the battery. The battery module according to claim 1, wherein the electrode terminal is deflected to a degree completely deviating from the central axis of the battery body. The method of claim 1, wherein the width of the electrode terminal is a battery module, characterized in that less than 1/2 of the width of the battery body. delete delete The battery module according to claim 1, wherein the battery module is used as a power source of an electric vehicle (EV), a hybrid electric vehicle (HEV), an electric motorcycle, or an electric bicycle.

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