Long width secondary battery

In the present invention, not only a movement path of a current generated from a first electrode assembly, but also a movement path of a current generated from a second electrode assembly are provided by a cathode conductive member, and not only a movement path of the current generated from the second electrode assembly, but also a movement path of the current generated from the first electrode assembly are provided by an anode conductive member, such that cross sectional areas of the correct movement paths are increased. Therefore, a resistance of the long width secondary battery may be reduced.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2019-0066011, filed on Jun. 4, 2019, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

The following disclosure relates to a long width secondary battery in which current movement paths are additionally provided in order to reduce a resistance thereof.

BACKGROUND

A battery may be classified into a primary battery and a secondary battery. The primary battery refers to a battery which cannot be reused after it is used one time, because the primary battery produces electricity using an irreversible reaction. Examples of the primary battery include a dry battery, a mercury battery, and a voltaic battery. On the other hand, the secondary battery refers to a battery which can be reused after use, because the secondary cell battery is recharged by a reversible reaction. Examples of the secondary battery include a lead storage battery, a lithium ion battery, and a Ni—Cd battery.

The secondary battery may be classified into a stacked-type secondary battery and a wound-type secondary battery depending on the forms of a cathode plate, an anode plate, and a separator. Here, in the case of the stacked-type secondary battery, the longer the lateral widths of a cathode plate and an anode plate, the longer the current movement path during charge and discharge, and the longer the current movement path, the greater the resistance of the stacked-type secondary battery.

A stacked-type secondary battery having relatively long widths of a cathode plate and an anode plate (that is, long width secondary battery) may be used in an electric vehicle or a hybrid vehicle. In the case of the long width secondary battery used in the electric vehicle or the hybrid vehicle, the lower the resistance, the higher the electrical output. However, the long width secondary battery has a relatively high resistance due to the long widths of the cathode plate and the anode plate. Accordingly, a large amount of loss in electrical output generated from the long width secondary battery may occur.

RELATED ART DOCUMENT

Patent Document 1

SUMMARY

An embodiment of the present invention is directed to providing a long width secondary battery of which a resistance may be reduced and a loss in electrical output may thus be reduced.

Another embodiment of the present invention is directed to providing a long width secondary battery of which a strength and an assembly efficiency may be improved.

In one aspect, a long width secondary battery includes: a first electrode assembly including a plurality of first cathode plates corresponding to portions of first cathode current collectors where a cathode active material is coated, a plurality of first anode plates corresponding to portions of first anode current collectors where an anode active material is coated, and a first separator disposed between each of the first cathode plates and each of the first anode plates; and a second electrode assembly including a plurality of second cathode plates corresponding to portions of second cathode current collectors where a cathode active material is coated, a plurality of second anode plates corresponding to portions of second anode current collectors where an anode active material is coated, and a second separator disposed between each of the second cathode plates and each of the second anode plates, wherein the first cathode plate has a first cathode uncoated portion that corresponds to a portion of the first cathode current collector where the cathode active material is not coated and is positioned on a first side of the first electrode assembly, and the first anode plate has a first anode uncoated portion that corresponds to a portion of the first anode current collector where the anode active material is not coated and is positioned on the first side of the first electrode assembly, the second cathode plate has a second cathode uncoated portion that corresponds to a portion of the second cathode current collector where the cathode active material is not coated, is positioned on a second side of the second electrode assembly, and is connected to the first cathode uncoated portion, and the second anode plate has a second anode uncoated portion that corresponds to a portion of the second anode current collector where the anode active material is not coated, is positioned on the second side of the second electrode assembly, and is connected to the first anode uncoated portion, and the first cathode uncoated portion and the second cathode uncoated portion are connected to a cathode tab positioned on a second side of the first electrode assembly by a cathode conductive member, and the first anode uncoated portion and the second anode uncoated portion are connected to an anode tab positioned on a first side of the second electrode assembly by an anode conductive member.

The first electrode assembly and the second electrode assembly may be disposed in a state in which the first side of the first electrode assembly and the second side of the second electrode assembly face each other, the cathode tab may be provided on the second side of the first electrode assembly, and the anode tab may be provided on the first side of the second electrode assembly.

The cathode conductive member and the anode conductive member may be formed in a plate shape.

A thickness of the cathode conductive member may be larger than those of the first cathode current collector and the second cathode current collector, and a thickness of the anode conductive member may be larger than those of the first anode current collector and the second anode current collector.

The cathode conductive member and the anode conductive member may be formed in an electric wire shape.

The first cathode current collector, the second cathode current collector, and the cathode conductive member may be formed of the same materials, and the first anode current collector, the second anode current collector, and the anode conductive member may be formed of the same materials.

The long width secondary battery may further include a support member supporting the first electrode assembly and the second electrode assembly, wherein the cathode conductive member and the anode conductive member may be provided on the support member.

A step may be provided on the support member, the first electrode assembly may be disposed on one side of the support member based on the step, and the second electrode assembly may be disposed on the other side of the support member based on the step, and the first cathode uncoated portion and the second cathode uncoated portion may be connected to the cathode conductive member at the step, and the first anode uncoated portion and the second anode uncoated portion may be connected to the anode conductive member at the step.

In another general aspect, a long width secondary battery includes: a first electrode assembly including a plurality of first cathode plates corresponding to portions of first cathode current collectors where a cathode active material is coated, a plurality of first anode plates corresponding to portions of first anode current collectors where an anode active material is coated, and a first separator disposed between each of the first cathode plates and each of the first anode plates; a second electrode assembly including a plurality of second cathode plates corresponding to portions of second cathode current collectors where a cathode active material is coated, a plurality of second anode plates corresponding to portions of second anode current collectors where an anode active material is coated, and a second separator disposed between each of the second cathode plates and each of the second anode plates; and a third electrode assembly including a plurality of third cathode plates corresponding to portions of third cathode current collectors where a cathode active material is coated, a plurality of third anode plates corresponding to portions of third anode current collectors where an anode active material is coated, and a third separator disposed between each of the third cathode plates and each of the third anode plates, and disposed between the first electrode assembly and the second electrode assembly, wherein the first cathode plate has a first cathode uncoated portion that corresponds to a portion of the first cathode current collector where the cathode active material is not coated and is positioned on a first side of the first electrode assembly, and the first anode plate has a first anode uncoated portion that corresponds to a portion of the first anode current collector where the anode active material is not coated and is positioned on the first side of the first electrode assembly, the second cathode plate has a second cathode uncoated portion that corresponds to a portion of the second cathode current collector where the cathode active material is not coated and is positioned on a second side of the second electrode assembly, and the second anode plate has a second anode uncoated portion that corresponds to a portion of the second anode current collector where the anode active material is not coated and is positioned on the second side of the second electrode assembly, the third cathode plate has a third cathode uncoated portion that corresponds to a portion of the third cathode current collector where the cathode active material is not coated, is positioned on a second side of the third electrode assembly, and is connected to the first cathode uncoated portion, and a fourth cathode uncoated portion that is positioned on a first side of the third electrode assembly and is connected to the second cathode uncoated portion, the third anode plate has a third anode uncoated portion that corresponds to a portion of the third anode current collector where the anode active material is not coated, is positioned on the second side of the third electrode assembly, and is connected to the first anode uncoated portion, and a fourth anode uncoated portion that is positioned on the first side of the third electrode assembly and is connected to the second anode uncoated portion, the first cathode uncoated portion and the third cathode uncoated portion are connected to a cathode tab positioned on a second side of the first electrode assembly by a first cathode conductive member, and the second cathode uncoated portion and the fourth cathode uncoated portion are connected to the first cathode uncoated portion and the third cathode uncoated portion by a second cathode conducive member, and the second anode uncoated portion and the fourth anode uncoated portion are connected to an anode tab positioned on a first side of the second electrode assembly by a first anode conductive member, and the first anode uncoated portion and the third anode uncoated portion are connected to the second anode uncoated portion and the fourth anode uncoated portion by a second anode conductive member.

The first electrode assembly and the third electrode assembly may be disposed in a state in which the first side of the first electrode assembly and the second side of the third electrode assembly face each other, the second electrode assembly and the third electrode assembly may be disposed in a state in which the second side of the second electrode assembly and the first side of the third electrode assembly face each other, the cathode tab may be provided on the second side of the first electrode assembly, and the anode tab may be provided on the first side of the second electrode assembly.

The first cathode conductive member, the second cathode conductive member, the first anode conductive member, and the second anode conductive member may be formed in a plate shape.

Thicknesses of the first cathode conductive member and the second cathode conductive member may be larger than those of the first cathode current collector, the second cathode current collector, and the third cathode current collector, and thicknesses of the first anode conductive member and the second anode conductive member may be larger than those of the first anode current collector, the second anode current collector, and the third anode current collector.

The first cathode conductive member, the second cathode conductive member, the first anode conductive member, and the second anode conductive member may be formed in an electric wire shape.

The first cathode current collector, the second cathode current collector, the third cathode current collector, the first cathode conductive member, and the second cathode conductive member may be formed of the same materials, and the first anode current collector, the second anode current collector, the third anode current collector, the first anode conductive member, and the second anode conductive member may be formed of the same materials.

The long width secondary battery may further include a support member supporting the first electrode assembly, the second electrode assembly, and the third electrode assembly, wherein the first cathode conductive member, the second cathode conductive member, the first anode conductive member, and the second anode conductive member may be provided on the support member.

A plurality of steps may be provided on the support member, the first electrode assembly may be disposed on one side of the support member based on one of the plurality of steps, the second electrode assembly may be disposed on the other side of the support member based on the other one of the plurality of steps, and the third electrode assembly may be disposed between the plurality of steps, the first cathode uncoated portion and the third cathode uncoated portion may be connected to the first cathode conductive member and the second cathode conductive member at one of the plurality of steps, and the second cathode uncoated portion and the fourth cathode uncoated portion may be connected to the second cathode conductive member at the other one of the plurality of steps, and the second anode uncoated portion and the fourth anode uncoated portion may be connected to the first anode conductive member and the second anode conductive member at one of the plurality of steps, and the first anode uncoated portion and the third anode uncoated portion may be connected to the second anode conductive member at the other one of the plurality of steps.

DETAILED DESCRIPTION OF MAIN ELEMENTS

100: First electrode assembly

110: First cathode plate

115: First cathode current collector

117: First cathode uncoated portion

120: First anode plate

125: First anode current collector

127: First anode uncoated portion

200: Second electrode assembly

210: Second cathode plate

215: Second cathode current collector

217: Second cathode uncoated portion

220: Second anode plate

225: Second anode current collector

227: Second anode uncoated portion

300: Third electrode assembly

310: Third cathode plate

315: Third cathode current collector

317: Third cathode uncoated portion

320: Third anode plate

325: Third anode current collector

327-1: Third anode uncoated portion

327-2: Fourth anode uncoated portion

400: Cathode conductive member

500: Anode conductive member

600: Support member

DETAILED DESCRIPTION OF EMBODIMENTS

Hereinafter, a long width secondary battery according to the present invention will be described in detail with reference to the accompanying drawings. The accompanying drawings are provided by way of example in order to sufficiently transfer the spirit of the present invention to those skilled in the art, and the present invention is not limited to the accompanying drawings provided below, but may be implemented in other forms.

FIG.1is a front perspective view of a long width secondary battery according to a first exemplary embodiment of the present invention. As illustrated inFIG.1, the long width secondary battery according to the first exemplary embodiment of the present invention includes a first electrode assembly100, a second electrode assembly200, a cathode conductive member400, and an anode conductive member500.

The first electrode assembly100and the second electrode assembly200may be short width secondary batteries. The first electrode assembly100and the second electrode assembly200may be disposed in a state in which a first side of the first electrode assembly100and a second side of the second electrode assembly200face each other. Therefore, a long width secondary battery may be formed. A cathode tab130may be provided on a second side of the first electrode assembly100, and an anode tab230may be provided on a first side of the second electrode assembly200.

The first electrode assembly100includes a plurality of first cathode plates110corresponding to portions of first cathode current collectors115where a cathode active material is coated, a plurality of first anode plates120corresponding to portions of first anode current collectors125where an anode active material is coated, and a first separator (not illustrated) disposed between each of the first cathode plates110and each of the first anode plates120. Here, the first cathode current collector115may be an aluminum foil, and the first anode current collector125may be a copper foil. The portion of the first cathode current collector115where the cathode active material is coated (first cathode coated portion) and the portion of the first anode current collector125where the anode active material is coated (first anode coated portion) are chemically reacted each other to generate a current.

The first cathode plate110has a first cathode uncoated portion117that corresponds to the portion of the first cathode current collector115where the cathode active material is not coated, and is positioned on the first side of the first electrode assembly100. A plurality of first cathode uncoated portions117are welded to each other and are connected to a plurality of second cathode uncoated portions217.

The first anode plate120has a first anode uncoated portion127that corresponds to the portion of the first anode current collector125where the anode active material is not coated, and is positioned on the first side of the first electrode assembly100. A plurality of first anode uncoated portions127are welded to each other and are connected to a plurality of second anode uncoated portions227.

The second electrode assembly200includes a plurality of second cathode plates210corresponding to portions of second cathode current collectors215where a cathode active material is coated, a plurality of second anode plates220corresponding to portions of second anode current collectors225where an anode active material is coated, and a second separator (not illustrated) disposed between each of the second cathode plates210and each of the second anode plates220. Here, the second cathode current collector215may be an aluminum foil, and the second anode current collector225may be a copper foil. The portion of the second cathode current collector215where the cathode active material is coated (second cathode coated portion) and the portion of the second anode current collector225where the anode active material is coated (second anode coated portion) are chemically reacted to each other to generate a current.

The second cathode plate210has the second cathode uncoated portion217that corresponds to the portion of the second cathode current collector215where the cathode active material is not coated, and is positioned on the second side of the second electrode assembly200. The plurality of second cathode uncoated portions217are welded to each other and are connected to the plurality of first cathode uncoated portions117. Here, the plurality of first cathode uncoated portions117and the plurality of second cathode uncoated portions217may also be connected to each other by welding.

In addition, the first cathode uncoated portion117and the second cathode uncoated portion217are connected to the cathode tab130positioned on the second side of the first electrode assembly100by the cathode conductive member400. That is, one end of the cathode conductive member400that is positioned on a first side of the cathode conductive member400is connected to the first cathode uncoated portion117and the second cathode uncoated portion217, and the other end of the cathode conductive member400that is positioned on a second side of the cathode conductive member400is connected to the cathode tab130. The cathode conductive member400not only connects the first cathode uncoated portion117to the cathode tab130to provide a movement path of a current generated from the first electrode assembly100, but also connects the second cathode uncoated portion217to the cathode tab130to provide a movement path of a current generated from the second electrode assembly200. The cathode conductive member400and the cathode uncoated portions117and217, and the cathode conductive member400and the cathode tab130may be connected to each other by welding, respectively.

The second anode plate220has the second anode uncoated portion227that corresponds to the portion of the second anode current collector225where the anode active material is not coated, and is positioned on the second side of the second electrode assembly200. The plurality of second anode uncoated portions227are welded to each other and are connected to the plurality of first anode uncoated portions127. Here, the plurality of first anode uncoated portions127and the plurality of second anode uncoated portions227may also be connected to each other by welding.

In addition, the first cathode uncoated portion127and the second cathode uncoated portion227are connected to the anode tab230positioned on the first side of the second electrode assembly200by the anode conductive member500. That is, one end of the anode conductive member500that is positioned on a first side of the anode conductive member500is connected to the anode tab230, and the other end of the anode conductive member500that is positioned on a second side of the anode conductive member500is connected to the first anode uncoated portion127and the second anode uncoated portion227. The anode conductive member500not only connects the second anode uncoated portion227to the anode tab230to provide a movement path of the current generated from the second electrode assembly200, but also connects the first anode uncoated portion127to the anode tab230to provide a movement path of the current generated from the first electrode assembly100. The anode conductive member500and the anode uncoated portions127and227, and the anode conductive member500and the anode tab230may be connected to each other by welding, respectively.

As such, in the case where not only the movement path of the current generated from the first electrode assembly100, but also the movement path of the current generated from the second electrode assembly200are provided by the cathode conducive member400, and not only the movement path of the current generated from the second electrode assembly200, but also the movement path of the current generated from the first electrode assembly100are provided by the anode conductive member500, cross sectional areas of the current movement paths are increased, and a resistance of the long width secondary battery is thus reduced.

The cathode conductive member400and the anode conductive member500may be formed in a plate shape. The conductive member formed in a plate shape allows the cross sectional areas of the current movement paths to be increased, and the resistance of the long width secondary battery is easily reduced.

As illustrated inFIG.1, the cathode conductive member400may provide the current movement path at a lower portion of the first electrode assembly100, and the anode conductive member500may provide the current movement path at a lower portion of the second electrode assembly200. However, the cathode conductive member400may provide the current movement path at an upper portion or one side surface portion of the first electrode assembly100, and the anode conductive member500may provide the current movement path at an upper portion or one side surface portion of the second electrode assembly200.

Thicknesses of the cathode conductive member400and the anode conductive member500are closely related to the cross sectional areas of the current movement paths. That is, the cross sectional area of the current movement path may be increased in proportion to the thickness of each of the cathode conductive member400and the anode conductive member500. As a result, the resistance of the long width secondary battery may be reduced. However, since thicknesses of the cathode current collectors115and215and the anode current collectors125and225are also related to the cross sectional areas of the current movement paths, in order to greatly reduce the resistance of the long width secondary battery, it is preferable that the thickness of the cathode conductive member400is larger than those of the cathode current collectors115and215, and the thickness of the anode conductive member500is larger than those of the anode current collectors125and225.

The cathode conductive member400and the anode conductive member500formed only in a plate shape are illustrated inFIG.1, but the cathode conductive member400and the anode conductive member500may be formed in an electric wire shape having a width narrower than that of the place shape. Since the electric wire shape has a cross sectional area smaller than that of the plate shape, the electric wire shape has a low degree of contribution to reduction in resistance of the long width secondary battery, but may allow the production of a small and lightweight long width secondary. Moreover, the cathode conductive member400and the anode conductive member500formed in an electric wire shape have a high energy density, and thus the long width secondary battery may provide a relatively high electrical output.

As described above, one end of the cathode conductive member400that is positioned on the first side of the cathode conductive member400is connected to the first cathode uncoated portion117and the second cathode uncoated portion217, and one end of the anode conductive member500that is positioned on the second side of the anode conductive member500is connected to the first anode uncoated portion127and the second anode uncoated portion227. In this case, in general, the conductive member and the uncoated portion are connected to each other by ultrasonic welding. When the conductive member and the uncoated portion are formed of the same materials, the ultrasonic welding may be further smoothly performed. Therefore, it is preferable that the first cathode current collector115, the second cathode current collector215, and the cathode conductive member400are formed of the same materials, and the first anode current collector125, the second anode current collector225, and the anode conductive member500are formed of the same materials. For example, when the cathode current collectors115and215are formed of an aluminum material, it is preferable that the cathode conductive member400is also formed of the aluminum material. When the anode current collectors125and225are formed of a copper material, it is preferable that the anode conductive member500is also formed of the copper material.

FIG.2Ais a front view of the support member supporting the electrode assembly ofFIG.1, andFIG.2Bis a rear view of the support member supporting the electrode assembly of theFIG.1.FIG.3is a plan view of the support member supporting the electrode assembly ofFIG.1, andFIG.4is a view illustrating a state in which the electrode assembly ofFIG.1is mounted on the support member.

As illustrated inFIGS.2A to4, the long width secondary battery according to the first exemplary embodiment of the present invention may further include a support member600supporting the first electrode assembly100and the second electrode assembly200. The support member600is disposed at the lower portions of the electrode assemblies100and200and supports the electrode assemblies100and200, such that the support member600may contribute to improving a strength of the long width secondary battery.

In addition, the cathode conductive member400and the anode conductive member500may be provided on the support member600. More specifically, a step650is provided at an approximately central portion of the support member600. The cathode conductive member400extends from the step650toward one side of the support member600. The anode conductive member500extends from the step650toward the other side of the support member600.

In this case, the cathode conductive member400may be provided at a position corresponding to the first cathode uncoated portion117and the second cathode uncoated portion217, for example, a portion biased forward of the support member600, in order to connect the first cathode uncoated portion117and the second cathode uncoated portion217. In addition, the anode conductive member500may be provided at a position corresponding to the first anode uncoated portion127and the second anode uncoated portion227, for example, a portion biased rearward of the support member600, in order to connect the first anode uncoated portion127and the second anode uncoated portion227.

The first electrode assembly100may be disposed on one side of the support member600based on the step650, and the second electrode assembly200may be disposed on the other side of the support member600based on the step650. In addition, the first cathode uncoated portion317and the second cathode uncoated portion217may be connected to each other at the step650by welding with the cathode conductive member400. The first anode uncoated portion127and the second anode uncoated portion227may be connected to each other at the step650by welding with the anode conductive member500.

As such, the electrode assemblies100and200are disposed on the support member600provided with the step650, the cathode uncoated portions117and217are connected to the cathode conductive member400at the step650, and the anode uncoated portions127and227are connected to the anode conductive member500at the step650, such that a strength and an assembly efficiency of the long width secondary battery may be increased.

Meanwhile,FIG.5is a front perspective view of a long width secondary battery according to a second exemplary embodiment of the present invention. As illustrated inFIG.5, the long width secondary battery according to the second exemplary embodiment of the present invention includes a first electrode assembly100, a second electrode assembly200, a third electrode assembly300, a first cathode conductive member410, a second cathode conductive member420, a first anode conductive member510, and a second anode conductive member520. The second exemplary embodiment of the present invention is different from the first exemplary embodiment in that the third electrode assembly300is disposed between the first electrode assembly100and the second electrode assembly200, and a plurality of cathode conductive members410and420and a plurality of anode conductive members510and520are included. Hereinafter, the second exemplary embodiment will be described, focusing on the differences from the first exemplary embodiment.

The third electrode assembly300may be a short width secondary battery. The first electrode assembly100and the third electrode assembly300may be disposed in a state in which a first side of the first electrode assembly100and a second side of the third electrode assembly300face each other, and the second electrode assembly200and the third electrode assembly300may be disposed in a state in which a second side of the second electrode assembly200and a first side of the third electrode assembly300face each other. Therefore, a long width secondary battery may be formed. A cathode tab130may be provided on a second side of the first electrode assembly100, and an anode tab230may be provided on a first side of the second electrode assembly200.

The third electrode assembly300includes a plurality of third cathode plates310corresponding to portions of third cathode current collectors315where a cathode active material is coated, a plurality of third anode plates320corresponding to portions of third anode current collectors325where an anode active material is coated, and a third separator (not illustrated) disposed between each of the third cathode plates310and each of the third anode plates320. Here, the third cathode current collector315may be an aluminum foil, and the third anode current collector325may be a copper foil. The portion of the third cathode current collector315where the cathode active material is coated (third cathode coated portion) and the portion of the third anode current collector325where the anode active material is coated (third anode coated portion) are chemically reacted to each other to generate a current.

The third cathode plate310has a third cathode uncoated portion317-1and a fourth cathode uncoated portion317-2that correspond to the portion of the third cathode current collector315where the cathode active material is not coated, the third cathode uncoated portion317-1being positioned on the second side of the third electrode assembly300and connected to a first cathode uncoated portion117of the first electrode assembly100, and the fourth cathode uncoated portion317-2being positioned on the first side of the third electrode assembly300and connected to a second cathode uncoated portion217of the second electrode assembly200. That is, a plurality of third cathode uncoated portions317-1are welded to each other and are connected to the plurality of first cathode uncoated portions117. A plurality of fourth cathode uncoated portions317-2are welded to each other and are connected to the plurality of second cathode uncoated portions217. Here, the plurality of first cathode uncoated portions117and the plurality of third cathode uncoated portions317-1may also be connected to each other by welding, and the plurality of second cathode uncoated portions217and the plurality of fourth cathode uncoated portions317-2may also be connected to each other by welding.

In addition, the first cathode uncoated portion117and the third cathode uncoated portion317-1are connected to the cathode tab130positioned on the second side of the first electrode assembly100by the first cathode conductive member410. That is, one end of the first cathode conductive member410that is positioned on a first side of the first cathode conductive member410is connected to the first cathode uncoated portion117and the third cathode uncoated portion317-1, and the other end of the first cathode conductive member410that is positioned on a second side of the first cathode conductive member410is connected to the cathode tab130. The first cathode conductive member410not only connects the first cathode uncoated portion117to the cathode tab130to provide a movement path of a current generated from the first electrode assembly100, but also connects the third cathode uncoated portion317-1to the cathode tab130to provide a movement path of a current generated from the third electrode assembly300. The first cathode conductive member410and the cathode uncoated portions117and317-1, and the first cathode conductive member410and the cathode tab130may be connected to each other by welding, respectively.

In addition, the second cathode uncoated portion217and the fourth cathode uncoated portion317-2are connected to the first cathode uncoated portion117and the third cathode uncoated portion317-1by the second cathode conductive member420. That is, one end of the second cathode conductive member420that is positioned on a first side of the second cathode conductive member420is connected to the second cathode uncoated portion217and the fourth cathode uncoated portion317-2, and the other end of the second cathode conductive member420that is positioned on a second side of the second cathode conductive member420is connected to the first cathode uncoated portion117and the third cathode uncoated portion317-1. The second cathode conductive member420not only connects the fourth cathode uncoated portion317-2to the first cathode uncoated portion117and the third cathode uncoated portion317-1to provide a movement path of the current generated from the third electrode assembly300, but also connects the second cathode uncoated portion217to the first cathode uncoated portion117and the third cathode uncoated portion317-1to provide a movement path of a current generated from the second electrode assembly200. The second cathode conductive member420and the cathode uncoated portions217and317-2, and the second cathode conductive member420and the cathode uncoated portions117and317-1may be connected to each other by welding, respectively.

The third anode plate320has a third anode uncoated portion327-1and a fourth anode uncoated portion327-2that correspond to the portion of the third anode current collector325where the anode active material is not coated, the third anode uncoated portion327-1being positioned on the second side of the third electrode assembly300and connected to a first anode uncoated portion127of the first electrode assembly100, and the fourth anode uncoated portion327-2being positioned on the first side of the third electrode assembly300and connected to a second anode uncoated portion227of the second electrode assembly200. That is, a plurality of third anode uncoated portions327-1are welded to each other and are connected to the plurality of first anode uncoated portions127. A plurality of fourth anode uncoated portions327-2are welded to each other and are connected to the plurality of second anode uncoated portions227. Here, the plurality of first anode uncoated portions127and the plurality of third anode uncoated portions327-1may also be connected to each other by welding, and the plurality of second anode uncoated portions227and the plurality of fourth anode uncoated portions327-2may also be connected to each other by welding.

In addition, the second anode uncoated portion227and the fourth anode uncoated portion327-2are connected to the anode tab230positioned on the first side of the second electrode assembly200by the first anode conductive member510. That is, one end of the first anode conductive member510that is positioned on a first side of the first anode conductive member510is connected to the anode tab230, and the other end of the first anode conductive member510that is positioned on a second side of the first anode conductive member510is connected to the second anode uncoated portion227and the fourth anode uncoated portion327-2. The anode conductive member510not only connects the second anode uncoated portion227to the anode tab230to provide a movement path of the current generated from the second electrode assembly200, but also connects the fourth anode uncoated portion327-2to the anode tab230to provide a movement path of the current generated from the third electrode assembly300. The first anode conductive member510and the anode uncoated portions227and327-2, and the first anode conductive member510and the anode tab230may be connected to each other by welding, respectively.

In addition, the first anode uncoated portion127and the third anode uncoated portion327-1are connected to the second anode uncoated portion227and the fourth anode uncoated portion327-2by the second anode conductive member520. That is, one end of the second anode conductive member520that is positioned on a first side of the second anode conductive member520is connected to the second anode uncoated portion227and the fourth anode uncoated portion327-2, and the other end of the second anode conductive member520that is positioned on a second side of the second anode conductive member520is connected to the first anode uncoated portion127and the third anode uncoated portion327-1. The second anode conductive member520not only connects the third anode uncoated portion327-1to the second anode uncoated portion227and the fourth anode uncoated portion327-2to provide a movement path of the current generated from the third electrode assembly300, but also connects the first anode uncoated portion127to the second anode uncoated portion227and the fourth anode uncoated portion327-2to provide a movement path of the current generated from the first electrode assembly100. The second anode conductive member520and the anode uncoated portions127and327-1, and the second anode conductive member520and the anode uncoated portions227and327-2may be connected to each other by welding, respectively.

As such, in the case where the cathode conductive members410and420provide not only the movement path of the current generated from the first electrode assembly100but also the movement paths of the currents generated from the second electrode assembly200and the third electrode assembly300, and the anode conductive members510and520provide not only the movement path of the current generated from the second electrode assembly200but also the movement paths of the currents generated from the first electrode assembly100and the third electrode assembly300, cross sectional areas of the current movement paths are increased, and a resistance of the long width secondary battery is thus reduced.

The cathode conductive members410and420and the anode conductive members510and520may be formed in a plate shape. The conductive member formed in a plate shape allows the cross sectional areas of the current movement paths to be increased, and the resistance of the long width secondary battery is easily reduced.

As illustrated inFIG.5, the first cathode conductive member410may provide the current movement path at a lower portion of the first electrode assembly100, and the second cathode conductive member420may provide the current movement path at a lower portion of the third electrode assembly300. However, the first cathode conductive member410may provide the current movement path at an upper portion or one side surface portion of the first electrode assembly100, and the second cathode conductive member420may provide the current movement path at an upper portion or one side surface portion of the third electrode assembly300.

In addition, the first anode conductive member510may provide the current movement path at a lower portion of the second electrode assembly200, and the second anode conductive member520may provide the current movement path at the lower portion of the third electrode assembly300. However, the first anode conductive member510may provide the current movement path at an upper portion or one side surface portion of the second electrode assembly200, and the second anode conductive member520may provide the current movement path at the upper portion or one side surface portion of the third electrode assembly300.

Thicknesses of the cathode conductive members410and420and the anode conductive members510and520are closely related to the cross sectional areas of the current movement paths. That is, the cross sectional area of the current movement path may be increased in proportion to the thickness of each of the cathode conductive members410and420and each of the anode conductive members510and520. As a result, the resistance of the long width secondary battery may be reduced. However, since thicknesses of the cathode current collectors115,215, and315and the anode current collectors125,225, and325are also related to the cross sectional areas of the current movement paths, in order to greatly reduce the resistance of the long width secondary battery, it is preferable that the thickness of each of the cathode conductive members410and420is larger than those of the cathode current collectors115,215, and315, and the thickness of each of the anode conductive members510and520is larger than those of the anode current collectors125,225, and325.

The cathode conductive members410and420and the anode conductive members510and520formed only in a plate shape are illustrated inFIG.5, but the cathode conductive members410and420and the anode conductive members510and520may be formed in an electric wire shape. Since the electric wire shape has a cross sectional area smaller than that of the plate shape, the electric wire shape has a low degree of contribution to reduction in resistance of the long width secondary battery, but may allow the production of a small and lightweight long width secondary. Moreover, the cathode conductive members410and420and the anode conductive members510and520formed in an electric wire shape have a high energy density, and thus the long width secondary battery may provide a relatively high electrical output.

As described above, one end of the first cathode conductive member410that is positioned on the first side of the first cathode conductive member410is connected to the first cathode uncoated portion117and the third cathode uncoated portion317-1, one end of the second cathode conductive member420that is positioned on the first side of the second cathode conductive member420is connected to the second cathode uncoated portion217and the fourth cathode uncoated portion317-2, and the other end of the second cathode conductive member420that is positioned on the second side of the second cathode conductive member420is connected to the first cathode uncoated portion117and the third cathode uncoated portion317-1. In addition, the other end of the first anode conductive member510that is positioned on a second side of the first anode conductive member510is connected to the second anode uncoated portion227and the fourth anode uncoated portion327-2, one end of the second anode conductive member520that is positioned on the first side of the second anode conductive member520is connected to the second anode uncoated portion227and the fourth anode uncoated portion327-2, and the other end of the second anode conductive member520that is positioned on the second side of the second anode conductive member520is connected to the first anode uncoated portion127and the third anode uncoated portion327-1. In this case, in general, the conductive member and the uncoated portion are connected to each other by ultrasonic welding. When the conductive member and the uncoated portion are formed of the same materials, the ultrasonic welding may be smoothly performed. Therefore, it is preferable that the first cathode current collector115, the second cathode current collector215, the third cathode current collector315, the first cathode conductive member410, and the second cathode conductive member420are formed of the same materials, and the first anode current collector125, the second anode current collector225, the third anode current collector325, the first anode conductive member510, and the second anode conductive member520are formed of the same materials. For example, when the cathode current collectors115,215, and315are formed of an aluminum material, it is preferable that the cathode conductive members410and420are also formed of the aluminum material. When the anode current collectors125,225, and325are formed of a copper material, it is preferable that the anode conductive members510and520are also formed of the copper material.

FIG.6Ais a front view of the support member supporting the electrode assembly ofFIG.5, andFIG.6Bis a rear view of the support member supporting the electrode assembly of theFIG.5.FIG.7is a plan view of the support member supporting the electrode assembly ofFIG.5, andFIG.8is a view illustrating a state in which the electrode assembly ofFIG.5is mounted on the support member.

As illustrated inFIGS.6A to8, the long width secondary battery according to the second exemplary embodiment of the present invention may further include a support member600supporting the first electrode assembly100, the second electrode assembly200, and the third electrode assembly300. The support member600is disposed at the lower portions of the electrode assemblies100,200, and300, and supports the electrode assemblies100,200, and300, such that the support member600may contribute to improving a strength of the long width secondary battery.

In addition, the cathode conductive members410and420and the anode conductive members510and520may be provided on the support member600. More specifically, a plurality of steps650-1and650-2are provided on the support member600. The first cathode conductive member410extends from the first step650-1toward one side of the support member600. The second cathode conductive member420extends over the first step650-1and the second step650-2. Here, the first cathode conductive member410and the second cathode conductive member420may be separately formed and then connected to each other by welding, or may be integrally formed. In addition, the first anode conductive member510extends from the second step650-2toward the other side of the support member600. The second anode conductive member520extends over the first step650-1and the second step650-2. Here, the first anode conductive member510and the second anode conductive member520may be separately formed and then connected to each other by welding, or may be integrally formed.

In this case, the cathode conductive members410and420may be provided at a position corresponding to the cathode uncoated portions117,217,317-1, and317-2, for example, a portion biased forward of the support member600, in order to connect the cathode uncoated portions117,217,317-1, and317-2. In addition, the anode conductive members510and520may be provided at a position corresponding to the anode uncoated portions127,227,327-1, and327-2, for example, a portion biased rearward of the support member600, in order to connect the anode uncoated portions127,227,327-1, and327-2.

The first electrode assembly100may be disposed one side of the support member600based on one of the plurality of steps650-1and650-2, that is, the first step650-1. The second electrode assembly200may be disposed the other side of the support member600based on the other one of the plurality of steps650-1and650-2, that is, the second step650-2. In addition, the third electrode assembly300may be disposed between the first step650-1and the second step650-2.

The first cathode uncoated portion117and the third cathode uncoated portion317-1may be connected to the first cathode conductive member410and the second cathode conductive member420by welding at the first step650-1. In addition, the second cathode uncoated portion217and the fourth cathode uncoated portion317-2may be connected to the second cathode conductive member420by welding at the second step650-2.

The second anode uncoated portion227and the fourth anode uncoated portion327-2may be connected to the first anode conductive member510and the second anode conductive member520by welding at the second step650-2. In addition, the first anode uncoated portion127and the third anode uncoated portion327-1may be connected to the second anode conductive member520by welding at the first step650-1.

As such, the electrode assemblies100,200, and300are disposed on the support member600provided with the steps650-1and650-2, the cathode uncoated portions117,217,317-1and317-2are connected to the cathode conductive members410and420at the steps650-1and650-2, and the anode uncoated portions127,227,327-1, and327-2are connected to the anode conductive members510and520, such that a strength and an assembly efficiency of the long width secondary battery may be increased.

In the second exemplary embodiment of the present invention. It has been described that three electrode assemblies are sequentially disposed; however, the number of electrode assemblies sequentially disposed may be four or more. That is, inFIG.5, it has been described that only one electrode assembly (that is, the third electrode assembly300) is disposed between the first electrode assembly100and the second electrode assembly200; however, a plurality of electrode assemblies may be disposed therebetween. The plurality of electrode assemblies disposed between the first electrode assembly100and the second electrode assembly200may be the third electrode assembly300. In addition, when the number of electrode assemblies sequentially disposed is four or more, a length of the support member600is required to be increased in proportion to the number of electrode assemblies, and the number of steps provided on the support member600is also required to be three or more.

As set forth above, according to the present invention, not only the movement path of the current generated from the first electrode assembly, but also the movement path of the current generated from the second electrode assembly are provided by the cathode conductive member, and not only the movement path of the current generated from the second electrode assembly, but also the movement path of the current generated from the first electrode assembly are provided by the anode conductive member, such that the cross sectional areas of the current movement paths are increased. Therefore, the resistance of the long width secondary battery may be reduced.

Further, according to the present invention, the electrode assembly is disposed on the support member provided with the step, and the cathode uncoated portion and the cathode conductive member are connected to each other at the step, and the anode uncoated portion and the anode conductive member are connected to each other at the step, such that a strength and an assembly efficiency of the long width secondary battery may be improved.

Although the present invention has been described with reference to the exemplary embodiments and the accompanying drawings, it is not limited to the above-mentioned exemplary embodiments but may be variously modified and changed from the above description by those skilled in the art to which the present invention pertains. Therefore, the technical spirit of the present invention should be understood only by the claims, and all of the equivalences and equivalent modifications to the claims are intended to fall within the technical spirit of the present invention.