Rechargeable battery

A rechargeable battery includes: an electrode assembly in a case; a cap plate coupled to an opening of the case; a rivet electrically connected to the electrode assembly, the rivet including: a first rivet flange; and a second rivet flange; and a gasket between the rivet flange and the cap plate, the gasket including: a first gasket flange configured to be coupled with the first rivet flange; and a second gasket flange configured to be coupled with the second rivet flange.

BACKGROUND

Embodiments of the present invention generally relate to a rechargeable battery, and more particularly, to a rechargeable battery having an improved gasket and terminal structure.

2. Description of the Related Art

A rechargeable battery is a battery that can be recharged, unlike a primary battery that cannot be recharged. A low-capacity rechargeable battery may be used for small portable electronic devices such as a mobile phone, a notebook computer, and a camcorder and a large-capacity battery may be used as a power supply for driving a motor such as a hybrid or electric car or a large-capacity power storage device.

Recently, a high-output rechargeable battery using a non-aqueous electrolyte solution having high energy density has been developed. The high-output rechargeable battery is configured of a large-capacity battery module in which a plurality of rechargeable batteries are connected to each other in series so as to be used to motors for devices requiring large power, for example, an electric car, a hybrid car, or the like.

The rechargeable battery may be configured to have a cylindrical shape, a square shape, or the like.

However, in some circumstances, the electrolyte solution in a case of the rechargeable battery infiltrates between an electrode terminal and a cap plate, thereby causing an electrical short between the electrode terminal and the cap plate.

In addition, the electrolyte solution in the case of the rechargeable battery may leak outside of the case.

SUMMARY

Aspects of embodiments of the present invention are directed toward a rechargeable battery capable of preventing or reducing the likelihood of an electrical short between an electrode terminal and a cap plate by blocking an electrolyte solution in a case of the rechargeable battery from infiltrating between the electrode terminal and the cap plate.

In addition, aspects of embodiments of the present invention are directed toward a rechargeable battery capable of preventing or protecting an electrolyte solution from being leaked to the outside of a case.

According to an embodiment of the present invention, a rechargeable battery includes: an electrode assembly in a case; a cap plate coupled to an opening of the case; a rivet electrically connected to the electrode assembly, the rivet including: a first rivet flange; and a second rivet flange; and a gasket between the rivet flange and the cap plate, the gasket including: a first gasket flange configured to be coupled with the first rivet flange; and a second gasket flange configured to be coupled with the second rivet flange.

The first gasket flange may be greater than or equal to the first rivet flange in size.

The second gasket flange may be greater than or equal to the second rivet flange in size.

The rivet may further include a pillar part extending through the cap plate.

The gasket may have a through hole and the pillar part of the rivet may extend through the through hole of the gasket.

The first rivet flange may extend in a first direction and a second direction perpendicular to the first direction, the second rivet flange may extend in the second direction, the second rivet flange may extend from a side edge of the first rivet flange, the first gasket flange may extend in the first direction and the second direction, the second gasket flange may extend in the second direction, and the second gasket flange may extend from a side edge of the first gasket, the gasket may include a gasket body extending in a third direction perpendicular to the first and second directions, and the through hole of the gasket may be formed through the gasket body in the third direction.

The rechargeable battery may further include an insulating member having a through hole, and the gasket body may extend through the through hole of the insulating member.

The first rivet flange may extend in a first direction and a second direction perpendicular to the first direction, the second rivet flange may extend in the second direction, the second rivet flange may extend from a side edge of the first rivet flange, the first gasket flange may extend in the first direction and the second direction, the second gasket flange may extend in the second direction, and the second gasket flange may extend from a side edge of the first gasket.

The second gasket flange may include a bent portion extending in a third direction perpendicular to the first and second directions and covering an end of the second rivet flange.

The rivet may further include: a third rivet flange extending in the second direction, the third rivet flange extending from another side edge of the first rivet flange facing oppositely away from the side edge from which the second rivet flange extends.

The gasket may further include: a third gasket flange extending in the second direction, the third gasket flange extending from another side edge of the first gasket flange facing oppositely away from the side edge from which the second gasket flange extends and configured to be coupled with the third rivet flange.

The third gasket flange may be greater than or equal to the third rivet flange in size.

The third gasket flange may include a bent portion extending in a third direction perpendicular to the first and second directions and covering an end of the third rivet flange.

The gasket may further include a rivet flange coupling part including: a first rivet flange coupling lip extending from the first gasket flange in a third direction perpendicular to the first and second directions; and a second rivet flange coupling lip extending from the second gasket flange in the third direction.

The second gasket flange may be thinner than the first gasket flange.

The rechargeable battery may further include an insulating member having a coupling groove configured to house the rivet flange and the gasket, wherein the insulating member may be between the gasket and the cap plate, and the gasket and the first and second rivet flanges are between the cap plate and the insulating member.

The rechargeable battery may further include a current collector, wherein the rivet may be electrically coupled to the electrode assembly via the current collector, the current collector comprising a terminal coupling part and an electrode coupling part.

The insulating member may include a coupling groove configured to house the terminal coupling part between the coupling groove and the rivet flange.

The insulating member may further include a coupling ring at a side edge of the insulating member, the coupling ring encircling a portion of the electrode coupling part.

The cap plate may include a plurality of protruding grooves and the insulating member may include fixing protrusions configured to be respectively coupled with the protruding grooves.

DETAILED DESCRIPTION

In the drawings, dimensions of layers, regions, etc., are exaggerated for clarity. It will be understood that when one layer or one element is considered to as being “on” another element, it can be directly on the other element or intervening elements may also be present therebetween. Further, it will be understood that when one layer or one element is considered to as being “under” another element, it can be directly on (under) the other element or at least one intervening element may also be present therebetween. In addition, it will be understood that when one layer is considered to as being “between” two layers, it can be a unique layer between two layers or at least one other layer may also be present therebetween. Like reference numerals designate like elements throughout the specification and the drawings.

FIG. 1is a perspective view of a rechargeable battery according to a first exemplary embodiment of the present invention andFIG. 2is a cross-sectional view taken along line II-II ofFIG. 1.

Referring toFIGS. 1 and 2, a rechargeable battery100according to an exemplary embodiment of the present invention includes a plurality of electrode assemblies10formed by winding a first electrode11and a second electrode12together, having the separator13disposed between the first electrode11and the second electrode12, a case26in which the electrode assemblies10are embedded (or housed), a first terminal part30and a second terminal part40electrically connected with the electrode assemblies10, a cap plate20coupled with an opening formed in the case26, and first and second insulating members60and80installed in the case26.

The rechargeable battery100according to one exemplary embodiment is a lithium ion rechargeable battery. Herein, a squared rechargeable battery will be described by way of example. However, embodiments of the present invention are not limited thereto and the present invention may be applied to a battery such as a lithium polymer battery, or the like.

In addition, the first electrode11may be a negative electrode and the second electrode12may be a positive electrode, or vice versa. However, for the sake of convenience, in the exemplary embodiment, the first electrode11and the second electrode12will be described instead of the negative electrode and the positive electrode, respectively, but embodiments of the present invention are not limited thereto.

The electrode assembly10is formed by winding the first electrode11, the second electrode12, and the separator13together to form a jelly roll structure. The first electrode11and the second electrode12each include a current collector formed of a thin metal foil and an active material coated on a surface of the current collector. In addition, the first electrode11and the second electrode12may be partitioned into a coated part in which an active material is coated on the current collector and a first electrode non-coated part11aand a second electrode non-coated part12ain which the active material is not coated on the current collector. The coated part forms a substantial portion of the first electrode11and the second electrode12in the electrode assembly10, and each of the first electrode non-coated part and the second non-coated part11aand12ais disposed at a respective side (e.g., opposite ends) of the coated part in the jelly roll structure.

However, embodiments of the present invention are not limited thereto. The above-described electrode assembly10may be formed in a stacked structure, having the separator13between the first electrode11and the second electrode12formed of a plurality of sheets.

The first electrode non-coated part11aof the electrode assembly10is electrically connected to the first terminal part30via a first electrode current collecting member (or current collector)50, and the second electrode non-coated part12ais electrically connected to the second terminal part40via a second electrode current collecting member (or current collector)70. Therefore, the first terminal part30may include a first electrode terminal, and the second terminal part40may include a second electrode terminal.

The case26is formed in an approximately rectangular parallelepiped (or rectangular prism or cuboid) shape, and one surface thereof is provided with an opened opening.

However, embodiments of the present invention are not limited thereto, and the case may be formed in various suitable shapes, such as a cylindrical shape, a pouch shape, or the like.

According to one embodiment of the present invention, the cap plate26is formed of a thin plate and is coupled with the opening of the case26to seal the opening. Further, the cap plate20is provided with an electrolyte solution inlet21through which the electrolyte solution may be injected into the sealed case26, wherein the electrolyte solution inlet21is sealed by a sealing closure22after the electrolyte solution is injected. In addition, the cap plate20is provided with a vent hole23mounted with a vent plate24which is adapted to fracture when an internal pressure of the sealed case26exceeds a pressure (e.g., a set pressure).

The first and second terminal parts30and40include first and second rivets31and41, first and second terminal plates32and42, a first terminal insulating member33disposed between the first and second terminal plates32and42and the cap plate20, a conductive connection member43, and first and second gaskets34and44. In this configuration, the first and second rivets31and41include first and second pillar parts31aand41aand first and second flange parts31band41b.

According to one exemplary embodiment of the present invention, because the cap plate20is electrically connected to the second terminal part40by the conductive connection member43, the cap plate20may have the polarity of the positive electrode or the negative electrode.

Further, the first and second electrode current collecting members50and70include first and second electrode coupling parts51and71(see, e.g.,FIG. 3) coupled with the first and second electrodes11and12and first and second terminal coupling parts52and72(see, e.g.,FIG. 3) coupled with the first and second terminal parts30and40.

In this configuration, according to one exemplary embodiment of the present invention, the structure of the first and second terminal parts30and40, and the structure of the first and second electrode current collecting members50and70and first and second insulating members60and80are substantially the same. Therefore, the description of the second terminal part40, the second electrode current collecting member70, and the second insulating member80will be omitted.

However, the first terminal part30according to one exemplary embodiment of the present invention may include a cylindrically-shaped terminal rather than a plate-shaped terminal.

Instead of the conductive connection member43, an insulating connection member may be disposed between the cap plate20and the second rivet41. Therefore, in some embodiments of the present invention, the cap plate20is not be electrically connected to the second terminal part40.

FIG. 3is a partially exploded perspective view of a rechargeable battery according to the first exemplary embodiment of the present invention.

Referring toFIG. 3, according to one exemplary embodiment of the present invention, the first rivet31includes a pillar part31aand a rivet flange part31b.

In more detail, the rivet flange part31bmay include a first rivet flange311band a second and third rivet flanges312band313b. In this configuration, the first rivet flange311bmay protrude in a direction (x-axis direction) approximately perpendicular to a height direction (y-axis direction) of the pillar part31aat one end of the pillar part31a. Further, the second rivet flange312bprotrudes in a direction (x-axis direction) approximately perpendicular to a height direction (y-axis direction) of the pillar part31aat one end of the first rivet flange311band a third rivet flange313bmay protrude from the other end thereof positioned at an opposite side of the one end thereof.

In addition, the first gasket34according to the exemplary embodiment may include a body34ain which a through hole is formed and a gasket flange part34b.

In more detail, the gasket flange part34bmay include a first gasket flange341band second and third gasket flanges342band343b. In this configuration, the first gasket flange341bmay protrude in a direction (x-axis direction) approximately perpendicular to a height direction (y-axis direction) of the body34aat one end of the body34a. Further, the second gasket flange342bprotrudes in a direction (x-axis direction) approximately perpendicular to a height direction (y-axis direction) of the body34aat one end of the first gasket flange341band the third gasket flange343bprotrudes from the other end of the first gasket flange341b(e.g., positioned at an opposite side of the one end of the first gasket flange341b)

In addition, a first insulating member60according to one embodiment of the present invention includes a coupling groove61, a plurality of fixing protrusions62fixed to a plurality of protruding grooves25formed on the cap plate20, and a through hole63through which the first rivet31penetrates. In this configuration, the coupling groove61may be formed on one surface of the first insulating member60opposite to (e.g., facing away from) the electrode assembly10, as shown inFIG. 2.

Moreover, the first electrode current collecting member50may include a first electrode coupling part51and a first terminal coupling part52that are coupled with the first electrode11.

Hereinafter, the coupling relationship between the first rivet31and the first gasket34according to the exemplary embodiment will be described in more detail.

In the first insulating member60, the fixing protrusions62may be fixed to the protrusion grooves25formed on the cap plate20.

Further, the first gasket34may be inserted into the coupling groove61formed on the bottom of the first insulating member60. In this configuration, the body34aof the gasket34is inserted into the through hole63and the coupling groove61may receive the first gasket flange341band the second gasket flange342bformed in the first gasket34.

In this case, the second gasket flange part342bof the first gasket34may be disposed in parallel with the length direction (x-axis direction) of the cap plate20.

In addition, the pillar part31aof the first rivet31may be disposed to penetrate through the body34aof the first gasket34, the through hole63of the first insulating member60, and the terminal hole26formed on the cap plate20, and the first rivet flange311b, the second rivet flange312b, and the third rivet flange313bmay be received in the coupling groove61. In this case, the second rivet flange312band the third rivet flange313bare closely disposed to the second gasket flange342band the third gasket flange343b, respectively, so as to be disposed at the coupling groove61.

Therefore, the first rivet flange311bof the first rivet31, the first gasket flange341bof the first gasket34, the second and third rivet flanges312band313bof the first rivet, and the second and third gasket flanges342band343bof the first gasket34may be closely disposed to each other at the coupling groove61.

In this configuration, the size of the first gasket flange341bmay be greater than or equal to the size of the first rivet flange311b, the size of the second gasket flange342bmay be greater than or equal to the size of the second rivet flange312b, and the size of the third gasket flange343bmay be greater than or equal to the size of the third rivet flange313b.

Consequently, the size of the gasket flange part34bof the first gasket34may be greater than or equal to the size of the rivet flange part31bof the first rivet31.

Referring again toFIG. 2, the end of the pillar part31aof the first rivet31may be coupled with the first terminal plate32by the rivet, and the first terminal coupling part52of the first electrode current collecting member50may be inserted into the coupling groove61to be coupled with the first rivet31by a weld, or the like.

Therefore, in one embodiment of the present invention, the first insulating member60is disposed between the electrode current collector10and the cap plate20by fixing the rivet flange part31bof the first rivet31to the coupling groove61.

The electrolyte solution injected into the case of the rechargeable battery100according to one exemplary embodiment may permeate into the coupling groove61of the first insulating member60or between the first insulating member60and the cap plate20, such that an electrical short is formed between the cap plate20and the first rivet31. In this case, since the size of the gasket flange part34baccording to the exemplary embodiment may be greater than or equal to the size of the rivet flange part31b, the adhesion between the gasket flange part34band the rivet flange part31bmay be more improved compared to a comparative example in which the size of the gasket flange part34bis smaller than the size of the rivet flange part31b.

Therefore, it is possible to prevent or reduce the risk of the electrolyte solution in the case26from leaking outside of the case26.

In addition, because the second gasket flange342bextending from one end of the first gasket flange341bis disposed close to the second rivet flange312band because the third gasket flange342bextending from an opposite end of the first gasket flange341bis disposed close to the third rivet flange313b, the electrolyte solution permeating into the first insulating member60passes between the second gasket flange342band the first insulating member60so as to reach the cap plate20.

Therefore, the adhesion between the rivet flange part31band the first gasket34is improved by the gasket flange part34bof the first gasket34according to the exemplary embodiment, and the length of the entire path through which the electrolyte needs to permeate into the first insulating member60to reach the cap plate20is increased, such that the risk of an electrical short between the cap plate20and the first rivet31due to the electrolyte solution can be reduced.

FIG. 4is a partially exploded perspective view of a rechargeable battery according to another embodiment of the present invention.

In this case, the rechargeable battery101according to the exemplary embodiment ofFIG. 4has the same structure as the rechargeable battery100according to the first exemplary embodiment, except for the first gasket34′, and therefore, a description of the same structure will be omitted.

Referring toFIG. 4, the first gasket34′ according to the exemplary embodiment may include a body34′ain which a through hole is formed and a gasket flange part34′b.

In more detail, the gasket flange part34′bmay include a first gasket flange341′b, a second gasket flange342′b, and a third gasket flange343′b.

In this configuration, the first gasket flange341′bmay protrude in a direction (x-axis direction) approximately perpendicular to a height direction (y-axis direction) of the body34′aat one end of the body34′a.

Further, the second gasket flange342′bmay protrude in a direction (x-axis direction) approximately perpendicular to a height direction (y-axis direction) of the body34′aat one end of the first gasket flange341′band the third gasket flange343′bmay protrude from the other end of the first gasket flange341′band may be positioned at an opposite side of the one end thereof.

In this configuration, the end of the second gasket flange342′bmay be bent downwardly to form a bent portion342′b1of the second gasket flange342′b. Similarly, the end of the third gasket flange343′bmay be bent downwardly to form a bent portion343′b1.

Therefore, the second and third gasket flanges342′band343′bmay also be closely disposed at the side of the second rivet flange312band the third rivet flange313b, respectively.

As a result, it is possible to further improve the adhesion between the rivet flange31band the first gasket34′ by bent portions342′b1and343′b1of the second and third gasket flanges342′band343′baccording to the exemplary embodiment. Therefore, it is possible to prevent or protect the electrolyte solution in the case26from being leaked to the outside of the case26.

In addition, according to one exemplary embodiment, because the entire path through which the electrolyte solution permeates into the first insulating member60to reach the cap plate20is increased, the risk of an electrical short between the cap plate20and the first rivet31due to the electrolyte solution can be reduced.

FIG. 5is a partially exploded perspective view of a rechargeable battery according to a second exemplary embodiment of the present invention.

The rechargeable battery200according to the second exemplary embodiment has substantially the same structure as the rechargeable battery100according to the first exemplary embodiment, except for the first gasket34″, and therefore, the description of structures that are substantially the same will be omitted.

Referring toFIG. 5, a first gasket34″ according to the exemplary embodiment includes a body34″ain which a through hole is formed, a gasket flange part34″b, and a rivet flange coupling lip34″c.

According to the exemplary embodiment, the gasket flange part34″bincludes a first gasket flange341″b, a second gasket flange342″b, and a third gasket flange343″b.

However, the first gasket flange part341″b, the second gasket flange part342″b, and the third gasket flange part343″baccording to the exemplary embodiment have substantially the same structure as the first gasket flange341band the second gasket flange342bof the first gasket34according to the first exemplary embodiment and therefore, the descriptions of the substantially similar structures will be omitted.

Further, a rivet flange coupling lip34″caccording to the exemplary embodiment is disposed on the bottom (e.g., in a direction facing toward the first and second rivet flanges31bof rivet31) of the gasket flange part34″b.

In more detail, the rivet flange coupling lip34″cincludes a first rivet flange coupling lip341″cformed on the bottom of the first gasket flange341″b, a second rivet flange coupling lip342″cformed on the bottom of the second gasket flange342″b, and a third rivet flange coupling lip343″cformed on the bottom of the third gasket flange343″b.

Therefore, the first rivet flange311bis coupled with the first rivet flange coupling lip341″c, the second rivet flange312bis coupled with the second rivet flange coupling lip342″c, and the third rivet flange313bis coupled with the third rivet flange coupling lip343″c.

Therefore, according to the exemplary embodiment, the rivet flange31bis inserted into the rivet flange coupling lip34″c, such that the sides of the rivet flange31bare also closely disposed to the gasket flange part34″b.

Therefore, the adhesion between the gasket flange part34″band the rivet flange31bmay be more improved.

As a result, it is possible to prevent or reduce the risk of the electrolyte solution in the case26from being leaked outside of the case26.

In addition, because the entire path through which the electrolyte solution must permeate into the first insulating member60to reach the cap plate20is increased, the risk of an electrical short between the cap plate20and the first rivet31due to the electrolyte solution may be reduced.

FIG. 6is a partially exploded perspective view of a rechargeable battery according to a third exemplary embodiment andFIG. 7is a partial cross-sectional view according to a coupling state of the rechargeable battery ofFIG. 6.

In this embodiment, a rechargeable battery300according to the exemplary embodiment has substantially the same structure as the rechargeable battery200according to the second exemplary embodiment, except for a first insulating member90, and therefore, the description of the substantially similar structures will be omitted.

Referring toFIGS. 6 and 7, the first insulating member90according to the third exemplary embodiment includes a coupling groove91with which the first electrode current collecting member (or current collector)50is coupled and a plurality of fixing protrusions92fixed to the plurality of protruding grooves25formed on the cap plate20.

In this configuration, the coupling groove91according to the third exemplary embodiment is formed on a surface of the first insulating member90that is opposite to (e.g., facing) the cap plate20.

Therefore, as shown inFIG. 7, the first electrode coupling part51of the first electrode current collecting member50is received in the coupling groove91formed on the first insulating member90.

In addition, the first rivet31and the first gasket34″ are sequentially stacked in the coupling groove91.

Therefore, it is possible to more easily couple the first electrode current collecting member50, the first rivet31, and the first gasket34″.

Moreover, because the first electrode coupling part51of the first electrode current collecting member50is received in the coupling groove91, the first insulating member90according to the third exemplary embodiment may prevent or mitigate the contact between the first electrode coupling part51and the electrolyte solution. Therefore, it is possible to prevent or reduce the risk of an electrical short between the cap plate20and the first rivet31.

FIG. 8is a partially exploded perspective view of a rechargeable battery according to a modified example of a third exemplary embodiment.

In this case, a rechargeable battery301according to the modified third exemplary embodiment has substantially the same structure as the rechargeable battery300according to the third exemplary embodiment, except for a first electrode current collecting member coupling ring93of the first insulating member90and therefore, the description of substantially similar structures will be omitted.

Referring toFIG. 8, the first insulating member90according to the exemplary embodiment includes a first electrode current collecting member coupling ring93that extends from one side of the first insulating member90.

Therefore, one side of the first terminal coupling part52of the first electrode current collecting member50is fixed by the first electrode current collecting member coupling ring93.

As a result, the first electrode current collecting member50may be more stably coupled with the first insulating member90by the first electrode current collecting member coupling ring93.

As shown inFIGS. 3,4,5,6, and8, the first, second, and third rivet flanges and first, second, and third gasket flanges have substantially rectangular shapes. However, embodiments of the present invention are not limited thereto. For example, in other embodiments of the present invention, the first, second, and third rivet flanges may be circular, oval, or triangular in shape and the first, second, and third gasket flanges may have corresponding shapes.