Rechargeable battery

A rechargeable battery includes an electrode assembly including a first electrode, a second electrode, and a separator between the first electrode and the second electrode, a case accommodating the electrode assembly, a cap plate coupled to the case, a first current collector coupled to the first electrode of the electrode assembly, and a first terminal assembly. The first terminal assembly includes a first terminal coupled to the first current collector and having a first fixed groove or a first fixed protrusion, and a second terminal having a second fixed groove coupled to the first fixed protrusion or a second fixed protrusion coupled to the first fixed groove.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2013-0113342 filed in the Korean Intellectual Property Office on Sep. 24, 2013, the entire content of which is incorporated herein by reference.

BACKGROUND

Aspects of the present invention relate generally to a rechargeable battery.

2. Description of the Related Art

A rechargeable battery has the characteristic that it may be recharged after discharge, differing from a primary battery that is incapable of being recharged. Small-capacity rechargeable batteries are used for small portable electronic devices such as mobile phones, notebook computers, camcorders, etc., while large-capacity rechargeable batteries are used as a motor-driving power source for larger devices, such as hybrid vehicles or large-capacity power storage devices.

Presently, high powered rechargeable batteries using a non-aqueous electrolyte with high energy density have been developed and formed into a large capacity rechargeable battery by coupling a plurality of rechargeable batteries in series for use in driving a motor of a device, for example, a motor of an electric vehicle requiring high electrical power. These rechargeable batteries can be cylindrical or angular in shape.

Rechargeable batteries generally include an electrode assembly installed inside a case and to/from which a current may be charged or discharged. An electrode terminal is electrically connected to the electrode assembly often via a current collector. The electrode terminal generally includes a positive terminal and a negative terminal, and is coupled and fixed to a cap plate for closing and sealing an opening of the case of the rechargeable battery. The electrode terminal used for this rechargeable battery can be one of a rivet-type electrode terminal or a bolt-type electrode terminal. To fix a rivet-type electrode terminal to the cap plate, the rivet-type electrode terminal must first be fixed to the cap plate, and then one side of the rivet-type electrode terminal contacting the cap plate must be rivet-processed and welded, making the combination process of fixing the electrode terminal complicated.

For rechargeable batteries, structures configured with different materials have been shown to have excellent properties, similar to a combination degree of structures combined through friction welding compared to laser welding. In contrast, it has been shown that combining structures formed with the same material through laser welding is more efficient than the same combination through friction welding.

When the rivet-type electrode terminal and the cap plate are formed with different materials, they are generally rivet-processed, and because friction welding is not easy to perform on a part having different materials coupled to the cap plate, it may be necessary to perform laser welding on the rivet-processed part. Therefore, in these rechargeable batteries, a structure made of the same material as the cap plate is coupled to one side of the rivet-type electrode terminal coupled to the cap plate through friction welding, and the structure is rivet-processed and then laser welded on the rivet-processed part. As a result, when the rivet-type electrode terminal and the cap plate are formed with different materials, the process for fixing the electrode terminal to the cap plate becomes complicated.

SUMMARY

Aspects of the present invention relate generally to a rechargeable battery, and more particularly to a rechargeable battery having an improved terminal configuration.

An embodiment of the present invention provides a rechargeable battery including an electrode assembly having a first electrode, a second electrode, and a separator between the first electrode and the second electrode, a case accommodating the electrode assembly, a cap plate coupled to the case, a first current collector coupled to the first electrode of the electrode assembly, and a first terminal assembly. The first terminal assembly may include a first terminal coupled to the first current collector and having a first fixed groove or a first fixed protrusion, and a second terminal having a second fixed groove coupled to the first fixed protrusion or a second fixed protrusion coupled to the first fixed groove.

In an embodiment, the first fixed groove includes a first spiral groove, and the second fixed protrusion includes a second thread configured to engage the first spiral groove.

In another embodiment, the second fixed groove includes a second spiral groove, and the first fixed protrusion includes a first thread configured to engage the second spiral groove.

The first terminal may be made of a first material, and the second terminal may be made of a second material different from the first material.

The first terminal assembly may further include a first terminal plate on the cap plate, the first current collector may be made of the first material, and the first terminal plate made be made of the second material.

In an embodiment, the first material is copper, and the second material is aluminum.

The rechargeable battery may further include a corrosion preventing member between the first terminal and the second terminal.

The corrosion preventing member may be coated on the first fixed protrusion or on the second fixed protrusion.

The rechargeable battery according to an embodiment further includes a second current collector coupled to the second electrode, and a second terminal assembly. The second terminal assembly may include a third terminal coupled to the second current collector and having a third fixed groove or a third fixed protrusion, and a fourth terminal having a fourth fixed groove coupled to the third fixed protrusion or a fourth fixed protrusion coupled to the third fixed groove.

In an embodiment, the third fixed groove includes a third spiral groove, and the fourth fixed protrusion includes a fourth thread configured to engage the third spiral groove.

In another embodiment, the fourth fixed groove includes a fourth spiral groove, and the third fixed protrusion includes a third thread configured to engage the fourth spiral groove.

According to aspects of the present invention, a rechargeable battery having a terminal that is easily assembled and is easily and stably combined with the cap plate is provided, improving productivity and durability of the rechargeable battery including the terminal that is easily assembled and is easily and stably combined with the cap plate.

DETAILED DESCRIPTION

FIG. 1shows a perspective view of a rechargeable battery according to a first embodiment of the present invention, andFIG. 2shows a cross-sectional view of the rechargeable battery shown inFIG. 1taken along line II-II.

Referring toFIGS. 1 and 2, a rechargeable battery100includes an electrode assembly10, a case25in which the electrode assembly10is installed, a first terminal assembly30and a second terminal assembly40electrically connected to the electrode assembly10, a cap plate20, and a first bottom insulating member60and a second bottom insulating member80.

The rechargeable battery100in the first embodiment is an angular lithium ion secondary battery. However, the present invention is not restricted thereto, and embodiments of the present invention are applicable to a variety of types and shapes of rechargeable batteries, including a cylindrical or lithium polymer battery.

The electrode assembly10may be a jellyroll having a spirally wound first electrode11, second electrode12, and separator13assembly.

Further, in an embodiment, an insulation tape14is coupled to a surface of the electrode assembly10to insulate the electrode assembly10from the case25.

In this embodiment, the first electrode11is a negative electrode and the second electrode12is a positive electrode. However, the present invention is not restricted to this embodiment, and the first electrode11can be a positive electrode with the second electrode12being a negative electrode, for example.

The first electrode11and the second electrode12according to this embodiment are each divided into a coated region having an active material coated on a current collector, and a first electrode uncoated region11aand a second electrode uncoated region12a, respectively on sides of the coated region of the first and second electrodes11and12without the active material coated on the current collector.

In these embodiments, the first terminal assembly30is electrically connected to the first electrode uncoated region11aof the electrode assembly10with a first current collector50as a medium, and the second terminal assembly40is electrically connected to the second electrode uncoated region12awith a second current collector70as a medium.

The first terminal assembly30according to these embodiments includes a first bottom terminal31(hereinafter, “first terminal”), a first top terminal32(hereinafter, “second terminal”), a first terminal plate33, a first terminal insulating member34, and a first gasket35between the first terminal31and the cap plate20.

The second terminal assembly40according to these embodiments includes a second bottom terminal41(hereinafter, “third terminal”), a second top terminal42(hereinafter, “fourth terminal”), a second terminal plate43, a second connecting plate44, and a second gasket45between the third terminal41and the cap plate20. In an embodiment, the second connecting plate44can be made from a conductive material such that the cap plate20and the case25can be electrically connected to the second electrode12through the second connecting plate44.

Embodiments of the current invention are not restricted to the embodiments of the first terminal assembly30and the second terminal assembly40as described for the rechargeable battery100, and in some embodiments, may include the structure of only one of the first terminal assembly30or the second terminal assembly40for the rechargeable battery100as described. In an embodiment, for example, one of the first terminal assembly30or the second terminal assembly40may exclude the first terminal31, the second terminal32, the third terminal41, and/or the fourth terminal42, but instead include a rivet-type terminal or a bolt-type terminal. Therefore, in other embodiments, the rechargeable battery100may include only one of the first terminal assembly30or the second terminal assembly40, or may include both the first terminal assembly30and the second terminal assembly40.

FIG. 3shows an exploded perspective view of a rechargeable battery according to the first embodiment of the present invention, andFIG. 4shows a partial cross-sectional view of the rechargeable battery according to the first embodiment of the present invention.

Referring to the embodiments shown inFIGS. 3 and 4, the first terminal31of the first terminal assembly30includes a first terminal column31ahaving a first fixed groove31a1, and a first terminal flange31bprotruding from an end of the first terminal column31a.

In this embodiment, the second terminal32of the first terminal assembly30includes a second terminal head32aand a second terminal column32bextending from the second terminal head32aand having a second fixed protrusion32b1.

In this embodiment, the second terminal column32bcan be inserted into the first fixed groove31a1in the first terminal column31aand can be coupled or fixed thereto. In an embodiment, the first fixed groove31a1includes a first spiral groove, and the second fixed protrusion32b1includes a second thread. Thus, when the second terminal column32bof the second terminal32is inserted into the first fixed groove31a1of the first terminal31according to this embodiment, a first thread of the second fixed protrusion32b1can be fastened to a first spiral groove of the first fixed groove31a1, for example via a threaded connection, and can be coupled or fixed thereto.

In an embodiment, the second terminal column32bof the second terminal32is passed through a second terminal hole33aof the first terminal plate33and is then inserted into the first fixed groove31a1of the first terminal31, and the second terminal head32aof the second terminal32is fixed to a second terminal groove33bdefining an area around the second terminal hole33a. In this embodiment, when fixed to the second terminal groove33b, the second terminal head32acan be coupled to the first terminal plate33through laser welding.

In these embodiments, by controlling a torque force or rotation of the second terminal32, the torque or rotation of the coupled second terminal32and first terminal31can also be controlled, and thus a compression rate of the first gasket35positioned between the first terminal31and the cap plate20is also controlled such that the first gasket35can be adequately sealed.

Further, a process for coupling the first terminal assembly30by, for example, engaging a threaded connection between the first terminal31and the second terminal32, is simplified, and a process of installing the first terminal assembly30on the cap plate20is facilitated, thereby improving productivity of manufacturing the rechargeable battery100.

In an embodiment, the third terminal41of the second terminal assembly40includes a third terminal column41ahaving a third fixed groove41a1, and a third terminal flange41bprotruding from an end of the third terminal column41a.

In an embodiment, the fourth terminal42of the second terminal assembly40includes a fourth terminal head42aand a fourth terminal column42bextending from the fourth terminal head42aand having a fourth fixed protrusion42b1. In this embodiment, the fourth terminal column42bcan be inserted into the third fixed groove41a1in the third terminal column41aand can be coupled or fixed thereto. In an embodiment, the third fixed groove41a1includes a first spiral groove, and the fourth fixed protrusion42b1includes a second thread. Thus, when the fourth terminal column42bof the fourth terminal42is inserted into the third fixed groove41a1of the third terminal41according to this embodiment, the first thread of the fourth fixed protrusion42b1can be fastened to the first spiral groove of the third fixed groove41a1, for example via a threaded connection, and can be coupled or fixed thereto.

In an embodiment, the fourth terminal column42bof the fourth terminal42is passed through a second terminal hole43ain the second terminal plate43and is then inserted into the third fixed groove41a1of the third terminal41, and the fourth terminal head42aof the fourth terminal42is fixed to a fourth terminal groove43bdefining an area around the second terminal hole43a. In this embodiment, when fixed to the fourth terminal groove43b, the fourth terminal head42acan be coupled to the second terminal plate43through laser welding.

In these embodiments, by controlling a torque force or rotation of the fourth terminal42, a torque or rotation of the coupled fourth terminal42and third terminal41can also be controlled, and thus a compression rate of the second gasket45positioned between the third terminal41and the cap plate20is also controlled such that the second gasket45can be adequately sealed.

Further, a process for coupling the second terminal assembly40by, for example, engaging a threaded connection between the third terminal41and the fourth terminal42, is simplified, and a process of installing the second terminal assembly40on the cap plate20is facilitated, thereby improving productivity of manufacturing the rechargeable battery100.

As would be appreciated by those skilled in the art, the first terminal through the fourth terminal (31,32,41, and42) of the first terminal assembly30and the second terminal assembly40can have other configurations that are different from those embodiments described above.

A configuration of first and second terminal assemblies according to another embodiment of the present invention is described in detail.

FIG. 5shows a partial cross-sectional view of a rechargeable battery according to a second embodiment of the present invention.

The rechargeable battery200according this embodiment has the same configuration as the first terminal assembly30according to the first embodiment, except for a first bottom terminal131(hereinafter, “first terminal”) and a first top terminal132(hereinafter, “second terminal”) of the first terminal assembly130of the rechargeable battery200according to the second embodiment. Therefore, no detailed description on the same configurations of the first terminal assembly30according to the first embodiment of the present invention will be provided.

In this embodiment, the first terminal131of the first terminal assembly130includes a first terminal column131ahaving a first fixed protrusion131a1, and a first terminal flange131bprotruding from an end of the first terminal column131a.

The second terminal132of the first terminal assembly130includes a second terminal head132aand a second terminal column132bextending from the second terminal head132aand having a second fixed groove132b1.

In this embodiment, the first terminal column131acan be inserted into the second fixed groove132b1in the second terminal column132b, and can then be coupled or fixed thereto. In an embodiment, the second fixed groove132b1includes a first spiral groove, and the first fixed protrusion131a1includes a second thread. Thus, when the first terminal column131aof the first terminal131is inserted into the second fixed groove132b1of the second terminal132according to this embodiment, the first thread of the first fixed protrusion131a1can be fastened to the first spiral groove of the second fixed groove132b1, for example via a threaded connection, and can be coupled or fixed thereto.

In these embodiments, by controlling a torque force or rotation of the first terminal131, the torque or rotation of the coupled first terminal131and second terminal132can be controlled, and thus a compression rate of the first gasket35positioned between the first terminal131and the cap plate20is also controlled such that the first gasket35can be adequately sealed.

Further, a process for coupling the first terminal assembly130by, for example, engaging a threaded connection between the first terminal131and the second terminal132, is simplified, and a process of installing the first terminal assembly130on the cap plate20is facilitated, thereby improving productivity of manufacturing the rechargeable battery200.

In this embodiment, the rechargeable battery200may also include a second terminal assembly40electrically connected to the second electrode12and having the same configuration as the first terminal assembly130according to the present embodiment of the present invention or the first terminal assembly30according to the first embodiment.

FIG. 6shows an exploded perspective view of a rechargeable battery according to a third embodiment of the present invention, andFIG. 7shows a partial cross-sectional view of the rechargeable battery according to the third embodiment of the present invention.

Referring to the embodiments shown inFIGS. 6 and 7, the rechargeable battery300according to these embodiments has the same configuration as the rechargeable battery100according to the first embodiment, except a first terminal assembly230. Therefore, no detailed description of the same configurations as in the rechargeable battery100according to the first embodiment will be provided.

The first terminal assembly230according to these embodiments includes a first bottom terminal231(hereinafter, “first terminal”), a first top terminal232(hereinafter, “second terminal”), a first terminal plate233, a first terminal insulating member234, a first gasket235between the first terminal231and the cap plate20, and a corrosion preventing member236. The first terminal assembly230according to these embodiments has the same configuration as the first terminal assembly30according to the first embodiment, except for the corrosion preventing member236. Therefore, no detailed description of the same configurations of the first terminal assembly30according to the first embodiment will be provided.

Further, the first terminal231and the second terminal232according to these embodiments have the same configurations the first terminal31and the second terminal32according to the first embodiment, except that the first terminal231and the second terminal232may be made of different materials, for example different types of metal. Therefore, no detailed description on the same configuration of the first terminal31and the second terminal32according to the first embodiment will be provided.

The first terminal231and the first current collector50according to these embodiments may made from the same material, for example the same type of metal, and the second terminal232and the first terminal plate233may be made from the same material, for example the same type of metal. For example, the first terminal231and the first current collector50according an embodiment can be made of copper, and the second terminal232and first terminal plate233can be made of aluminum.

The first terminal231of the first terminal assembly230according to an embodiment includes a first terminal column231ahaving a first fixed groove231a1, and a first terminal flange231bprotruding from an end of the first terminal column231a.

The second terminal232of the first terminal assembly230according to this embodiment extends from a second terminal head232aand includes a second terminal column232bhaving a second fixed protrusion232b1.

The corrosion preventing member236according to an embodiment, is made of an insulation material, and is positioned between the first fixed groove231alof the first terminal231and the second fixed protrusion232b1of the second terminal column232b. When the corrosion preventing member236is inserted into the first fixed groove231a1according to this embodiment, the second terminal column232bcan be coupled to the corrosion preventing member236and can be fixed thereto. Therefore, the corrosion preventing member236according to this embodiment is installed between the first fixed groove231a1and the second fixed protrusion232b1preventing generation of corrosion at a location where the first terminal231and the second terminal232, which may be made of different types of material, contact each other.

Further, by controlling a torque force or rotation of the second terminal232according to the present embodiment, a torque or rotation of the coupled second terminal232and first terminal231can be controlled, and thus a compression rate of the first gasket235positioned between the first terminal231and the cap plate20is also controlled such that the first gasket235can be adequately sealed.

Further, in the embodiments where the first terminal231and the second terminal232that are made of different types of metal are coupled using a connection such as a threaded connection rather than a friction weld, for example, coupling the first terminal assembly230is facilitated, and productivity of manufacturing the rechargeable battery300is improved.

Further, in embodiments where the second terminal232and the first terminal plate233of the first terminal assembly230are made from the same material, the second terminal232may be fixed to the first terminal231and the second terminal head232aof the second terminal232may be coupled to the first terminal plate233through laser welding thereby fixing the first terminal assembly230to the cap plate20in a stable manner.

In addition, the first terminal231and the second terminal232of the first terminal assembly230of the present invention can have other configurations as well as those embodiments described above. For example, according to another variation of the present exemplary embodiment, the first terminal assembly may include a first terminal including a first terminal column having a first fixed protrusion, and a second terminal including a second terminal column having a second fixed groove to which the first fixed protrusion of the first terminal and the corrosion preventing member are coupled.

In addition, the second terminal assembly according to the present embodiment is not restricted to having the same configuration as the first terminal assembly30according to the first embodiment, and it can have the same configuration as the first terminal assembly130according to the second embodiment.

While this invention has been described in connection with several embodiments described above, it is to be understood that the invention is not limited to these disclosed embodiments, but is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the invention as a whole.