Rechargeable battery having current collector

A rechargeable battery includes: a case having an opening; an electrode assembly in the case and including a first electrode and a second electrode; a cap plate coupled to the opening of the case; a first current collector electrically connected to the first electrode; and a support fixed to an inner surface of the case, wherein the first current collector is hooked on the support.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2015-0085280 filed in the Korean Intellectual Property Office on Jun. 16, 2015, the entire contents of which are incorporated herein by reference.

BACKGROUND

Embodiments of the present invention relate to a rechargeable battery, and more particularly, to a rechargeable battery including a current collector.

2. Description of the Related Art

A rechargeable battery can be repeatedly charged and discharged, unlike a primary battery that is typically not recharged. Low capacity rechargeable batteries are used for small portable electronic devices such as mobile phones, laptop computers, and camcorders and large capacity batteries are widely used as power sources for driving motors of hybrid vehicles, etc.

Nowadays, a high power rechargeable battery using a non-aqueous electrolyte with high energy density has been developed, and the high power rechargeable battery is formed as a large capacity rechargeable battery by connecting a plurality of rechargeable batteries in series to use for driving a motor of a device, for example, an electric vehicle, requiring a large amount of electric power.

Further, a large capacity rechargeable battery is generally formed with a plurality of rechargeable batteries that are connected in series, and a rechargeable battery may be formed in a cylindrical shape or a rectangular shape.

The rechargeable battery includes an electrode assembly for performing charging and discharging operations, a case for accommodating the electrode assembly, and a terminal extending out of the case. The electrode assembly and the terminal are electrically connected to each other via the current collector, which is welded to a lower end of the terminal.

The above information disclosed in this Background section is provided to enhance the understanding of the background of the invention only, and therefore it may contain information that does not form prior art.

SUMMARY

The present invention has been made in an effort to provide a rechargeable battery in which a current collector can easily be coupled to a terminal.

An exemplary embodiment of the present invention provides a rechargeable battery including: a case having an opening; an electrode assembly in the case and including a first electrode and a second electrode; a cap plate coupled to the opening of the case; a first current collector electrically connected to the first electrode; and a support fixed to an inner surface of the case, wherein the first current collector is hooked on the support.

Herein, the support may include a bonding portion bonded to the case, an inclination portion obliquely bent from the bonding portion and extending away from the case, and a support portion bent from the inclination portion, parallel to a second current collector, and bonded to the second current collector.

In addition, the support may include a bonding portion bonded to the case and a support portion vertically bent from the bonding portion and extending toward the electrode assembly.

The support may further include a bonding portion bonded to the case, a support surface by which a second current collector is hooked, and an inclination surface connecting the support surface with the bonding portion.

The first current collector may include a base plate bonded to the electrode assembly and a protrusion extending from the base plate and hooked on the support.

The first current collector may further include a plurality of guide protrusions that separately extend from a front end of the protrusion.

The front end of the protrusion may be positioned on a top surface of the support and a welded portion, to which the protrusion and the support are welded, may be between the guide protrusions.

An exemplary embodiment of the present invention provides a rechargeable battery including: a case having an opening; an electrode assembly in the case and including a first electrode and a second electrode; a cap plate coupled to the opening of the case; a terminal extending through a lateral surface of the case, the terminal being electrically connected to the second electrode; and a second current collector connecting the first electrode with the terminal, the second current collector being hooked on the terminal.

Herein, the second current collector may include a base plate bonded to the electrode assembly, and a protrusion extending from the base plate and hooked on the terminal.

The second current collector may further include a plurality of guide protrusions that separately extend from the protrusion.

The terminal may include a plate terminal outside the case, a pillar terminal extending through the case, and a connection plate fixed to the pillar terminal and having a plate shape.

The connection plate may have a support opening and the pillar terminal may be in the support opening.

The connection plate may be arranged perpendicular to a bottom of the case and the protrusion may be hooked on an upper end of the connection plate.

A support may be fixed to an inner surface of the case and a first current collector may electrically connect the first electrode with the support and the first current collector may be hooked on the support.

The support may include a bonding portion bonded to the case, an inclination portion obliquely bent from the bonding portion and extending away from the case, and a support portion bent from the inclination portion, parallel to the second current collector, and bonded to the second current collector, the protrusion may be supported by a top surface of the support portion.

The support may include a bonding portion bonded to the case and a support portion vertically bent from the bonding portion to extend toward the electrode assembly.

The support may include a bonding portion bonded to the case, a support surface by which the second current collector is hooked, and an inclination surface connecting the support surface with the bonding portion.

According to the exemplary embodiments of the present invention, because the current collector is supported by the terminal or the support, the current collector can easily be coupled to the terminal, and thus the rechargeable battery according to the present exemplary embodiments can improve impact resistance.

DETAILED DESCRIPTION

The embodiments of the present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art would realize, the described embodiments may be modified in various suitable ways, all without departing from the spirit or scope of the present invention. In the drawings and this specification, the same or like constituent elements (or components) are designated by the same reference numerals throughout the specification.

Further, it will also be understood that when one element, component, region, layer and/or section is referred to as being “between” two elements, components, regions, layers, and/or sections, it can be the only element, component, region, layer and/or section between the two elements, components, regions, layers, and/or sections, or one or more intervening elements, components, regions, layers, and/or sections may also be present.

As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Expressions such as “at least one of,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list. Further, the use of “may” when describing embodiments of the present invention refers to “one or more embodiments of the present invention.” Also, the term “exemplary” is intended to refer to an example or illustration.

It will be understood that when an element or layer is referred to as being “on,” “connected to,” “coupled to,” “connected with,” “coupled with,” or “adjacent to” another element or layer, it can be “directly on,” “directly connected to,” “directly coupled to,” “directly connected with,” “directly coupled with,” or “directly adjacent to” the other element or layer, or one or more intervening elements or layers may be present. Further “connection,” “connected,” etc. may also refer to “electrical connection,” “electrically connect,” etc. depending on the context in which they are used as those skilled in the art would appreciate. When an element or layer is referred to as being “directly on,” “directly connected to,” “directly coupled to,” “directly connected with,” “directly coupled with,” or “immediately adjacent to” another element or layer, there are no intervening elements or layers present.

FIG. 1is a perspective view illustrating a rechargeable battery according to a first exemplary embodiment of the present invention, andFIG. 2is a cut-away perspective view of the rechargeable battery according to the first exemplary embodiment of the present invention.

Referring toFIG. 1andFIG. 2, the rechargeable battery101according to the first exemplary embodiment includes an electrode assembly10formed by winding a positive electrode (first electrode)11and a negative electrode (second electrode)12a separator13interposed therebetween, a case21in which the electrode assembly10is mounted, and a cap plate23coupled to an opening212of the case21.

The rechargeable battery101of the present exemplary embodiment is exemplarily illustrated as a lithium ion rechargeable battery formed in the shape of a cuboid. However, the present exemplary embodiment is not limited thereto, and the embodiments of the present invention may be applied to various suitable types of batteries including a lithium polymer battery or a cylindrical battery.

The positive electrode (first electrode)11and the negative electrode (second electrode)12include coated regions where an active material is coated onto a current collector formed of a thin metal foil, and uncoated regions11aand12awhere the active material is not coated. As shown inFIG. 2, the positive electrode uncoated region11ais formed at one end of the electrode assembly10, and is disposed at an upper portion of the electrode assembly10. The negative uncoated region12ais formed at the other side of the electrode assembly10, and is disposed at an upper portion of the electrode assembly10.

The case21has a quadrangular-column shape, and has the opening212formed at an upper end thereof. A step portion214(illustrated inFIG. 5) at which the cap plate23is mounted is formed in the case21. The cap plate23has a long-plate shape, and is in the opening212of the case21and welded to the case21.

A terminal30is in the case and mounted to one of the side surfaces of the case21. Further, a vent opening213is formed at the one of the side surfaces of the case21, and a vent plate26which is opened when a set pressure (e.g., a predetermined pressure) is applied to the vent opening213. A notch26ais formed in the vent plate26.

FIG. 3is a perspective view illustrating an electrode assembly and a current collector according to the first exemplary embodiment of the present invention.

Referring toFIG. 2andFIG. 3, a first current collector51is bonded to the positive electrode uncoated region11a, and a second current collector52is bonded to the negative uncoated region12a. In this case, the first current collector51and the second current collector52may respectively be bonded to the positive electrode uncoated region11aand the negative uncoated region12aby ultrasonic welding.

FIG. 4is a cross-sectional view illustrating a connection structure of a first current collector according to the first exemplary embodiment of the present invention, andFIG. 5is a partially cut-away perspective view of the rechargeable battery according to the first exemplary embodiment of the present invention.

Referring toFIG. 4andFIG. 5, a support24is fixed and mounted to the case21to face the first current collector51. The support24includes a bonding portion241bonded to the case21, an inclination portion243which is obliquely bent from the bonding portion241to extend away from the case21, and a support portion242which is bent from the inclination portion243to be parallel to the first current collector51and bonded to the first current collector51.

The bonding portion241is formed of a plate that is disposed in parallel with an inner surface of the case21, and is welded to the inner surface of the case21. The inclination portion243is obliquely bent from an upper end of the bonding portion241toward the electrode assembly10. The support portion242is bent from the inclination portion243to be parallel to the first current collector51to contact the first current collector51. When the support portion242is formed in parallel with the first current collector51, the support portion242can more securely support the first current collector51.

The first current collector51includes a base plate51a, a protrusion51bextending from the base plate51ato be hooked on the support24, and two guide protrusions51cwhich are separately disposed to extend from the protrusion51b.

The base plate51ahas a quadrangular-plate shape, and is bonded to the positive electrode uncoated region11a. The protrusion51bis bent from an upper end of the base plate51ato extend toward the support24. As described above, the guide protrusions51care separately disposed to extend from a front end of the protrusion51b. The protrusion51bextends and is hooked on an upper end of the support24, and a front end of the protrusion51bis disposed on the support24. The guide protrusion51cextends from the front end of the protrusion51btoward a lateral surface of the lateral surface, and is disposed at an end portion of the protrusion51bin a width direction.

The first current collector51is welded to the upper end of the support24. In this case, the first current collector51is welded to the upper end of the support portion242. A welded portion56is formed at the upper end of the support24to extend in the width direction of the support24. The welded portion56is formed between the guide protrusions51cto contact the front end of the protrusion51b.

When the first current collector51is bonded to the support24, the case21is positively charged. While being fixed to the electrode assembly10, the first current collector51is hooked on the support24before being welded thereto. As such, by allowing the first current collector51to be hooked on the support24, it is possible to more easily weld the first current collector51. Further, it is possible to prevent or substantially prevent the contact between the first current collector51and the support24from deteriorating due to vibration or impact.

FIG. 6is a cross-sectional view illustrating a connection structure of a second current collector according to the first exemplary embodiment of the present invention.

Referring toFIG. 2andFIG. 6, the terminal30, connected to the second current collector52, is mounted to the case21. The terminal30is extends through a lateral surface21bof the case21and is electrically connected to the second electrode12via the second current collector52.

The terminal30includes a plate terminal31disposed outside the case21, a pillar terminal35mounted to the case and extends through the case21, and a connection plate36is fixed to the pillar terminal35and has a plate shape. The pillar terminal35is in the plate terminal31, and is fixed to the plate terminal31by being caulked and welded thereto.

The pillar terminal35includes a first pillar32made of aluminum and a second pillar34bonded to the first pillar32and made of copper. The first pillar32and the second pillar34may be bonded by using friction stir welding. The first pillar32is welded to the plate terminal31made of aluminum and the second pillar34made of copper.

The second pillar34has a bar-like shape, and includes a body342bonded to the first pillar32, a flange341which extends externally and is supported by the inner surface of the case21, and a coupling protrusion345extending from the flange341to be fitted into the connection plate36.

The connection plate36has a quadrangular shape, and is arranged perpendicular to a bottom21aof the case21and is disposed in parallel with the lateral surface21bof the case21. A support opening361, into which the coupling protrusion345is inserted, is formed in the connection plate36, and the connection plate36is welded to the second pillar34in a state in which the coupling protrusion345is inserted therein.

The second current collector52includes a base plate52a, a protrusion52bextending from a front end of the base plate52aand hooked on the terminal30, and two guide protrusions52cwhich are separately disposed to extend from the protrusion52b.

The base plate52ahas a quadrangular shape, and is bonded to the negative uncoated region12a. The base plate52ais disposed in parallel with the connection plate36to contact the connection plate36. The protrusion52bis bent from an upper end of the base plate52ato extend toward the terminal30. As described above, the guide protrusions52care separately disposed to extend from a front end of the protrusion52b. The protrusion52bextends and is hooked on an upper end of the connection plate36, and a front end of the protrusion51bis disposed on the protrusion52b.

The second current collector52is welded to an upper end of the connection plate36. In this case, a front end of the protrusion52bis welded to the connection plate36. A welded portion57is formed at the upper end of the connection plate36to extend in a width direction of the connection plate36, and is formed between the guide protrusions52c.

While being fixed to the electrode assembly10, the second current collector52is hooked on the terminal30to be welded thereto. As such, by allowing the second current collector52to be hooked on the terminal30, it is possible to more easily weld the second current collector52. Further, it is possible to prevent or substantially prevent the contact between the second current collector52and the terminal30from deteriorating due to vibration or impact.

FIG. 7is a cross-sectional view illustrating a portion of a rechargeable battery according to the second exemplary embodiment of the present invention.

Referring toFIG. 7, since the rechargeable battery102according to the second exemplary embodiment has the same or substantially the same structure as that of the rechargeable battery according to the first exemplary embodiment except for a support110, a duplicate description of the same or substantially the same structure may be omitted.

The support110includes a bonding portion112which is welded and fixed to a lateral surface of the case21and a support portion113bent from the bonding portion112to extend toward the electrode assembly10. The bonding portion112has a quadrangular-plate shape, and is welded and fixed to an inner surface of the case21. The support portion113is vertically bent from an upper end of the bonding portion112to extend away from the case21. The first current collector51is welded to the support portion113while being hooked on a top surface of the support portion113.

FIG. 8is a cross-sectional view illustrating a portion of a rechargeable battery according to a third exemplary embodiment of the present invention, andFIG. 9is a cut-away perspective view illustrating a case and a support according to the third exemplary embodiment of the present invention.

Referring toFIG. 8andFIG. 9, since the rechargeable battery103according to the third exemplary embodiment has the same or substantially the same structure as that of the rechargeable battery according to the first exemplary embodiment except for a support120, a duplicate description of the same or substantially the same structure may be omitted.

The support120includes a bonding portion121which is welded and fixed to a lateral surface of the case21, a support surface125extended from the bonding portion121to hook the first current collector51, and an inclination surface123for connecting the bonding portion121with the support surface125.

The support120has a bar-like shape having a triangular cross-section, one surface of which serves as the bonding portion121welded to an inner surface of the case21. The bonding portion121and the support surface125are vertically connected to each other, and the inclination surface123is obliquely connected to the bonding portion121and the support surface125. The first current collector51is welded to the support surface125while being hooked on the support surface125.

DESCRIPTION OF SOME OF THE REFERENCE CHARACTERS