Fuse unit for rechargeable battery with supporting member

A rechargeable battery including: an electrode assembly; a case having an opening to receive the electrode assembly; a cap plate covering the opening of the case; a terminal arranged at the cap plate and electrically connected to the electrode assembly; a current collecting member coupled to the electrode assembly and the terminal and including a fuse unit; and a supporting member coupled to the current collecting member and supporting the fuse unit.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2011-0129665, filed on Dec. 6, 2011 in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference.

BACKGROUND

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

2. Description of the Related Art

A rechargeable battery is a battery that can be recharged and discharged, 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 rechargeable battery may be used as a power supply for driving a motor of an electric vehicle, a hybrid vehicle, or the like, or as a large-capacity power storage device.

Recently, a high-output rechargeable battery using a non-aqueous electrolyte solution of high energy density has been developed. The high-output rechargeable battery is configured as a large-capacity battery module in which a plurality of rechargeable batteries are connected to each other in series, such that the high-output rechargeable battery may be used to drive a motor of a device requiring a large amount of power, such as an electric vehicle, a hybrid vehicle, or the like. The rechargeable battery may have a cylindrical shape, a rectangular shape, or the like.

In the rechargeable battery using a non-aqueous electrolyte solution, an abnormal current may be generated inside the rechargeable battery during a time that the charge and the discharge are repeated such that the rechargeable battery may explode.

Accordingly, to prevent the explosion of the rechargeable battery by the abnormal current, a positive electrode and a negative electrode may be shorted or a fuse unit including a fuse hole may be installed to a current collecting member electrically connecting the terminal and the electrode assembly to prevent or substantially prevent a flow of the current.

However, the fuse unit of the current collecting member including the fuse hole has a smaller cross-sectional area compared with other current collecting members without the fuse hole. Accordingly, a portion formed with the fuse unit of the current collecting member may be more easily damaged by an external impact.

Also, an arc may be generated at the fuse unit by a remaining current after the fuse unit is partially melted by the abnormal current.

SUMMARY

According to an aspect of embodiments of the present invention, a rechargeable battery is configured to prevent or substantially prevent damage to a current collecting member formed with a fuse unit by an external impact. According to another aspect of embodiments of the present invention, a rechargeable battery includes a supporting member which improves durability.

According to another aspect of embodiments of the present invention, a rechargeable battery is configured to prevent or substantially prevent generation of an arc by a remaining current or stress after the fuse unit formed at the current collecting member is partially melted.

A rechargeable battery according to an exemplary embodiment of the present invention includes: an electrode assembly; a case having an opening to receive the electrode assembly; a cap plate covering the opening of the case; a terminal arranged at the cap plate and electrically connected to the electrode assembly; a current collecting member coupled to the electrode assembly and the terminal and including a fuse unit; and a supporting member coupled to the current collecting member and supporting the fuse unit.

In one embodiment, the current collecting member may include a terminal coupling unit coupled to the terminal, and an electrode assembly coupling unit coupled to the electrode assembly, the terminal coupling unit may include the fuse unit, and the supporting member may be coupled to the terminal coupling unit thereby supporting the fuse unit.

A cross-sectional area of the fuse unit may be less than that of other portions of the terminal coupling unit.

The fuse unit may have an opening formed therein.

The supporting member may include a supporting protrusion inserted in the opening.

The supporting protrusion may include an insulating material.

The supporting protrusion may include a high-resistance material.

The rechargeable battery may further include a supporting cap coupled to the supporting member and supporting the fuse unit.

The supporting cap may include a body unit and a coupling groove formed in the body unit, and the supporting member may be coupled to the supporting cap in the coupling groove.

The fuse unit may have an opening formed therein, and the supporting cap may include a coupling protrusion inserted in the opening.

The supporting cap may include an insulating material.

The supporting cap may include a high-resistance material.

The rechargeable battery may further include a lower insulating member between the cap plate and the current collector. The lower insulating member may include a protrusion inserted in an opening of the fuse unit.

The rechargeable battery may be adapted for use as a motor-driving power source for propelling an electric vehicle or a hybrid electric vehicle.

According to an aspect of embodiments of the present invention, the current collector formed with the fuse unit may be stably supported by the supporting member. As such, a rechargeable battery according to embodiments of the present invention is particularly suited for application in an electric vehicle or a hybrid electric vehicle.

According to another aspect of embodiments of the present invention, an arc generated by a remaining current after the fuse unit is melted or partially melted may be prevented or substantially prevented.

DETAILED DESCRIPTION

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

Referring toFIG. 1andFIG. 2, a rechargeable battery100according to an exemplary embodiment of the present invention includes an electrode assembly10, a case26, a first terminal unit30, a second terminal unit40, a cap plate20, first and second lower insulating members60and80, first and second current collecting members50and70, and a supporting member90.

The rechargeable battery100according to one embodiment may be a lithium ion rechargeable battery. Also, a rectangular rechargeable battery is described herein by way of example. However, the present invention is not limited thereto, and may be applied to another rechargeable battery, such as a lithium polymer battery or other battery, as well as to a battery other than a rectangular rechargeable battery.

The electrode assembly10, in one embodiment, may be formed as a jelly roll type by spirally winding a first electrode11and a second electrode12with a separator13interposed therebetween.

In one embodiment, the first electrode11may be formed as a negative electrode, and the second electrode12may be formed as a positive electrode. However, in another embodiment, the first electrode11may be formed as a positive electrode, and the second electrode12may be formed as a negative electrode. However, for purposes of description herein, they will be described as the first electrode11and the second electrode12.

In one embodiment, the first electrode11and the second electrode12may respectively include first and second current collectors formed as a thin metal foil with an active material coated on a surface of the respective current collector.

In one embodiment, the first electrode11and the second electrode12may include a coated part on which the active material is coated on the respective current collector, and a first electrode uncoated region11aand a second electrode uncoated region12aon which the active material is not coated on the respective current collector.

The coated parts form a substantial portion of the first electrode11and the second electrode12in the electrode assembly10, and the first electrode uncoated region11aand the second uncoated region12aare disposed at respective sides of the coated parts in the jelly roll state.

However, the present invention is not limited thereto. For example, in another embodiment, the electrode assembly10may have a structure in which the first electrode11and the second electrode12formed of a plurality of sheets are stacked, having the separator13therebetween.

As shown inFIG. 2, the first electrode uncoated region11aof the electrode assembly10is electrically connected to the first terminal unit30via the first current collecting member50, and the second electrode uncoated region12ais electrically connected to the second terminal unit40via the second current collecting member70.

In one embodiment, the first current collecting member50may include a first electrode coupling unit51coupled with the first electrode11, and a first terminal coupling unit52coupled with a first rivet31of the first terminal unit30.

The case26, according to one embodiment, has a generally rectangular parallelepiped shape and includes an opening formed at one end thereof. However, the present invention is not limited thereto, and in other embodiments, the case may have any of various shapes, such as a cylindrical shape, a pouch shape, or any other suitable shape.

In one embodiment, the cap plate20may include an electrolyte injection opening21, a sealing cap22sealing the electrolyte injection opening21, and a vent hole23installed with a vent plate24.

The cap plate20, in one embodiment, is made of a thin plate and is coupled with the opening of the case26such that the opening is closed and sealed. The electrolyte solution may be inserted inside the closed and sealed case26through the electrolyte injection opening21, and the vent plate24may be configured to be broken when an internal pressure of the case26is greater than a certain pressure (e.g., a predetermined value).

In one embodiment, the first and second terminal units30and40may respectively include first and second rivets31and41, first and the second terminal plates32and42, first and second terminal insulating members33and43installed between the first and second terminal plates32and42and the cap plate20, and first and second gaskets34and44.

The first and second terminal units30and40may include a terminal (not shown) made of a circular cylindrical shape rather than a terminal of a plate type.

The first and second lower insulating members60and80may be positioned and installed adjacent to the cap plate20inside the case26.

The supporting member90according to one embodiment is coupled with the first current collecting member50to support the first current collecting member50.

In one embodiment, structures of the first and second terminal units30and40, structures of the first and second current collecting members50and70, and structures of the first and second lower insulating members60and80are the same or similar, and, therefore, descriptions of the second terminal unit40, the second current collecting member70, and the second lower insulating member80are omitted.

FIG. 3is an exploded perspective view of a portion of the rechargeable battery100, andFIG. 4is a partial cross-sectional view of the rechargeable battery100.

Referring toFIG. 3andFIG. 4, the first rivet31, according to one embodiment, may include a column31a, a flange31b, a first coupling protrusion31c, and a second coupling protrusion31d.

The first current collecting member50, in one embodiment, includes the first electrode coupling unit51coupled with the first electrode11, and the first terminal coupling unit52coupled with the first rivet31.

The first terminal coupling unit52of the first current collecting member50may include a fuse unit including a first coupling groove521, a second coupling groove522, and a fuse hole523. A cross-sectional area of the fuse unit where the fuse hole523is formed is smaller than that of other portions of the first terminal coupling unit52. That is, in one embodiment, the first terminal coupling unit has a smallest cross-sectional area and greatest resistance at the fuse unit where the fuse hole523is formed, and is configured to melt at the portion of the fuse unit where the fuse hole523is formed under an abnormal current condition.

The first lower insulating member60, in one embodiment, includes a first current collecting member coupling unit61, fixing protrusions62and64, a flange fixing groove63, a protrusion65formed at the first current collecting member coupling unit61, and a through-hole66.

The supporting member90, in one embodiment, includes a first fixing groove91, a second fixing groove92, and a supporting protrusion93.

According to one embodiment, the column31aof the first rivet31is inserted into the through-hole66formed at the first lower insulating member60, and the first flange31bmay be fixed to the flange fixing groove63formed at the first lower insulating member60.

In one embodiment, the column31aof the first rivet31is rivet-coupled with the first terminal plate32and coupled with the cap plate20to be fixed such that the first lower insulating member60is coupled with the first rivet31to be fixed inside the case26.

The first terminal coupling unit52of the first current collecting member50is inserted into the first current collecting member coupling unit61, and the first coupling groove521of the first terminal coupling unit52may be coupled with the first coupling protrusion31cformed at the first rivet31.

In one embodiment, the second coupling groove522is coupled with the second coupling protrusion31dof the first rivet31, and the protrusion65formed at the first lower insulating member60is inserted in the fuse hole523formed at the first terminal coupling unit52.

In one embodiment, the first coupling protrusion31cand the first coupling groove521, and the second coupling protrusion31dand the second coupling groove522, may be adhered by welding, or may be coupled by a friction-fit or press-fit.

The supporting member90according to one embodiment may be inserted into the first current collecting member coupling unit61of the first lower insulating member60.

The first coupling protrusion31cof the first rivet31is coupled to the first fixing groove91of the supporting member90, and the second coupling protrusion31dof the first rivet31may be coupled to the second fixing groove92.

The supporting protrusion93of the supporting member90may be inserted into the fuse hole523of the first current collecting member50.

Accordingly, the supporting member90according to an exemplary embodiment of the present invention is coupled with the first terminal coupling unit52of the first current collecting member50via the first rivet31, thereby supporting the first current collecting member50.

In one embodiment, the supporting protrusion93of the supporting member90is inserted into the fuse hole523formed at the first terminal coupling unit52such that the mechanical strength of a portion of the fuse unit of the first current collecting member50where the fuse hole523is formed may be reinforced.

Accordingly, the first current collecting member50formed with the fuse hole523may be stably fixed inside the case26, and damage to the first current collecting member50(e.g., to the fuse unit where the fuse hole523is formed) by an external impact may be prevented or substantially prevented. As such, a rechargeable battery according to embodiments of the present invention is particularly suited for application in an electric vehicle or a hybrid electric vehicle.

According to an exemplary embodiment of the present invention, at least one of the supporting member90and the supporting protrusion93of the supporting member90is made of an insulating material.

Accordingly, a distance between fractured or broken surfaces of the fuse unit after an abnormal current is generated under the charge or discharge of the rechargeable battery100such that the circumference of the fuse hole523of the first current collecting member50is melted may be great enough because of the supporting protrusion93of the supporting member90such that the current does not flow.

Further, according to an exemplary embodiment, the supporting protrusion93of the supporting member90may be made of a high-resistance material in which only a current greater than a certain current (e.g. a critical current) will flow.

Accordingly, a current that may otherwise generate an arc between the fractured or broken surfaces after the abnormal current is generated under the charge or the discharge of the rechargeable battery100such that the fuse unit of the first current collecting member50where the fuse hole523is formed is melted may flow through the supporting protrusion93of the supporting member90, and thereby an arc being generated between the fractured surfaces may be prevented or substantially prevented.

FIG. 5is an exploded perspective view of a portion of a rechargeable battery according to another exemplary embodiment of the present invention, andFIG. 6is a partial cross-sectional view of the rechargeable battery ofFIG. 5.

Referring toFIG. 5andFIG. 6, a rechargeable battery200according to another exemplary embodiment is the same or substantially the same as the rechargeable battery100described above, except for a supporting member90aand a supporting cap90b, and further description of the same structures is therefore omitted.

According to another exemplary embodiment, the supporting member90amay include a first fixing groove91acoupled to the first coupling protrusion31cof the first rivet31, and a second fixing groove92acoupled to the second coupling protrusion31dof the first rivet31.

Also, a curved or offset portion93amay be formed at one end of the supporting member90aat a location corresponding to an end of the first current collecting member50having the fuse hole523formed therein.

The supporting cap90b, according to one embodiment, is coupled to the end of the supporting member90ahaving the curved portion93ato support the fuse unit formed with the fuse hole523.

In one embodiment, the supporting cap90bincludes a body unit91band a coupling groove92b.

As shown inFIG. 5andFIG. 6, the curved portion93aformed at one end of the supporting member90amay be inserted into the coupling groove92bto be fixed to the supporting cap90b.

Accordingly, the circumference of the fuse portion formed with the fuse hole523and the first current collecting member50may be supported by the supporting member90acoupled with the supporting cap90bsuch that the mechanical rigidity and strength of the first current collecting member50may be reinforced.

In one embodiment, the supporting cap90bmay be made of a high-resistance material through which only a current greater than a certain current (e.g., a critical current) will flow.

Accordingly, a current that may otherwise generate an arc between the fractured or broken surfaces after the abnormal current is generated under the charge or the discharge of the rechargeable battery200such that the fuse unit of the first current collecting member50where the fuse hole523is formed is melted may flow through the supporting cap90b, and thereby an arc being generated between the fractured surfaces may be prevented or substantially prevented.

FIG. 7is an exploded perspective view of a rechargeable battery according to another exemplary embodiment of the present invention, andFIG. 8is a partial cross-sectional view of the rechargeable battery ofFIG. 7.

Referring toFIG. 7andFIG. 8, a rechargeable battery300according to another exemplary embodiment is the same or substantially the same as the rechargeable battery200described above except for a supporting cap90c, and further description of the same structures is therefore omitted.

The supporting cap90caccording to another exemplary embodiment includes a body unit91c, a coupling groove92c, and a cap protrusion93c.

The curved or offset portion93aformed at one end of the supporting member90amay be inserted in the coupling groove92c, and the cap protrusion93cmay be inserted in the fuse hole523formed at the first terminal coupling unit52of the first current collecting member50.

Accordingly, the first current collecting member50may be supported by the supporting member90aand the supporting cap90cformed with the cap protrusion93ccoupled with one end of the supporting member90asuch that the mechanical strength of the first current collecting member50may be reinforced.

According to an exemplary embodiment, the supporting cap90cmay be made of an insulating material.

Accordingly, a distance between fractured or broken surfaces of the fuse unit after an abnormal current is generated under the charge or the discharge of the rechargeable battery300such that the fuse unit at the circumference of the fuse hole523of the first current collecting member50is melted may be great enough by the cap protrusion93cof the supporting cap90csuch that the current does not flow.

According to an exemplary embodiment, the supporting cap90cmay be made of a high-resistance material through which only a current greater than a certain current (e.g., a critical current) will flow.

Accordingly, a current that may otherwise generate an arc between the fractured or broken surfaces of the fuse unit after the abnormal current is generated under the charge or the discharge of the rechargeable battery300such that the fuse unit of the first current collecting member50where the fuse hole523is formed is melted may flow through the supporting cap90c, and thereby an arc being generated between the fractured surfaces may be prevented or substantially prevented.