Battery module having holder

A battery module according to an exemplary embodiment of the present invention includes a plurality of rechargeable batteries having a terminal, a holder combined to end portions of the rechargeable batteries and having a first fastening portion, and a bus bar combined to the terminal, electrically connecting the rechargeable batteries, and having a second fastening portion to be fitted into the first fastening portion.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to and the benefit of Korean Patent Application No. 10-2013-0112752 filed in the Korean Intellectual Property Office on Sep. 23, 2013, the entire contents of which are incorporated herein by reference.

BACKGROUND

Field

The described technology relates generally to a battery module. More particularly, the described technology relates generally to a battery module having an improved holder structure to support rechargeable batteries.

Description of the Related Technology

A rechargeable battery differs from a primary battery in that it can be repeatedly charged and discharged, while the latter is incapable of being recharged.

A low-capacity rechargeable battery is used in small portable electronic devices such as mobile phones, notebook computers, and camcorders, while a high-capacity rechargeable battery can be widely used as a power source for driving a motor of a hybrid vehicle, an electric vehicle, and the like.

In addition, a high-capacity battery module normally includes a plurality of rechargeable batteries connected in series, and a rechargeable battery may be formed in a cylindrical or prismatic shape.

The battery module is provided with a bus bar to electrically connect rechargeable batteries.

The bus bar is welded to a terminal of the rechargeable batteries, and welding is performed while the bus bar is aligned above the rechargeable batteries.

A jig and the like are used to locate the bus bar at a correct position, but this kind of work consumes a lot of time and involves complex manufacturing processes.

In addition, locating the bus bar at a correct position is very difficult even if the jig is used.

When external impacts or vibrations are delivered to the battery module, electrical contact failure between the bus bar and the terminal may occur.

If contact failure occurs between the bus bar and the terminal, output power not only decreases as resistance increases, but also heat is generated, thereby resulting in performance deterioration and a shortened life expectancy of the rechargeable battery.

SUMMARY OF CERTAIN INVENTIVE ASPECTS

Accordingly, the present invention has been made in an effort to solve the problem described above, thus the purpose of the present invention is to provide a battery module which can easily and correctly align a bus bar.

Another purpose of the present invention is to provide the battery module which can prevent contact failure between a bus bar and a terminal.

The battery module according to an exemplary embodiment includes a plurality of rechargeable batteries having a terminal and edge portions, a holder combined to end portions of the rechargeable batteries and provided with a first fastening portion, and a bus bar bonded to the terminal, electrically connecting the rechargeable batteries, and having a second fastening portion to be connected with the first fastening portion.

The first fastening portion may be fitted into the second fastening portion, and may be provided with a supporting protrusion formed in the holder, while the second fastening portion may be provided with a supporting hole which is formed in the bus bar and fitted into the supporting protrusion.

The first fastening portion may be provided with a supporting groove, the second fastening portion may be provided with a supporting protrusion which is formed in the bus bar and fitted into the supporting groove, a protecting member covering the bus bar is provided therein, and the bus bar may be disposed between the protecting member and the holder. The protecting member may be formed with a third fastening portion to be fitted into the first fastening portion, and may be provided with tape attached to the bus bar.

The holder may be provided with a first hole into which an end portion of one rechargeable battery is inserted, a second hole into which an end portion of another rechargeable battery neighboring the first one is inserted, and an upper plate partially covering the first and second holes, and the upper plate may be provided with the first fastening portion.

The first fastening portion may be provided with a supporting rib protruding from the holder, and the second fastening portion may be provided with a cut-out portion which is formed in the bus bar and fitted into the supporting rib.

The upper plate may be provided with a mounting groove connected to the first and second holes, the bus bar includes first and second connection portions and the connecting portion disposed between the first and second connection portions, and the mounting groove may be inserted with the first connection portion, the second connection portion, and the connecting portion.

Two first connection portions disposed apart from each other are formed to be connected at one end portion of the connecting portion, two second connection portions disposed apart from each other are formed to be connected at the opposite end portion of the connecting portion, and the two first connection portions may be welded to one rechargeable battery and the two second connection portions may be welded to another rechargeable battery neighboring the first one.

The bus bar includes a first supporting portion protruding from the first connection portion, formed in a curved shape, and contacting the upper plate, and the first supporting portion may be provided with the second fastening portion.

The bus bar is provided with a second supporting portion protruding from the second connection portion, formed in a curved shape, and contacting the upper plate, the second supporting portion may be provided with the second fastening portion, and the first and second connection portions may be provided with a bonding protrusion protruding towards the rechargeable battery and being welded thereto.

According to the present invention, since the holder and the bus bar are combined together, the bus bar can be easily and correctly disposed at a predetermined position, and contact between the bus bar and the terminal can be favorably maintained by preventing the bus bar from being shaken.

DETAILED DESCRIPTION OF CERTAIN INVENTIVE EMBODIMENTS

The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown.

Like reference numerals designate like elements throughout the specification and the drawings.

FIG. 1is a perspective view of a battery module according to a first exemplary embodiment of the present invention, andFIG. 2is an exploded perspective view of the battery module according to the first exemplary embodiment of the present invention.

Referring toFIG. 1andFIG. 2, the battery module100includes a plurality of rechargeable batteries10, a holder20to fix the rechargeable batteries10, and a bus bar30electrically connecting the rechargeable batteries10.

The rechargeable battery10is formed in a cylindrical shape, and includes a case, an electrode assembly inserted into the case and having a positive electrode and a negative electrode, a cap plate combined to an opening of the case, and a terminal protruding out of the case.

The rechargeable battery according to the present exemplary embodiment is exemplarily illustrated as a cylindrical lithium ion rechargeable battery, but the present invention is not limited thereto, and it may be formed in a prismatic shape or any other shapes.

The rechargeable battery10is connected in series with a neighboring rechargeable battery10through the bus bar30.

However, the present invention is not limited thereto, and the rechargeable batteries can be freely connected in series or in parallel.

The rechargeable batteries10formed in a cylindrical shape are disposed with their top and bottom sides alternately arranged.

A positive terminal12is disposed at an end portion of the rechargeable battery10in a height direction thereof, while a negative terminal13is disposed at the opposite end of the rechargeable battery10in a height direction thereof.

One rechargeable battery10is disposed with its positive terminal located at an upper portion, and another rechargeable battery10is disposed with its negative terminal located at an upper portion.

The holder20is combined to one end portion of the rechargeable batteries10in a length direction thereof such that it is combined to different end portions of neighboring rechargeable batteries10in a length direction thereof.

That is, the holder20is combined to an end portion of the rechargeable battery10at one side where the positive terminal12is located, and is combined to an opposite end portion of the neighboring rechargeable battery10where the negative terminal13is located.

As shown, for example, inFIG. 3, the holder20is formed with a first hole23into which the end portion of one rechargeable battery10is inserted, and a second hole24which is disposed apart from the first hole23and inserted with an end portion of another rechargeable battery10.

In addition, the holder20is formed with an upper plate21partially covering the first and second holes23and24, and a mounting groove25connected to the first and second holes23and24is formed in the upper plate21.

The upper plate21supports the end portions of the rechargeable batteries10by partially covering the first and second holes23and24.

The mounting groove25is formed at an inner side of the upper plate21, and is formed to be stepped towards the rechargeable batteries10.

A plurality of supporting protrusions26protrude from the upper plate21, and the plurality of supporting protrusions26are combined with the bus bar30to form a first fastening portion.

Two supporting protrusions26are formed adjacent to the first hole23in the periphery thereof, and two supporting protrusions26are formed adjacent to the second hole24in the periphery thereof.

Meanwhile, an aligning protrusion27is formed at one end portion of the holder20, and an aligning groove28to be combined with the aligning protrusion27is formed at the opposite end portion of the holder20.

Accordingly, neighboring holders20can be easily aligned by coupling of the aligning protrusion27and the aligning groove28.

FIG. 4is a perspective view of the bus bar of the battery module according to the first exemplary embodiment of the present invention, andFIG. 5is a cross-sectional view ofFIG. 4, taken along the line V-V.

Referring toFIG. 4andFIG. 5, the bus bar30includes first connection portions31connected to the positive terminal12of one rechargeable battery10, second connecting portions32connected to negative terminal13of another rechargeable battery10and a central connecting portion33disposed between the first and second connecting portions31and32.

The bus bar30is made of a conductive metal plate, the first connection portions31are disposed at one end portion of the bus bar30in a length direction thereof, and the second connection portions32are disposed at the opposite end portion of the bus bar30in a length direction thereof.

Thus, the first connection portions31are connected to one end portion of the connecting portion33, the second connection portions32are connected to the opposite end portion of the connecting portion33, and the first and second connection portions31and32are formed to be elongated in respective opposite directions.

The first connection portions31, the second connection portions32, and the connecting portion33are disposed to be inserted into the mounting groove25.

The connecting portion33is formed with two first connection portions31that are elongated, and the two first connection portions31are disposed apart from each other.

The first connection portions31are respectively provided with a bonding protrusion31aprotruding towards the rechargeable battery10, and the bonding protrusion31ais formed in a curved shape.

The bonding protrusion31ais welded to the terminal of the rechargeable battery10such that each bonding protrusion31aformed in the first connection portion31is welded to the terminal of one rechargeable battery10.

In the present exemplary embodiment, when the two first connection portions31disposed apart from each other in the rechargeable battery10are bonded together, the second connection portions32individually move with elasticity, thereby absorbing or buffering external vibrations.

The battery module100may be applied to a power tool, a vehicle, and the like, which generate repeated vibrations.

These vibrations may cause contact failure at the welded part of the first connection portion31and the terminal.

This can cause a critical durability problem of the battery module100, but the first connection portions31according to the present exemplary embodiment serve to buffer vibrations, thereby reducing the problem of contact failure.

First supporting portions34are respectively formed to protrude outwards from the first connection portions31. The first supporting portions34are bent at the first connection portion31and are disposed above the first connection portion31, and the first supporting portion34contacts the upper plate21. The first supporting portions34are formed with supporting holes34ato be fitted into the supporting protrusion26, and the second fastening portion is provided with the supporting holes34a.

Two second connection portions32are formed to be elongated in the connecting portion33, and the two second connection portions32are disposed apart from each other.

The second connection portions32are respectively formed with a bonding protrusion32a, and the bonding protrusions32aare formed in a curved shape.

The bonding protrusions32aare welded to the terminal of the rechargeable battery10, and each bonding protrusion32ais welded to the terminal of one rechargeable battery10.

Second supporting portions35are respectively formed to protrude outwards from the second connection portions32.

The second supporting portions35are bent at the second connection portions32and disposed at a different plane therefrom, are disposed above (refer toFIG. 4) the second connection portions32, and contact the upper plate21.

The second supporting portions35are provided with supporting holes35ato be fitted into the supporting protrusion26, and the second fastening portion is provided with the supporting holes35a.

Meanwhile, a drawn-out terminal36is formed to protrude from a lateral end of the connecting portion33such that it is electrically connected to the neighboring bus bar30or to the terminal installed outside (not shown in FIGS.) and transmits a current.

As shown inFIG. 2, a protecting member50covering the bus bar30is provided above the bus bar30, and the bus bar30is disposed between the protecting member50and the holder20. The protecting member50is formed in a plate shape, and is provided with two openings51and52. The protecting member50is made of a polymer having an electrical insulating property. The protecting member50is formed with supporting holes53, and the third fastening portion is provided with the supporting holes53.

The bus bar30is welded to the rechargeable batteries10while the protecting member50is combined to the holder20, and welding can be easily performed by contacting welding tools with the bus bar30through the openings.

FIG. 6is an exploded perspective view of a holder and a bus bar according to a second exemplary embodiment of the present invention.

Referring toFIG. 6, since a battery module according to the present exemplary embodiment has the same structure as the battery module according to the first exemplary embodiment, except for a holder60, a bus bar70, and a protecting member80, a repeated description of the same structure will be omitted.

The holder60is combined to one end portion of the rechargeable batteries10in a length direction thereof such that it is provided with a first hole63into which an end portion of one rechargeable battery10is inserted and a second hole64disposed apart from the first hole63and inserted with an end portion of another rechargeable battery10.

In addition, the holder60is formed with an upper plate61partially covering the first and second holes63and64, and a mounting groove65connected to the first and second holes63and64is formed in the upper plate61.

The upper plate61is formed with a plurality of supporting grooves66, and the plurality of supporting grooves66are combined with the bus bar70to form a first fastening portion.

Meanwhile, an aligning protrusion67is formed at one end portion of the holder60, and an aligning groove68to be combined with the aligning protrusion67is formed at the opposite end portion of the holder60.

The bus bar70includes first connection portions71connected to the terminal of one rechargeable battery10, second connection portions72connected to the terminal of another rechargeable battery10, and a connecting portion73disposed between the first and second connection portions71and72.

The first connection portions71are connected to one end portion of the connecting portion73, the second connection portions72are connected to the opposite end portion of the connecting portion73, and the first and second connection portions71and72are respectively formed to be elongated in respective opposite directions.

The first connection portions71, the second connection portions72, and the connecting portion73are disposed to be inserted into the mounting groove65.

The first connection portions71are respectively provided with a bonding protrusion71aprotruding towards the rechargeable batteries10, and the bonding protrusion71ais formed in a curved shape.

First supporting portions74are respectively formed to protrude outwards from the first connection portions71.

The first supporting portions74are bent at the first connection portions71and are disposed above the first connection portion71, and the first supporting portions74contact the upper plate71.

The first supporting portions74are formed with supporting protrusions74ato be fitted into the supporting groove66, and a second fastening portion is provided with the supporting protrusion74a.

Second supporting portions75are respectively formed to protrude outwards from the second connection portions72.

The second supporting portions75are bent at the second connection portion72and disposed at a different plane therefrom, are disposed above the second connection portion72, and contact the upper plate61.

The second supporting portions75are provided with supporting protrusions75ato be fitted into the supporting groove66, and the second fastening portion is provided with the supporting protrusion75a.

A drawn-out terminal76is formed to protrude from a lateral end of the connecting portion73such that it is electrically connected to a neighboring bus bar70or to the terminal installed (not shown in FIGS.) and transmits a current.

The protection member80covering the bus bar70is provided above the bus bar70, and the bus bar70is disposed between the protecting member80and the holder60. The protecting member80is formed of tape with one side having an adhesive layer, and is bonded to the bus bar70. Two openings81and82are formed in the protecting member80so as to weld the bus bar70and the rechargeable battery10.FIG. 7is an exploded perspective view of a holder and a bus bar according to a third exemplary embodiment of the present invention.

Referring toFIG. 7, since a battery module according to the present exemplary embodiment has the same structure as the battery module according to the first exemplary embodiment, except for a holder120, a bus bar130, and a protecting member140, a repeated description of the same structure will be omitted.

The holder120is combined to one end portion of one rechargeable battery10in a length direction thereof such that it is provided with a first hole123into which an end portion of one rechargeable battery10is inserted and a second hole124disposed apart from the first hole123and inserted with an end portion of another rechargeable battery.

In addition, the holder120is formed with an upper plate121partially covering the first and second holes123and124, and a mounting groove125connected to the first and second holes123and124is formed in the upper plate121.

The upper plate121is formed with a plurality of supporting ribs126, and the plurality of supporting ribs126are combined with the bus bar130to form a first fastening portion.

The upper plate121is formed with two supporting ribs126.

One supporting rib126is formed close to the first hole123, and is formed to be elongated towards the first hole123from a lateral end of the holder120.

Another supporting rib126is formed close to the second hole124, and is formed to be elongated towards the second hole123from a lateral end of the holder120.

An aligning protrusion127is formed at one end portion of the holder120, and an aligning groove128to be combined with the aligning protrusion127is formed at the opposite end portion of the holder120. The bus bar130includes first connection portions131connected to the terminal of one rechargeable battery10, second connection portions132connected to the terminal of another rechargeable battery10, and a connecting portion133disposed between the first and second connection portions131and132.

The first connection portions131are connected to one end portion of the connecting portion133, the second connection portions132are connected to the opposite end portion of the connecting portion133, and the first and second connection portions131and132are respectively formed to be elongated in respective opposite directions.

The first connection portions131, the second connection portions132, and the connecting portion133are disposed to be inserted into the mounting groove125. The first connection portions131are respectively provided with a bonding protrusion131aprotruding towards the rechargeable battery10, and the bonding protrusions131aare formed in a curved shape. First supporting portions134and134′ are respectively formed to protrude outwards from the first connection portions131. The first supporting portions134and134′ are bent at the first connection portions131and are disposed above the first connection portion131, and the first supporting portions134and134′ contact the upper plate131.

The first supporting portion134is formed with a cut-out portion134ato be fitted into the supporting rib126, and the second fastening portion is provided with the cut-out portion134a.

Second supporting portions135and135′ are respectively formed to protrude outwards from the second connection portions132.

The second supporting portions135and135′ are bent at the second connection portion132and disposed at a different plane therefrom such that they are disposed above the second connection portions132and contact the upper plate131.

The second supporting portions135are provided with a cut-out portion135ato be fitted into the supporting rib126, and the second fastening portion is provided with the cut-out portion135a.

The cut-out portion134ais formed to be elongated inwards from a lateral end of the first supporting portion134, and the cut-out portion135ais formed to be elongated inwards from a lateral end of the second supporting portion135.

A drawn-out terminal136is formed to protrude from a lateral end of the connecting portion133that it is electrically connected to a neighboring bus bar130or to the terminal provided outside (not shown in FIGS.) and transmits a current.

The protection member140covering the bus bar130is provided on the bus bar130, and the bus bar130is disposed between the protecting member140and the holder120. The protecting member140is made of a plate having an electrical insulating property. The protecting member140is provided with two openings141and142to weld the bus bar130and the rechargeable battery10. The protecting member140is formed with a cut-out portion143, and a third fastening portion is provided with the cut-out portion143.