Specification
Title of the invention: Bus bar with current cut-off and battery module including the same
Technical field
[One]
The present invention relates to a bus bar having a current blocking unit and a battery module including the same, and more particularly, to a bus bar capable of effectively securing the safety of a battery module when an overcurrent occurs, and a battery module including the same.
[2]
This application is an application for claiming priority for Korean Patent Application No. 10-2018-0016388 filed on February 09, 2018, and all contents disclosed in the specification and drawings of the application are incorporated herein by reference.
Background
[3]
In recent years, as the demand for portable electronic products such as laptops, video cameras, and portable telephones has rapidly increased, and development of electric vehicles, energy storage batteries, robots, satellites, etc. is in full swing, high-performance secondary batteries capable of repetitive charging and discharging Research on is being actively conducted.
[4]
Currently commercialized secondary batteries include nickel cadmium batteries, nickel hydride batteries, nickel zinc batteries, and lithium secondary batteries, among which lithium secondary batteries have little memory effect compared to nickel-based secondary batteries, so charging and discharging are free. The self-discharge rate is very low and the energy density is high.
[5]
These lithium secondary batteries mainly use lithium-based oxides and carbon materials as a positive electrode active material and a negative electrode active material, respectively. In addition, a lithium secondary battery includes an electrode assembly in which a positive electrode plate and a negative electrode plate to which the positive electrode active material and the negative electrode active material are applied, respectively, are disposed with a separator therebetween, and a case for sealing the electrode assembly together with an electrolyte solution, that is, a battery pouch case material. .
[6]
In general, lithium secondary batteries may be classified into can-type secondary batteries in which an electrode assembly is embedded in a metal can, and pouch-type secondary batteries in which an electrode assembly is embedded in a pouch of an aluminum laminate sheet, depending on the shape of the exterior material.
[7]
In recent years, secondary batteries are widely used not only in small devices such as portable electronic devices, but also in mid- to large-sized devices such as automobiles and power storage devices. When used in such a medium-sized device, a large number of secondary batteries are electrically connected to increase capacity and output. In particular, pouch-type secondary batteries are widely used in such medium-sized devices due to the advantage of easy stacking.
[8]
In addition, in order to electrically connect the secondary battery inside the battery module, electrode leads may be interconnected, and a connection portion may be welded to maintain such a connection state. Furthermore, the battery module may have parallel and/or series electrical connection between secondary cells, and for this purpose, one end of the electrode lead may be contacted and fixed to a bus bar for electrical connection between the secondary cells by welding or the like. .
[9]
In addition, the electrical connection between the secondary batteries is often configured in a manner in which the electrode leads are bonded to the bus bar. At this time, in order to electrically connect the secondary batteries in parallel, electrode leads of the same polarity are connected and bonded to each other, and in order to be electrically connected in series, electrode leads of different polarities are connected and bonded to each other.
[10]
In the prior art, a plate-shaped bus bar was used to electrically connect a plurality of secondary batteries of a battery module. In addition, the bus bar is connected to electrode terminals of a plurality of unit cells and connected to a power cable. Accordingly, the current of the unit cells may be discharged through the bus bar through the power cable, or the unit cells may be charged with current through the bus bar connected to the external power source through the power cable.
[11]
However, when overcurrent occurs in the battery module, thermal runaway or the like may occur in a plurality of secondary batteries, and there is a possibility that the battery module may explode or ignite. Moreover, a current concentration phenomenon may occur in a bus bar connected to an external device, and thus components around the bus bar may be damaged by high heat generated in the bus bar. Therefore, the battery module could be difficult to stably use in a high-capacity electric vehicle.
[12]
Accordingly, in the prior art, when an overcurrent occurs in the battery module, an electrical component is provided that controls power to prevent a problem from occurring in an external device or a battery module. However, in the case of an overload or failure of such an electrical component, there may be a case in which the electrical component cannot function properly. To prepare for this, the battery module of the prior art is provided with a fuse to cut off an electrical connection to the outside separately from the electrical component.
[13]
However, when such a fuse is mounted in the battery module, there is a problem that thermal damage may be applied to components such as a housing around the fuse. Moreover, when such a fuse is mounted on the battery module, it occupies a lot of space, so that the energy density of the battery module may be reduced. In addition, the provision of a separate fuse causes a large increase in the manufacturing cost of the battery module, which is not suitable.
[14]
Therefore, there is a need to develop a technology to increase the stability of the battery module to solve this problem.
Detailed description of the invention
Technical challenge
[15]
Accordingly, the present invention has been invented to solve the above problems, and an object of the present invention is to provide a bus bar that can effectively secure the safety of a battery module when an overcurrent occurs, and a battery module including the same.
[16]
Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by examples of the present invention. In addition, it will be easily understood that the objects and advantages of the present invention can be realized by the means shown in the claims and combinations thereof.
Means of solving the task
[17]
The bus bar according to the present invention for achieving the above object,
[18]
A main body configured to be provided in the battery module, having a first metal, having a stepped structure in which an outer surface of the battery module is inserted in an inward direction is formed on a part, and configured to be electrically connected to one or more secondary batteries;
[19]
A current blocking unit including a second metal having a melting point relatively lower than that of the first metal and inserted into a space formed by inserting the outer surface of the stepped structure inward; And
[20]
It may include a covering member configured to surround at least a portion of an outer surface of the current blocking portion.
[21]
Further, the current blocking unit may be configured to electrically connect the upper and lower walls spaced apart from each other in the interior space of the stepped structure.
[22]
Moreover, the area of ​​the cross section orthogonal to the current flow direction of the stepped portion of the step structure may be less than the area of ​​the cross section orthogonal to the current flow direction of the current blocking portion.
[23]
In addition, the outer surface of the stepped portion of the stepped structure may be positioned to face the inner side of the current blocking portion.
[24]
In addition, an extension may be formed to connect between the upper and lower walls spaced apart from each other in the interior space of the stepped structure and extend to cover the outer surface of the current blocking unit.
[25]
Moreover, at least one or more slits may be formed in the current blocking portion.
[26]
In addition, a perforated outlet may be formed in the covering member so that the inside and the outside communicate with each other.
[27]
In addition, a through hole perforated to communicate the inside and the outside may be formed in the stepped portion of the stepped structure.
[28]
Furthermore, the current blocking portion may have a protruding structure extending from a portion of the stepped portion to penetrate the through hole formed in the stepped portion of the stepped structure.
[29]
Further, the through hole formed in the stepped portion of the stepped structure may be positioned to communicate with the outlet of the covering member.
[30]
Furthermore, the covering member may be a mica sheet.
[31]
In addition, the battery module according to the present invention for achieving the above object,
[32]
A plurality of secondary batteries;
[33]
The bus bar according to claim 1 configured to electrically connect the plurality of secondary batteries to each other, and
[34]
And a bus bar frame comprising an electrically insulating material and configured to mount the bus bar on an outer surface.
[35]
In addition, the battery pack according to the present invention for achieving the above object includes at least one battery module according to the present invention.
[36]
Moreover, a vehicle according to the present invention for achieving the above object includes a battery pack according to the present invention.
Effects of the Invention
[37]
According to an aspect of the present invention, the bus bar may be configured to form a stepped structure of the main body so that when a predetermined or more overcurrent flows through the bus bar, the stepped structure of the main body is melted and cut off due to high resistance heat. The busbar can perform a fuse function due to the stepped structure, thereby increasing the safety of the battery module.
[38]
In addition, according to this aspect of the present invention, the bus bar forms a current blocking unit in the inner space formed by the stepped structure of the main body, so that when overcurrent is energized, the stepped structure of the current blocking unit and the main body is quickly melted and lost. You can, so you can quickly disconnect.
[39]
Moreover, according to one aspect of the present invention, the main body and the current blocking unit are mechanically coupled through rolling, so that the electrical connection between the main unit and the current blocking unit is excellent, as well as excellent bonding properties. It can prevent the durability from becoming weak.
[40]
And, according to one aspect of the present invention, by configuring the thickness or cross-sectional area of ​​the stepped structure of the main body to be less than the thickness or cross-sectional area of ​​the current blocking portion, the resistance can be high in the stepped portion of the stepped structure of the main body, and the thickness to be melted It can be cut reliably and quickly due to its small area. That is, the reliability of the fuse function of the bus bar of the present invention can be greatly increased.
[41]
Further, according to an aspect of the present invention, the covering member covers at least a part of the outer surface of the current blocking unit, so that when overcurrent is applied to the bus bar, high heat generated in the current blocking unit does not damage the components adjacent to the bus bar. Heat can be cut off. In addition, the covering member insulates the current blocking unit, so that when overcurrent is applied to the bus bar, the temperature of the current blocking unit can be rapidly increased. Accordingly, it is possible to increase the reactivity of the bus bar of the present invention to overcurrent, thereby exhibiting a rapid current blocking function.
[42]
In addition, according to another aspect of the present invention, by forming an outlet in the covering member, it is possible to help the molten current blocking portion or the molten stepped portion of the stepped structure of the body portion to be smoothly discharged to the outside through the outlet. Accordingly, the reactivity of the bus bar of the present invention to overcurrent can be further increased, and rapid disconnection can be achieved.
Brief description of the drawing
[43]
The following drawings attached to the present specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of ​​the present invention together with the detailed description of the present invention to be described later, so the present invention is described in such drawings. It is limited to and should not be interpreted.
[44]
1 is a perspective view schematically showing a battery module according to an embodiment of the present invention.
[45]
2 is a perspective view schematically showing a bus bar according to an embodiment of the present invention.
[46]
3 is a side view schematically showing a secondary battery according to an embodiment of the present invention.
[47]
4 is a partial cross-sectional view schematically showing a portion of a bus bar cut along the line A-A' of FIG. 2.
[48]
5 is a partial cross-sectional view schematically showing a portion of a bus bar according to another embodiment of the present invention.
[49]
6 is a front view schematically showing a bus bar according to an embodiment of the present invention.
[50]
7 is a cross-sectional view schematically showing a portion of the bus bar cut along the line B-B' of FIG. 6.
[51]
8 is a front view schematically showing some configurations of a bus bar according to another embodiment of the present invention.
[52]
9 is a cross-sectional view schematically showing a portion of the bus bar cut along the line C-C' of FIG. 8.
[53]
10 is a partial cross-sectional view schematically showing a portion of a bus bar according to another embodiment of the present invention.
[54]
11 is a front view schematically showing some configurations of a bus bar according to another embodiment of the present invention.
[55]
12 is a perspective view schematically showing a battery module according to an embodiment of the present invention.
Mode for carrying out the invention
[56]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as being limited to their usual or dictionary meanings, and the inventors appropriately explain the concept of terms in order to explain their own invention in the best way. Based on the principle that it can be defined, it should be interpreted as a meaning and concept consistent with the technical idea of ​​the present invention.
[57]
Accordingly, the embodiments described in the present specification and the configurations shown in the drawings are only the most preferred embodiments of the present invention, and do not represent all of the technical spirit of the present invention. It should be understood that there may be equivalents and variations.
[58]
[59]
1 is a perspective view schematically showing a battery module according to an embodiment of the present invention. 2 is a perspective view schematically showing a bus bar according to an embodiment of the present invention. 3 is a side view schematically showing a secondary battery according to an embodiment of the present invention. And, FIG. 4 is a partial cross-sectional view schematically showing a portion of the bus bar cut along the line A-A' of FIG. 2.
[60]
1 to 4, a bus bar 240 according to an embodiment of the present invention includes a body portion 241, a current blocking portion 244 (hidden line display), and a covering member 245. . In addition, the battery module according to an embodiment of the present invention may be provided with at least one bus bar to electrically connect a plurality of secondary batteries.
[61]
Here, the main body 241 may include a first metal. The first metal may be a highly electrically conductive material capable of transmitting electricity with less than 40% power loss. For example, the first metal may be copper. However, it is not necessarily limited to copper, and any metal having high electrical conductivity such as copper may be used, and for example, a copper alloy or gold may be used.
[62]
In addition, when viewed from the F direction of FIG. 1, the main body 241 may have a bar shape that is elongated in the vertical direction. Moreover, a stepped structure 242 in which an outer surface in an outer direction is inwardly inserted in the outer direction based on a central portion of the overall shape of the battery module may be formed on a part of the bar-shaped body part 241. Here, the outward direction of the battery module 300 refers to a direction toward the outside relative to the central portion of the battery module 300. Conversely, the inner direction of the battery module 300 refers to a direction toward the center of the battery module from the outside. In some cases, in the present specification,'outside direction' and'inside direction' may be abbreviated to be referred to as'outside' and'inside'.
[63]
That is, the stepped portion 242a of the stepped structure 242 may be configured such that a portion of the body portion 241 has a relatively thinner thickness Z in the front-rear direction than the remaining portions. In the meantime, in the present specification, unless otherwise specified, it is based on the case of looking in the F direction with respect to the up, down, front, back, left, and right directions.
[64]
In addition, in the stepped structure 242, an outer surface of the main body 241 in an outer direction is inserted in an inner direction to form a predetermined space. In addition, the stepped structure 242 may have a structure in which an inner and outer surface of the main body 241 is inserted in an outer direction. That is, the stepped portion 242a of the stepped structure 242 may be a structure formed by being embedded in both the front and rear directions.
[65]
Further, the stepped structure 242 may include an upper wall 242b and a lower wall 242c spaced apart from each other with a predetermined space therebetween. In addition, the stepped structure 242 may have an inner sidewall 242d in an inward direction.
[66]
Accordingly, according to this configuration of the present invention, by forming the stepped structure 242 of the main body 241, when a predetermined or more overcurrent flows through the bus bar 240, the stepped structure of the main body 241 ( Since the 242 may be configured to be melted and disconnected due to high resistance heat (breaking), the bus bar 240 may perform a fuse function due to the stepped structure 242.
[67]
In addition, the main body 241 may be configured to be electrically connected to one or more secondary batteries 100.
[68]
Here, the secondary battery 100 may be a pouch-type secondary battery 100. In particular, such a pouch-type secondary battery 100 may include a pouch 120. In addition, the secondary battery 100 may include an electrode assembly (not shown) and an electrolyte (not shown) accommodated in the pouch 120.
[69]
Here, the pouch 120 may be composed of two pouches, a left pouch and a right pouch in which the concave storage unit 115 is formed. In addition, an electrode assembly and an electrolyte may be accommodated in the receiving part 115. In addition, each pouch includes an outer insulating layer, a metal layer, and an inner adhesive layer, and an inner adhesive layer adheres to each other on an edge portion of the pouch 120, thereby forming a sealing portion. Furthermore, a terrace portion may be formed at both ends of the pouch 120 on which the positive lead 111 and the negative lead 112 are formed.
[70]
In addition, the electrode assembly is an assembly of an electrode and a separator, and may be configured in a form in which at least one positive electrode plate and at least one negative electrode plate are disposed with the separator interposed therebetween. In addition, a positive electrode tab may be provided on the positive electrode plate of the electrode assembly, and one or more positive electrode tabs may be connected to the positive electrode lead 111.
[71]
Here, the positive lead 111 has one end connected to the positive electrode tab and the other end exposed to the outside of the pouch 120, and the exposed part is an electrode terminal of the secondary battery 100, for example, a secondary It can function as a positive terminal of the battery 100.
[72]
In addition, a negative electrode tab may be provided on the negative electrode plate of the electrode assembly, and one or more negative electrode tabs may be connected to the negative electrode lead 112. In addition, the negative lead 112 has one end connected to the negative electrode tab and the other end exposed to the outside of the pouch, and the exposed part is an electrode terminal of the secondary battery 100, for example, the secondary battery 100 Can function as the negative terminal of
[73]
Moreover, the positive electrode lead 111 and the negative electrode lead 112 may be formed at both ends of the secondary battery 100 in opposite directions (forward and backward directions) with respect to the center of the secondary battery 100. That is, the positive electrode lead 111 may be provided at one end with respect to the center of the secondary battery 100. In addition, the negative lead 112 may be provided at the other end of the secondary battery 100 based on the center of the secondary battery 100. For example, as shown in FIGS. 1 and 2, each secondary battery 100 may be configured such that the positive lead 111 and the negative lead 112 protrude forward and backward.
[74]
Accordingly, according to this configuration of the present invention, there is no interference between the positive electrode lead 111 and the negative electrode lead 112 in one secondary battery 100, and the area of ​​the electrode lead 110 can be increased.
[75]
In addition, the positive lead 111 and the negative lead 112 may be formed in a plate shape. In particular, the positive lead 111 and the negative lead 112 may protrude in a horizontal direction with a wide surface erected to face left and right.
[76]
In addition, a plurality of the secondary batteries 100 may be included in the battery module 300 and may be arranged to be stacked in at least one direction. For example, a plurality of pouch-type secondary batteries 100 may be stacked side by side in a horizontal direction.
[77]
At this time, each pouch-type secondary battery 100, when viewed in the F direction (shown in FIG. 1), has two wide surfaces positioned on the left and right sides, and sealing portions are positioned at the top and bottom, front and rear. It can be arranged in a form that stands approximately perpendicular to the ground. In other words, each secondary battery 100 may be configured to be erected in a vertical direction.
[78]
However, the battery module 300 according to the present invention is not limited to the pouch-type secondary battery 100 described above, and various secondary batteries 100 known at the time of filing of the present invention may be employed.
[79]
Meanwhile, the main body 241 may be configured such that the positive electrode lead 111 or the negative electrode lead 112 of the secondary battery 100 is in contact with an outer surface of a portion thereof. In addition, the battery module 300 may further include a connection bus bar 250. Unlike the bus bar 240, the connection bus bar 250 may not have a stepped structure 242 formed thereon. In addition, the connection bus bar 250 may have an insertion hole O1 (shown in FIG. 12) formed so that the positive lead 111 or the negative lead 112 can be inserted.
[80]
For example, as shown in FIG. 1, the battery module 300 may be provided with two bus bars 240 and 240B configured to electrically connect an external device or another battery module. Both of these two busbars 240 and 240B may be provided with a current blocking unit 244, or of these, only one of the busbars 240 may be provided with a current blocking unit 244. In addition, five connection busbars 250 without the current blocking unit 244 may be provided.
[81]
In addition, for example, as shown in FIG. 1, the seven busbars 240, 240B and 250 may be configured to electrically connect 12 secondary batteries 100 in parallel and in series. Furthermore, the five connection busbars 250 may have two positive leads 111, two negative leads 112, or the positive lead 111 and the negative lead 112 in contact. In addition, the positive lead 111 or the negative lead 112 may be in contact with the two bus bars 240 and 240B configured to be electrically connected to an external device or another battery module 300.
[82]
Referring back to FIGS. 2 and 4, the current blocking unit 244 may be inserted into a space formed by inwardly inserting an outer surface of the stepped structure 242 of the main body 241. That is, the current blocking unit 244 may be inserted so that at least a portion of the space is in contact with the inner surface of the stepped structure 242. Alternatively, the current blocking part 244 may be inserted so as to be completely filled in a space formed by being inserted into the stepped structure 242.
[83]
Specifically, the current blocking unit 244 may be configured to electrically connect the inner walls of the inner space of the stepped structure 242 spaced apart from each other. For example, the current blocking portion 244 may be configured to contact between the upper and lower walls 242b and 242c spaced apart from each other in the interior space of the stepped structure 242. Furthermore, the current blocking part 244 may be configured to contact the inner sidewall 242d of the interior space of the stepped structure 242.
[84]
In addition, the current blocking unit 244 may include a second metal having a relatively lower melting point than that of the first metal. Specifically, the second metal may be a material capable of transmitting electricity with a power loss of less than 40% due to high electrical conductivity. For example, the second metal may be aluminum. However, the second metal is not necessarily limited to aluminum, and any metal having a lower melting point and excellent electrical conductivity than the first metal may be used. For example, an aluminum alloy may be used.
[85]
Accordingly, according to this configuration of the present invention, as the current blocking portion 244 is formed in the inner space formed by the stepped structure 242 of the main body 241, overcurrent is generated in the bus bar 240 When flowing, the current blocking unit 244 including the second metal having a melting point lower than that of the first metal may melt first and flow down, thereby being lost to the outside of the bus bar 240. That is, the current blocking unit 244 is first melted and discharged from the stepped structure 242 of the main body 241, so that the current is concentrated in a thin portion of the stepped structure 242 of the main body 241 Accordingly, the step structure 242 of the main body 241 may be rapidly melted and lost. In this way, when an overcurrent is applied to the bus bar 240, the stepped structure 242 between the current blocking unit 244 and the main body 241 is quickly melted and lost, so that it can be quickly disconnected. have.
[86]
Here, the molten current blocking portion 244 may be discharged through a gap in communication with the outside between the covering member 245 and the body portion 241. Alternatively, it may be absorbed into the interior of the covering member 245 or may be discharged to the outside through the covering member 245.
[87]
Likewise, the stepped structure 242 of the molten body portion 241 may be discharged through a gap in communication with the outside of the covering member 245. Alternatively, it may be absorbed into the interior of the covering member 245 or discharged to the outside by passing through a plurality of pores formed in the covering member 245.
[88]
Further, a method of forming the current blocking portion 244 in the main body portion 241 of the bus bar 240 may be various. For example, the current blocking unit 244 may overlap the second metal plate with the second metal on a part of the first metal plate with the first metal, and then, in a high temperature environment, the second metal plate with the second metal plate. 1 It can be formed by rolling it inside a metal plate and bonding it mechanically. That is, the body portion 241 and the current blocking portion 244 of the bus bar 240 may be mechanically bonded to each other in a clad shape. In this case, a portion of each of the first metal plate and the second metal plate may have a form in which a first metal and a second metal are mixed with each other.
[89]
Accordingly, according to this configuration of the present invention, the main body 241 and the current blocking unit 244 are mechanically coupled through rolling, so that electrical connectivity between the main body 241 and the current blocking unit 244 Not only this may be very excellent, but also excellent bonding (adhesion), it is possible to prevent the durability of the bus bar 240 from becoming weak.
[90]
Alternatively, the bus bar 240 may form the body portion 241 and the current blocking portion 244 in a casting method. That is, after injecting the molten first metal into the mold frame, and curing the body portion 241 having the stepped structure 242 formed thereon, the molten second metal is used in the stepped structure of the body portion 241 ( 242) can be injected into the mold frame and sufficiently hardened to make it.
[91]
In addition, the area of ​​the cross-section orthogonal to the current flow direction S of the stepped portion 242a of the stepped structure 242 is the area of ​​the cross-section orthogonal to the current flow direction S of the current blocking portion 244 Can be less. In other words, a cross-sectional area in a horizontal direction orthogonal to the vertical direction of the stepped portion 242a of the stepped structure 242 may be less than a cross-sectional area of ​​the current blocking portion 244 in the horizontal direction.
[92]
That is, when an overcurrent is applied to the bus bar 240, the current blocking portion 244 is melted and a high resistance is generated in the stepped structure 242 of the main body 241. The cross-sectional area of ​​the stepped portion 242a of 242 may be configured to be relatively smaller than that of the current blocking portion 244.
[93]
Furthermore, the thickness z of the stepped portion 242a of the stepped structure 242 in the front-rear direction may be thinner than the thickness of the current blocking portion 244 in the front-rear direction. In addition, the outer surface of the stepped portion 242a of the stepped structure 242 may be positioned to face the inner surface of the current blocking portion 244. Here, the outer surface refers to an outer surface located in a direction toward the outside relative to the central portion of the battery module among the outer surfaces of the stepped structure. In addition, the inner surface means an outer surface of the outer surface of the step structure, which is located in a direction toward the central portion of the battery module from the outside.
[94]
Therefore, according to this configuration of the present invention, by configuring the thickness or cross-sectional area of ​​the stepped structure 242 of the main body 241 to be less than the thickness or cross-sectional area of ​​the current blocking unit 244, the step of the main body 241 The resistance may be high in the stepped portion 242a of the structure 242, and the thickness or area to be melted may be small, so that it can be reliably and quickly cut off. That is, the reliability and reaction speed of the fuse function of the bus bar 240 can be greatly increased.
[95]
5 is a partial cross-sectional view schematically showing a portion of a bus bar according to an embodiment of the present invention.
[96]
Referring to FIG. 5, the bus bar 240C shown in FIG. 5 connects between both inner walls of the stepped structure 242 and when compared with the bus bar 240 of FIG. 4, the current blocking portion 244 An extension part 243 provided with a first metal extending to cover the outer surface of) may be further formed. Specifically, the bus bar 240C may further include an extension part 243 configured to connect between the upper and lower walls 242b and 242c spaced apart from each other in the interior space of the stepped structure 242. . In addition, the extension part 243 may be extended to cover the outer surface 244b of the current blocking part 244.
[97]
For example, as shown in FIG. 5, the extension part 243 is formed so that the inner surface 243a of the extension part 243 faces the outer surface 244b of the current blocking part 244 I can make it. In addition, a stepped structure 242 may be formed on the main body 241 to face the inner surface of the current blocking unit 244.
[98]
Accordingly, according to this configuration of the present invention, the outer surface 244b of the current blocking unit 244 is covered on the bus bar 240 according to another embodiment, and the internal spaces of the stepped structure 242 are The current blocking part 244 is inserted into the stepped structure 242 of the main body 241 by configuring the extension part 243 configured to connect the spaced upper wall 242b and the lower wall 242c The durability of the damaged area can be further strengthened.
[99]
6 is a front view schematically showing a bus bar according to an embodiment of the present invention. And, FIG. 7 is a cross-sectional view schematically showing a portion of the bus bar cut along the line B-B' of FIG. 6.
[100]
Along with FIG. 4, referring to FIGS. 6 and 7, the covering member 245 may be made of a material having high heat insulation and excellent heat resistance. Specifically, the covering member 245 may include a mica material. In addition, the covering member 245 may be in the form of a thin sheet. For example, the covering member 245 may be a mica sheet. However, the covering member 245 is not necessarily limited to a mica sheet, and any sheet made of a material having excellent thermal insulation and heat resistance may be applied.
[101]
Moreover, the covering member 245 may be configured to surround at least a part of an outer surface of the current blocking portion 244. In addition, the covering member 245 may be configured to surround at least a part of an outer surface of the stepped structure 242 of the main body 241. For example, as shown in FIG. 7, the bus bar 240 may include a covering member 245 configured to surround a part of the outer surface of the current blocking unit 244 and the body unit 241. I can.
[102]
Accordingly, according to this configuration of the present invention, when the covering member 245 covers at least a part of the outer surface of the current blocking unit 244, when an overcurrent of more than a predetermined current is applied to the bus bar 240, Heat may be blocked so that the resistance heat generated in the current blocking unit 244 does not damage components adjacent to the bus bar 240. In addition, the covering member 245 insulates the current blocking unit 244, so that when an overcurrent is applied to the bus bar 240, the temperature of the current blocking unit 244 may be rapidly increased. Accordingly, it is possible to increase the speed of the response of the bus bar 240 to the overcurrent, thereby exhibiting a rapid current blocking function.
[103]
8 is a front view schematically showing some configurations of a bus bar according to another embodiment of the present invention. And, FIG. 9 is a cross-sectional view schematically showing a portion of the bus bar cut along the line C-C' of FIG. 8. Here, in FIG. 8, the current blocking portion and the covering member are omitted for convenience of description of the drawings.
[104]
8 and 9, the bus bar 240D according to another embodiment is compared with the stepped structure 242 of the main body 241 of FIG. 6, the main body 241 of FIG. The stepped structure 242D may further include a discharge structure inducing a molten current blocking portion to flow and discharge easily on the outer surface of the stepped portion 242e.
[105]
Specifically, the body portion 241 of FIG. 9 may have a stepped structure 242D in which an outer surface is inserted inwardly on a part, and in the stepped structure 242D of the main body 241, it is continuous in an outward direction. At least one inclined surface G1 formed by being internally inserted may be formed. In addition, the stepped portion 242e of the stepped structure 242D may be configured to continuously decrease in thickness in the inward direction as it approaches the end of the left and right direction W.
[106]
For example, as shown in FIGS. 8 and 9, a stepped portion 242e of the stepped structure 242D of the main body 241 has one inclined surface G1 extending from the center in the left-right direction W. ) Can be formed.
[107]
Accordingly, according to this configuration of the present invention, by forming an inclined surface G1 on the stepped portion 242e of the stepped structure 242D of the main body 241, when the current blocking unit is melted, the molten current blocking unit By inducing the flow along the inclined surface G1 to be discharged to the outside, discharge of the molten current blocking unit may be quickly and easily performed. Accordingly, the reactivity of the bus bar 240D to overcurrent can be further increased, and a quick disconnection can be achieved.
[108]
10 is a partial cross-sectional view schematically showing a portion of a bus bar according to another embodiment of the present invention.
[109]
Referring to FIG. 10 along with FIG. 2, a perforated outlet 245h may be formed in the covering member 245E so that the inside and the outside communicate with each other. Specifically, the outlet 245h may be a circular opening. Moreover, the outlet 245h may be formed in a portion facing the outer surface 244b of the current blocking portion 244E. In addition, the outlet 245h may be formed in a portion facing the stepped portion 242f of the stepped structure 242 of the main body 241.
[110]
For example, as shown in FIG. 10, five outlets 245h may be formed in the covering member 245E. Among them, the two outlets 245h may be configured to face the stepped portion 242f of the stepped structure 242 of the main body 241. In addition, among them, the three outlets 245h may be configured to face the outer surface 244b of the current blocking unit 244E.
[111]
Accordingly, according to this configuration of the present invention, by forming the outlet 245h in the covering member 245E, the melted current blocking portion 244E or the stepped structure 242 of the main body 241 It may help to smoothly discharge the stepped portion 242f to the outside through the discharge port (245h). Accordingly, it is possible to quickly disconnect the bus bar 240E against overcurrent.
[112]
In addition, at least one perforated through hole 242h may be formed in the stepped portion 242f of the stepped structure 242 of the main body 241 so as to communicate inside and outside.
[113]
Further, the current blocking part 244E may have a protruding protrusion structure 244p extending through a through hole 242h formed in the stepped portion 242f of the stepped structure 242 on a part of the current blocking portion 244E. Further, the through hole 242h formed in the stepped portion 242f of the stepped structure 242 may be positioned to communicate with the outlet 245h of the covering member 245E.
[114]
For example, as shown in FIG. 10, two through holes 242h may be formed in the stepped portion 242f of the stepped structure 242 of the main body 241. In addition, a protruding structure 244p extending through one of the two through holes 242h may be formed in the current blocking portion 244E. Further, the two through holes 242h may be positioned to communicate with the outlet 245h of the covering member 245E.
[115]
Therefore, according to this configuration of the present invention, by forming a through hole 242h in the stepped portion 242f of the stepped structure 242 of the main body 241, the molten current blocking portion 244E is penetrated. It can help to be discharged to the outside through the hole (242h). In addition, the through hole 242h is positioned so as to communicate with the outlet 245h of the covering member 245E, so that the molten current blocking portion 244E discharged through the through hole 242h is re-exposed to the covering member. It can be finally discharged to the outside through the outlet (245h) of (245E). Accordingly, the reactivity of the bus bar 240E to overcurrent can be further increased, and a quick disconnection can be achieved.
[116]
11 is a front view schematically showing some configurations of a bus bar according to another embodiment of the present invention. Here, in FIG. 11, the covering member is omitted for convenience of description of the drawing.
[117]
Referring to FIG. 11, in the bus bar 240G of FIG. 11, at least one slit 244L may be formed in the current blocking portion 244G. Here, the slit 244L may be a narrow and long gap (hole).
[118]
In addition, the number and size of the slits 244L may be set in consideration of an appropriate resistance size to be provided so that the current blocking unit 244G can properly perform a fuse function. That is, as the number and size of the slits 244L increase, the cross-sectional area in the horizontal direction orthogonal to the vertical direction of the current blocking unit 244G decreases, so that the electric resistance level may increase when energized. For example, as shown in FIG. 11, two slits 244L may be formed in the current blocking portion 244G.
[119]
Therefore, according to this configuration of the present invention, by forming at least one slit 244L in the current blocking unit 244G, the appropriate resistance size to have so that the current blocking unit 244G can properly perform a fuse function. Can be set. Accordingly, a fuse function with higher accuracy can be performed.
[120]
12 is a perspective view schematically showing a battery module according to an embodiment of the present invention.
[121]
Referring to FIG. 12 along with FIGS. 1 and 3, the battery module 300 according to the present invention includes at least one bus bar 240, a bus bar frame 230, and the plurality of secondary batteries 100. The module housing 210 may be included.
[122]
Here, the bus bar 240 may be configured to be electrically connected to a plurality of secondary batteries 100. In addition, the battery module 300 may have the same structure and configuration as the bus bar 240 described above.
[123]
In addition, the busbar frame 230 may be made of an electrically insulating material. For example, the bus bar frame 230 may include at least a part of a plastic material. Furthermore, the busbar frame 230 may be manufactured through injection molding.
[124]
In addition, the bus bar frame 230 may include a mounting portion 232 to mount the bus bar 240 on an outer surface. Here, the outer surface of the bus bar frame 230 means an outer surface of the outer surface of the bus bar frame 230 that is located in a direction toward the outside relative to the central portion of the battery module 300. In addition, the inner surface refers to an outer surface of the outer surface of the bus bar frame 230 located in a direction toward the central portion of the battery module from the outside.
[125]
A fixing structure capable of mounting and fixing the bus bar 240 may be formed on the mounting part 232. For example, a fastener 240i or a fixing groove 240g may be formed in the bus bar 240, and the mounting portion 232 of the bus bar frame 230 penetrates the fastener 240i, or the A fixing protrusion 232p inserted into the fixing groove 240g may be formed.
[126]
For example, as shown in FIG. 12, a fixing groove 240g inserted inward may be formed on the upper portion of the bus bar 240. In addition, a fastener 240i may be formed under the bus bar 240. The fixing protrusion 232p formed on the mounting portion 232 may be inserted into the fixing groove 240g in an upward direction, and the fixing protrusion 232p may be inserted through the fixing tool 240i.
[127]
Therefore, according to this configuration of the present invention, by forming a fixing structure to fix the bus bar 240 to the mounting portion 232 formed on the bus bar frame 230, the bus bar 240 can be stably fixed. In addition, an electrical and physical connection structure between the bus bar 240 and the plurality of secondary batteries 100 may be stably maintained. Accordingly, the durability of the battery module 300 can be effectively increased.
[128]
Meanwhile, a battery pack (not shown) according to the present invention may include one or more battery modules 300 according to the present invention. In addition, the battery pack according to the present invention includes, in addition to the battery module 300, a pack case for accommodating the battery module 300, various devices for controlling charge/discharge of the battery module 300, such as BMS (Battery Management System), a current sensor, a fuse, etc. may be further included.
[129]
In addition, the battery pack according to the present invention can be applied to a moving means such as a vehicle. For example, the electric vehicle according to the present invention may include the battery pack according to the present invention.
[130]
On the other hand, in this specification, terms indicating directions such as up, down, left, right, before, and after are used, but these terms are for convenience only and vary depending on the location of the object or the observer. It is obvious to those skilled in the art of the present invention.
[131]
[132]
As described above, although the present invention has been described by limited embodiments and drawings, the present invention is not limited thereto, and the technical idea of ​​the present invention and the following by those of ordinary skill in the art to which the present invention pertains. It goes without saying that various modifications and variations are possible within the equivalent range of the claims to be described.
[133]
[Explanation of code]
[134]
100: secondary battery 110: electrode lead
[135]
300: battery module
[136]
210: module housing
[137]
230: busbar frame 232: mounting portion
[138]
240: bus bar
[139]
241: main body 242: step structure
[140]
242a: stepped region 243: extension
[141]
242h: through hole
[142]
244: current cut-off unit 244L: slit
[143]
245: covering member 245h: outlet
[144]
244p: protruding structure 250: connecting busbar
Industrial availability
[145]
The present invention relates to a bus bar having a current blocking portion and a battery module including the same. In addition, the present invention is applicable to industries related to battery packs, automobiles, and electronic devices having the above battery modules.
Claims
[Claim 1]
A main body configured to be provided in the battery module, having a first metal, having a stepped structure in which an outer surface of the battery module is inserted in an inward direction is formed on a part, and configured to be electrically connected to one or more secondary batteries; A current blocking unit including a second metal having a melting point relatively lower than that of the first metal and inserted into a space formed by inserting the outer surface of the stepped structure inward; And a covering member configured to surround at least a portion of an outer surface of the current blocking portion.
[Claim 2]
The bus bar of claim 1, wherein the current blocking unit is configured to electrically connect an upper wall and a lower wall spaced apart from each other in the interior space of the stepped structure.
[Claim 3]
The bus bar according to claim 1, wherein an area of ​​a cross section orthogonal to a current flow direction of the stepped portion of the stepped structure is less than an area of ​​a cross section orthogonal to a current flow direction of the current blocking portion.
[Claim 4]
The method of claim 2, wherein the outer surface of the stepped portion of the stepped structure is positioned to face the inner side of the current blocking portion, and connects the upper and lower walls spaced apart from each other of the interior space of the stepped structure. A bus bar, characterized in that an extension portion extending to cover an outer surface of the current blocking portion is formed.
[Claim 5]
The bus bar of claim 2, wherein at least one slit is formed in the current blocking portion.
[Claim 6]
The bus bar according to claim 2, wherein a perforated discharge port is formed in the covering member to communicate inside and outside.
[Claim 7]
The bus bar according to claim 6, wherein a through hole is formed in the stepped portion of the stepped structure so that the inside and the outside communicate with each other.
[Claim 8]
The bus bar of claim 7, wherein the current blocking portion has a protruding structure extending through a through hole formed in a stepped portion of the stepped structure.
[Claim 9]
The bus bar according to claim 8, wherein the through hole formed in the stepped portion of the stepped structure is positioned so as to communicate with an outlet of the covering member.
[Claim 10]
The bus bar according to claim 1, wherein the covering member is a mica sheet.
[Claim 11]
A plurality of secondary batteries; A battery module comprising a bus bar according to claim 1 configured to electrically connect the plurality of secondary batteries to each other, and a bus bar frame including an electrically insulating material and configured to mount the bus bar on an outer surface.
[Claim 12]
A battery pack comprising at least one battery module according to claim 11.