KR102116188B1 - Battery pack for energy storage system - Google Patents

Abstract

The present invention relates to a battery pack for energy storage, a battery pack comprising a plurality of battery cells made of a cylindrical steel material and a bus bar that electrically connects the electrode terminals of the battery cells, having high conductivity and heat generation characteristics. A bus bar comprising a terminal of an Al material and a first bus bar and a second bus bar, and including a junction connected to a plurality of battery cells arranged in series and parallel to the first bus bar via laser welding; A terminal extending from the bus bar; It characterized in that it comprises a cell holder having an insertion hole for accommodating one end of the battery cell, securing the expandability of the battery pack and packaging the battery pack module by various bonding, bolting, inserting, etc. It fundamentally prevents electrical contact resistance, which inevitably occurs at multiple connection points, and solves the problem of low charge / discharge efficiency and reduced durability due to balance damage or hot spots caused by non-uniform contact resistance, thereby providing vibration resistance and operation of the battery pack. It has the effect of ensuring stability.

Description

Battery pack for energy storage system

The present invention relates to a battery pack for energy storage, more specifically to secure the expandability of the battery pack and packaging the battery pack module with various bonding, bolting, inserting, etc., inevitably occurs at a number of connection points generated thereby The battery pack for energy storage that fundamentally prevents electrical contact resistance and solves the problem of low charge and discharge efficiency and reduced durability due to balance damage or hot spots caused by non-uniform contact resistance. will be.

Unlike primary batteries that cannot be charged, secondary batteries that can be charged and discharged are actively researched through the development of high-tech fields such as digital cameras, cellular phones, laptop computers, power tools, electric bicycles, electric vehicles, hybrid vehicles, and large-capacity power storage devices. Is in progress.

In particular, lithium secondary batteries have high energy density per unit weight and can be rapidly charged compared to other secondary batteries such as lead-acid batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. Is going on.

Lithium secondary batteries have a working voltage of 36V or higher and are used as power sources for portable electronic devices, or multiple batteries are connected in series or parallel to be used in high-power electric vehicles, hybrid vehicles, power tools, electric bicycles, power storage devices, UPS, etc. do.

Here, the cylindrical secondary battery includes an electrode assembly and an electrolyte, and the electrode assembly includes a positive electrode plate, a negative electrode plate, and a separator, and the electrolyte solution often includes lithium ions, and the positive electrode plate and negative electrode plate of the electrode assembly are electrode tabs that are drawn out. Each may be provided.

The electrode assembly is accommodated inside the casing, and an electrode terminal may be exposed outside the casing. The electrode tab may be drawn out of the electrode assembly and electrically connected to the electrode terminal.

A plurality of such secondary cells may be stacked horizontally or vertically to form a battery pack. Secondary cells stacked adjacent to each other in the battery pack may be electrically connected to electrode terminals, and electrode terminals of neighboring secondary cells may be connected to a bus bar, It can be electrically connected by a booth plate.

As an example of such a battery pack, for example, Republic of Korea Patent Publication No. 2016-111457, as can be seen in Figure 8, the energy storage system includes an interconnected array of energy storage elements in which two cells are represented, They are physically held and held in place (eg, with a specific torque value) by a pair of opposing clamshells (top clamshell 104 and bottom clamshell 106). For example, cramshells have openings that expose each end of each cell. In other embodiments, the cells can be secured by other techniques, such as a structure interleaved between cells.

Here, the flexible printed circuit 108 lays and connects the electrical terminals of the battery 102 thereon. In this embodiment, the flexible printed circuit includes three layers in which the flexible conductive layer 110 is interposed between the flexible lower insulating layer 112 and the flexible upper insulating layer 112. The conductive layer may be a uniform metal layer such as copper, and the insulating layer may be a uniform polyimide layer (for example, Kapton (registered trademark) material). In other embodiments, one or more other materials may be used in place of or in combination with the materials described above.

Here, the cell 102 is a type of rechargeable battery cell having a flat top with terminals at one end. In particular, each cell has a central positive terminal 116 and a peripheral annular negative terminal 118. For example, the annular negative terminal is part of the battery's main housing (eg, battery can) that extends along the length of the battery and forms the other end of the battery (ie, the lower end in this example), or It can be mounted on.

The patterning of the flexible printed circuit 108 forms a die cut region 120 in the lower insulating layer 112 so that exposed portions of the conductive layer 110 can be electrically contacted, for example, terminals of the battery (s) Enable selective connection to the field. Here, the die cut region 122 of the upper insulating layer 114, the exposed layer of the conductive layer 110, the base layer to be bonded to the portion of the conductive layer that interacts with the device (for example, the battery ( 102) terminal). In making electrical junctions, any of a number of different types of devices and techniques can be used. For example, here, by spot welding 124, portions of the conductive layer 110 are bonded to each terminal of each cell.

Such an energy storage system can be implemented simply as, for example, a propulsive energy source in an electric vehicle. That is, in the energy storage system, a plurality of cells may be interconnected to form an array (eg, a battery pack) that operates a vehicle.

However, the battery pack of this structure is an integrated module and may help to secure reliability, but the rigidity of the pack itself increases because it has a number of connection points such as flexible bonding processing, booth plate bonding, and battery cell fixed bonding. As a result, there was a problem of insufficient scalability in the module.

Republic of Korea Patent Publication No. 2016-111457

Therefore, the technical problem to be solved by the present invention is to secure the expandability of the battery pack and package the battery pack module with various bonding, bolting, inserting, etc., thereby inducing the electrical contact resistance inevitably generated at a plurality of connection points. It aims to provide a battery pack that fundamentally prevents and solves the problem of low charge and discharge efficiency and reduced durability due to balance damage or hot spots caused by non-uniform contact resistance, thereby ensuring vibration resistance and operational stability.

The present invention is a means for achieving the above object,

In a battery pack comprising a plurality of battery cells made of a cylindrical cylinder made of steel, and a bus bar for electrically connecting the electrode terminals of the battery cells, a terminal and a first bus bar made of Al and having high conductivity and heat generation characteristics. A bus bar made of 2 bus bars, and including a junction connected to a plurality of battery cells arranged in series and parallel to the first bus bar through laser welding; A terminal extending from the bus bar; It provides a battery pack for energy storage, characterized in that it comprises a cell holder with an insertion hole for receiving one end of the battery cell.

The bus bar of the present invention has a first bus bar and a first bus bar having a junction part facing the electrode terminal of the battery and being joined, the junction part being spaced apart from the bus bar, and having a plurality of unit conducting parts connected to a buffer leg. It is provided on the upper portion of the bus bar, but is characterized in that it comprises a second bus bar which is partially in contact with the first bus bar and has a shape to have an open preventing property due to vibration.

The first bus bar and the second bus bar of the present invention are arranged symmetrically, characterized in that the battery module to be fixed through a plurality of battery cells.

The first bus bar and the second bus bar of the present invention are arranged symmetrically, characterized in that the battery module to be fixed through a plurality of battery cells.

The junction of the first bus bar of the present invention is characterized in that it is less than the thickness of the negative terminal of the battery cell.

The first bus bar of the present invention is characterized in that it is equal to or thinner than the thickness of the second bus bar.

The cell holder of the present invention is characterized by having a plurality of latch portions protruding so as to be in close contact with one end side of the battery cell.

The cell holder of the present invention is characterized in that it is oriented according to the arrangement of the battery cells in plural.

The cell holder of the present invention is characterized in that it has a structure in which a flat unit area (Scan area) is repeated so that a plurality of cells can be joined by a laser beam scan, and includes a protruding coupling portion located between the unit sections.

The terminal of the present invention is characterized in that a fastening hole or a nut hole is formed.

According to the battery pack for energy storage according to the present invention, to secure the expandability of the battery pack and packaging the battery pack module with a variety of bonding, bolting, inserting, etc., electrical contact resistance inevitably occurs at a plurality of connection points generated thereby It prevents fundamentally and solves the problem of low charge and discharge efficiency and reduced durability due to balance damage or hot spots caused by non-uniform contact resistance, thereby guaranteeing vibration resistance and operational stability of the battery pack.

1 is a perspective view showing a cell holder, a battery cell, and an integrated bus bar disposed inside the battery pack according to the present invention;
2 is a perspective view showing a cell holder of the present invention and a view showing a latch provided on the side,
3 is a view showing an embodiment according to the bus bar of the present invention by separating the first and second bus bars,
4 is a view showing a separate embodiment of the first and second bus bars according to the bus bar of the present invention,
5 is a plan view showing a fastening hole and a nut hole provided in the terminal and the BMS holder of the present invention,
6 is a view showing a shape in which a plurality of cell holders of the present invention are applied to package battery modules of various electric capacities,
7 is a perspective view of a battery pack according to the present invention exposed by each component,
8 is a view showing a part of a side of a conventional battery pack.

Hereinafter, it should be noted that the technical terms used in the present invention are only used to describe specific embodiments, and are not intended to limit the present invention, and the technical terms used in the present invention have special meanings in the present invention. Unless defined, the present invention should be interpreted as meanings generally understood by those skilled in the art to which the present invention pertains, and should not be interpreted as an excessively comprehensive meaning or an excessively reduced meaning.

In addition, when the technical term used in the present invention is a wrong technical term that does not accurately represent the spirit of the present invention, it should be understood as being replaced by a technical term that can be correctly understood by those skilled in the art. In addition, the general terms used in the present invention should be interpreted as defined in the dictionary or in context before and after, and should not be interpreted as an excessively reduced meaning.

In addition, the singular expression used in the present invention includes a plurality of expressions unless the context clearly indicates otherwise, for example, the terms "consisting of" or "comprising" include various components described in the present invention, or It should not be construed as including all of the various steps, and some of the components or some steps may not be included, or it may be interpreted as further including additional components or steps.

Hereinafter, a battery pack for energy storage according to the present invention will be described in detail through the accompanying drawings.

1 is a perspective view showing a cell holder, a battery cell, and an integrated bus bar disposed inside the battery pack according to the present invention, and FIG. 2 is a perspective view showing the cell holder of the present invention and a latch provided on the side FIG. 3 is a view showing the first and second busbars in one embodiment according to the busbar of the present invention, and FIG. 4 is the first and second busbars in another embodiment according to the busbar of the present invention. Figure 5 is a plan view showing the fastening hole and the nut hole provided in the terminal and the BMS holder of the present invention, Figure 6 is a plurality of cell holders of the present invention is applied to package a battery module of various electric capacity It is a view showing a shape, and FIG. 7 is a perspective view of a battery pack according to the present invention and exposed by each component.

When described in detail with reference to Figures 1 to 7, the energy storage battery pack according to the present invention is a plurality of battery cells 100, the battery cell 100 is coupled to the cell holder 300, a plurality of cell holders It is installed on the upper portion of the 300 includes a bus bar 200 that allows the battery cell 100 to be energized.

And the battery pack for energy storage according to the present invention further includes a case member 400 and a BMS holder 500 that surround and protect the exterior of the battery pack.

The plurality of battery cells 100 are formed in a cylindrical shape and are installed between the plurality of cell holders 300.

The cell holder 300 includes an upper holder 310 and a lower holder 320 in which an insertion hole 330 is formed to be coupled to the upper and lower portions of the battery cell 100.

In addition, the upper holder 310 and the lower holder 320 are repeatedly formed with a flat unit area (scan area) so that a plurality of battery cells 100 can be joined by laser beam scanning, and protrusions and grooves are formed on the side surfaces. The adjacent upper holder 310 is formed with a latch portion 340 that is coupled to each other.

That is, the latch part 340 allows the cell holder 300 and the cell holder 300 to be connected. The latch part 340 is not only configured in the upper holder 310 but is also formed in the lower holder 320.

One side of the upper holder 310 is formed with a protruding coupling portion 350 so that the bus bar 200 can be coupled.

The protruding coupling part 350 is positioned between sections in which a flat unit area is repeatedly formed so that the plurality of battery cells 100 can be joined by laser beam scanning.

In addition, the cell holder 300 is a terminal of a designed voltage constituting a battery module by being oriented according to the arrangement of the battery cells 100, and is accommodated in the cell holder 300 according to the size of the bus bar 200 integrally provided. It can be provided according to the number of the battery cells 100 to ensure the expandability of the battery pack.

Preferably, the battery cell 100 is formed of 16 to 20 of the insertion hole 330 of the cell holder 300 that can be used in a modular battery module, so that the standardization of the cell holder 300 can be determined.

In addition, the cell holder 300 does not specifically limit the material as long as the battery cell 100 can be fixed, but the battery cell 100 is arranged by injecting it with a plastic material to prevent a short circuit or a short circuit. It can be prevented from being distorted or dislodged during use.

The bus bar 200 includes a first bus bar 220 and a second bus bar 210.

In addition, the first bus bar 220 and the second bus bar 210 are symmetrically arranged, and are characterized in that they are battery modules fixed through a plurality of battery cells 100.

The first bus bar 220 is in contact with the battery cell 100 is made of a high output current to pass through, as well as a heat sink (heat sink) function to release heat.

The first bus bar 220 is spaced apart a predetermined distance is formed so that the unit is energized to the battery cell 100, the unit conduction unit 220 'is formed, the unit conduction unit 220' is a plurality of junctions 221 It consists of a buffer leg (222).

In addition, the first bus bar 220 is preferably made of Al material and formed to a thickness of 0.3 mm, but is not limited thereto, and may be formed to be equal to or thinner than the thickness of the second bus bar 210. .

In addition, the opening portion through which the battery cell 100 is introduced is formed larger than the junction portion 221 of the unit energizing portion 220 ′, which is to secure the area of the junction portion 221 and to avoid interference during beam scan. .

The junction portion 221 is provided to be spaced apart from the first bus bar 220 so that the electrode terminals of the battery cell 100 are bonded to conduct electricity, and the plurality of buffer legs 222 are the junction portion 221 and the first The bus bar 220 is connected.

The junction portion 221 is preferably formed to a thickness less than or equal to the negative terminal of the battery cell.

That is, the bonding portion 221 is disposed in contact with the electrode terminal, it is possible to weld the portion to enable electrical conduction, usually, the positive electrode terminal has a cap up (cap up) is an electrode with a protrusion and a vent hole for laser welding Even though it is penetrated by high energy, there is less risk of damage to the inside of the secondary battery, but the bottom surface of the battery cell 100, which is the negative terminal, has a concern that a defect of the secondary battery may occur immediately when damage occurs in the battery cell 100 material. have.

The joining portion 221 can prevent occurrence of defects due to welding by performing resistance welding. In this case, aluminum or copper can be used as a material capable of resistance welding, as well as copper coated with nickel or tin. Can be used.

Furthermore, by adopting nickel, nickel alloy, copper, nickel silver, iron or SPCE in the form of plate or strip, it is possible to form joints and extensions through press processing, which is excellent in workability and may occur over time. In addition, it is possible to prevent an increase in contact resistance. In particular, the metal constituting the electrode terminal including the positive electrode terminal and the negative electrode terminal is often nickel or nickel alloy. have.

In addition, a gas hole 223 is formed between the buffer leg 222 and the buffer leg 222, and the gas hole 223 allows gas to be discharged when the battery cell 100 is vented.

A terminal 212 is further configured on one side of the first bus bar 220, and the terminal 212 is formed with a bolt so that the BMS holder 500 can be coupled.

The second bus bar 210 has a plurality of entry holes 211 are formed at predetermined intervals so as to be laser-bonded in close contact with one side of the first bus bar 220, due to vibration. It is made to have an open preventing property. The second bus bar 210 is made of Al and has a thickness of 0.5 mm to 1 mm.

The above open-preventing property prevents an open that may be electrically generated between the electrode terminal and the joint due to various vibrations occurring during the operation of the vehicle, and is secured by bonding or fixing that ensures durability between the electrode terminal and the joint. Can be.

The case member 400 is installed on top of a plurality of battery cells 100, a cell holder 300 to which the battery cells 100 are coupled and energized, and a plurality of cell holders 300 to energize the battery cells 100. The outer cover of the battery pack including the bus bar 200 to be protected is protected.

In addition, the case member 400 is composed of an upper case 410 and a lower case 420 to be assembled or separated by fastening means such as bolts and nuts.

In addition, a plurality of spacers may be further formed on the case member 400 in which the battery pack for energy storage according to the present invention is installed, and heat dissipation is facilitated by the spacers.

The terminal 212 is extended from the bus bar 200 to be bent to form a fastening hole, and the fastening hole is coupled with a bolt of the terminal to extend in a block shape.

In addition, the present invention, as shown in Figure 1, by installing a sub-bus bar (unsigned) on the top of the adjacent bus bar 200 can be connected to pass current, as well as the durability between the electrode terminal and the junction is secured It is combined so that it can be fixed.

As illustrated in FIG. 1, the sub-bus bar may be installed only on the upper side of the battery cell 100 or on the lower side.

The BMS holder 500 is configured with an insert-formed nut hole 510 to be coupled to a bolt formed on a terminal, and is formed in a square shape as shown in the drawing to charge or discharge the current of the battery cell 100. So that the BMS (Battery Management System) is installed.

As described above, the battery pack for energy storage according to the present invention secures expandability of the battery pack and inevitably occurs at a plurality of connection points generated by packaging the battery pack module with various bonding, bolting, and inserting. Basically prevents electrical contact resistance.

In addition, it solves the problem of low charge and discharge efficiency and reduced durability due to damage to the balance due to non-uniform contact resistance or occurrence of hot spots, thereby guaranteeing vibration resistance and operational stability of the battery pack.

Although described above with reference to preferred embodiments of the present invention, the protection scope of the present invention is not limited to the above embodiments, and those skilled in the art will not depart from the spirit and scope of the present invention. It will be understood that various modifications and changes may be made to the present invention within the scope.

100: battery cell 200: bus bar
210: Second bus bar 211: Entrance hall
212: Terminal 220: 1st bus bar
220 ': unit energized part 221: junction
222: buffer leg 223: gas hole
300: cell holder 310: upper holder
320: lower holder 330: insertion hole
340: latch portion 350: engaging portion
400: case member 410: upper case
420: lower case 500: BMS holder
510: nut hole

Claims (8)

In the battery pack including a plurality of battery cells made of a cylindrical steel material (100), and a bus bar (200) electrically connecting the electrode terminals of the battery cells (100),
Directly connected to a plurality of battery cells 100 made of a terminal made of Al material having high conductivity and heat generation characteristics, a first bus bar and a second bus bar, and arranged in series and parallel to the first bus bar 220. A bus bar 200 including a junction 221 to be joined through laser welding,
A terminal 212 extending from the bus bar 200;
Includes; cell holder 300 having an insertion hole 330 for receiving one end of the battery cell 100;
It comprises a plurality of battery cells 100, the bus bar 200 and the case member 400 that surrounds and protects the exterior of the cell holder 300 and the BMS holder 500 coupled to the terminal 212,
The case member 400 has a plurality of spacers to facilitate heat dissipation and is composed of an upper case 410 and a lower case 420 to be assembled or separated by fastening means such as bolts and nuts,
The BMS holder 500 includes an insert-formed nut hole 510 that is formed in a square shape so that a battery management system (BMS) is installed to charge or discharge the current of the battery cell 100, and is coupled to a bolt formed in the terminal. Battery pack for energy storage, characterized in that.
According to claim 1,
The bus bar 200,
It is provided with a bonding portion 221 that is opposite to the electrode terminal of the battery is bonded,
The junction 221 is spaced apart from the bus bar 200, the first bus bar 200 having a plurality of unit energizing parts connected to the buffer leg 222 and
It is provided on the upper portion of the first bus bar 200,
A second bus bar 200 partially formed in contact with the first bus bar 200 and having a shape to prevent openness due to vibration;
A battery pack for energy storage comprising a.
According to claim 2,
The first bus bar 220 and the second bus bar 210,
A battery pack for energy storage, which is arranged symmetrically and is a battery module that is fixed through a plurality of battery cells (100).
According to claim 2,
The junction portion 221 of the first bus bar 220,
Battery cell (100) Battery pack for energy storage, characterized in that less than the thickness of the negative terminal.
The method of claim 4,
The first bus bar 220,
A battery pack for energy storage, characterized in that it is equal to or thinner than the thickness of the second bus bar 210.
According to claim 1,
The cell holder 300,
The battery pack for energy storage, characterized in that it has a plurality of latch portions 340 protruding to be in close contact with one end side of the battery cell (100).
The method of claim 6,
The cell holder 300,
A battery pack for energy storage, characterized in that it is oriented according to the arrangement of the battery cells 100 in plural.
delete

Images