KR100875606B1 - Secondary battery module - Google Patents

Abstract

The present invention relates to a high-output large capacity secondary battery module or pack capable of charging and discharging by electrically connecting a plurality of unit cells, wherein the unit cells are stacked and mounted between a plate or an upper case and a lower case which are preferably separated from each other. In addition, circuit parts such as sensing the voltage, current and temperature of the battery, controlling the battery, and powering down the battery during overcurrent are continuously installed on the side of the module, so it is easy to expand and contract flexibly according to the desired electric capacity and output. In addition, the electrical connection between the unit cells can be performed stably, and the mounting of the elements constituting the battery module and the wiring for the electrical connection can be made compact, and the mounting of the unit cells in the module can be realized in a simple manner. And efficient heat dissipation can be achieved.

Description

Secondary Battery Module             

1 is a schematic perspective view of a battery module according to an embodiment of the present invention;

2 is a side view of FIG. 1;

3A is a schematic diagram illustrating a process of stacking a lower case and unit cells thereon in the battery module of FIG. 1;

3B is a bottom perspective view of the lower case in the battery module of FIG. 1;

4 is a bottom perspective view of the upper case in the battery module of FIG.

<Description of Major Symbols in Drawing>

100: battery module 200: upper case

300: lower case 400: unit cell

500: first circuit portion 600: second circuit portion

700: third circuit portion 800: fastener

900: insulation member 1000: double-sided adhesive tape

The present invention relates to a high-output large capacity secondary battery module or pack capable of charging and discharging by electrically connecting a plurality of unit cells, and more particularly, a unit between an upper case and a lower case which are separated from each other or a plate. Circuit parts such as stacking batteries, sensing battery voltage, current and temperature, controlling batteries, and powering down during overcurrent are continuously installed on the side of the module to provide overall compact and desired electric capacity and output. Accordingly, it is possible to flexibly change the design and provide a rechargeable battery module in which components are stably mounted.

Recently, secondary batteries capable of charging and discharging have been widely used as energy sources of wireless mobile devices. In addition, the secondary battery has attracted attention as an energy source of electric vehicles, hybrid electric vehicles, etc. which are proposed as a solution for air pollution of conventional gasoline and diesel vehicles using fossil fuel. Therefore, the type of applications using the secondary battery is very diversified due to the advantages of the secondary battery, and it is expected that the secondary battery will be applied to many fields and products in the future.

As the application fields and products of secondary batteries are diversified as described above, the types of batteries are also diversified to provide outputs and capacities suitable for them. In addition, batteries applied to the art and products are strongly required for small size and light weight.                         

For example, small mobile devices such as mobile phones, PDAs, digital cameras, notebook computers, and the like are used with one or three or four small and light battery cells per device according to the miniaturization tendency of the products. On the other hand, medium and large devices such as electric bicycles, electric vehicles, hybrid electric vehicles, etc., due to the need for high output and large capacity, battery modules (or sometimes referred to as "battery packs") that electrically connect a plurality of battery cells are used. Since the size and weight of the battery module are directly related to the accommodation space and output of the medium and large devices, manufacturers are trying to manufacture a battery module that is as small and lightweight as possible. In addition, devices that receive a lot of shocks and vibrations from the outside, such as electric bicycles and electric vehicles, should have a stable electrical connection state and physical coupling state between the elements constituting the battery module. Safety aspects are also important because they must be implemented.

In addition, as described above, as the products using secondary batteries in the medium and large device field are diversified, various electric modules capable of providing appropriate capacitance and output are required. In this case, the required capacitance and output also vary, so the design of the battery module must be changed.

The conventional medium-large size secondary battery module has a structure in which a plurality of unit cells are housed in a case (housing) of a predetermined size and electrically connected thereto, and the voltage, current, temperature, etc. of the unit cells are detected on the outer surface of the case. Circuit parts such as controlling the battery are connected. However, the structure of such a battery module has many problems.

First, it is not easy to expand or contract the battery module depending on the desired capacitance and output. Since unit cells are specifically designed with a case of a certain size and various elements having a structure corresponding to such a case, when the unit cells are added to increase the output, for example, the design of the entire battery module must be greatly changed. I have a problem.

Second, since the electrical connection of the unit cells is not easy, the manufacturing process of the battery module is complicated, and the specific structure of the member for connecting them makes the overall size of the battery module larger, and the connection state also has high reliability. Can not provide. Pouch-type batteries are widely used as unit cells of the battery module. In order to electrically connect the pouch-type batteries, the plate-shaped electrode leads must be interconnected by welding or the like, but are not easy in terms of the structure of the electrode leads. For example, a method of welding a bus bar to electrode terminals is used, but has a fundamental problem as described above.

Third, a large number of devices and wirings mounted outside the case or for electrical connection are generally not compactly configured (high density), thereby increasing the size of the battery module and providing high safety against external shocks.

Fourth, a separate member such as a cartridge is generally used for a stable coupling between unit cells in the module, and such a member complicates the assembly process of the battery module and increases the overall size of the module.

Accordingly, an object of the present invention is to solve the problems of the prior art as described above and the technical problems that have been requested from the past.

In particular, it is an object of the present invention to provide a battery module that is designed to be easily expanded and collapsed in accordance with the desired capacitance and output.

It is still another object of the present invention to provide a battery module designed to compactly configure wirings for electrical connection with respective elements of the battery module.

Another object of the present invention is to provide a battery module designed to stably perform electrical connection between unit cells by a simple structure.

Yet another object of the present invention is to provide a battery module designed to mount unit cells in a module in a simple manner and to provide efficient heat dissipation.

The battery module according to the present invention for achieving the above object is a module capable of electrically charging and discharging a high output large capacity by electrically connecting a plurality of unit cells, a plurality of unit cells which are chargeable and dischargeable secondary batteries are stacked And a circuit portion for controlling the operation of the battery.                     

The plate is not particularly limited as long as it is a structure in which the unit cells can be stacked, and may be a case structure in which an accommodating part corresponding to the size of the unit cell is formed so as to facilitate the installation of the unit cells. The case may have a separate structure covering upper and lower portions of the unit cells in which the case is stacked.

In one preferred example, the secondary battery module,

A plurality of unit cells which are rechargeable batteries capable of charging and discharging;

A rectangular lower case including an upper accommodating portion in which the unit cells are sequentially stacked;

A rectangular upper case including a lower accommodating part covering an upper end of unit cells stacked on the lower case;

A first circuit unit including a sensing board assembly configured to electrically connect the stacked unit cells and detect a voltage and / or a current of the battery;

A second circuit portion electrically connected to the first circuit portion and including a main board assembly for overall control of the module; And

A third circuit portion electrically connected to the second circuit portion and connected to an external output terminal while preventing overcharge, overdischarge, and / or overcurrent;

It is configured to include.

Since the overall width and length of the battery module according to the present invention is slightly larger than the unit cell, the overall size is very small. Therefore, since the volume increase of the pack due to the modularization is minimized, it can be effectively mounted on the external device or device to be applied.                     

The unit cell is not particularly limited as long as it is a secondary battery capable of charging and discharging, and examples thereof include lithium secondary batteries, nickel-hydrogen (Ni-MH) batteries, nickel-cadmium (Ni-Cd) batteries, and the like. Among them, a lithium secondary battery that provides a high output to weight may be preferably used. The lithium secondary battery is classified into a cylindrical battery, a square battery, a pouch-type battery, etc., depending on the shape, among which a rectangular battery and a pouch-type battery that can be stacked with high integration are preferable, and a light weight pouch-type battery is particularly preferable. .

In a preferred embodiment of the present invention, the battery module is designed to be flexible by adding or removing unit cells between the upper case and the lower case when the upper case and the lower case are separated from each other, and when the capacity and output are to be changed as necessary. Is possible.

The overall size of the upper case and the lower case is about the size of the unit cell. Therefore, the upper accommodating part of the lower case in which the unit cell is accommodated and the lower accommodating part of the upper case correspond to the body size of the unit cell.

In one preferred example, a double-sided adhesive member may be interposed between the unit cells to be stacked. This double-sided adhesive member allows the unit cells to be more stably stacked and fixed in the battery module. Examples of the double-sided adhesive member include a double-sided adhesive tape, but is not limited thereto. Preferably, two or more double-sided adhesive members spaced apart from each other may be interposed on one lamination surface. In this case, a predetermined space is secured by the double-sided adhesive members spaced apart between the stacked unit cells, and the separation space functions to buffer a volume change of the unit cell during charge and discharge, and simultaneously generates heat of the unit cell. Help.

The unit cells are stacked so that their electrode leads are oriented in the same direction. Preferably, the electrode cells of the unit cells can be firmly bonded to the unit cells and at the same time facilitate contact of the connection terminals for electrical connection. It may be formed in the through hole, the connecting member connecting the through hole may be a structure coupled to the upper case and the lower case.

The first circuit unit includes connection terminals for connecting unit cells in parallel or in series, and a sensing board assembly for receiving and detecting voltage and / or current signals from each unit cell. Preferably, the first circuit unit receives the voltage signal of the unit cell. The temperature may be measured as the temperature of the entire cell in the sensing board assembly or the main board assembly. The first circuit portion is preferably attached to the side of the module in the electrode lead direction of the unit cell.

The configuration of the connection terminal is not particularly limited as long as it is a structure for connecting unit cells in parallel or in series. Preferably, the connection terminal may have a structure in which a safety device for blocking current when an overcurrent or overheating is connected. Examples of such safety devices include fuses, bimetals, PTC devices, and the like.

The sensing board assembly may be a structure which is preferably made of a PCB and electrically connected to each unit cell.

The second circuit portion may be attached together with the first circuit portion in the electrode lead direction of the unit cell, may be mounted on the lower accommodating portion of the lower substrate, or may be attached to the opposite side of the module opposite the first circuit portion. have. Preferably it is mounted to the lower housing of the lower substrate. In this case, the unit cells are electrically connected to the second circuit unit mounted on the lower housing of the lower case via the first circuit unit, and the operation of the battery is controlled in the main board assembly of the second circuit unit.

The third circuit part, which is the final element of the module connected to an external device and controls overcharge, overdischarge, overcurrent and the like during charging and discharging of the battery, may also be attached to the electrode lead direction of the unit cell together with the first circuit part. It may be mounted on the bottom receiving portion of, or may be attached to the opposite side of the module opposite the first circuit portion. It is preferably attached to opposite sides of the module opposite the first circuit portion. The overcurrent control at the time of charging and discharging can be preferably performed by a switching element such as a FET included in the third circuit section.

In the above, some or all of the circuit parts may have a merged structure, and most preferably, the second circuit part may be mounted on the lower housing part of the lower substrate, and the third circuit part may be disposed on the opposite side part of the module opposite the first circuit part. It is made of attached structure. In this case, in the battery module according to the present invention, circuit parts related to operation of the battery are connected in a form in which the module is wrapped so that the overall size of the module is greatly reduced.

The battery module according to the present invention can be preferably used in a medium-to-large battery system of high output large capacity, the range of the high output large capacity is not particularly limited.

For example, the battery according to the present invention can be used as a power source for various fields and products, including power sources of vehicles such as electric bicycles, electric motorcycles, electric vehicles, hybrid electric vehicles, and the like. The battery module according to the present invention is particularly preferable as a power source of an electric bicycle due to its compact structure and the like.

In the following, with reference to the drawings according to embodiments of the present invention in more detail, this is to help the understanding of the present invention, the scope of the present invention is not limited thereto.

1 and 2 schematically show a perspective view and a side view of a battery module according to an embodiment of the present invention.

1 and 2, the battery module 100 includes an upper case 200, a lower case 300, a plurality of unit cells 400, a first circuit part 500, and a second circuit part (not shown). Not included) and the third circuit unit 700. The unit cells 400 are stacked between the upper case 200 and the lower case 300 which are separated from each other, the first circuit unit 500 is located in front of the battery module 100, the second circuit unit is the bottom surface The third circuit unit 700 is located at the rear side.

Since the upper case 200 and the lower case 300 are separated, the number of unit cells 400 that can be stacked is not limited thereto, and according to the number of stacked units of the unit cells 400, the first circuit unit 500 may be used. ) And only the third circuit unit 700 can be easily designed, the battery module 100 of the desired capacitance and output. In addition, since the unit cells 400 are exposed, heat dissipation of the unit cells 400 may be efficiently performed during charging and discharging.                     

3A illustrates a top perspective view of a lower case and a unit cell in the battery module of FIG. 1, and FIG. 3B illustrates a bottom perspective view of a bottom case with a second circuit unit mounted thereon.

First, referring to FIG. 3A, the lower case 300 is a rectangular structure substantially corresponding to the outer shape of the unit cell 400 and includes an upper accommodating part 310 in which the unit cell 400 is accommodated. The lower case 300 is a member of high strength and electrical insulation, and is preferably made of plastic resin such as ABS (Acrylonitrile-Butadiene-Styrene), PC (polycarbonate), PBT (Polybutylene Terephthalate), and the like.

In the pouch type secondary battery 400 stacked on the lower case 300, the positive lead 420 and the negative lead 430 protrude from the top of the battery body 410, respectively. Through-holes 440 are perforated in the electrode leads 420 and 430 so that a separate connection member, for example, a fastener 800, is formed in a state in which a plurality of unit cells 400 and 401 are stacked. It is inserted into the 440 and can be fixed using a nut (not shown) or the like at its bottom surface through the fixing groove 320 on the lower case 300.

An insulating member 900 is mounted on the electrode leads 420 and 430 to electrically insulate between the unit cells 400 and 401, and the through hole 440 of the electrode leads 420 and 430 is provided in the insulating member 900. ) Is a projection 910 to be fastened. A through hole 920 is formed in the protrusion 910 such that the fastener 800 passing through the through hole 920 of the protrusion 910 may be electrically insulated from the electrode leads 420 and 430. give.

In addition, two double-sided adhesive tapes 1000 are attached to the main body 410 of the unit cell 400 to further ensure stable coupling with the unit cells 410 stacked. Furthermore, since the stacked unit cells 400 and 401 are spaced apart by the thickness of the double-sided adhesive tape 1000, such spaced grooves buffer the volume change of the unit cells 400 and 401 during charging and discharging. It is possible to effectively dissipate heat generated by the batteries 400 and 410.

As shown in FIG. 3B, the lower case 300 has a second circuit part 600 mounted to the lower housing part 330, for energizing the positive electrode and the negative electrode from the first circuit part 500. Wires 340 and 342 are wired to be connected to the third circuit unit 700. In addition, wires 610 and 612 for electrically connecting the sensing board assembly 510 of the first circuit unit 500 and the third circuit unit 700 are also wired. The second circuit portion 600 is sealed with a cover 620 to protect it from the outside.

4 is a perspective view of the lower surface of the upper case used in the battery module of FIG.

Referring to FIG. 4, the upper case 200 has a lower accommodating portion 210 corresponding to its size so that the upper end of the unit cell 400 of FIG. 3A may be coated, and the unit cell 400 electrode. The hole 220 is drilled at a position corresponding to the through hole of the lead.

The upper case 200 may be made of an insulating member that is the same as or different from the lower case 300, and is preferably made of the same plastic resin as the lower case 300.

In the above described the present invention with reference to the drawings according to an embodiment of the present invention, those skilled in the art to which the present invention based on the above various applications and modifications within the scope of the present invention It will be possible.

As described above, the battery module according to the present invention can be easily expanded and contracted flexibly according to a desired electric capacity and output, can stably perform electrical connection between unit cells, and mount the elements constituting the battery module. The wiring for the electrical connection and the like can be made compact, and the mounting of the unit cells in the module can be realized in a simple manner and the heat dissipation is designed to be efficient. Therefore, the battery module of the present invention may be variously applied to medium and large battery modules such as an electric bicycle, an electric vehicle, a hybrid electric vehicle, and the like.

Claims (18)

A module that electrically connects a plurality of unit cells to charge and discharge high-power large-capacity electricity, and includes a plate on which a plurality of unit cells, which are chargeable and dischargeable, are stacked, and a circuit part for controlling operation of the battery. And the plate has a case structure in which an accommodating part corresponding to the size of the unit cell is formed to facilitate mounting of the unit cells. delete The secondary battery module of claim 1, wherein the case has a separate structure covering upper and lower portions of stacked unit cells, respectively. The method of claim 3, wherein A rectangular lower case including an upper accommodating portion in which the unit cells are sequentially stacked; A rectangular upper case including a lower accommodating part covering an upper end of unit cells stacked on the lower case; A first circuit portion including a sensing board assembly for electrically connecting the stacked unit cells and detecting (i) voltage, or (ii) current, or (iii) voltage and current of the battery; A second circuit portion electrically connected to the first circuit portion and including a main board assembly for controlling a module; And A third circuit portion electrically connected to the second circuit portion and connected to an external output terminal while preventing overcurrent; Secondary battery module is configured to include. The secondary battery module of claim 1, wherein the unit battery is a lithium secondary battery. The secondary battery module according to claim 5, wherein the lithium secondary battery is a pouch type battery. The secondary battery module of claim 1, wherein a double-sided adhesive member is interposed between the unit cells. The secondary battery module according to claim 7, wherein two or more double-sided adhesive members spaced apart from each other are interposed on one stacking surface. The secondary battery module of claim 1, wherein a through hole is formed in an electrode lead of the unit cells, and a connection member connecting the through hole is coupled to an upper case and a lower case. 10. The method of claim 9, wherein the insulating member is mounted on the electrode lead between the unit cells for electrical insulation, the insulating member is formed with a projection through which the through hole of the electrode lead can be fastened, the protrusion is an electrode Secondary battery module, characterized in that the through-hole is formed through which the connecting member passing through the through-hole of the lead is formed. The method of claim 4, wherein the first circuit unit comprises a connection terminal for connecting the unit cells in parallel or in series and a sensing board assembly for receiving a voltage and current signal from each unit cell and detecting the temperature of the battery; Secondary battery module characterized in that. The secondary battery module according to claim 11, wherein a safety device is arranged between the connection terminals to cut off a current when an overcurrent or overheat occurs. The secondary battery module of claim 4, wherein the first circuit unit is attached to a side surface of the module in an electrode lead direction of unit cells. The secondary battery module of claim 4, wherein the second circuit unit is mounted to a lower housing of the lower substrate. The secondary battery module according to claim 4, wherein the third circuit portion is attached to an opposite side surface of the module opposite to the electrode lead. The secondary battery module according to claim 4, wherein the third circuit unit includes a switching element that controls overcurrent during charging and discharging. The secondary battery module of claim 1, wherein the module is used as a power source for an electric bicycle, an electric motorcycle, an electric vehicle, and a hybrid electric vehicle. The secondary battery module of claim 1, wherein the module is used as a power source of an electric bicycle.

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