KR101715698B1 - Battery module comprising heat transfer device using wick for cooling part - Google Patents

Abstract

A battery module capable of reducing the temperature deviation of the battery cell and improving the cooling efficiency in spite of a compact structure without using many members is provided. A battery module according to the present invention comprises: a battery cell laminate in which battery cells are stacked; And a plate type heat transfer device that is in thermal contact with the battery cells on at least one side of the battery cell stack. The plate-type heat transfer device may include a case having a sealed structure, a coolant injected into the case to cause a phase change by heat, and a coolant contactable with at least a part of the inner surface of the case to absorb the coolant, Wherein the refrigerant fills at least a part of the space formed inside the case and is evaporated by the heat generated in the battery cell stack and condensed in the wick And moves along the wick to circulate in the space to perform heat transfer.

Description

[0001] The present invention relates to a battery module having a heat transfer device using a wick as a cooling member,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a battery module, a battery pack and a device including the battery module, and more particularly to a battery module including a battery module including a positive electrode plate, a separator and a negative electrode plate, A battery pack and a device including the battery module.

BACKGROUND ART [0002] In recent years, rechargeable secondary batteries have been widely used as energy sources for wireless mobile devices. Also, the secondary battery is attracting attention as a power source for an electric vehicle (EV) and a hybrid electric vehicle (HEV), which are suggested as solutions for air pollution of existing gasoline vehicles and diesel vehicles using fossil fuels .

BACKGROUND ART A middle- or large-sized device such as an automobile uses a battery module in which a plurality of battery cells are electrically connected and a middle- or large-sized battery pack including the same as a unit module due to the necessity of a high output large capacity. Since the battery module and the battery pack are preferably manufactured with a small size and a weight, a prismatic battery, a pouch-shaped battery, or the like, which can be stacked at a high density and have a small weight to capacity ratio, are mainly used as unit cells of a battery module. Particularly, a pouch-shaped battery using an aluminum laminate sheet or the like as an exterior member has attracted much attention due to its advantages such as small weight, low manufacturing cost, and easy shape deformation.

The battery cells constituting the battery module generate a large amount of heat during the charging and discharging process. Particularly, a laminate sheet of a pouch-type battery widely used for a high-output large-capacity battery module and a battery pack is coated with a polymer material having a low thermal conductivity, so that it is difficult to effectively cool the entire battery cell. If the heat of the battery module generated during the charging and discharging process can not be effectively removed, heat accumulation may occur, thereby accelerating the deterioration of the battery module and possibly causing ignition or explosion. Therefore, a cooling member for cooling the battery cells built in the high-power, large-capacity battery module and the battery pack in which the battery module is mounted is necessarily required.

Generally, a battery module is manufactured by stacking a plurality of battery cells at a high density, and adjacent battery cells are stacked at a predetermined interval so as to remove heat generated during charging and discharging. For example, the battery cells themselves may be sequentially stacked while being spaced apart from each other by a predetermined space, or in the case of a battery cell having low mechanical rigidity, one or a combination of two or more batteries may be built in a cartridge or the like. The battery module can be configured. The stacked battery cells or the battery modules have a structure in which a coolant flow path such as cooling water is formed between the battery cells or the battery modules so as to effectively remove accumulated heat.

As one of various methods of releasing heat generated in a secondary battery, Korean Patent Laid-Open Publication No. 10-2013-0062056 discloses a cooling method using cooling water. However, this structure has a problem that the total size of the battery module is increased because a plurality of refrigerant flow paths must be secured corresponding to a plurality of battery cells. In addition, as the number of battery cells is increased, the number of parts (tanks, valves, pumps, coolers, etc.) is increased in relation to the cooling structure to increase the volume of the battery module. And the manufacturing cost is increased accordingly. Further, since the structure in which the refrigerant flowing in the cooling channel flows into the inlet and then exits to the outlet is used, there is a problem that the side closer to the inlet side is cooled more and the side closer to the outlet side is less cooled. That is, there is a problem that the cooling water efficiency increases as the temperature of the cooling water increases as it is far from the inlet and closer to the outlet. This causes a temperature deviation of the secondary battery, and a temperature deviation of the secondary battery leads to a performance deviation of the secondary battery, leading to a deterioration of the performance of the system.

Accordingly, there is a high need for a battery module that can be manufactured in a simple and compact structure while providing a high output large capacity power, and has excellent life characteristics and safety due to high cooling efficiency.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a battery module capable of reducing temperature variation of a battery cell and improving cooling efficiency despite a compact structure without using many members.

Another object of the present invention is to provide a battery pack including the battery module as a unit module and a device including the battery pack.

According to an aspect of the present invention, there is provided a battery module including: a battery cell stack body in which battery cells are stacked; And a plate type heat transfer device that is in thermal contact with the battery cells on at least one side of the battery cell stack. The plate-type heat transfer device may include a case having a sealed structure, a coolant injected into the case to cause a phase change by heat, and a coolant contactable with at least a part of the inner surface of the case to absorb the coolant, Wherein the refrigerant fills at least a part of the space formed inside the case and is evaporated by the heat generated in the battery cell stack and condensed in the wick And moves along the wick to circulate in the space to perform heat transfer.

The case includes an upper plate and a lower plate, and the wick may be positioned to contact the inner wall of the upper plate. The wick is preferably positioned to a side wall perpendicular to the upper plate. It is preferable that the refrigerant is water and the wick is chemically and hydrophilically treated on its surface to absorb water. The upper and lower plates may be made of metal, polymer, silicon or a non-ferrous metal material. The case may further include a plurality of groove patterns acting as a movement channel of the refrigerant on the inner wall surface, and the case may further include a radiating fin for condensing the refrigerant.

The battery module according to the present invention may further include a cooling plate interposed between the battery cell stack and the plate type heat transfer device, and may further include a thermal pad.

The present invention further includes cooling fins interposed at an interface of the battery cells and having ends protruding from one side or both sides of the battery cell stack body, May be mounted.

The structure of the cooling fin is not particularly limited as long as it is a thin member having thermal conductivity. For example, a sheet of a metal material can be preferably used. The metal material may be aluminum or aluminum alloy having high thermal conductivity and light weight among metals, but is not limited thereto.

The positive electrode terminal and the negative electrode terminal protrude from one side of the outer circumferential surface of the battery cell or the positive electrode terminal protrudes from one side of the outer circumferential surface and the negative electrode terminal protrudes from the opposite side of the outer circumferential surface, And the end portion may protrude in a direction perpendicular to the direction in which the light emitting diode is turned.

The cooling plate may further include a cooling plate interposed between the projecting end of the cooling fins and the plate type heat transfer device. In this case, the cooling pad may further include a thermal pad interposed between the cooling plate and the projecting end of the cooling fins.

The protruding end of the cooling fins may be bent to be in close contact with the cooling plate. Specifically, the ends of the protruding cooling fins may be bent at an angle of about 90 degrees and brought into close contact with the cooling plate.

The cooling plate preferably includes at least one of copper, gold, silver, aluminum nitride (AlN), silicon carbide (SiC), and aluminum. Further, the cooling plate may be an air-cooled member having a structure maximizing a contact surface with air or may be formed so as to form an air passage.

In one specific example, the battery cell is preferably a plate-shaped battery cell so as to provide a high laminating ratio in a limited space, and a battery cell laminate is formed by stacking the battery cells so that one surface or both surfaces of the battery cell face each other . Particularly, the plate-shaped battery cell may be a pouch-shaped battery cell having a structure in which an outer periphery of a battery case is thermally fused and sealed while an electrode assembly is embedded in a battery case of a laminate sheet including a resin layer and a metal layer. In this case, the outer circumferential surface of the pouch-shaped battery cell may be fixed between the cartridges forming the battery cell stack by fixing the battery cells.

Specifically, the plate-shaped battery cell is a pouch-shaped battery cell in which an electrode assembly composed of a positive electrode plate, a separator, and a negative electrode plate is sealed inside a battery case together with an electrolyte, and is a plate-shaped battery cell having a generally rectangular parallelepiped structure . Such a pouch-shaped battery cell is generally composed of a pouch-shaped battery case, and the battery case includes an outer covering layer made of a polymer resin having excellent durability, a barrier layer made of a metal material exhibiting barrier properties against moisture, air, And an inner sealant layer made of a polymer resin that can be fused. The battery case of the pouch-shaped battery cell may have various structures.

The battery cell may be a secondary battery capable of providing a high voltage and a high current when the battery module and the battery pack are constructed. For example, the battery cell may be a lithium secondary battery having a large energy storage amount per volume.

The present invention also provides a battery pack including the battery module as a unit module.

The battery pack may be manufactured by assembling the battery module as a unit module according to a desired output and capacity. In consideration of mounting efficiency and structural stability, an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, A storage device, etc., but the scope of application is not limited thereto.

Accordingly, the present invention provides a device comprising the battery pack as a power source, and the device can be specifically an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle or a power storage device.

The structure and manufacturing method of such a device are well known in the art, so a detailed description thereof will be omitted herein.

According to the present invention, a refrigerant is spontaneously circulated by causing a phase change of a refrigerant in a plate-type heat transfer device, so that a cooling system for efficiently cooling the battery cell upon heat generation can be constructed. According to the present invention, since the plate-like heat transfer device is in thermal contact with a plurality of battery cells, the total size of the battery module is not increased and no parts are added, compared with a case where a plurality of refrigerant channels are secured for each battery cell. It does not get complicated. In addition, since all of the battery cells are cooled collectively, no temperature variation is caused.

Accordingly, by circulating the refrigerant without causing an increase in the size of the battery module, the heat accumulated in the inside is dispersed to the outside, thereby providing a uniform cooling effect with a compact cooling structure, so that the temperature deviation of the battery cell and the performance There is an effect of improving the safety against ignition or explosion by lowering the deviation and improving the cooling efficiency.

Particularly, the battery module according to the present invention includes a structure in which the cooling fin is cooled by the plate type heat transfer device during the heat generation of the battery cells through the cooling fin between the battery cells, so that the cooling efficiency can be improved with a simple cooling structure.

Therefore, the battery module according to the present invention can be manufactured in a simple and compact structure while providing a high power, large capacity, and can be expanded to a battery module, a battery pack, and a device having excellent life characteristics and safety due to high cooling efficiency Do.

1 schematically illustrates a battery module according to an embodiment of the present invention.
FIG. 2 is a cross-sectional view schematically showing a plate-type heat transfer device usable in a battery module according to the present invention.
3 schematically shows a battery module according to another embodiment of the present invention.
4 is an exploded perspective view of a battery module according to another embodiment of the present invention.
FIG. 5 is a schematic cross-sectional view taken along a cross section across battery cells in the battery module shown in FIG. 4;

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. It is provided to let you know. It should be noted that 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 are not intended to represent all of the technical ideas of the present invention so that various equivalents And variations are possible.

1 schematically shows a battery module according to the present invention.

Referring to FIG. 1, a battery module 100 according to the present invention includes a battery cell stack 30 and a plate-type heat transfer device 60.

The battery cell stack body 30 is formed by stacking the battery cells 10. The battery cell 10 is preferably a plate-shaped battery cell so as to provide a high lamination ratio in a limited space. The battery cell 10 is stacked so that one surface or both surfaces of the battery cell 10 are opposed to adjacent battery cells 10, Can be formed.

The battery cell 10 includes an electrode assembly composed of a positive electrode plate, a separator and a negative electrode plate. The positive electrode lead and the negative electrode lead are electrically connected to a plurality of positive electrode tabs and negative electrode tabs protruding from the positive electrode plate and the negative electrode plate of each battery cell 10, .

As the material of the positive electrode plate, aluminum is mainly used. Alternatively, the positive electrode plate may be formed by surface-treating a surface of stainless steel, nickel, titanium or aluminum or stainless steel with carbon, nickel, titanium, silver or the like. Further, if the secondary battery is made of a material having high conductivity without causing a chemical change, there is no limitation to use it as a positive electrode plate.

A positive electrode tab may be provided on a part of the positive electrode plate, and the positive electrode tab may be formed to extend the positive electrode plate. Alternatively, it is also possible to form a configuration in which a member made of a conductive material is joined to a predetermined portion of the positive electrode plate through welding or the like. Further, the positive electrode material may be applied and dried on a part of the outer surface of the positive electrode plate to form the positive electrode tab.

The negative electrode plate corresponding to the positive electrode plate is mainly made of a copper material. Alternatively, the cathode plate may be a surface treated with carbon, nickel, titanium or silver on the surface of stainless steel, aluminum, nickel, titanium, copper or stainless steel, and aluminum-cadmium alloy or the like may be used.

The negative electrode plate may also be provided with a negative electrode tab in a certain area and may be formed to extend from the negative electrode plate as in the positive electrode tab described above. In addition, the negative electrode plate may be formed by welding a conductive member to a predetermined portion of the negative electrode plate Or it may be formed in such a manner that a negative electrode material is applied and dried on a part of the outer circumferential surface of the negative electrode plate.

The positive electrode lead is electrically connected to the positive electrode tab provided on the positive electrode plate, and the negative electrode lead is electrically connected to the negative electrode tab provided on the negative electrode plate. Preferably, the positive electrode lead and the negative electrode lead are bonded to a plurality of positive electrode tabs and a plurality of negative electrode tabs, respectively.

The positive electrode plate and the negative electrode plate are respectively coated with a positive electrode active material and a negative electrode active material. LiCoO ₂ , LiNiO ₂ , LiMnO ₂ , LiMn ₂ O ₄ , LiFePO ₄ or Li _{1 + z} Ni _{1 -xy} Co _x M _y O ₂ (0? 1, 0? y? 1, 0? x + y? 1, 0? z? 1, and M is a metal such as Al, Sr, Mg, La, or Mn). The negative electrode active material is a carbonaceous active material, and examples of the negative electrode active material include a carbon material such as crystalline carbon, amorphous carbon, carbon composite, carbon fiber, lithium metal, lithium alloy and the like. The types and chemical compositions of the cathode active material and the anode active material may vary depending on the kind of the secondary battery. Therefore, it should be understood that the specific examples given above are only examples.

The separation membrane is not particularly limited as long as it has a porous material. The separation membrane may be a porous polymer membrane such as a porous polyolefin membrane, polyvinylidene fluoride-hexafluoropropylene, polyvinylidene fluoride-trichlorethylene, polymethyl methacrylate, polyacrylonitrile, polyvinyl Polyvinyl pyrrolidone, polyvinyl acetate, ethylene vinyl acetate copolymer, polyethylene oxide, cellulose acetate, cellulose acetate butyrate, cellulose acetate propionate, cyanoethylpullulan, cyanoethylpolyvinyl alcohol, cyanoethylcellulose, Polybutylene terephthalate, polybutylene terephthalate, polyester, polyacetal, polyamide, polyether ether ketone, polyether sulfone, polyether sulfone, polyether sulfone, , Poly Alkenylene may be formed of oxide, polyphenylene sulfide, polyethylene naphthalene, a non-woven film, a porous web (web) or a mixture film having a structure like. An inorganic particle may be adhered to an end surface or both surfaces of the separator.

The inorganic particles are preferably inorganic particles having a high dielectric constant of 5 or more, more preferably inorganic particles having a dielectric constant of 10 or more and a low density. This is because it can easily transfer lithium ions moving in the cell. Non-limiting examples of inorganic particles having a high dielectric constant of 5 or more is _{Pb (Zr, Ti) O 3} (PZT), Pb 1 - x La x Zr 1 -y Ti y O 3 (PLZT), Pb (Mg 3 Nb _{2/3) O 3 -PbTiO 3} (PMN-PT), BaTiO 3, HfO 2, SrTiO 3, TiO 2, Al 2 O 3, ZrO 2, SnO 2, CeO 2, MgO, CaO, ZnO, Y 2 O ₃ Or a mixture thereof.

The battery cell stack 30 may have a structure in which a plurality of battery cells 10 are simply stacked with an insulating film interposed between the battery cells 10. Alternatively, the battery cell stack 30 may be formed by arranging the battery cells 10 at appropriate intervals on the top and / or bottom of the insulating film, then folding the insulating film together with the battery cell 10 in one direction, And the battery cell 10 is inserted between the stacked structure. As another example, the battery cell stack 30 may be a pouch-shaped battery assembly.

The plate-type heat transfer device 60 has a structure in which the principle of the heat pipe is applied, and the refrigerant is spontaneously circulated by causing a phase change of the refrigerant. In other words, in the present invention, the refrigerant is not forcibly circulated by a pump, etc., and is characterized in that the refrigerant is spontaneously vaporized by the heat generated in the battery cell stack body 30, and then condensed and circulated therein. This cooling method is a cooling method that does not require a mechanical operating part, unlike forced cooling. The refrigerant circulated in the plate-shaped heat transfer device 60 absorbs heat generated in the battery cell stack body 30 and is vaporized and discharged to the outside through a phase change process in which the refrigerant is condensed. Thus, the specific battery cell 10 is excessively heated, It is possible to prevent the heat generated from the battery cell 10 from accumulating in the battery module 100. The refrigerant circulates between the evaporator (close to the battery cell stack 30) and the condenser (near the outside air) and is continuously supplied from the condenser to the evaporator by capillary force, The vapor generated by the battery cell stack 30 is transferred to the condenser and is again converted into the liquid phase.

2 is a cross-sectional view schematically showing a plate-type heat transfer device 60 'that can be used in a battery module according to the present invention. Since the heat transfer device 60 'is plate-shaped, it is easy to mount it on one side of the battery cell stack body 30.

Referring to FIG. 2, a plate type heat transfer device 60 'includes a case 61 having a sealed structure and a refrigerant 62 injected into the case 61 to cause a phase change by heat. The refrigerant may be any conventional refrigerant used in the manufacture of a cooling device. Examples of such a refrigerant include ammonia, acetone, methanol, ethanol and the like, and water may also be used. The plate-shaped heat transfer device 60 'includes a wick 63 that provides a passage for the refrigerant. The wick 63 can circulate the refrigerant by the capillary force, can be a flexible porous material, and can be fabricated into a plurality of minute unit fiber aggregate structures to form a porous capillary. The wick 63 assists in the liquefaction of the vaporized refrigerant and also serves as a flow path. The wick 63 is formed in itself and the micro passages for generating the capillary force are uniformly And the reproducibility in the degree of heat transfer is not deteriorated desirable. If the micro-passages are uniform, the flow resistance does not increase and a high capillary force can be obtained, and even if the evaporation near the heat source becomes active, the flow of the liquid-phase refrigerant is not interrupted. It is important to secure a micro passage of the wick 63 so that this will not occur because dry out of the liquid coolant supply to the evaporator causes a fatal cooling failure. The wick 63 may be a woven or nonwoven web of natural fibers such as cotton, chemical fibers such as polyamides or inorganic fibers such as carbon fibers or webs or fabrics, fabric. < / RTI >

In the plate type heat transfer device 60 ', the refrigerant 62 fills at least a part of the space formed in the case 61 and is vaporized by the heat generated in the battery cell stack 30 to be discharged from the wick 63 Condensed and moved along the wick 63 to circulate in the space to perform heat transfer.

The case includes an upper plate 61a and a lower plate 61b, and the wick 63 may be positioned in contact with the inner wall of the upper plate 61a. It is preferable that the wick 63 is located up to the inner wall of the side surface 61c perpendicular to the upper plate 61a. The wick 63 located up to the inner wall of the side surface 61c can serve as a guide for allowing the condensed refrigerant to travel to the lower plate 61b through the inner wall of the side wall 61c and to circulate the refrigerant. The refrigerant 62 may be water and the wick 63 may be made of a material capable of absorbing and retaining refrigerant such as water or the like and may be chemically and hydrophilically treated to absorb water It may be good. Thus, if the internal components are made of a material capable of absorbing water, it is possible to eliminate the possibility of dry-out.

The upper plate 61a and the lower plate 61b may be made of metal, polymer, silicon or a non-ferrous material. For example, a metal such as copper, aluminum, or titanium. For example, polymers such as plastic, metalized plastic, and plastic combinations. It may be a non-ferrous metal material such as graphite. If necessary, the case 61 may be one whose surface is coated with a polymer material. The case 61 may further include a plurality of groove patterns acting as a movement channel of the refrigerant 62 on the inner wall surface. In this way, when the case 61 is formed with a fine groove pattern on the inner wall surface, the refrigerant can be supplied by the capillary force even through the groove pattern, so that the plate heat transfer device 60 'having higher reliability can be realized.

The plate-like heat transfer device 60 'can be manufactured by the following method.

For example, after attaching the wick 63 to the inner wall of the upper plate 61a, the upper plate 61a and the lower plate 61b are engaged while applying pressure while the upper plate 61a and the lower plate 61b are in contact with each other. A method of welding or clamping the rims of the upper plate 61a and the lower plate 61b may be used. TIG welding, plasma welding, seam welding, high frequency welding, etc. may be used as the welding method. Thereafter, a space formed between the upper plate 61a and the lower plate 61b is set to a low pressure state, a part of the space is filled with liquid refrigerant, and the space is sealed with the outside.

Other methods are possible. For example, a wick 63 having a refrigerant itself (for example, impregnated with a coolant) is attached to the inner wall of the upper plate 61a, and the upper plate 61a and the lower plate 61b are put in contact with each other, 61a and the lower plate 61b. Thereafter, a space formed between the upper plate 61a and the lower plate 61b is set to a low pressure state, and the space is sealed with the outside.

Such a plate type heat transfer device 60 'is a structure that can achieve high productivity and low production cost in mass production due to simple manufacturing and low defective rate, has a high refrigerant supply performance by high capillary force, This is a highly reliable structure with little impact. Additional components such as a tank, a valve, a pump, and a cooler are not required as compared with the conventional cooling member, so that the structure of the battery module 100 and the operation of the cooling system are greatly simplified.

In order to cool the refrigerant whose temperature has risen, a heat radiation member adjacent to and connected to the plate heat transfer device 60 'may be additionally provided. It is preferable that at least a part of the heat dissipating member is provided so as to be exposed to the outer surface of the case 61 and emits heat to the outside of the case 61. The heat dissipating member may have a structure in which a heat dissipation fin or a heat dissipating plate is formed at a portion exposed to the outer surface of the case 61 to increase the cross-sectional area of the heat dissipating member in contact with the outside air to improve the cooling efficiency. In the structure shown in FIG. 2, the case 61 further includes a radiating fin 64 for condensing the refrigerant 62. It is preferable that the heat dissipation fins 64 are formed on the side of the upper plate 61a on which the wicks 63 are provided so as to increase the heat exchange area. The heat exchange area is further enlarged by the radiating fins 64, and the heat exchange performance as a whole can be greatly improved. It is preferable that the lower plate 61b of the plate heat transfer device 60 'used in the present invention can be in thermal contact with the battery cells 10.

The plate-type heat transfer device 60 'in FIG. 2 is an example of the plate-type heat transfer device 60 included in the battery module 100 shown in FIG. 1, and if the refrigerant is spontaneously vaporized, condensed and circulated, May be included in the battery module 100 shown in Fig.

As described above, in the battery module 100, since the plate-shaped heat transfer device 60 is in thermal contact with the plurality of battery cells 10, the total size of the battery module 100 There is no increase in parts, and the manufacturing process is not complicated. In addition, since all the battery cells 10 are cooled collectively, no temperature variation is caused. Since the structure of the plate-like heat transfer device 60 is simple and there is no additional accessory device, it is possible to manufacture the battery module 100 which is very compact. Thus, the available space of the system is secured.

The plate-type heat transfer device 60 generates spontaneous refrigerant circulation in the closed space and has a structure of no refrigerant, thereby realizing a stable cooling system. Since the plate-type heat transfer device 60 has a simple structure and does not have an additional auxiliary device, the battery cell 10 is circulated by circulating the refrigerant and dispersing the heat accumulated therein, without causing the size of the battery module 100 to increase, It is possible to protect the safety of the user from an accident caused by malfunction of the battery module 100 and to prevent the life of the battery cells 10 from being shortened, And the reliability can be greatly improved.

3 schematically shows a battery module according to another embodiment of the present invention.

The battery module 100 'shown in FIG. 3 is a modified example of the battery module 100 shown in FIG. 1 and includes a cooling plate 70 and a thermal plate 70 between the battery cell stack 30 and the plate- And the pad 80 is further included.

According to the above structure, the heat generated in the battery cell stack 30 is transferred to the plate-type heat exchanger 60 through the cooling plate 70, and the heat is discharged to the outside according to the spontaneous circulation of the refrigerant .

The cooling plate 70 functions to transfer the heat generated from the battery cell stack 30 to the plate type heat transfer device 60 and is preferably made of a material having a high thermal conductivity for more efficient heat transfer . The material of the cooling plate 70 is not particularly limited as long as it is a thermally conductive member, for example, a metal material can be preferably used. The metal material may be aluminum or aluminum alloy having high thermal conductivity and light weight among metals, but is not limited thereto. Specifically, the cooling plate 70 may include at least one of copper, gold, silver, aluminum nitride, silicon carbide, and aluminum.

Table 1 below shows the thermal conductivity of each material capable of forming the cooling plate 70 and has a thermal conductivity of about 400 W / m.K for copper, for example, as shown in Table 1. Accordingly, when the cooling plate 70 is made of copper, the heat generated in the battery cell stack 30 can be rapidly transferred to the plate-type heat exchanger 60 during charging and discharging, thereby improving the cooling efficiency.

The thermal pad 80 is a member for efficiently transferring the heat of the battery cell stack 30 to the cooling plate 70 and the plate heat transfer device 60. The thermal pad 80 includes a battery cell stack 30, And the like, to improve the adhesion. As one example, a heat transfer pad in which a thermally conductive material is combined with silicon may be manufactured to have a structure in which both elasticity and thermal conductivity are exerted. The thermal pad (80) is designed to dissipate heat internally, which is used in places where the device generates heat due to the heat generated by the components, and is manufactured by various manufacturers, and a commercially available thermal pad may be purchased and applied. It is preferable to select a thermal pad having excellent thermal conductivity, stretchability, flexibility, and insulation.

FIG. 4 is an exploded perspective view of a battery module according to another embodiment of the present invention, and FIG. 5 is a schematic cross-sectional view taken along a cross section of battery cells in the battery module shown in FIG.

The battery module 200 of FIGS. 4 and 5 is particularly a case where the battery cell 110 is a pouch-shaped battery cell. A pouch-shaped battery cell is a battery cell in which an electrode assembly having a structure of a positive electrode plate, a separator, and a negative electrode plate is sealed inside a battery case together with an electrolyte, and is a plate-shaped battery cell having a generally rectangular parallelepiped structure. Such a pouch-shaped battery cell is generally composed of a pouch-shaped battery case, and the battery case includes an outer covering layer made of a polymer resin having excellent durability, a barrier layer made of a metal material exhibiting barrier properties against moisture, air, And an inner sealant layer made of a polymer resin that can be fused. The case of the pouch type battery cell may have various structures. In this embodiment, the pouch-shaped battery cell may have a structure in which the outer circumferential surface of the battery case is thermally fused and sealed with the electrode assembly embedded in the battery case of the laminate sheet including the resin layer and the metal layer. The outer circumferential surface of the pouch-shaped battery cell may be fixed between the cartridges forming the battery cell stack 130 by fixing the battery cells 110 to each other.

The battery module 200 has a structure including the battery cell stack 130, the cooling plate 170, and the plate-shaped heat transfer device 160 including the pouch-shaped battery cells as the unit battery cells 110. The cooling plate 170 is similar to the cooling plate 70 described with reference to Fig. 4, and particularly as an air-cooled member, may have a structure maximizing the contact surface with air or may be machined to form an air flow path. The plate-shaped heat transfer device 160 is similar to the plate-type heat transfer device 60 described with reference to FIG. 1, and may be a plate-type heat transfer device 60 'described with reference to FIG. 2 in particular.

5, the battery cell stack 130 is interposed in the interface of the battery cells 110, and the cooling fins 130 having ends protruding from one side or both sides of the battery cell stack 130, (120).

As shown in the drawing, the battery cell 110 has a positive terminal protruded on one side of the outer circumferential surface and a negative terminal protruded on the opposite side of the battery cell 110. However, the positive electrode and the negative terminal may protrude from one side of the outer circumferential surface, The fin 120 may protrude in the direction perpendicular to the direction in which the positive and negative terminals are protruded.

The structure of the cooling fin 120 is not particularly limited as long as it is a thin, thermally conductive member, for example, a sheet of a metal material can be preferably used. The metal material may be aluminum or aluminum alloy having high thermal conductivity and light weight among metals, but is not limited thereto.

The plate heat transfer device 160 is disposed at the protruding end of the cooling fin 120 with the cooling plate 170 interposed therebetween so that the battery cell stack 130 is formed of the battery cells 110 and the plate heat exchanger 160, Can be contacted.

The projecting ends of the cooling fins 120 are bent so as to be in close contact with the cooling plate 170. Specifically, the ends of the protruding cooling fins 120 may be bent at an angle of about 90 degrees and adhered to the cooling plate 170. [ This structure increases the contact area with the cooling plate 170 to increase the heat conduction efficiency and further improve the cooling effect. As shown in the enlarged view of FIG. 5, the cooling plate 170 is corrugated like a corrugated cardboard so as to form an air flow path with the plate-type heat transfer device 160, thereby enabling efficient heat transfer and cooling.

5, the cooling plate 170 conveys the heat of the battery cells 110 through the cooling fins 120 and conducts the cooling to the plate-type heat transfer device 160 . A thermal pad as described with reference to FIG. 3 may further be provided between the protruding end of the cooling fin 120 and the cooling plate 170.

A heat transfer process will be described in detail with reference to a case where the plate heat transfer device 60 'described with reference to FIG. 2 is employed as the plate heat transfer device 160 of the battery module 200 as an example.

When heat is generated in the battery cells 110, the heat is transferred to the cooling plate 170 through the cooling fins 120 and this heat is also transferred to the lower plate 61b of the plate-like heat transfer device 60 ' . The heat transferred through the lower plate 61b is transferred to the liquid-phase refrigerant 62 to vaporize the liquid-phase refrigerant 62. At this time, the liquid refrigerant 62 vaporizes and absorbs the heat transferred from the battery cells 110. The vaporized gaseous refrigerant rapidly flows in all directions through the space between the lower plate 61b and the upper plate 61a . The gaseous refrigerant flowing into the wick 63 is condensed while being transferred to the outside to be converted into the liquid phase refrigerant 62. The wick 63 moves toward the position where the battery cells 110 are positioned by the capillary force of the wick 63, So as to cool the battery cells 110 quickly and effectively.

The battery module 200 has a structure in which the cooling fin 120 is cooled by the plate heat transfer device 160 during the heat generation of the battery cells 110 through the cooling fin 120 between the battery cells 110 The cooling efficiency can be improved with a simple cooling structure.

As described above, according to the present invention, a battery module can be manufactured in a simple and compact structure while providing high power, large capacity, and excellent lifetime characteristics and safety due to high cooling efficiency. Such a battery module constitutes a battery pack, and the battery pack is mounted in a device using the battery pack, thereby realizing excellent battery performance.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but many variations and modifications may be made without departing from the spirit and scope of the invention as defined in the appended claims. It will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the appended claims.

10, 110 ... battery cells 30, 130 ... battery cell laminate
60, 60 ', 160 ... plate heat transfer device 61 ... case
62 ... refrigerant 63 ... wick
64 ... Radiating fins 70, 170 ... Cooling plate
80 ... Thermal pad 100, 100 ', 200 ... Battery module
120 ... cooling pin

Claims (20)

A battery cell laminate in which battery cells in which positive and negative terminals are protruded on one side of an outer circumferential surface or positive terminals are protruded on one side of an outer circumferential surface and negative terminals are protruded on an opposite side are laminated; And
And a plate type heat transfer device in thermal contact with the battery cells on at least one side of the battery cell stack in a direction perpendicular to a direction in which the positive and negative terminals are projected,
A case having a sealed structure, the case including a lower plate close to the battery cell stack and an upper plate close to the outside air;
A refrigerant injected into the case and causing a phase change by heat; And
And a wick disposed in contact with an inner wall of the upper plate to absorb the refrigerant and to provide a moving passage in a direction parallel to the inner surface of the case of the refrigerant,
The refrigerant fills at least a part of the space formed in the case and is evaporated in the lower plate of the case by the heat generated in the battery cell stack, condensed in the wick, moved along the wick, circulated in the space, Battery module to perform. delete The battery module according to claim 1, wherein the wick is positioned to a side wall perpendicular to the upper plate. The battery module according to claim 1, wherein the coolant is water and the surface of the wick is chemically hydrophilicized to absorb water. The battery module according to claim 1, wherein the upper plate and the lower plate are made of metal, polymer, silicon or a non-ferrous metal material. The battery module according to claim 1, wherein the case further comprises a plurality of groove patterns acting as a movement channel of the refrigerant on the inner wall surface. The battery module according to claim 1, wherein the case further comprises a radiating fin for condensing the refrigerant on the upper plate side. The battery module according to claim 1, further comprising a cooling plate interposed between the battery cell stack body and the plate type heat transfer device. The battery module according to claim 8, further comprising a thermal pad interposed between the battery cell stack and the cooling plate. The battery pack according to claim 1, further comprising cooling fins interposed in an interface between the battery cells, the cooling fins protruding from one side or both sides of the battery cell stack body,
Wherein the plate type heat transfer device is mounted on a protruding end portion of the cooling fins. 11. The battery module according to claim 10, wherein the cooling fin protrudes in a direction perpendicular to a direction in which the positive and negative terminals are protruded. 11. The battery module of claim 10, further comprising a cooling plate interposed between the projecting end of the cooling fins and the plate-type heat transfer device. 13. The battery module according to claim 12, further comprising a thermal pad interposed between the protruding end of the cooling fins and the cooling plate. The battery module according to claim 12, wherein the cooling plate is formed so as to form an air flow path. 13. The battery module according to claim 12, wherein protruding ends of the cooling fins are bent so as to be in close contact with the cooling plate. The battery module according to claim 12, wherein the cooling plate includes at least one of copper, gold, silver, aluminum nitride, silicon carbide, and aluminum. The battery module according to claim 1, wherein the battery cell is a plate-shaped battery cell, and the battery cell stack is formed by stacking the battery cells so that one surface or both surfaces of the battery cell faces the adjacent battery cells. The pouch-shaped battery cell according to claim 17, wherein the plate-shaped battery cell is a pouch-shaped battery cell having a structure in which an outer periphery of a battery case is thermally fused and sealed with an electrode assembly in a battery case of a laminate sheet including a resin layer and a metal layer, Wherein the outer circumferential surface of the pouch-shaped battery cell is thermally fused and fixed between the cartridges forming the battery cell stack by fixing the battery cells to each other. A battery pack comprising the battery module according to any one of claims 1 to 18 as a unit module. A device as claimed in claim 19, characterized in that it is any one of an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device comprising the battery pack according to claim 19.

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