Battery pack with heat dissipation passive cooling structure

Abstract

In one example, the battery pack includes a cell array including a plurality of rectangular cells aligned in a row, a pair of side plates respectively arranged on both sides of the cell array, and a pair of end plates respectively arranged on the front and rear sides of the cell array, with both widthwise ends of the end plates fixed to side brackets provided on both longitudinal ends of the side plates, forming a battery block in which the cell array is constrained into one block, and a pack case in which a plurality of the battery blocks are mounted, and the side plates, end plates, and side brackets are all made of a thermally conductive material and are thus thermally connected to each other.

Description

[Technical field]

[0001] The present invention relates to a battery pack having a heat dissipation passive cooling structure in which all prismatic cells included in a battery block mounted in a battery pack are thermally connected to the entire pack case as well as to other adjacent battery blocks, and a heat capacity around the prismatic cells is maximized, thereby quickly dissipating heat generated in the prismatic cells.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0168740 dated December 6, 2022, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference. [Background technology]

[0003] Unlike primary batteries, secondary batteries can be recharged, and they have been much researched and developed in recent years due to their potential for miniaturization and large capacity. The demand for secondary batteries as an energy source is rapidly increasing due to the increasing technological development and demand for mobile devices, as well as the emergence of electric vehicles and energy storage systems in response to the modern demand for environmental protection.

[0004] Secondary batteries are classified into coin type batteries, cylindrical type batteries, square type batteries, and pouch type batteries according to the shape of the battery case. The electrode assembly installed inside the battery case of the secondary battery is a power generating element capable of charging and discharging, which is made of a laminated structure of electrodes and a separator.

[0005] The secondary battery may be in the form of a battery pack, which is a group of multiple battery cells. The battery pack may be installed in devices that require high energy, such as electric vehicles, by increasing the energy density. The battery pack electrically connects multiple battery cells to output a specified amount of power, cools the battery cells that may become hot during operation, and includes various safety devices to respond to emergency situations such as fire.

[0006] In particular, since secondary batteries are required to be used continuously for long periods of time, it is necessary to effectively control the heat generated during the charging and discharging process.If secondary batteries are not cooled smoothly, a positive feedback chain reaction occurs in which an increase in temperature causes an increase in current, and the increase in current causes another increase in temperature, resulting in a catastrophic state of thermal runaway.

[0007] In addition, when secondary batteries are grouped together in the form of a module or pack, a thermal propagation phenomenon occurs in which thermal runaway in one secondary battery causes other surrounding secondary batteries to continuously overheat. Furthermore, there is a high risk of fire due to ignition sources such as flammable gases released from an overheated secondary battery and heating electrodes, so it is necessary to suppress the risk of such fire.

[0008] In this regard, in order to increase the energy density per unit volume, a structure is required that can more efficiently disperse heat generated in the battery cells during charging and discharging by mounting more battery cells in the same pack space. Summary of the Invention [Problem to be solved by the invention]

[0009] An object of the present invention is to provide a battery pack in which each type of cell constituting the battery pack is thermally connected to a battery block, a battery module, and even a pack case to ensure sufficient thermal capacity, thereby quickly dissipating heat generated in the prismatic cells and effectively suppressing temperature rise.

[0010] However, the technical problem that the present invention aims to solve is not limited to the above-mentioned problem, and other problems not mentioned can be clearly understood by a person skilled in the art from the description of the invention described below. [Means for solving the problem]

[0011] The present invention relates to a battery pack, and in one example, the battery pack includes a cell array including a plurality of rectangular cells aligned in a row, a pair of side plates respectively arranged on both sides of the cell array, and a pair of end plates respectively arranged on the front and rear sides of the cell array, with both widthwise ends of the end plates fixed to side brackets provided on both longitudinal ends of the side plates, thereby constraining the cell array to one block, and a pack case in which a plurality of the battery blocks are mounted, and the side plates, end plates, and side brackets are all made of thermally conductive material and are thus thermally connected to each other.

[0012] The end plate includes an end bracket that is fixed to a mounting portion provided on the pack case.

[0013] The side bracket includes an end bracket that is fixed to a mounting portion provided on the pack case.

[0014] Here, the end bracket, the mounting portion, and the pack case are all made of a thermally conductive material, and are therefore thermally connected to one another.

[0015] In one embodiment of the present invention, the end bracket has a fastening surface parallel to the width direction, and one or more fastening holes are formed in the fastening surface, and the end bracket is fixed to the mounting part through the fastening holes.

[0016] And, the end bracket may include a reinforcing rib perpendicular to the fastening surface.

[0017] The side plate may be a single plate bent in a "U" shape with an open upper end to form a space therein.

[0018] The side plate may have concave surfaces on both sides of the bent plate, the concave surfaces facing each other and joined together along the longitudinal direction of the concave surfaces to form at least one joining rib.

[0019] The side plate includes at least one heat absorption / venting pouch inserted into an internal space defined by the joining rib, and the heat absorption / venting pouch hermetically houses an absorbent material impregnated with a liquid.

[0020] In one embodiment, the absorbent material can be a superabsorbent matrix comprising superabsorbent polymers (SAP) or superabsorbent fibers (SAF).

[0021] The heat absorbing / venting pouch may have a heat seal along its edge, and a weakened portion having a relatively low burst strength on the heat seal.

[0022] Meanwhile, an upper flange is provided at the upper end of the side plate, which is bent so as to contact the upper surface of the cell array, and as the end bracket is fixed to the mounting portion, the upper flange applies a downward fixing force that presses the cell array against the base plate of the pack case.

[0023] The pack case includes a base plate forming a bottom surface, side frames forming walls along all four sides of the base plate, and an upper cover sealing the top surface of the pack case, and a cooling flow path through which a cooling medium flows may be provided inside the base plate.

[0024] A thermally conductive thermal interface material (TIM) may be interposed between contact surfaces of the base plate and the battery block.

[0025] The side bracket may include a fastening groove into which a welding bolt protruding from the end plate is inserted, and the welding bolt and the fastening groove may be joined to each other by welding.

[0026] Preferably, the side bracket may have the fastening grooves on both left and right sides with respect to a center in a width direction of the side plate.

[0027] As a result, another cell array arranged along the width direction shares the side plate, and the welding bolts provided on a pair of end plates arranged on the front and rear surfaces of the another cell array are fixed to the fastening grooves of the side bracket, thereby allowing the multiple cell arrays to be expanded along the width direction. Effect of the Invention

[0028] In the battery pack of the present invention having the above-mentioned configuration, the plates that bind a plurality of rectangular cells to form one battery block, the brackets that attach the battery block to the pack case, and the structure of the pack case are all made of thermally conductive materials and are thermally connected to each other.

[0029] As a result, in the battery pack of the present invention, not only the battery block that restrains the prismatic cell itself, but also the surrounding battery blocks and even the pack case form a single thermal capacity. By securing such a large thermal capacity, it effectively suppresses temperature increases during charging and discharging and embodies a passive cooling structure that quickly dissipates heat even in emergency situations such as thermal runaway and heat propagation.

[0030] However, the technical effects that can be obtained by the present invention are not limited to the effects described above, and other effects not mentioned can be clearly understood by those of ordinary skill in the art from the description of the invention described below.

[0031] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. [Brief description of the drawings]

[0032] [Figure 1] 1 is a view showing a battery block according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded perspective view of the battery block of FIG. 1. [Diagram 3] 1 is a diagram showing a side plate. [Figure 4] FIG. 4 is a cross-sectional view taken along line "AA" in FIG. [Diagram 5] FIG. 4 is a cross-sectional view taken along line "BB" in FIG. 3. [Figure 6] 1 is a view showing a structure in which a battery block is expanded in a width direction; [Figure 7] 1 is a view showing a structure in which a battery block is expanded in a width direction; [Figure 8] 4 is a diagram illustrating an example of a structure in which a battery block is fixed to a pack case according to the present invention; [Figure 9] 4 is a diagram illustrating an example of a structure in which a battery block is fixed to a pack case according to the present invention; [Figure 10] FIG. 4 is a plan view of the battery block, illustrating a structure in which the battery block and the pack case are thermally connected to each other. [Figure 11] 1 is a diagram showing a heat transfer structure between a battery block and a base plate. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be described in detail below.

[0034] However, this is not intended to limit the invention to any particular embodiment, but it should be understood to include all modifications, equivalents, or alternatives falling within the spirit and scope of the invention.

[0035] In the present invention, terms such as "comprise" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and may be understood as not precluding the presence or additional possibility of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0036] In addition, in the present invention, when a layer, film, region, plate, or other portion is described as being "on" another portion, this includes not only the case where it is "directly on" the other portion, but also the case where there is another portion in between. Conversely, when a layer, film, region, plate, or other portion is described as being "under" the other portion, this includes not only the case where it is "directly under" the other portion, but also the case where there is another portion in between. In addition, in the present application, being "on" can include not only the case where it is located at the top, but also the case where it is located at the bottom.

[0037] The present invention relates to a battery pack, and in one example, includes a plurality of battery blocks and a pack case in which the battery blocks are mounted.

[0038] The battery block includes a cell array including a plurality of rectangular cells aligned in a row, a pair of side plates respectively disposed on both side surfaces of the cell array, and a pair of end plates respectively disposed on the front and rear surfaces of the cell array, with both widthwise ends of the end plates fixed to side brackets provided at both longitudinal ends of the side plates, thereby binding the cell array into a single block.

[0039] Here, the side plates, end plates, and side brackets are all made of thermally conductive materials and are therefore thermally connected to each other, and the end plates and / or end brackets provided on the side plates, the mounting portions of the pack case to which the end brackets are fixed, and the pack case are all made of thermally conductive materials and are therefore all thermally connected to each other.

[0040] In the battery pack of the present invention, the prismatic cells and the cell array that is an assembly of these cells are thermally connected to the battery block that binds them, as well as to other surrounding battery blocks and even the pack case. As a result, all structures around any one prismatic cell constitute a single thermal mass. By securing such a large thermal mass, it is possible to effectively suppress temperature increases during charging and discharging, and to realize a passive cooling structure that quickly dissipates heat even in emergency situations such as thermal runaway or heat propagation.

[0041] Hereinafter, specific embodiments of the present invention will be described in detail with reference to the accompanying drawings. Hereinafter, directions such as front-back, up-down, left-right, and right-left directions used to specify relative positions are intended to facilitate understanding of the invention, and unless otherwise specified, are based on directions shown in the drawings.

[0042] (First embodiment) Fig. 1 is a view showing a battery block 10 according to one embodiment of the present invention, and Fig. 2 is an exploded perspective view of the battery block 10 of Fig. 1. The configuration of the battery block 10 mounted in the battery pack 600 of the present invention will be described below first. The description of the configuration of the battery block 10 is useful for understanding the overall configuration of the present invention including the mounting structure of the pack case 602.

[0043] Referring to the accompanying Figures 1 and 2, a battery block 10 according to the present invention includes a pair of side plates 200, a pair of end plates 300 coupled thereto to form a parallelepiped-shaped space, and a cell array 100 accommodated in the parallelepiped space.

[0044] The cell array 100 refers to a cell group consisting of a number of prismatic cells 110 aligned in a row. Each prismatic cell 110 is a completed prismatic secondary battery that can be charged and discharged independently, and in the illustrated embodiment, a cell array 100 is shown as an example in which 12 prismatic cells 110 are assembled together. All the prismatic cells 110 are generally configured to have the same specifications, and the prismatic cells 110 aligned in a row generally form a parallelepiped shape.

[0045] For reference, the illustrated prismatic cell 110 corresponds to a one-way prismatic cell 110 in which positive and negative electrode terminals 112 are all disposed on the upper surface, and a venting device 114 is provided between the pair of electrode terminals 112. The venting device 114 is a device corresponding to a safety valve that bursts when pressure acts inside the prismatic cell 110 to relieve the internal pressure, and may include, for example, a rupture disk made of a thin metal plate member with a notch. When the internal pressure of the sealed prismatic cell 110 increases, the rupture disk generates tensile deformation over the entire thin plate due to the pressure, and the weak notch portion breaks to relieve the internal pressure of the prismatic cell 110.

[0046] The electrode terminals 112 of the prismatic cells 110 on the cell array 100 may be arranged in a row with the same polarity or with opposite polarity alternating for convenience of parallel or serial electrical connection. In other words, the arrangement of a plurality of prismatic cells 110 in a row does not necessarily mean that the polarities of the electrode terminals 112 are aligned in a row.

[0047] A pair of side plates 200 are disposed on both sides of the cell array 100, and a pair of end plates 300 are disposed on the front and rear sides of the cell array 100. Both ends of the end plate 300 in the width direction W are fixed to side brackets 210 provided on both ends of the side plate 200 in the longitudinal direction L, and the cell array 100 is bound into one block by the mutual connection of the end plate 300 and the side plate 200 via the side brackets 210.

[0048] Here, the side plate 200, the end plate 300, and the side bracket 210 connecting them are all made of a thermally conductive material, for example, a metal material with excellent thermal conductivity such as aluminum or stainless steel (SUS), thereby thermally connecting the side plate 200 and the end plate 300. In other words, for a certain prismatic cell 110 on the cell array 100, the other surrounding prismatic cells 110 as well as the side plate 200 and the end plate 300 in contact with the cell array 100 form a single thermal mass that is thermally connected to each other.

[0049] In this way, the entire battery block 10 forms a single thermal capacity, which not only mitigates a sudden increase in temperature of the prismatic cells 110 during charging and discharging, but also provides the basis for a passive cooling structure that quickly dissipates heat in emergency situations such as thermal runaway and heat propagation.

[0050] Fig. 3 is a view showing a side plate 200, and Fig. 4 is a cross-sectional view taken along line "AA" in Fig. 3. The side plate 200 shown in the drawing is made of a single plate bent into a "∪" shape with an open top to form a space inside. By bending the single plate into a "∪" shape with an open top, the side plate 200 is lightweight yet exhibits excellent mechanical strength.

[0051] 3 and 4, the side plate 200 has concave surfaces 222 on both sides of the bent plate, and the facing concave surfaces 222 are joined to each other to form a joining rib 220. At least one such joining rib 220 is provided along the longitudinal direction L of the side plate 200, and in the illustrated embodiment, a total of three joining ribs 220 are formed at both ends and the center of the side plate 200.

[0052] A single plate bent into a "∪" shape has excellent durability and strength against compression and tension in the longitudinal direction L due to the bent structure, but can be relatively vulnerable to forces in the height direction H. The joining rib 220 improves rigidity against forces in the height direction H by bundling the concave surfaces 222 on both sides of the side plate 200 into one by joining them by welding or bundling them by rivets or the like.

[0053] The structure of the side plate 200, i.e., the single plate structure bent into a "u" shape and the structure of the interconnected concave surfaces 222, allows the side plate 200 to have a strong mechanical rigidity while being lightweight. As a result, in the battery block 10 of the present invention, the side plate 200 replaces the cross beam structure provided in the conventional battery pack, and the structure of the battery pack 600 is simplified accordingly, improving the space utilization rate of the battery pack 600, further increasing the energy density per the same volume, and reducing the cost.

[0054] 3 and 5, one or more heat absorption / venting pouches 240 are inserted and built into the side plate 200. That is, a narrow and long space is provided inside the side plate 200 by a pair of concave surfaces 222 that locally form the joining ribs 220, and the heat absorption / venting pouches 240 are inserted into the space. In the illustrated embodiment, a total of three joining ribs 220 are formed at both ends and the center of the side plate 200, creating two partitioned spaces, and one heat absorption / venting pouch 240 is placed in each space.

[0055] The heat absorption / venting pouch 240 contains an absorbent material 242 impregnated with a large amount of liquid, and the liquid impregnated in the absorbent material 242 absorbs the heat of the prismatic cell 110 transferred through the side plate 200. That is, the heat absorption / venting pouch 240 has a heat capacity corresponding to the heat absorption of the liquid impregnated in the absorbent material 242 and the latent heat absorbed as the liquid vaporizes when the liquid exceeds its boiling point. The heat absorption and latent heat of the liquid add a considerable heat capacity to the side plate 200, allowing it to absorb more heat of the prismatic cell 110, further slowing down the temperature rise of the prismatic cell 110.

[0056] The body of the heat absorption / venting pouch 240 may be manufactured using a flexible laminate sheet, and the laminate sheet may have a three-layer structure including an aluminum thin film layer, an inner resin layer formed inside the aluminum thin film layer, and an outer resin layer formed outside the aluminum thin film layer. For example, the inner resin layer may be cast polypropylene (CPP) or polypropylene (PP), and the outer resin layer may be polyethylene terephthalate (PET) or nylon.

[0057] The liquid impregnated in a large amount in the absorbent 242 housed in the heat absorption / venting pouch 240 absorbs heat generated in the prismatic cell 110, and when the temperature exceeds the boiling point and the liquid vaporizes, the liquid changes into gas and the volume increases rapidly, causing internal pressure to act on the heat absorption / venting pouch 240 that seals the absorbent 242. When the internal pressure exceeds the burst strength of the heat absorption / venting pouch 240, a part of the heat absorption / venting pouch 240 breaks and releases steam. This release of steam (venting) cools the high-temperature prismatic cell 110 once again.

[0058] Here, the heat absorption / venting pouch 240 may be configured to suitably guide the position where the steam is discharged so that the discharged steam performs an effective cooling effect. For this purpose, a weakened portion 246 may be provided in a part of the heat-sealed sealing portion 244 formed along the edge of the heat absorption / venting pouch 240. The weakened portion 246 is configured to be broken preferentially due to an increase in internal pressure caused by vaporization of liquid by locally lowering the sealing strength of the heat-sealed sealing portion 244. That is, the weakened portion 246 may be formed in a manner that makes the heat-sealed strength of the heat-sealed sealing portion 244 lower than the surrounding area. For example, the thickness of the weakened portion 246 may be relatively thinner than the surrounding area, or a notch may be formed to reduce the strength, or the weakened portion 246 may be formed by locally removing an aluminum thin film layer that maintains the durability of the laminate sheet.

[0059] Meanwhile, in the first embodiment of the present invention, the absorbent 242 may be a highly absorbent matrix, for example, an absorbent 242 including a highly absorbent polymer (SAP) or a highly absorbent fiber (SAF). The highly absorbent matrix is ​​porous or fibrous and can absorb a large amount of liquid by exhibiting capillary action, and the highly absorbent fiber can be manufactured in the form of fibers such as nonwoven fabric by processing a highly absorbent resin. The highly absorbent matrix can greatly increase the heat capacity of the side plate 200 by the amount of liquid that can be accommodated.

[0060] In the present invention, the specific types of the superabsorbent resin and the superabsorbent fiber produced therefrom are not particularly limited, and any type that has excellent absorption capacity for fluids, especially water, can be used without limitation. In the present invention, examples of the superabsorbent resin include polyacrylic acid, polyacrylates, polyacrylate graft polymers, starch, crosslinked carboxymethyl cellulose, acrylic acid copolymers, hydrolyzed starch-acrylonitrile graft copolymers, starch-acrylic acid graft copolymers, saponified vinyl acetate-acrylic acid ester copolymers, hydrolyzed acrylonitrile copolymers, hydrolyzed acrylamide copolymers, ethylene-maleic anhydride copolymers, isobutylene-maleic anhydride copolymers, polyvinyl sulfonic acid, polyvinyl phosphonic acid, polyvinyl phosphoric acid, polyvinyl sulfuric acid, sulfuric acid, and sulfuric acid. Examples of the crosslinking agent include one or more selected from the group consisting of quaternized polystyrene, polyvinylamine, polydialkylaminoalkyl(meth)acrylamide, polyethyleneimine, polyallylamine, polyallylguanidine, polydimethyldiallylammonium hydroxide, quaternized polystyrene derivatives, guanidine-modified polystyrene, quaternized poly(meth)acrylamide, polyvinylguanidine, and mixtures thereof, and preferably include one or more selected from the group consisting of crosslinked polyacrylates, crosslinked polyacrylic acids, and crosslinked acrylic acid copolymers, but are not limited thereto.

[0061] In the present invention, the type of acrylic acid copolymer used as the superabsorbent resin is not particularly limited, but it may be a copolymer containing an acrylic acid monomer and one or more comonomers selected from the group consisting of maleic acid, itaconic acid, acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, 2-(meth)acryloylethanesulfonic acid, 2-hydroxyethyl (meth)acrylate, and styrenesulfonic acid.

[0062] In the present invention, the highly absorbent resin can have a water absorption capacity of 10 g / g to 500 g / g, preferably 50 g / g to 200 g / g, but is not limited thereto. That is, 1 g of highly absorbent resin can absorb 10 g to 500 g of water, preferably 50 g to 200 g of water.

[0063] In the present invention, the greater the water absorption capacity of the superabsorbent resin, the longer the cooling effect can be maintained; however, if it exceeds 500 g / g, the fluidity of the superabsorbent resin increases and it becomes difficult to maintain its shape, making it impossible to provide effective cooling, and if it is less than 10 g / g, the cooling effect will not last long enough to be inefficient.

[0064] In the first embodiment of the present invention, the liquid impregnated in the absorbent 242 may be water. Water is a substance that has the largest specific heat and latent heat among readily available liquids. Therefore, the water contained in the absorbent 242 absorbs a large amount of heat during the process of changing phase to gas starting before vaporization, and is therefore suitable for application to the heat absorption / venting pouch 240 of the present invention.

[0065] Meanwhile, an upper flange 230 is bent at the upper end of the side plate 200 to contact the upper surface of the cell array 100. The upper flange 230 generates a downward fixing force that presses the cell array 100 to the bottom when the battery block 10 is mounted in the pack case 602. The structure in which the battery block 10 of the present invention is mounted in the pack case 602 will be described in more detail with reference to Figs. 8 and 9 below.

[0066] 1 and 2, side brackets 210 provided on both ends of a side plate 200 have fastening grooves 212 into which weld bolts 310 protruding from an end plate 300 are inserted, and the weld bolts 310 and the fastening grooves 212 are joined to each other by welding.

[0067] Welding bolts 310 provided on a pair of end plates 300 arranged on the front and rear surfaces of the cell array 100 provide fastening points for the side brackets 210, and the assembly positions of the side plates 200 and the end plates 300 are provisionally aligned by fitting the fastening grooves 212 into the welding bolts 310. For stable and firm connection between the side plates 200 and the end plates 300 and for strong restraint on the cell array 100, the welding bolts 310 and the fastening grooves 212 may be provided in pairs, one above and one below, based on the center of the height direction H of the cell array 100.

[0068] 1 to 3, the end plate 300 includes an end bracket 400 that is fixed to the pack case 602. The side bracket 210 also includes an end bracket 400 that is fixed to the pack case 602.

[0069] The end brackets 400 provided on the end plates 300 and the side plates 200 have fastening surfaces 410 parallel to the width direction W, and one or more fastening holes 412 are formed on the fastening surfaces 410 of the end brackets 400. The fastening surfaces 410 of the end brackets 400 are seated on mounting parts 640 provided on the pack case 602 (see FIG. 9 ), and the battery block 10 is fixed to the pack case 602 by joining or fastening the end brackets 400 to the mounting parts 640 of the pack case 602 via the fastening holes 412.

[0070] The end bracket 400 may have a reinforcing rib 420 in the form of a right-angled triangle perpendicular to the fastening surface 410 to reinforce the rigidity against a load in the height direction H. For reference, one or more concave surfaces 320 similar to the concave surface 222 of the side plate 200 may be bent to reinforce the rigidity of the end plate 300 itself, and an upper flange 330 may be provided on the upper end of the end plate 300 to stably fix the cell array 100.

[0071] Second embodiment 6 and 7 are diagrams showing a structure in which the battery block 10 of FIG.

[0072] The battery block 10 of the present invention can expand the number of cell arrays 100 to a desired number along the width direction W via the side plates 200 and the side brackets 210. In the second embodiment of the present invention, one embodiment of such expansion of the battery block 10 will be described.

[0073] 6, the side bracket 210 has fastening grooves 212 on both the left and right sides of the center of the side plate 200 in the width direction W. This makes it possible to connect one end plate 300 to each side of the side plate 200 in the width direction W.

[0074] As shown in FIG. 7, another cell array 100 arranged along the width direction W shares one central side plate 200, and the welding bolts 310 provided on a pair of end plates 300 arranged on the front and rear surfaces of the other cell array 100 are fixed to the fastening grooves 212 of the side brackets 210, thereby allowing the multiple cell arrays 100 to be expanded along the width direction W.

[0075] In this manner, since the side bracket 210 has the fastening grooves 212 on both the left and right sides, one end plate 300 can be coupled to each side of one side plate 200, and adjacent cell arrays 100 share one side plate 200, so that in a structure in which a plurality of battery blocks 10 are connected, the total number of side plates 200 required is one more than the number of cell arrays 100. Therefore, the space efficiency of the battery pack 600 equipped with the battery block 10 of the present invention is further improved.

[0076] The venting devices 114 provided on the upper surfaces of the prismatic cells 110 arranged in the cell array 100 are also aligned in a row, and a venting duct 120 is provided covering the upper part of the entire venting device 114, thereby enabling the discharge of high-temperature gas, flames, and various overheated particles ejected from inside the overheated prismatic cells 110 to a safe direction.

[0077] Third embodiment In the third embodiment of the present invention, a structure will be described in which the above-mentioned battery block 10 expanded in the width direction W is mounted in a pack case 602. FIGS. 8 and 9 are drawings showing a structure in which the battery block 10 is fixed to the pack case 602.

[0078] A pack case 602 in which a plurality of battery blocks 10 are mounted includes a base plate 610 forming a bottom surface, side frames 620 forming walls along the four sides of the base plate 610, and an upper cover 630 sealing the upper surface of the pack case 602. The illustrated pack case 602 shows an example in which two battery modules 500, each having a side plate 200 and an end plate 300 coupled in a lattice shape such that three cell arrays 100 are arranged in a row, are arranged in two rows (in this specification, an assembly in which a plurality of battery blocks are connected together via a side plate according to the second embodiment is referred to as a battery module). For reference, one battery module 500 is omitted from FIG. 8 in order to clearly show the structure of the pack case 602.

[0079] In one battery module 500 having three cell arrays 100 arranged in a row, end brackets 400 are exposed along the front and rear end plates 300, and one end bracket 400 is also exposed on the side bracket 210 between the end plates 300.

[0080] 9, a pack case 602 is provided with rail-shaped mounting parts 640 corresponding to fastening surfaces 410 of end brackets 400 protruding from the front and rear surfaces of a battery module 500. The mounting part 640 includes a pair of side mounting parts 642 coupled to or integrally formed with the side frames 620, and a center mounting part 644 provided across the center of the base plate 610, which are arranged in parallel.

[0081] When the battery module 500 is inserted into the space between the side mounting portion 642 and the center mounting portion 644, the fastening surface 410 of the end bracket 400 faces the mounting portion 640 of the pack case 602, and all of the battery blocks 10 are fixed together to the pack case 602 by joining or fastening the end bracket 400 to the mounting portion 640 of the pack case 602 through the fastening holes 412.

[0082] Here, the end brackets 400 provided on the battery block 10, the corresponding mounting parts 640 provided on the pack case 602, and the pack case 602 having the base plate 610 and the side frame 620 as a basic skeleton are all made of a thermally conductive material (e.g., aluminum, SUS, etc.). As described in the first embodiment, the side plate 200, the end plate 300, and the side bracket 210 connecting them are all made of a thermally conductive material and are thermally connected to each other. Furthermore, the end plate 300 and the end brackets 400 provided on the side plate 200 are also made of a thermally conductive material, and the entire structure of the pack case 602 including the mounting parts 640 are made of a thermally conductive material, so that the rectangular cells 110, the cell array 100, the battery block 10, the battery module 500, and the pack case 602 are all thermally connected to each other.

[0083] 10 is a diagram showing a structure in which the battery block 10 and the pack case 602 are thermally connected, and any one of the prismatic cells 110, represented by shading, transfers heat in all directions by forming one thermal capacity with all surrounding structures thermally connected (arrows indicate approximate heat transfer paths). Since any prismatic cell 110 can transfer heat in all directions, eventually reaching the pack case 602, a passive cooling structure is completed that effectively suppresses temperature rise during charging and discharging and quickly disperses heat in emergency situations such as thermal runaway and heat propagation.

[0084] Meanwhile, when the end brackets 400 of each battery block 10 are coupled and fixed to the mounting portions 640 of the pack case 602, a downward fixing force pressing the cell array 100 against the base plate 610 is naturally generated in the side plates 200 and, further, in the upper flanges 330, 230 bent and formed at the upper ends of the end plates 300, thereby firmly adhering the cell array 100 to the base plate 610.

[0085] The close contact between the cell array 100 and the base plate 610 plays an important role in smoothly transferring heat generated in the cell array 100 to the base plate 610. Therefore, it can be said that it is advantageous for the upper flanges 230, 330 to generate a sufficient downward fixing force to control the tolerance in a direction in which a minute gap occurs between the fastening surface 410 of the end bracket 400 and the mounting portion 640 when the battery block 10 or the battery module 500 is inserted into the pack case 602.

[0086] 8, a view showing a structure in which the upper flange 230 of the side plate 200 fixes the cell array 100. As described above, the upper flange 230 of the side plate 200 contacts the upper surface of the adjacent cell array 100 sharing the side plate 200, and generates a downward fixing force that tightly attaches the cell array 100 to the base plate 610 when the battery block 10 is mounted to the pack case 602 via the end bracket 400. However, since there are no corresponding cell arrays 100 for the upper flanges 230 at both ends in the width direction of the pack case 602, it is preferable to form flange mounting parts 650 in the side frame 620 and support the vacant upper flanges 230 in the flange mounting parts 650 to achieve stable mounting while allowing a uniform pressure force to act on the edge of the cell array 100.

[0087] 11 is a diagram showing a heat transfer structure between a battery block 10 and a base plate 610. The battery pack 600 of the present invention has excellent adhesion of the battery block 10 to the base plate 610 due to the configuration of the end bracket 400 and the upper flange 230. Therefore, the battery pack 600 of the present invention does not need to use an adhesive to fix the lower part of the battery block 10, and since no adhesive is used, the lower part of the battery block 10 is cooled smoothly, i.e., heat transfer is facilitated. In addition, since no adhesive is used, not only is the installation process of the battery block 10 simplified, but damage to the battery block 10 when it is removed is prevented.

[0088] In the illustrated embodiment, the base plate 610 includes a heat sink 612 having cooling channels 614 through which a cooling medium flows. The heat sink 612 includes a lower plate having the cooling channels 614 formed therein and an upper plate joined to the lower plate to form a fluid-tight seal, and the upper plate is provided with a pair of inlet / outlet adapters 616 that form an inlet / outlet for the cooling medium flowing through the cooling channels 614 (only one inlet / outlet adapter is shown in FIG. 11 due to the orientation of the drawing).

[0089] A thermally conductive thermal interface material 618 (TIM) may be interposed between the contact surface between the heat sink 612 of the base plate 610 and the battery block 10. The thermally conductive thermal interface material 618 refers to a known material having a significantly higher thermal conductivity than metal materials such as aluminum, and the thermally conductive thermal interface material 618 contributes to quickly transferring heat generated in the battery block 10 to the heat sink 612 by having a high thermal conductivity and acting as a filler for filling minute irregularities on the contact surface. The function of the thermally conductive thermal interface material 618 is reliably guaranteed by the close contact between the base plate 610 and the battery block 10 by the end bracket 400 and the upper flange 230.

[0090] The present invention has been described in more detail above with reference to the drawings and embodiments, etc. However, the configurations described in the drawings or embodiments, etc. in this specification are merely one embodiment of the present invention and do not fully represent the technical ideas of the present invention, and therefore there may be various equivalents and modifications that can replace them at the time of filing this application. [Explanation of symbols]

[0091] 10: Battery block 100: Cell array 110: Square cell 112: Electrode terminal 114: Venting equipment 120: Venting duct 200: Side plate 210: Side bracket 212: Fastening groove 220: Joint rib 222: Concave 230: Upper flange 240: Endothermic / venting pouch 242: Absorbent material 244: Heat-sealing sealing section 246: Weak part 300: End plate 310: Welding bolts 320: Concave 330: Upper flange 400: End bracket 410: Fastening surface 412: Concluding hole 420: Reinforcement rib 500: Battery module 600: Battery pack 602: Pack case 610: Base plate 612: Heat sink 614: Cooling channel 616: Inflow / Outflow Adapter 618: Thermally conductive thermal interface materials 620: Side frame 630: Top cover 640: Mounting part 642: Side mounting part 644: Center mounting part 650: Flange mounting part W: Width direction L: Longitudinal H: Height

Claims

1. a battery block including a cell array including a plurality of rectangular cells aligned in a row, a pair of side plates disposed on both sides of the cell array, respectively, and a pair of end plates disposed on front and rear sides of the cell array, respectively, wherein both ends in a width direction of the end plates are fixed to side brackets provided on both ends in a length direction of the side plates, and the cell array is bound into one block; a pack case in which a plurality of the battery blocks are mounted; The side plate, the end plate, and the side bracket are all made of a thermally conductive material, thereby being thermally connected to each other.

2. The battery pack according to claim 1 , wherein the end plate includes an end bracket fixed to a mounting portion provided on the pack case.

3. The side bracket is The battery pack according to claim 1 , further comprising an end bracket fixed to a mounting portion provided on the pack case.

4. 3. The battery pack according to claim 2, wherein the end bracket, the mounting portion, and the pack case are all made of a thermally conductive material, and are thereby thermally coupled to each other.

5. The end bracket is The battery pack of claim 2 , further comprising a fastening surface parallel to a width direction, the fastening surface having one or more fastening holes formed therein, the end bracket being fixed to the mounting portion through the fastening holes.

6. The end bracket is The battery pack of claim 5 , further comprising a reinforcing rib perpendicular to the fastening surface.

7. The side plate is 5. The battery pack of claim 4, wherein the battery pack is a single plate bent into an open-top "U" shape to form an internal space.

8. The side plate is The folded plate has concave surfaces on both sides; The battery pack according to claim 7 , wherein the concave surfaces face each other and are joined together along the longitudinal direction of the concave surfaces to form at least one joining rib.

9. The side plate includes at least one heat absorption / venting pouch inserted into an internal space defined by the joining rib, 9. The battery pack of claim 8, wherein the heat absorption / venting pouch hermetically houses a liquid-impregnated absorbent material.

10. The absorbent material is 10. The battery pack of claim 9, wherein the superabsorbent matrix comprises a superabsorbent polymer or a superabsorbent fiber.

11. the heat absorption / venting pouch has heat seals along its edges; The battery pack according to claim 10 , wherein the heat-sealed sealing portion is provided with a weakened portion having a relatively low burst strength.

12. an upper flange is provided at an upper end of the side plate so as to be bent to contact an upper surface of the cell array; The battery pack according to claim 7 , wherein the end bracket is fixed to the mounting portion, so that the upper flange applies a downward fixing force that presses the cell array against a base plate of the pack case.

13. The pack case includes: the pack case includes a base plate forming a bottom surface, side frames forming walls along four sides of the base plate, and an upper cover sealing an upper surface of the pack case, The battery pack according to claim 12 , wherein an interior of the base plate is provided with a cooling passage through which a cooling medium flows.

14. The battery pack according to claim 13 , wherein a thermally conductive thermal interface material is interposed between contact surfaces of the base plate and the battery block.

15. The side bracket has a fastening groove into which a welding bolt protruding from the end plate is inserted, The battery pack according to claim 7 , wherein the weld bolt and the fastening groove are joined to each other by welding.

16. The side bracket is The battery pack according to claim 15 , wherein the fastening grooves are provided on both left and right sides of a width direction center of the side plate.

17. Another cell array arranged along the width direction shares the side plate, 17. The battery pack of claim 16, wherein welding bolts provided on a pair of end plates respectively disposed on front and rear surfaces of the other cell array are fixed to fastening grooves of the side brackets, thereby expanding the plurality of cell arrays along a width direction.

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