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 provided with a heat-dissipating passive cooling structure, wherein all prismatic cells included in a battery block mounted on the battery pack are thermally connected not only to other adjacent battery blocks but also to the entire pack case, and heat generated in the prismatic cells can be quickly dissipated by maximizing the heat capacity around the prismatic cells.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0168740 filed on December 6, 2022, and all contents disclosed in the document of said Korean patent application are incorporated as a part of the present specification. Background Art

[0003] Unlike primary batteries, secondary batteries are rechargeable, and have been extensively researched and developed in recent years due to the possibility of miniaturization and large capacity. With the increase in technological development and demand for mobile devices, and the emergence of electric vehicles and energy storage systems in response to the era's demand for environmental protection, the demand for secondary batteries as an energy source is increasing more rapidly.

[0004] Secondary batteries are classified into coin-type batteries, cylindrical batteries, prismatic batteries, and pouch-type batteries according to the shape of the battery case. In a secondary battery, an electrode assembly mounted inside a battery case is a chargeable and dischargeable power generating element formed of a laminated structure of electrodes and a separation membrane.

[0005] In the form of a battery pack, a plurality of battery cells of secondary batteries can form one assembly. The battery pack can increase energy density and can be mounted in devices requiring high energy, such as electric vehicles. A battery pack outputs a defined power by electrically connecting a large number of battery cells, cools battery cells whose temperature rises during operation, and is equipped with various safety devices that respond to emergency situations such as ignition.

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

[0007] Furthermore, when secondary batteries are arranged in a group such as modules or packs, a thermal runaway in one secondary battery can cause thermal propagation, leading to continuous overheating of surrounding secondary batteries. In addition, the flammable gases released from the overheated secondary batteries and ignition sources such as heating electrodes pose a high risk of fire, so it is necessary to suppress such ignition risks.

[0008] In this regard, in order to increase the energy density per unit volume, a structure is required that can more efficiently dissipate the heat generated in the battery cells during the charging and discharging process by integrating more battery cells into the same pack space. [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] The present invention aims to provide a battery pack in which each individual cell constituting the battery pack is thermally connected to the battery block, battery module, and even the pack case, thereby ensuring sufficient heat capacity, and thus enabling rapid dissipation of heat generated in the prismatic cells and effectively suppressing temperature rise.

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

[0011] The present invention relates to a battery pack, and in one example includes a cell array comprising a plurality of rectangular cells arranged in a row, a pair of side plates positioned on both sides of the cell array, and a pair of end plates positioned on the front and rear sides of the cell array, the widthwise ends of the end plates being fixed to side brackets provided on the longitudinal ends of the side plates, and the cell array being constrained into a single block, and a pack case on which a plurality of the battery blocks are mounted, wherein the side plates, end plates, and side brackets are all made of a thermally conductive material and are therefore 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] Furthermore, 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 part, and the pack case are all made of a thermally conductive material, thus being thermally connected to each other.

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

[0016] Furthermore, the end bracket may be provided with reinforcing ribs perpendicular to the fastening surface.

[0017] Furthermore, the above-mentioned side plate may consist of a single plate bent into a "∪" shape with its upper end open to form an internal space.

[0018] Furthermore, the side plate may have concave surfaces on both sides of the bent plate, and these concave surfaces may face each other and be 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-absorbing / venting pouch inserted into the internal space partitioned by the joining ribs, and the heat-absorbing / venting pouch seals and houses an absorbent material impregnated with liquid.

[0020] In one embodiment, the absorbent material may be a highly absorbent matrix containing a superabsorbent polymer (SAP) or a superabsorbent fiber (SAF).

[0021] Furthermore, the heat-absorbing / venting pouch may have a heat-sealed portion along its edge, and the heat-sealed portion may have a weaker portion with relatively lower burst strength.

[0022] On the other hand, the upper end of the side plate is provided with an upper flange that is bent to contact the upper surface of the cell array, and the end bracket is fixed to the mounting portion, thereby the upper flange provides 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 that forms the bottom surface, side frames that form walls along all four sides of the base plate, and an upper cover that seals the top surface of the pack case, and the inside of the base plate may be provided with a cooling channel through which a cooling medium flows.

[0024] Furthermore, a thermally conductive thermal interface material (TIM) may be interposed between the contact surface between the base plate and the battery block.

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

[0026] Preferably, the side bracket may be provided with the fastening grooves on both left and right sides respectively with reference to the center in the width direction of the side plate.

[0027] Thereby, another cell array arranged along the width direction shares the side plate, and a plurality of cell arrays can be expanded along the width direction by fixing the weld bolts provided on a pair of end plates respectively arranged on the front and rear surfaces of said another cell array to the fastening grooves of the side bracket. [Advantageous Effects of Invention]

[0028] In the battery pack of the present invention having the above configuration, the plate that restrains a plurality of prismatic cells to form one battery block, the bracket that mounts the battery block to the pack case, and the structure of the pack case are all made of a thermally conductive material and are thermally connected to each other.

[0029] Thereby, in the battery pack of the present invention, not only the battery block that restrains the prismatic cells themselves, but also other surrounding battery blocks and even the pack case form a single heat capacity. By securing such a large heat capacity, temperature rise during charge and discharge is effectively suppressed, and a passive cooling structure that rapidly dissipates heat even in emergency situations such as thermal runaway and thermal propagation is realized.

[0030] However, the technical effects obtainable by the present invention are not limited to the above-described effects, and other effects not mentioned can be clearly understood by a person skilled in the art from the description of the invention set forth below.

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

[0032] [Figure 1] This is a drawing showing a battery block according to one embodiment of the present invention. [Figure 2] Figure 1 is an exploded perspective view of the battery block. [Figure 3] This is a drawing showing the side plate. [Figure 4] This is a cross-sectional view taken along the line "AA" in Figure 3. [Figure 5] Figure 3 shows a cross-sectional view taken along the "BB" line. [Figure 6] This is a diagram showing a structure in which the battery block is expanded in the width direction. [Figure 7] This is a diagram showing a structure in which the battery block is expanded in the width direction. [Figure 8] This drawing illustrates a structure in which the battery block of the present invention is fixed to a pack case. [Figure 9] This drawing illustrates a structure in which the battery block of the present invention is fixed to a pack case. [Figure 10] This is a plan view of a battery block showing a structure in which the battery block and the pack case are thermally connected. [Figure 11] This is a diagram showing the heat transfer structure between the battery block and the base plate. [Modes for carrying out the invention]

[0033] The present invention can be modified in various ways and may have a variety of embodiments; therefore, specific embodiments are described in detail below.

[0034] However, this is not intended to limit the present invention to any particular embodiment, but rather should be understood to include all modifications, equivalents, or substitutions that fall within the spirit and technical scope of the present invention.

[0035] In the present invention, terms such as "includes" and "have" are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof as described in the specification, and do not preemptively exclude the presence or possibility of adding one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0036] Furthermore, in this invention, when a part such as a layer, film, region, or plate is described as being "on top" of another part, this includes not only the case where it is "directly on top" of the other part, but also the case where another part is located in between. Conversely, when a part such as a layer, film, region, or plate is described as being "below" another part, this includes not only the case where it is "directly below" the other part, but also the case where another part is located in between. Also, in this application, being "on top" may include being located not only at the top but also 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 they are mounted.

[0038] The battery block includes a cell array containing a plurality of rectangular cells arranged in a row, a pair of side plates positioned on each side of the cell array, and a pair of end plates positioned on the front and rear sides of the cell array, wherein the widthwise ends of the end plates are fixed to side brackets provided on the longitudinal ends of the side plates, and the cell array is constrained to a single block.

[0039] Here, the side plate, the end plate, and the side bracket are all made of a thermally conductive material and are therefore thermally connected to each other. The end bracket provided on the end plate and / or side plate, the mounting portion of the pack case to which the end bracket is fixed, and the pack case are all made of a thermally conductive material and are therefore thermally connected to each other.

[0040] In this battery pack of the present invention, the prismatic cells and the cell arrays that comprise them are thermally connected not only to the battery block that constrains them, but also to other surrounding battery blocks and even to the pack case. As a result, all the structures surrounding any one prismatic cell constitute a single thermal mass. By securing such a large thermal mass, the temperature rise during charging and discharging is effectively suppressed, and a passive cooling structure is realized that rapidly dissipates heat even in emergency situations such as thermal runaway or heat propagation.

[0041] Specific embodiments of the present invention will be described in detail below with reference to the attached drawings. Herein, the directions of front, back, up, down, left, and right used to specify relative positions are for the purpose of aiding the understanding of the invention, and unless otherwise defined, the directions shown in the drawings are used as the reference.

[0042] (First Embodiment) Figure 1 is a drawing showing a battery block 10 according to one embodiment of the present invention, and Figure 2 is an exploded perspective view of the battery block 10 of Figure 1. Below, the configuration of the battery block 10 mounted on the battery pack 600 of the present invention will be described 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 attached Figures 1 and 2, the battery block 10 according to the present invention includes a pair of side plates 200, a pair of end plates 300 that are bound together to form a parallelepiped space, and a cell array 100 that is housed in the parallelepiped space.

[0044] A cell array 100 refers to a group of cells consisting of multiple rectangular cells 110 arranged in a row. Each individual rectangular cell 110 is a complete rectangular secondary battery that can be charged and discharged independently. In the illustrated embodiment, one example is shown where 12 rectangular cells 110 come together to form a single cell array 100. It is common for all rectangular cells 110 to be of the same specifications, and the rectangular cells 110 arranged in a row generally form a parallelepiped.

[0045] For reference, the rectangular cell 110 shown in the figure corresponds to a unidirectional rectangular cell 110 in which all positive and negative electrode terminals 112 are arranged 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 that corresponds to a safety valve that ruptures to release internal pressure when pressure acts inside the rectangular cell 110, and may include, for example, a rupture disc made of a thin plate-like member of metal material with a notch. When the internal pressure of the sealed rectangular cell 110 rises, tensile deformation occurs throughout the thin plate due to the pressure, and the notched portion, which is weaker, ruptures, releasing the internal pressure of the rectangular cell 110.

[0046] Furthermore, the electrode terminals 112 of the rectangular cells 110 on the cell array 100 may be arranged so that identical polarity terminals are arranged in a row consecutively, or so that opposite polarity terminals alternate, for the convenience of parallel or series electrical connection. In other words, the alignment of multiple rectangular cells 110 in a row does not necessarily mean that the polarity of the electrode terminals 112 are aligned in a row.

[0047] A pair of side plates 200 are positioned on both sides of the cell array 100, and a pair of end plates 300 are positioned on the front and rear sides of the cell array 100. The ends of the end plates 300 in the width direction W are fixed to side brackets 210 provided on both ends of the side plates 200 in the longitudinal direction L, and the cell array 100 is constrained into a single block by the interconnection of the end plates 300 and the side plates 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, such as aluminum or stainless steel (SUS), which is a metal material with excellent thermal conductivity, and as a result the side plate 200 and the end plate 300 are thermally connected. In other words, for a given rectangular cell 110 on the cell array 100, the side plate 200 and the end plate 300 that are in contact with the cell array 100, as well as the surrounding rectangular cells 110, form a single thermal mass that is thermally connected to each other.

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

[0050] Figure 3 is a drawing of the side plate 200, and Figure 4 is a cross-sectional view taken along the line "AA" in Figure 3. The side plate 200 shown in the drawing consists of a single plate bent into an "∪" shape with the upper end open to form an internal space. By bending the single plate into an "∪" shape with the upper end open, the side plate 200 exhibits excellent mechanical strength while remaining lightweight.

[0051] Furthermore, as shown in Figures 3 and 4, the side plate 200 has concave surfaces 222 on both sides of the bent plate, and the opposing concave surfaces 222 are joined together 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 in the center of the side plate 200.

[0052] A single plate bent into a "U" shape exhibits excellent durability and strength against compression and tension in the longitudinal direction L due to its bent structure, but may be relatively weak against forces in the height direction H. The connecting rib 220 improves rigidity against forces in the height direction H by combining the structure of the concave surface 222 and the concave surfaces 222 on both sides of the side plate 200 into one by welding or binding with rivets or the like.

[0053] The structure of the side plate 200, namely the structure of a single plate bent into a "∪" shape and the interconnected concave surface 222, allows the side plate 200 to be lightweight while possessing strong mechanical rigidity. As a result, in the battery block 10 of the present invention, the side plate 200 replaces the crossbeam configuration provided in conventional battery packs, thereby simplifying the structure of the battery pack 600. This improves the space utilization rate of the battery pack 600, further increasing the energy density for the same volume and potentially reducing costs.

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

[0055] The heat-absorbing / venting pouch 240 seals and houses an absorbent material 242 impregnated with a large amount of liquid. The liquid impregnated in the absorbent material 242 absorbs heat from the rectangular cell 110 transmitted through the side plate 200. In other words, the heat-absorbing / venting pouch 240 has a heat capacity corresponding to the heat absorbed by the liquid impregnated in the absorbent material 242, as well as the latent heat absorbed when the liquid vaporizes above its boiling point. The heat absorbed and latent heat of the liquid add a considerable heat capacity to the side plate 200, allowing it to absorb more heat from the rectangular cell 110, thereby further slowing the temperature rise of the rectangular cell 110.

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

[0057] The liquid impregnated in large quantities in the absorbent material 242 housed in the heat-absorbing / venting pouch 240 absorbs the heat generated in the rectangular cell 110. When its temperature exceeds its boiling point and vaporizes, the rapid volume increase due to the phase change from liquid to gas creates internal pressure in the heat-absorbing / venting pouch 240 that seals the absorbent material 242. When the internal pressure exceeds the bursting strength of the heat-absorbing / venting pouch 240, a portion of the pouch 240 ruptures, releasing vapor. This release of vapor (venting) cools the high-temperature rectangular cell 110 once again.

[0058] Here, the heat-absorbing / venting pouch 240 may be configured such that the location from which the vapor is discharged is favorably guided so that the discharged vapor provides an effective cooling effect. For this purpose, a weak area 246 may be provided in a portion of the heat-sealed portion 244 formed along the edge of the heat-absorbing / venting pouch 240. The weak area 246 is configured to preferentially rupture due to the increase in internal pressure caused by the vaporization of the liquid, by locally reducing the sealing strength of the heat-sealed portion 244. That is, the weak area 246 may be formed in a way that makes the heat-sealed strength of the heat-sealed portion 244 lower than the surrounding area. For example, the thickness of the weak area 246 can be made relatively thinner than the surrounding area, a notch can be formed to reduce the strength, or it can be formed by locally removing the aluminum thin film layer that maintains the durability of the laminate sheet.

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

[0060] In the present invention, the specific types of superabsorbent resins and superabsorbent fibers produced therefrom are not particularly limited and can be used without restriction as long as they have excellent absorption capacity for fluids, especially water. Examples of superabsorbent resins in the present invention include polyacrylic acid, polyacrylates, polyacrylate graft polymers, starch, crosslinked carboxymethylated 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, polyvinylphosphonic acid, polyvinyl phosphoric acid, polyvinyl sulfuric acid, and sulfuric acid. One or more selected from the group consisting of polystyrene polyacrylate, polyvinylamine, polydialkylaminoalkyl(meth)acrylamide, polyethyleneimine, polyallylamine, polyarylguanidine, polydimethyldiallylammonium hydroxide, quaternized polystyrene derivatives, guanidine-modified polystyrene, quaternized poly(meth)acrylamide, polyvinylguanidine, and mixtures thereof are examples, preferably one or more selected from the group consisting of crosslinked polyacrylates, crosslinked polyacrylic acids, and crosslinked acrylic acid copolymers, but 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 is preferably a copolymer comprising an acrylic acid monomer and one or more copolymers 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 superabsorbent resin may have an absorption capacity of 10 g / g to 500 g / g of water, preferably 50 g / g to 200 g / g, but is not limited thereto. That is, 1 g of superabsorbent resin can absorb 10 g to 500 g of water, preferably 50 g to 200 g.

[0063] In this invention, the duration of the cooling effect can be improved by increasing the amount of water absorbed by the superabsorbent resin. However, if the amount exceeds 500 g / g, the fluidity of the superabsorbent resin increases, making it difficult to maintain its shape, and thus it cannot exhibit effective cooling. Conversely, if the amount is less than 10 g / g, the duration of the cooling effect may be too short, making it inefficient.

[0064] Furthermore, in the first embodiment of the present invention, the liquid impregnated in the absorbent material 242 may be water. Water is the substance with the highest specific heat and latent heat among readily available liquids. Therefore, the water contained in the absorbent material 242 absorbs a large amount of heat during the phase change process from before vaporization to gas, making it suitable for application to the endothermic / venting pouch 240 of the present invention.

[0065] On the other hand, an upper flange 230 is formed by bending at the upper end of the side plate 200, which contacts the upper surface of the cell array 100. The upper flange 230 generates a downward fixing force that pushes 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 Figures 8 and 9 below.

[0066] Referring to Figures 1 and 2, the side brackets 210 provided at both ends of the side plate 200 are equipped with fastening grooves 212 into which welding bolts 310, which are provided protruding from the end plate 300, are inserted, and the welding bolts 310 and the fastening grooves 212 are joined together by welding.

[0067] Welding bolts 310 provided on a pair of end plates 300, respectively, positioned on the front and rear surfaces of the cell array 100, provide fastening points to the side brackets 210, and the assembly positions of the side plates 200 and end plates 300 are temporarily aligned by fitting fastening grooves 212 into the welding bolts 310. For stable and robust connection of the side plates 200 and end plates 300, and for strong constraint on the cell array 100, the welding bolts 310 and fastening grooves 212 may be provided in a pair, upper and lower, with reference to the center of the cell array 100 in the height direction H.

[0068] Looking at Figures 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 bracket 400 provided on the end plate 300 and the side plate 200 has a fastening surface 410 parallel to the width direction W, and one or more fastening holes 412 are formed on the fastening surface 410 of the end bracket 400. The fastening surface 410 of the end bracket 400 is fixed to the mounting portion 640 provided on the pack case 602 (see Figure 9), and the battery block 10 is fixed to the pack case 602 by joining or fastening the end bracket 400 to the mounting portion 640 of the pack case 602 via the fastening holes 412.

[0070] Furthermore, the end bracket 400 can be reinforced against loads in the height direction H by providing reinforcing ribs 420 in the shape of a right triangle perpendicular to the fastening surface 410. For reference, in order to reinforce the rigidity of the end plate 300 itself, one or more concave surfaces 320 similar to the concave surface 222 of the side plate 200 may be formed by bending, and an upper flange 330 may also be provided at the upper end of the end plate 300 for stable fixing of the cell array 100.

[0071] (Second Embodiment) Figures 6 and 7 are diagrams showing a structure in which the battery block 10 in Figure 1 is extended in the width direction W.

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

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

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

[0075] Thus, by providing fastening grooves 212 on both the left and right sides of the side bracket 210, one end plate 300 can be attached to each side of a single side plate 200. In a structure where multiple battery blocks 10 are connected by adjacent cell arrays 100 sharing one side plate 200, the total number of side plates 200 required is only one more than the number of cell arrays 100. Therefore, the spatial efficiency of the battery pack 600 equipped with the battery block 10 of the present invention is further improved.

[0076] Furthermore, the venting devices 114 provided on the upper surface of the rectangular cells 110 aligned in the cell array 100 are also aligned in a single line. However, by providing a venting duct 120 that covers the top of the entire venting device 114, the discharge of high-temperature gas, flames, and various overheated particles ejected from inside the overheated rectangular cells 110 can be safely guided in a safe direction.

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

[0078] The pack case 602, in which multiple battery blocks 10 are mounted, includes a base plate 610 forming the bottom surface, side frames 620 forming walls along all four sides of the base plate 610, and an upper cover 630 that seals the top surface of the pack case 602. The illustrated pack case 602 shows an example in which two battery modules 500 are arranged in two rows, with side plates 200 and end plates 300 connected in a grid pattern so that three cell arrays 100 form a row (in this specification, an assembly in which multiple battery blocks are integrally connected via side plates according to the second embodiment is referred to as a battery module). For reference, in order to clearly show the structure of the pack case 602, one battery module 500 is omitted from the illustration in Figure 8.

[0079] A single battery module 500, consisting of three cell arrays 100 arranged in a row, has end brackets 400 exposed along the front and rear end plates 300, and one end bracket 400 also exposed on the side bracket 210 between the end plates 300.

[0080] Referring to the cross-sectional view in Figure 9, the pack case 602 is provided with rail-shaped mounting portions 640 corresponding to the fastening surfaces 410 of the end brackets 400 that protrude from the front and rear surfaces of the battery module 500. The mounting portions 640 consist of a pair of side mounting portions 642 that are coupled to or integrally formed with the side frame 620, and a center mounting portion 644 that is provided across the center of the base plate 610, 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. By joining or fastening the end bracket 400 to the mounting portion 640 of the pack case 602 via the fastening holes 412, all the battery blocks 10 are fixed to the pack case 602 together.

[0082] Here, the end bracket 400 provided on the battery block 10, the corresponding mounting portion 640 provided on the pack case 602, and the pack case 602, which has a base plate 610 and a side frame 620 as its basic framework, are all made of a thermally conductive material (for example, aluminum or stainless steel). 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 bracket 400 provided on the end plate 300 and the side plate 200 are also made of a thermally conductive material, and the entire structure of the pack case 602, including the mounting portion 640, is made of a thermally conductive material, so that the prismatic cell 110, cell array 100, battery block 10, battery module 500, and pack case 602 are all thermally connected.

[0083] Figure 10 is a diagram showing a thermally connected structure between the battery block 10 and the pack case 602. Any one of the prismatic cells 110, represented by shading (hatching), will transfer heat in all directions by forming a single heat capacity with all surrounding structures (arrows indicate approximate heat transfer paths). Since any prismatic cell 110 can ultimately transfer heat in all directions to the pack case 602, a passive cooling structure is created that effectively suppresses temperature rise during charging and discharging and rapidly dissipates heat even in emergency situations such as thermal runaway or heat propagation.

[0084] On the other hand, when the end brackets 400 of each battery block 10 are joined and fixed to the mounting portion 640 of the pack case 602, the side plates 200 and the upper flanges 330 and 230 formed by bending at the upper ends of the end plates 300 naturally generate a downward fixing force that pushes the cell array 100 against the base plate 610, thereby firmly adhering the cell array 100 to the base plate 610.

[0085] The tight contact between the cell array 100 and the base plate 610 plays a crucial role in smoothly transferring the heat generated in the cell array 100 to the base plate 610. Therefore, when the battery block 10 or battery module 500 is placed inside the pack case 602, managing the tolerances in a way that creates a small gap between the fastening surface 410 and the mounting portion 640 of the end bracket 400 is advantageous for the upper flanges 230 and 330 to generate sufficient downward fixing force.

[0086] Referring to Figure 8, this diagram shows the 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 that shares the side plate 200, and generates a downward fixing force that causes the cell array 100 to be tightly fixed to the base plate 610 when the battery block 10 is mounted on the pack case 602 via the end bracket 400. However, since there are no corresponding cell arrays 100 at both ends of the pack case 602 in the width direction, it is preferable to form flange mounting portions 650 on the side frame 620 and ensure stable mounting by supporting the empty upper flanges 230 on the flange mounting portions 650, while also ensuring that a uniform pressing force is applied to the edges of the cell array 100.

[0087] Figure 11 is a diagram showing the heat transfer structure between the battery block 10 and the 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 require the use of adhesive for fixing the lower part of the battery block 10, and the absence of adhesive allows for smoother cooling of the lower part of the battery block 10, i.e., heat transfer. In addition, since no adhesive is used, the installation process of the battery block 10 is simplified, and 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 equipped with a cooling channel 614 through which a cooling medium flows. The heat sink 612 comprises a lower plate in which the cooling channel 614 is formed and an upper plate joined to the lower plate to provide fluid sealing. The upper plate is provided with a pair of inlet / outlet adapters 616 that form an inlet and outlet for the cooling medium flowing through the cooling channel 614 (only one inlet / outlet adapter is shown in the illustrated direction in Figure 11).

[0089] Furthermore, a thermally conductive thermal interface material 618 (TIM) may be interposed between the contact surface of 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 with significantly higher thermal conductivity than metal materials such as aluminum. By having high thermal conductivity and acting as a filler to fill in the fine irregularities on the contact surface, the thermally conductive thermal interface material 618 contributes to the rapid transfer of heat generated in the battery block 10 to the heat sink 612. This function of the thermally conductive thermal interface material 618 is reliably ensured by the tight 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. However, the configurations described in the drawings or embodiments described herein are merely one embodiment of the present invention and do not represent the entire technical concept of the present invention. Therefore, at the time of filing, there may be various equivalents and modifications that can substitute for them. [Explanation of Symbols]

[0091] 10: Battery Block 100: Cell Array 110: Rectangular cell 112: Electrode terminal 114: Venting device 120: Vent duct 200: Side Plate 210: Side bracket 212: Fastening groove 220: Joining rib 222: Concave 230: Upper flange 240: Heat-absorbing / venting pouch 242: Absorbent material 244: Heat fusion sealing section 246: Vulnerable parts 300: End plate 310: Welding bolts 320: Concave 330: Upper flange 400: End bracket 410: Fastening surface 412: Fastening Hall 420: Reinforcement Rib 500: Battery Module 600: Battery Pack 602: Pack Case 610: Base plate 612: Heatsink 614: Cooling channel 616: Inlet / Outlet Adapter 618: Thermally conductive thermal interface material 620: Side frame 630: Top cover 640: Mounting part 642: Side mounting section 644: Center mounting part 650: Flange mounting section W: width direction L: Long direction H: Height direction

Claims

1. A battery block comprising a cell array including a plurality of rectangular cells aligned in a row, a pair of side plates positioned on each side of the cell array, and a pair of end plates positioned on the front and rear surfaces of the cell array, wherein both ends of the end plates in the width direction are fixed to side brackets provided on both ends of the side plates in the longitudinal direction, and the cell array is constrained to a single block, A pack case on which multiple battery blocks are mounted, A battery pack comprising, The aforementioned side plate is a single plate bent into a "∪" shape with its upper end open to form a space inside. The side plate has concave surfaces on both sides of the bent single plate, and the concave surfaces have at least one connecting rib facing each other and joined together along the longitudinal direction of the concave surface. A battery pack in which the side plate, end plate, and side bracket are all made of a thermally conductive material and are therefore thermally connected to one another.

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

3. The aforementioned 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. 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 therefore thermally connected to each other.

5. The aforementioned end bracket is The battery pack according to claim 2, comprising a fastening surface parallel to the width direction, one or more fastening holes formed in the fastening surface, and the end bracket being fixed to the mounting portion via the fastening holes.

6. The aforementioned end bracket is The battery pack according to claim 5, further comprising reinforcing ribs perpendicular to the fastening surface.

7. The side plate includes at least one heat-absorbing / venting pouch inserted into the internal space partitioned by the joining rib, The battery pack according to claim 1, wherein the heat-absorbing / venting pouch seals and houses an absorbent material impregnated with liquid.

8. The absorbent material is The battery pack according to claim 7, wherein the superabsorbent matrix comprises a superabsorbent polymer or superabsorbent fiber.

9. The heat-absorbing / venting pouch is provided with a heat-sealed portion along its edge, The battery pack according to claim 8, wherein the heat-sealed portion is provided with a weak portion that has relatively low burst strength.

10. An upper flange is provided at the upper end of the side plate, which is bent to contact the upper surface of the cell array. The battery pack according to claim 2, wherein the end bracket is fixed to the mounting portion, and the upper flange provides a downward fixing force that presses the cell array against the base plate of the pack case.

11. The aforementioned pack case is It includes a base plate that forms the bottom surface, side frames that form walls along all four sides of the base plate, and an upper cover that seals the top surface of the pack case. The battery pack according to claim 10, wherein a cooling channel through which a cooling medium flows is provided inside the base plate.

12. The battery pack according to claim 11, wherein a thermally conductive thermal interface material is interposed between the contact surface of the base plate and the battery block.

13. The side bracket is provided with a fastening groove into which a welding bolt protruding from the end plate is inserted, The battery pack according to claim 1, wherein the welding bolt and the fastening groove are joined together by welding.

14. The aforementioned side bracket is The battery pack according to claim 13, wherein the fastening grooves are provided on both the left and right sides with respect to the center in the width direction of the side plate.

15. Another cell array, arranged along the width direction, shares the side plate, The battery pack according to claim 14, wherein welding bolts provided on a pair of end plates, respectively, which are positioned on the front and rear surfaces of the other cell array, are fixed to fastening grooves of the side bracket, thereby extending the multiple cell arrays along the width direction.

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