Battery pack with integrated ventilation duct

Abstract

In one example, the battery pack includes a cell array in which a plurality of rectangular cells having venting devices on their upper surfaces are aligned in a row, a pair of side plates respectively disposed on both sides of the cell array, and a pair of end plates respectively disposed on a front and rear surface 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 into one block, and a pack case in which a plurality of the battery blocks are mounted, and an upper cover of the pack case is integrally formed with a venting duct that forms an integrated flow path for the plurality of venting devices arranged in a row on the upper surface of the cell array.

Description

[Technical field]

[0001] The present invention relates to a battery pack in which a venting duct is integrally formed on an upper cover of a pack case to guide high-temperature gas or flames ejected from a venting device provided on the upper surface of a row of prismatic cells in a predetermined exhaust direction.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0168749 dated December 6, 2022, and all contents disclosed in the documents of said 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 known as 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 any one secondary battery causes other surrounding secondary batteries to continuously overheat. Furthermore, there is a high risk of fire due to flammable gases released from an overheated secondary battery and ignition sources such as heated electrodes, so it is necessary to suppress such a risk of fire.

[0008] In order to prepare for emergency situations such as thermal runaway and heat propagation, secondary batteries are often equipped with a venting device as a safety valve. When the internal pressure of the secondary battery rises excessively, the venting device responds by opening itself to relieve the internal pressure, thereby preventing the secondary battery from collapsing structurally.

[0009] However, when the venting device is activated, combustible gas and an ignition source such as a heated electrode are ejected in random directions through the outlet for releasing the internal pressure, so it is necessary to appropriately control and guide the ejection direction. For this reason, a venting duct may be installed in the module to form a guide passage for the venting device. Summary of the Invention [Problem to be solved by the invention]

[0010] An object of the present invention is to provide a battery pack in which a guide passage for a venting device can be collectively formed for all secondary batteries included in a battery block or battery module constituting the battery pack through only a simple assembly process.

[0011] 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]

[0012] The present invention relates to a battery pack, and in one example, the battery pack includes: a cell array in which a plurality of rectangular cells having a venting device on an upper surface thereof are aligned in a row; a pair of side plates respectively disposed on both sides of the cell array; and a pair of end plates respectively disposed on a front and rear surface 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 into one block; and a pack case in which a plurality of the battery blocks are mounted, and an upper cover of the pack case is integrally formed with a venting duct that forms an integrated flow path for the plurality of venting devices arranged in a row on the upper surface of the cell array.

[0013] Here, it can be said that it is preferable that the venting duct is integrally formed with the upper cover by baking processing.

[0014] In one embodiment of the present invention, the venting duct includes a recess that is in close contact with an upper surface of a rectangular cell around the venting device, and a protrusion that forms a space surrounding the venting device.

[0015] A heat insulating sheet may be interposed between the recess of the venting duct and the upper surface of the rectangular cell.

[0016] The protrusion may have one side facing the side frame of the pack case forming a duct outlet, and the other side forming a closed surface.

[0017] An electrode terminal is disposed on either side of the venting device on the upper surface of the prismatic cell, and wiring ducts forming a space surrounding the electrode terminals on either side of the venting duct may be integrally formed by firing the upper cover.

[0018] Here, it can be said that it is preferable that the wiring duct is isolated from the duct outlet.

[0019] The duct outlet can be in communication with a venting outlet provided in a side frame of the pack case.

[0020] Meanwhile, in one embodiment of the present invention, the cell array includes a heat absorption / venting pouch disposed between the prismatic cells so as to contact the front and rear surfaces of the prismatic cells, the heat absorption / venting pouch hermetically housing an absorbent material impregnated with a liquid, the heat absorption / venting pouch has a heat fused sealing portion along its edge, and the heat fused sealing portion may have a fragile portion having a relatively low burst strength.

[0021] The weak portion of the heat absorbing / venting pouch may be located at an upper edge, and the heat insulating sheet may have a venting slit corresponding to the weak portion within a space formed by the convex portion of the venting duct.

[0022] In addition, the side plate of the battery block may be formed of a single plate bent into a U-shape with an open upper end to form an internal space, and a heat absorbing / venting pouch that hermetically houses an absorbent material impregnated with a liquid may be embedded in the internal space.

[0023] According to an embodiment, the side plate has concave surfaces on both sides of the folded plate, and at least one joining rib is provided along the longitudinal direction by joining the facing concave surfaces to each other, and the heat absorption / venting pouch can be inserted into an internal space partitioned by the joining rib. Effect of the Invention

[0024] According to the battery pack of the present invention having the above-mentioned configuration, after the battery blocks are mounted in the pack case, the pack case is simply sealed with the upper cover, and the ventilation ducts partitioned for each battery block are provided for all cell arrays. Therefore, since it is not necessary to provide a ventilation duct for each battery block, the assembly and disassembly process of the battery pack is simplified, and since the upper cover also serves as a ventilation duct, the amount of materials used is reduced, resulting in cost savings.

[0025] In addition, the upper cover formed by bending the vent duct integrally has improved mechanical rigidity due to its curved cross-sectional shape compared to conventional upper covers that have a simple flat shape, and therefore can more effectively protect the battery blocks inside the pack case.

[0026] 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.

[0027] 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]

[0028] [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] 2 is a diagram showing a structure in which the battery block of FIG. 1 is expanded in a width direction to form a battery module. [Figure 4] FIG. 2 is an exploded perspective view of the battery pack of the present invention. [Diagram 5] 1 is a diagram showing a battery pack of the present invention. [Figure 6] FIG. 6 is a cross-sectional view taken along line "AA" in FIG. 5. [Figure 7] FIG. 6 is a cross-sectional view taken along line "BB" in FIG. 5. [Figure 8] FIG. 6 is a cross-sectional view taken along line "CC" in FIG. 5. [Figure 9] 1 is a view showing another embodiment of a battery block according to the present invention; [Figure 10] FIG. 10 is a cross-sectional view taken along line "DD" in FIG. 9. [Figure 11] FIG. 10 is a cross-sectional view taken along line "EE" in FIG. 9. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] Since the present invention can be modified in various ways and can have various embodiments, specific embodiments will be described in detail below.

[0030] 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.

[0031] 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.

[0032] 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.

[0033] The present invention relates to a battery pack, and in one example, the battery pack includes a cell array in which a plurality of rectangular cells having a venting device on an upper surface are aligned in a row, a pair of side plates respectively disposed on both sides of the cell array, and a pair of end plates respectively disposed on a front and a rear surface 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 into one block, and a pack case in which a plurality of the battery blocks are mounted.

[0034] Here, the upper cover of the pack case is integrally formed with a venting duct that forms an integrated flow path for the multiple venting devices arranged in a row on the upper surface of the cell array, and preferably, the venting duct is integrally formed by sintering the upper cover.

[0035] According to the battery pack of the present invention as described above, the battery blocks are mounted in the pack case, and then the pack case is simply sealed with the upper cover, and ventilation ducts partitioned for each battery block are provided for all cell arrays.

[0036] Therefore, since there is no need to install a ventilation duct for each battery block, the assembly and disassembly process of the battery pack is simplified, and since the upper cover also serves as a ventilation duct, the amount of materials required is reduced, resulting in cost savings.

[0037] In addition, the upper cover formed by bending the vent duct integrally has improved mechanical rigidity due to its curved cross-sectional shape compared to conventional upper covers that have a simple flat shape, and therefore can more effectively protect the battery blocks inside the pack case.

[0038] 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.

[0039] (First embodiment) In the first embodiment of the present invention, a brief description will be given of a battery block 10 and a configuration in which a plurality of battery blocks 10 are connected to each other to form one battery module 500. The venting ducts 632 provided in the battery pack 600 of the present invention are arranged in parallel one for each battery block 10 that binds one cell array 100 in a block shape, and the battery block 10 described with reference to Figs. 1 to 3 has a structure suitable for installing a plurality of venting ducts 632 in a group.

[0040] Fig. 1 is a view showing a battery block 10 according to an embodiment of the present invention, and Fig. 2 is an exploded perspective view of the battery block 10 of Fig. 1. Referring to the accompanying Figs. 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 coupled thereto to form a parallelepiped-shaped space, and a cell array 100 accommodated in the parallelepiped space.

[0041] 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.

[0042] Here, the illustrated prismatic cell 110 corresponds to a unidirectional prismatic cell 110 in which positive and negative electrode terminals 112 are all arranged on the upper surface, and a venting device 114 is provided between the pair of electrode terminals 112. The venting devices 114 provided on the upper surfaces of the plurality of prismatic cells 110 arranged in the cell array 100 are also aligned in a line.

[0043] The venting device 114 is a device equivalent to a safety valve that bursts to release the internal pressure when pressure acts inside the prismatic cell 110, 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 breaks, releasing the internal pressure of the prismatic cell 110.

[0044] 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 at 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.

[0045] 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.

[0046] 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 end plate 300 in contact with the cell array 100 form a single thermal mass that is thermally connected to each other. In this way, the entire battery block 10 forms a single thermal mass, which not only mitigates a sudden temperature rise in 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.

[0047] 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 side plate 200 and the end plate 300 of the battery block 10 are attached to the mounting portion 640 of the pack case 602.

[0048] Referring again to Figures 1 and 2, side brackets 210 provided on both ends of side plate 200 have fastening grooves 212 into which weld bolts 310 protruding from end plate 300 are inserted, and the weld bolts 310 and the fastening grooves 212 are joined to each other by welding.

[0049] Welding bolts 310 provided on a pair of end plates 300 disposed 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.

[0050] 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.

[0051] 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 coupling the end brackets 400 to the mounting parts 640 of the pack case 602 through the fastening holes 412.

[0052] 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.

[0053] 3 is a diagram showing a structure in which the battery block 10 is expanded in the width direction W to form an integrated battery module 500. The battery block 10 of the present invention can expand the number of cell arrays 100 along the width direction W via the side plates 200 and the side brackets 210 to a desired number.

[0054] 3, 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.

[0055] 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, respectively, of the other cell array 100 are fixed to the fastening grooves 212 of the side brackets 210, thereby expanding the multiple cell arrays 100 along the width direction W.

[0056] 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.

[0057] Second embodiment FIG. 4 shows a structure in which the battery block 10 expanded in the width direction W described in the first embodiment is mounted in a pack case 602.

[0058] 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 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, each having a side plate 200 and an end plate 300 coupled in a lattice shape, are arranged in two rows so that three cell arrays 100 form a row (in this specification, an assembly in which a plurality of battery blocks are connected together via a side plate is referred to as a battery module).

[0059] In one battery module 500 in which three cell arrays 100 are arranged in a row, end brackets 400 are exposed along the end plates 300 on the front and rear, and one end bracket 400 is also exposed on the side bracket 210 between the end plates 300. The pack case 602 is provided with a rail-shaped mounting portion 640 corresponding to the fastening surfaces 410 of the end brackets 400 protruding from the front and rear of the battery module 500. The mounting portion 640 includes a pair of side mounting portions 642 coupled to or integrally formed with the side frame 620, and a center mounting portion 644 provided across the center of the base plate 610, which are arranged in parallel.

[0060] 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 collectively fixed to the pack case 602 by joining or coupling the end bracket 400 to the mounting portion 640 of the pack case 602 through the fastening holes 412.

[0061] 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 the upper flanges 330, 230 formed by bending at the upper ends of the end plates 300, thereby firmly adhering the cell array 100 to the base plate 610.

[0062] 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. The upper plate includes a pair of inlet / outlet adapters 616 that form an inlet / outlet for the cooling medium flowing through the cooling channels 614.

[0063] A thermally conductive thermal interface material (TIM) 618 may be interposed between the heat sink 612 of the base plate 610 and the contact surface between 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. The thermally conductive thermal interface material 618 has high thermal conductivity and serves as a filler for filling minute irregularities on the contact surface, thereby contributing to the rapid transfer of heat generated in the battery block 10 to the heat sink 612.

[0064] 5, the battery module 500 mounted in the pack case 602 is sealed by an upper cover 630 coupled to an upper edge of the side frame 620. In particular, in the battery pack 600 of the present invention, a venting duct 632 that forms an integrated flow path for a plurality of venting devices 114 arranged in a row on the upper surface of the cell array 100 is integrally formed in the upper cover 630.

[0065] Preferably, the venting duct 632 is integrally formed by a sintering process such as pressing the upper cover 630. In order to integrally form the venting duct 632, the upper cover 630 is bent to form a curved cross-sectional shape, and the mechanical rigidity of the upper cover 630 is improved compared to a conventional upper cover having a simple flat plate shape through the curved cross-sectional shape, and the battery block 10 inside the pack case 602 can be more effectively protected accordingly.

[0066] 6 and 7 are cross-sectional views of upper cover 630 to show the cross-sectional structure of venting duct 632. As shown in the drawings, venting duct 632 includes recessed portion 634 that is in close contact with the upper surface of rectangular cell 110 around venting device 114, and protruding portion 633 that forms a space surrounding venting device 114. Here, recessed portion 634 and protruding portion 633 are terms that refer to the relative depth difference when upper cover 630 is viewed from above, and it can be understood that the plane formed by the surface of protruding portion 633 corresponds to the reference surface of upper cover 630.

[0067] The recesses 634 on both sides of the protrusion 633 are in close contact with the upper surface of the prismatic cell 110, thereby isolating the space inside the protrusion 633 surrounding the venting device 114 from the outside. In addition, a heat-resistant insulating sheet 636 such as a mica sheet may be interposed between the recess 634 of the venting duct 632 and the upper surface of the prismatic cell 110 so as not to cover the venting device 114. The insulating sheet 636 thermally protects the contact surface between the recess 634 and the prismatic cell 110 when high-temperature gas, flames, particles, etc. are ejected due to the rupture of the venting device 114, thereby allowing airtightness to be maintained for a longer period of time.

[0068] The flow space inside the protrusion 633 formed by the venting duct 632 forms a passage through which the combustion products ejected from the venting device 114 move, and one cell array 100 has one venting duct 632. That is, the multiple rectangular cells 110 constituting one cell array 100 share one venting duct 632, and the venting ducts 632 assigned to each cell array 100 are separated from each other. This suppresses the propagation of thermal runaway generated in a certain battery block 10 to the surroundings, thereby preventing or delaying the spread to a thermal propagation phenomenon.

[0069] The protruding portion 633 of the venting duct 632 has one side facing the side frame 620 of the pack case 602 forming a duct outlet 635, while the opposite side forms a closed surface. With reference to FIGS. 6 and 8, one end of the protruding portion 633 adjacent to the side frame 620 is open, while the other end opposite thereto is closed. As a result, the combustion products flowing through the venting duct 632 are guided to flow in one direction toward the side frame 620. In addition, since the duct outlet 635 of the protruding portion 633 is connected to the venting outlet 622 provided in the side frame 620 of the pack case 602, the combustion products ejected from a certain battery block 10 are finally discharged to the venting outlet 622 of the pack case 602 along a predetermined path. In this manner, the combustion products emitted from the prismatic cell 110 that has experienced thermal runaway are discharged to the outside of the pack case 602 through a restricted, predetermined path, so that a safety design can be efficiently established for not only the battery pack 600 but also various devices equipped with the battery pack 600.

[0070] Meanwhile, according to the illustrated embodiment, electrode terminals 112 are disposed on both sides of the venting device 114 on the upper surface of the prismatic cell 110. Since electrical wiring between the multiple prismatic cells 110 constituting the cell array 100 and further the battery block 10 starts from the electrode terminal 112, it is necessary to secure a space required for the electrical wiring around the electrode terminal 112. For this reason, the upper cover 630 is provided with wiring ducts 638 that form a space surrounding the electrode terminals 112 of the cell array 100 on both sides of the venting duct 632, and it is preferable that the wiring ducts 638 are also integrally formed with the upper cover 630 by sintering.

[0071] 6 to 8, it is preferable that the wiring duct 638 is isolated from the entire venting duct 632 including the duct outlet 635. That is, in order to protect the electrical wiring from the combustion products flowing through the venting duct 632 in an emergency situation in which thermal runaway occurs when the venting device 114 is activated, the wiring duct 638 is disconnected from the venting duct 632. In particular, as shown in FIG. 6, one end of the wiring duct 638 adjacent to the side frame 620 is not on the same line as the outlet cross section of the duct outlet 635, so that the electrical wiring inside the wiring duct 638 is not exposed to the high-temperature combustion products discharged to the duct outlet 635.

[0072] Third embodiment 9 is a diagram showing a battery block 10 according to a third embodiment, and the battery block 10 according to the third embodiment is characterized in that it includes a heat absorption / venting pouch 240 as a safety means for dealing with various thermal problems. As shown in FIG 9, the heat absorption / venting pouch 240 may be disposed inside the side plate 200 and / or on the front and rear surfaces of the prismatic cell 110.

[0073] 9 and 10, which is a cross-sectional view taken along line "DD" in Fig. 9, the side plate 200 shown is made of a single plate bent into a U-shape with an open top to form a space inside. By bending the single plate into a U-shape with an open top, the side plate 200 is lightweight yet has excellent mechanical strength.

[0074] Moreover, 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.

[0075] The single plate bent into a U-shape has excellent durability and strength against compression and tension in the longitudinal direction L due to the bent structure, but may be relatively vulnerable to a force in the height direction H. The joining rib 220 improves rigidity against a force 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 riveting, etc.

[0076] Due to the structure of the side plate 200, i.e., the single plate structure bent into a U-shape and the structure of the mutually joined concave surfaces 222, the side plate 200 is lightweight yet has strong mechanical rigidity. 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 600, 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.

[0077] 9 and 11, which is a cross-sectional view taken along line "EE" in FIG. 9, 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.

[0078] 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.

[0079] 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.

[0080] 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.

[0081] 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.

[0082] Meanwhile, in one embodiment of the present invention, the absorbent material 242 may be a highly absorbent matrix, for example, an absorbent material 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 by processing a highly absorbent resin into a fiber form such as a nonwoven fabric. The highly absorbent matrix can accommodate a large amount of liquid, and therefore can significantly increase the heat capacity of the side plate 200.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] In one embodiment of the present invention, the liquid impregnated in the absorbent 242 may be water. Water is a substance that has the highest 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.

[0088] 9, heat absorption / venting pouches 240 may be disposed between the prismatic cells 110 and also on the front or rear surface of the outermost prismatic cell 110 (hereinafter, simply referred to as "between the prismatic cells") so as to contact the front and rear surfaces of the plurality of prismatic cells 110 constituting the cell array 100. The heat absorption / venting pouches 240 contact the front and rear surfaces of the prismatic cells 110 and more directly absorb the heat of the prismatic cells 110, thereby more effectively compensating for thermal problems in the battery block 10.

[0089] The heat absorption / venting pouch 240 disposed between the rectangular cells 110 has the above-mentioned configuration, except that the position of the fragile portion 246 on the heat-sealed sealing portion 244 may be limited to the upper edge. By disposing the fragile portion 246 on the upper edge of the heat absorption / venting pouch 240, steam generated when the fragile portion 246 bursts will be ejected into the protruding portion 633 of the venting duct 632, and the temperature of the high-temperature combustion products can be lowered below the combustion point through contact with the steam, greatly reducing the risk of ignition or fire.

[0090] Correspondingly, the heat insulating sheet 636 may be formed with a venting slit 637 penetrating therethrough at a position corresponding to the weak portion 246 of the heat absorbing / venting pouch 240. The venting slit 637 is for securing a flow path for the steam ejected through the weak portion 246, and the weak portion 246 and the corresponding venting slit 637 must be located within the flow space formed by the protruding portion 633 of the venting duct 632 in order to effectively cool the combustion products.

[0091] 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]

[0092] 10: Battery block 100: Cell array 110: Square cell 112: Electrode terminal 114: Venting equipment 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 622: Venting exit 630: Top cover 632: Venting duct 633: Convex 634: Recess 635: Duct exit 636: Heat insulation sheet 637: Venting slit 638: Wiring duct 640: Mounting part 642: Side mounting part 644: Center mounting part 650: Flange mounting part H: Height L: Longitudinal W: Width direction

Claims

1. a battery block including a cell array in which a plurality of rectangular cells each having a venting device on an upper surface thereof are aligned in a row, a pair of side plates disposed on both sides of the cell array, and a pair of end plates disposed on a front and a rear surface of the cell array, the widthwise ends of the end plates being fixed to side brackets provided on both longitudinal ends of the side plates, and the cell array being bound to one block; a pack case in which a plurality of the battery blocks are mounted; The upper cover of the pack case is a venting duct that forms an integrated flow path for the plurality of venting devices arranged in a row on the upper surface of the cell array.

2. The battery pack according to claim 1 , wherein the venting duct is integrally formed with the upper cover by sintering.

3. The vent duct is 3. The battery pack according to claim 1, further comprising: a recess that is in close contact with an upper surface of the prismatic cell around the venting device; and a protrusion that forms a space surrounding the venting device.

4. The battery pack according to claim 3 , wherein a heat insulating sheet is interposed between the recess of the vent duct and an upper surface of the prismatic cell.

5. The protrusion is The battery pack according to claim 3 , wherein one side of the pack case facing the side frame forms a duct outlet, and the other side forms a closed surface.

6. Electrode terminals are disposed on both sides of the venting device on the upper surface of the rectangular cell, The battery pack according to claim 5 , wherein wiring ducts that define spaces surrounding the electrode terminals on both sides of the venting duct are integrally formed with the upper cover by sintering.

7. The battery pack according to claim 6 , wherein the wiring duct is isolated with respect to the duct outlet.

8. The duct outlet is The battery pack according to claim 5 , which communicates with a venting outlet provided in a side frame of the pack case.

9. The cell array includes: a heat absorption / venting pouch disposed between the prismatic cells so as to contact the front and rear surfaces of the prismatic cells; the heat absorption / venting pouch hermetically contains an absorbent material impregnated with a liquid; the heat absorption / venting pouch has heat seals along its edges; The battery pack according to claim 4 , wherein the heat-sealed portion is provided on the heat-sealed portion with a weakened portion having a relatively low burst strength.

10. the weakened portion of the heat absorption / venting pouch is located at a top edge; The battery pack according to claim 9 , wherein the insulating sheet has a venting slit corresponding to the weak portion within a space formed by a convex portion of the venting duct.

11. The side plate is a single plate bent into a U-shape with an open upper end to form an internal space, The battery pack according to claim 4 , wherein the internal space includes a heat absorbing / venting pouch that hermetically houses a liquid-impregnated absorbent material.

12. The side plate is The bent single plate has concave surfaces on both sides, and at least one joining rib is provided along the longitudinal direction by joining the facing concave surfaces to each other, The battery pack according to claim 11 , wherein the heat absorption / venting pouch is inserted into an internal space defined by the joining ribs.

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