Battery pack

Abstract

Battery pack (300) comprising: a plurality of battery cells (110); a pack housing (310) accommodating the plurality of battery cells (110); a partition (330) located within the pack housing (310) and dividing an interior of the pack housing (310) to form a cell receiving space (381) in which the plurality of battery cells (110) are accommodated; an element receiving space (383) located within the pack housing (310) adjacent to the cell receiving space (381); and an insert element (370) located in the element receiving space (383) and comprising fire-resistant particles (371).

Description

BACKGROUND1. Field of InterestThe present disclosure relates to a battery pack. More particularly, the present disclosure relates to a battery pack to delay heat spread (TP) during thermal cycling of a battery cell.2. Description of the Prior ArtDue to fires and explosions occurring during use of lithium secondary batteries, social concerns have recently increased with regard to the safety of battery use. Based on these social concerns, one of the main development tasks of lithium secondary batteries has recently been to eliminate instability such as fires and explosions caused by thermal runaway of battery cells.Specifically, a battery module / pack includes an empty space other than the battery cells that are the power source. When a fire occurs due to an external impact or a problem with a battery cell, the flame may propagate to adjacent cells through the empty space, which increases damage caused by the fire. Since this risk of fire could be the greatest obstacle to the electric vehicle market, there is currently a research to reduce the spread of a fire.SUMMARY OF THE INVENTIONFirst, according to an aspect of the present disclosure, an object is to delay propagation of high temperature gas (e.g., exhaust gas) or heat within a battery pack due to thermal runaway of one or more battery cells provided within the battery pack.Second, according to another aspect of the present disclosure, an object is to vent high temperature gas generated in a battery cell that has undergone thermal runaway along an intended path.Third, according to still another aspect of the present disclosure, an object is to increase stability and life of a battery pack by increasing heat resistance or fire resistance.A battery pack according to the present disclosure may be widely applied in the field of green technology such as electric vehicles, battery charging stations, energy storage systems (ESS), and other battery-based photovoltaics and wind power. In addition, the battery pack according to the present disclosure may be used for eco-friendly mobility including electric vehicles and hybrid vehicles to prevent climate conversion by suppressing air pollution and greenhouse gas emissions.A battery pack according to the present disclosure may include: a plurality of battery cells; a pack case accommodating the plurality of battery cells; a partition wall located inside the pack case and partitioning an interior space of the pack case to form a cell accommodation space in which the plurality of battery cells are accommodated; an element accommodation space located adjacent to the cell accommodation space inside the pack case; and a plug member located in the element accommodation space and containing fire-resistant particles.According to an embodiment, the insert element may further contain a binder that binds the fire resistant particles together.According to an embodiment, the binder may melt above a predetermined allowable temperature, and the allowable temperature may be between 60° C. (degrees Celsius) and 800° C.According to an embodiment, a melting point of the refractory particles may be higher than the allowable temperature.According to an embodiment, the refractory particles may be bound by the binder to form an outer shape of the insert element.According to an embodiment, the insert member may further include an external material (an exterior material) that receives the refractory particles.According to an embodiment, the external material may melt above a predetermined allowable temperature, and the allowable temperature may be between 60° C. and 800° C.According to an embodiment, the external material may be formed into a predetermined shape.According to an embodiment, the external material may be formed of a flexible material that is deformable according to a space in which the insertion member is disposed.According to an embodiment, the refractory particles may include a porous material, and a porosity of the porous material may be 1% (percent) or more and 99% or less.According to an embodiment, the refractory particles may include one of silicon dioxide and an organic silicon compound or a combination thereof.According to an embodiment, the package case may include a package body having an opening in an upper part that receives the plurality of battery cells through the opening and that forms the cell receiving space and the element receiving space together with the partition wall, and a package cover coupled to the package body to close the opening.According to an embodiment, the package body may include a package body bottom side forming a bottom side of the package body and a package body side part extending from an edge of the package body bottom side and extending toward the package cover.According to an embodiment, the element accommodating space may include a first element accommodating space formed by the plurality of battery cells and the package body side part, and the insertion member may include a first insertion member located in the first element accommodating space.According to an embodiment, the element accommodating space may further include a second element accommodating space located between the plurality of battery cells and the pack cover, and the insertion member may further include a second insertion member located in the second element accommodating space and formed in a shape different from the first insertion member.According to an embodiment, the element accommodating space may further include a third element accommodating space located between the plurality of battery cells and the partition wall, and the insertion member may further include a third insertion member located in the third element accommodating space and formed in a different shape from the first insertion member and the second insertion member.According to an embodiment, the element accommodating space may further include a sub-element accommodating space located between the plurality of battery cells, the second insertion member, and the partition wall, and the insertion member may further include a sub-insertion member located in the sub-element accommodating space and formed in a shape different from the first insertion member and the second insertion member.According to an embodiment, the package body side part may include a first package body side surface and a second package body side surface extending from a pair of facing edges of edges of the package body lower side toward the package cover, and a first package connection side surface and a second package connection side surface connected to the first package body side surface and the second package body side surface and extending from another pair of facing edges of the package body lower side toward the package cover.According to an embodiment, a volume occupied by the refractory particles may be 1% or more of the volume of the element accommodation space.According to an embodiment, a plurality of the insertion members may be provided, and the plurality of insertion members may be formed into various shapes depending on their locations.According to an embodiment, the pack cover may further include a recessed part formed by recessed in a direction away from the pack body, the element accommodating space may include a recessed accommodating space formed in the recessed part, and the insertion element may include a cover insertion element located in the recessed accommodating space to surround at least a part of a detector that detects a current of the plurality of battery cells.According to an embodiment, the battery pack according to the present disclosure may further include a power terminal inserted through an arbitrary side surface of the first pack body side surface, the second pack body side surface, the first pack connection side surface, and the second pack connection side surface and electrically connecting the plurality of battery cells to an outside, and a control device located between the one side surface and the plurality of battery cells and controlling the plurality of battery cells, the element accommodating space may include a control device accommodating space in which the control device is located between the pack case and the partition wall, and the insertion element may include a control device insertion element located in the control device accommodating space to surround at least a part of the control device.First, according to an embodiment of the present disclosure, it is possible to delay propagation of high temperature gas or heat inside a battery pack due to thermal runaway of one or more battery cells provided inside the battery pack.Second, according to another embodiment of the present disclosure, it is possible to vent high temperature gas generated in the battery cell that has undergone thermal runaway along an intended path.Third, according to still another aspect of the present disclosure, it is possible to increase the stability and life of the battery pack by increasing a heat resistance or a fire resistance.BRIEF DESCRIPTION OF THE DRAWINGSFIG. 1 is an example of a battery pack according to the present disclosure. FIG. 2 is an example of a battery pack according to the present disclosure as viewed from above. FIG. 3 is another example of a battery pack according to the present disclosure as viewed from above. FIG. 4 is an exploded view of an example of a battery module included in a battery pack according to the present disclosure. FIG. 5 is another example of a battery pack according to the present disclosure. FIG. 6 is an example of a side view of a battery pack according to the present disclosure. FIG. 7 is an example of a male member according to the present disclosure. FIG. 8 is another example of a male member according to the present disclosure. FIG. 9 is yet another example of a male member according to the present disclosure.DETAILED DESCRIPTIONHereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. The configuration of an apparatus or a control method described below is intended to illustrate embodiments of the present disclosure, and is not intended to limit the scope of the present disclosure, and reference numerals identically used throughout the description represent identical components.Specific terms used in the present specification are for illustrative purposes only and are not used to limit the present disclosure to the exemplary embodiments.For example, expressions such as "the same" and "identical" not only indicate a strictly identical state but also indicate a state in which there is a tolerance or a difference in the degree to which the same function is obtained.For example, expressions indicating relative or absolute arrangements such as "in a direction", "along a direction", "parallel", "perpendicular", "centered", "concentric" or "coaxial" not only indicate the exact arrangements but also indicate a state of relative displacement with a tolerance or an angle or distance providing the same function.To describe the present disclosure, the following will be explained based on a spatially orthogonal coordinate system having an X axis, a Y axis, and a Z axis that are orthogonal to each other. Unless otherwise stated, a Z direction refers to a vertical direction, and an X direction (or a first direction) refers to any of the directions perpendicular to the vertical direction. Further, a Y direction (or a second direction) refers to a direction perpendicular to the Z direction and the X direction.However, the X direction, Y direction, and Z direction mentioned below are provided for the purpose of explanation, so that the present disclosure can be clearly understood, and it is understood that each direction may be defined differently depending on where the reference is placed.The use of terms such as "first", "second", and "third" before components mentioned below is intended to avoid confusion as to the components to which they relate and has nothing to do with the order, importance, or major-to-descendant relationship between the components. For example, an invention that includes only a second component without a first component may be practiced.As used herein, unless the context clearly indicates otherwise, singular terms include plural terms.FIG. 1 is an example of a battery pack 300 according to the present disclosure.Referring to FIG. 1, the battery pack 300 according to the present disclosure includes a plurality of battery cells 110 and a pack case 310 accommodating the plurality of battery cells 110.The plurality of battery cells 110 may be stacked and arranged in a predetermined stacking direction (e.g., in the X or Y direction). In addition, the plurality of battery cells 110 may be grouped in a predetermined number to form at least one battery group (or cell stack 100). The at least one battery pack may be located in a space partitioned inside the pack case 310.The pack case 310 may be formed of a metallic material and may house the plurality of battery cells 110 therein. The pack case 310 may include an opening 385 in an upper part, and may include a pack body 319 that receives the plurality of battery cells 110 through the opening 385, and a pack cover 315 coupled to the pack body 319 to close the opening 385.The pack cover 315 may form, with the pack body 319, an interior space that receives the plurality of battery cells.The package 319 may include a package bottom 3305 forming a bottom of the package 319 and a package side part 3301 extending from an edge of the package bottom 3305 and extending toward the package cover 315.The package bottom 3305 forms a bottom of the interior or the bottom of the package 319 and may support the plurality of battery cells 110.The package side part 3301 forms side surfaces of the inner space and may extend from edges of the package bottom 3305 toward the opening 385.Referring to FIG. 1, since the package body bottom 3305 is a square plate, the package body side part 3301 may include four side surfaces.In other words, the package body side part 3301 may include a first package body side surface 3301 cand a second package body side surface 3301 dthat extend from a pair of facing edges of the package body lower side 3305 toward the package cover 315, and a first package connection side surface 3301 aand a second package connection side surface 3301 bconnected to the first package body side surface 3301 cand the second package body side surface 3301 dand extend from a pair of facing edges of the package body lower side 3305 toward the package cover 315.When the shape of the package bottom surface 3305 changes, the number of edges of the package bottom surface 3305 may change, and thus the number of side surfaces of the package side part 3301 may also change accordingly.The battery pack 300 may further include a partition wall 330 for partitioning the internal space formed by the pack body 319 and the pack cover 315. The partition wall 330 may be a metal frame and may partition the internal space so as to be divided adjacent to each battery group. The partitioned internal space is referred to as a separate arrangement space ( 380, see FIG. 2 ), and the separate arrangement space 380 may include a cell accommodation space ( 381, see FIG. 2 ) accommodating the plurality of battery cells and an element accommodation space ( 383, see FIG. 2 ) located adjacent to the cell accommodation space 381. The cell accommodation space 381 and the element accommodation space 383 may be connected to each other.In addition, even when the internal space is partitioned, each separate space may not be an isolated space, but each separate space may be connected to each other. Unless otherwise specified in the present specification, even when the internal space is partitioned, the partitioned spaces are not isolated and separated spaces but spaces that may be connected to each other.FIG. 2 is an example of the battery pack 300 according to the present disclosure as viewed from above.Referring to FIG. 2, the plurality of battery cells 110 may be grouped according to the predetermined number to form the cell stack 100. The cell stack 100 may refer to an assembly in which the predetermined number of battery cells 110 are electrically connected using a first bus bar 170.Referring to FIG. 2, the cell stack 100 may be stacked in a predetermined stacking direction (e.g., in the X direction).The cell stack 100 may be located in the separate arrangement space 380 formed in the battery pack 300.The battery pack 300 according to the present disclosure may further include a housing cover 225 positioned between the cell stack 100 and the pack cover 315 to cover the cell stack 100 after the cell stack 100 is housed in the separate arrangement space 380. As a reference to explain the cell stack 100 exposed in FIG. 2, FIG. 2 illustrates an example of the battery pack 300 with a part of the accommodation covers 225 removed.As described above, the battery pack 300 may include the separate arrangement space 380 that accommodates the plurality of battery cells 110 in the partition. Further, the separate arrangement space 380 may include the cell accommodation space 381 accommodating the cell stack 100 and the element accommodation space 383 located adjacent to the cell accommodation space.The element accommodation space 383 refers to an empty space in the separate arrangement space 380 that occupies the cell accommodation space 381.In addition, the battery pack 300 according to the present disclosure may further include a power terminal 393 that electrically connects the exterior of the pack case 310 to the plurality of battery cells 110. More specifically, the battery pack 300 according to the present disclosure may further include the power terminal inserted through any one side surface of the first pack body side surface 3301 c, the second pack body side surface 3301 d, the first pack connection side surface 3301 a, and the second pack connection side surface 3301 band electrically connecting the plurality of battery cells 110 to the outside; and a control device ( 395, see FIG. 5 ) positioned between the one side surface ( 3301 a, 3301 b, 3301 c, 3301 d) and the plurality of battery cells ( 110) and controlling the plurality of battery cells 110.In addition, the battery pack 300 according to the present disclosure may include the first bus bar 170 electrically connecting the plurality of battery cells 110 grouped and stacked in the predetermined number, and a second bus bar 391 connecting the first bus bar 170 and the power terminal 393.The second bus bar 391 may electrically connect the cell stacks 100 by considering the cell stack 100 as a unit. The control device 395 may be located between the power terminal 393 and the second bus bar 391, and may acquire status information including a voltage of the plurality of battery cells 110 and control the plurality of battery cells 110.In addition, the partition wall 330 may form the separate arrangement space 380 by partitioning the inner space of the pack case 310. In other words, the cell accommodation space 381 and the element accommodation space 383 may be formed by the partition wall 330 and the pack case 310. To this end, the partition wall 330 may include a first frame 331 partitioning the internal space in the first direction and a second frame 339 partitioning the internal space in the second direction perpendicular to the first direction. In other words, the partition wall 330 may include the first frame 331 and the second frame 339 to horizontally and vertically partition the internal space formed by the pack case 310 as viewed from the opening 385.FIG. 3 is another example of the battery pack 300 according to the present disclosure as viewed from above.FIG. 2 shows the example in which the element accommodation space 383 is perpendicular to the stacking direction of the plurality of battery cells 110 or the stacking direction of the battery cells 110 constituting the cell stack 100. On the other hand, FIG. 3 shows an example in which the element accommodation space 383 is located side by side with the stacking direction.Referring to FIGS. 2 and 3, the element accommodation space 383 may be connected to the cell accommodation space 381, and the element accommodation space 383 refers to a space in the separate arrangement space 380 formed by the partition excluding the cell accommodation space 381. For illustrative purposes, the element receiving space 383 is shown excessively large.Referring to FIGS. 2 and 3, the element storage space 383 may be a space that takes into account convenience of assembly when the plurality of battery cells 110 is stored in the package body 319 and other elements connected to the plurality of battery cells 110. Therefore, the size of the element accommodation space 383 does not need to be abundant, but may be a space that is inevitably formed.When thermal runaway occurs in at least one battery cell 110 of the plurality of battery cells 110 and high temperature gas or flame propagates to the element accommodation space 383, the high temperature gas or flame can rapidly propagate through the element accommodation space 383 to other battery cells 110 and further to the entire battery pack 300.Therefore, it is necessary to retard or prevent the propagation of high temperature gas or flame through the element accommodating space 383. To this end, the battery pack 300 according to the present disclosure includes an insertion member ( 370, see FIG. 5 ) located in the member storage space 383.FIG. 4 is an exploded view of an example of a battery module 200 included in the battery pack 300 according to the present disclosure.Referring to FIG. 4, the battery module 200 may include the plurality of battery cells 110, the first bus bar 170 electrically connected to the plurality of battery cells 110, and a module case 210 accommodating the plurality of battery cells 110 and the first bus bar 170 therein.The module case 210 may include a module body 219 forming a part of a module space 280 accommodating the plurality of battery cells 110, and a module cover 215 coupled to the module body 219 to together form the module space 280.Within the module body 219, the plurality of battery cells 110 may be overlapped along a predetermined stacking direction (e.g., the X direction).More specifically, the module case 210 may further include a module body 219 including an opened top surface 2195 and accommodating the plurality of battery cells 110 through the opened top surface 2195, and a module cover 215 coupled to the module body 219 and closing the opened top surface 2195.Therefore, the module cover 215 may be coupled to the module body 219 to form an upper surface of the module space 280 or the upper surface of the module case 210. In other words, the module cover 211 is coupled to the module body 219 to close the opened upper surface 2195 of the module body 219, and forms the module space 280 together with the module body 219.The module space 280 is formed inside the module body 219 and may include a space that accommodates the cell stack 100.In addition, the module body 219 may be provided in a channel shape or U-shape having an open top. Referring to FIG. 2, two side surfaces 2197 and 2198 facing each other along the X direction of the side surfaces of the module body 219 may also be opened.In other words, the module body 219 may include a module body lower surface 2194 forming a lower surface of the module space 280 and module body side surfaces 2191 and 2192 extending toward the module cover 211 from edges (not shown) provided side by side along the stacking direction of edges of the module body lower surface 2194. The free end of the module body side surface (2191 or 2192) may be bent to form a flange (not shown). This is for easy coupling to the module cover 211.Referring to FIG. 4, the height of the module body 219 may be less than the height of the plurality of battery cells 110. However, this is merely an example, and the height of the module body 219 may be greater than the height of the plurality of battery cells 110.Referring to FIG. 4, a thermal barrier member 119 is shown to be provided at one end of the cell stack 100, but this is merely an example. In other words, the cell stack 100 may further include buffer elements or thermal barrier elements 119 located between the plurality of battery cells 110. The thermal barrier elements 119 may be located between at least some of the plurality of battery cells 110.The thermal barrier member 119 may serve as a thermal barrier in the case of thermal runaway of a battery cell 110 to prevent flame or heat from propagating to adjacent battery cells 110.The plurality of battery cells 110 and the plurality of thermal barrier members 119 may be provided and stacked in a predetermined position. For example, with reference to FIG. 2, an example is illustrated in which long edges of the plurality of battery cells 110 are arranged side by side with the Y direction. Therefore, the plurality of battery cells 110 and the plurality of thermal barrier members 119 are to be located so as to overlap in the X direction.The thermal barrier member 119 may be formed of a refractory (refractory or flame retardant) material. For example, the thermal barrier member 119 may include a fire-resistant polymer or a material such as mica.In addition, referring to FIG. 4, the battery module 200 may further include end plates 212 and 213 at both ends of the cell stack 100 along the stacking direction. The end plates 212 and 213 may be provided at both ends of the cell stack 100 or may be connected to the two side surfaces 2197 and 2198 of the module body 219.The end plates 212 and 213 are intended to prevent the two side surfaces of the cell stack 100 from being exposed to the outside.In addition, the battery module 200 may include first bus bars 171 and 172 electrically connected to the plurality of battery cells 110. Further, the battery module 200 may further include bus bar frames 151, 152, and 155 that support the first bus bars 171 and 172 and the plurality of battery cells 110. The first bus bars 171 and 172 and the bus bar frames 151, 152, and 155 may be collectively referred to as a bus bar assembly 150. In other words, the bus bar assembly 150 may include the first bus bars 171 and 172 electrically connected to the plurality of battery cells 110.The first bus bars 171 and 172 may connect the stacked plurality of battery cells 110 in series or in parallel so that a predetermined voltage may be output. Further, the battery pack 300 may further include the second bus bar 391 located inside the pack case 310 to electrically connect the first bus bars 171 and 172 and the power terminal ( 393 see FIG. 6 ). The second bus bar 391 may connect between the battery module 200 and the power terminal 393 and between the battery modules 200 so that a voltage above a predetermined voltage is output to the battery pack 300. To this end, the battery pack 300 may further include the control device ( 395, see FIG. 5 ) positioned between the second bus bar 391 and the power terminal 393 to control the plurality of battery cells 110.The bus bar frames 151, 152, and 155 may be electrically connected to the outside, and may store (or charge) electric energy stored in the plurality of battery cells 110 or supply (or discharge) electric energy stored in the plurality of battery cells 110 to the outside.The bus bar assembly 150 may include the first bus bar frame 151 and the second bus bar frame 152 extending along the stacking direction of the plurality of battery cells 110 with the plurality of battery cells 110 interposed therebetween.Further, the bus bar assembly 150 may further include a support frame 155 positioned on a side of the bus bar assembly 150 and connecting the first bus bar frame 151 and the second bus bar frame 152.Referring to FIG. 4, the bus bar assembly 150 may be located on each side of the plurality of battery cells 110. On the other hand, the bus bar assembly 150 may be located on one side (e.g., a top side) of a main body 115.In other words, if each of cathode and anode electrodes provided in the plurality of battery cells 110 is connected to one of the first bus bar 170 and the second bus bar 391, the first bus bar 170 and the second bus bar 391 may be located at any location.In addition, the support frame 155 may play a role in preventing and supporting deformation of the first bus bar frame 151 and the second bus bar frame 152. Further, a part of an electrical device for sensing and controlling the plurality of battery cells 110 may be disposed on the support frame 155.Referring to FIG. 4, the shape of the bus bar assembly 150 may be a tunnel shape. Further, the length of the first bus bar frame 151 and the second bus bar frame 152 along the stacking direction may be longer than the length of the support frame 155.In other words, the support frame 155 may be connected to the first bus bar frame 151 and the second bus bar frame 152 to cover an upper part of the plurality of battery cells 110. The support frame 155 may cover only a portion of the upper part of the plurality of battery cells 110 or may cover the entire upper part.The first bus bar 170 and the second bus bar 391 may be positioned farther away from the plurality of battery cells 110 than the first bus bar frame 151 and the second bus bar frame 152, respectively. In other words, the first bus bar 170 and the second bus bar 391 may be positioned closer to the module body side surfaces 2191 and 2192 than the first bus bar frame 151 and the second bus bar frame 152.In addition, the battery module 200 may further include a heat dissipation part 295 positioned between the module body bottom 2194 and the plurality of battery cells 110 to transfer heat generated by the plurality of battery cells 110 to the outside of the battery module 200. The heat dissipation part 295 may be made of an adhesive material having thermal conductivity, such as a heat dissipation adhesive. Therefore, by the heat dissipation part 295, it may be possible to connect the plurality of battery cells 110 to the module body lower surface 2194. To this end, the heat dissipation member 295 may be sprayed or applied to the module body bottom 2194.FIG. 5 is another example of the battery pack 300 according to the present disclosure.As described above, when thermal runaway occurs in any battery cell 110 of the plurality of battery cells 110, high temperature gas (exhaust gas) or flame may propagate from the battery cell 110 in which the thermal runaway has occurred to other adjacent battery cells 110.The high temperature gas or the flame may not only propagate or be ejected to the battery module 200 but also to the interior of the pack case 310. The battery pack 300 according to the present disclosure may have a cell-to-pack (CTP) structure without the battery module 200 (see FIG. 1 ). Therefore, there is a possibility that the high temperature gas or the flame can rapidly spread in the internal space along the element accommodation space 383. The battery pack according to the present disclosure can delay (attenuate) the propagation of high temperature gas or flame to another location by positioning the insert member 370 in the member accommodation space 383 to reduce the empty space in the member accommodation space 383.To this end, the battery pack 300 according to the present disclosure may include the plurality of battery cells 110, the pack case 310 accommodating the plurality of battery cells 110, the partition wall 330 located inside the pack case 310 and partitioning the interior of the pack case 310 to form the cell accommodation space 381 in which the plurality of battery cells 110 are accommodated, the element accommodation space 383 located adjacent to the cell accommodation space 381 in the pack case 310, and the insert member 370 located in the element accommodation space 383 and containing fire-resistant particles.The insert member 370 may include a binder 373 that binds the refractory particles 371 together.Alternatively, the insert member 370 may further include an external material ( 372, see FIG. 8 ) that receives the refractory particles 371. In other words, the refractory particle 371 may be accommodated in the external material 372, which restricts the movement of the refractory particle 371 without the binder 373.The external material 372 may be formed into a predetermined shape corresponding to the element accommodating space 363 to be inserted into the element accommodating space 363.Alternatively, the external material 372 may be formed of a flexible material deformable in correspondence with the element accommodation space 383 in which the insert element 370 is disposed. In other words, the external material 372 may be formed of a flexible material without a specific shape. The external material 372 will be described later with reference to FIGS. 8 and 9.The insert member 370 may be positioned in the member receiving space 383 to fill the member receiving space 383. In order to simplify a process of positioning the insertion member 370 in the member accommodating space 383, the insertion member 370 may be formed in a size and shape that can be inserted into the member accommodating space 383. For example, when the element accommodating space 383 is a hexahedron having a length of one side of 5 cm, the insertion element 370 may be formed into a hexahedron having a length of an edge of 5 cm or less. This is because an assembly error between the insert member 370 and the member accommodation space 383 is taken into account.Further, the shape of the insertion member 370 may vary depending on the shape of the battery pack 300 and the position of the member storage space 383.Specifically, the element accommodation space 383 may include a first element accommodation space 383 aformed by the plurality of battery cells 110 and the package body side part 3301, and the insertion element 370 may include a first insertion element 3701 located in the first element accommodation space 383 a.As a reference, since the first insertion member 3701 corresponding to the shape of the first member accommodation space 383 ais positioned at the position of the first member accommodation space 383 a, different reference numerals are simultaneously given at the same position. Unless otherwise stated, the following drawings are shown for other element receiving spaces and other insertion elements in a similar manner.As described above, the shape of the first insertion member 3701 may vary depending on where it is located inside the battery pack 300. Referring to FIG. 5, when a side of the pack case 310 that is smaller than other sides of the pack case 310 is referred to as a front side and its opposite side is referred to as a back side, the size and shape of the first element accommodation space 383 aadjacent to the front side may be different from the size and shape of the first element accommodation space 383 aadjacent to the back side. Therefore, the shape of the first insertion member (3701, I3) inserted into the first member accommodating space 383a adjacent to the front side may be different from the shape of the first insertion member (3701, 11) inserted into the first member accommodating space 383a adjacent to the rear side and the shape of the first insertion member (3701, I2) positioned therebetween.Referring to the enlarged drawing of the region A of the first insert member 3701, the first insert member 3701 may include the refractory particles 371 and the binder 373 that bonds the refractory particles 371 and forms the outer shape of the first insert member. This can also be applied to other insertion members described later.In other words, by bonding the refractory particles 371 by the bonding agent 373, the insert member 370 may form an outer shape or a predetermined three-dimensional shape of the insert member 370.Referring to FIG. 5, a plurality of the refractory particles 371 may be provided. For reference, the refractory particle 371 is shown in an exaggerated size and simplified in shape into a sphere for explanation, but may have an amorphous shape.Preferably, the insert member 370 may include the plurality of refractory particles 371 and the binder 373 binding the plurality of refractory particles 371 among the plurality of refractory particles 371 to form the predetermined three-dimensional shape.The plurality of refractory particles 371 may be solid fillers provided in the form of solid particles, powders, granules, pellets or beads. This serves to prevent or retard flame propagation or heat propagation through the element accommodation space 383 in the case of thermal runaway of any battery cell 110.The size of the refractory particle 371 may be micro-sized. These micro-sized refractory particles 371 may be referred to as microspheres or microgranules.The size of the refractory particle 371 may preferably be 2 μm (micrometers) or more, and may be less than or equal to the length or thickness of a battery cell 110 along the stacking direction.The size of the refractory particle 371, when a spherical shape is assumed, may be the size of the diameter, the radius being the distance from the center (or center of gravity) of the refractory particle 371 to the outermost outer periphery. Therefore, the size of the refractory particle 371 may be the maximum outer diameter of the refractory particle 371. Alternatively, the size of the refractory particle 371 may be an average value calculated by measuring the refractory particle 371 in multiple directions. This may also be applied when the refractory particle 371 is in the form of a particle.The reason why the size of the refractory particle 371 should be 2 μm or more is to take into account a void of a weld bead (not shown) formed in a part welded and coupled inside the battery pack (e.g., the part in which the first bus bar 170 and the plurality of battery cells are coupled). This is because, when the size of the refractory particle 371 is smaller than the cavity of the weld bead, it may unintentionally move from the element accommodation space 383 through the cavity of the weld bead to the cell accommodation space 381.Therefore, the size of the refractory particle 371 is allowed to be larger than the size of the void formed in the weld bead.Further, the refractory particles 371 are not necessarily defined by a single size or material, but may be in the form of a mixture of refractory particles 371 of different sizes or materials.The melting point of the refractory particle 371 may preferably be higher than a preset allowable temperature (or a predetermined temperature) described later.The binder 373 may begin to melt when the allowable temperature is reached. For example, the allowable temperature may be between 60° C. (degrees Celsius) and 800° C. As another example, the allowable temperature may be 200° C.Therefore, the melting point of the refractory particle 371 should be higher than the allowable temperature. In other words, the melting point of the refractory particle 371 may be higher than the temperature at which the binder 373 starts melting.Further, the melting point of the refractory particle 371 may be higher than the ignition point of the plurality of battery cells 110. The ignition point of the plurality of battery cells 110 may be the temperature at which venting occurs in the battery cells 110. Alternatively, it may be the temperature of the electrolyte contained inside the battery cell 110 when the case of the battery cell 110 is damaged or opens in a thermal runaway situation.Therefore, when any of the battery cells 110 starts undergoing thermal runaway, the binder 373 starts melting, but the refractory particle 371 can maintain its solid shape. This is to prevent the fire-resistant particle 371 from burning or melting.For example, even if thermal runaway of the battery cell 110 occurs, the refractory particle 371 will not burn or melt, and the outer shape of the refractory particle 371 can be maintained without significant change.The refractory particle 371 may include a porous material. The porous material is a material that contains pores inside its structure. The shape of the pores may be irregular or amorphous. In particular, the refractory particles 371 may comprise a silica gel in particulate or powder form.For example, the refractory particles 371 may include a porous material, and the porosity of the porous material may be greater than or equal to 1% (percent) and less than or equal to 99%.As another example, the porosity of the refractory particles 371 may be greater than or equal to 20% and less than or equal to 30%.In addition, the refractory material may be an inorganic compound. In other words, the refractory particle 371 may include a refractory material formed of an inorganic compound. The inorganic compound may be alum (K 2 SO 4 ·Al 2( SO 4)3 ·24H 2 O), borax (Na 2 B 4 O 7 ·10H 2 O), lime water (Ca(OH) aqueous 2- solution), quicklime (CaO), milk of lime (white emulsion prepared by mixing Ca(OH)2 with water), hydrated lime (Ca(OH)2), Washing soil (Na 2 CO 3.10 H 2 O), apatite (Ca 5( PO 4)3 OH), baking powder (a mixture of NaHCO 3 and salts of tartaric acid), baking soda (NaHCO 3), sodium thiosulfate pentahydrate (Na 2 S 2 O 3 ·5H2O), silica (or silica (SiO2)), alumina (or alumina (Al2O3)), Calcium oxide (CaO), calcium sulfate (CaSO 4), calcium chloride (CaCl 2), sodium carbonate (Na 2 CO 3), potassium chloride (KCl), magnesium oxide (MgO), zirconium oxide (ZrO 2), chromium oxide (Cr 2 O 3), aluminum hydroxide (Al(OH) 3), antimony trioxide (Sb 2 O 3), antimony pentoxide (Sb2O5), magnesium hydroxide (Mg(OH)2), any compound, which is selected from the group consisting of a zinc borate compound, a phosphorus compound, a nitrogen-based guanidine compound or a molybdenum compound, or a mixture thereof.For example, assuming that the refractory particle 371 is formed of silica (silica), and considering the melting point of silica (1713° C. (degrees Celsius)), the refractory particle 371 can minimize propagation of the heat or the exhaust gas generated when thermal runaway occurs to other locations. In addition, in the situation of thermal runaway of the battery cell, the refractory particle 371 remains unchanged in shape.As another example, the refractory particle 371 may be formed of silica gel. The silica gel is a powder-like porous material prepared by treating an aqueous solution of sodium silicate (Na2SiO3) with an acid. More specifically, it can be obtained by mixing sodium silicate and an aqueous inorganic acid solution (e.g., sulfuric acid) to form a silica hydrosol and then curing the hydrosol into a hydrogel. In consideration of the above-described typical production method of the silica gel, the main component (component making up 50% or more) of the silica gel is silica, and other components may further contain alumina, iron(III) oxide (Fe 2 O 3 or iron(III) oxide), or sodium. Therefore, the melting point of the silica gel may be about 1600° C. or higher.Preferably, the silica gel may contain 90% or more of silica. Further, since the silica gel is a porous material, the porosity of the refractory particles 371 may be 20% or more and 30% or less.In addition, the refractory particle 371 may contain either silica or an organosilicon compound, or a combination thereof.The organosilicon compound may refer to a compound in which silicon is bonded to an organic group. An example of the organosilicon compound is silicone foam. The silicone foam may be injected into the external material (or packaging material) and formed into a foamed form, or may be used, as shown in Figs. 6 and 7, by filling the external material (or packaging material) with a foam cured into a crawler form. However, this is merely an example, and the organosilicon compound is not limited to the silicone foam in the present disclosure.The binder 373 may melt at or above a preselected allowable temperature. In other words, when thermal runaway occurs in at least one battery cell 110 among the plurality of battery cells 110 and the temperature increases, the temperature around the battery cell 110 in which thermal runaway occurs increases. Here, the binder 373 may start melting when the temperature of the binder 373 reaches the allowable temperature. For example, the allowable temperature may be between 60° C. and 800° C.As another example, the allowable temperature may be 200° C.When the binder 373 melts above the allowable temperature, the outer shape of the insert member 270 is not maintained. Accordingly, at least some of the plurality of refractory particles 371 that have maintained a cylindrical shape by the binder 373 can be changed to a freely movable state.In other words, when the binder 373 melts above the allowable temperature, the refractory particles 371 may be individually scattered. In general, unless there is a large external impact, the refractory particles 371 can be stacked by their own weight inside the element accommodating space 383 from the bottom. In other words, when the binder 373 melts above the allowable temperature and the adhesiveness of the refractory particles 371 is released, the refractory particles 371 or a portion of the insert member 370 that has not yet melted may be stacked on the package body lower surface 3305 by its own weight. When the binder 373 is completely melted, the refractory particles 371 will fill the element accommodating space 383 from the package body bottom 3305 by their own weight.Even when the binder 373 is completely melted, in order for the refractory particles 371 to perform the function of delaying the spread of high-temperature gas or flame, the volume occupied by the refractory particles 371 in the element accommodation space 383 may be 1% or more of the volume of the element accommodation space 383.Therefore, regardless of the shape in which the insert member 370 is formed, the volume of the refractory particles 371 may be 1% or more of the volume of the member accommodation space 383 in which the insert member 370 is positioned.In other words, the volume occupied by the refractory particles 371 may be 1% or more of the volume of the element accommodation space 383.This is because, considering the volume of the element storage space 383, even if the volume of the refractory particles 371 is only 1% of the volume of the element storage space 383, it is possible to delay or block the thermal propagation occurring inside the battery pack 300.On the other hand, the insert member 370 can be formed into a desired shape by the bonding agent 373, and the moisture-proof or moisture-proof effect of the insert member 370 can be improved by obtaining the effect of coating the outer surface of the insert member 370 with the bonding agent 373.The material of the binder 373 may be a polymer such as resin. Further, the binder 373 may also be a heat-resistant or flame-retardant material that does not melt to the permissible temperature.In addition, the refractory particle 371 may be formed of materials other than silica gel as long as they have porosity and flame retardancy (heat resistance or fire resistance).As another example, the fire resistant particle 371 may refer to a polymer material having a V-0 rating in the 94V (Vertical Burning) test of UL (Underwriter's Laboratory), which is a flame retardant standard for polymer materials.In particular, the fire resistant particle 371 may include a flame retardant polymer. The flame retardant materials contain phosphorus-based, halogen-based, and inorganic flame retardants, and in the case of phosphorus-based flame retardant materials, may preferably contain phosphate compounds, phosphonate compounds, phosphinonate compounds, phosphine oxide compounds, phosphazene compounds, and metal salts thereof. They may be used alone or in a mixture of two or more.As another specific embodiment, the phosphorus-based flame retardants may be, but are not limited to, diphenyl phosphate, diaryl phosphate, triphenyl phosphate, tricresyl phosphate, trizyrenyl phosphate, tri(2,6-dimethylphenyl) phosphate, tri(2,4,6-trimethylphenyl) phosphate, tri(2,4-ditertmerybutylphenyl) phosphate, tri(2,6-dimethylphenyl) phosphate, bisphenol A bis(diphenyl phosphate), resorcinol bis[bis(2,6-dimethylphenyl) phosphate], resorcinol bis[bis(2,4-diterybutylphenyl) phosphate], hydroquinone bis[bis(2,6-dimethylphenyl) phosphate], hydroquinone bis[bis(2,4-dimerybutylphenyl) phosphate], or oligomeric phosphoric ester compounds. They may be used alone or in the form of a mixture of two or more.The binder 373 may fill a plurality of voids (not shown) formed between contacts of the refractory particles 371 and coat the outer surface of the insert member 370.In addition, the battery pack 300 may further include a control device 395 for controlling the plurality of battery cells 110. The control device 395 may be located between the power terminal 393 (see FIG. 2 ) and the second bus bar 391 (see FIG. 2 ). The controller 395 determines the voltage, current, or temperature of the plurality of battery cells 110 and may control charging and discharging of the plurality of battery cells 110.FIG. 6 is an example of a side view of the battery pack 300 according to the present disclosure.Referring to FIG. 6, the element storage space 383 may include a second element storage space 383 blocated between the plurality of battery cells 110 and the pack cover 315 and a third element storage space 383 clocated between the plurality of battery cells 110 and the partition wall 330.Further, the element accommodation space 383 may further include a sub-element accommodation space 383 dlocated between the plurality of battery cells 110, the second insertion element 3702, and the partition wall 330.In addition, the element accommodating space 383 may include an embedded accommodating space 383 eformed in an embedded part 3195 formed by at least a portion of the pack cover 315 embedded in a direction away from the pack body 319.In addition, the element accommodating space 383 may further include a controller accommodating space 383 fin which the controller 395 is located between the pack case 310 and the partition wall 330.And, the insertion member 370 may be inserted into each of the second member accommodating space 383 b, the third member accommodating space 383 c, the sub-member accommodating space 383 d, the recessed accommodating space 383 e, and / or the control device accommodating space 383 f.Specifically, the insertion member 370 may further include the second insertion member 3702 that is located in the second member accommodation space 383 band formed in a shape different from that of the first insertion member 3701.In addition, the insertion member 370 may further include a third insertion member 3703 that is located in the third member accommodating space 383 cand is formed by the bonding agent 373 but is formed in a different shape from the first insertion member 3701 and the second insertion member 3702.In addition, the insert member 370 may further include a sub-insert member 3704 that is located in the sub-member accommodation space 383 dbut formed in a different shape from the first insert member 3701 and the second insert member 3702.The insertion member 370 may include a cover insertion member 3705 located in the recessed receiving space 383 eto surround at least a portion of a detector that detects the current of the plurality of battery cells 110.Further, the insert member 370 may further include a controller insert member 3706 located in the controller accommodating space 383 fso as to surround at least a part of the controller 395.In other words, a plurality of the insertion members 370 may be provided, and the plurality of insertion members 3701 to 3706 may be formed in various shapes depending on their locations.Referring to FIGS. 1 and 6, the battery pack 300 may further include a power terminal inserted through an arbitrary side surface of the first pack body side surface 3301 c, the second pack body side surface 3301 d, the first pack connection side surface 3301 a, and the second pack connection side surface 3301 band electrically connecting the plurality of battery cells 110 to the outside, and the control device 395 located between the one side surface (3301 a, 3301 b, 3301 c, 3301 d) and the plurality of battery cells 110 and controlling the plurality of battery cells 110.The controller accommodating space 383 frefers to the remaining space except the space occupied by the controller 395, and the controller inserting member 3706 may be located in the controller accommodating space 383 fso as to surround at least a part of the controller 395.FIG. 7 is an example of the insert member 370 according to the present disclosure.Specifically, FIG. 7 shows an example of how to mount the battery pack 300 by retracting the insertion member 370 into the member storage space 383. Figs. 5 and 6 illustrate the element accommodating space 383 and the insert element 370 in a simplified manner for explanation. Therefore, it may be difficult in reality to position the insert member 370 having a shape matching the member accommodation space 383 due to interference with other members in the member accommodation space 383.For example, the battery pack 300 may further include a wiring 399 connecting the plurality of battery cells 110, a detector 397, and the controller 395. In the case where the wiring 399 is located in any of the element accommodating spaces 383, it may be difficult to easily mount the insert element 370 that matches the shape of the space.In other words, due to the volume occupied by the wiring 399 in the element accommodation space 383, at the time of inserting the insert element 370, interference with the wiring 399 may occur. Accordingly, the insertion member 370 may not be integrally formed so as to match the shape of the member accommodation space 383 corresponding to the insertion member 370, but may be formed of plural parts in consideration of interference with the wiring 399.In other words, the insertion member 370 may be formed by combining a plurality of parts 370 aand 370 b.Referring to FIG. 7, in the case where the insertion member 370 cannot be easily inserted from top to bottom due to interference with the wiring 399, the insertion member 370 may be formed by combining the first part 370 aand the second part 370 b, which may be combined with the first part 370 a, to form a passage through which the wiring 399 passes. This can be applied equally to all insert elements.FIG. 8 is another example of the insert member 370 according to the present disclosure.The insertion member 370 must have a shape corresponding to the member accommodating space 383 to be placed in the member accommodating space 383, or must be deformed in response to the shape of the member accommodating space 383.For this purpose, since the plurality of refractory particles 371 are bound by the binder 373, the insert member 370 may be formed to have a shape corresponding to the member accommodation space 383.Alternatively, the insert member 370 may further include the external material 372 that receives the fire-resistant particle 371. In other words, the refractory particle 371 may be accommodated in the external material 372, which restricts the movement of the refractory particle 371 without the binder 373.Further, the external material 372 may be formed of a material and in a thickness that may have a preselected three-dimensional shape or external shape. For example, the external material 372 may be formed of a polymer material such as polypropylene (PP) or polyethylene (PE).FIG. 8 illustrates the insert member 370 as an example using FIG. 7, but the feature of the refractory particle 371 accommodated in the external material 372 may be applied to all other types of insert member 370.In other words, the first insertion member 3701, the second insertion member 3702, the third insertion member 3703, the sub insertion member 3704, the cover insertion member 3705, and the control device insertion member 3706 may also be in the form of the refractory particles 371 and the external material 372 that receives the refractory particles 371.Further, when the internal temperature of the battery pack 300 is increased by the thermal runaway of the battery cell 110, the external material 372 may be melted, and the refractory particles 371 accommodated in the external material 372 may be exposed.For this purpose, the melting point of the refractory particle 371 needs to be higher than the allowable temperature. In other words, the melting point of the refractory particle 371 may be higher than the temperature at which the external material 372 starts melting.Accordingly, the melting point of the refractory particle 371 may preferably be higher than a preset allowable temperature (or predetermined temperature) described below. Alternatively, the external material 372 may begin to melt when the allowable temperature is reached. For example, the allowable temperature may be between 60° C. and 800° C.As another example, the allowable temperature may be 200° C.In the present disclosure, the allowable temperature of the external material 372 and the allowable temperature of the binder 373 are described as being within the same range. However, the allowable temperature of the external material 372 and the allowable temperature of the binder 373 may overlap only in a part of the range, and the upper or lower limit temperature may be different from each other.FIG. 9 is another example of the insert member 370 according to the present disclosure.Referring to FIG. 9, the external material 372 may be formed of a flexible material. In other words, unlike FIG. 8, the external material 372 may be formed of a flexible material that is deformable in response to the space in which the insertion member 370 is located.For example, the external material 372 may be formed of polypropylene (PP) or polyethylene (PE) material, but the thickness of the external material 372 may be smaller than a thickness capable of forming the three-dimensional shape, so that it may have flexibility.Therefore, the insertion member 370 can be deformed corresponding to the member accommodation space 383 in which the insertion member 370 is placed when the battery pack 300 is mounted.In other words, the insertion member 370 may be deformed and arranged according to the shapes of the first member accommodation space 383 aand the second member accommodation space 383 b, the third member accommodation space 383 c, the sub-member accommodation space 383 d, the recessed accommodation space 383 e, and the controller accommodation space 383 f.The present disclosure may be embodied in various forms and is not limited to the above-described embodiments. Therefore, when a modified embodiment includes a component of the claims of the present disclosure, it should be considered to fall within the scope of the present disclosure.The present disclosure relates to a battery pack including a plurality of battery cells, a pack case accommodating the plurality of battery cells, a partition wall located inside the pack case and partitioning an interior space of the pack case to form a cell accommodation space in which the plurality of battery cells are accommodated, an element accommodation space located adjacent to the cell accommodation space inside the pack case, and a plug member located in the element accommodation space and including fire-resistant particles.

Claims

A battery pack (300) comprising: a plurality of battery cells (110); a pack case (310) accommodating the plurality of battery cells (110); a partition wall (330) located inside the pack case (310) and partitioning an interior space of the pack case (310) to form a cell accommodation space (381) in which the plurality of battery cells (110) are accommodated; an element accommodation space (383) located inside the pack case (310) adjacent to the cell accommodation space (381); and an insert member (370) located in the element accommodation space (383) and including fire-resistant particles (371).The battery pack (300) according to claim 1, wherein the insertion member (370) further comprises a binder (373) that bonds the refractory particles (371) together.The battery pack (300) according to claim 1 or 2, wherein the binder (373) melts above a predetermined allowable temperature, and the allowable temperature is between 60°C (degrees Celsius) and 800°C, and / or wherein a melting point of the refractory particles (371) is higher than the allowable temperature.The battery pack (300) according to claim 2 or 3, wherein the refractory particles (371) are bonded by the bonding agent (373) to form an outer shape of the insert member (370).The battery pack (300) according to any one of claims 1 to 4, wherein the insertion member (370) further comprises an external material (372) that receives the refractory particles (371), and / or wherein the external material (372) melts above a predetermined allowable temperature, and the allowable temperature is between 60°C and 800°C.The battery pack (300) according to claim 5, wherein the external material (372) is formed of a flexible material deformable in accordance with a space in which the insertion member (370) is disposed.The battery pack (300) according to any one of claims 1 to 6, wherein the refractory particles (371) include a porous material, and a porosity of the porous material is 1% (percent) or more and 99% or less, and / or wherein the refractory particles (371) include one of silica or an organic silicon compound, or a combination thereof.The battery pack (300) according to any one of claims 1 to 7, wherein the pack case (310) includes: a pack body (319) having an opening (385) in an upper part, accommodating the plurality of battery cells (110) through the opening (385), and forming the cell accommodation space (381) and the element accommodation space (383) together with the partition wall (330); and a pack cover (315) coupled to the pack body (319) to close the opening (385), wherein the pack body (319) optionally includes: a pack body lower surface (3305) forming a lower surface of the pack body (319); and a pack body side part (3301) extending from an edge of the pack body lower surface (3305) and extending toward the pack cover (315).The battery pack (300) according to claim 8, wherein the element accommodation space (383) includes a first element accommodation space (383a) formed by the plurality of battery cells (110) and the pack body side part (3301), and the insertion element (370) includes a first insertion element (3701) located in the first element accommodation space (383a), optionally wherein the element accommodation space (383) further includes a second element accommodation space (383b) located between the plurality of battery cells (110) and the pack cover (315), and the insertion element (370) further includes a second insertion element (3702) located in the second element accommodation space (383b) and formed in a different shape from the first insertion element (3701).The battery pack (300) according to claim 8 or 9, wherein the element accommodation space (383) further includes a third element accommodation space (383c) located between the plurality of battery cells (110) and the partition wall (330), and the insertion member (370) further includes a third insertion member (3703) located in the third element accommodation space (383c) and formed in a different shape from the first insertion member (3701) and the second insertion member (3702).The battery pack (300) according to claim 9 or 10, wherein the element accommodation space (383) further includes a sub-element accommodation space (383d) located between the plurality of battery cells (110), the second insertion element (3702), and the partition wall (330), and the insertion element (370) further includes a sub-insertion element (3704) located in the sub-element accommodation space (383d) and formed in a different shape from the first insertion element (3701) and the second insertion element (3702).The battery pack (300) according to any one of claims 8 to 11, wherein the pack body side part (3301) includes: a first pack body side surface (3301c) and a second pack body side surface (3301d) that extend from a pair of facing edges of edges of the pack body lower side (3305) toward the pack cover (315); and a first pack connection side surface (3301a) and a second pack connection side surface (3301b) that are connected to the first pack body side surface (3301c) and the second pack body side surface (3301d) and extend from another pair of facing edges of the pack body lower side (3305) toward the pack cover (315).The battery pack (300) according to any one of claims 1 to 12, wherein a volume occupied by the refractory particles (371) is 1% or more of the volume of the element storage space (383).The battery pack (300) according to any one of claims 1 to 13, wherein a plurality of the insertion members (370) is provided, and the plurality of insertion members (370) are formed into different shapes depending on their locations.

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