Cell assembly and battery pack including same

Abstract

The present invention relates to a cell assembly including a cell stack in which a plurality of cells having protruding electrode leads are stacked, and heat transfer prevention pads having heat transfer resistance and provided on both sides of the cell stack, and a battery pack including the cell assembly.

Description

[Technical Field]

[0001] The present invention relates to a cell assembly and a battery pack including the same, and more particularly to a cell assembly having thermal safety and a battery pack including the same.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0120778 filed on September 12, 2023 and Korean Patent Application No. 10-2024-0014106 filed on January 30, 2024, and all contents disclosed in the documents of these Korean patent applications are incorporated herein by reference. [Background technology]

[0003] The operating voltage of one cell included in a secondary battery is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, a battery pack may be configured by connecting a plurality of cells in series. Alternatively, a battery pack may be configured by connecting a number of cells in parallel depending on the charge / discharge capacity required for the battery pack. Therefore, the number of cells included in the battery pack may be variously set depending on the required output voltage or charge / discharge capacity.

[0004] When constructing a battery pack by connecting multiple cells in series / parallel, it is common to first construct a cell assembly including at least two or more cells, and then add this cell assembly and other components to construct the battery pack.

[0005] The battery pack has a box-shaped metal housing structure in which a plurality of cell assemblies are housed so as to be in close contact with each other, i.e., each cell assembly is arranged in the battery pack in a state of maximum close contact to eliminate wasted space.

[0006] However, the above structure has a problem in that it is highly vulnerable to the situation when one of the cell assemblies catches fire. That is, if one cell assembly experiences thermal runaway and generates high temperature heat, the high temperature heat can be instantly transferred to other adjacent cell assemblies, which can ultimately lead to a dangerous situation in which the entire cell assembly housed inside the battery pack explodes.

[0007] When the battery pack is applied to an electric vehicle, it is necessary to delay the heat transfer as much as possible from the time when the abnormal phenomenon first occurs until an explosion occurs, thereby giving the driver time to evacuate.

[0008] Therefore, conventionally, research has been conducted into methods for maximally delaying the time it takes for heat to transfer from one cell assembly in which thermal runaway occurs to another cell assembly. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Korean Patent Publication No. 10-2021-0041950 Summary of the Invention [Problem to be solved by the invention]

[0010] Therefore, the present invention has been devised to solve the above problems, and an object of the present invention is to provide a cell assembly having a structure that can minimize the dissipation of heat when high temperature heat is generated in a plurality of stacked cells due to an abnormal phenomenon.

[0011] Another object of the present invention is to provide a battery pack having a structure capable of retarding heat transfer between a plurality of cell assemblies housed therein.

[0012] Other objects and advantages of the present invention can be understood from the following description and become more apparent from the embodiments of the present invention. Also, it is easily understood that the objects and advantages of the present invention can be realized by the means and combinations thereof as set forth in the claims. [Means for solving the problem]

[0013] According to the present invention, there is provided a cell assembly comprising: a cell stack in which a plurality of cells, each having an electrode lead protruding therefrom, are stacked; a bus bar frame including a bus bar electrically connected to the electrode lead of each cell and coupled to at least one of a front surface and a rear surface of the cell stack; and heat transfer prevention pads having heat transfer resistance and provided on both sides of the cell stack.

[0014] The heat transfer prevention pad may include a heat absorption pad that contains a phase change material and absorbs external heat, and a heat insulation pad that has high heat resistance.

[0015] The heat transfer prevention pad is provided such that one of the heat absorbing pad and the heat insulating pad is attached to one surface of the outermost cell stacked in the cell stack.

[0016] The solar cell module may further include a pair of support members provided on both sides of the cell stack and coupled to sides of the bus bar frame to support the plurality of cells, and the heat transfer prevention pad may be interposed between the cell stack and the support members.

[0017] The cell stack may further include a compression pad interposed between any pair of the plurality of cells.

[0018] The present invention also provides a battery pack comprising: the cell assembly of the present invention; and a pack case including a mounting space in which the cell assembly is mounted, the pack case including a base plate supporting a lower portion of the cell assembly; and side beams coupled to edges of the base plate to support sides of the cell assembly.

[0019] A plurality of cell assemblies are mounted in the mounting space, and the pack case may further include a cross beam provided between any pair of adjacent cell assemblies.

[0020] The cross beam may be tightly coupled to the side of the cell assembly so that there is no gap between the cross beam and the cell assembly.

[0021] The sides of the cross beams may be in intimate contact with the heat absorption pads of the opposing cell assemblies.

[0022] The cross beam is connected to each adjacently arranged cell assembly, and the cross beam can be connected to the base plate to fix the cell assemblies to the pack case.

[0023] The heat transfer prevention pad may include a heat absorption pad that contains a phase change material and absorbs external heat, and a heat insulation pad that has high heat resistance.

[0024] The cell assembly may further include a pair of support members provided on both sides of the cell stack and coupled to sides of the bus bar frame to support the plurality of cells, and any pair of adjacent cell assemblies may be fixed to each other by coupling their opposing support members to each other.

[0025] The heat transfer prevention pad may be interposed between the cell stack and the support member.

[0026] The support member may be closely coupled to the heat transfer prevention pad so that there is no gap between the support member and the heat transfer prevention pad. [Effects of the Invention]

[0027] The cell assembly of the present invention and the battery pack of the present invention including the cell assembly have the advantage of improved thermal safety. [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 2 is an exploded perspective view of the cell assembly according to the first embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view showing a state in which an end plate is joined in the cell assembly of FIG. 1. [Figure 3] 2 shows a cross section of the cell assembly of FIG. 1 taken in the width direction of the cell assembly. [Figure 4] FIG. 10 is a perspective view of a cell assembly according to a second embodiment of the present invention. [Figure 5] FIG. 2 is an exploded perspective view showing a state in which a plurality of cell assemblies according to the first embodiment are aligned. [Figure 6] FIG. 2 is a perspective view showing a main part of a pack case in which a plurality of aligned cell assemblies are mounted. [Figure 7] FIG. 7 is a cross-sectional view of a pair of cell assemblies with one of the cross beams interposed therebetween in the battery pack of FIG. 6. [Figure 8] FIG. 10 is a perspective view showing a pack case in which a plurality of cell assemblies according to a second embodiment are mounted. [Figure 9] 9 is a cross-sectional view showing a pair of cell assemblies in intimate contact with each other in the battery pack of FIG. 8. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0029] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. From here on, the terms and words used in the specification and claims are not to be construed as being limited to their ordinary or dictionary meanings, but are to be construed as meanings and concepts that are consistent with the technical idea of ​​the present invention, based on the principle that the inventor can appropriately define the concepts of the terms in order to best describe his / her invention.

[0030] Therefore, the embodiments described in this specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and there may be various equivalents and modifications that can replace them at the time of this application.

[0031] Furthermore, in the description of the present invention, if it is determined that a specific description of related publicly known configurations or functions may obscure the gist of the present invention, the detailed description will be omitted.

[0032] The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art, and therefore the shapes and sizes of components in the drawings may be exaggerated, omitted, or shown schematically for clearer explanation. Therefore, the sizes and proportions of each component do not completely reflect the actual sizes and proportions.

[0033] The present invention relates to a cell assembly and a battery pack including the same, and the battery pack of the present invention is characterized by minimizing heat transfer between each of the housed cell assemblies, thereby improving thermal safety.

[0034] Figures 1 to 3 relate to a cell assembly according to a first embodiment of the present invention, Figure 4 relates to a cell assembly according to a second embodiment of the present invention, Figures 5 to 7 relate to a battery pack including a cell assembly according to the first embodiment of the present invention, and Figures 8 and 9 relate to a battery pack including a cell assembly according to the second embodiment of the present invention.

[0035] Hereinafter, specific embodiments of the cell assembly and battery pack of the present invention will be described in detail with reference to the accompanying drawings. For reference, the directions of front and back, up and down, left and right, and the like used in the following description to specify relative positions are intended to aid in understanding the invention, and unless otherwise specified, are based on the directions shown in the drawings.

[0036] Here, the width direction of the cell assembly refers to the direction in which the cells are stacked, and the longitudinal direction of the cell assembly is defined as the direction perpendicular to the width direction of the cell assembly, i.e., the direction connecting both sides where the bus bar frames or end plates are joined.

[0037] Furthermore, the width direction of the battery pack refers to the longitudinal direction of the cell assembly housed in the battery pack, and the longitudinal direction of the battery pack refers to the width direction of the cell assembly housed in the battery pack.

[0038] Cell assembly 100 The cell assembly 100 of the present invention includes a cell stack 110 containing a plurality of cells 111 .

[0039] The cell 111 includes an electrode assembly in which electrodes including anodes and cathodes and separators are alternately stacked, electrode leads electrically connected to the electrodes, and a battery case that surrounds and seals the electrode assembly so that the electrode leads protrude to the outside.

[0040] The cells 111 can be classified into prismatic cells 111 and pouch cells 111 depending on the shape of the electrode assembly and the battery case.

[0041] The prismatic cell 111 may be in a stack form in which the assembly is stacked by alternately stacking electrodes and separators, or in a stack-fold form in which electrodes and the like are provided on a sheet-like separator that is folded at regular intervals.

[0042] The electrode assembly of the prismatic cell 111 is inserted into a square box-shaped battery case.

[0043] The pouch-type cell 111 may have an electrode assembly in a stacked form or a stack-folded form.

[0044] The pouch-type cell 111 has an electrode assembly inserted into a pouch-shaped battery case, and therefore the cell assembly 100 may include any one of a cylindrical cell 111, a prismatic cell 111, and a pouch-type cell 111.

[0045] The cell assembly 100 includes a plurality of cells 111 and a bus bar frame 120 including bus bars 121 electrically connected to electrode leads included in each of the cells 111 .

[0046] The cell assembly 100 may further include a module frame surrounding the cell stack 110 so that each cell 111 can be protected from external impact. In this case, the module frame may be provided to support or protect only a portion of the cell stack 110, or may be provided on all exposed portions of the cell stack 110 to completely isolate the cell stack 110 from the outside.

[0047] However, in the embodiment of the present invention, in order to make the internal structure easier to understand, the cell assembly 100 to which the above-mentioned module frame configuration is not applied will be mainly described.

[0048] (First embodiment) FIG. 1 is an exploded perspective view of a cell assembly 100 according to a first embodiment of the present invention.

[0049] The cell assembly 100 of the present invention includes a cell stack 110 and a bus bar frame 120, as shown in FIG.

[0050] The cell stack 110 has a configuration in which a plurality of cells 111 are stacked in one direction.

[0051] Each cell 111 includes an electrode assembly in which electrodes and separators are alternately stacked, electrode leads connected to the electrodes, a case surrounding the electrode assembly such that the electrode leads protrude to the outside, and an electrolyte filled in the case together with the electrode assembly.

[0052] The electrode may be a positive electrode in which a slurry containing a positive electrode active material, a binder resin, a conductive material, and other additives is coated on at least one surface of a current collector, or a negative electrode in which a slurry containing a negative electrode active material, a binder resin, a conductive material, and other additives is coated on at least one surface of a current collector. Thus, the electrode assembly is formed by alternately stacking a positive electrode, a separator, and a negative electrode.

[0053] The positive electrode active material may include a lithium-containing transition metal oxide, and the negative electrode active material may include lithium metal, a carbon material, a metal compound, or a mixture thereof capable of absorbing and releasing lithium ions.

[0054] The separator may be a typical porous polymer film used in lithium secondary batteries.

[0055] The case is made of a sheet material processed into a predetermined shape. The sheet material has a multilayer structure including an outermost resin layer made of an insulating material such as polyethylene terephthalate (PET) or Nylon®, an aluminum metal layer that maintains mechanical strength and prevents moisture and oxygen from penetrating, and an inner resin layer made of a polyolefin-based material that has thermal adhesive properties and acts as a sealant.

[0056] The sheet material constituting the case may have a predetermined adhesive resin layer interposed between the inner resin layer and the metal layer, and between the outer resin layer and the metal layer, as required. The adhesive resin layer is for smooth adhesion between different materials and may be formed as a single layer or multiple layers. The material may typically be a polyolefin resin, or a polyurethane resin for smooth processing, or a mixture thereof may also be used.

[0057] The cell 111 may be classified into a square type, a pouch type, and a cylindrical type depending on the shape of the electrode assembly and the case, but for ease of understanding, the detailed description and drawings of the present invention will be described using a pouch type cell 111 as an example.

[0058] The bus bar frame 120 includes bus bars 121 that are coupled to and electrically connected with electrode leads of the cell stack 110 , and is coupled to at least one of the front and rear surfaces of the cell stack 110 .

[0059] The bus bar frame 120 not only presses and aligns the cells 111 included in the cell stack 110, but also bundles the electrode leads protruding from the cells 111. Specifically, a conductive bus bar 121 is fixed on the bus bar frame 120, and a plurality of electrode leads drawn from the cell stack 110 are connected to the bus bar frame 120. At this time, the electrode leads and the bus bar frame 120 may be connected typically by welding, but any other connection method capable of electrically connecting the electrode leads and the bus bar frame 120 may also be used.

[0060] The cell assembly 100 may further include an end plate 130 covering the bus bar frame 120 .

[0061] FIG. 2 is a perspective view showing a state in which an end plate 130 is joined to the cell assembly 100 of FIG.

[0062] As shown in FIGS. 1 and 2, the cell assembly 100 may further include end plates 130 provided to cover the bus bar frame 120 to protect the bus bar frame 120 from external impact.

[0063] The cell assembly 100 of the present invention may further include heat transfer prevention pads 140 on both sides of the cell stack 110, each pad having heat transfer resistance.

[0064] FIG. 3 shows a cross section of the cell assembly 100 of FIG. 1 cut in the width direction of the cell assembly 100. As shown in FIG.

[0065] Referring to FIG. 3, a pair of heat transfer prevention pads 140 are provided on both sides of the cell stack 110, respectively.

[0066] The heat transfer prevention pad 140 includes a heat absorbing pad 141 and a heat insulating pad 142. That is, the heat transfer prevention pad 140 includes the heat absorbing pad 141 and the heat insulating pad 142 that are joined to each other.

[0067] Specifically, the heat absorbing pad 141 contains a phase change material and absorbs heat from a material that comes into contact with it.

[0068] The heat absorbing pad 141 includes a heat absorbing material that is in one of a solid and a liquid state, and the heat absorbing material changes phase by absorbing heat from a material that comes into contact with the heat absorbing pad 141. Therefore, the heat absorbing pad 141 can absorb a certain portion of the heat from the material that comes into contact with the pad 141.

[0069] The heat insulating pad 142 is characterized by high heat resistance.

[0070] Specifically, the insulating pad 142 includes an insulating material with low thermal conductivity, which prevents heat transfer through the insulating pad 142 .

[0071] In some embodiments, the heat absorption pad 141 is provided facing one side of the cell 111 stacked at the outermost periphery of the cell stack 110, as shown in FIG. 3, and the heat insulation pad 142 is interposed between the heat absorption pad 141 and the cell stack 110.

[0072] In another embodiment, although not shown, the heat insulating pad 142 is provided facing one side of the cell 111 stacked at the outermost periphery of the cell stack 110, and the heat absorbing pad 141 is interposed between the heat insulating pad 142 and the cell stack 110.

[0073] That is, the heat transfer prevention pad 140 is provided such that one of the heat insulating pad 142 and the heat absorbing pad 141 is attached to one surface of the cell stack 110 .

[0074] When high temperature heat is generated in the adjacent cell stack 110, the heat absorbing pad 141 primarily prevents heat transfer via the heat insulating pad 142 adjacent to the cell stack 110. In addition, a portion of the heat conducted via the heat insulating pad 142 is secondarily absorbed by the heat absorbing pad 141.

[0075] The heat absorbing pad 141 is characterized by absorbing external heat.

[0076] The heat transfer prevention pad 140 of the present invention, which includes the heat absorption pad 141 and the heat insulation pad 142, absorbs heat when a material in contact with it emits heat, and simultaneously minimizes the transmission of heat.

[0077] In some embodiments, the cell stack 110 may further include a compression pad 160 interposed between any pair of the cells 111 of the plurality of cells 111 .

[0078] The cell stack 110 may include a plurality of compression pads 160 interposed between the cells 111. In this case, the spacing between the compression pads 160 may be regular as shown in Fig. 3 or irregular. For example, one cell 111 may be located between a pair of compression pads 160, or multiple cells 111 may be located between the pair of compression pads 160.

[0079] The compression pad 160 can at least partially absorb shocks and pressures that may occur between the stacked cells 111 .

[0080] The compression pads 160 are inserted into the cell stack 110 at regular intervals to physically separate the cells 111 .

[0081] (Second embodiment) FIG. 4 is a perspective view of a cell assembly 100 according to a second embodiment of the present invention.

[0082] Referring to FIG. 4, the cell assembly 100 may further include support members 150 for protecting both sides of the exposed cell stack 110 .

[0083] That is, the cell assembly 100 of the present invention may further include a pair of support members 150 provided on both sides of the cell stack 110 to support the plurality of cells 111, as shown in FIG. 4 above.

[0084] The support member 150 serves to protect the cell stack 110 and the heat transfer prevention pads 140 provided on both sides of the cell stack 110 from external impact.

[0085] In addition, when the cell assembly 100 is mounted on a battery pack or the like, the support member 150 serves to provide a location to which a connecting member such as a bolt or screw is directly connected to fix the cell stack 110 to the battery pack.

[0086] The support member 150 can also serve to prevent heat transfer between the cell assembly 100 including the support member 150 and other adjacent cell assemblies 100 .

[0087] In some embodiments, the support member 150 may be coupled to a side of a bus bar frame 120 provided adjacent to the cell stack 110 .

[0088] In some embodiments, the support member 150 may be coupled to a side of an end plate 130 provided on the bus bar frame 120 .

[0089] Battery pack The battery pack of the present invention includes a cell assembly 100 and a pack case 200 in which the cell assembly 100 is mounted. That is, a plurality of the cell assemblies 100 according to the first or second embodiment can be assembled and mounted in one pack case 200 to form a battery pack.

[0090] FIG. 5 is an exploded perspective view showing a state in which a plurality of cell assemblies 100 according to the first embodiment are aligned, and FIG. 6 is a perspective view showing a main part of a pack case 200 in which the aligned plurality of cell assemblies 100 are mounted.

[0091] 5 and 6, the battery pack of the present invention includes the cell assembly 100 of the present invention and a pack case 200 including a mounting space A in which the cell assembly 100 is mounted.

[0092] In some embodiments, the pack case 200 includes a base plate 210 configured to cover and support the bottom of the multiple cell assemblies 100, and side beams 220 configured to cover and support the sides.

[0093] In some embodiments, the pack case 200 may further include cross beams 240 separating the cell assemblies 100 .

[0094] A plurality of cell assemblies 100 can be aligned side by side as shown in FIG. 5, and in this case, a cross beam 240 can be placed between a pair of adjacent cell assemblies 100 in the width direction to physically separate the cell assemblies 100 from each other while supporting the sides of the cell assemblies 100.

[0095] The mounting space A is a space formed by the upper surface of the base plate 210 and the inner surfaces of the side beams 220, and a plurality of cell assemblies 100 are mounted in the mounting space A.

[0096] 6, the pack case 200 may further include a center beam 230 that crosses the center and is coupled to the base plate 210 to define the mounting space A. The center beam 230 divides the mounting space A of the pack case 200 into two spaces, and physically isolates the cell assemblies 100 that are mounted in each space.

[0097] In some embodiments, the cross beam 240 can be assembled to the pack case 200 together with the cell assemblies 100, as shown in Figures 5 and 6. That is, the cross beam 240 can be primarily connected to each adjacently arranged cell assembly 100, and the cross beam 240 can be connected to the base plate 210 to fix the cell assembly 100 to the pack case 200.

[0098] In some embodiments, the cross beam 240 may be coupled to the center beam 230 and the side beams 220 separately from the cell assembly 100. That is, the cross beam 240 interposed between the cell assemblies 100 may be coupled to the base plate 210, or may be coupled to the center beam 230 and the side beams 220. Specifically, both ends of the cross beam 240 may be coupled to the side of the center beam 230 and the inner surface of the side beam 220, respectively.

[0099] Therefore, the plurality of cell assemblies 100 can be separately mounted in the spaces formed by the partitions of the side beams 220, the center beam 230, and the cross beams 240, respectively.

[0100] In some embodiments, the cross beam 240 can prevent each cell assembly 100 from shaking or being damaged by an external impact. Therefore, as shown in FIG. 6 , the cross beam 240 can be tightly coupled to the side of the cell stack 110 so that there is no gap between the cross beam 240 and the cell assembly 100.

[0101] Fig. 7 is a cross-sectional view of a pair of cell assemblies 100 with one of the cross beams 240 interposed therebetween in the battery pack of Fig. 6. More specifically, Fig. 7 shows a cross section of the pair of cell assemblies 100 cut in the width direction of the cell assemblies 100, and is an embodiment in which a heat insulating pad 142 is interposed between a heat absorbing pad 141 and a cell stack 110.

[0102] 7, the cross beam 240 is in contact with the heat absorbing pad 141 of the cell assembly 100 facing it. That is, high temperature heat transferred from one cell assembly 100 can be first transferred to the heat absorbing pad 141 included in another cell assembly 100 via the cross beam 240. The heat absorbing pad 141 primarily absorbs the heat transferred from the cross beam 240, and the heat insulating pad 142 adjacent to the heat absorbing pad 141 maximally prevents the transfer of excess heat not absorbed by the heat absorbing pad 141.

[0103] Although not shown, in an embodiment in which a heat absorption pad 141 is interposed between the heat insulation pad 142 and the cell stack 110, the heat insulation pad 142 first blocks heat conducted from the cross beam 240. Then, the heat absorption pad 141 adjacent to the heat insulation pad 142 absorbs excess heat passing through the heat insulation pad 142.

[0104] The heat transfer prevention pad 140 of the present invention can reduce heat transfer in the above two ways.

[0105] In a conventional battery pack, a pair of cell assemblies 100 are positioned very close to each other with a cross beam 240 between them, so if one of the cell assemblies 100 experiences thermal runaway, the high temperature heat generated in the experiencing cell assembly 100 can be transferred to the other cell assembly 100 via the adjacent cross beam 240. In contrast, in the battery pack of the present invention, the heat transfer prevention pad 140 provided in each cell assembly 100 can suppress the heat transfer to some extent.

[0106] FIG. 8 is an oblique view showing a pack case 200 in which multiple cell assemblies 100 according to the second embodiment are mounted, and FIG. 9 is a cross-sectional view showing a pair of cell assemblies 100 in close contact in the battery pack of FIG. 8.

[0107] The pack case 200 of FIG. 8 includes the cell assembly 100 according to the second embodiment shown in FIG.

[0108] The cell assembly 100 further includes a pair of support members 150 provided on both sides of the cell stack 110 and coupled to the sides of the bus bar frame 120 to support the plurality of cells 111 .

[0109] Therefore, any pair of adjacently arranged cell assemblies 100 can be fixed by connecting the opposing support members 150. In this case, two adjacent support members 150 can be fixed to each other by being screwed together using connecting members such as bolts.

[0110] In the battery pack including the cell assemblies 100 and pack case 200 shown in Figure 8 above, each cell assembly 100 includes support members 150 on both sides. Therefore, unlike the battery packs shown in Figures 5 and 6 above, two support members 150 are interposed between a pair of adjacently arranged cell stacks 110.

[0111] In some embodiments, the support members 150 not only improve the support force of the cell stack 110 but also serve to prevent heat transfer between the cell assemblies 100 .

[0112] 9, two support members 150 are interposed between a pair of cell stacks 110. In this case, if one of the cell stacks 110 experiences thermal runaway, the high temperature heat generated in the thermally runaway cell stack 110 passes through the heat insulating pad 142, the heat absorbing pad 141, and the support member 150 in that order, and is absorbed or blocked as it moves successively through the support member 150, the heat absorbing pad 141, and the heat insulating pad 142 of the other cell assembly 100 in that order.

[0113] Although not shown, the battery pack of the present invention further includes an upper case coupled to the pack case 200 to cover the upper portion of the cell assembly 100 seated in the pack case 200 .

[0114] Specifically, the upper case is coupled to the side beams 220 of the pack case 200, so that each cell assembly 100 positioned in the internal space can be isolated from the outside.

[0115] The present invention has been described in more detail above with reference to the drawings and embodiments, etc. However, the configurations shown in the drawings or embodiments in this specification are merely one embodiment of the present invention and do not represent all of the technical ideas of the present invention, and therefore, at the time of filing this application, there may be various equivalents and modifications that can replace them. [Explanation of symbols]

[0116] 100: Cell assembly 110: Cell stack 111: Cell 120: Busbar frame 121: Busbar 130: End plate 140: Heat transfer prevention pad 141: Heat absorption pad 142: Heat insulation pad 150: Support member 160: Compression pad 200: Pack case 210: Base plate 220: Side beam 230: Center beam 240: Cross beam A: Safety space

Claims

1. a cell stack in which a plurality of cells having protruding electrode leads are stacked; and heat transfer prevention pads having heat transfer resistance and provided on both sides of the cell stack.

2. 2. The cell assembly according to claim 1, wherein the heat transfer prevention pad comprises a heat absorption pad containing a phase change material and absorbing external heat, and a heat insulation pad having high heat resistance.

3. The cell assembly of claim 2 , wherein the heat transfer prevention pad is provided such that one of the heat absorption pad and the heat insulation pad is attached to one surface of the outermost cell of the cell stack.

4. a pair of support members provided on opposite sides of the cell stack to support the plurality of cells; The cell assembly of claim 1 , wherein the heat transfer prevention pad is interposed between the cell stack and the support member.

5. The cell assembly according to claim 1 , wherein the cell stack further includes a compression pad interposed between any pair of the plurality of cells.

6. A cell assembly according to any one of claims 1 to 5; a pack case including a mounting space in which the cell assembly is mounted, The pack case is a base plate supporting a lower portion of the cell assembly; side beams coupled to edges of the base plate to support sides of the cell assemblies.

7. A plurality of cell assemblies are mounted in the mounting space, The battery pack according to claim 6 , wherein the pack case further includes a cross beam provided between any pair of adjacent cell assemblies.

8. The battery pack according to claim 7 , wherein the cross beam is tightly coupled to a side of the cell assembly such that there is no gap between the cross beam and the cell assembly.

9. 8. The battery pack of claim 7, wherein a side of the cross beam is in intimate contact with a heat absorption pad of the cell assembly opposite it.

10. 8. The battery pack according to claim 7, wherein the cross beam is coupled to each adjacently arranged cell assembly, and the cross beam is coupled to the base plate to fix the cell assembly to the pack case.

11. 7. The battery pack according to claim 6, wherein the heat transfer prevention pad includes a heat absorption pad containing a phase change material and absorbing external heat, and a heat insulation pad having high heat resistance.

12. the cell assembly further includes a pair of support members provided on opposite sides of the cell stack and coupled to support the plurality of cells; 7. The battery pack according to claim 6, wherein any pair of adjacently arranged cell assemblies are fixed by joining the support members positioned opposite each other.

13. The battery pack according to claim 12 , wherein the heat transfer prevention pad is interposed between the cell stack and the support member.

14. The battery pack of claim 12 , wherein the support member is closely coupled to the heat transfer prevention pad so that there is no gap between the support member and the heat transfer prevention pad.

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