Thermal barrier pads, battery packs, and battery modules

Abstract

A thermal barrier pad is provided, comprising: a porous heat-insulating absorbent having a first main surface and a second main surface; an endothermic solution composition absorbed by the heat-insulating absorbent; a heat-conducting sheet covering at least one of the first and second main surfaces of the heat-insulating absorbent; and a heat-dissipating pouch surrounding the heat-insulating absorbent and the heat-conducting sheet, the endothermic solution composition comprising about 0.20% to about 0.45% by weight of a surfactant, about 0.3% to about 5.0% by weight of a thickener, and about 60% to about 80% by weight of water.

Description

Technical Field

[0001] The present invention relates to a thermal barrier pad, a battery pack, and a battery module, and more specifically, to a thermal barrier pad capable of effectively blocking or delaying the transfer of heat generated by a battery cell to other adjacent battery cells, and a battery pack and a battery module including the same.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0062086 filed on May 10, 2024 and Korean Patent Application No. 10-2025-0003705 filed on January 9, 2025, and all the contents disclosed in the documents of the Korean patent applications are included as part of this specification.

Background Art

[0003] A secondary battery means a battery that can be charged and discharged, unlike a primary battery that cannot be recharged, and is widely used in electronic devices such as mobile phones, notebook computers, camcorders, or electric vehicles. In particular, lithium secondary batteries have a larger capacity than nickel-cadmium batteries or nickel-metal hydride batteries and a high energy density per unit weight, so the degree of their utilization tends to increase at a rapid pace.

[0004] Various structures and / or manufacturing methods have been proposed and applied for manufacturing secondary batteries, and various means have been taken to improve the quality of secondary batteries.

Summary of the Invention

Problems to be Solved by the Invention

[0005] The first technical problem to be achieved by the present invention is to provide a thermal barrier pad capable of effectively blocking or delaying the transfer of heat generated by a battery cell to other adjacent battery cells.

[0006] A second technical problem that the present invention aims to solve is to provide a battery pack that includes a thermal barrier pad that can effectively block or delay the transfer of heat generated in one battery cell to other adjacent battery cells.

[0007] A third technical problem that the present invention aims to solve is to provide a battery module that includes a thermal barrier pad that can effectively block or delay the transfer of heat generated in one battery cell to other adjacent battery cells. [Means for solving the problem]

[0008] To achieve the above first technical objective, the present invention provides a thermal barrier pad comprising: a porous heat-insulating absorbent having a first main surface and a second main surface; a heat-absorbing solution composition absorbed by the heat-insulating absorbent; a heat-conducting sheet covering at least one of the first and second main surfaces of the heat-insulating absorbent; and a heat-dissipating pouch surrounding the heat-insulating absorbent and the heat-conducting sheet, and including a metal layer, wherein the heat-absorbing solution composition comprises about 0.20% to about 0.45% by weight of a surfactant, about 0.3% to about 5.0% by weight of a thickener, and about 60% to about 80% by weight of water.

[0009] In some embodiments, the thickener may include carboxymethyl cellulose (CMC), carboxyethyl cellulose, polyvinyl alcohol (PVA), starch, polyethylene oxide (PEO), hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, or glucomannan.

[0010] In some embodiments, the above-mentioned endothermic solution composition may contain about 15% to about 35% by weight of an antifreeze agent.

[0011] In some embodiments, the antifreeze may include CaCl2, NaCl, potassium acetate, potassium formate, isopropanol, butyl diglycol, ethylene glycol, diethylene glycol, dipropylene glycol, propylene glycol, urea, and / or glycerol.

[0012] In some embodiments, the endothermic solution composition may contain about 20% to about 30% by weight of an antifreeze agent.

[0013] In some embodiments, the endothermic solution composition may contain about 23% to about 27% by weight of an antifreeze agent.

[0014] In some embodiments, the above-mentioned endothermic solution composition may contain about 0.5% to about 3% by weight of a thickening agent.

[0015] In some embodiments, the endothermic solution composition may contain about 1% to about 2.2% by weight of a thickening agent.

[0016] In some embodiments, the surfactant may be a silicon (Si)-based surfactant.

[0017] In some embodiments, the surfactant may include polydimethylsiloxane (PDMS).

[0018] In some embodiments, the thermal conductive sheet may include copper, aluminum, zinc, tin, iron, or alloys thereof.

[0019] In some embodiments, the thermal conductive sheet is a copper sheet or a copper alloy sheet and can have a thickness of about 5 μm to about 50 μm.

[0020] In some embodiments, the heat-insulating absorbent material may include a non-woven fabric mainly composed of silica fibers.

[0021] In order to achieve the above-mentioned second technical problem, the present invention provides a battery pack including a pack case, a plurality of secondary batteries housed in the pack case and stacked in a first direction, and the thermal barrier pads provided between the plurality of secondary batteries.

[0022] In order to achieve the above-mentioned third technical problem, the present invention provides a battery module including a module case, a plurality of secondary batteries housed in the module case and stacked in a first direction, and the thermal barrier pads provided between the plurality of secondary batteries.

Advantages of the Invention

[0023] The thermal barrier pad of the present invention can effectively block or delay the heat generated by the stacked battery cells from being transmitted to other adjacent battery cells.

[0024] The effects obtained from the exemplary embodiments of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those having ordinary knowledge in the technical field to which the exemplary embodiments of the present disclosure belong from the following description. That is, the unintended effects associated with implementing the exemplary embodiments of the present disclosure can also be derived by those having ordinary knowledge in the technical field from the exemplary embodiments of the present disclosure.

Brief Description of the Drawings

[0025] [Figure 1] It is a perspective view of a battery pack according to an exemplary embodiment of the present invention. [Figure 2] It is a perspective view showing some elements of a battery pack according to an exemplary embodiment of the present invention. [Figure 3] It is an enlarged perspective view showing a state where battery cells are mounted in a lower case according to an embodiment of the present invention. [Figure 4] It is an exploded perspective view showing a thermal barrier pad according to an embodiment of the present invention. [Figure 5]This is a perspective view of a thermal barrier pad according to one embodiment of the present invention. [Figure 6] This is a schematic side cross-sectional view showing the thermal barrier pad inserted between the battery cells. [Figure 7] Figure 5 is a front view of a thermal barrier pad according to one embodiment of the present invention. [Figure 8] This is a cross-sectional view showing the thermal barrier pad cut along the line VIII-VIII' in Figure 7. [Figure 9] This graph shows the temperature change over time measured for the thermal barrier pads of Comparative Example 1 and Examples 1 to 4, respectively. [Figure 10] This is a perspective view of a battery pack according to another embodiment of the present invention. [Figure 11] This is a disassembled perspective view of a battery module according to one embodiment of the present invention. [Figure 12] This is a perspective view of a battery module according to one embodiment of the present invention. [Figure 13] This is a schematic side view showing an electric vehicle according to one embodiment of the present invention. [Figure 14] This is a schematic diagram conceptually showing the battery pack and other components installed in the above-mentioned electric vehicle. [Modes for carrying out the invention]

[0026] Preferred embodiments of the concept of the present invention will be described in detail below with reference to the accompanying drawings. However, embodiments of the concept of the present invention can be modified into various different forms, and the scope of the concept of the present invention should not be construed as being limited by the embodiments described below. It is preferable that embodiments of the concept of the present invention be construed as being provided to more fully explain the concept of the present invention to a person of average knowledge in the art. The same reference numerals mean the same element throughout. Furthermore, various elements and areas in the drawings are depicted schematically. Therefore, the concept of the present invention is not limited by the relative sizes or spacings depicted in the accompanying drawings.

[0027] Terms such as "first," "second," etc., can be used to describe various components, but such components are not limited by these terms. These terms are used solely for the purpose of distinguishing one component from another. For example, without departing from the scope of the concept of the present invention, the first component may be named the second component, and conversely, the second component may be named the first component.

[0028] The terms used in this application are used solely to describe specific embodiments and are not intended to limit the concepts of the invention. A singular expression includes plural expressions unless the context clearly indicates otherwise. In this application, expressions such as “includes” or “has” are intended to specify the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and are understood not to preemptively exclude the presence or possibility of adding one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0029] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as those commonly understood by those of ordinary skill in the art to which the concepts of this invention pertain. Furthermore, terms defined in commonly used dictionaries may be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an overly formal sense unless explicitly defined herein.

[0030] Where a particular embodiment can be otherwise realized, a specific sequence of steps may be performed in a different order than that described. For example, two steps described consecutively may be performed substantially simultaneously, or in the reverse order of the description.

[0031] In the accompanying drawings, deformations of the shown shapes can be expected, for example, due to manufacturing techniques and / or tolerances. Therefore, embodiments of the present invention should not be construed as being limited to specific shapes of the regions shown herein, and may include, for example, changes in shape resulting from the manufacturing process. All terms used herein, "and / or," include each of the components mentioned and all combinations of one or more of them.

[0032] Figure 1 is a perspective view of a battery pack 100 according to an exemplary embodiment of the present invention.

[0033] Figure 2 is a perspective view showing some elements of a battery pack 100 according to an exemplary embodiment of the present invention.

[0034] In Figures 1 and 2, the battery pack 100 is shown as being defined in a vertical coordinate system defined as a first direction along the X-axis, a second direction along the Y-axis, and a third direction along the Z-axis, all of which are perpendicular to each other. However, the first, second, and third directions only need to be perpendicular to each other and are not particularly limited.

[0035] Referring to Figures 1 and 2, the battery pack 100 may include a lower case 110, battery cells 120, a center beam 130, a cross beam 116, multiple exhaust devices 140, multiple first embedding guides 151, multiple second embedding guides 153, a pack gasket 160, and an upper case 170. The battery pack 100 may be the final form of a battery system installed in a mobility device or the like.

[0036] The pack housing 101 defining the appearance of the battery pack 110 may include the lower case 110 and the upper case 170.

[0037] The lower case 110 can provide a housing space 119 for mounting multiple battery cells 120. In some embodiments, the lower case 110 may include a plate portion 110P and a side wall 110S. Two directions substantially parallel to the plate portion 110P are defined as the first direction (e.g., the X-axis direction) and the second direction (e.g., the Y-axis direction), and a direction substantially perpendicular to the plate portion 110P of the housing 110 is defined as the third direction (e.g., the Z-axis direction). The X-axis, Y-axis, and Z-axis directions may each be substantially perpendicular to one another. Unless otherwise noted, the definitions of directions are the same for the following drawings.

[0038] Multiple battery cells 120 can be arranged on the plate portion 110P of the lower case 110. The plate portion 110P can support the multiple battery cells 120. The plate portion 110P may include substantially parallel upper and lower surfaces. The upper surface of the plate portion 110P can face the multiple battery cells 120. The lower surface of the plate portion 110P is the opposite surface of the upper surface of the plate portion 110P.

[0039] The side wall 110S can horizontally enclose multiple battery cells 120. The side wall 110S can laterally protect multiple battery cells 120. The side wall 110S may include a first side wall 111, a second side wall 112, a third side wall 113, and a fourth side wall 114. The first to fourth side walls 111, 112, 113, and 114 can be fixed to each other by methods such as friction stir welding or spot welding, and are not particularly limited.

[0040] The first side wall 111 and the second side wall 112 may be substantially perpendicular to the second direction (e.g., the Y-axis direction). The third side wall 113 and the fourth side wall 114 may each be substantially perpendicular to the first direction (e.g., the X-axis direction). In some embodiments, the first side wall 111 and the second side wall 112 may cover the sides of the plate portion 110P. In some embodiments, the third side wall 113 and the fourth side wall 114 may be positioned on the plate portion 110P.

[0041] In some embodiments, the first to fourth side walls 111, 112, 113, and 114 can be provided by an extrusion process. According to exemplary embodiments, the first to fourth side walls 111, 112, 113, and 114 may include internal empty spaces, thereby reducing the weight of the side wall 110S. According to exemplary embodiments, the empty spaces in the first to fourth side walls 111, 112, 113, and 114 may be either gas venting paths or coolant channels.

[0042] The technical idea of ​​the present invention will be described below with reference to embodiments in which each of the multiple battery cells 120 does not include a module frame. However, this is an example that is not limiting in any sense to the technical idea of ​​the present invention. A person of ordinary skill in the art can also easily arrive at a battery pack in which a battery module including a module frame that exposes one side edge of the battery cell is employed based on what is described herein.

[0043] The above-mentioned accommodation space 119 can be divided into two or more partitioned spaces 119d by one or more partition beams 130, 116. The partition beams 130, 116 may include a center beam 130. In some embodiments, the partition beams 130, 116 may include one or more cross beams 116.

[0044] The center beam 130 can isolate the elements mounted on the lower case 110 from each other. This allows the center beam 130 to protect the multiple battery cells 120 and prevent undesirable short circuits between them.

[0045] The center beam 130 can extend between the third side wall 113 and the fourth side wall 114. The center beam 130 can extend in a first direction (e.g., the X-axis direction). The center beam 130 can be in contact with the third side wall 113 and the fourth side wall 114. The center beam 130 can isolate a plurality of battery cells 120 from each other. The center beam 130 can be interposed between a plurality of battery cells 120. In some embodiments, the center beam 130 can divide the accommodation space 119 into two regions in a second direction (e.g., the Y-axis direction).

[0046] In some embodiments, the crossbeam 116 can be provided to divide the accommodation space 119 into two or more regions in a first direction (e.g., the X-axis direction). The crossbeam 116 can further isolate elements isolated by the center beam 130.

[0047] Some crossbeams 116 may extend in a second direction (e.g., the Y-axis direction) between the center beam 130 and the first side wall 111. Other crossbeams 116 may extend in a second direction (e.g., the Y-axis direction) between the center beam 130 and the second side wall 112. In some embodiments, the crossbeams 116 may be provided to define a space in which a single battery cell stack or a group of battery cells are housed.

[0048] The arrangement of the center beam 130, cross beam 116, and multiple battery cells 120 disclosed in Figure 1 is a non-limiting example and does not limit the technical idea of ​​the present invention in any sense. A person of ordinary skill in the art can readily arrive at battery packs including a variety of arrangements and numbers of center beams and battery cells based on what is described herein.

[0049] Multiple exhaust devices 140 can be coupled to the fourth side wall 114. The fourth side wall 114 may include multiple exhaust holes connected to the multiple exhaust devices 140. The multiple exhaust holes may be configured to provide a path for exhausting gases and heat from inside the battery pack 100.

[0050] Multiple exhaust devices 140 can be configured to delay thermal propagation by releasing high-temperature gas from inside the battery pack 100 to the outside when at least one of the multiple battery cells 120 is in a thermal runway state.

[0051] Here, thermal runaway of multiple battery cells 120 is a state in which the temperature change of multiple battery cells 120 further accelerates that temperature change, resulting in an uncontrollable positive feedback loop. Multiple battery cells 120 in a thermal runaway state exhibit a rapid temperature increase and can emit large amounts of high-pressure gas and combustion residue.

[0052] In some embodiments, multiple first embedding guides 151 can be positioned on a side wall 110S. Multiple first embedding guides 151 can be positioned on the corners 110C of the upper surface of the side wall 110S. Multiple first embedding guides 151 can be coupled to the corners 110C of the upper surface of the side wall 110S. Multiple first embedding guides 151 can be partially embedded in the side wall 110S. Multiple first embedding guides 151 can partially protrude from the side wall 110S.

[0053] In some embodiments, multiple second embedding guides 153 can be positioned on the side wall 110S. Multiple second embedding guides 153 can be positioned on the upper surface of the side wall 110S. Multiple second embedding guides 153 can be interposed between the corners 110C of the side wall 110S. Multiple second embedding guides 153 can be interposed between multiple first embedding guides 151. Multiple second embedding guides 153 can be coupled to the upper surface of the side wall 110S. Multiple second embedding guides 153 can be partially embedded in the side wall 110S. Multiple second embedding guides 153 can partially protrude from the side wall 110S.

[0054] In some embodiments, each of the plurality of first embedding guides 151 and second embedding guides 153 may include a metallic material. Each of the plurality of first embedding guides 151 and second embedding guides 153 may include, for example, aluminum. Each of the plurality of first embedding guides 151 and second embedding guides 153 may include, for example, steel such as carbon steel, nickel steel, chromium steel, nickel-chromium steel, and manganese steel.

[0055] The battery pack 100 may further include electrical components. In some embodiments, these electrical components may be mounted on the lower case 110. In some embodiments, these electrical components may be located between the fourth side wall 114, where the exhaust device 140 is installed, and the plurality of battery cells 120. In some embodiments, the electrical components may include any electronic elements necessary to power the battery pack.

[0056] In some embodiments, the electrical components may include, for example, a battery management system (BMS). The BMS may be configured to monitor, balance, and control the battery pack. In some embodiments, monitoring of the battery pack 100 may include measuring the voltage and current of a specific battery cell among a plurality of battery cells 120, and measuring the temperature at a set location inside the battery pack 100. In some embodiments, the battery pack 100 may include measuring instruments for measuring the voltage, current, and temperature mentioned above.

[0057] Balancing the battery pack 100 is an operation to reduce deviations between multiple battery cells 120. Control of the battery pack 100 includes preventing overcharging, over-discharging, and overcurrent. Through monitoring, balancing, and control, the battery pack 100 can operate under optimal conditions, thereby preventing or reducing shortening of the lifespan of each of the multiple battery cells 120.

[0058] The above electrical components may further include a cooling system, a power relay assembly (PRA), a safety plug, and the like. The cooling system may include a cooling fan. The cooling fan can prevent each of the multiple battery cells 120 from overheating by circulating air inside the battery pack 100. The PRA can be configured to supply or cut off power from the high-voltage battery to an external load (e.g., the vehicle's motor). The PRA can protect the multiple battery cells 120 and the external load (e.g., the vehicle's motor) by cutting off the power supply to the external load (e.g., the vehicle's motor) in situations where abnormal voltages occur, such as voltage surges.

[0059] The battery pack 100 may further include a plurality of busbars configured to electrically connect a plurality of battery cells 120. The plurality of battery cells 120 can be connected in series and / or parallel by the plurality of busbars. This allows the battery pack 100 to be configured to output a high voltage to an external load (e.g., a vehicle motor).

[0060] The gasket 160 may include a material that is elastic in response to applied pressure. The gasket 160 may include rubber synthesized from a material such as EPDM (ethylene-propylene diene monomer). When the lower case 110 and the upper case 170 are joined together, the gasket 160 can be interposed between the lower case 110 and the upper case 170. The lower case 110 and the upper case 170 can pressurize the gasket 160 so that it deforms slightly. This allows the battery pack 100 to be sealed and external fluids to be isolated from the internal space of the battery pack 100.

[0061] The upper case 170 can be coupled to the lower case 110 so as to cover the housing space 119. In some embodiments, the upper case 170 may include a main surface and an edge. The main surface may cover elements mounted on the battery pack 100, such as a plurality of battery cells 120 and electrical components. The edge is the surface that contacts the lower case 110. In some embodiments, the upper case 170 may have a flat plate form, in which case the edge may horizontally surround the main surface. In some embodiments, the main surface may be elevated compared to the edge, and the edge and the main surface may be connected by a curved portion.

[0062] In some embodiments, the upper case 170 can be coupled to the side wall 110S of the lower case 110 by a plurality of first embedding guides 151 and second embedding guides 153. According to an exemplary embodiment, the battery pack 100 may further include elements coupled to the plurality of first embedding guides 151 and second embedding guides 153 for securing the upper case 170 to the side wall 110S of the lower case 110. These elements may, but are not limited to, bolts and nuts.

[0063] Figure 3 is an enlarged perspective view showing how a battery cell 120 is installed inside a lower case 110 according to one embodiment of the present invention.

[0064] Referring to Figure 3, battery cell stacks S1, S2, ..., S6 are arranged within the regions defined by the side walls 111, 112, 113, 114 of the lower case 110, the center beam 130, and the cross beam 116. Each of the battery cell stacks S1, S2, ..., S6 contains a plurality of battery cells 120. Hereinafter, a battery cell stack may simply mean a collection of a plurality of battery cells, or it may mean an assembly of a plurality of battery cells housed within a particular frame.

[0065] In some embodiments, the battery cell 120 may be a pouch-type battery cell, but the present invention is not limited thereto. In other embodiments, the battery cell 120 may be a rectangular battery cell or a cylindrical battery cell.

[0066] In some embodiments, the pouch-type battery cell may have an electrode assembly formed by alternately stacking a positive electrode, a separator, and a negative electrode, with an electrode tab extended from at least one side and connected to a cell lead. The positive and negative electrodes can be manufactured by applying a slurry of electrode active material, binder resin, conductive material, and other additives to at least one surface of a current collector. For the positive electrode, a conventional positive electrode active material such as a lithium-containing transition metal oxide can be used, and for the negative electrode, a conventional negative electrode active material such as lithium metal, carbon material, metal compound, or mixture thereof, which can intercept and release lithium ions, can be used. Furthermore, a conventional porous polymer film used in lithium secondary batteries can be used as the separator.

[0067] A standard lithium secondary battery electrolyte can be used as the electrolyte housed within the cover along with the electrode assembly. The cover is made of a sheet material and includes a housing for housing the electrode assembly. Preferably, the cover is formed by joining a first case and a second case, both formed by processing the sheet material into a predetermined shape. The sheet material forming the cover has a multilayer structure in which an outermost resin layer made of an insulating material such as polyethylene terephthalate (PET) or nylon, a metal layer made of aluminum that maintains mechanical strength and prevents the penetration of moisture and oxygen, and an inner resin layer made of a polyolefin-based material that has heat adhesion and acts as a sealing material are laminated together.

[0068] The sheet material forming the cover may, if necessary, have a predetermined adhesive resin layer interposed between the internal resin layer and the metal layer, and between the external resin layer and the metal layer. The adhesive resin layer is for smooth adhesion between dissimilar materials and is formed in single or multilayer form. The material used is usually a polyolefin resin, or a polyurethane resin for smooth processing, and mixtures thereof can also be used.

[0069] The above-mentioned plurality of battery cells 120 can be arranged in a first direction (for example, in the X-axis direction). In some embodiments, the first battery cell stack S1, the second battery cell stack S2, and the third battery cell stack S3 can be arranged in a first direction (for example, in the X-axis direction). In some embodiments, the fourth battery cell stack S4, the fifth battery cell stack S5, and the sixth battery cell stack S6 can be arranged in a first direction (for example, in the X-axis direction).

[0070] In some embodiments, the first battery cell stack S1 and the fourth battery cell stack S4 can be arranged in a second direction (e.g., the Y-axis direction). In some embodiments, the second battery cell stack S2 and the fifth battery cell stack S5 can be arranged in a second direction (e.g., the Y-axis direction). In some embodiments, the third battery cell stack S3 and the sixth battery cell stack S6 can be arranged in a second direction (e.g., the Y-axis direction).

[0071] Figure 4 is an exploded perspective view showing a thermal barrier pad 180 according to one embodiment of the present invention.

[0072] Referring to Figures 1 to 4, the battery pack 100 may further include a thermal barrier pad 180. The thermal barrier pad 180 can absorb the heat generated by the battery cell 120 and / or block or delay the transfer of the heat.

[0073] The thermal barrier pad 180 may include a porous heat-insulating absorbent material 180p and a heat-absorbing solution composition absorbed by the heat-insulating absorbent material 180p.

[0074] In some embodiments, the endothermic solution composition may contain about 0.20% to about 0.45% by weight of a surfactant, about 0.3% to about 5.0% by weight of a thickener, and about 60% to about 80% by weight of water.

[0075] <Surfactants>

[0076] In some embodiments, the surfactant may include cationic surfactants, anionic surfactants, nonionic surfactants, amphoteric surfactants, fluorinated surfactants, or silicone surfactants.

[0077] The cationic surfactants described above may include alkylamine salts, amine salts such as polyamines and amino alcohol fatty acid derivatives, alkyl quaternary ammonium salts, aromatic quaternary ammonium salts, pyridinium salts, or imidazolium salts.

[0078] The above-mentioned anionic surfactants may include fatty acid soaps such as sodium stearate and triethanolamine palmitate, alkyl ether carboxylic acids and their salts, condensate salts of amino acids and fatty acids, alkanesulfonates, alkenesulfonic acids, sulfonates of fatty acid esters, sulfonates of fatty acid amides, formalin condensate sulfonates, alkyl sulfate salts, secondary higher alcohol sulfate salts, alkyl and allyl ether sulfate salts, sulfate salts of fatty acid esters, sulfate salts of fatty acid alkylolamides, sulfate salts of belladonna oil and other similar substances, alkyl phosphates, ether phosphates, alkylallyl ether phosphates, amide phosphates, N-acyl lactates, N-acyl sarcosine salts, or N-acyl amino acid-based surfactants.

[0079] The above nonionic surfactants include glycerol, trimethylolpropane, trimethylolethane and their ethoxylates and propoxylates (e.g., glycerol propoxylate, glycerol ethoxylate, etc.), polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, sorbitan fatty acid ester, glycerin fatty acid ester, polyglycerin fatty acid ester, propylene glycol fatty acid ester, polyethylene glycol fatty acid ester, sucrose fatty acid ester, methyl glucoside fatty acid ester, alkyl polyglucoside, polyoxyethylene alkyl ether, polyoxypropylene alkyl ether, and polyoxyethylene Examples include alkylphenyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyoxyethylene propylene glycol fatty acid esters, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, polyoxyethylene phytostanol ethers, polyoxyethylene phytosterol ethers, polyoxyethylene cholesterol ethers, linear or branched polyoxyalkylene-modified organopolysiloxanes, linear or branched polyoxyalkylene-alkyl-comodified organopolysiloxanes, linear or branched polyglycerin-modified organopolysiloxanes, linear or branched polyglycerin-alkyl-comodified organopolysiloxanes, alkanolamides, sugar ethers, and sugar amides.

[0080] Examples of the above-mentioned amphoteric surfactants include betaine, aminocarboxylate salts, imidazoline derivatives, and amidoamine types.

[0081] The above-mentioned fluorinated surfactant can be a polymer of a fluorine atom-containing vinyl ether compound having a fluorinated alkyl group or a fluorinated alkylene ether group and a hydrophilic vinyl ether compound. The above-mentioned fluorinated surfactant may also be a block polymer. The fluorinated surfactant can also be a fluorine-containing polymer compound that includes repeating units derived from a (meth)acrylate compound having a fluorine atom and repeating units derived from a (meth)acrylate compound having two or more (preferably five or more) alkylene oxy groups (preferably ethylene oxy groups, propylene oxy groups).

[0082] A commercially available fluorine-based surfactant is MEGAFACE from DIC Corporation. (R) Product lines F-114, F-251, F-253, F-281, F-410, F-430, F-477, F-510, F-551, F-552, F-553, F-554, F-555, F-556, F-557, F-558, F-559, F-560, F-561, F-562, F-563, F-565, F-568, F-569, F-570, F-572, F-574, F-575, F-576, R-4, R-41, R-94, RS-56, RS-72-K, RS-75, RS-76-E, RS-76-NS, RS-78, RS-90, DS-21; 3M Fluorosurfactant (R) Product range includes FC-135, FC-170C, FC-430, FC-431, FC-4430, FC-4433, etc.; AGC's SURFLON (R) Product line S-211, S-221, S-231, S-232, S-241, S-242, S-243, S-420, S-431, S-386, S-611, S-647, S-651, S-653, S-656, S-658, F693; DuPONT's CPASTONE (R) Examples of product lines include, but are not limited to, FS-30, FS-65, FS-31, FS-3100, FS-34, FS-35, FS-50, FS-51, FS-60, FS-61, FS-63, FS-64, FS-81, FS-22, and FS-83.

[0083] The above-mentioned silicone-based surfactants are DOWSIL SH8400, SH8400 FLUID, FZ-2122, 67 Additive, 74 Additive, M Additive, and SF 8419. OIL (manufactured by Dow Dray Ltd.), TSF-4300, TSF-4445, TSF-4460, TSF-4452 (manufactured by Momentive Performance Materials), KP-341, KF-6000, KF-6001, KF-6002, KF-6003 (manufactured by Shin-Etsu Chemical Co., Ltd.), BYK-300, BYK-301, BYK-302, BYK-306, BYK-307, BYK-310, BYK-313, BYK-315N, BYK-320, BYK-322, BYK-323, BYK-325N, BYK-326, BYK-327, BYK-329, BYK-330, BYK-331, BYK-332, BYK-333, BYK-342, BYK-345, BYK-346, BYK-347, BYK-348, BYK -350, BYK-352, BYK-354, BYK-355, BYK-356, BYK-358N, BYK-359, BYK-360P, BYK- 361N, BYK-364P, BYK-366P, BYK-368P, BYK-370, BYK-375, BYK-377, BYK-378, BYK-381, BYK-390, BYK-392, BYK-394, BYK-3760, BYK-UV3510 (manufactured by BYK Chemie), DYNOL Examples include, but are not limited to, 360, DYNOL 604, DYNOL 607, DYNOL 800, DYNOL 810, the TEGO product line, Twin 4000, Twin 4100, and Twin 4200 (all manufactured by Evonik). In some embodiments, the above-mentioned silicone-based surfactant may include polydimethylsiloxane (PDMS).

[0084] The above endothermic solution composition may contain about 0.20% to about 0.45% by weight of the above surfactant. In some embodiments, the endothermic solution composition may contain the surfactant in a range of about 0.20% to about 0.45% by weight, about 0.21% to about 0.44% by weight, about 0.22% to about 0.43% by weight, about 0.23% to about 0.42% by weight, about 0.24% to about 0.41% by weight, about 0.25% to about 0.40% by weight, about 0.26% to about 0.39% by weight, about 0.27% to about 0.38% by weight, about 0.28% to about 0.37% by weight, about 0.29% to about 0.36% by weight, about 0.30% to about 0.35% by weight, about 0.31% to about 0.34% by weight, about 0.32% to about 0.33% by weight, or any two of these values.

[0085] If the amount of the surfactant contained in the above-mentioned endothermic solution composition is too low, the endothermic performance of the endothermic solution composition may be insufficient. If the amount of the surfactant contained in the above-mentioned endothermic solution composition is too high, the endothermic performance of the endothermic solution composition may become saturated, which may be economically disadvantageous.

[0086] <Thickening agent>

[0087] In some embodiments, the thickener may include carboxymethyl cellulose (CMC), carboxyethyl cellulose, polyvinyl alcohol (PVA), starch, polyethylene oxide (PEO), hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, or glucomannan.

[0088] The above endothermic solution composition may contain the above thickener in an amount of about 0.3% to about 5.0% by weight. In some embodiments, the above endothermic solution composition may contain the above thickener in an amount of about 0.5% to about 3.0% by weight. In some embodiments, the above endothermic solution composition may contain the above thickener in an amount of about 1% to about 2.2% by weight. In some embodiments, the above endothermic solution composition may contain the above thickener in an amount of about 0.3% to about 5.0% by weight, about 0.4% to about 4.5% by weight, about 0.5% to about 4.0% by weight, about 0.6% to about 3.5% by weight, about 0.7% to about 3.0% by weight, about 0.8% to about 2.5% by weight, about 0.9% to about 2.0% by weight, about 1% to about 1.5% by weight, or a range between any two of these values.

[0089] If the amount of the thickening agent contained in the above-mentioned endothermic solution composition is too low, the endothermic solution composition may leak. If the amount of the thickening agent contained in the above-mentioned endothermic solution composition is too high, the productivity of the endothermic solution composition may decrease.

[0090] In some embodiments, the endothermic solution composition may further contain an antifreeze agent. The antifreeze agent may include, for example, salts of CaCl2, NaCl, potassium acetate, or potassium formate; or short-chain alcohols or glycols such as isopropanol, butyl diglycol, ethylene glycol, diethylene glycol, dipropylene glycol, or propylene glycol, and may also include urea or glycerol.

[0091] The above endothermic solution composition may contain about 15% to about 35% by weight of the above antifreeze agent. In some embodiments, the above endothermic solution composition may contain about 20% to about 30% by weight of the above antifreeze agent.

[0092] In some embodiments, the endothermic solution composition may contain the antifreeze in an amount of about 15% to about 35% by weight, about 16% to about 34% by weight, about 17% to about 33% by weight, about 18% to about 32% by weight, about 19% to about 31% by weight, about 20% to about 30% by weight, about 21% to about 29% by weight, about 22% to about 28% by weight, about 23% to about 27% by weight, about 24% to about 26% by weight, or any two of these values.

[0093] If the amount of the antifreeze contained in the above-mentioned endothermic solution composition is too low, the endothermic solution composition may easily freeze at low temperatures. If the amount of the antifreeze contained in the above-mentioned endothermic solution composition is too high, the endothermic performance of the endothermic solution composition may decrease.

[0094] In some embodiments, the endothermic solution composition may contain about 60% to about 80% by weight of water. In some embodiments, the endothermic solution composition may have a range of about 60% to about 80% by weight of water, about 61% to about 79% by weight, about 62% to about 78% by weight, about 63% to about 77% by weight, about 64% to about 76% by weight, about 65% to about 75% by weight, about 66% to about 74% by weight, about 67% to about 73% by weight, about 68% to about 72% by weight, about 69% to about 71% by weight, or any two of these values.

[0095] If the amount of water contained in the above-mentioned heat-absorbing solution composition is too low, the heat-absorbing performance of the heat-absorbing solution composition may decrease. If the amount of water contained in the above-mentioned heat-absorbing solution composition is too high, the duration of heat absorption of the heat-absorbing solution composition may be shortened.

[0096] In some embodiments, the thermal barrier pad 180 may be provided on top of the battery cell 120. In some embodiments, the thermal barrier pad 180 may be provided between the upper case 170 and the battery cell 120. Hereinafter, the thermal barrier pad provided between the upper case 170 and the battery cell 120 may be referred to as the first thermal barrier pad 180.

[0097] The first thermal barrier pad 180 may have a predetermined area along a plane perpendicular to a third direction (for example, the Z-axis direction). The first thermal barrier pad 180 may include a heat dissipation pouch 180c having an internal space. The heat dissipation pouch 180c may constitute the appearance of the first thermal barrier pad 180. In some embodiments, the first thermal barrier pad 180 may include a heat insulating absorbent 180p and a heat-absorbing solution composition provided in the internal space of the heat dissipation pouch 180c. The heat dissipation pouch 180c includes substantially parallel first layers 180a and second layers 180b, and the internal space may be defined between the first layer 180a and the second layer 180b.

[0098] The heat dissipation pouch 180c may consist of a single layer or a laminate of two or more layers. In some embodiments, the heat dissipation pouch 180c may include an outermost resin layer made of an insulating material such as polyethylene terephthalate (PET) or nylon. In some embodiments, the heat dissipation pouch 180c may include a metal layer that maintains mechanical strength and prevents the penetration of moisture and oxygen. The metal layer may include, for example, aluminum or an alloy thereof. In some embodiments, the heat dissipation pouch 180c may include an inner resin layer made of a polyolefin-based material that has thermal adhesive properties and acts as a sealant.

[0099] In Figure 4, for illustrative purposes, the outer surface of the heat dissipation pouch 180c is shown to be perfectly flat. However, the heat dissipation pouch 180c may be deformable by external forces and may not be perfectly flat; it may be deformable at least partially by external forces.

[0100] The above-mentioned heat-absorbing solution composition may be absorbed by the above-mentioned heat-insulating absorbent material 180p and may include a material that can undergo a phase change in response to temperature changes. The above-mentioned heat-dissipating pouch 180c may be configured to be deformable in response to the phase change of the above-mentioned heat-absorbing solution composition.

[0101] In some embodiments, the thermal insulation absorbent 180p may include a porous thermal insulation material. The porous thermal insulation material may be, for example, glass fibers or silica fibers. In some embodiments, the thermal insulation absorbent 180p may include a non-woven fabric mainly composed of glass fibers or silica fibers. Here, "main component" means a component that accounts for more than 50% of the total by weight.

[0102] In some embodiments, the thermal insulation absorbent 180p may include an absorbent resin such as a super absorbent polymer (SAP). The super absorbent resin may be any substance known in the art and is not particularly limited. In some embodiments, the super absorbent resin may include polyacrylamide, polyacrylic acid, polymethacrylic acid, polyethylene oxide, polyvinyl alcohol, gelatin, polysaccharide, chitosan, sodium carboxymethylcellulose, or a combination thereof, but the present invention is not limited thereto. In some embodiments, the thermal insulation absorbent 180p may be in the form of a powder, granules, pellet, platelet, slab, etc., and is not particularly limited.

[0103] The above-mentioned heat-insulating absorbent material 180p may absorb a liquid endothermic solution composition. In some embodiments, the endothermic solution composition may include a material that can repeatedly vaporize and condense within the operating temperature range of the battery cell 120 and within and outside the atmospheric pressure range. For example, the endothermic solution composition may include a material that can vaporize or condense in a pressure range of about 1 atmosphere to about 10 atmospheres and a temperature range of about 70°C to about 130°C.

[0104] The above-mentioned heat-absorbing solution composition can be vaporized by the heat transferred from the battery cell 120 through the second layer 180b of the heat-dissipating pouch 180c. The vaporized heat-absorbing material exists in a gaseous state within the heat-dissipating pouch 180c but can condense and liquefy as it cools, and can be reabsorbed into the heat-insulating absorbent material 180p. The heat transferred from the battery cell 120 is used as a temperature increase and enthalpy of vaporization of the heat-absorbing material, so that the transfer of the heat to other adjacent battery cells 120 can be reduced or blocked.

[0105] In some embodiments, the first thermal barrier pad 180 may have a lamination portion 180m. In some embodiments, the lamination portion 180m may be a portion formed by fusing opposing laminate sheets of the first thermal barrier pad 180 (i.e., the first layer 180a and the second layer 180b). In some embodiments, the first thermal barrier pad 180 may be configured such that the lamination portion 180m is opened when a thermal event occurs inside, or so that a specific location of the lamination portion 180m is opened.

[0106] As shown in Figures 1 and 4, by placing the first thermal barrier pad 180 between the top surface of the battery cell 120 and the upper case 170, flame energy can be effectively weakened even if a thermal event occurs in a particular battery cell 120, and thermal damage to the upper case 170 can be mitigated or prevented.

[0107] Figure 5 is a perspective view of a thermal barrier pad 181 according to one embodiment of the present invention. Figure 6 is a schematic side cross-sectional view showing the thermal barrier pad 181 inserted between battery cells 120.

[0108] The lateral section shown in Figure 6 could be, for example, a section cut along the line VI-VI' in Figure 3.

[0109] Referring to Figures 5 and 6, the thermal barrier pad 181 may generally have a configuration that extends in a second direction (e.g., the Y-axis direction), which is the longitudinal direction of the battery cell 120. In some embodiments, the thermal barrier pad 181 extends in the second direction (e.g., the Y-axis direction) and can directly contact the side surface of an adjacent battery cell 120. Hereinafter, the thermal barrier pad provided on the side surface of the battery cell 120 may be referred to as the second thermal barrier pad 181.

[0110] The second thermal barrier pad 181 may have a predetermined area along a plane perpendicular to the first direction (for example, the X-axis direction). In some embodiments, the second thermal barrier pad 181 may be interposed between a pair of battery cells 120. One side surface 181a of the second thermal barrier pad 181 may be in direct contact with one of the battery cells 120. The other side surface 181b of the second thermal barrier pad 181 may be in direct contact with the remaining battery cell 120.

[0111] In some embodiments, the second thermal barrier pad 181 may be thermally connected to the lower case 110, allowing heat transferred from the battery cell 120 to be transferred to the plate portion 110P. In some embodiments, the second thermal barrier pad 181 may be thermally connected to the upper case 170 (see Figure 1). Here, "thermally connected" of the second thermal barrier pad 181 to an object can mean that most of the heat emitted from the second thermal barrier pad 181 is removed through that object, for example, more than 50% of the heat emitted from the second thermal barrier pad 181 is removed through that object.

[0112] In some embodiments, the plate portion 110P of the lower case 110 may include a heat sink 110FP. For example, the heat sink 110FP may include a channel configured for the flow of a cooling fluid inside. Thus, the heat transferred to the lower plate portion 110P via the second thermal barrier pad 181 can be smoothly removed by the cooling fluid flowing through the heat sink 110FP. For this purpose, the second thermal barrier pad 181 may be positioned closer to the lower case 110 than to the upper case 170.

[0113] In some embodiments, the second thermal barrier pads 181 can be arranged alternately with the battery cells 120, one at a time. In some embodiments, one second thermal barrier pad 181 can be provided for every two or more battery cells 120. That is, two or more battery cells 120 can be arranged between the two nearest adjacent second thermal barrier pads 181.

[0114] In some embodiments, the second thermal barrier pad 181 can be provided at both ends of a plurality of battery cells 120 provided within a single compartment space 119d in a first direction (e.g., the X-axis direction). In this case, thermal events occurring within one compartment space 119d can be effectively prevented or delayed from transferring to other adjacent compartment spaces 119d. In this case, the second thermal barrier pad 181 can be positioned to directly face the crossbeam 116.

[0115] In some embodiments, two battery cells 120 can be positioned between the two closest adjacent second thermal barrier pads 181. In this case, at least one side of any battery cell 120 is in contact with the second thermal barrier pad 181, so that even if a thermal event occurs in a battery cell 120, heat transfer to the adjacent battery cell 120 can be minimized.

[0116] Figure 7 is a front view of the second thermal barrier pad 181 according to one embodiment of the present invention illustrated in Figure 5. Figure 8 is a cross-sectional view showing a section obtained by cutting the second thermal barrier pad 181 along the line VIII-VIII' in Figure 7.

[0117] Referring to Figures 7 and 8, the second thermal barrier pad 181 has a porous heat-insulating absorbent material 180p having a first main surface 181p1 and a second main surface 181p2. The heat-insulating absorbent material 180p has absorbed a heat-absorbing solution composition. The first main surface 181p1 and the second main surface 181p2 may be generally parallel to each other.

[0118] A thermal conductive sheet 182 can be provided on at least one of the first main surface 181p1 and the second main surface 181p2 of the thermal insulation absorbent material 180p.

[0119] The thermal conductive sheet 182 may include a metallic material with excellent thermal conductivity. In some embodiments, the thermal conductive sheet 182 may include copper (Cu), aluminum (Al), zinc (Zn), tin (Sn), iron (Fe), or alloys thereof.

[0120] In some embodiments, the thermal conductive sheet 182 may have a thickness of about 5 μm to about 50 μm. In some embodiments, the thermal conductive sheet 182 may have a thickness in the range of about 5 μm to about 50 μm, about 10 μm to about 45 μm, about 15 μm to about 40 μm, about 20 μm to about 35 μm, about 25 μm to about 30 μm, or any two of these values.

[0121] If the thickness of the thermal conductive sheet 182 is too thin, the mechanical strength may be insufficient, making manufacturing difficult. If the thickness of the thermal conductive sheet 182 is too thick, the weight of the product may increase excessively, potentially raising manufacturing costs.

[0122] In some embodiments, the thermal conductive sheet 182 can be provided on the first main surface 181p1 of the thermal insulation absorbent material 180p. In other embodiments, the thermal conductive sheet 182 can be provided on the first main surface 181p1 and the second main surface 181p2 of the thermal insulation absorbent material 180p, as shown in Figure 8.

[0123] In some embodiments, the thermal conductive sheet 182 may be provided to substantially cover the entire surface of the first main surface 181p1 and / or the second main surface 181p2. In other embodiments, the thermal conductive sheet 182 may be provided to cover a portion of the surface of the first main surface 181p1 and / or the second main surface 181p2.

[0124] In some embodiments, the heat conductive sheet 182 may be in the form of a flat plate. In other embodiments, the heat conductive sheet 182 may be in the form of a mesh. In some embodiments, the heat conductive sheet 182 may be in the form of a flat plate having holes.

[0125] The heat dissipation pouch 180c can be configured to surround the heat insulating material 180p and the heat conductive sheet 182. The heat dissipation pouch 180c has interleaving sections 181m facing each other on the outside of the heat insulating material 180p. In some embodiments, the interleaving sections 181m can be thermally fused to seal the heat insulating material 180p and the heat conductive sheet 182 from the outside.

[0126] A free space 181f can be provided on one side of the heat-insulating absorbent material 180p within the heat-dissipating pouch 180c. The free space 181f can absorb heat and contain some components of the heat-absorbing solution composition vaporized from the heat-insulating absorbent material 180p. The free space 181f can be provided between the heat-insulating absorbent material 180p and the interleaving paper portion 181m. In Figure 7, the free space 181f is shown to be located only in the lateral direction of the heat-insulating absorbent material 180p, but the present invention is not limited thereto. In some embodiments, the free space 181f can also be located above the heat-insulating absorbent material 180p with respect to the arrangement in Figure 7.

[0127] The configuration and effects of the present invention will be described in more detail below using specific examples and comparative examples. However, these examples are merely intended to make the present invention easier to understand and are not intended to limit the scope of the present invention.

[0128] <Comparative Example 1> A polyacrylonitrile-based superabsorbent resin in the form of a flat plate was used as the thermal insulation absorbent material. After water was absorbed into the thermal insulation absorbent material as an endothermic solution composition, a 0.01 mm thick copper foil was placed on both sides of the thermal insulation absorbent material as a thermal conductive sheet.

[0129] The above-mentioned heat-insulating absorbent material and thermal conductive sheet were surrounded by a heat-dissipating pouch 180c, and then sealed by heat fusion to produce a thermal barrier pad. The heat-dissipating pouch 180c was used when manufacturing pouch-type battery cells and was a standard laminate sheet containing an aluminum layer.

[0130] <Example 1> A thermal barrier pad was prepared in the same manner as in Comparative Example 1, except that the endothermic solution composition contained 0.5% by weight of CMC as a thickener and 0.25% by weight of PDMS as a surfactant.

[0131] <Example 2> A thermal barrier pad was prepared in the same manner as in Comparative Example 1, except that the endothermic solution composition contained 1% by weight of CMC as a thickener and 0.25% by weight of PDMS as a surfactant.

[0132] <Example 3> A thermal barrier pad was prepared in the same manner as in Comparative Example 1, except that the endothermic solution composition contained 2% by weight of CMC as a thickener and 0.25% by weight of PDMS as a surfactant.

[0133] <Example 4> A thermal barrier pad was prepared in the same manner as in Comparative Example 1, except that the endothermic solution composition contained 1% by weight of CMC as a thickener, 0.3% by weight of PDMS as a surfactant, and 25% by weight of CaCl2 as an antifreeze.

[0134] A stainless steel plate was placed on one surface of the thermal barrier pads manufactured in Comparative Example 1 and Examples 1 to 4, and the temperature change of the thermal barrier pad over time was measured while heating it with a torch. The temperature of the thermal barrier pad was measured by inserting a thermocouple between the thermal barrier pad and the stainless steel plate.

[0135] Figure 9 is a graph showing the temperature change over time measured for Comparative Example 1 and Examples 1 to 4, respectively.

[0136] Referring to Figure 9, it was observed that the thermal barrier pad of Comparative Example 1 experienced a rapid temperature increase slightly more than 150 seconds after its surface temperature was maintained at 100°C.

[0137] On the other hand, it was observed that the thermal barrier pads of Examples 1 to 3 experienced a rapid temperature increase after 240 to 280 seconds following the maintenance of a surface temperature of 100°C. Therefore, it can be seen that the thermal barrier pads of Examples 1 to 3 have superior heat absorption and heat insulation performance compared to the thermal barrier pad of Comparative Example 1.

[0138] Furthermore, it was observed that the thermal barrier pad of Example 4 gradually increased in temperature after approximately 300 seconds following the initial maintenance of a surface temperature of 100°C, and remained below 150°C even after 500 seconds. In other words, it was observed that the thermal barrier pad of Example 4 had superior heat absorption and heat insulation performance not only compared to the thermal barrier pad of Comparative Example 1, but also compared to the thermal barrier pads of Examples 1 to 3.

[0139] <Example 5> A thermal barrier pad was prepared in the same manner as in Comparative Example 1, except that the endothermic solution composition contained 1% by weight of CMC as a thickener, 0.3% by weight of PDMS as a surfactant, and 20% by weight of CaCl2 as an antifreeze.

[0140] <Example 6> A thermal barrier pad was prepared in the same manner as in Comparative Example 1, except that the endothermic solution composition contained 1% by weight of CMC as a thickener, 0.3% by weight of PDMS as a surfactant, and 15% by weight of CaCl2 as an antifreeze.

[0141] <Example 7> A thermal barrier pad was prepared in the same manner as in Comparative Example 1, except that the endothermic solution composition contained 1% by weight of CMC as a thickening agent, 0.3% by weight of PDMS as a surfactant, and 10% by weight of CaCl2 as an antifreeze agent.

[0142] <Example 8> A thermal barrier pad was prepared in the same manner as in Comparative Example 1, except that the endothermic solution composition contained 2% by weight of CMC as a thickening agent, 0.25% by weight of PDMS as a surfactant, and 15% by weight of CaCl2 as an antifreeze agent.

[0143] <Example 9> A thermal barrier pad was prepared in the same manner as in Comparative Example 1, except that the endothermic solution composition contained 2.5% by weight of CMC as a thickening agent, 0.25% by weight of PDMS as a surfactant, and 15% by weight of CaCl2 as an antifreeze agent.

[0144] <Comparative Example 2> A thermal barrier pad was prepared in the same manner as in Comparative Example 1, except that the endothermic solution composition contained 0.2% by weight of CMC as a thickener and 0.25% by weight of PDMS as a surfactant.

[0145] <Comparative Example 3> A thermal barrier pad was prepared in the same manner as in Comparative Example 1, except that the endothermic solution composition contained 8% by weight of CMC as a thickener, 0.3% by weight of PDMS as a surfactant, and 10% by weight of CaCl2 as an antifreeze.

[0146] <Comparative Example 4> A thermal barrier pad was prepared in the same manner as in Comparative Example 1, except that the endothermic solution composition contained 1% by weight of CMC as a thickener and 0.1% by weight of PDMS as a surfactant.

[0147] <Comparative Example 5> A thermal barrier pad was prepared in the same manner as in Comparative Example 1, except that the endothermic solution composition contained 2% by weight of CMC as a thickener and 0.5% by weight of PDMS as a surfactant.

[0148] The endothermic duration was measured for the thermal barrier pads manufactured in Examples 1 to 9 and Comparative Examples 1 to 5. The endothermic duration was defined as the time interval between the point in time when the temperature on one side of the thermal barrier pad reached 100°C and the point in time when it reached 150°C.

[0149] In order to increase the temperature of the thermal barrier pads manufactured in Examples 1 to 9 and Comparative Examples 1 to 5, a stainless steel plate was placed between the thermal barrier pad and the stainless steel plate and heated with a torch. The temperature of the thermal barrier pad was measured by inserting a thermocouple between the thermal barrier pad and the stainless steel plate.

[0150] The endothermic durations measured as described above are summarized in Table 1.

[0151] [Table 1]

[0152] It was observed that leakage of the endothermic solution composition occurred when the thickening agent was either absent (Comparative Example 1) or present in too small a quantity (Comparative Example 2).

[0153] When the thickening agent was excessively present (Comparative Example 3), it was observed that no leakage of the endothermic solution composition occurred. Furthermore, it was observed that the duration of endothermic activity did not improve significantly in this case. Although the present invention is not limited by any particular theory, it is understood that if the content of the thickening agent is excessive, the tension formed at the interface between the endothermic solution composition and the heat insulating absorbent increases excessively, limiting the heat absorption and heat insulating performance of the thermal barrier pad.

[0154] Even when the surfactant content was too low (Comparative Example 4), the endothermic duration did not improve. Although the present invention is not limited by any particular theory, this is presumed to be due to excessive tension formed at the interface between the endothermic solution composition and the heat insulating absorbent when the surfactant content is too low.

[0155] It was shown that the endothermic duration did not improve even when the surfactant content was too high (Comparative Example 5). Comparing Example 3 and Comparative Example 5, the surfactant concentrations were 0.25% by weight and 0.5% by weight, respectively, and other conditions were almost the same. An optimal surfactant concentration range exists, as the endothermic duration in Example 3 is significantly longer than that of Comparative Example 5.

[0156] Figure 10 is a perspective view of a battery pack 100a according to another embodiment of the present invention. The battery pack 100a of the embodiment shown in Figure 10 differs from the battery pack 100 shown in Figure 1 in the size and number of thermal barrier pads 180. Therefore, the following explanation will focus on these differences, and the explanation of overlapping parts will be omitted.

[0157] Referring to Figure 10, one thermal barrier pad 180 can be assigned to each battery cell stack S1, S2, ..., S6. In this case, since damaged parts can be replaced for each compartment space 119d (see Figure 2), repairs may be easier.

[0158] Figure 11 is an exploded perspective view of a battery module 120M according to one embodiment of the present invention. Figure 12 is a perspective view of a battery module 120M according to one embodiment of the present invention.

[0159] Referring to Figures 11 and 12, the battery module 120M may include a battery cell 120, module cases 122 and 123 that house the battery cell 120, and end plates 124 and 125 that are coupled to the front and rear surfaces of the module cases 122 and 123.

[0160] In some embodiments, the battery cell 120 may be, for example, a stack of multiple pouch-type battery cells 120a. In some embodiments, the battery cell 120 may be a stack of multiple prismatic battery cells.

[0161] In some embodiments, second thermal barrier pads 181 can be provided at both ends of the battery cell 120 in the first direction (X-axis direction). The specific configuration of the second thermal barrier pad 181 has been described with reference to Figures 5 and 6, so a redundant explanation will be omitted here. In some embodiments, the second thermal barrier pad 181 can also be provided between the multiple battery cells 120.

[0162] In some embodiments, the module cases 122, 123 may include a lower case 122 and an upper case 123. In Figure 11, a U-shaped frame with side plates 122b and a bottom plate 122a is shown as the lower case 122, but an ordinary technician can understand that other forms of the lower case 122 may be applied. Needless to say, the form of the module cases 122, 123 is not limited to those disclosed in Figure 11, and other forms of module cases may be applied as long as they can stably accommodate the battery cells 120.

[0163] A busbar frame BFA can be attached to the front and rear of the battery cell 120. The busbar frame BFA can be fitted with busbars B for connecting the electrode leads of the battery cell, and busbars B for electrically connecting to other battery modules or externally.

[0164] In some embodiments, front and rear end plates 124 and 125 can be positioned on the front and rear surfaces of the battery cell 120 to protect the busbar frame BFA and the battery cell 120. The front and rear end plates 124 and 125 can be coupled to the module cases 122, 123 and / or the busbar frame BFA.

[0165] In some embodiments, the module cases 122 and 123 may be provided with venting holes H to discharge gas from within the module. In some embodiments, the upper case 123 may be provided with venting holes H.

[0166] A TIM layer 122t containing thermal resin can be placed on the bottom plate 122a of the lower case 122. The TIM layer 122t on the bottom plate 122a can fix the battery cell 120 to the bottom plate 122a. Furthermore, the TIM layer 122t can transfer the heat generated by the battery cell 120 to the bottom plate 122a of the lower case 122.

[0167] In some embodiments, an additional TIM layer (not shown) can be provided on the inner surface of the upper case 123. That is, an additional TIM layer can be placed between the upper case 123 and the upper surface of the battery cell 120.

[0168] The battery cells 120 are mounted on the lower case 122 of the U-shaped frame, and the upper case 123 is joined to the lower case 122 by welding or the like, so that the battery cells 120 can be housed in the module cases 122, 123. In some embodiments, at least one second thermal barrier pad 181 can be provided between the battery cells 120. The second thermal barrier pad 181 can be provided at both ends of the battery cells 120 in a first direction (e.g., in the X-axis direction) as housed in the module cases 122, 123. In this case, the second thermal barrier pad 181 can be in direct contact with the side plate 122b of the lower case 122.

[0169] By interposing a busbar frame BFA on the front and rear surfaces of the battery cell 120, and connecting the front end plate 124 and the rear end plate 125, the battery module can be completed as shown in Figure 12. The heat transferred to the thermal barrier structure 128 can be transferred to the pack housing 101 via the lower case 122 and / or upper case 123.

[0170] In some embodiments, a cooling device may be provided in at least one of the upper case 123 and the lower case 122. In some embodiments, the upper case 123 may include two spaced-apart plates, and a cooling channel may be provided in the spaced portion. In some embodiments, the bottom plate 122a may include two spaced-apart plates, and a cooling channel may be provided in the spaced portion.

[0171] In some embodiments, the battery module 120M may be provided with coupling portions F2 for coupling to a corresponding structure within the battery pack 100. In some embodiments, coupling portions F2 with fastening holes h2 may be provided on both sides of the end plates 124, 125 of the battery module 120M for coupling to the structure supporting the battery module 120M, etc.

[0172] Multiple of the above-mentioned battery modules 120M can be placed within the battery pack 100.

[0173] As shown in Figures 11 and 12, when the lower case 122 is provided with a TIM layer 122t, the bottom plate 122a side of the lower case 122 can be coupled to the plate portion 110P of the lower case 110 of the battery pack 100. In some embodiments, a thermal barrier pad 180 may be provided instead of the TIM layer 122t.

[0174] Since the second thermal barrier pads 181 are placed at both ends of the battery cells 120 housed in module cases 122 and 123, the transfer of thermal events occurring in a particular battery module 120M to other adjacent battery modules 120M can be effectively prevented or delayed.

[0175] Figure 13 is a schematic side view showing an electrified vehicle 10 according to one embodiment of the present invention. Figure 14 is a schematic diagram conceptually showing the battery pack 100 and other components mounted on the electric vehicle 10.

[0176] Referring to Figures 13 and 14, an electric vehicle 10 according to one embodiment of the present invention may include at least one battery pack 100. The electric vehicle 10 may include, for example, a vehicle body having a housing space for housing at least one battery pack 100. For example, the electric vehicle 10 may be a battery electric vehicle (BEV), a plug-in hybrid-electric vehicle (PHEV), or a full hybrid-electric vehicle (FHEV).

[0177] The electric vehicle 10 may include one or more electrical machines 214 mechanically coupled to one or more gearboxes or hybrid transmissions 216. The electrical machines 214 can operate as motors or generators. Furthermore, if the electric vehicle 10 is a PHEV or FHEV, the electric vehicle 10 may include an engine 218, and the hybrid transmission 216 may be mechanically coupled to the engine 218.

[0178] Furthermore, the hybrid transmission 216 can be mechanically coupled to a drive shaft 220 which is mechanically coupled to a wheel 222. The electrical machine 214 may propel or decelerate in response to the on / off status of the engine 218, and may also act as a generator to recover energy. The electrical machine 214 can reduce emissions by allowing the engine 218 to operate at a more efficient speed, and under certain conditions the electric vehicle 10 can operate in electric mode with the engine 218 turned off. When the electric vehicle 10 is a BEV, the engine 218 is omitted.

[0179] The battery pack 100 stores the energy used by the electrical machine 214, and has been described with reference to Figures 1 to 12, so a redundant explanation will be omitted. The battery pack 100 can provide a high-voltage direct current (DC) output. The contactor module 242 may include one or more contactors configured to isolate the battery pack 100 from the high-voltage bus 252 when open, and to connect the battery pack 100 to the high-voltage bus 252 when closed.

[0180] One or more inverters 226 can be electrically connected to the high-voltage bus 252. The inverters 226 can also be connected to the electrical machine 214 and can transfer energy in both directions between the battery pack 100 and the electrical machine 214. For example, the battery pack 100 can provide a DC voltage while the electrical machine 214 is operating on three-phase AC. The inverters 226 can convert the DC voltage to a three-phase AC current so that the electrical machine 214 can operate. In regeneration mode, the inverters 226 can convert the three-phase AC current from the electrical machine 214 to a DC voltage that can be applied to the battery pack 100.

[0181] In some embodiments, the battery pack 100 can provide energy for other electrical systems of the vehicle in addition to the energy for propelling the vehicle. The electric vehicle 10 may include a DC / DC converter module 228, which converts a high-voltage DC output from a high-voltage bus 252 to a low-voltage DC level on a low-voltage bus 254 suitable for a low-voltage load 256. The output of the DC / DC converter module 228 can be electrically connected to an auxiliary battery 230 (e.g., a 12V battery) to charge the auxiliary battery 230. The low-voltage load 256 can be electrically connected to the auxiliary battery 230 via the low-voltage bus 254. One or more high-voltage loads 246 can be connected to the high-voltage bus 252. The high-voltage loads 246 may be, for example, a fan, an electric heating element, and / or an air conditioner compressor.

[0182] The electric vehicle 10 can be configured to recharge the battery pack 100 with an external power supply 236. In some embodiments, the external power supply 236 can be electrically connected to electric vehicle supply equipment (EVSE) 238. The external power supply 236 can supply DC or AC power to the EVSE 238, and the EVSE 238 may include a circuit that manages and controls the energy transfer between the external power supply 236 and the electric vehicle 10.

[0183] The EVSE 238 may include a charging connector 240 that can be connected to a charging port 234 of the electric vehicle 10. The charging port 234 may be any port that can transmit power from the EVSE 238 to the electric vehicle 10. The charging port 234 may be electrically connected to a power conversion module 232. The power conversion module 232 processes the power from the EVSE 238 and converts it to a voltage and current level suitable for the battery pack 100.

[0184] In some embodiments, the battery pack 100 can be electrically connected to the auxiliary battery 230. The auxiliary battery 230 can be configured to supply the power necessary to perform some of the functions of the battery pack 100.

[0185] All of the functions of the electric vehicle 10 described above can be controlled by the system controller 248.

[0186] Although embodiments of the present invention have been described in detail above, any person with ordinary skill in the art to which the present invention pertains can modify and implement the present invention in various ways without departing from the spirit and scope of the invention as defined in the appended claims. Therefore, any future modifications to embodiments of the present invention will not depart from the art of the present invention.

Claims

1. A porous heat-absorbing material having a first main surface and a second main surface, The heat-absorbing solution composition absorbed by the aforementioned heat-insulating absorbent material, A thermal conductive sheet covering at least one of the first main surface and the second main surface of the thermal insulation absorbent, A heat dissipation pouch containing a metal layer surrounds the aforementioned heat-insulating absorbent material and the aforementioned heat-conducting sheet, Includes, The aforementioned heat-absorbing solution composition is Surfactants are present in an amount of approximately 0.20% to 0.45% by weight, Thickening agent: approximately 0.3% to approximately 5.0% by weight, Water is present in a composition of approximately 60% to 80% by weight. A thermal barrier pad, including [a specific component].

2. The thermal barrier pad according to claim 1, wherein the thickening agent comprises carboxymethylcellulose (CMC), carboxyethylcellulose, polyvinyl alcohol (PVA), starch, polyethylene oxide (PEO), hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, or glucomannan.

3. The thermal barrier pad according to claim 1, wherein the endothermic solution composition contains about 15% to about 35% by weight of an antifreeze agent.

4. The aforementioned antifreeze agent is CaCl ２ A thermal barrier pad according to claim 3, comprising NaCl, potassium acetate, potassium formate, isopropanol, butyl diglycol, ethylene glycol, diethylene glycol, dipropylene glycol, propylene glycol, urea, and / or glycerol.

5. The thermal barrier pad according to claim 3, wherein the endothermic solution composition contains about 20% to about 30% by weight of an antifreeze agent.

6. The thermal barrier pad according to claim 3, wherein the endothermic solution composition contains about 23% to about 27% by weight of an antifreeze agent.

7. The thermal barrier pad according to claim 1, wherein the endothermic solution composition contains about 0.5% to about 3% by weight of a thickening agent.

8. The thermal barrier pad according to claim 1, wherein the endothermic solution composition contains about 1% to about 2.2% by weight of a thickening agent.

9. The thermal barrier pad according to claim 1, wherein the surfactant is a silicon (Si)-based surfactant.

10. The thermal barrier pad according to claim 9, wherein the surfactant comprises polydimethylsiloxane (PDMS).

11. The thermal barrier pad according to claim 1, wherein the thermal conductive sheet comprises copper, aluminum, zinc, tin, iron, or an alloy thereof.

12. The thermal barrier pad according to claim 11, wherein the thermal conductive sheet is a copper sheet or a copper alloy sheet and has a thickness of about 5 μm to about 50 μm.

13. The thermal barrier pad according to claim 1, wherein the thermal insulation absorbent material comprises a non-woven fabric mainly composed of silica fibers.

14. Pack case and A plurality of secondary batteries housed in the aforementioned pack case and stacked in a first direction, A thermal barrier pad according to any one of claims 1 to 13, provided between the plurality of secondary batteries, Includes a battery pack.

15. Module case and A plurality of secondary batteries housed within the module case and stacked in a first direction, A thermal barrier pad according to any one of claims 1 to 13, provided between the plurality of secondary batteries, A battery module, including the battery module.

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