Thermal barrier pad, battery pack and battery module

Abstract

There is provided a thermal barrier pad comprising: a porous insulating absorber having a first major surface and a second major surface; an endothermic solution composition absorbed in the insulating absorber; a thermally conductive sheet covering at least one of the first main surface and the second main surface of the heat insulating absorber; and a heat dissipation pouch surrounding the thermally insulating absorber and the thermally conductive sheet and including a metal layer, in which the endothermic solution composition includes: about 0.20 wt.% to about 0.45 wt.% of a surfactant; from about 0.3 wt.% to about 5.0 wt.% of a thickener; and from about 60 wt.% to about 80 wt.% water.

Description

Technical Field

[0001] This disclosure relates to thermal barrier pads, battery packs and battery modules, and more specifically, to thermal barrier pads capable of effectively preventing or delaying the transfer of heat generated from a battery cell to adjacent other battery cells, and battery packs and battery modules including the thermal barrier pads.

[0002] This application claims priority to 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, the entire contents of which are incorporated herein by reference. Background Technology

[0003] Rechargeable batteries are batteries that can be recharged and discharged, unlike primary batteries which cannot be recharged. They are widely used in electronic devices such as mobile phones, laptops, cameras, and electric vehicles. In particular, lithium-ion rechargeable batteries have a larger capacity and higher energy density per unit weight compared to nickel-cadmium or nickel-metal hydride batteries, thus their utilization rate is rapidly increasing.

[0004] Various structural and / or manufacturing methods have been proposed and applied to produce secondary batteries, and various means have been designed to improve the quality of secondary batteries. Summary of the Invention

[0005] Technical issues

[0006] The first technical problem to be solved by this disclosure is to provide a thermal barrier pad that can effectively prevent or delay the transfer of heat generated from a battery cell to other adjacent battery cells.

[0007] The second technical problem to be solved by this disclosure is to provide a battery pack including a thermal barrier pad that can effectively prevent or delay the transfer of heat generated from a battery cell to other adjacent battery cells.

[0008] The third technical problem to be solved by this disclosure is to provide a battery module including a thermal barrier pad that can effectively prevent or delay the transfer of heat generated from a battery cell to other adjacent battery cells.

[0009] Technical solution

[0010] To address the first technical problem, this disclosure provides a thermal barrier pad comprising: a porous heat-absorbing material having a first primary surface and a second primary surface; a heat-absorbing solution composition absorbed within the heat-absorbing material; a heat-conducting sheet covering at least one of the first primary surface and the second primary surface of the heat-absorbing material; and a heat-dissipating bag surrounding the heat-absorbing material and the heat-conducting sheet and including a metal layer, wherein the heat-absorbing solution composition comprises: about 0.20 wt.% to about 0.45 wt.% of a surfactant; about 0.3 wt.% to about 5.0 wt.% of a thickener; and about 60 wt.% to about 80 wt.% of water.

[0011] 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.

[0012] In some embodiments, the endothermic solution composition may include about 15 wt.% to about 35 wt.% of an antifreeze.

[0013] In some embodiments, the antifreeze may include CaCl2, NaCl, potassium acetate, potassium formate, isopropanol, butyl diethylene glycol, ethylene glycol, diethylene glycol, dipropylene glycol, propylene glycol, urea, and / or glycerin.

[0014] In some embodiments, the endothermic solution composition may include about 20 wt.% to about 30 wt.% of an antifreeze.

[0015] In some embodiments, the endothermic solution composition may include about 23 wt.% to about 27 wt.% of an antifreeze.

[0016] In some embodiments, the endothermic solution composition may include about 0.5 wt.% to about 3 wt.% of a thickener.

[0017] In some embodiments, the endothermic solution composition may include about 1 wt.% to about 2.2 wt.% of a thickener.

[0018] In some embodiments, the surfactant may be a silicon (Si) based surfactant.

[0019] In some embodiments, the surfactant may include polydimethylsiloxane (PDMS).

[0020] In some embodiments, the heat-conducting sheet may include copper, aluminum, zinc, tin, iron, or alloys thereof.

[0021] In some embodiments, the heat-conducting sheet may be a copper sheet or a copper alloy sheet, and the heat-conducting sheet may have a thickness of about 5 μm to about 50 μm.

[0022] In some embodiments, the heat-absorbing material may include a nonwoven fabric with silica fiber as the main component.

[0023] To address the second technical problem, this disclosure provides a battery pack comprising: a housing; a plurality of secondary batteries housed in the housing and stacked along a first direction; and a thermal barrier pad disposed between the plurality of secondary batteries.

[0024] To address the third technical problem, this disclosure provides a battery module comprising: a module housing; a plurality of secondary batteries housed in the module housing and stacked along a first direction; and a thermal barrier pad disposed between the plurality of secondary batteries.

[0025] Beneficial effects

[0026] The thermal barrier pad disclosed herein can effectively prevent or delay the transfer of heat generated from stacked battery cells to adjacent battery cells.

[0027] The technical effects achievable in the exemplary embodiments of this disclosure are not limited to those described above, and those skilled in the art can clearly derive and understand other effects not mentioned from the following description. In other words, those skilled in the art can also obtain unintended effects from the exemplary embodiments of this disclosure. Attached Figure Description

[0028] Figure 1 This is a perspective view of a battery pack according to an exemplary embodiment of the present disclosure.

[0029] Figure 2 This is a perspective view illustrating some components of a battery pack according to an exemplary embodiment of the present disclosure.

[0030] Figure 3 This is an enlarged perspective view illustrating a battery unit installed in a lower casing according to an embodiment of the present disclosure.

[0031] Figure 4 This is an exploded perspective view of a thermal barrier pad according to an embodiment of the present disclosure.

[0032] Figure 5 This is a perspective view of a thermal barrier pad according to an embodiment of the present disclosure.

[0033] Figure 6 This is a schematic side cross-section view of a thermal barrier pad inserted between battery cells.

[0034] Figure 7 It is based on Figure 5 The front view of the thermal barrier pad of an embodiment of the present disclosure is shown.

[0035] Figure 8 It is illustrated along Figure 7 A cross-sectional view of the thermal barrier pad cut by line VIII-VIII'.

[0036] Figure 9 It is a graph depicting the temperature change over time for the thermal barrier pads measured for Comparative Example 1 and Examples 1 to 4, respectively.

[0037] Figure 10 This is a perspective view of a battery pack according to another example of this disclosure.

[0038] Figure 11 This is an exploded perspective view of a battery module according to an embodiment of the present disclosure.

[0039] Figure 12 This is a perspective view of a battery module according to an embodiment of the present disclosure.

[0040] Figure 13 The illustration is a schematic side view of an electrified vehicle according to an embodiment of the present disclosure.

[0041] Figure 14 It is a conceptual illustration of a battery pack and other components installed in an electrified vehicle. Detailed Implementation

[0042] In the following, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. However, embodiments of the present disclosure can be modified in various different ways and should not be construed as limiting the scope of the present disclosure to the following embodiments. Preferably, embodiments of the present disclosure are intended to provide a more comprehensive explanation of the disclosure to those skilled in the art. Throughout this document, the same reference numerals refer to the same elements. Furthermore, various elements and areas are schematically illustrated in the drawings. Therefore, the present disclosure is not limited to the relative dimensions or spacing shown in the drawings.

[0043] Terms such as "first" and "second" may be used to describe various components, but the components are not limited by these terms. These terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component, and vice versa, without departing from the scope of the present disclosure.

[0044] The terminology used in this specification is for illustrative purposes only and is not intended to limit the scope of this disclosure. Unless the context clearly indicates otherwise, singular expressions include plural expressions. The terms “comprising,” “including,” and “having” as used herein refer to the presence of a feature, number, step, action, component, or element or combination thereof described in the specification, and it should be understood that the possibility of the presence or addition of one or more other features, numbers, steps, actions, components, elements, or combinations thereof is not excluded in advance.

[0045] Unless otherwise defined, all terms used herein, including technical and scientific terms, shall have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Furthermore, it will be understood that terms such as commonly used, dictionary-defined terms shall be interpreted as having the same meaning as they have in the context of the art to which they relate, and shall not be interpreted as having an overly formal meaning unless expressly defined herein.

[0046] When some implementation methods can be carried out in other ways, a particular order of processes may be executed in a different order than that described. For example, two processes described consecutively may be executed substantially simultaneously, or they may be executed in the reverse order of that described.

[0047] For example, in the accompanying drawings, variations in the depicted form can be expected depending on manufacturing techniques and / or tolerances. Therefore, embodiments of this disclosure should not be construed as limited to specific forms within the areas shown herein, and should include variations in form, such as those resulting from manufacturing processes. All terms “and / or” as used herein include each combination of one or more of the mentioned components.

[0048] Figure 1 This is a perspective view of a battery pack 100 according to an exemplary embodiment of the present disclosure.

[0049] Figure 2 This is a perspective view illustrating some components of a battery pack 100 according to an exemplary embodiment of the present disclosure.

[0050] exist Figure 1 and Figure 2 In the diagram, the battery pack 100 is shown as being defined in an orthogonal coordinate system defined by a first direction perpendicular to each other along the X-axis, a second direction perpendicular to each other along the Y-axis, and a third direction perpendicular to each other along the Z-axis. However, the first direction, the second direction, and the third direction are not particularly restricted, as long as they are perpendicular to each other.

[0051] Reference Figure 1 and Figure 2The battery pack 100 may include a lower box 110, battery cells 120, a central beam 130, a crossbeam 116, multiple venting devices 140, multiple first recessed guides 151, multiple second recessed guides 153, a pack liner 160, and an upper box 170. The battery pack 100 may be the final form of a battery system installed in a motor vehicle or the like.

[0052] The housing 101 that defines the appearance of the battery pack 100 may include a lower box 110 and an upper box 170.

[0053] The lower housing 110 provides a receiving space 119 for mounting a plurality of battery cells 120. In some embodiments, the lower housing 110 may include a plate member 110P and sidewalls 110S. Two directions substantially parallel to the plate member 110P are defined as a first direction (e.g., the X-axis direction) and a second direction (e.g., the Y-axis direction), and a direction substantially perpendicular to the plate member 110P of the housing 110 is defined as a third direction (e.g., the Z-axis direction). Each of the X-axis, Y-axis, and Z-axis directions may be substantially perpendicular to each other. Unless otherwise stated, the direction definitions in the following figures are the same.

[0054] Multiple battery cells 120 may be arranged on a plate member 110P of the lower housing 110. The plate member 110P may support the multiple battery cells 120. The plate member 110P may include a substantially parallel upper surface and a lower surface. The upper surface of the plate member 110P may face the multiple battery cells 120. The lower surface of the plate member 110P is the surface opposite to the upper surface of the plate member 110P.

[0055] Sidewall 110S can horizontally surround multiple battery cells 120. Sidewall 110S can protect multiple battery cells 120 from the side. Sidewall 110S can include a first sidewall 111, a second sidewall 112, a third sidewall 113, and a fourth sidewall 114. The first to fourth sidewalls 111, 112, 113, and 114 can be fixed to each other by methods such as friction stir welding or spot welding, but there are no particular limitations.

[0056] The first sidewall 111 and the second sidewall 112 may be substantially perpendicular to a second direction (e.g., the Y-axis direction). Each of the third sidewall 113 and the fourth sidewall 114 may be substantially perpendicular to a first direction (e.g., the X-axis direction). In some embodiments, the first sidewall 111 and the second sidewall 112 may cover the side surface of the plate member 110P. In some embodiments, the third sidewall 113 and the fourth sidewall 114 may be disposed on the plate member 110P.

[0057] In some embodiments, the first to fourth sidewalls 111, 112, 113, 114 can be provided by an extrusion process. According to an exemplary embodiment, the first to fourth sidewalls 111, 112, 113, 114 may include an internal hollow space, and therefore, the sidewall 110S can be lightweight. According to an exemplary embodiment, the hollow space of the first to fourth sidewalls 111, 112, 113, 114 can be either a gas exhaust path or a coolant passage.

[0058] In the following description, the technical concept of this disclosure will be described with reference to an embodiment in which each of the plurality of battery cells 120 does not include a module frame. However, this is a non-limiting example and does not limit the technical concept of this disclosure in any sense. Based on the description herein, those skilled in the art will be able to readily obtain battery packs employing battery modules that include a module frame exposing one edge of the battery cells.

[0059] The accommodating space 119 can be divided into two or more compartment spaces 119d by one or more compartment beams 130, 116. The compartment beams 130, 116 may include a central beam 130. In some embodiments, the compartment beams 130, 116 may include one or more crossbeams 116.

[0060] The central beam 130 can isolate the components mounted on the lower box 110 from each other. Therefore, the central beam 130 can protect the multiple battery cells 120 while preventing unwanted short circuits between the multiple battery cells 120.

[0061] A central beam 130 may extend between a third sidewall 113 and a fourth sidewall 114. The central beam 130 may extend along a first direction (e.g., the X-axis direction). The central beam 130 may contact the third sidewall 113 and the fourth sidewall 114. The central beam 130 may isolate multiple battery cells 120 from each other. The central beam 130 may be inserted between multiple battery cells 120. In some embodiments, the central beam 130 may divide the receiving space 119 into two regions in a second direction (e.g., the Y-axis direction).

[0062] In some embodiments, the crossbeam 116 may be configured to divide the receiving space 119 into two or more regions in a first direction (e.g., the X-axis direction). The crossbeam 116 may additionally isolate elements isolated by the central beam 130.

[0063] Some crossbeams 116 may extend in a second direction (e.g., the Y-axis direction) between the central beam 130 and the first sidewall 111. Other crossbeams 116 may extend in a second direction (e.g., the Y-axis direction) between the central beam 130 and the second sidewall 112. In some embodiments, crossbeams 116 may be provided to define a space for accommodating a battery cell stack or a group of battery cells.

[0064] Figure 1 The arrangement of the central beam 130, crossbeams 116, and multiple battery cells 120 disclosed herein is a non-limiting example and does not limit the technical concept of this disclosure in any way. Those skilled in the art will be able to readily obtain battery packs including a central beam and various arrangements and numbers of battery cells based on the content described herein.

[0065] Multiple venting devices 140 may be coupled to a fourth sidewall 114. The fourth sidewall 114 may include multiple vent holes connected to the multiple venting devices 140. The multiple vent holes may be configured to provide pathways for discharging gases and heat from inside the battery pack 100.

[0066] The multiple venting devices 140 can be configured to delay heat propagation by releasing high-temperature gas inside the battery pack 100 to the outside when at least one of the multiple battery cells 120 is in a thermal runaway state.

[0067] Here, thermal runaway of multiple battery cells 120 is a state in which the temperature changes of multiple battery cells 120 further accelerate the temperature changes, which is an uncontrollable positive feedback. Multiple battery cells 120 in the state of thermal runaway exhibit a rapid temperature rise and can release a large amount of high-pressure gas and combustion residue.

[0068] In some embodiments, a plurality of first recessed guides 151 may be disposed on the sidewall 110S. The plurality of first recessed guides 151 may be disposed on the corner portion 110C of the upper surface of the sidewall 110S. The plurality of first recessed guides 151 may be connected to the corner portion 110C of the upper surface of the sidewall 110S. The plurality of first recessed guides 151 may be partially embedded in the sidewall 110S. The plurality of first recessed guides 151 may partially protrude from the sidewall 110S.

[0069] In some embodiments, a plurality of second recessed guides 153 may be disposed on the sidewall 110S. A plurality of second recessed guides 153 may be disposed on the upper surface of the sidewall 110S. A plurality of second recessed guides 153 may be inserted between the corner portions 110C of the sidewall 110S. A plurality of second recessed guides 153 may be inserted between a plurality of first recessed guides 151. A plurality of second recessed guides 153 may be coupled to the upper surface of the sidewall 110S. A plurality of second recessed guides 153 may be partially embedded in the sidewall 110S. A plurality of second recessed guides 153 may partially protrude from the sidewall 110S.

[0070] In some embodiments, each of the plurality of first recessed guides 151 and the plurality of second recessed guides 153 may include a metallic material. Each of the plurality of first recessed guides 151 and the plurality of second recessed guides 153 may include, for example, aluminum. Each of the plurality of first recessed guides 151 and the plurality of second recessed guides 153 may include, for example, steel, such as carbon steel, nickel steel, chromium steel, nickel-chromium steel, and manganese steel.

[0071] The battery pack 100 may also include electrical components. In some embodiments, the electrical components may be mounted on the lower housing 110. In some embodiments, the electrical components may be disposed between the fourth sidewall 114, where the venting device 140 is mounted, and the plurality of battery cells 120. In some embodiments, the electrical components may include any electronic components required to operate the battery pack.

[0072] In some embodiments, the electrical components may include, for example, a battery management system (BMS). The BMS may be configured to perform monitoring, balancing, and control of 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 the plurality of battery cells 120, and measuring the temperature at a predetermined location within the battery pack 100. In some embodiments, the battery pack 100 may include measuring instruments for measuring the aforementioned voltage, current, and temperature.

[0073] Balancing the battery pack 100 is an operation to reduce deviations between the multiple battery cells 120. Controlling 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, and therefore, can prevent or reduce shortened lifespan of each of the multiple battery cells 120.

[0074] Electrical components may also include cooling devices, power relay assemblies (PRAs), safety plugs, etc. Cooling devices may include cooling fans. The cooling fans prevent overheating of each of the multiple battery cells 120 by circulating air within the battery pack 100. The PRA can be configured to supply power from the high-voltage battery to an external load (e.g., a vehicle motor) or to block power supply. The PRA can protect the multiple battery cells 120 and the external load (e.g., the vehicle motor) by blocking power supply to the external load (e.g., the vehicle motor) in the event of abnormal voltages such as voltage surges.

[0075] The battery pack 100 may also include multiple busbars configured to be electrically connected to multiple battery cells 120. The multiple battery cells 120 may be connected in series and / or in parallel via the multiple busbars. Therefore, the battery pack 100 may be configured to output a high voltage to an external load (e.g., a vehicle motor).

[0076] Gasket 160 may comprise a material that is elastic in response to applied pressure. Gasket 160 may comprise a rubber synthesized from a material such as ethylene-propylene diene monomer (EPDM). When the lower box 110 and the upper box 170 are connected, gasket 160 may be inserted between the lower box 110 and the upper box 170. The lower box 110 and the upper box 170 may press against gasket 160, causing gasket 160 to deform slightly. Therefore, the battery pack 100 can be sealed, and external fluids can be prevented from entering the internal space of the battery pack 100.

[0077] The upper box 170 can be coupled to the lower box 110 to cover the receiving space 119. In some embodiments, the upper box 170 may include a main surface and an edge portion. The main surface may cover components mounted on the battery pack 100, such as multiple battery cells 120 and electrical components. The edge portion is the surface that contacts the lower box 110. In some embodiments, the upper box 170 may be in the form of a plate, in which case the edge portion may horizontally surround the main surface. In some embodiments, the main surface may be raised compared to the edge portion, and the edge portion and the main surface may be connected by a curved portion.

[0078] In some embodiments, the upper box 170 can be connected to the side wall 110S of the lower box 110 via a plurality of first recessed guides 151 and a plurality of second recessed guides 153. According to an exemplary embodiment, the battery pack 100 may further include elements connected to the plurality of first recessed guides 151 and second recessed guides 153 to secure the upper box 170 to the side wall 110S of the lower box 110. These elements may include, but are not limited to, bolts and nuts.

[0079] Figure 3This is an enlarged perspective view of a battery unit 120 installed in a lower housing 110 according to an embodiment of the present disclosure.

[0080] Reference Figure 3 Battery cell stacks (S1, S2, ..., S6) are arranged in each region defined by each sidewall 111, 112, 113, 114 of the lower box 110, the central beam 130, and the crossbeam 116. Each battery cell stack (S1, S2, ..., S6) includes a plurality of battery cells 120. In the following, a battery cell stack may simply refer to a collection of a plurality of battery cells, or may refer to an assembly of a plurality of battery cells housed within a particular frame.

[0081] In some embodiments, the battery cell 120 may be a pouch-type battery cell, but this disclosure is not limited thereto. In some other embodiments, the battery cell 120 may be a prismatic battery cell or a cylindrical battery cell.

[0082] In some embodiments, the pouch cell may have a structure in which a positive electrode, a separator, and a negative electrode are alternately stacked to form an electrode assembly, and electrode tabs are pulled out to at least one side for connection to battery leads. The positive and negative electrodes can be manufactured by applying a slurry of electrode active materials, binder resin, conductive agent, and other additives to at least one surface of the current collector. For the electrode active materials, conventional positive electrode active materials, such as lithium-containing transition metal oxides, can be used for the positive electrode, and conventional negative electrode active materials that intercalate and deintercalate lithium ions, such as lithium metal, carbon materials, and metal compounds or mixtures thereof, can be used for the negative electrode. Furthermore, conventional porous polymer membranes used in lithium secondary batteries can be employed as separators.

[0083] The electrolyte housed within the cover along with the electrode assembly can be a conventional electrolyte used in lithium secondary batteries. The cover is formed of a sheet material and has a receiving portion for accommodating the electrode assembly. Preferably, the cover is formed by combining a first box and a second box, which are formed by processing the sheet material into a predetermined shape. The sheet material forming the cover has a multilayer structure, in which stacked layers are an outer resin layer made of an insulating material such as polyethylene terephthalate (PET) or nylon, a metal layer made of an aluminum material 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 thermal adhesion and serves as a sealing material.

[0084] Depending on the requirements, the sheet material forming the cover may have predetermined adhesive resin layers inserted between the inner resin layer and the metal layer, and between the outer resin layer and the metal layer. The adhesive resin layers are used for smooth bonding between different materials and are formed as a single layer or multiple layers. The materials are typically polyolefin-based resins or polyurethane resins used for smoothing, or mixtures thereof may be used.

[0085] Multiple battery cells 120 may be arranged along a first direction (e.g., the X-axis direction). In some embodiments, a first battery cell stack (S1), a second battery cell stack (S2), and a third battery cell stack (S3) may be arranged along the first direction (e.g., the X-axis direction). In some embodiments, a fourth battery cell stack (S4), a fifth battery cell stack (S5), and a sixth battery cell stack (S6) may be arranged along the first direction (e.g., the X-axis direction).

[0086] In some embodiments, the first battery cell stack (S1) and the fourth battery cell stack (S4) may be arranged along 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) may be arranged along 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) may be arranged along a second direction (e.g., the Y-axis direction).

[0087] Figure 4 The illustration shows an exploded perspective view of a thermal barrier pad 180 according to an embodiment of the present disclosure.

[0088] Reference Figures 1 to 4 The battery pack 100 may also include a thermal barrier pad 180. The thermal barrier pad 180 may absorb heat generated from the battery cell 120 and / or block or delay the transfer of heat.

[0089] The thermal barrier pad 180 may include a porous heat-absorbing material 180p and a heat-absorbing solution composition absorbed in the heat-absorbing material 180p.

[0090] In some embodiments, the endothermic solution composition may include about 0.20 wt.% to about 0.45 wt.% of a surfactant; about 0.3 wt.% to about 5.0 wt.% of a thickener; and about 60 wt.% to about 80 wt.% of water.

[0091] <surfactants>

[0092] In some embodiments, the surfactant may include cationic surfactants, anionic surfactants, nonionic surfactants, amphoteric surfactants, fluoro-based surfactants, or silicone-based surfactants.

[0093] Cationic surfactants can include alkylamine salts, amine salts such as polyamines and amino alcohol fatty acid derivatives, alkyl quaternary ammonium salts, aromatic quaternary ammonium salts, pyridine salts, or imidazole salts.

[0094] Anionic surfactants may include fatty acid soaps such as sodium stearate or triethanolamine palmitate, alkyl ether carboxylic acids and their salts, condensed salts of amino acids and fatty acids, alkane sulfonates, olefin sulfonates, sulfonates of fatty acid esters, sulfonates of fatty acid amides, formalin condensed 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 alkanolamides, sulfate salts such as rosin oil, alkyl phosphates, ether phosphates, alkyl allyl ether phosphates, amide phosphates, N-acyl lactates, N-acyl sarcosine salts, or N-acyl amino acid-based surfactants.

[0095] As nonionic surfactants, glycerol, trimethylolpropane, trimethylolethane and their ethoxylated and propoxylated derivatives (e.g., glycerol propoxylated, glycerol ethoxylated, etc.), polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oil-based ether, polyoxyethylene octylphenyl ether, polyoxyethylene nonylphenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, sorbitan fatty acid ester, glycerol fatty acid ester, polyglycerol 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, polyoxyethylene Alkyl phenyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene glycerol fatty acid esters, polyoxyethylene propylene glycol fatty acid esters, polyoxyethylene castor oil, polyoxyethylene hydrogenated castor oil, polyoxyethylene phytosterol ethers, polyoxyethylene cholesterol ethers, polyoxyethylene cholesterol ethers, linear or branched polyoxyethylene modified organopolysiloxanes, linear or branched polyoxyethylene alkyl co-modified organopolysiloxanes, linear or branched polyglycerol modified organopolysiloxanes, linear or branched polyglycerol alkyl co-modified organopolysiloxanes, alkanolamides, sugar ethers, sugar amides, etc.

[0096] As amphoteric surfactants, betaine, aminocarboxylate, imidazoline derivatives, and amide-amine types can be mentioned.

[0097] Fluoropolymer surfactants can be polymers of vinyl ether compounds and hydrophilic vinyl ether compounds having fluorinated alkyl or fluorinated alkylene ether groups. Block polymers can also be used as fluoropolymer surfactants. Fluoropolymers comprising repeating units derived from (meth)acrylate compounds having fluorinated atoms and repeating units derived from (meth)acrylate compounds having two or more (preferably five or more) alkylene oxides (preferably ethylene oxide, propylene oxide) can also be used as fluoropolymer surfactants.

[0098] Among commercially available fluoropolymer surfactants, DIC's MEGAFACE® product line can be mentioned: 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, and F-5 61, 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's Fluorosur... The Factant® product line includes FC-135, FC-170C, FC-430, FC-431, FC-4430, and FC-4433; AGC's SURFLON® product line includes S-211, S-221, S-231, S-232, S-241, S-242, S-243, S-420, S-431, S-386, S-611, and S-647. -651, S-653, S-656, S-658, F693; DuPont's CAPSTONE® product line 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, FS-83, etc., but not limited to these.

[0099] Silicon-based surfactants include DOWSIL SH8400, SH8400 FLUID, FZ-2122, 67 Additive, 74 Additive, M Additive, SF 8419 OIL (all manufactured by Dow Toray Ltd.), TSF-4300, TSF-4445, TSF-4460, TSF-4452 (all manufactured by Momentive Performance Materials Ltd.), KP-341, KF-6000, KF-6001, KF-6002, KF-6003 (all manufactured by Shin-Etsu Chemical Ltd.). 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-34 8. 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 (all manufactured by BYK-Chemie), DYNOL 360, DYNOL 604, DYNOL 607, DYNOL 800, DYNOL 810, and possibly TEGO's Twin4000, Twin 4100, and Twin 4200 (all manufactured by Evonik), are mentioned, but are not limited to these. In some embodiments, the silicone-based surfactant may include polydimethylsiloxane (PDMS).

[0100] The endothermic solution composition may include about 0.20 wt.% to about 0.45 wt.% of a surfactant. In some embodiments, the endothermic solution composition may include about 0.20 wt.% to about 0.45 wt.%, about 0.21 wt.% to about 0.44 wt.%, about 0.22 wt.% to about 0.43 wt.%, about 0.23 wt.% to about 0.42 wt.%, about 0.24 wt.% to about 0.41 wt.%, about 0.25 wt.% to about 0.40 wt.%, about 0.26 wt.% to about 0.39 wt.%, about 0.27 wt.% to about 0.38 wt.%, about 0.28 wt.% to about 0.37 wt.%, about 0.29 wt.% to about 0.36 wt.%, about 0.30 wt.% to about 0.35 wt.%, about 0.31 wt.% to about 0.34 wt.%, about 0.32 wt.% to about 0.33 wt.%. A wt.% amount of surfactant, or a range between any two of these values.

[0101] When the content of surfactant included in the endothermic solution composition is too low, the endothermic performance of the endothermic solution composition may be insufficient. When the content of surfactant included in the endothermic solution composition is too high, the endothermic performance of the endothermic solution composition may be saturated, and this is economically disadvantageous.

[0102] Thickener

[0103] 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.

[0104] The endothermic solution composition may include about 0.3 wt.% to about 5.0 wt.% of a thickener. In some embodiments, the endothermic solution composition may include about 0.5 wt.% to about 3.0 wt.% of a thickener. In some embodiments, the endothermic solution composition may include about 1 wt.% to about 2.2 wt.% of a thickener. In some embodiments, the endothermic solution composition may include about 0.3 wt.% to about 5.0 wt.%, about 0.4 wt.% to about 4.5 wt.%, about 0.5 wt.% to about 4.0 wt.%, about 0.6 wt.% to about 3.5 wt.%, about 0.7 wt.% to about 3.0 wt.%, about 0.8 wt.% to about 2.5 wt.%, about 0.9 wt.% to about 2.0 wt.%, about 1 wt.% to about 1.5 wt.%, or a thickener in the range of any two of these values.

[0105] When the amount of thickener included in the endothermic solution composition is too low, the endothermic solution composition may leak. When the amount of thickener included in the endothermic solution composition is too high, the productivity of the endothermic solution composition may decrease.

[0106] In some embodiments, the endothermic solution composition may also include an antifreeze agent. The antifreeze agent may include, for example, salts such as CaCl2, NaCl, potassium acetate, or potassium formate; or short-chain alcohols or glycols such as isopropanol, butyl diethylene glycol, ethylene glycol, diethylene glycol, dipropylene glycol, or propylene glycol; and may also include urea or glycerol.

[0107] The endothermic solution composition may include about 15 wt.% to about 35 wt.% of antifreeze. In some embodiments, the endothermic solution composition may include about 20 wt.% to about 30 wt.% of antifreeze.

[0108] In some embodiments, the endothermic solution composition may include an amount of antifreeze in the range of about 15 wt.% to about 35 wt.%, about 16 wt.% to about 34 wt.%, about 17 wt.% to about 33 wt.%, about 18 wt.% to about 32 wt.%, about 19 wt.% to about 31 wt.%, about 20 wt.% to about 30 wt.%, about 21 wt.% to about 29 wt.%, about 22 wt.% to about 28 wt.%, about 23 wt.% to about 27 wt.%, about 24 wt.% to about 26 wt.%, or any two of these values.

[0109] When the amount of antifreeze included in the endothermic solution composition is too low, the endothermic solution composition may freeze easily at low temperatures. When the amount of antifreeze included in the endothermic solution composition is too high, the endothermic performance of the endothermic solution composition may decrease.

[0110] In some embodiments, the endothermic solution composition may include about 60 wt.% to about 80 wt.% water. In some embodiments, the endothermic solution composition may include an amount of water in the range of about 60 wt.% to about 80 wt.%, about 61 wt.% to about 79 wt.%, about 62 wt.% to about 78 wt.%, about 63 wt.% to about 77 wt.%, about 64 wt.% to about 76 wt.%, about 65 wt.% to about 75 wt.%, about 66 wt.% to about 74 wt.%, about 67 wt.% to about 73 wt.%, about 68 wt.% to about 72 wt.%, about 69 wt.% to about 71 wt.%, or any amount of water within any two of these values.

[0111] When the water content in the endothermic solution composition is too low, the endothermic performance of the composition may decrease. When the water content in the endothermic solution composition is too high, the endothermic duration of the composition may be shortened.

[0112] In some embodiments, the thermal barrier pad 180 may be disposed on top of the battery cell 120. In some embodiments, the thermal barrier pad 180 may be disposed between the upper housing 170 and the battery cell 120. Hereinafter, the thermal barrier pad disposed between the upper housing 170 and the battery cell 120 may be referred to as the first thermal barrier pad 180.

[0113] The first thermal barrier pad 180 may have a predetermined area along a plane perpendicular to a third direction (e.g., the Z-axis direction). The first thermal barrier pad 180 may include a heat dissipation bag 180c having an internal space. The heat dissipation bag 180c may form the appearance of the first thermal barrier pad 180. In some embodiments, the first thermal barrier pad 180 may include a heat-absorbing material 180p and a heat-absorbing solution composition disposed in the internal space of the heat dissipation bag 180c. The heat dissipation bag 180c includes a substantially parallel first layer 180a and a second layer 180b, and the internal space may be defined between the first layer 180a and the second layer 180b.

[0114] The heat dissipation bag 180c may consist of a single layer or may be a laminate composed of two or more stacked layers. In some embodiments, the heat dissipation bag 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 bag 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 bag 180c may include an inner resin layer made of a polyolefin-based material that has thermal adhesion and serves as a sealing material.

[0115] Although for ease of explanation, the outer surface of the heat sink 180c is... Figure 4 The image shows a completely flat surface, but the heat sink 180c may not be completely flat due to deformation caused by external forces, and may be at least partially deformed due to external forces.

[0116] The endothermic solution composition can be absorbed in the heat-absorbing insulating material 180p, and may include a material that can undergo a phase change according to temperature changes. The heat dissipation bag 180c can be configured to deform according to the phase change of the endothermic solution composition.

[0117] In some embodiments, the heat-absorbing material 180p may include a porous insulating material. The porous insulating material may be, for example, glass fiber or quartz fiber. In some embodiments, the heat-absorbing material 180p may include a nonwoven fabric with glass fiber or silica fiber as the main component. Here, "main component" means that the corresponding component contains more than 50% of the total weight.

[0118] In some embodiments, the heat-absorbing material 180p may include a superabsorbent polymer (SAP), such as a superabsorbent polymer. The superabsorbent polymer can be any material known in the art and is not particularly limited thereto. In some embodiments, the superabsorbent polymer may include polyacrylamide, polyacrylic acid, polymethacrylic acid, polyethylene oxide, polyvinyl alcohol, gelatin, polysaccharides, chitosan, sodium carboxymethyl cellulose, or combinations thereof, but this disclosure is not limited thereto. In some embodiments, the heat-absorbing material 180p may be in the form of powder, granules, small particles, flakes, sheets, etc., and is not particularly limited thereto.

[0119] The liquid endothermic solution composition can be absorbed in the heat-absorbing insulating material 180p. In some embodiments, the endothermic solution composition may include materials capable of repeated evaporation and condensation within the operating temperature range of the battery cell 120 and a pressure range near atmospheric pressure. For example, the endothermic solution composition may include materials capable of evaporation or condensation within a pressure range of about 1 atmosphere to about 10 atmospheres and a temperature range of about 70°C to about 130°C.

[0120] The heat-absorbing solution composition can be evaporated by heat transferred from the battery cell 120 through the second layer 180b of the heat dissipation bag 180c. The evaporated heat-absorbing material can exist in a gaseous state within the heat dissipation bag 180c, and then condense and liquefy as the heat dissipation bag 180c cools, and can be reabsorbed into the heat-absorbing insulating material 180p. Because the heat transferred from the battery cell 120 is used for the temperature rise and heat of vaporization of the heat-absorbing material, heat transfer to adjacent other battery cells 120 can be reduced or prevented.

[0121] In some embodiments, the first thermal barrier pad 180 may have a bonding portion 180m. In some embodiments, the bonding portion 180m may be a portion formed by fusing opposing laminated 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, in the event of an internal thermal event, the bonding portion 180m is opened or a specific location of the bonding portion 180m is opened.

[0122] like Figure 1 and Figure 4As shown, when the first thermal barrier pad 180 is disposed between the upper surface of the battery cell 120 and the upper box 170, even if a thermal event occurs in a particular battery cell 120, the flame energy can be effectively weakened, and the damage to the upper box 170 caused by heat can be mitigated or prevented.

[0123] Figure 5 This is a perspective view of a thermal barrier pad 181 according to an embodiment of the present disclosure. Figure 6 The illustration shows a schematic side cross-section of a thermal barrier pad 181 inserted between battery cells 120.

[0124] Figure 6 The side view cross section shown can be, for example, along... Figure 3 The cross section cut by line VI-VI'.

[0125] Reference Figure 5 and Figure 6 The thermal barrier pad 181 may have a form that extends generally along 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 along the second direction (e.g., the Y-axis direction) and may directly contact the side surface of the adjacent battery cell 120. Hereinafter, the thermal barrier pad disposed on the side surface of the battery cell 120 may be referred to as the second thermal barrier pad 181.

[0126] The second thermal barrier pad 181 may have a predetermined area along a plane perpendicular to the first direction (e.g., the X-axis direction). In some embodiments, the second thermal barrier pad 181 may be inserted between a pair of battery cells 120. A first side surface 181a forming one side of the second thermal barrier pad 181 may directly contact one of the battery cells 120 in the pair. Furthermore, a second side surface 181b forming the other side of the second thermal barrier pad 181 may directly contact the other battery cell 120 in the pair.

[0127] In some embodiments, the second thermal barrier pad 181 may be thermally connected to the lower housing 110 and may transfer heat received from the battery cell 120 to the plate component 110P. In some embodiments, the second thermal barrier pad 181 may be thermally connected to the upper housing 170 (see Figure 170). Figure 1 Here, the fact that the second thermal barrier pad 181 is "thermally connected" to an object may mean that most of the heat released from the second thermal barrier pad 181 is removed through that object; for example, it may mean that more than 50% of the heat released from the second thermal barrier pad 181 is removed through that object.

[0128] In some embodiments, the plate component 110P of the lower housing 110 may include a heat sink 110FP. For example, the heat sink 110FP may include flow paths configured to allow cooling fluid to flow internally. Therefore, heat transferred to the lower plate component 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 housing 110 than to the upper housing 170.

[0129] In some embodiments, the second thermal barrier pad 181 may be arranged alternately with the battery cells 120 one after another. In some embodiments, a second thermal barrier pad 181 may be provided for every two or more battery cells 120. That is, two or more battery cells 120 may be positioned between two closest adjacent second thermal barrier pads 181.

[0130] In some embodiments, the second thermal barrier pad 181 may be disposed at both ends of a plurality of battery cells 120 located in a compartment space 119d in a first direction (e.g., the X-axis direction). In this case, thermal events occurring in one compartment space 119d can be effectively prevented or delayed from being transmitted to another adjacent compartment space 119d. In this case, the second thermal barrier pad 181 may be arranged to face directly toward the crossbeam 116.

[0131] In some embodiments, two battery cells 120 may be disposed between two closest adjacent second thermal barrier pads 181. In this case, since at least one side surface of any battery cell 120 is in contact with the second thermal barrier pad 181, heat transfer to adjacent battery cells 120 can be minimized even if a thermal event occurs in a battery cell 120.

[0132] Figure 7 yes Figure 5 The figure shows a front view of a second thermal barrier pad 181 according to an embodiment of the present disclosure. Figure 8 It is illustrated along Figure 7 A cross-sectional view of the second thermal barrier pad 181 cut by line VIII-VIII'.

[0133] Reference Figure 7 and Figure 8 The second thermal barrier pad 181 has a porous heat-absorbing material 180p, which has a first main surface 181p1 and a second main surface 181p2. The heat-absorbing solution composition is absorbed in the heat-absorbing material 180p. The first main surface 181p1 and the second main surface 181p2 can be substantially parallel to each other.

[0134] A heat-conducting sheet 182 may be provided on at least one of the first main surface 181p1 and the second main surface 181p2 of the heat-absorbing material 180p.

[0135] The heat-conducting plate 182 may include a metallic material with excellent thermal conductivity. In some embodiments, the heat-conducting plate 182 may include copper (Cu), aluminum (Al), zinc (Zn), tin (Sn), iron (Fe), or alloys thereof.

[0136] In some embodiments, the heat-conducting sheet 182 may have a thickness of about 5 μm to about 50 μm. In some embodiments, the heat-conducting sheet 182 may have a thickness 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 a thickness within any two of these values.

[0137] If the heatsink 182 is too thin, its mechanical strength may be insufficient, and manufacturing may be difficult. If the heatsink 182 is too thick, the product weight may increase excessively, and manufacturing costs may rise.

[0138] In some embodiments, the heat-conducting sheet 182 may be disposed on the first main surface 181p1 of the heat-insulating and absorbing material 180p. In some other embodiments, the heat-conducting sheet 182 may be disposed on the first main surface 181p1 and the second main surface 181p2 of the heat-insulating and absorbing material 180p, respectively, such as... Figure 8 As shown in the image.

[0139] In some embodiments, the heat-conducting sheet 182 may be configured to substantially cover the entire surface of the first main surface 181p1 and / or the second main surface 181p2. In some other embodiments, the heat-conducting sheet 182 may be configured to cover a portion of the surface of the first main surface 181p1 and / or the second main surface 181p2.

[0140] In some embodiments, the heat-conducting plate 182 may be in the form of a plate. In some other embodiments, the heat-conducting plate 182 may be in the form of a mesh. In some embodiments, the heat-conducting plate 182 may be in the form of a plate with holes.

[0141] The heat dissipation bag 180c can be configured to surround the heat-absorbing material 180p and the heat-conducting plate 182. The heat dissipation bag 180c has facing joint portions 181m on the outside of the heat-absorbing material 180p. In some embodiments, the joint portions 181m can be thermally fused to seal the heat-absorbing material 180p and the heat-conducting plate 182 from the outside.

[0142] A free space 181f can be provided on one side of the heat-absorbing material 180p within the heat dissipation bag 180c. The free space 181f can accommodate some components of the heat-absorbing solution composition that evaporates from the heat-absorbing material 180p through heat absorption. The free space 181f can be positioned between the heat-absorbing material 180p and the connecting portion 181m. Figure 7 In the diagram, free space 181f is shown only on the lateral side of the heat-absorbing material 180p, but this disclosure is not limited thereto. In some embodiments, based on Figure 7 In the arrangement structure, the free space 181f can also be located on the upper side of the heat-absorbing material 180p.

[0143] The configuration and effects of this disclosure will be described in more detail below with specific and comparative examples, but these examples are only for the purpose of making a clearer understanding of this disclosure and not for limiting the scope of this disclosure.

[0144] <Comparison Example 1>

[0145] A polyacrylonitrile-based superabsorbent polymer in plate form is used as the heat-absorbing material. After water, which is an endothermic solution composition, is absorbed into the heat-absorbing material, copper foil with a thickness of 0.01 mm is placed on both sides of the heat-absorbing material as a heat-conducting sheet.

[0146] After the heat-absorbing material and the thermally conductive sheet are surrounded by the heat-dissipating bag 180c, a thermal barrier pad is manufactured by heat fusion sealing. For the heat-dissipating bag 180c, a conventional laminate that includes an aluminum layer and is used when manufacturing pouch-type battery cells is used.

[0147] <Example 1>

[0148] Except that the endothermic solution composition includes 0.5 wt.% CMC as a thickener and 0.25 wt.% PDMS as a surfactant, the heat insulation pad is manufactured in the same manner as in Comparative Example 1.

[0149] <Example 2>

[0150] The thermal barrier pad was manufactured in the same manner as in Comparative Example 1, except that the endothermic solution composition included 1 wt.% CMC as a thickener and 0.25 wt.% PDMS as a surfactant.

[0151] <Example 3>

[0152] The thermal barrier pad was manufactured in the same manner as in Comparative Example 1, except that the endothermic solution composition included 2 wt.% CMC as a thickener and 0.25 wt.% PDMS as a surfactant.

[0153] <Example 4>

[0154] Except that the endothermic solution composition includes 1 wt.% CMC as a thickener, 0.3 wt.% PDMS as a surfactant and 25 wt.% CaCl2 as an antifreeze, the thermal barrier pad is manufactured in the same manner as in Comparative Example 1.

[0155] The temperature change over time of the thermal barrier pads manufactured in Comparative Example 1 and Examples 1 to 4 was measured while the pads were heated with a blowtorch through a stainless steel plate inserted on one side of the thermal barrier pad. The temperature of the thermal barrier pad was measured by inserting a thermocouple between the thermal barrier pad and the stainless steel plate.

[0156] Figure 9 It is a graph depicting the temperature change over time for the thermal barrier pads of Comparative Example 1 and Examples 1 to 4, respectively.

[0157] Reference Figure 9 The thermal barrier pad in Comparative Example 1 maintained a surface temperature of 100°C and then showed a rapid temperature rise at a point slightly over 150 seconds.

[0158] Meanwhile, the thermal barrier pads of Examples 1 to 3 maintained a surface temperature of 100°C and then exhibited a rapid temperature rise at a point exceeding 240 to 280 seconds. Therefore, it can be seen that the thermal barrier pads of Examples 1 to 3 have superior heat absorption and insulation properties compared to the thermal barrier pad of Comparative Example 1.

[0159] Furthermore, the thermal barrier pad of Example 4 maintained a surface temperature of 100°C, and then gradually increased in temperature at a point exceeding approximately 300 seconds, and was observed to remain at 150°C or lower even up to 500 seconds. That is, compared with the thermal barrier pad of Comparative Example 1 and the thermal barrier pads of Examples 1 to 3, the thermal barrier pad of Example 4 was observed to have superior heat absorption and insulation properties.

[0160] <Example 5>

[0161] Except that the endothermic solution composition includes 1 wt.% CMC as a thickener, 0.3 wt.% PDMS as a surfactant and 20 wt.% CaCl2 as an antifreeze, the thermal barrier pad is manufactured in the same manner as in Comparative Example 1.

[0162] <Example 6>

[0163] Except that the endothermic solution composition includes 1 wt.% CMC as a thickener, 0.3 wt.% PDMS as a surfactant and 15 wt.% CaCl2 as an antifreeze, the thermal barrier pad is manufactured in the same manner as in Comparative Example 1.

[0164] <Example 7>

[0165] Except that the endothermic solution composition includes 1 wt.% CMC as a thickener, 0.3 wt.% PDMS as a surfactant and 10 wt.% CaCl2 as an antifreeze, the thermal barrier pad is manufactured in the same manner as in Comparative Example 1.

[0166] <Example 8>

[0167] Except that the endothermic solution composition includes 2 wt.% CMC as a thickener, 0.25 wt.% PDMS as a surfactant and 15 wt.% CaCl2 as an antifreeze, the thermal barrier pad is manufactured in the same manner as in Comparative Example 1.

[0168] <Example 9>

[0169] Except that the endothermic solution composition includes 2.5 wt.% CMC as a thickener, 0.25 wt.% PDMS as a surfactant and 15 wt.% CaCl2 as an antifreeze, the thermal barrier pad is manufactured in the same manner as in Comparative Example 1.

[0170] <Comparison Example 2>

[0171] Except that the endothermic solution composition includes 0.2 wt.% CMC as a thickener and 0.25 wt.% PDMS as a surfactant, the thermal barrier pad is manufactured in the same manner as in Comparative Example 1.

[0172] <Comparison Example 3>

[0173] Except that the endothermic solution composition includes 8 wt.% CMC as a thickener, 0.3 wt.% PDMS as a surfactant and 10 wt.% CaCl2 as an antifreeze, the thermal barrier pad is manufactured in the same manner as in Comparative Example 1.

[0174] <Comparison Example 4>

[0175] The thermal barrier pad was manufactured in the same manner as in Comparative Example 1, except that the endothermic solution composition included 1 wt.% CMC as a thickener and 0.1 wt.% PDMS as a surfactant.

[0176] <Comparison Example 5>

[0177] The thermal barrier pad was manufactured in the same manner as in Comparative Example 1, except that the endothermic solution composition included 2 wt.% CMC as a thickener and 0.5 wt.% PDMS as a surfactant.

[0178] The heat absorption duration was measured for each thermal barrier pad manufactured in Examples 1 to 9 and Comparative Examples 1 to 5. The heat absorption duration was defined as the time interval between the point when the temperature on one side of the thermal barrier pad reaches 100°C and the point when the temperature on one side of the thermal barrier pad reaches 150°C.

[0179] To raise the temperature of the thermal barrier pads manufactured in Examples 1 to 9 and Comparative Examples 1 to 5, a blowtorch was used to heat the pads through a stainless steel plate inserted on one side of the thermal barrier pads. The temperature of the thermal barrier pads was measured by inserting a thermocouple between the thermal barrier pads and the stainless steel plate.

[0180] Table 1 summarizes the endothermic durations measured as described above.

[0181] Table 1

[0182]

[0183] When the thickener is not included (Comparative Example 1) or is included in too small an amount (Comparative Example 2), leakage of the endothermic solution composition is observed.

[0184] When an excessive amount of thickener was included (Comparative Example 3), no leakage of the endothermic solution composition was observed. Furthermore, the endothermic duration was not significantly improved in this case. Although this disclosure is not limited to any particular theory, it should be understood that when the thickener content is excessive, the tension formed at the interface between the endothermic solution composition and the heat-absorbing material increases excessively, thereby limiting the heat absorption and insulation performance of the thermal barrier pad.

[0185] Even when the surfactant content is too low (Comparative Example 4), the endothermic duration is not improved. Although this disclosure is not limited to any particular theory, this is also thought to be due to excessive tension at the interface between the endothermic solution composition and the heat-absorbing material caused by the low surfactant content.

[0186] Even when the surfactant concentration was too high (Comparative Example 5), the endothermic duration was not improved. Comparative Examples 3 and 5 had surfactant concentrations of 0.25 wt.% and 0.5 wt.%, respectively, with other conditions almost identical. The fact that the endothermic duration of Example 3 was significantly longer than that of Comparative Example 5 suggests the existence of an optimal surfactant concentration range.

[0187] Figure 10 This is a perspective view of a battery pack 100a according to another embodiment of the present disclosure. Figure 10 The battery pack 100a of the embodiment shown in the figure and Figure 1The difference in the battery pack 100 shown lies in the size and number of thermal barrier pads 180. Therefore, the following description will focus on these differences and omit descriptions of repetitive parts.

[0188] Reference Figure 10 A thermal barrier pad 180 can correspond to each battery cell stack (S1, S2, ..., S6). In this case, for each compartment space 119d (refer to...) Figure 2 As for [the type of component], damaged parts can be replaced, so maintenance can be easy.

[0189] Figure 11 This is an exploded perspective view of a battery module 120M according to an embodiment of the present disclosure. Figure 12 This is a perspective view of a battery module 120M according to an embodiment of the present disclosure.

[0190] Reference Figure 11 and Figure 12 The battery module 120M may include a battery unit 120, module boxes 122 and 123 that house the battery unit 120, and end plates 124 and 125 connected to the front and rear surfaces of the module boxes 122 and 123.

[0191] In some embodiments, the battery cell 120 may be, for example, a plurality of stacked pouch-type battery cells 120a. In some embodiments, the battery cell 120 may be a plurality of stacked prismatic battery cells.

[0192] In some embodiments, the second thermal barrier pad 181 may be disposed at both ends of the battery cell 120 in a first direction (X-axis direction). Since reference has already been made... Figure 5 and Figure 6 The specific configuration of the second thermal barrier pad 181 has been described, so further details will be omitted here. In some embodiments, the second thermal barrier pad 181 may also be disposed between multiple battery cells 120.

[0193] In some embodiments, module boxes 122 and 123 may include a lower box 122 and an upper box 123. Figure 11 In the diagram, a U-shaped frame with two side plates 122b and a base plate 122a is shown as the lower box 122, but those skilled in the art will understand that other forms of the lower box 122 can be applied. The forms of the module boxes 122 and 123 are not limited to those shown in the diagram. Figure 11 The form disclosed herein can be used, and other forms of module boxes can be applied, as long as they can stably accommodate the battery unit 120.

[0194] The busbar frame (BFA) can be attached to the front and rear surfaces of the battery cell 120. Busbars (B) for connecting the electrode leads of the battery cell and busbars B for electrical connection to other battery modules or external components can be installed in the busbar frame (BFA).

[0195] In some embodiments, a front plate 124 and a rear plate 125 for protecting the busbar frame BFA and the battery cell 120 may be located on the front and rear surfaces of the battery cell 120. The front plate 124 and the rear plate 125 may be connected to module boxes 122, 123 and / or the busbar frame BFA.

[0196] In some embodiments, module boxes 122 and 123 may have vent holes H for venting gas from within the module. In some embodiments, the upper box 123 may have vent holes H.

[0197] A TIM layer 122t comprising thermoplastic resin can be provided on the base plate 122a of the lower box 122. The TIM layer 122t on the base plate 122a can fix the battery unit 120 to the base plate 122a. In addition, the TIM layer 122t can transfer heat generated from the battery unit 120 to the base plate 122a of the lower box 122.

[0198] In some embodiments, an additional TIM layer (not shown) may be further provided on the inner surface of the upper box 123. That is, the additional TIM layer may be provided between the upper box 123 and the upper surface of the battery unit 120.

[0199] Battery cells 120 are mounted on the lower box 122 of the U-shaped frame, and the upper box 123 is connected to the lower box 122 by welding or the like, so that the battery cells 120 can be accommodated within the module boxes 122 and 123. In some embodiments, at least one second thermal barrier pad 181 may be disposed between the battery cells 120. The second thermal barrier pad 181 may be disposed at both ends of the battery cells 120 accommodated in the module boxes 122 and 123 in a first direction (e.g., the X-axis direction). In this case, the second thermal barrier pad 181 may directly contact the side plate 122b of the lower box 122.

[0200] The front-end plate 124 and the rear-end plate 125 are connected to the busbar frame BFA inserted between the front and rear surfaces of the battery cell 120, thereby completing the following... Figure 12 The battery module shown. Heat transferred to the thermal barrier structure 128 can be transferred to the housing 101 via the lower box 122 and / or the upper box 123.

[0201] In some embodiments, at least one of the upper box 123 and the lower box 122 may be equipped with a cooling device. In some embodiments, the upper box 123 may include two plates connected with a gap, and a cooling channel may be provided in the gap portion. In some embodiments, the bottom plate 122a may include two plates connected with a gap, and a cooling channel may be provided in the gap portion.

[0202] In some embodiments, the battery module 120M may have a connecting member F2 for connecting to a corresponding structure within the battery pack 100. In some embodiments, the connecting member F2 with a fastening hole h2 may be disposed on both sides of the end plates 124, 125 of the battery module 120M for connecting to a structure for supporting the battery module 120M.

[0203] Multiple battery modules 120M can be installed within the battery pack 100.

[0204] As in Figure 11 and Figure 12 In the battery module 120M shown, when the lower box 122 is equipped with a TIM layer 122t, the bottom plate 122a side of the lower box 122 can be connected to the plate component 110P of the lower box 110 of the battery pack 100. In some embodiments, a thermal barrier pad 180 can be provided instead of the TIM layer 122t.

[0205] Since the second thermal barrier pad 181 is disposed at both ends of the battery cell 120 housed in the module boxes 122, 123, it can effectively prevent or delay the transmission of thermal events occurring in a particular battery module 120M to other adjacent battery modules 120M.

[0206] Figure 13 The illustration is a schematic side view of an electrified vehicle 10 according to an embodiment of the present disclosure. Figure 14 It is a conceptual illustration of a battery pack 100 and other components installed in an electrified vehicle 10.

[0207] Reference Figure 13 and Figure 14 The electrified vehicle 10 according to embodiments of the present disclosure may include at least one or more battery packs 100. The electrified vehicle 10 may include, for example, a vehicle body having a housing space for at least accommodating the battery packs 100. For example, the electrified vehicle 10 may be a battery electric vehicle (BEV), a plug-in hybrid electric vehicle (PHEV), or a full hybrid electric vehicle (FHEV).

[0208] The electrified vehicle 10 may include one or more motors 214 mechanically coupled to one or more gearboxes or hybrid transmissions 216. The motors 214 may operate as motors or generators. Furthermore, when the electrified vehicle 10 is a PHEV or FHEV, it may include an engine 218, and the hybrid transmission 216 may be mechanically coupled to the engine 218.

[0209] Furthermore, the hybrid transmission 216 can be mechanically coupled to the drive shaft 220, which in turn is mechanically coupled to the wheels 222. The electric motor 214 can propel or decelerate depending on whether the engine 218 is on or off, or it can act as a generator to recover energy. The electric motor 214 enables the engine 218 to operate at a more efficient speed to reduce emissions and allows the electrified vehicle 10 to shut down the engine 218 and operate in electric mode under certain conditions. When the electrified vehicle 10 is a battery electric vehicle (BEV), the engine 218 is omitted.

[0210] The battery pack 100 stores the energy used by the motor 214, and has been referenced Figures 1 to 12 The description has already been provided, so redundant descriptions will be omitted. Battery pack 100 can provide a high-voltage direct current (DC) output. Contactor module 242 may include one or more contactors configured to disconnect battery pack 100 from high-voltage bus 252 when open and connect battery pack 100 to high-voltage bus 252 when closed.

[0211] One or more inverters 226 may be electrically connected to the high-voltage bus 252. Inverters 226 are also connected to the motor 214 and can transfer energy bidirectionally between the battery pack 100 and the motor 214. For example, when the motor 214 is operating on three-phase AC power, the battery pack 100 can provide DC voltage. Inverters 226 can convert the DC voltage into three-phase AC current to power the motor 214. In regenerative mode, inverters 226 can convert the three-phase AC current from the motor 214 into DC voltage suitable for the battery pack 100.

[0212] In some embodiments, battery pack 100 can provide energy to other electrical systems of the vehicle in addition to the energy used for vehicle propulsion. The electrified vehicle 10 may include a DC / DC converter module 228, which converts a high-voltage DC output from high-voltage bus 252 into a low-voltage DC level on low-voltage bus 254 compatible with low-voltage load 256. The output of DC / DC converter module 228 may be electrically connected to auxiliary battery 230 (e.g., a 12V battery) to charge auxiliary battery 230. Low-voltage load 256 may be electrically connected to auxiliary battery 230 via low-voltage bus 254. One or more high-voltage loads 246 may be connected to high-voltage bus 252. High-voltage loads 246 may be, for example, fans, electric heating elements, and / or air conditioning compressors.

[0213] The electrified vehicle 10 can be configured to recharge the battery pack 100 using an external power source 236. In some embodiments, the external power source 236 may be electrically connected to an electric vehicle power supply device (EVSE) 238. The external power source 236 may supply DC or AC power to the EVSE 238, and the EVSE 238 may include circuitry for managing and controlling the energy transfer between the external power source 236 and the electrified vehicle 10.

[0214] EVSE 238 may include a charging connector 240, which can be connected to a charging port 234 of the electrified vehicle 10. The charging port 234 can be any port capable of transmitting power from EVSE 238 to the electrified 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 EVSE 238 and converts the power into voltage and current levels suitable for the battery pack 100.

[0215] In some implementations, battery pack 100 may be electrically connected to auxiliary battery 230. Auxiliary battery 230 may be configured to supply the power necessary to perform some functions of battery pack 100.

[0216] All functions of the aforementioned electrified vehicle 10 can be controlled by the system controller 248.

[0217] As described above, although embodiments of the present disclosure have been described in detail, those skilled in the art will be able to implement the present disclosure with various modifications without departing from the spirit and scope of the present disclosure as defined in the appended claims. Therefore, further modifications to embodiments of the present disclosure will not depart from the technology of the present disclosure.

Claims

1. A thermal barrier pad, comprising: A porous heat-absorbing material, the heat-absorbing material having a first main surface and a second main surface; An endothermic solution composition, wherein the endothermic solution composition is absorbed in the heat-absorbing insulating material; A thermally conductive sheet, the thermally conductive sheet covering at least one of the first main surface and the second main surface of the heat-absorbing material; as well as A heat dissipation bag, which surrounds the heat-absorbing material and the heat-conducting sheet and includes a metal layer, The endothermic solution composition includes: Surfactants of about 0.20 wt.% to about 0.45 wt.%; Thickener, approximately 0.3 wt.% to approximately 5.0 wt.%; and Water, approximately 60 wt.% to approximately 80 wt.%.

2. The thermal barrier pad according to claim 1, wherein, The thickeners include carboxymethyl cellulose (CMC), carboxyethyl cellulose, polyvinyl alcohol (PVA), starch, polyethylene oxide (PEO), hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, or glucomannan.

3. The thermal barrier pad according to claim 1, wherein, The endothermic solution composition comprises about 15 wt.% to about 35 wt.% of antifreeze.

4. The thermal barrier pad according to claim 3, wherein, The antifreeze includes CaCl2, NaCl, potassium acetate, potassium formate, isopropanol, butyl diethylene glycol, ethylene glycol, diethylene glycol, dipropylene glycol, propylene glycol, urea, and / or glycerin.

5. The thermal barrier pad according to claim 3, wherein, The endothermic solution composition comprises about 20 wt.% to about 30 wt.% of antifreeze.

6. The thermal barrier pad according to claim 3, wherein, The endothermic solution composition comprises about 23 wt.% to about 27 wt.% of antifreeze.

7. The thermal barrier pad according to claim 1, wherein, The endothermic solution composition includes about 0.5 wt.% to about 3 wt.% of a thickener.

8. The thermal barrier pad according to claim 1, wherein, The endothermic solution composition comprises about 1 wt.% to about 2.2 wt.% of a thickener.

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 includes polydimethylsiloxane (PDMS).

11. The thermal barrier pad according to claim 1, wherein, The heat-conducting sheet includes copper, aluminum, zinc, tin, iron, or their alloys.

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

13. The thermal barrier pad according to claim 1, wherein, The heat-absorbing material includes nonwoven fabric with silica fiber as the main component.

14. A battery pack, comprising: Container assembly; Multiple secondary batteries, which are housed in the housing and stacked along a first direction; as well as According to claim 1, the thermal barrier pad is disposed between the plurality of secondary batteries.

15. A battery module, comprising: Module box; Multiple secondary batteries are housed in the module box and stacked along a first direction; as well as According to claim 1, the thermal barrier pad is disposed between the plurality of secondary batteries.

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