Heat absorbing sheet, battery cell, and battery module

Abstract

The present disclosure relates to a heat absorbing sheet, and a technical problem to be solved is to provide a heat absorbing sheet for cooling a temperature by means of a heat absorbing reaction. To this end, the present disclosure provides a heat absorbing sheet comprising: a powder-type first heat absorbing material layer; a powder-type second heat absorbing material layer which can react with the first heat absorbing material layer to perform a heat absorbing reaction; and a polymer layer positioned between the first heat absorbing material layer and the second heat absorbing material layer to separate the first heat absorbing material layer and the second heat absorbing material layer.

Description

Endothermic sheets, battery cells and battery modules

[0001] The present disclosure relates to a heat absorbing sheet, a battery cell including the heat absorbing sheet, and a battery module including the battery cell.

[0002]

[0003] Secondary batteries, unlike non-rechargeable primary batteries, are rechargeable and dischargeable. Low-capacity secondary batteries are used in small, portable electronic devices such as smartphones, feature phones, laptop computers, digital cameras, and camcorders, while large-capacity secondary batteries are widely used as power sources for motor drives and power storage in hybrid and electric vehicles. These secondary batteries include electrodes including a positive electrode and / or a negative electrode, an electrode assembly including the electrode, a case housing the electrode assembly, and electrode terminals connected to the electrode assembly.

[0004] Meanwhile, the internal temperature of these secondary batteries may rise if an internal short circuit occurs due to overcharging or overdischarging. Alternatively, the internal temperature of the secondary battery may rise due to an increase in external temperature.

[0005] When the internal temperature rises, the secondary battery may catch fire due to the melting of the separator caused by the heat generation of the electrode plates and components.

[0006] Secondary batteries are used in electronic devices closely related to people's daily lives, such as automobiles and smartphones. Therefore, to ensure human safety, it is necessary to reduce the risk of secondary battery fires and improve safety.

[0007] The above-described information disclosed in the background technology of this invention is only intended to improve understanding of the background of the present invention, and therefore may include information that does not constitute prior art.

[0008]

[0009] The present invention relates to a heat absorbing sheet for cooling the inside of a cell, a battery cell including the heat absorbing sheet, and / or a battery module including the battery cell.

[0010] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0011]

[0012] According to one embodiment of the present invention for solving the above technical problem, a heat absorbing sheet comprises: a first heat absorbing material layer in powder form; a second heat absorbing material layer in powder form that can react with the first heat absorbing material layer to undergo an heat absorbing reaction; and a polymer layer positioned between the first heat absorbing material layer and the second heat absorbing material layer to isolate the first heat absorbing material layer and the second heat absorbing material layer.

[0013] According to one embodiment of the present invention for solving the above technical problem, a battery cell comprises: an electrode assembly formed by stacking a positive electrode, a negative electrode, and a separator positioned between the positive electrode and the negative electrode; a can in which the electrode assembly is contained together with an electrolyte; and an endothermic sheet adhered to at least a portion of the inside of the can; wherein the endothermic sheet comprises: a first endothermic material layer in a powder form; a second endothermic material layer in a powder form capable of reacting with the first endothermic material layer to undergo an endothermic reaction; and a polymer layer positioned between the first endothermic material layer and the second endothermic material layer to isolate the first endothermic material layer and the second endothermic material layer.

[0014] A battery module according to one embodiment of the present invention for solving the above technical problem includes the battery cell described above; and a housing in which a plurality of battery cells are accommodated therein.

[0015]

[0016] According to the present invention, when the temperature inside the cell rises, the inside of the cell can be cooled.

[0017] According to the present invention, ignition and chain reaction due to an increase in temperature inside a cell can be prevented.

[0018] According to another aspect of the present invention, a battery pack (and / or module) manufactured using a battery cell having an improved structure and a vehicle including the same can be provided.

[0019] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects that are not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0020]

[0021] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0022] FIG. 1 is a drawing illustrating a cylindrical battery according to one embodiment of the present invention.

[0023] Figure 2 is a cross-sectional view of a cylindrical battery according to one embodiment of the present invention.

[0024] Figure 3 is an exploded perspective view of a pouch battery according to one embodiment of the present invention.

[0025] FIG. 4 is a drawing illustrating a square battery according to one embodiment of the present invention.

[0026] Figure 5 is a cross-sectional view of a square battery according to one embodiment of the present invention.

[0027] Figure 6 is an exploded view of a heat absorbing sheet according to one embodiment of the present invention.

[0028] Figure 7 is a perspective view of a heat absorbing sheet according to one embodiment of the present invention.

[0029] Figure 8 is a cross-sectional view of a battery cell according to one embodiment of the present invention.

[0030] Fig. 9 is a drawing explaining a heat absorption process of a heat absorption sheet according to one embodiment of the present invention.

[0031] FIG. 10 is a drawing illustrating a battery module according to one embodiment of the present invention.

[0032] FIG. 11 is a drawing illustrating a battery pack according to one embodiment of the present invention.

[0033] FIG. 12 is a drawing illustrating a battery pack according to one embodiment of the present invention.

[0034] FIG. 13 is a drawing illustrating a body and body parts according to one embodiment of the present invention.

[0035] FIG. 14 is a drawing illustrating a body and body parts according to one embodiment of the present invention.

[0036]

[0037] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms or words used in this specification and claims should not be interpreted as limited to their typical or dictionary meanings, and should be interpreted with meanings and concepts that conform to the technical spirit of the present invention based on the principle that the inventor can appropriately define the concept of a term to best explain his or her own invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are only some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as substitutes for them at the time of filing this application.

[0038] Additionally, when used herein, the terms "comprise", "include" and / or "comprising", "including" specify the presence of stated features, numbers, steps, operations, elements, elements and / or groups thereof, but do not preclude the presence or addition of one or more other features, numbers, operations, elements, elements and / or groups thereof.

[0039] Additionally, to facilitate understanding of the invention, the attached drawings are not drawn to scale and some components may be exaggerated in size. Furthermore, identical components may be assigned the same reference numbers in different embodiments.

[0040] The statement that two compared objects are "identical" means "substantially identical." Therefore, "substantially identical" may include deviations considered low in the art, such as deviations of less than 5%. Furthermore, uniformity of a parameter over a given region may imply uniformity on average.

[0041] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0042] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0043] Any configuration being placed "on (or under)" or "above (or below)" a component may mean not only that any configuration is placed in contact with the upper surface (or lower surface) of said component, but also that other configurations may intervene between said component and any configuration placed on (or below) said component.

[0044] Additionally, when it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through another component. Furthermore, when it is said that a part is electrically coupled to another part, this includes not only cases where they are directly connected, but also cases where they are connected with another element in between.

[0045] When reference is made throughout the specification to "A and / or B," this means A, B, or A and B, unless otherwise stated. In other words, "and / or" includes all or any combination of the listed items. When reference is made to "C through D," this means C or more and D or less, unless otherwise stated.

[0046] The terminology used herein is for the purpose of describing embodiments of the present disclosure and is not intended to be limiting of the present disclosure.

[0047]

[0048] FIG. 1 is a drawing illustrating a cylindrical battery according to one embodiment of the present invention.

[0049] Figure 2 is a cross-sectional view of a cylindrical battery according to one embodiment of the present invention.

[0050] As illustrated in FIGS. 1 and 2, a cylindrical lithium ion secondary battery (100) according to various embodiments of the present invention may include a cylindrical can (110), an electrode assembly (120), and a cap assembly (140). In addition, the cylindrical lithium ion secondary battery (100) may, in some cases, further include a center pin (130). In addition, in the secondary battery (100) according to an embodiment of the present invention, the cap assembly (140) also performs a current interrupt operation, and therefore, in some cases, it is also referred to as a current interrupt device.

[0051] The cylindrical can (110) may include a generally circular bottom portion (111) and a cylindrical side wall (112) extending upwardly from the circumference of the bottom portion (111) by a certain length. The top of the cylindrical can (110) is open during the manufacturing process of the secondary battery. Therefore, during the assembly process of the secondary battery, the electrode assembly (120) and the center pin (130) may be inserted into the cylindrical can (110) together with the electrolyte. The cylindrical can (110) may be manufactured from, for example, but not limited to, steel, stainless steel, aluminum, an aluminum alloy, or an equivalent thereof.

[0052] In addition, the cylindrical can (110) may include a beading part (113) sunken inwardly at the lower portion centered around the cap assembly (140) to prevent the cap assembly (140) from being detached to the outside, and a crimping part (114) bent inwardly at the upper portion thereof.

[0053] The electrode assembly (120) may be accommodated inside a cylindrical can (110). The electrode assembly (120) may include a negative electrode plate (121) in which a negative electrode active material (e.g., graphite, carbon, etc.) is coated on a negative electrode collector plate, a positive electrode plate (122) in which a positive electrode active material (e.g., transition metal oxide (LiCoO2, LiNiO2, LiMn2O4, etc.)) is coated on a positive electrode collector plate, and a separator (123) positioned between the negative electrode plate (121) and the positive electrode plate (122) to prevent short circuit and only allow movement of lithium ions. In addition, the negative electrode plate (121), the positive electrode plate (122), and the separator (123) may be wound in an approximately cylindrical shape. Here, for example and without limitation, the negative current collector may be made of copper (Cu) foil, the positive current collector may be made of aluminum (Al) foil, and the separator may be made of polyethylene (PE) or polypropylene (PP).

[0054] In addition, a negative electrode tab (124) that protrudes downwardly and is extended by a certain length may be welded to the negative electrode plate (121), and a positive electrode tab (125) that protrudes upwardly and is extended by a certain length may be welded to the positive electrode plate (122), but the opposite is also possible. In addition, for example, but not limited to, the negative electrode tab (124) may be formed of copper (Cu) or nickel (Ni), and the positive electrode tab (125) may be formed of aluminum (Al).

[0055] Additionally, the negative tab (124) of the electrode assembly (120) can be welded to the bottom (111) of the cylindrical can (110). Therefore, the cylindrical can (110) can operate as a negative electrode. Of course, conversely, the positive tab (125) can be welded to the bottom (111) of the cylindrical can (110), in which case the cylindrical can (110) can operate as a positive electrode.

[0056] In addition, a first insulating plate (126) coupled to a cylindrical can (110) and having a first hole (126a) formed in the center and a second hole (126b) formed on the outside thereof may be interposed between the electrode assembly (120) and the bottom portion (111). This first insulating plate (126) serves to prevent the electrode assembly (120) from electrically contacting the bottom portion (111) of the cylindrical can (110). In particular, the first insulating plate (126) serves to prevent the positive electrode plate (122) of the electrode assembly (120) from electrically contacting the bottom portion (111). Here, the first hole (126a) serves to allow the gas to quickly move upward through the center pin (130) when a large amount of gas is generated due to an abnormality in the secondary battery, and the second hole (126b) serves to allow the negative electrode tab (124) to pass through and be welded to the bottom (111).

[0057] In addition, a second insulating plate (127) coupled to a cylindrical can (110) and having a first hole (127a) formed in the center and a plurality of second holes (127b) formed on the outside thereof may be interposed between the electrode assembly (120) and the cap assembly (140). This second insulating plate (127) serves to prevent the electrode assembly (120) from electrically contacting the cap assembly (140). In particular, the second insulating plate (127) serves to prevent the negative plate (121) of the electrode assembly (120) from electrically contacting the cap assembly (140). Here, the first hole (127a) serves to allow the gas to quickly move to the cap assembly (140) when a large amount of gas is generated due to an abnormality in the secondary battery, and the second hole (127b) serves to allow the positive electrode tab (125) to pass through and be welded to the cap assembly (140). In addition, the remaining second hole (127b) serves to allow the electrolyte to quickly flow into the electrode assembly (120) during the electrolyte injection process.

[0058] In addition, the diameter of the first hole (126a, 127a) of the first and second insulating plates (126, 127) is formed to be smaller than the diameter of the center pin (130), thereby preventing the center pin (130) from electrically contacting the bottom (111) of the cylindrical can (110) or the cap assembly (140) due to external impact.

[0059] The center pin (130) is a hollow, circular pipe-shaped structure that can be connected to the approximate center of the electrode assembly (120). This center pin (130) can be made of, for example, but not limited to, steel, stainless steel, aluminum, an aluminum alloy, or polybutylene terepthalate. This center pin (130) suppresses deformation of the electrode assembly (120) during charging and discharging of the battery, and acts as a passage for gases generated inside the secondary battery. Of course, in some cases, this center pin (130) may be omitted.

[0060] The cap assembly (140) may include a top plate (141), a middle plate (142), an insulating plate (143), and a bottom plate (144).

[0061] The middle plate (142) is located at the bottom of the top plate (141) and may have a roughly flat shape.

[0062] The insulating plate (143) may be formed in a circular ring shape having a certain width when viewed from below. In addition, this insulating plate (143) serves to insulate the middle plate (142) and the bottom plate (144) from each other. For example, but not limited to, the insulating plate (143) may be interposed between the middle plate (142) and the bottom plate (144) and ultrasonically welded.

[0063]

[0064] Figure 3 is an exploded perspective view of a pouch battery according to one embodiment of the present invention.

[0065] As illustrated in FIG. 3, a typical secondary battery (100) is composed of an electrode assembly (110) and a pouch (130) that accommodates the electrode assembly (110).

[0066] The electrode assembly (110) includes a first electrode plate, a negative electrode plate (112), a second electrode plate, a positive electrode plate (114), and a separator (116) interposed therebetween. The negative electrode plate (112) is provided with a negative tab (112a) electrically connected to the negative electrode non-conductive portion, and the positive electrode plate (114) is provided with a positive tab (114a) electrically connected to the positive electrode non-conductive portion. The negative electrode tab (112a) and the positive electrode tab (114a) are welded to the negative electrode lead (152) and the positive electrode lead (154) of the external terminal, thereby being electrically connected to the outside. A tab film (156) for insulation from the pouch (130) is attached to the negative electrode lead (152) and the positive electrode lead (154).

[0067] The pouch (130) is sealed by having the sealing portions (132) at the edges contact each other while containing the electrode assembly (110). At this time, the sealing is performed while the tab film (156) is positioned between the sealing portions (132). As illustrated in Fig. 2, the form in which the tab film (156) is attached to each of the negative tab (112a) and the positive tab (114a) is defined as a 'separable tab film' (this sealing structure is defined as a separable sealing structure).

[0068] The sealing portion (132) of the pouch (130) is made of a heat-sealing material, and has a structure in which the heat-sealing layers are bonded to each other to form a seal. Since the heat-sealing material generally has weak adhesion to metal, a thin film-shaped tab film (156) is attached to the tab and fused to the pouch (130). However, the separate sealing structure has the problem of low workability and productivity because the tab film (156) must be individually attached to each tab, welded to the tab, and then heat-sealed again to the pouch (130).

[0069]

[0070] FIG. 4 is a drawing illustrating a square battery according to one embodiment of the present invention.

[0071] Figure 5 is a cross-sectional view of a square battery according to one embodiment of the present invention.

[0072] Referring to FIGS. 4 and 5, a secondary battery (100) according to the present embodiment may include at least one electrode assembly (10) wound between a positive electrode (11) and a negative electrode (12) with a separator (13) as an insulator interposed therebetween, a case (20) in which the electrode assembly (10) is built, and a cap assembly (30) coupled to an opening of the case (20).

[0073] The secondary battery (100) according to this embodiment is described as a square lithium ion secondary battery as an example. However, the present invention is not limited thereto, and the present invention can be applied to various types of batteries, such as lithium polymer batteries or cylindrical batteries.

[0074] The positive electrode (11) and the negative electrode (12) may include a coated portion, which is an area where an active material is applied to a current collector formed of a thin metal foil, and a non-coated portion (11a, 12a), which is an area where an active material is not coated.

[0075] The positive electrode (11) and the negative electrode (12) are wound with a separator (13) as an insulator interposed therebetween. However, the present invention is not limited thereto, and the electrode assembly (10) described above may be formed in a structure in which a positive electrode and a negative electrode made of a plurality of sheets are alternately laminated with a separator interposed therebetween.

[0076] The case (20) forms the overall appearance of the secondary battery (100) and may be formed of a conductive metal such as aluminum, an aluminum alloy, or nickel-plated steel. In addition, the case (20) may provide a space in which the electrode assembly (10) is accommodated.

[0077] The cap assembly (30) may include a cap plate (31) covering the opening of the case (20), and the case (20) and the cap plate (31) may be made of a conductive material. Here, positive and negative terminals (21, 22) electrically connected to the positive electrode (11) or the negative electrode (12) may be installed to protrude outwardly by penetrating the cap plate (31).

[0078] Additionally, the outer surface of the upper pillar of the positive and negative terminals (21, 22) protruding outward from the cap plate (31) can be threaded and fixed to the cap plate (31) with a nut.

[0079] However, the present invention is not limited thereto, and the positive and negative terminals (21, 22) may be riveted together by having a rivet structure, or may be welded together to the cap plate (31).

[0080] In addition, the cap plate (31) is made of a thin plate and can be joined to the opening of the case (20), and an electrolyte injection port (32) in which a sealing plug (33) can be installed can be formed in the cap plate (31), and a vent portion (34) in which a notch (34a) is formed can be installed.

[0081] The positive and negative terminals (21, 22) can be electrically connected to the current collectors including the first and second current collectors (40, 50) (hereinafter referred to as positive and negative current collectors) welded to the positive unconductive portion (11a) or the negative unconductive portion (12a).

[0082] For example, the positive and negative terminals (21, 22) may be joined to the positive and negative current collectors (40, 50) by welding. However, the present invention is not limited thereto, and the positive and negative terminals (21, 22) and the positive and negative current collectors (40, 50) may be formed by being joined together as one body.

[0083] Additionally, an insulating member may be installed between the electrode assembly (10) and the cap plate (31). Here, the insulating member may include first and second lower insulating members (60, 70), and each of the first and second lower insulating members (60, 70) may be installed between the electrode assembly (10) and the cap plate (31).

[0084] Additionally, according to the present embodiment, one end of a separating member that can be installed facing one side of the electrode assembly (10) can be installed between the insulating member and the positive or negative terminals (21, 22).

[0085] Here, the separating member may include first and second separating members (80, 90).

[0086] Accordingly, one end of the first and second separating members (80, 90) that can be installed facing one side of the electrode assembly (10) can be installed between the first and second lower insulating members (60, 70) and the positive and negative terminals (21, 22).

[0087] Finally, the positive and negative terminals (21, 22) welded to the positive and negative current collectors (40, 50) can be joined to one end of the first and second lower insulating members (60, 70) and the first and second separating members (80, 90).

[0088] However, the present invention is not limited thereto, and the case may be configured in various shapes, such as circular or pouch-shaped. In addition, the case may be configured of a metal such as aluminum, aluminum alloy, nickel-plated steel, or a laminate film or plastic forming a pouch.

[0089]

[0090] A battery cell (100) according to one embodiment of the present invention has been described with reference to FIGS. 1 to 5. Hereinafter, a heat-absorbing sheet, which is a structure applicable to the battery cell (100) and capable of cooling the interior of the battery cell (100) when the temperature inside and / or outside the battery cell (100) rises, will be described.

[0091]

[0092] Figure 6 is an exploded view of a heat absorbing sheet according to one embodiment of the present invention.

[0093] In Fig. 6, 200 represents a heat-absorbing sheet according to one embodiment of the present invention. The heat-absorbing sheet (200) undergoes an endothermic reaction under specific conditions. The specific conditions include, for example, a temperature environment within a predetermined range. Through this, the heat-absorbing sheet (200) can lower the surrounding temperature while absorbing surrounding heat.

[0094] This heat-absorbing sheet (200) includes a first heat-absorbing material layer (210), a second heat-absorbing material layer (220), and a polymer layer (230).

[0095] The first heat-absorbing material layer (210) and the second heat-absorbing material layer (220) are in powder form. If the coolant contained within the battery cell (100) includes a liquid such as a solvent, the liquid may flow out from the coolant, thereby reducing the safety of the battery cell (100). To prevent this risk, the first heat-absorbing material layer (210) and the second heat-absorbing material layer (220) are in a solid state, for example, in powder form.

[0096] Typically, the battery cell (100) operates at temperatures ranging from 0 to 40 degrees Celsius, which is the average temperature of the human environment, as it is applied to people's daily lives. Furthermore, assuming that the battery is used in extreme environments, the battery cell (100) operates at temperatures ranging from -20 to 75 degrees Celsius. Furthermore, the battery cell (100) is manufactured through various inspection steps (e.g., a chemical reaction process) to ensure proper charging and discharging. Accordingly, the internal temperature of the battery cell (100) may rise to, for example, approximately 90 degrees Celsius.

[0097] The first and second heat-absorbing material layers (210) are materials having a melting point higher than the operating temperature range of the battery cell (100). Furthermore, the first and second heat-absorbing material layers (210) are materials having a melting point higher than the temperature range that increases during the inspection step of the battery cell (100).

[0098] For example, in the inspection step for the battery cell (100), when the temperature of the battery cell (100) rises to 90 degrees, the first and second heat-absorbing material layers (210) may be materials having a melting point of 90 degrees or higher. However, the first and second heat-absorbing material layers (210) included in the heat-absorbing sheet (200) are materials having a melting point higher than the operating temperature range of the battery cell (100) to which they are applied. Accordingly, the heat-absorbing sheet (200) according to one embodiment of the present invention can prevent a risk that may occur due to the heat-absorbing material being in a liquid state such as a solvent.

[0099] In addition, as described above, the heat-absorbing sheet (200) utilizes an endothermic reaction between the first heat-absorbing material layer (210) and the second heat-absorbing material layer (220). Accordingly, the second heat-absorbing material layer (220) is a material that can react with the first heat-absorbing material layer (210) to undergo an endothermic reaction.

[0100] Accordingly, the first endothermic material layer (210) and the second endothermic material layer (220) are materials that each have a melting point of, for example, 90 degrees or higher and cause an endothermic reaction with each other. For example, the first endothermic material layer (210) is at least one selected from the group consisting of ammonium chloride (NH4Cl) or ammonium nitrate (NH4NO3) that satisfies this condition. Meanwhile, the second endothermic material layer (220) includes barium hydroxide (Ba(OH)2).

[0101] When the first endothermic material layer (210) is ammonium chloride (NH4Cl), for the efficiency of the reaction, the endothermic sheet (200) may include, for example, the first endothermic material layer (210) and the second endothermic material layer (220) in a molar ratio of 2:0.8 to 1.2. When the first endothermic material layer (210) is ammonium nitrate (NH4NO3), for the efficiency of the reaction, the endothermic sheet (200) may include, for example, the first endothermic material layer (210) and the second endothermic material layer (220) in a molar ratio of 2:0.8 to 1.2. However, this molar ratio is for the efficiency and is only an example. If an embodiment according to the present invention is to be implemented regardless of the efficiency, the first and second endothermic material layers (210, 220) having different ratios than the above-described may be included.

[0102] For convenience of explanation, the following description will be given as an example where the first endothermic material layer (210) is ammonium nitrate (NH4NO3).

[0103] As described above, the heat-absorbing sheet (200) causes an endothermic reaction through the heat-absorbing materials (210, 220). However, typically, when the battery cell (100) is being charged and discharged or applied in real life, it is necessary to prevent such an endothermic reaction from occurring. This is because there is no need to cool a battery cell (100) that is operating normally.

[0104] Accordingly, the heat-absorbing sheet (200) further includes a polymer layer (230) positioned between the first heat-absorbing material layer (210) and the second heat-absorbing material layer (220). The polymer layer (230) allows the first heat-absorbing material layer (210) and the second heat-absorbing material layer (220) to exist within the heat-absorbing sheet (200) in an isolated state. In addition, the polymer layer (230) melts when the internal temperature of the battery cell (100) rises, thereby allowing the first heat-absorbing material layer (210) and the second heat-absorbing material layer (220) to come into contact. Through this, the polymer layer (230) allows an endothermic reaction to occur between the first heat-absorbing material layer (210) and the second heat-absorbing material layer (220) when the internal temperature of the battery cell (100) rises. To this end, the polymer layer (230) may have the following characteristics.

[0105] In order to physically isolate the first heat-absorbing material layer (210) and the second heat-absorbing material layer (220) in powder form during normal operation of the battery cell (100), the polymer layer (230) needs to be in a solid state within the operating temperature range of the battery cell (100). Therefore, for example, the polymer layer (230) is a material having a melting point of 90 degrees or higher.

[0106] Meanwhile, if the temperature of the battery cell (100) exceeds a certain range, the battery cell (100) already enters a damage stage. Therefore, the polymer layer (230) must induce an endothermic reaction between the first heat-absorbing material layer (210) and the second heat-absorbing material layer (220) before the battery cell (100) is damaged. To this end, the polymer layer (230) is a material having a melting point that can melt at a temperature before the battery cell (100) is damaged.

[0107] In the case of a conventionally used battery cell (100), damage begins at a temperature range of about 120 degrees or higher. In this case, for example, the melting point of the polymer layer (230) is 120 degrees or lower. Therefore, in the case of a heat-absorbing sheet (200) applied to a conventional battery cell (100), the melting point of the polymer layer (230) is, for example, 90 to 120 degrees. Accordingly, the polymer layer (230) is at least one selected from the group consisting of, for example, LDPE (Low Density Polyethylene), LLDPE (Linear Low Density Polyethylene), and ABS (acrylonitrile butadiene styrene copolymer) resin.

[0108] Alternatively, if the normal operating temperature range of the battery cell (100) becomes higher, the melting point of the polymer layer (230) may also become higher. In this case, the polymer layer (230) may be at least one of, for example, PMMA (polymethyl methacrylate), polyacetal, PPE (polyphenylene ether), polystyrene, and PVC (polyvinyl chloride).

[0109] Below, the polymer layer (230) is described using LDPE as an example.

[0110] Meanwhile, for convenience of explanation, the first heat-absorbing material layer (210), the second heat-absorbing material layer (220), and the polymer layer (230) among the components included in the heat-absorbing sheet (200) may be collectively referred to as a heat-absorbing layer (A).

[0111] Meanwhile, in order for the heat-absorbing layer (A) to be efficiently positioned within the battery cell (100) (e.g., to prevent powder-type heat-absorbing materials from being scattered and positioned), the heat-absorbing sheet (200) may further include a component that supports and / or stores the heat-absorbing layer (A). For example, the heat-absorbing sheet (200) may further include a case (240) that performs this role.

[0112] The case (240) is formed in a shape that surrounds the heat-absorbing layer (A). Accordingly, the heat-absorbing layer (A) can be sealed while inserted into the case (240).

[0113] The case (240) is intended to store and / or support the heat-absorbing layer (A), and for example, it is necessary that no separate reaction occur while a chemical reaction (e.g., an endothermic reaction) occurs within the heat-absorbing layer (A). This is because if the case (240) reacts with the heat-absorbing layer (A), it may actually damage the battery cell (100). Meanwhile, as described above, the heat-absorbing layer (A) undergoes a chemical reaction as the polymer layer (230) melts. Therefore, the case (240) includes a material having a higher melting point than the polymer layer (230).

[0114] For example, as illustrated in FIG. 6, the case (240) may be laminated together with the heat-absorbing layer (A) to surround the heat-absorbing layer (A). In this case, the case (240) may include a first case (241) laminated on one side of the heat-absorbing layer (A) and a second case (242) laminated on the other side of the heat-absorbing layer (A). That is, the first case (241) may be formed on one side of the polymer layer (230) while covering the side of the first heat-absorbing material layer (210), and the second case (242) may be formed on the other side of the polymer layer (230) while covering the side of the second heat-absorbing material layer (220).

[0115] The case (240) is laminated and bonded to the heat-absorbing layer (A) by thermal bonding so as to be fixed thereto. For example, the first case (241) and the second case (242) are laminated and bonded to both sides of the polymer layer (230) by thermal bonding. Therefore, the case (240) includes, for example, a material capable of being thermally bonded.

[0116] In summary, the case (240) is a material having a higher melting point than the polymer layer (230) and capable of thermal bonding, such as PI (Polyimide).

[0117] Through the above-described components, the heat-absorbing sheet (200) according to one embodiment of the present invention can function as a coolant. For example, when the heat-absorbing sheet (200) is mounted on at least a portion of the inside of the battery cell (100), the heat-absorbing sheet (200) can lower the internal temperature of the battery cell (100) when the internal temperature rises. Meanwhile, although the battery cell (100) is used as an example as an object to which the heat-absorbing sheet (200) is applied, the heat-absorbing sheet (200) can be applied to all objects requiring temperature reduction when a specific temperature range is reached.

[0118] Through such a method, the heat-absorbing sheet (200) according to one embodiment of the present invention can prevent chain reactions, fire, etc. due to temperature rise inside the battery cell (100).

[0119]

[0120] Figure 7 is a perspective view of a heat absorbing sheet according to one embodiment of the present invention.

[0121] As described in FIG. 6, a heat absorbing sheet (200) according to one embodiment of the present invention includes a heat absorbing layer (A) and a case (240) surrounding the heat absorbing layer (A).

[0122] For example, the heat-absorbing sheet (200) can be formed through a step of providing a first heat-absorbing material layer (210) on a first case (241); a step of arranging a polymer layer (230) on the first heat-absorbing material layer (210) while covering the first heat-absorbing material layer (210); a step of providing a second heat-absorbing material layer (220) on the polymer layer (230); a step of arranging a second case (242) on the second heat-absorbing material layer (220) while covering the second heat-absorbing material layer (220); and a step of heat-fusing together the edges of the first case (241), the polymer layer (230), and the second heat-absorbing material layer (220).

[0123] Alternatively, for example, the heat-absorbing sheet (200) may be formed through a step of providing a first heat-absorbing material layer (210) on a first case (241); a step of arranging a polymer layer (230) on the first heat-absorbing material layer (210) while covering the first heat-absorbing material layer (210); a step of joining the first case (241) and the polymer layer (230) through heat fusion; a step of providing a second heat-absorbing material layer (220) on the polymer layer (230); a step of arranging a second case (242) on the second heat-absorbing material layer (220) while covering the second heat-absorbing material layer (220); and a step of joining the polymer layer (230) and the second heat-absorbing material layer (220) through heat fusion.

[0124] At this time, the arrangement order between the first heat-absorbing material layer (210) and the second heat-absorbing material layer (220) may be changed. At this time, the thermal bonding may be performed on the entire first case (241), the polymer layer (230), and the second case (242), or may be performed only on the edges of the first case (241), the polymer layer (230), and the second case (242).

[0125] In this case, the heat-absorbing sheet (200) has a sheet form in which a first case (241), a heat-absorbing layer (A), and a second case (242) are laminated. Accordingly, the heat-absorbing sheet (200) can be easily and conveniently attached and used anywhere that requires temperature cooling.

[0126] To this end, the heat-absorbing sheet (200) may include an adhesive layer (250) on at least one surface. Specifically, the adhesive layer (250) is formed on at least one surface of at least one of the first case (241) and the second case (242).

[0127] The adhesive layer (250) has adhesive properties and includes, for example, an adhesive tape, a polymer adhesive in particle or solution form, etc. The polymer adhesive includes, for example, polyvinylidene fluoride (PVdF), a polyvinylidene fluoride-hexafluoropropylene (PVdF-HFP) copolymer, or a combination thereof.

[0128] Through this method, the heat-absorbing sheet (200) according to one embodiment of the present invention can be easily fixed and applied anywhere. Below, an example in which such a heat-absorbing sheet (200) is applied to a battery cell (100) will be described.

[0129]

[0130] Figure 8 is a cross-sectional view of a battery cell according to one embodiment of the present invention.

[0131] FIG. 8 (a) is a cross-sectional view of a battery cell (300) (including, for example, the battery cell (100) described in FIGS. 1 to 7) in a long-side direction according to one embodiment of the present invention. FIG. 8 (b) is a cross-sectional view of a battery cell (300) in a short-side direction according to one embodiment of the present invention.

[0132] The battery cell (300) includes an electrode assembly (310) (e.g., including the electrode assembly (120) described in FIGS. 1 and 2, the electrode assembly (110) described in FIG. 3, and the electrode assembly (10) described in FIGS. 4 and 5), a can (320) (e.g., including the cylindrical can (110) described in FIGS. 1 and 2, the pouch (130) described in FIG. 3, and the case (20) described in FIGS. 4 and 5), and a heat-absorbing sheet (200).

[0133] The electrode assembly (310) is formed by laminating an anode, a cathode, and a separator positioned between the anode and the cathode. The can (320) is a space in which the electrode assembly (320) is contained together with an electrolyte. The heat-absorbing sheet (200) is adhered to at least a portion of the interior of the can (320).

[0134] As illustrated in (a) to (b) of FIG. 8, for example, the heat-absorbing sheet (200) is adhered to at least one of the lower surface (200b) and the side surface (200s) in the short or long direction inside the can (320). In addition, although not illustrated in FIG. 8, the heat-absorbing sheet (200) may also be adhered to the upper surface inside the can (320).

[0135] In this way, the heat-absorbing sheet (200) can be adhered to at least one surface inside the can (320) to contribute to cooling when the temperature of the battery cell (300) rises.

[0136]

[0137] Fig. 9 is a drawing explaining a heat absorption process of a heat absorption sheet according to one embodiment of the present invention.

[0138] In Fig. 9, the content of the chemical reaction occurring within the heat-absorbing sheet (200) described through Figs. 6 to 8 is described. In Fig. 9, the application of the heat-absorbing sheet (200) to a battery cell (300) is described as an example.

[0139] Figure 9 (a) shows a cross-sectional view of a heat-absorbing sheet (200) when the temperature inside the battery cell is within the normal operating range. Since the ambient temperature is below the melting point of the polymer layer (230), the heat-absorbing sheet (200) includes a first heat-absorbing material layer (210) and a second heat-absorbing material layer (220) that are separated from each other and are in a powder state.

[0140] Fig. 9 (b) shows a cross-sectional view of the heat-absorbing sheet (200) when the temperature inside the battery cell rises beyond the normal operating range. Since the ambient temperature is higher than the melting point of the polymer layer (230), the polymer layer (230) melts as illustrated in Fig. 9 (b). Accordingly, a chemical reaction occurs when the first heat-absorbing material layer (210) and the second heat-absorbing material layer (220) come into contact with each other. For example, when the first heat-absorbing material layer (210) is ammonium nitrate (NH4NO3) and the second heat-absorbing material layer (220) is barium hydroxide (Ba(OH)2), a reaction as shown in the following [Chemical Formula 1] occurs between the first heat-absorbing material layer (210) and the second heat-absorbing material layer (220).

[0141]

[0142] The first heat-absorbing material layer (210) and the second heat-absorbing material layer (220) absorb heat inside the battery cell (100) and lower the internal temperature of the battery cell (100) while performing an endothermic reaction according to [chemical formula 1]. At this time, the case (241, 242) does not react with the first heat-absorbing material layer (210) and the second heat-absorbing material layer (220).

[0143] In this way, the heat absorbing sheet (200) and the battery cell (300) equipped with the heat absorbing sheet (200) according to one embodiment of the present invention propose a cooling method for temperature rise.

[0144]

[0145] [Material]

[0146] Meanwhile, the battery cell (100, 300) according to one embodiment of the present invention described through FIGS. 1 to 9 includes, as described above, 1) an electrode assembly (310) and 2) a can (320) in which the electrode assembly (310) and an electrolyte are contained. At this time, the electrode assembly is formed by stacking a positive electrode, a negative electrode, and a separator positioned between the positive electrode and the negative electrode. At this time, a description of each component included in the battery cell (300) is as follows.

[0147] A compound capable of reversible intercalation and deintercalation of lithium (a lithiated intercalation compound) can be used as a cathode active material. Specifically, one or more of a composite oxide of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof can be used.

[0148] The above composite oxide may be a lithium transition metal composite oxide, and specific examples thereof include lithium nickel-based oxide, lithium cobalt-based oxide, lithium manganese-based oxide, lithium iron phosphate-based compound, cobalt-free nickel-manganese-based oxide, or a combination thereof.

[0149] As an example, a compound represented by any one of the following chemical formulas may be used: Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni 1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b-c Mn b Xc O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b Co c L 1 d G e O2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Li a NiG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-b G b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn2G b O4(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-g G g PO4(0.90≤a≤1.8, 0≤g≤0.5); Li (3-f) Fe2(PO4)3(0≤f≤2); Li a FePO4(0.90≤a≤1.8).

[0150] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; L 1 is Mn, Al or a combination thereof.

[0151] A positive electrode for a lithium secondary battery may include a current collector and a positive electrode active material layer formed on the current collector. The positive electrode active material layer includes a positive electrode active material and may further include a binder and / or a conductive material.

[0152] The content of the positive electrode active material may be 90 wt% to 99.5 wt% with respect to 100 wt% of the positive electrode active material layer, and the contents of the binder and conductive material may be 0.5 wt% to 5 wt%, respectively, with respect to 100 wt% of the positive electrode active material layer.

[0153] Al may be used as the above current collector, but is not limited thereto.

[0154] The negative electrode active material includes a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0155] The material capable of reversibly intercalating / deintercalating the lithium ions may include a carbon-based negative electrode active material, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite such as natural graphite or artificial graphite, and examples of the amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, and the like.

[0156] As the material capable of doping and dedoping the lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material can be used. The Si-based negative electrode active material can be silicon, a silicon-carbon composite, SiOx (0 < x < 2), a Si-based alloy, or a combination thereof.

[0157] The above silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles.

[0158] The silicon-carbon composite may further comprise crystalline carbon. For example, the silicon-carbon composite may comprise a core comprising crystalline carbon and silicon particles and an amorphous carbon coating layer positioned on the surface of the core.

[0159] A negative electrode for a lithium secondary battery includes a current collector and a negative electrode active material layer positioned on the current collector. The negative electrode active material layer includes a negative electrode active material and may further include a binder and / or a conductive material.

[0160] For example, the negative electrode active material layer may include 90 to 99 wt% of the negative electrode active material, 0.5 to 5 wt% of the binder, and 0 to 5 wt% of the conductive material.

[0161] The above binder may be a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof. When an aqueous binder is used as the negative electrode binder, a cellulose-based compound capable of imparting viscosity may be further included.

[0162] The negative electrode current collector may be selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and a combination thereof.

[0163] An electrolyte for a lithium secondary battery contains a non-aqueous organic solvent and a lithium salt.

[0164] The above non-aqueous organic solvent acts as a medium through which ions involved in the electrochemical reaction of the battery can move.

[0165] The above non-aqueous organic solvent may be a carbonate-based, ester-based, ether-based, ketone-based, or alcohol-based solvent, an aprotic solvent, or a combination thereof, and may be used alone or in combination of two or more thereof.

[0166] Additionally, when using a carbonate solvent, a mixture of cyclic carbonate and chain carbonate can be used.

[0167] Depending on the type of lithium secondary battery, a separator may be present between the positive and negative electrodes. Such separators may be polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer film comprising two or more layers of these.

[0168] The above separator may include a porous substrate and a coating layer comprising an organic material, an inorganic material, or a combination thereof, positioned on one or both sides of the porous substrate.

[0169] The above organic material may include a polyvinylidene fluoride-based antibody or a (meth)acrylic polymer.

[0170] The above inorganic materials are Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, It may include inorganic particles selected from, but not limited to, SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof.

[0171] The organic and inorganic substances may be mixed and present in one coating layer, or a coating layer including an organic substance and a coating layer including an inorganic substance may be present in a laminated form.

[0172]

[0173] FIG. 10 is a drawing illustrating a battery module according to one embodiment of the present invention.

[0174] Referring to FIG. 10, a battery module (1000) according to the present invention includes a plurality of battery cells (100) arranged in one direction (e.g., including the battery cells (100) described through FIGS. 1 to 7 and / or the battery cells (300) described through FIGS. 8 to 9) and a housing (1061, 1062, 1063, 1064) in which the plurality of battery cells (100) are accommodated inside.

[0175] The housing (1061 to 1064) may include a pair of end plates (1061, 1062) facing a wide surface of the battery cell (100), a side plate (1063) connecting the pair of end plates (1061, 1062), and a bottom plate (1064). The side plate (1063) may support the side surface of the battery cell (100), and the bottom plate (1064) may support the bottom surface of the battery cell (10). In addition, the pair of end plates (1061, 1062), the side plate (1063), and the bottom plate (1064) may be connected by a member such as a bolt (1065).

[0176]

[0177] FIG. 11 is a drawing illustrating a battery pack according to one embodiment of the present invention.

[0178] FIG. 12 is a drawing illustrating a battery pack according to one embodiment of the present invention.

[0179] A battery pack (2000) according to an embodiment of the present invention comprises a battery pack comprising individual batteries electrically connected to each other and a pack case housing the batteries. In the drawing, components such as bus bars, cooling units, and external terminals for electrical connection between the batteries are omitted for convenience of illustration.

[0180] Specifically, the battery pack (2000) may include a plurality of battery modules (1000) (e.g., including the battery module (1000) described in FIG. 10) and a pack case (2100) for accommodating the battery modules (1000). For example, the pack case (2100) may include first and second pack cases (2101, 2102) that are coupled in a direction facing each other with the plurality of battery modules (1000) interposed therebetween. The plurality of battery modules (1000) may be electrically connected to each other using a bus bar (2200), and the plurality of battery modules (1000) may be electrically connected to each other in a series / parallel or series-parallel mixed manner to obtain a required electrical output.

[0181]

[0182] FIG. 13 is a drawing illustrating a body and body parts according to one embodiment of the present invention.

[0183] FIG. 14 is a drawing illustrating a body and body parts according to one embodiment of the present invention.

[0184] The battery pack (2000) according to one embodiment of the present invention described in FIGS. 11 and 12 may be mounted on a vehicle (3000). The vehicle (3000) may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle may include a four-wheel vehicle or a two-wheel vehicle.

[0185] As illustrated in FIGS. 13 and 14, a vehicle (3000) according to one embodiment of the present invention includes a battery module (1000) according to one embodiment of the present invention and / or a battery pack (2000) including the battery module (1000). The vehicle (3000) operates by receiving power from the battery module (1000) according to one embodiment of the present invention and / or the battery pack (2000) including the battery module (1000).

[0186]

[0187] However, the present invention is not limited thereto, and the case may be configured in various shapes, such as circular or pouch-shaped. In addition, the case may be configured of a metal such as aluminum, aluminum alloy, nickel-plated steel, or a laminate film or plastic forming a pouch.

[0188]

[0189] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0190]

[0191] One embodiment of the present invention has industrial applicability.

Claims

1. A first endothermic material layer in powder form; A second endothermic material layer in powder form, which can react with the first endothermic material layer to undergo an endothermic reaction; and A polymer layer positioned between the first heat-absorbing material layer and the second heat-absorbing material layer, and insulating the first heat-absorbing material layer and the second heat-absorbing material layer; Absorbent sheet.

2. In paragraph 1, The first endothermic material layer comprises at least one selected from the group consisting of ammonium chloride and ammonium nitrate. Absorbent sheet.

3. In paragraph 1, The second endothermic material layer comprises barium hydroxide. Absorbent sheet.

4. In paragraph 1, The above polymer layer has a melting point of 90 to 120 degrees. Absorbent sheet.

5. In paragraph 1, The above polymer layer comprises at least one selected from the group consisting of LDPE, LLDPE, ABS, PMMA, polyacetal, polyphenylene ether, polystyrene and PVC. Absorbent sheet.

6. In paragraph 1, The above heat absorbing sheet, Including a molar ratio of the first endothermic material layer and the second endothermic material layer of 2:0.8 to 1.2, Absorbent sheet.

7. In paragraph 1, The above heat-absorbing sheet includes a first case covering the first heat-absorbing material layer side; and a second case covering the second heat-absorbing material layer side; The above first case and the above second case have a melting point higher than that of the polymer layer. Absorbent sheet.

8. In paragraph 7, The above first case and the above second case are joined by thermal fusion with the polymer layer. Absorbent sheet.

9. In paragraph 7, An adhesive layer is formed on at least one surface of at least one of the first case and the second case; Absorbent sheet.

10. An electrode assembly formed by laminating a positive electrode, a negative electrode, and a separator positioned between the positive electrode and the negative electrode; A can in which the above electrode assembly is embedded together with an electrolyte; and comprising a heat absorbing sheet adhered to at least a portion of the inside of the can; The above heat absorbing sheet, A first endothermic material layer in a powder form, a second endothermic material layer in a powder form that can react with the first endothermic material layer to undergo an endothermic reaction, and a polymer layer positioned between the first endothermic material layer and the second endothermic material layer to insulate the first endothermic material layer and the second endothermic material layer; Battery cells.

11. In Article 10, The above heat-absorbing sheet is located on at least one of the upper surface, side surface, and lower surface inside the can. Battery cells.

12. In paragraph 10, The first endothermic material layer comprises at least one selected from the group consisting of ammonium chloride and ammonium nitrate. Battery cells.

13. In paragraph 10, The second endothermic material layer comprises barium hydroxide. Battery cells.

14. In paragraph 10, The above polymer layer has a melting point of 90 to 120 degrees. Battery cells.

15. In paragraph 10, The above polymer layer comprises at least one selected from the group consisting of LDPE, LLDPE, ABS, PMMA, polyacetal, polyphenylene ether, polystyrene and PVC. Battery cells.

16. In paragraph 10, The above heat absorbing sheet comprises a molar ratio of the first heat absorbing material layer and the second heat absorbing material layer of 2:0.8 to 1.

2. Battery cells.

17. In paragraph 10, The above heat-absorbing sheet includes a first case covering the first heat-absorbing material layer side; and a second case covering the second heat-absorbing material layer side; The above first case and the above second case have a melting point higher than that of the polymer layer. Battery cells.

18. In paragraph 17, The above first case and the above second case are joined by thermal fusion with the polymer layer. Battery cells.

19. In paragraph 17, An adhesive layer is formed on at least one surface of at least one of the first case and the second case; Adhered to at least a portion of the inside of the can through the adhesive layer, Battery cells.

20. A battery cell according to any one of claims 10 to 19; and A housing including a plurality of battery cells housed therein; Battery module.

Images