Heat transfer suppressing member and battery pack

Abstract

The present invention provides a heat transfer suppressing member and a battery pack, the heat transfer suppressing member being capable of securing intervals between battery cells, suppressing damage to a battery case and deterioration in battery performance caused by deformation of the battery cells, and suppressing heat propagation between the battery cells during an abnormality, the battery pack can restrain heat transmission among battery units, and can restrain damage of a battery case and reduction of battery performance. The heat transfer suppressing member (50) has a frame body (53) that surrounds the outer periphery in plan view, and a sheet-like heat insulating material (10) that is disposed on the inside of the frame body (53) and that is provided with a pair of main surfaces (10s). Furthermore, in a cross-sectional view orthogonal to the plan view of the heat transfer suppressing member (50), the thickness of the heat insulating material (10) is thinner than the thickness of the frame body (53).

Description

Technical Field

[0001] The present invention relates to a heat transfer suppression component and a battery pack having the heat transfer suppression component. Background Technology

[0002] In recent years, from an environmental protection perspective, there has been active development of electric vehicles or hybrid vehicles powered by electric motors. These electric vehicles or hybrid vehicles are equipped with battery packs, which are composed of multiple battery cells connected in series or parallel, serving as the power source for the electric motors that drive the vehicles.

[0003] Furthermore, this battery cell primarily uses lithium-ion rechargeable batteries, which offer higher capacity and output compared to lead-acid and nickel-metal hydride batteries. Moreover, in cases of thermal runaway (i.e., "abnormal situations") where a battery cell experiences a rapid temperature rise and continued heat release due to internal short circuits, overcharging, or other reasons, heat from the thermally runaway cell propagates to adjacent battery cells, potentially causing thermal runaway in other cells. Additionally, if a battery cell experiences thermal runaway, gas is generated inside, increasing internal pressure and causing deformation of the battery cell.

[0004] As a countermeasure against thermal runaway as described above, Patent Document 1 discloses a heat transfer suppression sheet with excellent heat transfer suppression effect, which can maintain high thermal insulation performance by suppressing the reduction of the insulation material thickness even when the battery cell expands. The heat transfer suppression sheet described in Patent Document 1 includes a first insulation material and a second insulation material, wherein the thermal conductivity of the first insulation material is lower than that of the second insulation material. Furthermore, the compressive strength of the second insulation material is higher than that of the first insulation material, and the first insulation material is sandwiched between multiple second insulation materials.

[0005] Furthermore, Patent Document 2 discloses a thermal insulation material that, in response to compressive stress, maintains the structure of the insulation material while suppressing the deterioration of its thermal conductivity. The thermal insulation material described in Patent Document 2 comprises: a composite layer containing fibers and silica aerogel, and resin pillars arranged along the thickness direction in the composite layer.

[0006] The heat transfer suppression sheet and heat insulation material described in the aforementioned patent documents 1 and 2 both prevent the heat insulation material from being compressed, thus narrowing the gap between battery cells, thereby suppressing the decrease in thermal conductivity.

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2020-187869

[0010] Patent Document 2: Japanese Patent Application Publication No. 2017-215014 Summary of the Invention

[0011] The problem that the invention aims to solve

[0012] However, when the deformation of the battery cell caused by thermal runaway is significant, if a high-compressive-strength insulating material and resin support are provided in the area where the battery cell contacts the insulating material, as in Patent Documents 1 and 2, a reaction force is generated on the battery cell. During thermal runaway of a battery cell, the central region of its main surface is most prone to deformation. Therefore, if the spacing between cells in the central region is fixed by the insulating material, the outermost battery cells of multiple connected battery cells are pressed towards the battery casing. As a result, sometimes damage to the pressed battery cells and casing occurs. Furthermore, slight deformation of the battery cells also occurs during charge-discharge cycles of the battery pack (i.e., during "normal use"). Therefore, repeated increases and decreases in the internal pressure of the battery cell during charge-discharge cycles result in repeated pressing and mitigation of the battery cell based on the casing and insulating material, contributing to a decrease in battery performance.

[0013] In addition, the rapid expansion of the use of electric vehicles or hybrid vehicles necessitates the development of thermal insulation components with superior thermal insulation properties to ensure high safety.

[0014] The present invention was made in view of the above-mentioned problems, and its object is to provide a heat transfer suppression component and a battery pack. The heat transfer suppression component can ensure the spacing between battery cells, and can suppress damage to the battery casing and reduction in battery performance caused by deformation of battery cells, and can suppress the propagation of heat between battery cells in abnormal situations. The battery pack can suppress the propagation of heat between battery cells, and can suppress damage to the battery casing and reduction in battery performance.

[0015] Methods for solving problems

[0016] The above-mentioned objective of the present invention is achieved by the following [1] configuration relating to the heat transfer suppression component.

[0017] [1] A heat transfer suppression component, characterized in that it comprises: A frame that surrounds the outer perimeter when viewed from above; and Sheet-shaped thermal insulation material, disposed on the inner side of the frame, has a pair of main surfaces. In a cross-sectional view orthogonal to the top view, the thickness of the insulation material is thinner than the thickness of the frame.

[0018] Furthermore, preferred embodiments of the present invention relating to heat transfer suppression components include the following [2] to

[15] .

[0019] [2] The heat transfer suppression component according to [1] is characterized in that it has a membrane covering the main surface of the insulation material.

[0020] [3] The heat transfer suppression component according to [2] is characterized in that at least one of the pair of main surfaces has a gap between it and the membrane.

[0021] [4] The heat transfer suppression component according to [1] is characterized in that it has an elastic material laminated on at least one of the pair of main surfaces of the insulation material, wherein, in the cross-section, the thickness of the laminate of the insulation material and the elastic material is approximately the same as or thinner than the thickness of the frame.

[0022] [5] The heat transfer suppression component according to [4] is characterized in that the laminate has a pair of main surfaces orthogonal to the thickness direction, and the heat transfer suppression component has a film covering the pair of main surfaces.

[0023] [6] The heat transfer suppression component according to [5] is characterized in that at least one of the outer main surfaces has a gap between it and the membrane.

[0024] [7] The heat transfer suppression component according to [4] or [5] is characterized in that the elastic material comprises at least one selected from synthetic rubber, natural rubber and thermoplastic elastomer.

[0025] [8] The heat transfer suppression component according to any one of [1] to [7] is characterized in that it further comprises a partition wall dividing the inner side of the frame into multiple regions, and having a plurality of said heat insulation materials disposed in the multiple regions.

[0026] [9] The heat transfer suppression component according to [8] is characterized in that the plurality of heat insulation materials include a first heat insulation material and a second heat insulation material having different properties from each other.

[0027]

[10] The heat transfer suppression component according to [9] is characterized in that the elastic modulus of the first heat insulation material is less than the elastic modulus of the second heat insulation material.

[0028]

[11] The heat transfer suppression component according to

[10] is characterized in that the first heat insulation material is disposed in the region including the center of the plurality of regions.

[0029]

[12] The heat transfer suppression component according to any one of [8] to

[11] is characterized in that, when viewed from above, the width of the partition wall in the direction orthogonal to the length direction is smaller than the width of the frame in the direction orthogonal to the length direction.

[0030]

[13] The heat transfer suppression component according to any one of [8] to

[12] is characterized in that the partition wall is mainly made of insulating material.

[0031]

[14] The heat transfer suppression component according to any one of [1] to

[13] is characterized in that the frame is mainly made of insulating material.

[0032]

[15] The heat transfer suppression component according to any one of [1] to

[12] is characterized in that the heat insulation material comprises inorganic particles and organic fibers.

[0033] Furthermore, the above-mentioned objective of the present invention is achieved by the following configuration involving the battery pack

[16] .

[0034]

[16] A battery pack having a plurality of battery cells and a heat transfer suppression component as described in any one of [1] to

[15] , wherein the plurality of battery cells are connected in series or in parallel.

[0035] Invention Effects

[0036] The heat transfer suppression component of the present invention has a frame surrounding its outer periphery, thus ensuring the spacing between battery cells. Furthermore, a heat-insulating material is disposed inside the frame, and the thickness of the heat-insulating material is made thinner than the thickness of the frame, thereby suppressing damage to the battery casing caused by deformation of the battery cells and the degradation of battery performance, and suppressing the propagation of heat between battery cells during abnormal conditions.

[0037] The battery pack of the present invention has the above-mentioned heat transfer suppression component, and thus a battery pack can be obtained that can suppress the heat propagation between battery cells, suppress damage to the battery casing and the reduction of battery performance, and maintain excellent battery performance. Attached Figure Description

[0038] Figure 1A This is a top view showing the heat transfer suppression component according to the first embodiment of the present invention.

[0039] Figure 1B It is along Figure 1A A sectional view along line II.

[0040] Figure 2 This is a schematic cross-sectional view of a battery pack having a heat transfer suppression sheet according to a first embodiment of the present invention.

[0041] Figure 3 This is a cross-sectional view showing the heat transfer suppression component according to the second embodiment of the present invention.

[0042] Figure 4This is a cross-sectional view showing the heat transfer suppression component according to the third embodiment of the present invention.

[0043] Figure 5A This is a top view showing the heat transfer suppression component according to the fourth embodiment of the present invention.

[0044] Figure 5B It is along Figure 5A A sectional view along line II-II.

[0045] Figure 6 This is a top view showing a modified example 1 of the heat transfer suppression component according to the fourth embodiment of the present invention.

[0046] Figure 7 This is a top view showing a modified example 2 of the heat transfer suppression component according to the fourth embodiment of the present invention.

[0047] Figure 8 This is a photographic representation of an example 1 illustrating the construction of the heat transfer suppression component according to an embodiment of the present invention.

[0048] Figure 9 It is Figure 8 The accompanying photograph shows a portion of the insulation material as an enlarged view.

[0049] Figure 10 This is a photographic representation of an example 2 illustrating the construction of the heat-insulating material used in the heat transfer suppression component according to an embodiment of the present invention.

[0050] Figure 11 This is a schematic diagram illustrating Example 3 of the construction of the heat insulation material used in the heat transfer suppression component according to an embodiment of the present invention.

[0051] Figure 12 It is Figure 11 A schematic diagram showing a portion of the image.

[0052] Figure 13 It is shown Figure 11 The attached diagram of the insulation material is a substitute photograph.

[0053] Figure 14 This is a photographic representation of Example 4 illustrating the construction of the heat-transfer suppression component according to an embodiment of the present invention.

[0054] Figure 15 It is Figure 14 The accompanying diagram is a photograph showing an enlarged view of the structure of the insulation material.

[0055] Figure 16 It is shown Figure 14 The accompanying photograph shows a cross-section of the insulation material.

[0056] Figure 17 This is a schematic diagram illustrating Example 5 of the construction of the heat insulation material used in the heat transfer suppression component according to an embodiment of the present invention.

[0057] Figure 18 It is Figure 17 A schematic diagram showing an enlarged view of part A of the insulation material.

[0058] Figure 19 This is a photographic representation of Example 6 illustrating the construction of the heat-transfer suppression component according to an embodiment of the present invention.

[0059] Figure 20 It is shown Figure 19 The accompanying photograph shows other areas of the insulation material.

[0060] Figure 21 It is shown Figure 19 and Figure 20 The accompanying photograph shows a cross-section of the insulation material.

[0061] Figure 22 This is a photographic representation of Example 7 illustrating the construction of the heat transfer suppression component according to an embodiment of the present invention.

[0062] Figure 23 It is Figure 22 The accompanying photograph shows a portion of the insulation material as an enlarged view.

[0063] Figure 24 This is a schematic diagram illustrating an example of a method for defining the length of a fiber bundle.

[0064] Figure 25 It is shown Figure 22 The accompanying drawings are substitute photographs for other examples of the insulation material shown. Detailed Implementation

[0065] In order to obtain a heat transfer suppression component that can maintain the desired thermal insulation while suppressing unnecessary pressure on the battery cells and preventing performance degradation, the inventors conducted in-depth research. The results showed that the aforementioned problem can be solved by placing thermal insulation material inside the frame surrounding the outer perimeter, with the thickness of the thermal insulation material being thinner than the thickness of the frame. That is, by ensuring the spacing between battery cells through the frame and placing thermal insulation material thinner than the frame inside the frame, a buffer zone for the expansion of the battery cells can be ensured, reducing the pressure applied to the battery cells during expansion.

[0066] The following provides a detailed description of the heat transfer suppression component, its manufacturing method, and the battery pack according to embodiments of the present invention. It should be noted that the present invention is not limited to the embodiments described below, and can be implemented with arbitrary modifications without departing from the essential points of the present invention. First, the heat transfer suppression component according to an embodiment of the present invention will be described.

[0067] [Heat transfer suppression component]

[0068] [First Implementation Method]

[0069] Figure 1A This is a top view showing the heat transfer suppression component according to the first embodiment of the present invention. Figure 1B It is a cross-sectional view along its II line. For example... Figure 1A and Figure 1B As shown, the heat transfer suppression member 50 of the first embodiment includes: a frame 53 that surrounds the outer periphery when viewed from above; a sheet-like heat insulation material 10 disposed inside the frame 53 and having a pair of main surfaces 10s; and a film 52 adhered to a surface in the frame 53 parallel to the main surfaces of the heat insulation material 10. In this specification, "view from above" refers to the heat transfer suppression member viewed from above with the main surfaces of the heat insulation material 10 facing upwards and downwards. "Cross-sectional view" refers to a cross-section of the heat transfer suppression member viewed from a direction orthogonal to the above-view view. In this embodiment, the thickness of the heat insulation material 10 is thinner than the thickness of the frame 53. Therefore, gaps 54 are formed between the main surfaces 10s on both sides of the heat insulation material 10 and the film 52.

[0070] The following describes the specific usage of the heat transfer suppression component 50 of the first embodiment described above. Figure 2 This is a schematic cross-sectional view illustrating a battery pack having a heat transfer suppression sheet according to a first embodiment of the present invention. Figure 2 As shown, the heat transfer suppression component 50 can be used between multiple battery cells 20a, 20b, and 20c. Furthermore, the multiple battery cells 20a, 20b, and 20c are housed in the battery casing 30 in a series or parallel connection configuration (connection configurations are not shown in the diagram), forming a battery pack 100. It should be noted that battery cells 20a, 20b, and 20c are suitable for, for example, lithium-ion secondary batteries, but are not particularly limited to this and can also be applied to other secondary batteries.

[0071] In the heat transfer suppression component 50 of this first embodiment, frames 53 are respectively disposed between battery cells 20a and 20b, and between battery cells 20b and 20c. Therefore, by adjusting the thickness of the frames 53, the spacing between battery cells can be ensured at a desired interval. Furthermore, a heat-insulating material 10, thinner than the frame 53, is disposed inside the frames 53. Therefore, although a film 52 exists between the heat-insulating material 10 and the battery cells 20a, 20b, and 20c, a gap 54 is formed. When battery cells 20a, 20b, and 20c expand, the central portion of the main surface with the largest area in each battery cell typically protrudes. Therefore, the gap 54 acts as a receptacle for this expansion during expansion. Thus, unnecessary pressure on the battery cells 20a, 20b, and 20c can be suppressed, and the degradation of battery performance can be prevented.

[0072] In addition, the heat insulation material 10 has a specified heat insulation property. In this embodiment, there is a gap 54 between the heat insulation material 10 and the membrane 52, and air is present in the gap 54, so a better heat insulation effect can be obtained through the air.

[0073] Furthermore, in this embodiment, since the membrane 52 covers the main surface 10s of the heat insulation material 10, it is possible to prevent the battery casing 30 from being contaminated by the shedding of inorganic particles, i.e., dust, when the heat insulation material 10 contains, for example, inorganic particles.

[0074] It should be noted that in this embodiment, the membrane 52 is thermally fused to a portion of the frame 53, thereby making the membrane 52 a structure covering the main surface 10s of the heat insulation material 10. However, in this invention, the structure of the membrane 52 is not limited to this. For example, the membrane 52 can be configured to completely enclose the frame 53 and the heat insulation material 10, or it can be configured to only cover the heat insulation material 10, forming a gap between the membrane 52 and the battery cells 20a, 20b, and 20c.

[0075] Furthermore, the membrane 52 is not necessary in this invention. Even when the heat transfer suppression member does not have the membrane 52, since the thickness of the heat insulation material 10 is made thinner than that of the frame 53, a step is created between the frame 53 and the heat insulation material 10 in cross-section. Specifically, the main surface 10s of the heat insulation material 10 is a concave shape that is recessed compared to the frame 53. Therefore, when the heat transfer suppression member 50 is positioned between the battery cells 20a, 20b, and 20c, the presence of the frame 53 can ensure the clearance 54. As a result, it is possible to suppress the application of unnecessary pressure to the battery cells when they expand.

[0076] [Second Implementation]

[0077] Figure 3 This is a cross-sectional view showing a heat transfer suppression component according to a second embodiment of the present invention. Figure 3 In the heat transfer suppression component 120 shown, for the heat transfer suppression component 120, the heat transfer suppression component 12 Figure 1A and Figure 1B Components that are identical to those shown are labeled with the same symbols, and their detailed descriptions are omitted or simplified.

[0078] like Figure 3 As shown, the heat transfer suppression member 120 of the second embodiment has elastic material 51 laminated on the two main surfaces 10s of the heat insulation material 10. That is, the heat insulation material 10 is sandwiched by a pair of elastic materials 51 to form a laminate 111. In addition, the thickness of the laminate 111 is configured to be approximately the same as the thickness of the frame 53, and the membrane 52 is configured to cover the outer main surfaces 111s of the laminate 111. Therefore, the two outer main surfaces 111s of the laminate 111 are in most contact with the membrane 52, and no gaps are formed.

[0079] It should be noted that the thickness of the laminate 111 and the frame 53 being "approximately the same" means that the difference in their thicknesses is allowed to be ±5%, preferably ±3%, and more preferably ±1% of their average values.

[0080] The following is a detailed description of the application of the heat transfer suppression component 120 configured as described above in a battery pack. Here, alternatives... Figure 2 The heat transfer suppression component 50 of the battery pack 100 shown is used. Figure 3 The case of the heat transfer suppression component 120 shown will be explained.

[0081] In this embodiment, the heat transfer suppression member 120 also has a frame 53, so by adjusting the thickness of the frame 53, the spacing between battery cells can be ensured at the desired interval. Furthermore, an elastic material 51 is laminated on the two main surfaces 10s of the heat insulation material 10, and a film 52 is present on its outer surface. Therefore, even if the heat insulation material 10 contains inorganic particles, dust shedding can be further suppressed. In particular, even if the film 52 ruptures in an abnormal situation, if the main surfaces 10s of the heat insulation material 10 are covered by the elastic material 51, contamination caused by dust shedding can be prevented.

[0082] Furthermore, in the second embodiment, an elastic material 51 is provided instead of the gap 54 shown in the first embodiment. The elastic material 51 is elastic, and when the heat transfer suppression member 120 is pressed due to the expansion of the battery cells 20a, 20b, and 20c, the elastic material 51 deforms by an appropriate amount, thereby suppressing the reaction force on the battery cells. That is, when the battery cells 20a, 20b, and 20c deform, the elastic material 51 suppresses the deformation of the battery cells 20a, 20b, and 20c, and deforms softly relative to the deformation of the battery cells 20a, 20b, and 20c. Therefore, in the heat transfer suppression member 120 of the second embodiment, similarly to the first embodiment where the gap 54 is formed, the reduction in battery performance caused by repeated pressing and easing of the battery cells 20a, 20b, and 20c can be suppressed.

[0083] It should be noted that in the second embodiment, an elastic material 51 is laminated on both main surfaces 10s of the thermal insulation material 10, but the present invention is not limited to this, and the elastic material 51 can also be laminated by sandwiching it between a pair of thermal insulation materials 10. Alternatively, the elastic material 51 can be laminated only on one main surface of the thermal insulation material 10. In this case, compared with a three-layer laminate, the thickness of the two-layer laminate 111 of the thermal insulation material 10 and the elastic material 51 can be reduced. Specifically, the two-layer laminate 111 is preferably thinner than the frame 53, and the position of the laminate 111 in the thickness direction is preferably adjusted such that a gap is formed between the other main surface of the thermal insulation material 10 where the unlaminated elastic material 51 is not laminated and the battery cell.

[0084] Similar to the first embodiment, in the second embodiment, the membrane 52 may or may not be configured. When using a laminate 111 with a two-layer structure of the insulation material 10 and the elastic material 51, the membrane 52 is preferably configured to at least cover the main surface of the unlaminated elastic material 51 of the insulation material 10. Thus, by covering both main surfaces 10s of the insulation material 10 with either the elastic material 51 or the membrane 52, the effect of suppressing dust fallout can be achieved. Furthermore, the membrane 52 may be configured to completely enclose the frame 53, the insulation material 10, and the elastic material 51; it may be configured to enclose the laminate 111 of the insulation material 10 and the elastic material 51; or it may be configured to enclose only the insulation material 10.

[0085] [Third Implementation Method]

[0086] Figure 4 This is a cross-sectional view showing a heat transfer suppression component according to a third embodiment of the present invention. Figure 4 In the heat transfer suppression component 130 shown, for the heat transfer suppression component 130, the heat transfer suppression component 130 is used to suppress the heat transfer of ... Figure 1B and Figure 3 Components that are identical to those shown are labeled with the same symbols, and their detailed descriptions are omitted or simplified.

[0087] like Figure 4 As shown, in the third embodiment, the laminate 111 of the heat insulation material 10 and the elastic material 51 laminated on its two main surfaces 10s is formed to be thinner than the frame 53. In addition, the membrane 52 is configured to cover the outer main surfaces 111s of the laminate 111 through the gaps 54.

[0088] When a heat transfer suppression member 130 configured as described above is used instead of the heat transfer suppression member 50 of the battery pack 100, the same effects as in the first and second embodiments can be obtained. Furthermore, since there are gaps 54 on the two outer main surfaces 111s of the laminate 111, the heat insulation performance can be improved compared to the second embodiment. It should be noted that it is preferable to have a gap 54 between at least one of the outer main surfaces 111s of the laminate 111 and the membrane 52, and more preferably, to have a gap 54 between both outer main surfaces 111s and the membrane 52. In the third embodiment, the laminate 111 may also be constructed by laminating the elastic material 51 only on one main surface 10s of the heat insulation material 10. Furthermore, the presence and arrangement of the membrane 52 are the same as in the first and second embodiments.

[0089] [Fourth Implementation Method]

[0090] Figure 5A This is a top view showing the heat transfer suppression component according to the fourth embodiment of the present invention. Figure 5B It is a sectional view along its II-II line. Figure 5A and Figure 5B In the heat transfer suppression component 140 shown, for the heat transfer suppression component 140, the heat transfer suppression component 14 Figure 1A and Figure 1B Components that are identical to those shown are labeled with the same symbols, and their detailed descriptions are omitted or simplified.

[0091] The heat transfer suppression member 140 of the fourth embodiment has partition walls 58a and 58b that divide the inner side of the frame 53 into multiple regions. More specifically, the frame 53 is formed with partition walls 58a and 58b such that a pair of frame members 53a facing each other in the vertical direction are connected when the heat transfer suppression member 140 is placed between battery cells. Thus, the inner side of the frame 53 is divided into three regions: a first region 57a, a second region 57b, and a third region 57c. Furthermore, a second heat insulation material 10b, a first heat insulation material 10a, and a second heat insulation material 10b that are thinner than the frame 53 are respectively disposed in the first region 57a, the second region 57b, and the third region 57c. In this embodiment, the first heat insulation material 10a is made of a heat insulation material with a lower elastic modulus than the second heat insulation material 10b.

[0092] When a heat transfer suppression member 140 configured as described above is used instead of the heat transfer suppression member 50 of the battery pack 100, the spacing between the battery cells can be ensured by the frame 53, similar to the first and third embodiments. Furthermore, since a gap 54 is formed between the first heat insulation material 10a and the second heat insulation material 10b and the battery cells 20a, 20b, and 20c, unnecessary pressure on the battery cells can be suppressed even when the battery cells expand. Moreover, the air present in the gap 54 provides even better heat insulation.

[0093] As described above, on the widest outer surface (main surface) of battery cells 20a, 20b, and 20c, the center is more prone to protrusion due to expansion than the ends. Furthermore, terminals and vent valves are generally located above the battery cells; in abnormal situations, the vent valve side is prone to high temperatures and deformation. Therefore, in this embodiment, a first heat-insulating material 10a with a low elastic modulus is disposed in the central, vertically extending second region 57b, which is divided into three regions (first region 57a, second region 57b, and third region 57c), while second heat-insulating materials 10b with a higher elastic modulus than the first heat-insulating material 10a are disposed on both sides of it. That is, the first heat-insulating material 10a disposed in the central second region 57b is soft and has high resilience. Therefore, when battery cells 20a, 20b, and 20c expand and their central and upper parts deform in abnormal situations, the first heat-insulating material 10a with a low elastic modulus can further absorb the deformation of the battery cells.

[0094] It should be noted that in this embodiment, the multiple insulating materials disposed in the multiple regions divided by the partition wall have different elastic moduli, but insulating materials with different properties can also be used as needed. For example, an insulating material with extremely excellent thermal insulation properties can be disposed in the region with the highest temperature, while insulating materials with cost considerations can be disposed in other regions. When insulating materials with different properties are disposed in multiple regions, the type of insulating material is not limited to the first insulating material 10a and the second insulating material 10b, and three or more insulating materials with different properties can be used. In addition, the same elastic modulus can be disposed in all multiple regions. Even with such a structure, in this embodiment, since the thickness of the first insulating material 10a and the second insulating material 10b is thinner than the thickness of the frame 53, it is possible to suppress the application of unnecessary pressure to the battery cell when the battery cell expands.

[0095] Furthermore, by arranging multiple insulation materials in multiple areas, the volume of each insulation material can be reduced, making manufacturing easier and improving operability. Additionally, it is preferable to form the partition walls 58a and 58b in such a way that all the multiple areas have approximately the same shape and size. In this heat transfer suppression component, even if some insulation material is damaged in the event of an anomaly such as thermal runaway, the undamaged insulation material can be reused in other heat transfer suppression components, reducing the environmental impact.

[0096] It should be noted that the term "approximately the same" as mentioned above means that the difference in shape or size of each of the multiple regions is allowed to be within ±5%, preferably ±3%, and more preferably ±1% of the average value of all the multiple regions.

[0097] In this embodiment, similar to the first to third embodiments, the elastic material 51 can be disposed on both main surfaces of the first insulation material 10a and the second insulation material 10b, or it can be disposed on only one main surface. Alternatively, the elastic material 51 can be disposed in a manner where it is sandwiched between a pair of insulation materials. Furthermore, it is preferable, for example, to dispose of the elastic material 51 only on the first insulation material 10a, for example, on the inner side of the second region 57b, in one of the multiple regions.

[0098] In addition, similar to the first to third embodiments, a membrane can be configured to directly or indirectly cover the surfaces of the first thermal insulation material 10a and the second thermal insulation material 10b, and there are no particular limitations on the method of configuring the membrane.

[0099] <Modification 1 of the Fourth Embodiment>

[0100] Figure 6 This is a top view illustrating a modified example 1 of the heat transfer suppression component according to the fourth embodiment of the present invention. Figure 6 In the heat transfer suppression component 150 shown, for the heat transfer suppression component 150, the heat transfer suppression component 150 is used to suppress the heat transfer of ... Figure 5A The same components as the heat transfer suppression component 140 shown are labeled with the same symbols, and their detailed descriptions are omitted or simplified.

[0101] In Modification 1, the frame 53 is formed with partition walls 58a and 58b such that a pair of frame members 53b facing each other in the left-right direction are connected when the heat transfer suppression member 150 is positioned between the battery cells. Thus, the inner side of the frame 53 is divided into three regions from top to bottom: a first region 57a, a second region 57b, and a third region 57c. Furthermore, a first heat insulation material 10a, a second heat insulation material 10b, and a first heat insulation material 10b that are thinner than the frame 53 are respectively disposed in the first region 57a, the second region 57b, and the third region 57c. In this embodiment, the first heat insulation material 10a is made of a heat insulation material with a lower elastic modulus than the second heat insulation material 10b.

[0102] In the heat transfer suppression member 150 configured as described above, when it is used instead of the heat transfer suppression member 50 of the battery pack 100, the same effect as in the fourth embodiment described above can be obtained. As mentioned above, the central part of the main surface of the battery cells 20a, 20b, and 20c are prone to deformation, as are the upper parts where vent valves (not shown) are formed. Therefore, it is preferable to arrange the first heat insulation material 10a with a low elastic modulus in the central second region 57b and the upper first region 57a. It should be noted that the vent valve of the battery cell is not limited to the upper part and is sometimes arranged at the lower part. Therefore, when assembling the heat transfer suppression member 150 between battery cells 20a and 20b and between battery cells 20b and 20c, the combination of the first heat insulation material 10a and the second heat insulation material 10b can be designed taking into account the position of the vent valves, etc.

[0103] <Modification 2 of the Fourth Embodiment>

[0104] Figure 7 This is a top view illustrating a modified example 2 of the heat transfer suppression component according to the fourth embodiment of the present invention. Figure 7 In the heat transfer suppression component 160 shown, for the heat transfer suppression component 160, the heat transfer suppression component 160 is used to suppress the heat transfer of ... Figure 5A The same components as the heat transfer suppression component 140 shown are labeled with the same symbols, and their detailed descriptions are omitted or simplified.

[0105] In Modification 2, the frame 53 is formed with partition walls 58a and 58b such that a pair of frame members 53a facing each other in the vertical direction are connected when the heat transfer suppression member 160 is positioned between the battery cells. Additionally, partition walls 58c and 58d are formed to connect a pair of frame members 53b facing each other in the horizontal direction of the heat transfer suppression member 160. Thus, the inner side of the frame 53... Figure 7 The upper left side is divided into nine regions sequentially from right to left: a first region 57a, a second region 57b, a third region 57c, a fourth region 57d, a fifth region 57e, a sixth region 57f, a seventh region 57g, an eighth region 57h, and a ninth region 57i. Furthermore, a first thermal insulation material 10a, thinner than the frame 53, is disposed in the second region 57b and the fifth region 57e. Conversely, a second thermal insulation material 10b, thinner than the frame 53, is disposed in the regions other than those mentioned above. In this embodiment, the first thermal insulation material 10a is made of a thermal insulation material with a lower elastic modulus than the second thermal insulation material 10b.

[0106] In the heat transfer suppression member 160 configured as described above, when it is used instead of the heat transfer suppression member 50 of the battery pack 100, the same effect as in the fourth embodiment described above can be obtained. In this embodiment, a first heat insulation material 10a with a low elastic modulus is disposed in the fifth region 57e, which is located opposite the easily deformable positions of the battery cells 20a, 20b, and 20c, and in the second region 57b above it. That is, in the region where the battery cells are easily deformable, there is a gap between the first heat insulation material 10a and the battery cells, and the first heat insulation material 10a has a low elastic modulus, thus further reducing unnecessary pressure applied to the battery cells.

[0107] Furthermore, since the insulation material is configured in each of the nine divided areas, various insulation materials can be combined and designed as needed, increasing design flexibility. Moreover, because the size of each insulation material in the nine divided heat transfer suppression component 160 is smaller, the possibility of reusing undamaged insulation material in the event of thermal runaway or other anomalies increases, further reducing the environmental impact.

[0108] It should be noted that in the heat transfer suppression components 140, 150, and 160 with partition walls, it is preferable to place a first heat insulation material 10a with a low elastic modulus in at least the central region of the plurality of regions divided by the partition walls. Furthermore, when the heat transfer suppression components 140, 150, and 160 are arranged between battery cells 20a, 20b, and 20c, it is also preferable to place the first heat insulation material 10a near the vent valves of the battery cells 20a, 20b, and 20c.

[0109] Furthermore, while the partition wall serves to divide the inner side of the frame into multiple regions, if it is located near the center of the heat transfer suppression component when viewed from above, it acts as a resistor during battery charging and discharging, repeatedly pressing and relaxing the battery cells, thus degrading battery performance. Therefore, it is preferable that the partition wall is not located in the center or near the center of the inner side of the frame. (Refer to...) Figure 7 To explain, when a pair of frame members 53a facing each other in the vertical direction are connected by a partition wall, and considering the possibility of reusing the insulation material, it is preferable to form the partition wall in such a way that it equally divides the inner area of ​​the frame 53. In this case, in order to prevent the partition wall from existing in the center or near the center of the inner side of the frame, it is preferable to connect the pair of opposing frame members 53a with an even number of partition walls. When a partition wall is formed between a pair of frame members 53b facing each other in the horizontal direction, it is also preferable to connect the frame members 53b with an even number of partition walls.

[0110] Furthermore, the widths of the partition walls 58a to 58d in the heat transfer suppression components 140, 150, and 160 are not particularly limited. However, depending on the material constituting the partition wall, its heat insulation performance may sometimes be worse than that of the first heat insulation material 10a and the second heat insulation material 10b. Additionally, if the partition wall is primarily made of resin, the resin material may burn and disappear if the temperature around the heat transfer suppression component becomes extremely high during an abnormal event. In such cases, to maintain the heat insulation performance of the heat insulation material, it is preferable that the width of the partition wall in the direction orthogonal to the length direction when viewed from above is small. Specifically, it is preferable that the width of the partition walls 58a to 58d in the direction orthogonal to the length direction is smaller than the width of the frame 53 in the direction orthogonal to the length direction.

[0111] The materials constituting the heat transfer suppression component of this embodiment will be described below.

[0112] <Frame>

[0113] The frame serves to ensure spacing between adjacent battery cells under normal conditions. Therefore, the frame is preferably made primarily of an insulating material, and more preferably of a material with appropriate hardness and heat insulation properties. As the main material constituting the frame, at least one insulating material selected from resin materials, oxide ceramics, non-oxide ceramics, silicate minerals such as mica, and resin-ceramic composites is preferred. Among these, resin materials are preferred because they offer excellent processability in addition to properties such as hardness and heat insulation.

[0114] It should be noted that the shape of the frame is not particularly limited as long as it achieves the above-mentioned functions. For example, it can be made of inorganic fiber padding material.

[0115] <Separator>

[0116] In this embodiment, when the heat transfer suppression component has a partition wall, the partition wall effectively divides the inner side of the frame into multiple regions and holds multiple insulating materials together with the frame. Therefore, like the frame, the partition wall is preferably made of an insulating material as the main material, and more preferably of a material with appropriate hardness and heat insulation properties. That is, the partition wall is preferably made of at least one insulating material selected from resin materials, oxide ceramics, non-oxide ceramics, silicate minerals such as mica, and composite materials of resin and ceramics. Furthermore, from the viewpoints of hardness, heat insulation, and processability, the partition wall is more preferably made of a resin material as the main material. It should be noted that the frame and the partition wall can be integrally molded or formed by combining multiple parts. Regarding these materials, they can be made of the same material or different materials.

[0117] It should be noted that there are no particular limitations on the shape of the partition wall as long as it achieves the above-mentioned functions; for example, it can be made of inorganic fiber padding material.

[0118] Thermal insulation materials

[0119] There are no particular limitations on the type of insulation material as long as it achieves the desired insulation effect. Thermal conductivity can be used as an indicator of insulation effect. In this embodiment, the thermal conductivity of the insulation material is preferably less than 1 (W / m·K), more preferably less than 0.5 (W / m·K), and even more preferably less than 0.2 (W / m·K). Furthermore, the thermal conductivity of the insulation material is preferably less than 0.1 (W / m·K), more preferably less than 0.05 (W / m·K), and particularly preferably less than 0.02 (W / m·K). For example, insulation materials containing silicone rubber and aerogel, insulation materials containing fibers and aerogel, and insulation materials containing inorganic particles and organic fibers can be used to achieve the desired insulation effect. It should be noted that the thermal conductivity of the insulation material can be measured according to the "Test Method for Thermal Conductivity of Refractory Materials" described in JIS R 2251.

[0120] (Dimensions of the thermal insulation material)

[0121] In the case of laminated insulation and elastic materials, the size of the main surface of the insulation material and the size of the main surface of the elastic material orthogonal to the thickness direction can be approximately the same, or the elastic material can be formed to be smaller than the insulation material.

[0122] It should be noted that the term "roughly the same" as mentioned above means that the difference in the size of the main surfaces of the two is allowed to be ±5%, preferably ±3%, and more preferably ±1% of the average value of the two.

[0123] (Insulation materials including silicone rubber and aerogel)

[0124] As a thermal insulation material comprising silicone rubber and aerogel, an example is a thermal insulation material with a silicone rubber skeleton impregnated with SiO2. As for the silicone rubber, organosilicon and rubber with a heat resistance temperature of 170°C or higher can be used. It should be noted that aerogel has multiple pores, thus achieving excellent thermal insulation properties.

[0125] (Insulation materials containing fibers and aerogel)

[0126] Examples of thermal insulation materials that incorporate fibers and aerogels include those with a fiber framework impregnated with SiO2. The fibers used can be polyacrylonitrile (PAN) fibers, glass fibers, and ceramic fibers. It should be noted that aerogels, with their multiple pores, provide excellent thermal insulation.

[0127] (Insulation materials containing inorganic particles and organic fibers)

[0128] As a thermal insulation material containing inorganic particles and organic fibers, especially when using a thermal insulation material with the structure shown below, superior thermal insulation properties can be obtained compared to the aforementioned thermal insulation materials containing fibers and aerogels. Examples of such specific thermal insulation materials are described in detail below.

[0129] <Insulation Material (Structural Example 1)>

[0130] Figure 8 This is a photograph serving as a substitute for the accompanying drawing, illustrating Example 1 of the construction of the heat transfer suppression component according to an embodiment of the present invention. Figure 9 It is Figure 8 The accompanying photograph shows a portion of the insulation material as an enlarged view.

[0131] like Figure 8 and Figure 9 As shown, the thermal insulation material 10 comprises inorganic particles 4 and organic fibers 1. Furthermore, the thermal insulation material 10 has a plurality of three-dimensionally connected pores 7 between the inorganic particles 4 and the organic fibers 1. It should be noted that the organic fibers 1 have a welded portion 5 covering at least a portion of their surface, and at least a portion of the inorganic particles 4 is welded to the surface of the organic fibers 1 through the welded portion 5. Thus, the surface of the organic fibers 1 is configured to be covered by the inorganic particles 4.

[0132] In the heat insulation material 10 constructed in this way, due to the presence of multiple three-dimensionally connected pores 7, an air insulation effect can be achieved, further improving the heat insulation performance. Furthermore, the heat insulation material 10 contains highly flexible organic fibers 1, thus increasing its flexibility, and the organic fibers 1 easily intertwine with each other, thereby increasing the strength of the heat insulation material. Therefore, damage to the heat transfer suppression components with such heat insulation material 10 can be suppressed. Moreover, by having pores 7 in the heat insulation material 10, the overall buffering capacity of the sheet is improved. Therefore, when the battery cells 20a, 20b, and 20c expand during charging and discharging, the expansion amount can be absorbed by the gaps 54, and the expansion amount of the battery cells can also be absorbed by the heat insulation material 10, further suppressing the performance degradation of the battery cells.

[0133] Furthermore, in this embodiment, it is preferable that at least a portion of the aforementioned pore 7 communicates with the surface of the heat insulation material 10 and opens outwards. If the pore 7 is configured in this way, even if thermal runaway occurs in adjacent battery cells 20a, 20b, and 20c, and the heat insulation material 10 becomes extremely hot or the organic fibers 1 are decomposed, the decomposition gases will not remain inside the sheet but will be released to the outside through the pore 7. Therefore, from this perspective, the effect of preventing sheet damage can also be achieved.

[0134] Furthermore, if the welded portion 5 on the outer periphery of the organic fiber 1 fixes the inorganic particles 4 to the organic fiber 1, the effect of suppressing the shedding (powdering) of the inorganic particles 4 can be obtained. Therefore, even if, for example, a portion of the battery cells 20a, 20b, and 20c expands and applies compressive stress or impact to the heat transfer suppression member 50, the effect of maintaining the shape of the heat insulation material 10 can be further improved, and the reduction in heat insulation effect caused by the compression deformation of the heat insulation material 10 can be prevented.

[0135] In this specification, "welded portion 5" refers to the part where the surface of the organic fiber 1 is melted and then solidified again, which is the part formed in the manufacturing process of the insulation material 10 described later. In this embodiment, since the inorganic particles 4 are fused to the surface of the organic fiber 1 through the welded portion 5, the apparent fiber diameter of the organic fiber 1 becomes thicker and supports the shape of the insulation material 10, thus achieving high strength.

[0136] It should be noted that the welded portion 5 does not necessarily need to completely cover the outer peripheral surface of the organic fiber 1, and may also have areas where the welded portion 5 is not present. In the thermal insulation material 10, the adhesive fiber with a core-sheath structure described later can be used as the material for the organic fiber 1, but if the sheath peels off during the manufacturing process, the organic fiber 1, which is the core, may sometimes be partially exposed. Even in such cases, the effect of retaining the inorganic particles 4 can be sufficiently achieved.

[0137] Furthermore, the insulation material 10 preferably contains inorganic fibers. The effects obtained by containing inorganic fibers will be explained in the following example 2 of the insulation material's construction.

[0138] <Insulation Material (Structural Example 2)>

[0139] Figure 10 This is a photographic representation of an example 2 illustrating the construction of the heat-insulating material used in the heat transfer suppression component according to an embodiment of the present invention. Figure 10 In the construction example 2 shown, for the relationship with Figure 8 and Figure 9 The components shown in Example 1 are labeled with the same symbols, and detailed descriptions are omitted. It should be noted that... Figure 10 The insulation material 40 shown can be used, for example, as a... Figure 1A , Figure 1B , Figure 3 , Figure 4 The heat transfer suppression components 50, 120, and 130 shown have thermal insulation material 10. Figure 5A , Figure 5B , Figure 6 , Figure 7 The heat transfer suppression components 140, 150, and 160 shown include a first thermal insulation material 10a and a second thermal insulation material 10b.

[0140] like Figure 10 As shown, the thermal insulation material 40 has inorganic fibers 15. Furthermore, at least a portion of a first surface 40a orthogonal to its thickness direction and a second surface (not shown) of the thermal insulation material 40 are formed with fiber layers 11. The fiber layers 11 are formed by fusing at least a portion of multiple organic fibers 1 together at weld joints, creating a layered structure on the surfaces (first and second surfaces) of the thermal insulation material 40. That is, the fiber layers 11 are formed by aggregating 10 or more organic fibers 1 on the surface of the thermal insulation material 40, extending in a direction substantially parallel to the surface, for example, in a striped pattern.

[0141] Furthermore, a composite layer (not shown) is formed between the fiber layer 11 and the base layer 13 containing inorganic particles 4 and organic fibers 1, in which a portion of the fiber layer 11 and a portion of the inorganic particles 4 are mixed. Specifically, the composite layer is a region containing multiple organic fibers 1 that are at least partially fused together by welding portions, and inorganic particles 4 that are fused to the organic fibers 1 by welding portions.

[0142] It should be noted that, in Figure 10 In the insulation material 40 shown, inorganic fibers 15 are contained in the base layer 13 (which contains inorganic particles 4 and organic fibers 1), but may also be contained in the fiber layer 11. Figure 10 Since the inorganic fibers 15 in the fiber layer 11 cannot be distinguished, they are not shown.

[0143] Furthermore, the thermal insulation material 40 has a fiber bundle 6 formed by fusing at least a portion of multiple organic fibers 1 together through a welding portion 5. The "fiber bundle 6" is formed by interweaving 10 or more organic fibers 1 together and fusing a portion of the organic fibers 1 together, and is arranged in any direction in the thermal insulation material 40.

[0144] The heat insulation material 40 thus constructed contains inorganic fibers 15 that are difficult to decompose even at high temperatures. Therefore, for example, in the event of thermal runaway of the battery cell 20a and exposure of the heat transfer suppression component 50 disposed adjacent to the battery cell 20a to high temperatures, even if the organic fibers 1 in the heat insulation material 40 decompose, the inorganic fibers 15 remain, thus reliably maintaining the shape of the heat insulation material 40. In addition, the flexible organic fibers 1 easily wrap around the relatively stiff inorganic fibers 15, and a three-dimensional skeleton can be formed by the inorganic fibers 15 and the organic fibers 1, thereby further improving the strength of the heat insulation material 40.

[0145] Furthermore, if the insulation material 40 has a fiber layer 11 on its surface and fiber bundles 6 inside, it can achieve higher strength compared to the case where the organic fibers 1 are dispersed. It should be noted that the fiber layer 11 is not simply disposed on the base layer 13, but rather is a composite layer between the fiber layer 11 and the base layer 13, where a portion of the fiber layer 11 is mixed with a portion of the inorganic particles 4. Therefore, the fiber layer 11 is reliably constrained to the surface of the insulation material 40. Thus, the situation where only the fiber layer 11 detaches is not observed, and a high-strength insulation material 40 can be obtained. Additionally, as shown in the second embodiment, if an elastic material 51 is laminated into the insulation material, the pressure applied to the base layer 13 can be further reduced.

[0146] Furthermore, if a fiber layer 11 is formed on the surface of the insulation material 40, the fiber layer 11 can absorb the impact applied to the insulation material 40. Therefore, even without the elastic material 51 being laminated, the fiber layer 11 can be used to prevent the inorganic particles contained in the insulation material 40 from falling off.

[0147] <Insulation Material (Structural Example 3)>

[0148] Figure 11 This is a schematic diagram illustrating Example 3 of the construction of the heat insulation material used in the heat transfer suppression component according to an embodiment of the present invention. Figure 12 It is Figure 11 A partially enlarged schematic diagram. Additionally, Figure 13 It is shown Figure 11 The attached diagram shows a substitute photograph of the insulation material. Figures 11-13 In the construction example 3 shown, for the relationship with Figure 8 and Figure 9 The components shown in Example 1 are labeled with the same symbols, and detailed descriptions are omitted. It should be noted that... Figures 11-13 The insulation material 60 shown can be used, for example, as a heat insulation material. Figure 1A , Figure 1B , Figure 3 , Figure 4 The heat transfer suppression components 50, 120, and 130 shown have thermal insulation material 10. Figure 5A , Figure 5B , Figure 6 , Figure 7 The heat transfer suppression components 140, 150, and 160 shown include a first thermal insulation material 10a and a second thermal insulation material 10b.

[0149] like Figures 11-13As shown, the thermal insulation material 60 of this embodiment has inorganic particles 4, organic fibers 1 made of a first organic material, and a welded portion 5 covering the outer peripheral surface of the organic fibers 1. As described above, the welded portion 5 includes a second organic material 17 having a melting point lower than that of the first organic material and the inorganic particles 4. It should be noted that in this embodiment, as the organic fiber, an adhesive fiber 3 with a core-sheath structure having a core and a sheath covering the outer peripheral surface of the core is used, and the organic fiber 1 corresponds to the core. In addition, the welded portion 5 is formed by temporarily melting the sheath of the adhesive fiber 3 with the core-sheath structure by heating and then cooling it. Furthermore, as Figure 13 As shown, a fiber section 16 is formed by organic fibers 1 and a welded section 5 containing inorganic particles 4, and a base material section 18 containing inorganic particles is formed between multiple fiber sections 16. In addition, when the molten sheath is cooled, adjacent organic fibers 1 are fused together at the contact section 31 to form a three-dimensional skeleton.

[0150] In the heat insulation material 60 constructed in this way, the organic fibers 1 and the welded portions 5 act as a framework, thus achieving excellent strength and shape retention. Furthermore, the welded portions 5, covering the outer peripheral surface of the organic fibers on both the surface and center sides of the heat insulation material 60, fix the inorganic particles 4 to the organic fibers 1, thereby suppressing dust shedding. Therefore, even when a heat transfer suppression member 50 containing the heat insulation material 60 is arranged between multiple battery cells, and the battery cells expand, applying compressive stress or impact to the heat transfer suppression member 50, excellent heat insulation performance can still be maintained.

[0151] The mechanism by which the inorganic particles 4 can be suppressed from falling off (dust) in the aforementioned thermal insulation material 60 is not yet certain, but one reason is believed to be that the organic fibers 1 and the welded portion 5 form a three-dimensional and robust skeleton, maintaining the shape of the thermal insulation material 60, thus suppressing deformation or compression of the thermal insulation material 60. Furthermore, as shown in the second and third embodiments described above, it is believed that if an elastic material 51 is laminated on at least one surface of the thermal insulation material 60, the pressure on the thermal insulation material 60 is reduced, further suppressing the falling off of the inorganic particles 4.

[0152] It should be noted that regardless of whether the surface of the insulation material 60 has the elastic material 51, the exposed fiber portion 16 on the surface of the insulation material 60 can absorb the impact applied to the insulation material 60, which is also considered a reason for retaining the inorganic particles 4. Furthermore, in this embodiment, since the thickness of the insulation material is formed to be thinner than that of the frame 53, it can absorb the impact applied to the insulation material in the same way as the fiber portion 16, thereby improving the effect of retaining the inorganic particles 4.

[0153] like Figure 13As shown, in the thermal insulation material 60, the welded portion 5 does not need to completely cover the outer peripheral surface of the organic fiber 1, and the organic fiber 1 can be partially exposed. Since the thermal insulation material 60 uses adhesive fiber 3 with a core-sheath structure, the sheath may sometimes peel off during the manufacturing process of the thermal insulation material 60, but even when the organic fiber 1 is partially exposed, the effects of the present invention can still be fully obtained.

[0154] <Insulation Material (Structural Example 4)>

[0155] Figure 14 This is a photograph serving as a substitute for the accompanying drawing, illustrating Example 4 of the construction of the heat transfer suppression component according to an embodiment of the present invention. Figure 15 It is Figure 14 The accompanying diagram is a photograph showing an enlarged view of the structure of the insulation material. Figure 16 It is shown Figure 14 The accompanying photograph shows a cross-section of the insulation material. Figures 14-16 In the construction example 4 shown, for the relationship with Figure 8 and Figure 9 The components shown in Example 1 are labeled with the same symbols, and detailed descriptions are omitted. It should be noted that... Figures 4 to 16 The insulation material 70 shown can be used, for example, as a heat insulation material. Figure 1A , Figure 1B , Figure 3 , Figure 4 The heat transfer suppression components 50, 120, and 130 shown have thermal insulation material 10. Figure 5A , Figure 5B , Figure 6 , Figure 7 The heat transfer suppression components 140, 150, and 160 shown include a first thermal insulation material 10a and a second thermal insulation material 10b.

[0156] like Figure 14 and Figure 15 As shown, the thermal insulation material 70 has a matrix 14 containing inorganic particles 4 and organic fibers 1 three-dimensionally oriented in the matrix 14. Furthermore, the organic fibers 1 have welded portions 5 covering at least a portion of their surface, and the organic fibers 1 are welded together through the welded portions 5. Similarly, the inorganic particles 4 are also welded to the surface of the organic fibers 1, thus forming a structure in which the surface of the organic fibers 1 is covered by inorganic particles 4.

[0157] In addition, such as Figure 16 As shown in the cross-sectional view, a plurality of pores 7 are formed in the matrix 14 of the insulation material 70. Furthermore, in the matrix 14, at least a portion of the plurality of organic fibers 1 are interposed of each other. Figure 16 The fusion section 5 (not shown) is fused together to form a fiber bundle 6, and a gap 8 is formed between the multiple organic fibers 1 that make up the fiber bundle 6.

[0158] Furthermore, a fiber layer 11 is formed on at least a portion of a first surface 70a orthogonal to the thickness direction and a second surface (not shown) of the insulation material 70. The fiber layer 11 is formed in a layered manner on the surface (first and second surfaces) of the insulation material 70 by fusing at least a portion of multiple organic fibers 1 together through a welding portion 5. In addition, a composite layer 12 is formed between the fiber layer 11 and the base layer 13 containing the matrix 14 and the organic fibers 1. The composite layer 12 is a layer in which a portion of the fiber layer 11 and a portion of the matrix 14 are mixed. Specifically, the composite layer 12 is a region containing multiple organic fibers 1 that are at least partially fused together through the welding portion 5 and inorganic particles 4 fused to the organic fibers 1 through the welding portion 5.

[0159] It should be noted that the fiber bundle 6 is formed by interweaving 10 or more organic fibers 1 and fusing the organic fibers 1 together in a portion, and is arranged in any direction in the matrix 14 of the insulation material 70. On the other hand, the fiber layer 11 is a layer formed by assembling 10 or more organic fibers 1 on the surface of the insulation material 70, and extends in a stripe-like pattern in a direction substantially parallel to the surface.

[0160] In the insulation material 70 constructed in this way, the organic fibers 1 are three-dimensionally oriented to each other in the matrix 14, and the organic fibers 1 have welded portions 5 covering at least a portion of their surfaces. "Welded portion 5" refers to the area where the surface of the organic fiber 1 is melted and then re-cured, and is formed during the manufacturing process of the insulation material 70. In the insulation material 70, the three-dimensionally oriented organic fibers 1 are welded to each other through the welded portions 5, thus this structure forms a skeleton and supports the shape of the insulation material 70, resulting in high strength.

[0161] Similarly, in the heat insulation material 70, the welded portion 5 on the outer peripheral surface of the organic fiber 1 also fixes the inorganic particles 4 to the organic fiber 1, thus achieving a higher dust suppression effect. Therefore, for example, during the charging and discharging of battery cells 20a, 20b, and 20c, even if a portion of it expands and applies compressive stress or impact to the heat transfer suppression member 50, in this embodiment, the shape of the heat insulation material 70 can be maintained by the effect of the welded portion 5 and the frame 53. As a result, the shedding (dust) of the inorganic particles 4 can be suppressed, and the reduction in heat insulation effect caused by the compression deformation of the heat insulation material 70 can be prevented.

[0162] In the insulation material 70, the mechanism for suppressing the inorganic particles 4 from falling off the sheet surface is considered to be the same as that of the insulation material 60 in the above-described structural example 3.

[0163] It should be noted that in the insulation material 70, the welded portion 5 does not need to completely cover the outer peripheral surface of the organic fiber 1, and may also have areas where the welded portion 5 is not present. Even in such cases, the effect of retaining the inorganic particles 4 can be sufficiently achieved.

[0164] In addition, the insulation material 70 contains highly flexible organic fibers 1, which improves the flexibility of the insulation material 70. Furthermore, the organic fibers 1 can easily intertwine with each other, thereby increasing the strength of the sheet.

[0165] Furthermore, in the insulation material 70, since there are multiple pores 7 in the matrix 14 and gaps 8 between the multiple organic fibers 1 constituting the fiber bundle 6, the insulation performance can be improved. Additionally, due to the presence of the gaps 8, the organic fibers 1 are less likely to be confined within the matrix 14, thus further improving the flexibility and strength of the insulation material 70. The gaps 8 do not need to be formed over the entire area between the multiple organic fibers 1; forming gaps 8 in at least a portion between the organic fibers 1 is sufficient to achieve a heat transfer suppression effect. It should be noted that, as shown in the first and third embodiments described above, if the gaps 54 are present on the main surface side of the insulation material, a further heat transfer suppression effect can be obtained.

[0166] Furthermore, since the insulation material 70 has fiber bundles 6 and fiber layers 11, it can achieve higher strength compared to the case where organic fibers 1 are dispersed. In addition, the fiber layers 11 are not simply disposed on the base layer 13, but rather there is a composite layer 12 between the fiber layers 11 and the base layer 13, in which a portion of the fiber layers 11 is mixed with a portion of the inorganic particles 4 constituting the matrix 14, thus reliably constraining the fiber layers 11 to the surface of the insulation material 70. Therefore, a high-strength insulation material 70 can be obtained.

[0167] <Insulation Material (Structural Example 5)>

[0168] Figure 17 This is a schematic diagram illustrating Example 5 of the construction of the heat insulation material used in the heat transfer suppression component according to an embodiment of the present invention. Figure 18 It is Figure 17 A schematic diagram showing an enlarged view of part A of the insulation material. Figure 17 and Figure 18 In the construction example 5 shown, for the relationship with Figure 8 and Figure 9 The components shown in Example 1 of the insulation material construction are labeled with the same symbols, and detailed descriptions are omitted. It should be noted that... Figures 17-18 The insulation material 80 shown can be used, for example, as a heat insulation material. Figure 1A , Figure 1B , Figure 3 , Figure 4 The heat transfer suppression components 50, 120, and 130 shown have thermal insulation material 10. Figure 5A , Figure 5B , Figure 6 , Figure 7The heat transfer suppression components 140, 150, and 160 shown include a first thermal insulation material 10a and a second thermal insulation material 10b.

[0169] like Figure 17 and Figure 18 As shown, the thermal insulation material 80 has a matrix 14 containing inorganic particles 4, inorganic fibers 15 dispersed in the matrix 14, and organic fibers 1. Furthermore, the organic fibers 1 and inorganic fibers 15 are interwoven to form a three-dimensional network structure. It should be noted that in this embodiment, an air layer 28 is formed around a portion of the inorganic fibers 15. Additionally, a portion of the surface of the organic fibers 1 has a welded portion 5, through which at least a portion of the inorganic fibers 15 is welded to the organic fibers 1. Furthermore, at least a portion of the inorganic particles 4 is welded to the organic fibers 1 through the welded portion 5.

[0170] It should be noted that in this specification, the inorganic fiber 15 is "dispersed" to mean that the inorganic fiber 15 is configured in an overall extended manner without extreme uneven distribution.

[0171] In the heat insulation material 80 constructed in this way, organic fibers 1 and inorganic fibers 15 are interwoven to form a three-dimensional network structure, which serves as a skeleton, thus achieving high strength. Therefore, during the charging and discharging of battery cells 20a, 20b, and 20c, even when the heat transfer suppression component 50 is compressed due to the expansion of the battery cells, the shape of the heat insulation material 80 can be maintained through the skeleton structure based on organic fibers 1 and inorganic fibers 15 and the effect of the frame 53. As a result, the shedding (dust shedding) of inorganic particles 4 can be suppressed, and the reduction in heat insulation effect caused by the compression deformation of the heat insulation material 80 can be prevented.

[0172] Furthermore, the thermal insulation material 80 includes highly flexible organic fibers 1, thus improving its flexibility. The organic fibers 1 and inorganic fibers 15 are also intertwined to easily form a three-dimensional mesh structure, which also improves its strength. Additionally, if the thermal insulation material 80 includes inorganic fibers 15, then, for example, in the event of thermal runaway of the battery cell 20a or exposure of the heat transfer suppression component adjacent to the battery cell 20a to high temperatures, the shape of the heat transfer suppression component can be maintained even if the organic fibers 1 decompose. Therefore, by incorporating highly flexible organic fibers 1 and inorganic fibers 15 that do not decompose even at high temperatures, the thermal insulation material 80 provides a heat transfer suppression component that balances both flexibility and strength.

[0173] Furthermore, in this embodiment, an air layer 28 is provided around the inorganic fibers 15 dispersed in the matrix 14. The inorganic fibers 15 have a higher thermal conductivity than the organic fibers 1, but as described above, by forming an air layer 28 around the inorganic fibers 15, heat transfer between the inorganic fibers 15 and the matrix 14 can be suppressed. It should be noted that the air layer 28 is formed during the manufacturing process of the insulation material 80, but it is not necessary to form the air layer 28 over the entire area around the inorganic fibers 15; as long as the air layer 28 is formed on at least a portion of the outer peripheral surface of the inorganic fibers 15, the heat transfer suppression effect can be obtained.

[0174] If the inorganic fibers 15 are uniformly dispersed in the matrix 14, the air layers 28 in the matrix 14 are also uniformly dispersed, thus the insulation material 80 can uniformly obtain high insulation performance. It should be noted that, as shown in the first and third embodiments above, if the insulation material has voids 54 on the main surface side, even higher insulation performance can be obtained.

[0175] Furthermore, in the thermal insulation material 80, the organic fiber 1 has a welded portion 5 covering at least a portion of its surface. "Welded portion 5" refers to the area where the surface of the organic fiber 1 is melted and then solidified again, formed during the manufacturing process of the thermal insulation material 80. If at least a portion of the inorganic fiber 15 is welded to the organic fiber 1 through the welded portion 5, the interwoven organic fiber 1 and inorganic fiber 15 are fixed, thus enabling the thermal insulation material 80 to achieve higher strength.

[0176] Similarly, in this embodiment, the welded portion 5 on the outer peripheral surface of the organic fiber 1 also fixes the inorganic particles 4 to the organic fiber 1, thus achieving a higher dust suppression effect. Therefore, even if, for example, a portion of the battery cells 20a, 20b, or 20c expands, imposing compressive stress or impact on the heat transfer suppression component, excellent thermal insulation performance can be maintained.

[0177] In this embodiment, the mechanism for suppressing the detachment of inorganic particles 4 from the sheet surface is considered to be due to the fact that organic fibers 1 and inorganic fibers 15 are fused together through the weld joint 5 to form a three-dimensional and robust skeleton, thus maintaining the shape of the insulation material 80 and suppressing the deformation or compression of the heat transfer suppression component. Furthermore, regardless of whether the surface of the insulation material 80 has elastic material 51, if the organic fibers 1 and inorganic fibers 15 are exposed on the surface of the insulation material 80, they can absorb the impact applied to the insulation material 80 and retain the inorganic particles 4.

[0178] Furthermore, in this embodiment, since the thickness of the insulation material is made thinner than that of the frame 53, it can absorb the impact applied to the insulation material, just like the effect of the fiber portion 16, and can improve the effect of retaining the inorganic particles 4.

[0179] It should be noted that in the insulation material 80, the welded portion 5 does not need to completely cover the outer peripheral surface of the organic fiber 1, and may also have areas where the welded portion 5 is not present. Even in such cases, the effect of retaining the inorganic particles 4 can be sufficiently achieved.

[0180] <Insulation Material (Structural Example 6)>

[0181] Figure 19 This is a photograph serving as a substitute for the accompanying drawing, illustrating Example 6 of the construction of the heat transfer suppression component according to an embodiment of the present invention. Figure 20 It is shown Figure 19 The accompanying photograph shows alternative images of other areas of the insulation material. Additionally, Figure 21 It is shown Figure 19 and Figure 20 The accompanying photograph shows a cross-section of the insulation material. Figures 19-21 In the construction example 6 shown, for the relationship with Figures 14-16 The components shown in Example 4 of the insulation material construction are labeled with the same symbols, and detailed descriptions are omitted. It should be noted that... Figures 19-21 The insulation material 90 shown can be used, for example, as a heat insulation material. Figure 1A , Figure 1B , Figure 3 , Figure 4 The heat transfer suppression components 50, 120, and 130 shown have thermal insulation material 10. Figure 5A , Figure 5B , Figure 6 , Figure 7 The heat transfer suppression components 140, 150, and 160 shown include a first thermal insulation material 10a and a second thermal insulation material 10b.

[0182] like Figure 19 As shown, the thermal insulation material 90 comprises inorganic particles 4 and organic fibers 1. Furthermore, at least a portion of the organic fibers 1 has a branched structure consisting of a base 32 and branches 33 extending from the base 32. In this embodiment, the branches 3 extend from the base 32 in four directions: direction D1, direction D2, direction D3, and direction D4. A framework is formed by the base 32 and the plurality of branches 33.

[0183] In addition, Figure 20 In other regions of the insulation material 90 shown, organic fibers 1 also include a branched structure consisting of a base 32 and branches 33 extending from the base 32. It should be noted that... Figure 20 The organic fiber 1 shown has a base 32 and branches 33 extending from the base 32 in five directions: direction D1, direction D2, direction D3, direction D4, and direction D5. The base 32 is thicker than the multiple branches 33.

[0184] Furthermore, such as Figure 19 and Figure 20As shown, in this embodiment, inorganic particles 4 are fused onto the surface of the organic fiber 1, thereby creating a structure in which the surface of the organic fiber 1 is covered by inorganic particles 4.

[0185] In addition, such as Figure 21 As shown in the cross-sectional view, a plurality of pores 7 are formed in the thermal insulation material 90. Furthermore, in the thermal insulation material 90, at least a portion of multiple organic fibers 1 are fused together to form a fiber bundle 6, and voids 8 are formed between the multiple organic fibers 1 constituting the fiber bundle 6. It should be noted that... Figure 21 In this study, it was also confirmed that the organic fiber 1 has a branched structure consisting of a base 32 and branches 33 extending from the base 32 in three directions.

[0186] Furthermore, a fiber layer 11 may be formed on at least a portion of the first and second surfaces of the insulation material 90, which are orthogonal to the thickness direction. The fiber layer 11 is formed by fusing at least a portion of multiple organic fibers 1 together, creating a layered structure on the surfaces (first and second surfaces) of the insulation material 90. Additionally, a composite layer 12 is formed between the fiber layer 11 and the base layer 13, which contains inorganic particles 4 and organic fibers 1. The composite layer 12 is a layer in which a portion of the fiber layer 11 and a portion of the inorganic particles 4 are mixed. Specifically, the composite layer 12 comprises a region containing multiple organic fibers 1 fused together and inorganic particles 4 fused to the organic fibers 1.

[0187] It should be noted that the fiber bundle 6 is formed by interweaving 10 or more organic fibers 1 and fusing the organic fibers 1 together in a portion, and is arranged in any direction inside the insulation material 90. On the other hand, the fiber layer 11 is a layer formed by assembling 10 or more organic fibers 1 on the surface of the insulation material 90, and extends in a stripe-like pattern in a direction approximately parallel to the surface.

[0188] In the insulation material 90 constructed in this way, at least a portion of the organic fiber 1 has a branched structure consisting of a base 32 and branches 33, thus the organic fiber 1 forms a skeleton and can maintain the shape of the insulation material 90. In this embodiment, the base 32 is formed by a welded portion where the organic fibers 1 are fused together. Specifically, since the base 32 is the part where a portion of multiple organic fibers 1 comes into contact and solidifies after melting together, it is thicker than the branches 33. Therefore, the entire skeleton can be firmly supported by the base 32, thus significantly improving the strength of the insulation material 90.

[0189] In the thermal insulation material 90, at least a portion of the organic fiber 1 has a branched structure consisting of a base 32 and branches 33 extending from the base 32 in at least three directions. The branched structure can be observed in cross-sectional photographs of the thermal insulation material 90, but a simpler method to confirm the branched structure is to tear the thermal insulation material 90 along a plane orthogonal to its thickness direction and observe the resulting cross-section. In this way, by observing the cross-section, the organic fiber 1 having a branched structure consisting of a base 32 and branches 33 extending from the base 32 in at least three directions can be easily confirmed. The base 32 and branches 33 will be described in more detail below.

[0190] (Base (welded section))

[0191] The welded portion is formed as follows: When using a core-sheath structure adhesive fiber as the material of the insulation material 90, at the point where multiple adhesive fibers contact each other, the sheath of the adhesive fiber is temporarily melted by heating, and then cooled, thereby forming the welded portion. If a core-sheath structure adhesive fiber is used as the material of the insulation material 90, the welded portion contains a second organic material constituting the sheath.

[0192] Thus, in the manufacturing process of the heat transfer suppression component 50, if the sheath portion in the contact area of ​​multiple adhesive fibers melts due to heating, the amount of molten sheath portion (second organic material) increases compared to the case where the sheath portion of a single adhesive fiber melts, forming a coarse weld portion (base 32) after cooling. As a result, the skeleton is firmly supported by the base 32.

[0193] (Branch)

[0194] The branch 33 extends from the base 32 in at least three directions, serving to retain the inorganic particles 4. Furthermore, since the base 32 and branch 33 form a framework, the strength of the heat transfer suppression component 50 is also improved. Thus, a high dust suppression effect can be achieved.

[0195] When using a core-sheath structure adhesive fiber as organic fiber 1, the branch 33 is part of the core-sheath structure adhesive fiber, having a core made of a first organic material and a sheath made of a second organic material.

[0196] If the branches 33 extending from the base 32 extend in at least three directions, a framework composed of organic fibers 1 can be formed. Furthermore, these multiple branches 33 preferably extend in their respective three-dimensional directions, thereby forming a three-dimensional and robust framework.

[0197] In the aforementioned heat insulation material 90, since multiple branches 33 extend from the base 32, the inorganic particles 4 can be retained by these multiple branches 33. Through the synergistic effect of the increased sheet strength resulting from the skeleton formation, a high dust suppression effect can be achieved. Therefore, for example, during the charging and discharging of battery cells 20a, 20b, and 20c, even when a portion of it expands and applies compressive stress or impact to the heat transfer suppression component, the shape of the heat insulation material 90 can be maintained by the skeleton structure of the heat insulation material 90 and the effect of the frame 53 in the heat transfer suppression component. As a result, the shedding (dust shedding) of inorganic particles 4 can be suppressed, and the reduction in heat insulation effect caused by the compressive deformation of the heat insulation material 90 can be prevented.

[0198] The mechanism by which the inorganic particles 4 can be suppressed from falling off the surface of the insulation material 90 is believed to be due to the same effect as the insulation material 60 in the above-described structural example 3, in addition to the retention effect of the inorganic particles 4 based on the branch 33. Furthermore, if the inorganic particles 4 are fused to the surface of the organic fiber 1, the organic fiber 1 has an apparent coarser fiber diameter, and therefore has a higher strength than that of the organic fiber 1 alone, and a high retention effect of the inorganic particles 4 can be obtained.

[0199] It should be noted that in the insulation material 90, there may be areas on the outer periphery of the organic fiber 1 where the inorganic particles 4 are not fused. Even in such cases, the effect of retaining the inorganic particles 4 can be fully achieved.

[0200] In addition, the thermal insulation material 90 contains highly flexible organic fibers 1, which improves the flexibility of the thermal insulation material 90. Furthermore, the organic fibers 1 are easy to intertwine with each other, which improves the strength of the sheet.

[0201] Furthermore, the insulation material 90 preferably has multiple pores 7 and gaps 8 between the multiple organic fibers 1 constituting the fiber bundle 6, thereby achieving air insulation and improving insulation performance. In addition, due to the presence of the gaps 8, the organic fibers 1 are not completely constrained, thus further improving the flexibility and strength of the insulation material 90. The gaps 8 do not need to be formed over the entire area between the multiple organic fibers 1; forming gaps 8 in at least a portion between the organic fibers 1 is sufficient to achieve a heat transfer suppression effect. It should be noted that, as shown in the first and third embodiments above, if the insulation material has gaps 54 on its main surface side, even higher insulation performance can be obtained.

[0202] Furthermore, since the insulation material 90 has fiber bundles 6 and fiber layers 11, it can achieve higher sheet strength compared to the case where organic fibers 1 are dispersed. Additionally, in the presence of the fiber layer 11, since the fiber layer 11 is not simply disposed on the base layer 13, but rather exists as a composite layer 12 between the fiber layer 11 and the base layer 13, where a portion of the fiber layer 11 is mixed with a portion of the inorganic particles 4, the fiber layer 11 is reliably constrained to the surface of the insulation material 90. Therefore, the strength of the insulation material 90 can be improved.

[0203] <Insulation Material (Structural Example 7)>

[0204] Figure 22 This is a photograph serving as a substitute for the accompanying drawing, illustrating Example 7 of the construction of the heat transfer suppression component according to an embodiment of the present invention. Figure 23 It is Figure 22 The accompanying photograph shows an enlarged portion of the insulation material. Figure 22 and Figure 23 In the construction example 7 shown, for the relationship with Figure 10 The components shown in Example 2 of the insulation material construction are labeled with the same symbols, and detailed descriptions are omitted. It should be noted that... Figure 22 and Figure 23 The insulation material 110 shown can be used, for example, as a heat insulation material. Figure 1A , Figure 1B , Figure 3 , Figure 4 The heat transfer suppression components 50, 120, and 130 shown have thermal insulation material 10. Figure 5A , Figure 5B , Figure 6 , Figure 7 The heat transfer suppression components 140, 150, and 160 shown include a first thermal insulation material 10a and a second thermal insulation material 10b.

[0205] like Figure 22 and Figure 23 As shown, the thermal insulation material 110 comprises inorganic particles 4 and organic fibers 1. A first region 42 having striped fiber bundles 47 composed of multiple organic fibers 1 and a second region 43 without fiber bundles 47 are formed on the surface of the thermal insulation material 110. In this specification, "fiber bundle 47" refers to 10 or more organic fibers 1 interwoven together, extending in a striped pattern in a direction substantially parallel to the surface of the thermal insulation material 110.

[0206] That is, when observing the surface of the insulation material 110, such as Figure 23 As shown, in the first region 42, multiple organic fibers 1 are observed to be intertwined. On the other hand, in the second region 43, there are also areas where several organic fibers 1 are observed, but fiber bundles 47 formed by multiple organic fibers 1 intertwined are not observed.

[0207] It should be noted that in this embodiment, the first region 42 and the second region 43 constitute an island structure, and the second region 43 is formed in such a way that it is surrounded by the first region 42, which is equivalent to the sea.

[0208] In the thermal insulation material 110, the fiber bundles 47 formed by the interlacing of organic fibers 1 are present in a striped pattern on the surface of the thermal insulation material 110, thus improving the strength of the thermal insulation material 110. Furthermore, since the entire surface is not covered by the fiber bundles 47, but rather has a first region 42 where the fiber bundles 47 are present and a second region where the fiber bundles 47 are absent, the flexibility of the thermal insulation material 110 is also excellent. Furthermore, in this embodiment, the thermal insulation material is formed with a thickness thinner than the frame, and the aforementioned fiber bundles 47 are present on the surface of the thermal insulation material 110. Therefore, even when impact or pressure is applied to the thermal insulation material 110, the voids on the main surface side of the thermal insulation material as shown in the first and third embodiments, the elastic material 51 as shown in the second embodiment, and the fiber bundles 47 can absorb and mitigate the impact and pressure. Therefore, the shedding (dust) of inorganic particles 4 can be suppressed, and the reduction in the thermal insulation performance of the heat transfer suppression component can be prevented.

[0209] It should be noted that in the thermal insulation material 110, the fiber bundles 47 formed by the interlacing of organic fibers 1 exist not only on the surface of the thermal insulation material 110, but also inside it. As a result, superior strength can be obtained.

[0210] The fiber bundles 47, formed in a manner extending on the surface of the insulation material 110, are preferably of a relatively long length. Figure 24 An example of a method for defining the length of the fiber bundle 47 will be described.

[0211] like Figure 24 As shown, rectangular imaginary frames 21 are arranged along striped fiber bundles 47 on the surface of the insulation material 110. In this embodiment, the imaginary frames 21 are 5 mm square and arranged continuously from one another. If there are fiber bundles 47 penetrating at least three consecutive imaginary frames 21, it can be determined that the insulation material 110 has a sufficient effect on improving its strength.

[0212] Alternatively, the length of the fiber bundles 47 extending in a striped pattern can be easily measured. For example, a method can be used to arrange a thin rope or the like along the fiber bundles 47 on the surface of the insulation material 110, and then measure the length of the rope. When measuring the length of continuous fiber bundles 47, if there are fiber bundles 47 with a length of 20 mm or more, the effect of improving the strength of the insulation material 110 can be sufficiently obtained.

[0213] Furthermore, such as Figure 25 As shown, if the fiber bundles 47 are connected in a mesh pattern on the surface of the insulation material 110, the sheet strength can be further improved.

[0214] The following provides a more detailed description of the materials constituting the insulation materials of the above-described structural examples 1 to 7 and their preferred contents.

[0215] <Organic Fiber>

[0216] Organic fiber 1 imparts flexibility to the insulation material, and inorganic particles 4 and other organic fibers 1 are fused to its surface, thereby maintaining the strength and shape of the sheet. Single-component organic fibers can also be used as the material for the organic fiber 1 in the insulation material, but core-sheath structure adhesive fibers are preferred. The core-sheath structure adhesive fiber has a core extending along the length of the fiber and a sheath formed to cover the outer peripheral surface of the core. Furthermore, the core is composed of a first organic material, and the sheath is composed of a second organic material, the first organic material having a higher melting point than the second organic material. When using a core-sheath structure adhesive fiber as the material, in the aforementioned insulation material, the core is equivalent to organic fiber 1. Additionally, during the manufacture of the insulation material, the second organic material constituting the sheath is melted and then solidified again; therefore, in the insulation material, the sheath becomes the welded portion 5.

[0217] When using a core-sheath structure adhesive fiber as the material of organic fiber 1, there is no particular limitation as long as the melting point of the core, i.e., the first organic material constituting organic fiber 1, is higher than that of the sheath, i.e., the second organic material, which exists on the outer periphery of organic fiber 1. Examples of the first organic material include at least one selected from polyethylene terephthalate, polypropylene, and nylon.

[0218] (Organic fiber content)

[0219] In this embodiment, if the content of organic fiber 1 in the insulation material is properly controlled, the reinforcement effect of the skeleton can be fully obtained.

[0220] The content of organic fiber 1 is preferably 2% by mass or more, and more preferably 4% by mass or more, relative to the total mass of the insulation material. In addition, if the content of organic fiber 1 is too high, the content of inorganic particles 4 will be relatively reduced. Therefore, in order to obtain the desired insulation performance, the content of organic fiber is preferably 10% by mass or less, and more preferably 8% by mass or less, relative to the total mass of the insulation material.

[0221] (Fiber length of organic fibers)

[0222] There is no particular limitation on the fiber length of organic fiber 1. However, from the perspective of ensuring formability and processability, the average fiber length of organic fiber is preferably less than 10 mm.

[0223] On the other hand, from the perspective of enabling the organic fiber 1 to function as a skeleton and ensuring the compressive strength of the insulation material, the average fiber length of the organic fiber 1 is preferably 0.5 mm or more.

[0224] <Welding section>

[0225] The welded portion 5 is formed by heating and temporarily melting the surface of the organic fiber 1 or the sheath of the adhesive fiber with a core-sheath structure, followed by cooling, so that the inorganic particles 4 are welded to the surface of the organic fiber 1, and the organic fibers 1 are welded to each other. When the adhesive fiber with a core-sheath structure is used as the material of the organic fiber 1, the welded portion 5 contains a second organic material constituting the sheath.

[0226] (Second Organic Material)

[0227] The second organic material is not particularly limited as long as its melting point is lower than that of the first organic material constituting the organic fiber 1 described above. Examples of the second organic material include at least one selected from polyethylene terephthalate, polyethylene, polypropylene, and nylon.

[0228] It should be noted that the melting point of the second organic material is preferably 90°C or higher, more preferably 100°C or higher. Furthermore, the melting point of the second organic material is preferably 150°C or lower, more preferably 130°C or lower.

[0229] <Inorganic Particles>

[0230] As inorganic particles, a single inorganic particle can be used, or two or more inorganic particles can be used in combination. Regarding the type of inorganic particle, from the perspective of heat transfer suppression effect, particles composed of at least one inorganic material selected from oxide particles, carbide particles, nitride particles, and inorganic hydrate particles are preferred, with oxide particles being more preferred. Furthermore, there are no particular limitations on the shape; it is preferable to include at least one selected from nanoparticles, hollow particles, and porous particles. Specifically, inorganic hollow spheres such as silica nanoparticles, metal oxide particles, microporous particles, and hollow silica particles, particles composed of thermally expandable inorganic materials, and particles composed of hydrous porous bodies can also be used.

[0231] If the average secondary particle size of the inorganic particles is 0.01 μm or more, it is readily available, which can suppress the increase in manufacturing costs. Furthermore, if the average secondary particle size is 200 μm or less, the desired heat insulation effect can be obtained. Therefore, the average secondary particle size of the inorganic particles is preferably 0.01 μm or more and 200 μm or less, more preferably 0.05 μm or more and 100 μm or less.

[0232] It should be noted that combining two or more types of inorganic particles with different heat transfer inhibition effects allows for multi-stage cooling of the exothermic body, resulting in endothermic effects over a wider temperature range. Specifically, it is preferable to use a mixture of large-diameter and small-diameter particles. For example, if nanoparticles are used as one type of inorganic particle, the other type of inorganic particle preferably includes inorganic particles composed of metal oxides. Hereinafter, small-diameter inorganic particles will be used as the first type of inorganic particle, and large-diameter inorganic particles will be used as the second type of inorganic particle, for further detailed explanation.

[0233] <First Inorganic Particle>

[0234] (Oxide particles)

[0235] Oxide particles have a high refractive index, resulting in strong diffuse reflection of light. Therefore, when oxide particles are used as the first inorganic particle, they can suppress radiative heat transfer, especially in high-temperature regions such as those with abnormal heat dissipation. As oxide particles, at least one particle selected from silicon dioxide, titanium dioxide, zircon, barium titanate, zinc oxide, and aluminum oxide can be used. That is, only one of the aforementioned oxide particles that can be used as inorganic particles can be used, or two or more oxide particles can be used. In particular, silicon dioxide is a component with high thermal insulation properties, and titanium dioxide is a component with a higher refractive index than other metal oxides. Both are highly effective at diffuse reflection of light and shielding from radiative heat in high-temperature regions above 500°C. Therefore, silicon dioxide and titanium dioxide are the most preferred oxide particles.

[0236] (Average primary particle size of oxide particles: ≥0.001μm ≤50μm)

[0237] The particle size of oxide particles can sometimes affect the effectiveness of reflecting radiant heat. Therefore, if the average primary particle size is limited to a specified range, higher thermal insulation can be achieved.

[0238] That is, if the average primary particle size of the oxide particles is greater than 0.001 μm, it is sufficiently larger than the wavelength of light that helps to heat up, so that the light can be diffusely reflected efficiently. Therefore, in high temperature regions above 500°C, the radiative heat transfer of heat in the insulation material can be suppressed, and the insulation performance can be further improved.

[0239] On the other hand, if the average primary particle size of the oxide particles is less than 50 μm, even if they are compressed, the number of joints between the particles will not increase, making it difficult to form a path for heat conduction. Therefore, it is particularly effective in reducing the impact on insulation performance in the normal temperature range where heat conduction is dominant.

[0240] It should be noted that, in this invention, the average primary particle size can be obtained by observing the particles under a microscope, comparing them with a standard scale, and taking the average of any 10 particles.

[0241] (Nanoparticles)

[0242] In this invention, "nanoparticles" refers to nanoscale particles with an average primary diameter of less than 1 μm that are spherical or nearly spherical. Because nanoparticles are low-density, they can suppress conductive heat transfer. If nanoparticles are used as the first inorganic particle, the three-dimensionally linked pores 7 are further miniaturized, thus achieving excellent thermal insulation by suppressing convective heat transfer. Therefore, when used in batteries within normal ambient temperature ranges, thermal conduction between adjacent nanoparticles can be suppressed; from this perspective, the use of nanoparticles is preferred.

[0243] Furthermore, if nanoparticles with small average primary particle size are used as oxide particles, the increase in thermal conductivity of the insulation material can be suppressed even when the insulation material is compressed due to expansion associated with thermal runaway of the battery cell, resulting in an increase in internal density. This is believed to be because nanoparticles easily form small gaps between particles through electrostatic repulsion, resulting in low packing density, thus filling the gaps in a buffering manner.

[0244] It should be noted that in this invention, when using nanoparticles as the first inorganic particle, there are no particular limitations on the material as long as they meet the above definition of nanoparticles. For example, silica nanoparticles are highly insulating materials, and the contact points between the particles are small; therefore, the heat conducted through silica nanoparticles is less than when using silica particles with larger particle sizes. Furthermore, the bulk density of silica nanoparticles typically obtained is 0.1 g / cm³. 3 Therefore, even if the battery cells disposed on both sides of the heat insulation material undergo thermal expansion, applying significant compressive stress to the heat insulation material, the size (area) and number of the contact points between the silica nanoparticles will not increase significantly, thus maintaining heat insulation performance. Therefore, silica nanoparticles are preferably used as the nanoparticles. Examples of silica nanoparticles include wet silica, dry silica, and aerogels; the silica nanoparticles particularly suitable for this embodiment will be described below.

[0245] Typically, wet silica particles agglomerate, while dry silica particles can be dispersed. In the temperature range below 300°C, conduction dominates heat transfer; therefore, dry silica, which can disperse particles, provides superior thermal insulation performance compared to wet silica.

[0246] It should be noted that the thermal insulation material of this embodiment is preferably manufactured using a method that processes a mixture of materials into sheets using a dry process. Therefore, as inorganic particles, dry silica, silica aerogel, or the like with low thermal conductivity is preferred.

[0247] (Average primary particle size of nanoparticles: 1 nm to 100 nm)

[0248] If the average primary particle size of the nanoparticles is limited to a specified range, higher thermal insulation performance can be obtained.

[0249] That is, if the average primary particle size of the nanoparticles is between 1 nm and 100 nm, especially in the temperature range below 500 °C, convective and conductive heat transfer within the insulation material can be suppressed, thereby further improving the insulation performance. In addition, even under compressive stress, the voids remaining between the nanoparticles and the numerous junctions between particles can suppress conductive heat transfer and maintain the insulation performance of the insulation material.

[0250] It should be noted that the average primary particle size of the nanoparticles is more preferably 2 nm or more, and even more preferably 3 nm or more. On the other hand, the average primary particle size of the nanoparticles is more preferably 50 nm or less, and even more preferably 10 nm or less.

[0251] (Inorganic hydrate particles)

[0252] When inorganic hydrate particles are heated by an exothermic body and reach a temperature above the thermal decomposition initiation temperature, they undergo thermal decomposition, releasing their own water of crystallization and thus lowering the temperature of the exothermic body and its surroundings, exhibiting what is known as "endothermic effect." Furthermore, after releasing the water of crystallization, they become porous, exhibiting a thermal insulating effect through numerous air pores.

[0253] Specific examples of inorganic hydrates include aluminum hydroxide (Al(OH)3), magnesium hydroxide (Mg(OH)2), calcium hydroxide (Ca(OH)2), zinc hydroxide (Zn(OH)2), iron hydroxide (Fe(OH)2), manganese hydroxide (Mn(OH)2), zirconium hydroxide (Zr(OH)2), and gallium hydroxide (Ga(OH)3).

[0254] For example, aluminum hydroxide contains approximately 35% water of crystallization, as shown in the following formula. It undergoes thermal decomposition to release this water of crystallization, exhibiting an endothermic effect. Furthermore, after releasing the water of crystallization, it transforms into alumina (Al₂O₃), a porous material, which functions as a thermal insulation material.

[0255]

[0256] It should be noted that the heat transfer suppression component 50 of this embodiment is suitable for being sandwiched between battery cells, but in a battery cell where thermal runaway has occurred, the temperature rises sharply to over 200°C and continues to rise to around 700°C. Therefore, as inorganic particles, it is preferable to use inorganic hydrates with a thermal decomposition initiation temperature of 200°C or higher.

[0257] Regarding the thermal decomposition initiation temperatures of the inorganic hydrates listed above, aluminum hydroxide is approximately 200°C, magnesium hydroxide is approximately 330°C, calcium hydroxide is approximately 580°C, zinc hydroxide is approximately 200°C, iron hydroxide is approximately 350°C, manganese hydroxide is approximately 300°C, zirconium hydroxide is approximately 300°C, and gallium hydroxide is approximately 300°C. These temperatures largely overlap with the temperature range of a rapidly rising battery cell that has experienced thermal runaway, effectively suppressing the temperature rise. Therefore, these inorganic hydrates can be considered preferred.

[0258] (Average secondary particle size of inorganic hydrate particles: ≥0.01μm ≤200μm)

[0259] Furthermore, when inorganic hydrate particles are used as the first inorganic particles, if their average particle size is too large, the first inorganic particles (inorganic hydrates) located near the center of the insulation material will require a certain amount of time before reaching their thermal decomposition temperature. Therefore, there is a possibility that the first inorganic particles near the center of the sheet may not be completely thermally decomposed. Therefore, the average secondary particle size of the inorganic hydrate particles is preferably 0.01 μm to 200 μm, more preferably 0.05 μm to 100 μm.

[0260] (Particles composed of thermally expanding inorganic materials)

[0261] Examples of thermally expandable inorganic materials include vermiculite, bentonite, mica, and perlite.

[0262] (Particles composed of hydrous porous materials)

[0263] Specific examples of hydrous porous materials include zeolite, kaolin, montmorillonite, acid clay, diatomaceous earth, wet silica, dry silica, aerogel, mica, vermiculite, etc.

[0264] (Inorganic hollow sphere)

[0265] The thermal insulation material used in this invention may contain inorganic hollow spheres as the first inorganic particles.

[0266] If it contains inorganic hollow spheres, it can suppress convective or conductive heat transfer within the insulation material in temperature ranges below 500°C, thereby further improving the insulation performance of the insulation material.

[0267] As an inorganic hollow sphere, at least one selected from volcanic ash hollow spheres, silica hollow spheres, fly ash hollow spheres, barite hollow spheres, and glass hollow spheres can be used.

[0268] (Inorganic hollow sphere content: less than 60% by mass relative to the total mass of the insulation material)

[0269] The content of inorganic hollow spheres is preferably less than 60% by mass relative to the total mass of the insulation material.

[0270] (Average particle size of inorganic hollow spheres: ≥1μm ≤100μm)

[0271] The average particle size of the inorganic hollow spheres is preferably between 1 μm and 100 μm.

[0272] <Second Inorganic Particles>

[0273] When the insulation material contains two types of inorganic particles, there are no particular limitations on the second inorganic particle, as long as its material, particle size, etc., differ from the first inorganic particle. As the second inorganic particle, it can be made of inorganic hollow spheres such as oxide particles, carbide particles, nitride particles, inorganic hydrate particles, silica nanoparticles, metal oxide particles, microporous particles, and hollow silica particles; particles composed of thermally expandable inorganic materials; particles composed of hydrous porous bodies; etc. Details regarding these are as described above.

[0274] It should be noted that nanoparticles have extremely low thermal conductivity and maintain excellent thermal insulation even when compressive stress is applied to the insulation material. Furthermore, metal oxide particles such as titanium dioxide are highly effective at shielding radiant heat. In addition, when using both large-diameter and small-diameter inorganic particles, the small-diameter particles intersect within the gaps between the large-diameter particles, resulting in a denser structure that improves heat transfer suppression. Therefore, when using, for example, nanoparticles as the first inorganic particle, it is preferable to further include particles composed of metal oxides with a particle size larger than the first inorganic particles as the second inorganic particle.

[0275] Examples of metal oxides include silicon dioxide, titanium dioxide, aluminum oxide, barium titanate, zinc oxide, zircon, and zirconium oxide. In particular, titanium dioxide has a higher refractive index than other metal oxides, and it is highly effective in diffusely reflecting light and shielding radiant heat in high-temperature regions above 500°C. Therefore, titanium dioxide is the preferred choice.

[0276] When using at least one particle selected from dry silica particles and silica aerogel as the first inorganic particle, and using at least one particle selected from titanium dioxide, zircon, zirconium oxide, silicon carbide, zinc oxide, and alumina as the second inorganic particle, in order to obtain excellent thermal insulation performance in a temperature range below 300°C, the first inorganic particle preferably accounts for 50% or more, more preferably 60% or more, and even more preferably 70% or more of the total mass of inorganic particles. Furthermore, the first inorganic particle preferably accounts for 95% or less, more preferably 90% or less, and even more preferably 80% or less of the total mass of inorganic particles.

[0277] On the other hand, in order to obtain excellent thermal insulation performance in a temperature range exceeding 300°C, the second inorganic particles are preferably 5% or more by mass relative to the total mass of the inorganic particles, more preferably 10% or more by mass, and even more preferably 20% or more by mass. Furthermore, the second inorganic particles are preferably 50% or less by mass relative to the total mass of the inorganic particles, more preferably 40% or less by mass, and even more preferably 30% or less by mass.

[0278] (Average primary particle size of the second inorganic particle)

[0279] When the insulation material contains second inorganic particles composed of metal oxides, if the average primary particle size of the second inorganic particles is 1 μm or more and 50 μm or less, radiative heat transfer can be effectively suppressed in high-temperature regions above 500°C. The average primary particle size of the second inorganic particles is further preferably 5 μm or more and 30 μm or less, and most preferably 10 μm or less.

[0280] (Content of inorganic particles)

[0281] In this embodiment, if the total content of inorganic particles 4 in the insulation material is properly controlled, the insulation performance of the insulation material can be fully ensured.

[0282] The total content of inorganic particles 4 is preferably 60% by mass or more, and more preferably 70% by mass or more, relative to the total mass of the insulation material. In addition, if the total content of inorganic particles 4 is too high, the content of organic fibers will be relatively reduced. Therefore, in order to fully obtain the reinforcing effect of the skeleton and the retention effect of inorganic particles, the total content of inorganic particles 4 is preferably 95% by mass or less, and more preferably 90% by mass or less, relative to the total mass of the insulation material.

[0283] It should be noted that the content of inorganic particles 4 in the insulation material can be calculated, for example, by heating the insulation material at 800°C to decompose the organic components and then measuring the mass of the remaining part.

[0284] <Inorganic Fibers>

[0285] As inorganic fiber 15, a single inorganic fiber can be used, or two or more inorganic fibers can be used in combination. Examples of inorganic fibers include silica fiber, alumina fiber, aluminosilicate fiber, zirconium oxide fiber, carbon fiber, soluble fiber, refractory ceramic fiber, aerogel composite material, magnesium silicate fiber, alkaline earth silicate fiber, potassium titanate fiber, silicon carbide fiber, potassium titanate whisker fiber and other ceramic fibers, glass fiber, glass wool, slag wool and other glass fibers, as well as mineral fibers other than these, such as rock wool, basalt fiber, mullite fiber, and natural mineral fibers other than the above-mentioned mineral fibers.

[0286] These inorganic fibers are preferred in terms of heat resistance, strength, and ease of acquisition. Among inorganic fibers, silica-alumina fibers, alumina fibers, silica fibers, rock wool, alkaline earth silicate fibers, and glass fibers are particularly preferred in terms of processability.

[0287] There are no particular limitations on the cross-sectional shape of inorganic fibers; examples include circular cross-sections, flat cross-sections, hollow cross-sections, polygonal cross-sections, and core cross-sections. Among these, irregularly shaped fibers with hollow, flat, or polygonal cross-sections can slightly improve thermal insulation and are therefore suitable for use.

[0288] The preferred lower limit for the average fiber length of inorganic fibers is 0.1 mm, and more preferably 0.5 mm. Conversely, the preferred upper limit for the average fiber length of inorganic fibers is 50 mm, and more preferably 10 mm. If the average fiber length of inorganic fibers is less than 0.1 mm, it is difficult for the inorganic fibers to entangle with each other, which may reduce the mechanical strength of the insulation material. On the other hand, if the average fiber length of inorganic fibers is greater than 50 mm, although a reinforcing effect can be obtained, the inorganic fibers cannot be tightly entangled with each other, or may be rolled up from a single inorganic fiber, which easily creates continuous gaps and may therefore lead to a reduction in insulation performance.

[0289] The preferred lower limit for the average fiber diameter of inorganic fibers is 1 μm, more preferably 2 μm, and even more preferably 3 μm. Conversely, the preferred upper limit for the average fiber diameter of inorganic fibers is 15 μm, more preferably 10 μm. If the average fiber diameter of the inorganic fibers is less than 1 μm, the mechanical strength of the inorganic fibers themselves may decrease. Furthermore, from the viewpoint of impact on human health, the average fiber diameter of the inorganic fibers is preferably 3 μm or more. On the other hand, if the average fiber diameter of the inorganic fibers is greater than 15 μm, the solid-state heat transfer using the inorganic fibers as a medium may increase, leading to a decrease in thermal insulation performance, and the formability and strength of the insulation material may deteriorate.

[0290] (Inorganic fiber content)

[0291] In this embodiment, when the insulation material contains inorganic fibers, the content of inorganic fibers is preferably 3% by mass or more and 15% by mass or less relative to the total mass of the insulation material.

[0292] Furthermore, the content of inorganic fibers relative to the total mass of the insulation material is more preferably 5% to 10% by mass. With such a content, the shape retention, compression resistance, wind pressure resistance, and inorganic particle retention capabilities based on inorganic fibers can be well balanced. Additionally, by appropriately controlling the content of inorganic fibers, the organic fibers 1 and inorganic fibers intertwine to form a three-dimensional network, thus further improving the retention of inorganic particles 4 and other compounding materials described later.

[0293] <Other ingredients>

[0294] It should be noted that the insulation material of this embodiment may further contain binders, colorants, etc., as needed. These are useful for purposes such as strengthening the insulation material and improving its formability, and are preferably 10% or less by mass relative to the total mass of the insulation material.

[0295] The above describes the construction examples 1 to 7 of the thermal insulation material. However, the construction of the thermal insulation material containing inorganic particles and organic fibers is not limited to this, and thermal insulation materials with various constructions can be used. In particular, the thermal insulation materials of the above-described construction examples 1 to 7 have superior thermal insulation effects compared with other thermal insulation materials and thermal insulation materials containing fibers and aerogels.

[0296] Here, we explain the results of comparing the thermal insulation effects of various insulation materials with different types and thicknesses. The thermal insulation effect test can be conducted as follows: a heater is placed in contact with one main surface of the insulation material, and a thermometer is placed on the other main surface. The temperature change of the other main surface is measured as the temperature of the heater is increased. If the heater temperature is increased to 800°C, the temperature of the other main surface of the insulation material reaches its maximum after a certain period of time. At this point, it can be determined that the insulation material with the lower maximum temperature has superior thermal insulation performance. The comparison results of the thermal insulation effects are shown in Table 1 below.

[0297] [Table 1]

[0298] In Table 1 above, insulation materials A-1 and A-2 are... Figures 11-13The insulation material in Example 3 shown is obtained by dry molding organic fibers and inorganic particles with a core-sheath structure into a sheet shape. In insulation materials A-1 and A-2, the organic fibers used are core-sheath organic fibers with a core and sheath composed of polyethylene terephthalate, and whose melting points differ by more than 90°C. The inorganic particles used are silica nanoparticles and titanium dioxide. Insulation material B is a material with a fiber skeleton impregnated with SiO2.

[0299] As shown in Table 1 above, the thermal insulation performance of insulation material A-1 with a thickness of 2.0 mm is equal to that of insulation material B with a thickness of 4.5 mm. Furthermore, by further increasing the thickness of insulation material A-2, i.e., the insulation material itself, it is possible to obtain higher thermal insulation performance than insulation material B with a thinner thickness.

[0300] These results are not limited to the above-described construction example 3; the same thermal insulation performance can be obtained using all the thermal insulation materials of construction examples 1 to 7. Therefore, when using the thermal insulation materials of construction examples 1 to 7, which contain inorganic particles and organic fibers, the thickness of the thermal insulation material can be easily made thinner than the frame 53, thus making it suitable as a thermal insulation material for use as a heat transfer suppression component in the above-described embodiments of the present invention.

[0301] Furthermore, regarding the heat transfer suppression component of this embodiment, the constituent materials other than the frame, partition wall, and insulation material will be described below.

[0302] <membrane>

[0303] As described in the first to third embodiments above, when the heat transfer suppression component has a membrane 52, the material constituting the membrane 52 can be selected from at least one of polyethylene, polypropylene, polystyrene, vinyl chloride, nylon, acrylic acid, epoxy resin, polyurethane, polyetheretherketone, polyetherimide, polyethylene terephthalate, polytetrafluoroethylene (PTFE), polyphenylene sulfide, polycarbonate, and aromatic polyamide.

[0304] It should be noted that shrink packaging can also be used when the film only covers the insulation material, and when the film 52 covers the insulation material and the frame, or the entire surface of the laminate and the frame. Suitable materials for shrink packaging include polyethylene, polypropylene, polystyrene, polyethylene terephthalate, and vinyl chloride.

[0305] (Membrane thickness)

[0306] The membrane has the effect of preventing particles and the like from falling off the insulation material and preventing the insulation material from falling off the frame 53, therefore, it is preferable to have an appropriate thickness. In addition, the membrane preferably has appropriate flexibility. If the membrane thickness exceeds 1 mm, the membrane is prone to cracking and rupture. Therefore, the membrane thickness is preferably 1 mm or less, more preferably 0.1 mm or less, and even more preferably 0.05 mm or less.

[0307] On the other hand, there is no particular limitation on the lower limit of the film thickness. In order to prevent easy breakage due to friction with battery cells, etc., and to obtain the desired strength, it is preferably 0.005 mm or more, and more preferably 0.01 mm or more.

[0308] (Other materials contained in the membrane)

[0309] Furthermore, the membrane is required to withstand the high temperatures of the battery cells 20a, 20b, and 20c, therefore it is preferably flame-retardant. Specifically, it is preferable to include inorganic materials or flame-retardant materials. Examples of other materials included in the membrane include, as inorganic materials, talc, calcium carbonate, aluminum hydroxide, titanium dioxide, vermiculite, zeolite, synthetic silica, zirconium oxide, zircon, barium titanate, zinc oxide, and aluminum oxide; and as flame-retardant materials, examples include brominated flame retardants, chlorinated flame retardants, phosphorus flame retardants, boron flame retardants, silicone flame retardants, and nitrogen-containing compounds.

[0310] <Elastic Material>

[0311] The elastic material is a material that is processed into a sheet shape. As shown in the second and third embodiments described above, when the heat transfer suppression component has an elastic material 51, known materials can be used as the elastic material constituting the elastic material 51. Specifically, a sheet formed of rubber or thermoplastic elastomer that has elasticity that can be flexibly deformed relative to the deformation of the battery cells 20a, 20b, and 20c can be used.

[0312] Rubber can be either synthetic rubber or natural rubber. Examples of synthetic rubber include styrene-butadiene rubber, butadiene rubber, chloroprene rubber, isoprene rubber, butyl rubber, ethylene propylene rubber, nitrile rubber, silicone rubber, fluororubber, acrylic rubber, polyurethane rubber, polysulfide rubber, epichlorohydrin rubber, and foamed silicone rubber.

[0313] Examples of thermoplastic elastomers include various thermoplastic elastomers based on polystyrene, polyolefins, vinyl chloride, polyurethane, polyester, polyamide, and polybutadiene. Furthermore, the elastomer can be either porous or non-porous. It should be noted that, in the case of a porous elastomer, the bubble structure can be either independent bubble type or interconnected bubble type.

[0314] (Dimensions of the elastic material)

[0315] There is no particular limitation on the thickness of the elastic material, but in order to effectively obtain the effect of the elastic material, it is preferred to be more than 1 mm and less than 10 mm.

[0316] [Manufacturing method for heat transfer suppression components]

[0317] Regarding the manufacturing method of the heat transfer suppression component in this embodiment, the following section specifically focuses on... Figure 10 The example of the heat insulation material 40 shown in Example 2 being applied to the heat transfer suppression component 130 of the third embodiment will be described in detail.

[0318] Manufacturing of thermal insulation materials

[0319] For example, an adhesive fiber (not shown), inorganic particles 4, and inorganic fiber 15 with a core-sheath structure are fed into a mixer such as a V-type mixer in a specified ratio to produce a mixture.

[0320] It should be noted that, as described above, the adhesive fiber preferably uses a core-sheath structure having a core made of a first organic material and a sheath made of a second organic material. In this case, the melting point of the first organic material is higher than that of the second organic material.

[0321] The resulting mixture is then placed into a pre-designed mold and pressurized using a press or similar device. The resulting molded body is then heated, causing the sheath of the adhesive fibers to melt. The heated molded body is then cooled, causing the second organic material constituting the molten sheath to fuse with the inorganic particles 4 surrounding the adhesive fibers to the core (organic fiber 1), and also to fuse with each other in the areas where the adhesive fibers are in contact. This allows for the production of a sheet-like thermal insulation material 40 with a thickness thinner than the frame.

[0322] It should be noted that the manufacturing method for thermal insulation materials that do not contain inorganic fibers 15 can be the same as that for thermal insulation material 40. The use of inorganic fibers 15 can be arbitrarily selected.

[0323] It should be noted that when the above-mentioned insulation materials are mixed, pressurized, and heated, the interwoven organic fibers 1 exposed on the surface are heated and formed on the surface of the insulation material 40 in the form of a fiber layer 11. The resulting fiber layer 11 has the effect of improving the strength of the insulation material 40 and mitigating the impact on the surface of the insulation material 40.

[0324] <Assembly of Layered Structures>

[0325] Then, an elastic material 51 is placed on the main surface of the insulation material 40, and the two are fixed together. There are no particular limitations on the method for fixing the insulation material 40 and the elastic material 51 to each other; various methods can be used, such as bonding with adhesives, sewing with thread, clamping and fixing with clamps, covering with a film, or heating and fixing the film after covering with a thermocompressible film. It should be noted that the elastic material 51 does not necessarily need to be layered; as shown in the first embodiment, only the insulation material can be used.

[0326] <Frame Manufacturing>

[0327] Additionally, a frame 53 is fabricated to surround the outer perimeter of the insulation material. The frame 53 can be made of materials such as resin, and can be a single-piece molded material or fabricated by combining multiple frame components. Figure 5A and Figure 5B As shown in the fourth embodiment and its variations, when the heat transfer suppression component has a partition wall, the frame and the partition wall can be integrally formed or made by combining multiple components.

[0328] <Assembly of stacked bodies into frames>

[0329] Then, the insulation material is fitted into and fixed to the frame 53. There are no particular limitations on the method of fixing the insulation material to the frame 53. It can be fixed by using fixing materials such as adhesives, or by machining grooves on the frame 53 to fix it by embedding it into grooves.

[0330] <Membrane Application>

[0331] Next, prepare two films 52 that have approximately the same outer diameter as the frame 53 when viewed from above, overlap the films 52 with the frame 53, and thermally fuse the frame 53 and the films 52 together. In this way, the films 52 can be thermally fused to the frame 53, can completely surround the frame 53 and the insulation material, or can only surround the insulation material. Alternatively, as shown in the fourth embodiment, the films 52 can be omitted.

[0332] It should be noted that the outer diameter of the frame 53 and the size of the membrane 52 are "approximately the same" means that the difference between the two sizes is allowed to be ±5%, preferably ±3%, and more preferably ±1% of the average value of the two.

[0333] The aforementioned thermal insulation material is preferably manufactured using a dry process. When using a dry process, inorganic particles 4 suitable for the dry process are used, and solvents such as water, which are required for molding using a wet process, are not added to the mixture. However, during the manufacture of the thermal insulation material, in order to prevent the inorganic particles 4 and other powders from flying around and making the handling of raw materials difficult, a small amount of solvent such as water may be added within the range considered to be part of a dry process. For example, by adding a small amount of solvent such as water to the mixture, the dispersion of inorganic particles during manufacturing can be suppressed.

[0334] Next, the preferred adhesive fibers, heating conditions, and other adhesive materials used in the manufacture of the above-mentioned thermal insulation material will be described.

[0335] <Adhesive Fibers>

[0336] When using adhesive fiber 3 in a core-sheath structure as the material for the thermal insulation material, there are no particular limitations as long as the melting point of the first organic material constituting the core is higher than that of the second organic material constituting the sheath. The first organic material constituting the core can be at least one selected from polyethylene terephthalate, polypropylene, and nylon. Furthermore, the second organic material constituting the sheath can be at least one selected from polyethylene terephthalate, polyethylene, polypropylene, and nylon.

[0337] If the melting point of the first organic material constituting the core is sufficiently higher than the melting point of the second organic material constituting the sheath, the temperature setting margin in the heating process can be expanded, and the temperature setting for obtaining the desired structure can be more easily achieved. For example, the melting point of the first organic material is preferably 60°C or more higher than the melting point of the second organic material, more preferably 70°C or more higher, and even more preferably 80°C or more higher.

[0338] It should be noted that the adhesive fibers 3 with core-sheath structures described above are generally commercially available, and the materials constituting the core and sheath can be the same or different. Examples of adhesive fibers with the same core and sheath material but different melting points include fibers with a core and sheath made of polyethylene terephthalate, fibers made of polypropylene, and fibers made of nylon. Examples of adhesive fibers with different core and sheath materials include fibers with a core made of polyethylene terephthalate and a sheath made of polyethylene; fibers with a core made of polypropylene and a sheath made of polyethylene; and so on.

[0339] In this embodiment, the melting point of the second organic material constituting the sheath of the adhesive fiber 3 represents the melting temperature at which the second organic material begins to melt and deform. Softening accompanied by shape change is also judged as a type of melting and deformation. The melting point of the sheath of the adhesive fiber can be determined, for example, by the following method.

[0340] The adhesive fiber, which is the object of the test, is arranged in a manner that connects it to a glass fiber with a higher melting point. It is heated from room temperature to, for example, 200°C at a heating rate of 5°C / min, and then cooled to room temperature. If the surface of the adhesive fiber undergoes melting deformation and fusion occurs at the point where it connects to the glass fiber, or if the cross-sectional shape of the adhesive fiber changes, it can be determined that the melting point of the second organic material constituting the sheath is below 200°C. In this embodiment, by varying the heating temperature and observing the fusion state of the adhesive fiber and glass fiber after cooling, or the cross-sectional shape of the adhesive fiber, using the above method, the melting point of the second organic material constituting the sheath can be determined.

[0341] (Content of adhesive fibers)

[0342] When using adhesive fiber 3 with a core-sheath structure as the material for thermal insulation, if the content of adhesive fiber in the mixture is properly controlled, the reinforcement effect of the skeleton can be fully obtained in the resulting thermal insulation.

[0343] The content of adhesive fiber 3 relative to the total mass of the mixture is preferably 5% by mass or more, more preferably 10% by mass or more. In addition, if the content of adhesive fiber is too high, the content of inorganic particles 4 will be relatively reduced. Therefore, in order to obtain the desired thermal insulation performance, the content of adhesive fiber 3 relative to the total mass of the mixture is preferably 25% by mass or less, more preferably 20% by mass or less.

[0344] (Hot melt powder)

[0345] In this embodiment, in addition to the aforementioned adhesive fibers 3 and inorganic particles 4, the mixture may also contain hot-melt powder as an adhesive material. The hot-melt powder is, for example, a powder containing a third organic material different from the first and second organic materials and possessing the property of melting upon heating. By including the hot-melt powder in the mixture and heating it, the hot-melt powder melts, and upon subsequent cooling, it solidifies while still containing the surrounding inorganic particles 4. Therefore, it is possible to further suppress the detachment of the inorganic particles 4 from the insulation material.

[0346] As a hot-melt powder, various hot-melt powders with different melting points can be cited. Considering the melting points of the core and sheath of the adhesive fiber used, a hot-melt powder with an appropriate melting point can be selected. Specifically, if the melting point of the third organic material constituting the hot-melt powder is lower than that of the first organic material constituting the aforementioned organic fiber, a heating temperature can be set to melt the sheath and the hot-melt powder by leaving the core intact. For example, if the melting point of the hot-melt powder is below the melting point of the sheath, the heating temperature during manufacturing only needs to be set between the melting points of the core and the sheath, thus making it easier to set the heating temperature.

[0347] On the other hand, the type of hot-melt powder used can also be selected such that its melting point is between the melting point of the core and the melting point of the sheath. When using a hot-melt powder with such a melting point, after both the sheath and the hot-melt powder melt, upon cooling and solidification, the hot-melt powder present in the gaps between the organic fiber (core) 1 and the surrounding molten sheath, as well as the inorganic particles 4, solidifies first. As a result, the position of the organic fiber 1 can be fixed, and subsequently, by fusing the molten sheath to the organic fiber, a three-dimensional skeleton can be easily formed. Therefore, the overall strength of the sheet can be further improved.

[0348] If the melting point of the third organic material constituting the hot-melt powder is sufficiently lower than the melting point of the first organic material constituting the core, the temperature setting margin in the heating process can be expanded, and the temperature setting for obtaining the desired structure can be more easily achieved. For example, the melting point of the first organic material is preferably 60°C or more higher than the melting point of the third organic material, more preferably 70°C or more higher, and even more preferably 80°C or more higher.

[0349] It should be noted that the melting point of the hot-melt powder (third organic material) is preferably 80°C or higher, more preferably 90°C or higher. Furthermore, the melting point of the hot-melt powder (third organic material) is preferably 180°C or lower, more preferably 150°C or lower. Examples of components constituting the hot-melt powder include polyethylene, polyester, polyamide, and ethylene vinyl acetate.

[0350] (Content of hot melt powder)

[0351] To suppress the shedding of inorganic particles, even a trace amount of hot-melt powder in the mixture is sufficient to achieve the effect of suppressing powder shedding. Therefore, the content of hot-melt powder relative to the total mass of the mixture is preferably 0.5% by mass or more, and more preferably 1% by mass or more.

[0352] On the other hand, if the content of hot melt powder is increased, the content of inorganic particles 4 and the like will be relatively reduced. Therefore, in order to obtain the desired heat insulation performance, the content of hot melt powder relative to the total mass of the mixture is preferably 5% by mass or less, and more preferably 4% by mass or less.

[0353] <Heating conditions>

[0354] When using adhesive fibers with a core-sheath structure as the insulation material, it is preferable that the heating temperature in the heating process is higher than the melting point of the second organic material constituting the sheath and lower than the melting point of the first organic material constituting the core. By setting the heating temperature to such a level, as described above, the core can be used to ensure the strength of the sheet on either the surface side or the center side, and the inorganic particles 4 can be held in place by the welded portion 5.

[0355] Specifically, the heating temperature in the heating process is preferably set at least 10°C higher than the melting point of the second organic material constituting the sheath, and more preferably at least 20°C higher. On the other hand, the heating temperature is preferably set at least 10°C lower than the melting point of the first organic material constituting the core, and more preferably at least 20°C lower.

[0356] There is no particular limitation on the heating time, but it is preferable to set a heating time that allows the sheath to melt sufficiently. For example, it can be set to a time of 3 to 15 minutes.

[0357] When the material used as the insulation material includes hot-melt powder, the heating temperature in the heating process is preferably set at least 10°C higher than the higher of the melting point of the second organic material constituting the sheath and the melting point of the third organic material constituting the hot-melt powder, more preferably at least 20°C higher. On the other hand, the heating temperature is preferably set at least 10°C lower than the melting point of the first organic material constituting the core, more preferably at least 20°C lower. By setting the heating temperature to such a level, a strong skeleton can be formed, the strength of the sheet can be further improved, and the inorganic particles 4 can be prevented from falling off by means of the welded portion 5, etc.

[0358] <Thickness of thermal insulation material>

[0359] In this embodiment, the thickness of the insulation material is not particularly limited as long as it is thinner than the thickness of the frame, but is preferably 0.05 mm to 10 mm. If the thickness is 0.05 mm or more, sufficient compressive strength can be obtained. On the other hand, if the thickness is 10 mm or less, good thermal insulation properties of the heat transfer suppression component can be obtained.

[0360] [Battery Pack]

[0361] Examples of battery packs employing the heat transfer suppression component 50 of the first embodiment of the present invention are as described above. Figure 2 As illustrated. Here, the example uses... Figure 2 The composition and performance of the battery pack are explained in detail. It should be noted that, as mentioned above, Figure 2 The heat transfer suppression component 50 shown can be replaced with heat transfer suppression components 120, 130, 140, 150, 160, and other heat transfer suppression components with different structures within the scope of the present invention. Additionally, the insulation material can be replaced with the aforementioned insulation materials 10, 40, 60, 70, 80, 90, 110, and other insulation materials within the scope of the present invention, each with its own structure.

[0362] like Figure 2As shown, the battery pack 100 has multiple battery cells 20a, 20b, 20c and a heat transfer suppression component 50 according to this embodiment. These battery cells are connected in series or in parallel. For example, the heat transfer suppression component 50 is located between battery cells 20a and 20b, and between battery cells 20b and 20c. The battery cells 20a, 20b, 20c and the heat transfer suppression component 50 are further housed in the battery casing 30.

[0363] It should be noted that the heat transfer suppression component 50 is as described above.

[0364] In the battery pack 100 configured in this way, the heat transfer suppression component has a frame, thus ensuring the spacing between battery cells. In addition, since the heat insulation material is formed thinner than the frame, damage to the battery casing and reduction in battery performance can be suppressed when battery cells 20a, 20b, and 20c deform, and the propagation of heat between battery cells in case of abnormality can be suppressed.

[0365] It should be noted that the battery pack 100 in this embodiment is not limited to... Figure 2 The illustrated battery pack. For example, the heat transfer suppression component 50 may be disposed not only between battery cells 20a and 20b, and between battery cells 20b and 20c, but also between battery cells 20a, 20b, 20c and the battery housing 30, or attached to the inner surface of the battery housing 30.

[0366] In a battery pack 100 configured in this way, the spread of flames to the outside of the battery casing 30 can be suppressed in the event of a fire in one of the battery cells. For example, the battery pack 100 of this embodiment is sometimes used in electric vehicles (EVs) and is installed under the floor of the occupants. In this case, even if a battery cell catches fire, the safety of the occupants can be ensured.

[0367] In addition, the heat transfer suppression component 50 can be located not only between each battery cell, but also between the battery cells 20a, 20b, 20c and the battery casing 30. Therefore, there is no need to manufacture new fireproof materials, and a low-cost and safe battery pack 100 can be easily constructed.

[0368] It should be noted that the heat transfer suppression component of this embodiment can be manufactured into various shapes depending on its manufacturing method. Therefore, it can be adapted to any shape regardless of the shape of the battery cells 20a, 20b, 20c and the battery casing 30. Specifically, in addition to prismatic batteries, it can also be applied to cylindrical batteries, flat batteries, etc.

[0369] Various embodiments have been described above with reference to the accompanying drawings, but the present invention is certainly not limited to these examples. It will be apparent to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and it is understood that they also fall within the technical scope of the present invention. Furthermore, the constituent elements of the above embodiments can be combined arbitrarily without departing from the spirit of the invention.

[0370] It should be noted that this application is based on Japanese patent application (Japanese Patent Application No. 2023-124841) filed on July 31, 2023, the contents of which are incorporated herein by reference.

[0371] Symbol Explanation

[0372] 1. Organic Fiber

[0373] 3. Adhesive fibers

[0374] 8.54 Void

[0375] 10, 40, 60, 70, 80, 90, 110 thermal insulation materials

[0376] 10a First thermal insulation material

[0377] 10b Second thermal insulation material

[0378] 20a, 20b, 20c battery cells

[0379] 30 Battery casing

[0380] 50, 120, 130, 140, 150, 160 Heat transfer suppression components

[0381] 51 Elastic Material

[0382] 52,112,312 membranes

[0383] 53 Frame

[0384] Frame components 53a and 53b

[0385] 58a, 58b, 58c, 58d partition walls

[0386] 100 battery pack

Claims

1. A heat transfer suppression component, characterized in that, It has the following characteristics: A frame that surrounds the outer perimeter when viewed from above; and Sheet-shaped thermal insulation material, disposed on the inner side of the frame, has a pair of main surfaces. In a cross-sectional view orthogonal to the top view, the thickness of the insulation material is thinner than the thickness of the frame.

2. The heat transfer suppression component according to claim 1, characterized in that, It has a membrane covering the main surface of the insulation material.

3. The heat transfer suppression component according to claim 2, characterized in that, At least one of the pair of main surfaces has a gap between itself and the membrane.

4. The heat transfer suppression component according to claim 1, characterized in that, It has an elastic material laminated on at least one of the pair of main surfaces of the insulation material, wherein, in the cross-section, the thickness of the laminate of the insulation material and the elastic material is approximately the same as, or thinner than, the thickness of the frame.

5. The heat transfer suppression component according to claim 4, characterized in that, The laminated body has a pair of main surfaces orthogonal to the thickness direction. The heat transfer suppression component has a film covering the one pair of outer main surfaces.

6. The heat transfer suppression component according to claim 5, characterized in that, It has a gap between at least one of the outer main surfaces and the membrane.

7. The heat transfer suppression component according to claim 4, characterized in that, The elastic material comprises at least one selected from synthetic rubber, natural rubber, and thermoplastic elastomers.

8. The heat transfer suppression component according to claim 1, characterized in that, It also has partition walls that divide the inner side of the frame into multiple regions, and multiple thermal insulation materials disposed in the multiple regions.

9. The heat transfer suppression component according to claim 8, characterized in that, The plurality of insulation materials include a first insulation material and a second insulation material having different properties from each other.

10. The heat transfer suppression component according to claim 9, characterized in that, The elastic modulus of the first thermal insulation material is less than that of the second thermal insulation material.

11. The heat transfer suppression component according to claim 10, characterized in that, The first thermal insulation material is disposed in at least the central region of the plurality of regions.

12. The heat transfer suppression component according to claim 8, characterized in that, When viewed from above, the width of the partition wall in the direction orthogonal to the length direction is smaller than the width of the frame in the direction orthogonal to the length direction.

13. The heat transfer suppression component according to any one of claims 8 to 12, characterized in that, The partition wall is mainly made of insulating material.

14. The heat transfer suppression component according to any one of claims 1 to 12, characterized in that, The frame is primarily made of insulating material.

15. The heat transfer suppression component according to any one of claims 1 to 12, characterized in that, The insulation material comprises inorganic particles and organic fibers.

16. A battery pack having a plurality of battery cells and a heat transfer suppression component according to any one of claims 1 to 12, wherein the plurality of battery cells are connected in series or in parallel.

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