Heat transfer suppression sheet, assembled battery device, self-propelled vehicle, and heat transfer suppression sheet manufacturing method

Abstract

To provide a heat transfer suppression sheet, assembled battery device, self-propelled vehicle, and heat transfer suppression sheet manufacturing method that even when an expansion amount or contraction amount of a battery is large, are capable of absorbing these deformation amounts and expanding a place in which they can be located.SOLUTION: Heat transfer suppression sheets 110 are two-folded on sides opposite to each other by a bent parts 111a, 111b, and have a cross-sectional shape formed in an N shape. In this case, the heat transfer suppression sheets 110 have a first sheet piece 112, second sheet piece 113, and third sheet piece 114 connected via the bent parts 111a, 111b that are formed in the approximately same size as those of first wall surfaces 102a, 102b of a battery cell 101. The heat transfer suppression sheets 110 are disposed one by one between mutually adjacent two battery cells 101 and between the first wall surfaces 120a, 120b of a housing 120 and the battery cell 101.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a heat-transfer-suppressing sheet that is arranged to suppress heat transfer within an assembled battery device in which multiple battery cells are arranged adjacent to one another, an assembled battery device equipped with this heat-transfer-suppressing sheet, a self-propelled vehicle equipped with this assembled battery device, and a method for manufacturing the heat-transfer-suppressing sheet. [Background technology]

[0002] Conventionally, in battery assembly devices in which multiple battery cells are arranged adjacent to one another, a heat-transfer-suppressing sheet is arranged to suppress heat transfer between adjacent battery cells. For example, Patent Document 1 below discloses a separator as a heat-transfer-suppressing sheet formed by folding inorganic fibers with low thermal conductivity into a mesh shape and forming it into a sheet. This separator is configured so that its thickness changes elastically in response to the expansion or contraction of the secondary battery cells arranged adjacent to one another. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7146744

[0004] However, in Patent Document 1, the separator is configured as a single sheet, which has a problem that the limit of the amount of expansion or contraction of the battery that can be absorbed is small, and the location where it can be placed is limited.

[0005] The present invention has been made to address the above-mentioned problems, and its object is to provide a heat-transfer-suppressing sheet, a battery assembly device, a self-propelled vehicle, and a method for manufacturing a heat-transfer-suppressing sheet that can absorb deformation even when the amount of expansion or contraction of a battery is large and can expand the area in which the battery can be placed. Summary of the Invention

[0006] To achieve the above object, the present invention is characterized by a heat-transfer-suppressing sheet that is placed to suppress heat transfer within an assembled battery device in which multiple battery cells are arranged adjacent to one another, and the heat-transfer-suppressing sheet is folded at least in two.

[0007] In this way, because the heat-transfer-suppressing sheet is folded at least in two, it can absorb the amount of deformation even if the battery cells expand or contract significantly, thereby expanding the area in which they can be placed. Furthermore, the heat-transfer-suppressing sheet according to the present invention can reduce the manufacturing burden and suppress the weight increase of the heat-transfer-suppressing sheet compared to when a thicker heat-transfer-suppressing sheet is produced.

[0008] Another feature of the present invention is that the heat-transfer-suppressing sheet is folded into three so that its cross section is N-shaped.

[0009] According to this, the heat transfer suppression sheet has a cross section that is folded in three in an N shape, and therefore has two bent portions. These two bent portions are respectively located at the upper and lower ends of the N shape, so that the heat transfer suppression sheet can exert an elastic force at least in the thickness direction of the folded heat transfer suppression sheet (in other words, in the direction that penetrates horizontally through the N shape), and can accurately follow the expansion or contraction of the battery cells.

[0010] Another feature of the present invention is that, in the heat-transfer-suppressing sheet, the two sheet pieces located at both ends in the thickness direction of the heat-transfer-suppressing sheet when folded in at least two are formed to be the same size.

[0011] According to this, the heat transfer suppressing sheet is formed so that the two sheet pieces located at both ends in the thickness direction of the folded heat transfer suppressing sheet are the same size, and therefore the manner in which each of these two sheet pieces exchanges force with the outside is the same, and the heat transfer suppressing sheet can exert elastic force while maintaining its position between the two opposing members between which it is sandwiched, allowing it to accurately follow the expansion or contraction of the battery cells.

[0012] Another feature of the present invention is that the heat-transfer-suppressing sheet is folded in an open state in which the tip ends of two adjacent sheet pieces separated by a bend do not contact each other.

[0013] According to this, the heat-transfer-inhibiting sheet is folded in an open state in which the tip ends of two adjacent sheet pieces are spaced apart and do not come into contact with each other via the bend, thereby ensuring sufficient elastic force in the direction in which the heat-transfer-inhibiting sheet closes (in other words, the direction in which it is folded), and also ensuring breathability inside the heat-transfer-inhibiting sheet, thereby improving heat dissipation and suppressing the heat transfer of the heat-transfer-inhibiting sheet itself.

[0014] Another feature of the present invention resides in that, in the heat-transfer-suppressing sheet, the heat-transfer-suppressing sheet is housed in a bag.

[0015] In this way, since the heat-transfer-suppressing sheet is contained within the bag, it is possible to suppress influences from outside the bag, and it is also possible to suppress the heat-transfer-suppressing sheet itself from affecting the outside of the bag. In addition, the extent to which the heat-transfer-suppressing sheet spreads is restricted by the bag, so it is possible to prevent it from spreading too much.

[0016] The heat-transfer-inhibiting sheet may be subjected to influences from outside the bag, such as contamination due to the adhesion, contact, or collision of solid or fluid dirt or foreign matter, as well as thermal influences such as fire. Possible influences of the heat-transfer-inhibiting sheet on the outside of the bag include, for example, the scattering of separated pieces of the heat-transfer-inhibiting sheet into the surrounding area. The bag may be made of a resin or ceramic sheet or film, and may contain the heat-transfer-inhibiting sheet in a sealed or mesh-like state.

[0017] Furthermore, the present invention can be implemented not only as an invention of a heat-transfer-suppressing sheet, but also as an invention of a battery assembly including this heat-transfer-suppressing sheet, a self-propelled vehicle including this battery assembly, and a method of manufacturing the heat-transfer-suppressing sheet.

[0018] Specifically, the battery assembly may include a plurality of adjacently arranged battery cells, and a heat-transfer-suppressing sheet according to any one of claims 1 to 5, folded at least in half and arranged between the adjacent battery cells. This allows the battery assembly to achieve the same effects as the heat-transfer-suppressing sheet.

[0019] Furthermore, it is preferable that the battery assembly device includes a plurality of battery cells arranged adjacent to one another, a housing having a cover wall covering the outer surfaces of the plurality of battery cells and containing the plurality of battery cells, and that a heat-transfer-suppressing sheet according to any one of claims 1 to 5 is placed between the outer surfaces of the battery cells and the cover wall in a state folded at least in half. This also makes it possible to expect the same effects from the battery assembly device as those of the heat-transfer-suppressing sheet.

[0020] In these cases, it is preferable that the battery assembly have multiple heat-transfer-suppressing sheets arranged in one location. This allows the battery assembly to exert a large elastic force on the multiple heat-transfer-suppressing sheets arranged in one location. In this case, the multiple heat-transfer-suppressing sheets may be arranged in series or in parallel. In this case, the "one location" refers to between two adjacent battery cells or between adjacent battery cells and a cover wall.

[0021] In these cases, in the battery assembly device, at least two heat-transfer-suppressing sheets are arranged in one location, and the at least two heat-transfer-suppressing sheets are arranged such that at least a portion of one heat-transfer-suppressing sheet extends into the inner region of the bent portion of the other heat-transfer-suppressing sheet.

[0022] According to this, the battery assembly device has two heat transfer suppression sheets hooked onto each other in one location, which prevents the sheets from shifting position or changing posture relative to each other, allowing it to accurately follow the expansion or contraction of the battery cells, and also improves the rigidity and elasticity of the overlapping parts.

[0023] Specifically, a self-propelled vehicle may include the battery assembly device described in any one of claims 6 to 9 and an electric motor that is driven by power supplied from the battery assembly device. This allows the self-propelled vehicle to achieve the same effects as the heat transfer-suppressing sheet.

[0024] In this case, the self-propelled vehicle may be self-propelled by the driving force of the electric motor, which allows the self-propelled vehicle to be stably driven because electric power is stably supplied to the electric motor that propels the self-propelled vehicle.

[0025] Specifically, the method for manufacturing a heat-transfer-suppressing sheet is a method for manufacturing a heat-transfer-suppressing sheet that is disposed to suppress heat transfer within a battery assembly in which multiple battery cells are arranged adjacent to one another, and preferably includes a sheet-substrate forming step of forming a sheet-like sheet substrate that serves as the substrate for the heat-transfer-suppressing sheet, and a folding step of folding the sheet substrate at least in two. This method can effectively manufacture a heat-transfer-suppressing sheet that is folded at least in two. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a perspective view schematically illustrating an outline of the overall configuration of a battery assembly device equipped with a heat-transfer-suppressing sheet according to the present invention. [Figure 2] 2 is a cross-sectional view that schematically illustrates an outline of the internal configuration of the battery assembly device shown in FIG. 1. FIG. [Figure 3] 2 is a perspective view that schematically illustrates the outline of the appearance of a heat-transfer-suppressing sheet that is disposed in the battery assembly device shown in FIG. 1. FIG. [Figure 4]2 is a partial cross-sectional view schematically illustrating the arrangement of battery cells and heat-transfer-suppressing sheets in the battery assembly device shown in FIG. 1. FIG. [Figure 5] 2 is a flowchart showing a manufacturing process of the heat transfer suppressing sheet according to the present invention. [Figure 6] 2 is a block diagram showing a schematic overview of the overall configuration of an autonomous vehicle equipped with the battery assembly device shown in FIG. 1. FIG. [Figure 7] 5 is a partial cross-sectional view that schematically shows how the heat-transfer-suppressing sheet is deformed when the battery cell shown in FIG. 4 expands. FIG. [Figure 8] FIG. 10 is a partial cross-sectional view schematically showing the arrangement of a heat-transfer-suppressing sheet according to a modified example of the present invention. [Figure 9] FIG. 10 is a partial cross-sectional view schematically showing the arrangement of a heat-transfer-suppressing sheet according to another modified example of the present invention. [Figure 10] FIG. 10 is a partial cross-sectional view schematically showing the arrangement of a heat-transfer-suppressing sheet according to another modified example of the present invention. [Figure 11] FIG. 10 is a partial cross-sectional view schematically showing the arrangement of a heat-transfer-suppressing sheet according to another modified example of the present invention. [Figure 12] FIG. 10 is a partial plan view schematically showing the arrangement of a heat-transfer-suppressing sheet according to another modified example of the present invention. [Figure 13] FIG. 10 is a partial cross-sectional view schematically showing the arrangement of a heat-transfer-suppressing sheet according to another modified example of the present invention. [Figure 14] FIG. 10 is a partial cross-sectional view schematically showing the arrangement of a heat-transfer-suppressing sheet according to another modified example of the present invention. [Figure 15] FIG. 10 is a partial cross-sectional view schematically showing the arrangement of a heat-transfer-suppressing sheet according to another modified example of the present invention. [Figure 16] FIG. 10 is a partial cross-sectional view schematically showing the arrangement of a heat-transfer-suppressing sheet according to another modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, one embodiment of a heat-transfer-suppressing sheet, a battery assembly, a self-propelled vehicle, and a method for manufacturing a heat-transfer-suppressing sheet according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view schematically illustrating the overall configuration of a battery assembly 100 equipped with a heat-transfer-suppressing sheet 110 according to the present invention. FIG. 2 is a cross-sectional view schematically illustrating the internal configuration of the battery assembly 100 shown in FIG. 1. Note that the schematic diagrams referred to in this specification may be exaggerated to facilitate understanding of the present invention, and therefore the dimensions and proportions of the components may differ.

[0028] This battery assembly device 100 is a power supply device that supplies power to a drive motor 203 provided in a self-propelled vehicle 200, which will be described later.

[0029] (Configuration of battery assembly device 100) The battery assembly device 100 is mainly composed of battery cells 101, a heat transfer suppressing sheet 110, and a housing 120.

[0030] The battery cell 101 is the smallest unit of battery that generates a portion of the power generated by the battery assembly device 100, and is configured as a so-called secondary battery that can be charged and discharged. In this embodiment, the battery cell 101 is configured as a lithium ion battery, but it goes without saying that it can also be configured as other secondary batteries, such as nickel-metal hydride batteries, nickel-cadmium batteries, or lead batteries. Note that the battery cell 101 can also be configured as a non-rechargeable primary battery instead of a secondary battery.

[0031] This battery cell 101 is configured by sealing opposing positive and negative electrode plates (not shown) in a sealed cell casing 102 while they are immersed in an electrolyte (not shown). In this case, the cell casing 102 is configured by forming an aluminum plate material into a box shape. More specifically, the cell casing 102 is formed into a rectangular box shape with long sides extending horizontally and short sides extending heightwise when viewed from the front, and has a pair of first wall surfaces 102a, 102b arranged opposite each other, with the distance between the first wall surfaces 102a, 102b being shorter than the short sides.

[0032] In this embodiment, the longitudinal direction of the battery cell 101 is the X-axis direction (the width direction of the battery cell 101), the up-down direction perpendicular to the X-axis direction is the Z-axis direction, and the direction perpendicular to the X-axis direction and the Z-axis direction (the thickness direction of the battery cell 101) is the Y-axis direction.

[0033] Positive and negative electrode terminals 103 for electrically connecting the battery cell 101 to an external device are provided in a protruding state on the top surface of the cell casing 102. A gas release valve (not shown) is also provided on the top surface of the cell casing 102 between the positive and negative electrode terminals 103.

[0034] As shown in Figures 3 and 4, the heat-transfer-suppressing sheet 110 is a component that suppresses the propagation of heat generated by the battery cell 101 to the surrounding area, and is made by molding a material with low thermal conductivity into a sheet. More specifically, the heat-transfer-suppressing sheet 110 is formed into a sheet that is flexible enough to be bent, yet rigid enough to be self-supporting. The heat-transfer-suppressing sheet 110 is made by molding a mixture of inorganic fibers that exhibit heat insulation properties and inorganic particles (powder) that exhibit dehydration properties into a sheet.

[0035] In this case, the inorganic fibers may be composed of one or more of alumina fibers, silica-alumina fibers, silica fibers, glass fibers, rock wool, potassium titanate fibers, ceramic fibers, kaolin fibers, bauxite fibers, kyanoid fibers, boron fibers, magnesia fibers, metal fibers, etc. Furthermore, the inorganic particles (powders) may be composed of one or more of aluminum hydroxide, magnesium hydroxide, silica, titania, aluminum oxide, zirconium oxide, mullite, cordierite, silicon carbide, silicon nitride, etc.

[0036] This heat-transfer-suppressing sheet 110 is folded in three so that its cross section has an N-shape. More specifically, heat-transfer-suppressing sheet 110 is folded at two positions that divide heat-transfer-suppressing sheet 110 (a sheet base material described below), which extends in a rectangular (strip) shape before folding, into thirds in the longitudinal direction, to form bent portions 111a and 111b. In this case, heat-transfer-suppressing sheet 110 is folded in opposite directions, with bent portion 111a being a mountain fold and bent portion 111b being a valley fold, to form an N-shape in cross section.

[0037] Furthermore, in this case, the bent portions 111a and 111b of the heat-transfer-restricting sheet 110 are formed at two positions that divide the heat-transfer-restricting sheet 110 (sheet base material) into thirds in the longitudinal direction before folding. Therefore, the first sheet piece 112 and the second sheet piece 113 connected to both sides of the bent portion 111a are the same size, and the second sheet piece 113 and the third sheet piece 114 connected to both sides of the bent portion 111b are the same size. Therefore, the first sheet piece 112 and the third sheet piece 114 are the same size. In this case, the first sheet piece 112, the second sheet piece 113, and the third sheet piece 114 are formed to be approximately the same size (strictly speaking, slightly smaller) as the first wall surfaces 102a and 102b of the battery cells 101 that the heat-transfer-restricting sheet 110 faces.

[0038] Furthermore, bent portions 111a and 111b are folded with such strength that the leading end side of first sheet piece 112 and the leading end side of second sheet piece 113 are spaced apart from each other, and that the leading end side of second sheet piece 113 and the leading end side of third sheet piece 114 are spaced apart from each other. As a result, in heat-transfer-suppressing sheet 110, the springback (restoring force of the folded portion) of bent portions 111a and 111b causes the leading end side of first sheet piece 112 and the leading end side of second sheet piece 113 to not come into complete contact with each other, resulting in an open state where the leading ends elastically separate from each other, and the leading end side of second sheet piece 113 and the leading end side of third sheet piece 114 to not come into complete contact with each other, resulting in an open state where the leading ends elastically separate from each other. In this embodiment, heat-transfer-suppressing sheet 110 is formed to a thickness of 0.5 mm.

[0039] The housing 120 is a container for accommodating a plurality of battery cells 101 and a plurality of heat-transfer-suppressing sheets 110 in an alternating arrangement to form a single power supply device. In this embodiment, the housing 120 is configured by forming an aluminum plate into a rectangular box shape in a plan view that is open at the top. That is, the housing 120 is configured to include two first side walls 120a, 120b that face each other in the longitudinal direction (the Y-axis direction in the figure), second side walls 120c, 120d that face each other in the lateral direction (the X-axis direction in the figure) that is perpendicular to the longitudinal direction, a bottom plate 120e that forms the bottom of the housing 120, and an opening 121 formed on the side opposite the bottom plate 120e.

[0040] In these cases, the longitudinal length of the casing 120 is set to a length that allows the multiple battery cells 101 and the multiple heat-transfer-restricting sheets 110 to be arranged alternately and that allows for elastic expansion and contraction of the heat-transfer-restricting sheets 110. The lateral (widthwise) length of the casing 120 is set to a length that can accommodate the battery cells 101 and the heat-transfer-restricting sheets 110 in their widthwise directions. The depth (height) of the casing 120 (in the Z-axis direction in the figure) is set to a depth (height) that is higher than the main bodies of the battery cells 101 and lower than the tips of the electrode terminals 103.

[0041] In this embodiment, six battery cells 101 and seven heat-transfer-restricting sheets 110 are housed in an alternating arrangement within the housing 120. Specifically, the six battery cells 101 are arranged in the longitudinal direction within the housing 120 in an upright position, lined up in the thickness direction at predetermined intervals, and a heat-transfer-restricting sheet 110 is arranged on both sides of each battery cell 101.

[0042] That is, the heat-transfer-suppressing sheets 110 are disposed not only between two adjacent battery cells 101, but also between two first side walls 120a, 120b in the direction in which the battery cells 101 are arranged in the casing 120 (the Y-axis direction in the figure) and each battery cell 101 disposed opposite these two first side walls 120a, 120b. In this case, each heat-transfer-suppressing sheet 110 is provided in each gap while being stretchable in the thickness direction (the Y-axis direction in the figure). Note that the multiple battery cells 101 (six in this embodiment) housed in the casing 120 may be connected to each other in series or in parallel.

[0043] (Method of manufacturing heat transfer suppressing sheet 110) Next, a method for manufacturing the heat-transfer-suppressing sheet 110 will be described with reference to Fig. 5. First, as the first step, an operator performs a sheet base material forming step to manufacture the sheet base material of the heat-transfer-suppressing sheet 110. Here, the sheet base material is a sheet-like member before the heat-transfer-suppressing sheet 110 is folded, and is manufactured by a papermaking process.

[0044] The papermaking process is a conventionally known method for filtering out fibers dispersed in a liquid to form a long sheet-like paper body (not shown). Specifically, the papermaking process involves filtering out the raw materials for the heat-transfer-suppressing sheet 110, i.e., inorganic fibers and inorganic particles (powder), from a slurry-like raw material liquid obtained by adding and stirring the raw materials into water, filtering the raw materials into a long sheet, and then drying the resulting long sheet-like paper body. In this case, the long paper body is dried to a moisture content of 10% or less. In this embodiment, the long paper body is formed to a thickness of 0.5 mm. This long paper body corresponds to the sheet substrate.

[0045] The blending ratio of the inorganic fibers and inorganic powder is appropriately set according to the specifications of the heat-transfer-suppressing sheet 110 to be manufactured. In this case, the inorganic fibers are blended at a blending ratio of 5% by weight or more and 50% by weight or less of the inorganic powder. Furthermore, organic fibers can be used as the raw material for this sheet substrate, either instead of or in addition to the inorganic fibers. Organic fibers can be composed of one or more of the following: wood pulp, synthetic pulp, polyester fibers, polyamide fibers, polyimide fibers, polyvinyl alcohol-modified fibers, polyvinyl chloride fibers, polypropylene fibers, polybenzimidazole fibers, acrylic fibers, carbon fibers, phenolic fibers, nylon fibers, and cellulose fibers. Furthermore, a binder made of an organic or inorganic binder can be used as the raw material for the sheet substrate.

[0046] Next, as the second step, the worker performs a folding step in which the sheet substrate is folded in half. Specifically, the worker cuts out a strip of the sheet substrate (not shown) from the long, elongated paper body to the length required for the heat-transfer-suppressing sheet 110, and then folds this sheet substrate at each of the bends 111a and 111b. In this case, the length required for the heat-transfer-suppressing sheet 110 is the sum of the lengths of the first sheet piece 112, the second sheet piece 113, and the third sheet piece 114 that make up the heat-transfer-suppressing sheet 110. The worker may fold the strip of the sheet substrate at each of the bends 111a and 111b by hand or using a tool or machine. In these cases, the worker can smoothly fold the sheet substrate by using a blade such as a cutter to form incisions on the surface of the sheet substrate at the positions where the bends 111a and 111b will be formed.

[0047] In this case, the worker folds the sheet substrate at bend 111a in a mountain fold and at bend 111b in a valley fold. The worker also folds the sheet substrate at bends 111a and 111b to such an extent that springback (the restoring force of the folded portion) is not lost. This results in heat-transfer-suppressing sheet 110 having an N-shaped cross section.

[0048] The heat-transfer-restricting sheets 110 manufactured in this manner are placed between the battery cells 101 and between the battery cells 101 and the first side walls 120a, 120b within the housing 120. Specifically, the worker can alternately arrange the battery cells 101 and the heat-transfer-restricting sheets 110 within the housing 120 by alternately inserting the heat-transfer-restricting sheets 110 and the battery cells 101 into the housing 120 along the longitudinal direction of the housing 120. Furthermore, the worker can alternately arrange the battery cells 101 and the heat-transfer-restricting sheets 110 within the housing 120 by placing an assembly in which the heat-transfer-restricting sheets 110 and the battery cells 101 are alternately arranged within the housing 120.

[0049] 4, the worker places the heat-transfer-restricting sheet 110 inside the housing 120 with the bent portions 111a and 111b of the heat-transfer-restricting sheet 110 facing the bottom plate 120e of the cell housing 102 and the opening 121 facing the bottom plate 120e. In addition, in these cases, the worker securely attaches the battery cell 101 to the second side walls 120c and 120d or the bottom plate 120e inside the housing 120, while placing the heat-transfer-restricting sheet 110 in an unsecured state relative to the housing 120 or the battery cell 101.

[0050] Alternatively, the worker may attach the heat-transfer-restricting sheet 110 to the battery cell 101 or the first side walls 120a, 120b that the heat-transfer-restricting sheet 110 faces inside the housing 120 using adhesive or double-sided tape.

[0051] (Operation of battery assembly device 100) Next, the operation of the battery assembly device 100 configured as described above will be described. In this embodiment, the battery assembly device 100 will be described as being used as a power supply device for a self-propelled vehicle 200. Here, a brief description of the self-propelled vehicle 200 will be given.

[0052] As shown in FIG. 6, the self-propelled vehicle 200 is a vehicle that can carry people or luggage and travels under its own power, and is mainly composed of a vehicle body 201, wheels 202, a drive motor 203, an inverter 204, a control device 205, and an assembly battery device 100.

[0053] The vehicle body 201 is composed of a chassis and a body, which form the framework that supports the body of the self-propelled vehicle 200, and supports a drive motor 203, an inverter 204, and a control device 205. Naturally, the vehicle body 201 also supports various facilities that are generally provided in known automobiles, such as a steering facility for the self-propelled vehicle 200, a passenger compartment, and a luggage storage facility.

[0054] The wheels 202 are components that support the vehicle body 201 on the road surface on which the self-propelled vehicle 200 travels and that move the vehicle body 201 by rolling on this road surface, and are configured by rubber tires attached to the outside of metal wheels. A pair of wheels 202 are provided on the left and right sides of the front and rear of the vehicle body 201. In this case, the pair of left and right wheels 202 that make up the front wheels are connected to a handlebar operated by the driver via a steering mechanism (not shown). In addition, each of the four wheels 202 is provided with a brake device (not shown) that can be braked by the driver's operation.

[0055] The drive motor 203 is a prime mover that rotates and drives each of the pair of left and right wheels 202 that make up the front wheels, and is also a power generating device that generates electricity using the back torque of the self-propelled vehicle 200, and its operation is controlled by the control device 205. In this embodiment, the drive motor 203 is configured as an interior permanent magnet motor, but it can also be configured as another motor, for example, an induction motor, a surface permanent magnet synchronous motor, a synchronous reluctance motor, a switched reluctance motor, or a DC motor.

[0056] In this embodiment, the drive motor 203 is configured to rotate the wheels 202 that constitute the front wheels, but it may be configured to rotate the wheels 202 that constitute the rear wheels instead of or in addition to the front wheels. The drive motor 203 may also be configured as a so-called in-wheel motor provided inside each wheel 202. In addition, in Fig. 6, the left side of the figure is the front side of the self-propelled vehicle 200, and the right side is the rear side.

[0057] The inverter 204 converts the direct current from the battery assembly device 100 into alternating current of an appropriate frequency depending on the degree of depression of the accelerator pedal (not shown) of the self-propelled vehicle 200, and supplies the converted alternating current to the drive motor 203. The inverter 204 is also an electrical circuit that converts the alternating current generated by the drive motor 203 when the self-propelled vehicle 200 decelerates into direct current and returns it to the battery assembly device 100 for charging.

[0058] The control device 205 is configured by a microcomputer including a CPU, ROM, RAM, etc., and controls the operation of the drive motor 203 as well as the overall operation of the self-propelled vehicle 200. The control device 205 also constantly monitors the operating status of the battery assembly device 100, such as charging and discharging.

[0059] The battery assembly device 100 supplies power to the drive motor 203 and various electrical and electronic equipment that requires power in the self-propelled vehicle 200. One or more battery assembly devices 100 are provided in the vehicle body 201 depending on the amount of power required by the self-propelled vehicle 200.

[0060] In the battery assembly device 100, the cell casing 102 expands or contracts as the battery cells 101 generate heat due to charging or discharging. In this case, as shown by the two-dot chain line in Figure 7, when the cell casing 102 expands, the first wall surfaces 102a and 102b of the cell casing 102 press against the first sheet piece 112 and / or the third sheet piece 114 of the heat-transfer-suppressing sheet 110, causing the bending angles of the bent portions 111a and 111b to elastically decrease against their own elastic force. As a result, the distance between the first sheet piece 112 and the third sheet piece 114 of the heat-transfer-suppressing sheet 110 decreases, i.e., the length of the heat-transfer-suppressing sheet 110 in the thickness direction (the Y-axis direction in the figure) decreases, and the heat-transfer-suppressing sheet 110 deforms to follow the deformation of the cell casing 102.

[0061] On the other hand, when the cell casing 102 contracts, the first wall surfaces 102a, 102b of the cell casing 102 deform in a direction away from the first sheet piece 112 and / or the third sheet piece 114, and the bending angle of the bent portions 111a, 111b of the heat-transfer-restricting sheet 110 elastically increases due to its own elastic force. As a result, the distance between the first sheet piece 112 and the third sheet piece 114 of the heat-transfer-restricting sheet 110 increases, i.e., the length of the heat-transfer-restricting sheet 110 in the thickness direction (the Y-axis direction in the figure) increases, and the heat-transfer-restricting sheet 110 deforms to follow the deformation of the cell casing 102 (see FIG. 4).

[0062] In other words, the battery assembly 100 can maintain the heat-transfer-restricting sheet 110 in contact with the cell casing 102 even when the cell casing 102 expands or contracts, thereby preventing heat from being transferred from the first wall surfaces 102a, 102b of the cell casing 102 to the surrounding area. In particular, when the heat-transfer-restricting sheet 110 is elongated and deformed, the first sheet piece 112, second sheet piece 113, and third sheet piece 114 are spaced apart from one another, thereby further reducing the heat transfer of the heat-transfer-restricting sheet 110. Furthermore, if a battery cell 101 catches fire, the heat-transfer-restricting sheet 110 can prevent the progression of damage caused by the flames due to the first sheet piece 112, second sheet piece 113, and third sheet piece 114 that are independent from one another.

[0063] As can be seen from the above description of operation, according to the above embodiment, heat-transfer-suppressing sheet 110 is folded in two at bent portions 111a and 111b, so that even if the battery cells 101 expand or contract significantly, this deformation can be absorbed and the placement area can be expanded. Furthermore, heat-transfer-suppressing sheet 110 according to the present invention can reduce the manufacturing burden and suppress the weight increase of heat-transfer-suppressing sheet 110 compared to manufacturing a thicker heat-transfer-suppressing sheet.

[0064] Furthermore, the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the scope of the present invention. In the description of each modification, the same parts as those in the above-described embodiments are designated by the same reference numerals, and redundant description will be omitted.

[0065] For example, in the above embodiment, the heat-transfer-inhibiting sheet 110 is folded in three to form an N-shaped cross section. However, the heat-transfer-inhibiting sheet 110 only needs to be folded in two at at least one location. Therefore, the heat-transfer-inhibiting sheet 110 can be formed, for example, by folding a single sheet substrate in two at a single bent portion 111a, as shown in FIG. 8 . Alternatively, the heat-transfer-inhibiting sheet 110 can be formed, as shown in FIG. 9 , by folding a single sheet substrate in two at four bent portions 111a, 111b, 111c, and 111d, so that the entire sheet is folded in four. In this case, the heat-transfer-inhibiting sheet 110 is integrally formed with five sheet pieces: a first sheet piece 112, a second sheet piece 113, a third sheet piece 114, a fourth sheet piece 115, and a fifth sheet piece 116. Alternatively, the heat-transfer-inhibiting sheet 110 can be formed, for example, with an M-shaped or W-shaped cross section.

[0066] In the above embodiment, the heat-transfer-suppressing sheet 110 is configured with the bent portions 111a and 111b bent at acute angles. However, the heat-transfer-suppressing sheet 110 can also be configured with the bent portions 111a and 111b bent into a curved shape, as shown in FIG.

[0067] Furthermore, in the above embodiment, the battery assembly 100 has one heat-transfer-restricting sheet 110 disposed between each pair of adjacent battery cells 101 and between each battery cell 101 and the first side walls 120a, 120b of the casing 120. However, the battery assembly 100 may also have two or more heat-transfer-restricting sheets 110 disposed between each pair of adjacent battery cells 101 and / or between each battery cell 101 and the first side walls 120a, 120b of the casing 120.

[0068] For example, two heat-transfer-suppressing sheets 110a, 110b can be arranged in series between two adjacent battery cells 101, as shown in Fig. 11. Alternatively, for example, two heat-transfer-suppressing sheets 110a, 110b can be arranged in parallel between two adjacent battery cells 101, as shown in Fig. 12.

[0069] Furthermore, for example, when two heat-transfer-reducing sheets 110a, 110b are folded in half, the first sheet piece 112 of one heat-transfer-reducing sheet 110a can be positioned between two adjacent first and second sheet pieces 112, 113 via the bent portion 111a in the other heat-transfer-reducing sheet 110b, as shown in FIG. 13.

[0070] Furthermore, for example, when two heat-transfer-restricting sheets 110a, 110b are folded in half, one heat-transfer-restricting sheet 110b can be placed entirely in the same orientation as heat-transfer-restricting sheet 110a in the area inside bent portion 111a of heat-transfer-restricting sheet 110a, as shown in Fig. 14. Furthermore, for example, when two heat-transfer-restricting sheets 110a, 110b are folded in half, one heat-transfer-restricting sheet 110b can be placed entirely in the area inside bent portion 111a of heat-transfer-restricting sheet 110a, as shown in Fig. 15.

[0071] That is, at least two heat-transfer-suppressing sheets 110a, 110b can be arranged such that a portion of one heat-transfer-suppressing sheet 110b is sandwiched between two adjacent sheet pieces, the first sheet piece 112 and the second sheet piece 113, via the bent portion 111a of the other heat-transfer-suppressing sheet 110a. In this manner, the battery assembly 100 has the two heat-transfer-suppressing sheets 110a, 110b hooked to each other in one location. This prevents the sheets from shifting position or changing orientation, allowing them to accurately follow the expansion and contraction of the battery cells 101 and improves the rigidity and elasticity of the overlapping portions. Furthermore, when two or more heat-transfer-suppressing sheets 110 are arranged in the battery assembly 100, the heat-transfer-suppressing sheets 110 may be the same size or shape or may have different sizes or shapes.

[0072] In the above embodiment, the heat-transfer-suppressing sheet 110 is disposed in an exposed state between two adjacent battery cells 101 and between the battery cell 101 and the first side walls 120a, 120b of the housing 120. However, as shown in Fig. 16, the heat-transfer-suppressing sheet 110 can also be disposed between two adjacent battery cells 101 and / or between the battery cell 101 and the first side walls 120a, 120b of the housing 120 while housed in a pouch 130.

[0073] In this case, bag 130 is made of a flexible and / or stretchable resin or ceramic sheet (including those that are mesh-like or have ventilation holes) or film (including those that are mesh-like or have ventilation holes), and contains heat-transfer-inhibiting sheet 110 in a sealed or unsealed state. In this way, heat-transfer-inhibiting sheet 110 is contained within bag 130, which can reduce influences from outside bag 130 and can also reduce the heat-transfer-inhibiting sheet 110 itself from affecting the outside of bag 130. Furthermore, the extent to which heat-transfer-inhibiting sheet 110 spreads is restricted by bag 130, which can prevent it from spreading too much.

[0074] In this case, influences that the heat-transfer-suppressing sheet 110 receives from outside the bag 130 include, for example, adhesion of solid or fluid dirt or foreign matter, staining due to contact or collision, and thermal influences such as fire. Also, possible influences that the heat-transfer-suppressing sheet 110 may have on the outside of the bag 130 include, for example, the scattering of separated material from the heat-transfer-suppressing sheet 110 into the surrounding area.

[0075] In the above embodiment, the first sheet piece 112, the second sheet piece 113, and the third sheet piece 114 of the heat-transfer-suppressing sheet 110 are formed to be the same size as one another. In this case, the first sheet piece 112, the second sheet piece 113, and the third sheet piece 114 are formed to be approximately the same size as the first wall surfaces 102a and 102b of the battery cell 101. However, the heat-transfer-suppressing sheet 110 can also be formed so that the first sheet piece 112, the second sheet piece 113, and the third sheet piece 114 are different sizes from one another. Furthermore, the first sheet piece 112, the second sheet piece 113, and the third sheet piece 114 can be formed to be the same size as the first wall surfaces 102a and 102b of the battery cell 101, or they can be smaller or larger than the first wall surfaces 102a and 102b.

[0076] In the above embodiment, the heat-transfer-suppressing sheet 110 is formed to have a thickness of 0.5 mm. However, the thickness of the heat-transfer-suppressing sheet 110 is determined appropriately depending on the specifications of the heat-transfer-suppressing sheet 110 or the battery assembly device 100. Therefore, the heat-transfer-suppressing sheet 110 may be formed to have a thickness of 0.5 mm or less or 0.5 mm or more. In this case, forming the heat-transfer-suppressing sheet 110 to have a thickness of 1.5 mm or less, preferably 1 mm or less, makes it easier to fold.

[0077] In the above embodiment, the heat-transfer-suppressing sheet 110 is arranged in an open state between two adjacent battery cells 101 and between the battery cell 101 and the first side walls 120a, 120b of the casing 120, with the leading end of the first sheet piece 112 and the leading end of the second sheet piece 113 spaced apart and with the leading end of the second sheet piece 113 and the leading end of the third sheet piece 114 spaced apart. However, the heat-transfer-suppressing sheet 110 can also be arranged in a closed state between two adjacent battery cells 101 and / or between the battery cell 101 and the first side walls 120a, 120b of the casing 120, with the leading end of the first sheet piece 112 and the leading end of the second sheet piece 113 in contact with each other and the leading end of the second sheet piece 113 and the leading end of the third sheet piece 114 in contact with each other. In this case, heat-transfer-suppressing sheet 110 follows the expansion or contraction of battery cell 101 by slight deformation of bent portions 111a, 111b or elastic deformation of the thickness of first sheet piece 112, second sheet piece 113, and third sheet piece 114.

[0078] In the above embodiment, the heat-transfer-suppressing sheet 110 is arranged between two adjacent battery cells 101 and between the battery cell 101 and the first side walls 120a, 120b of the housing 120 with the bent portions 111a, 111b facing the bottom plate 120e and the opening 121 of the housing 120, respectively. However, as shown in Fig. 12, the heat-transfer-suppressing sheet 110 can also be arranged between two adjacent battery cells 101 and / or between the battery cell 101 and the first side walls 120a, 120b of the housing 120 with the bent portions 111a, 111b facing the second side walls 120c, 120d of the housing 120, respectively.

[0079] Furthermore, in the above embodiment, the battery assembly device 100 is configured to supply power to the drive motor 203 of the self-propelled vehicle 200 and various electrical and electronic equipment that requires power in the self-propelled vehicle 200. However, the battery assembly device 100 can also be configured to supply power to one of the drive motor 203 of the self-propelled vehicle 200 and various electrical and electronic equipment that requires power in the self-propelled vehicle 200.

[0080] In the above embodiment, the housing 120 is formed in a box shape that is open at the top. However, the housing 120 only needs to be configured to hold the battery cells 101 and the heat-transfer-suppressing sheet 110. Therefore, the housing 120 can be configured, for example, without at least one of the second side walls 120c, 120d and the bottom plate 120e. Furthermore, the battery assembly device 100 can be configured without the housing 120 if, for example, the battery cells 101 are physically connected directly to each other or fixed to a plate-like body such as the bottom plate 120e to prevent misalignment.

[0081] In the above embodiment, the battery assembly 100 is used as a power supply device for a self-propelled vehicle 200 such as an electric car. However, the battery assembly 100 can also be used as a power supply device for self-propelled vehicles 200 other than electric cars, for example, hybrid cars. The battery assembly 100 can also be used as a power supply device for machinery, buildings such as homes or facilities, or vehicles that require a power supply device other than the self-propelled vehicle 200. [Explanation of symbols]

[0082] 100...Collective battery device, 101... battery cell, 102... cell housing, 102a, 102b... first wall surface, 103... electrode terminal, 110, 110a, 110b...heat transfer suppression sheets, 111a, 111b, 111c, 111d...bending portions, 112...first sheet piece, 113...second sheet piece, 114...third sheet piece, 115...fourth sheet piece, 116...fifth sheet piece, 120... housing, 120a, 120b... first side wall, 120c, 120d... second side wall, 120e... bottom plate, 121... opening, 130...Bag body, 200...self-propelled vehicle, 201...vehicle body, 202...wheel, 203...drive motor, 204...inverter, 205...control device.

Claims

1. A heat-transfer suppressing sheet that is arranged to suppress heat transfer in an assembled battery device in which a plurality of battery cells are arranged adjacent to one another, The heat-transfer-suppressing sheet is characterized in that it is folded at least in two.

2. The heat transfer suppressing sheet according to claim 1, The heat-transfer-suppressing sheet is characterized in that the cross section is folded in three into an N-shape.

3. The heat transfer suppressing sheet according to claim 1, The heat-transfer-suppressing sheet is characterized in that the two sheet pieces located at both ends in the thickness direction of the at least two-folded heat-transfer-suppressing sheet are formed to be the same size.

4. The heat transfer suppressing sheet according to claim 1, The heat-transfer-suppressing sheet is characterized in that the two adjacent sheet pieces are folded in an open state with their leading ends spaced apart and not in contact with each other via a bent portion.

5. The heat transfer suppressing sheet according to claim 1, The heat-transfer-suppressing sheet is contained in a bag.

6. A plurality of battery cells arranged adjacent to each other; 6. A battery assembly device, wherein the heat transfer suppressing sheet according to claim 1 is disposed between the adjacent battery cells in the at least two-folded state.

7. A plurality of battery cells arranged adjacent to each other; a housing having a cover wall that covers outer surfaces of the plurality of battery cells and that houses the plurality of battery cells; 6. A battery assembly device, wherein the heat transfer suppressing sheet according to claim 1 is disposed between the outer surface of the battery cell and the cover wall in the at least two-folded state.

8. The battery assembly device according to claim 6 or 7, The heat transfer suppressing sheet is A battery assembly device characterized by having multiple batteries arranged in one place.

9. The battery assembly device according to claim 8, The heat transfer suppressing sheet is At least two of the heat transfer suppression sheets are arranged in the one location, The at least two heat transfer suppressing sheets are 1. A battery assembly device, comprising: one heat-transfer-suppressing sheet disposed so that at least a portion of the other heat-transfer-suppressing sheet is inserted into an inner region of a bent portion of the other heat-transfer-suppressing sheet.

10. a battery assembly device according to any one of claims 6 to 9; a self-propelled vehicle comprising an electric motor that is driven by power supplied from the battery assembly device.

11. The self-propelled vehicle according to claim 10, The self-propelled vehicle is self-propelled by the driving force of the electric motor.

12. A method for manufacturing a heat-transfer-suppressing sheet that is arranged to suppress heat transfer in an assembled battery device in which a plurality of battery cells are arranged adjacent to one another, comprising: a sheet base material forming step of forming a sheet base material that serves as a base material for the heat transfer-suppressing sheet; and folding the sheet substrate at least twice.

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