Containment vessel for a module battery and module battery

Abstract

The present invention provides a module battery which is easily produced, while having excellent heat retention performance during a standby time. The present invention provides a container for module batteries, the container comprising: a box body in which a plurality of unit batteries, each of which is a high-temperature operation secondary battery, are contained; and a cover body which closes an opening part of the box body. With respect to this container for module batteries, the box body and the cover body have an atmospheric thermal insulation structure that is provided with a cuboidal inner container and a cuboidal outer container, each of which is formed of a metal plate, and a thermal insulation material that is filled into the space between the inner container and the outer container. With respect to each of the box body and the cover body, the inner container and the outer container are not in contact with each other, and the thermal insulation material is exposed only at the opening edge.

Description

Technical Field

[0001] The present invention relates to a module battery formed by connecting a plurality of high-temperature operating secondary batteries, and particularly to a structure for heat dissipation thereof.

Background Art

[0002] As a storage battery used by connecting to a power system, a sodium-sulfur battery (hereinafter referred to as a NaS battery) is already known. A single NaS battery (single cell) generally has a structure in which the active materials, metallic sodium (Na) and sulfur (S), are isolated and housed in a cell (battery container) with beta-alumina, a solid electrolyte having Na ion conductivity, as a separator, and is a high-temperature operating secondary battery. The operating temperature is about 300°C. In a single cell, an electromotive force is generated by the electrochemical reaction of both active materials in a molten (liquid) state at such an operating temperature.

[0003] NaS batteries are usually used in the form of a module battery in which a plurality of single cells (battery assembly) are connected to each other and housed in a heat-insulating container in order to ensure a desired capacity and output (see, for example, Patent Document 1). In a module battery, a plurality of circuits (strings) in which a plurality of single cells are connected in series are connected in parallel to form a block, and a plurality of such blocks are connected in series.

[0004] In order for a module battery of a NaS battery (hereinafter simply referred to as a module battery) to operate stably, in addition to maintaining a suitable operating temperature of about 300°C during operation (when charging and discharging are performed in a single cell), it is also required to maintain the operating temperature in order to keep the active material in a molten (liquid) state even during standby when charging and discharging are not performed in the single cell.

[0005] During operation, the reaction heat of the active material is usually used to maintain the operating temperature. However, during standby when the reaction of the active material does not occur, such reaction heat cannot be utilized. Therefore, in a conventional module battery, a heater is provided inside the housing container, and during standby, the inside of the housing container is heated by the heater, and a heat insulation structure is adopted for the housing container itself to suppress heat dissipation to the outside, thereby maintaining the operating temperature.

[0006] For example, Patent Document 1 discloses a module battery in which a housing container is composed of a box body and a lid having a vacuum heat insulation structure, and heaters are arranged on the side and bottom inside the box body. The vacuum heat insulation structure of the box body and the lid is realized by forming the outer surface with a metal (stainless steel) plate and filling a vacuum heat insulation board inside.

[0007] However, forming the box body and the lid having a vacuum heat insulation structure as disclosed in Patent Document 1 and further maintaining the vacuum state over time is not necessarily easy. For example, when forming the box body and the lid, it is required to securely weld the plates together without gaps by welding. When the module battery is in use, if the vacuum is broken or a vacuum defect occurs for some reason, there is also a problem that heat insulation cannot be ensured.

[0008] Also, from the viewpoint of ensuring productivity (mass productivity), it is also desirable not to unnecessarily complicate the manufacturing process.

Prior Art Documents

Patent Documents

[0009]

Patent Document 1

Summary of the Invention

[0010] The present invention has been made in view of the above problems, and an object thereof is to provide a module battery that is superior in heat retention performance during standby and is easier to manufacture than conventional ones.

[0011] In order to solve the above problems, a first aspect of the present invention is a container for housing a module battery, comprising: a box body in which a plurality of single cells, each being a high-temperature operating secondary battery, are housed; and a lid body for closing an opening portion of the box body, wherein the box body and the lid body each have a hermetic heat insulation structure including a rectangular parallelepiped inner container and an outer container both made of a metal plate, and a heat insulating material filled between the inner container and the outer container, and in each of the box body and the lid body, the inner container and the outer container do not contact each other, and the heat insulating material is exposed only at the opening end portion.

[0012] Further, a second aspect of the present invention is a container for housing a module battery according to the first aspect, wherein at each of the opening end portions of the box body and the lid body, a first bent portion bent from a side plate of the inner container and a second bent portion bent from a side plate of the outer container form a gap, and the heat insulating material is exposed from the gap.

[0013] Further, a third aspect of the present invention is a container for housing a module battery according to the second aspect, wherein the thickness of the heat insulating material is 10 mm or more and 50 mm or less, the gap is 8 mm or more, and the widths of the first bent portion and the second bent portion are 1 mm or more.

[0014] Further, a fourth aspect of the present invention is a container for housing a module battery according to any one of the first to third aspects, wherein in each of the outer container and the inner container of the box body and the lid body, at each of the four corners, a protruding portion is provided in which one overhanging portion and the other bent portion of the side plates orthogonal to each other are integrated.

[0015] Further, a fifth aspect of the present invention is a container for housing a module battery according to the fourth aspect, wherein at the protruding portion, the side plates orthogonal to each other are fixed with rivets.

[0016] Further, a sixth aspect of the present invention is a housing container for a module battery according to the second or third aspect, wherein the heat insulating material is formed by laminating a plurality of heat insulating material plates, and the gap is smaller than the thickness of the heat insulating material plate.

[0017] Further, a seventh aspect of the present invention is a housing container for a module battery according to any one of the first to sixth aspects, wherein the thermal conductivity of the heat insulating material is 20 mW / m·K or less.

[0018] Further, an eighth aspect of the present invention is a module battery including a plurality of single cells each being a high-temperature operation type secondary battery, a box body in which the plurality of single cells are housed, and a lid body for closing an opening portion of the box body, wherein the box body and the lid body each have a hermetic heat insulation structure including a rectangular parallelepiped inner container and an outer container both made of a metal plate, and a heat insulating material loaded between the inner container and the outer container, and in each of the box body and the lid body, the inner container and the outer container do not contact each other, and the heat insulating material is exposed only at the opening end portion.

[0019] Further, a ninth aspect of the present invention is the module battery according to the eighth aspect, wherein at each of the opening end portions of the box body and the lid body, a first bent portion bent from a side plate of the inner container and a second bent portion bent from a side plate of the outer container form a gap, and the heat insulating material is exposed from the gap.

[0020] Further, a tenth aspect of the present invention is the module battery according to the ninth aspect, wherein the thickness of the heat insulating material is 10 mm or more and 50 mm or less, the gap is 8 mm or more, and the widths of the first bent portion and the second bent portion are 1 mm or more.

[0021] Moreover, an eleventh aspect of the present invention is the modular battery according to any one of the eighth to tenth aspects, wherein each of the outer container and the inner container of the box body and the lid body is provided with a protruding portion at each of the four corners, in which an overhanging portion of one side plate and a bent portion of the other side plate that are orthogonal to each other are integrated.

[0022] Furthermore, a twelfth aspect of the present invention is the modular battery according to the eleventh aspect, wherein, in the protruding portion, the side plates orthogonal to each other are fixed with rivets.

[0023] Moreover, a thirteenth aspect of the present invention is the modular battery according to the ninth or tenth aspect, wherein the heat insulating material is formed by laminating a plurality of heat insulating material plates, and the gap is smaller than the thickness of the heat insulating material plates.

[0024] Furthermore, a fourteenth aspect of the present invention is the modular battery according to any one of the eighth to thirteenth aspects, wherein the heat conductivity of the heat insulating material is 20 mW / m·K or less.

[0025] According to the first to fourteenth aspects of the present invention, by making the storage container of the modular battery have an air heat insulation structure in which the inner container and the outer container do not contact each other, heat transfer from the inner container to the outer container is blocked. Therefore, compared with the case of adopting a vacuum heat insulation structure, heat radiation from the outer container surface to the outside during standby of the modular battery is reduced. Furthermore, the problem of poor heat insulation during use, which is a concern when adopting a vacuum heat insulation structure, will not occur. In addition, by exposing the heat insulating material at the opening ends of the box body and the lid body, deformation of the box body and the lid body due to heating and expansion of air during use of the modular battery is suppressed.

[0026] In particular, according to the second, third, sixth, ninth, tenth, and thirteenth aspects, while ensuring the strength of the box body and the lid body against deformation caused by external forces, when the temperature rises (especially during the first temperature rise), gas generated from the binder of the heat insulating material or the like stays inside the box body or the lid body, and the box body and the lid body are also prevented from deforming as the air existing inside the box body and the lid body expands due to heating during the use of the module battery.

[0027] In particular, according to the fourth, fifth, eleventh, and twelfth aspects, the strength of the box body and the lid body against deformation caused by external forces is more preferably ensured.

[0028] In particular, according to the fifth and twelfth aspects, since welding is not required as in the case of adopting a vacuum heat insulation structure, there is no need to worry about heat insulation failure from this point, and it is also advantageous in terms of cost.

Brief Description of the Drawings

[0029]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0030] <Overview of the Module Battery> FIG. 1 is a schematic side view of a modular battery 100 according to the present embodiment. FIG. 2 is a schematic plan view at the A1-A2 position of FIG. 1. In each figure, a right-handed XYZ coordinate system is assigned, where the horizontal direction in the front of the modular battery 100 is the X-axis direction, the direction orthogonal to the X-axis direction in the horizontal plane is the Y-axis direction, and the vertical direction is the Z-axis direction. In the modular battery 100, the negative side in the Y-axis direction is defined as the front, and the positive side in the Y-axis direction is defined as the back.

[0031] The modular battery 100 according to the present embodiment generally has an assembled battery 1G composed of a plurality of single cells 1, each of which is a sodium-sulfur battery (NaS battery). The modular battery 100 within a rectangular parallelepiped-shaped box body 2 with an opening directly above the collective battery 1G is housed in a housing space SP and has a configuration in which an opening portion that is also rectangular parallelepiped-shaped and slightly larger than the box body 2 is closed by a lid body 3 that surrounds a certain range above the box body 2 while closing the opening portion of the box body 2. That is, the box body 2 and the lid body 3 constitute a housing container for the assembled battery 1G.

[0032] Note that the gaps other than the arrangements in the housing space SP are filled with a sand material. The sand material is filled for the purpose of reducing the influence on the surroundings when problems such as breakage, abnormal heating, and leakage of the active material occur in the single cell 1. Examples of the sand material include expanded vermiculite and silica sand.

[0033] The single cell 1 is a cylindrical high-temperature operating secondary battery in which metallic sodium (Na) and sulfur (S) are used as active materials, and beta-alumina, which is a solid electrolyte having Na ion conductivity, is used as a separator for separating the two. The single cell 1 is housed in the box body 2 such that its longitudinal direction is the vertical direction.

[0034] From the center of one end (the upper end when housed in the box body 2) of the single battery 1, the negative electrode terminal 1n protrudes, and from the peripheral portion, the positive electrode terminal 1p protrudes. In the assembled battery 1G, one positive electrode terminal 1p and the other negative electrode terminal 1n of adjacent single batteries 1 are electrically connected by the connection terminal 1c, thereby forming a circuit (string) in which a plurality of single batteries 1 are connected in series. In FIG. 2, the illustration of the connection terminal 1c is omitted. Further, in the assembled battery 1G, a block is configured by connecting a plurality of strings in parallel, and a plurality of such blocks are connected in series.

[0035] Note that in the present embodiment, a case is shown in which the assembled battery 1G is configured by 25 single batteries 1, with 5 single batteries 1 arranged in the X-axis direction and 5 single batteries 1 arranged in the Y-axis direction, respectively, in a planar manner. However, this is merely an example, and the number and arrangement mode of the single batteries 1 constituting the assembled battery 1G are not limited thereto.

[0036] The box body 2 is placed and fixed on the base 4 that supports it from below. The lid body 3 is detachable from the box body 2, is placed on the box body 2 during the use of the module battery 100, and is removed from above the box body 2 when taking in and out the assembled battery 1G.

[0037] In the module battery 100 according to the present embodiment, the structures of the box body 2 and the lid body 3 that constitute the housing container are characteristic. Details of the structures of the box body 2 and the lid body 3 and the manufacturing method for realizing them will be described later.

[0038] Furthermore, the module battery 100 includes an upper duct 7 between the box body 2 and the lid body 3. More specifically, an insulating cushioning material 11 is disposed on the opening end portion 2T of the box body 2, and the upper duct 7 is placed on the cushioning material 11 and extends while bending between the opening end portion 2T of the box body 2 and the ceiling portion 3C of the lid body 3 and between the side portion 2S of the box body 2 and the side portion 3S of the lid body 3.

[0039] In addition, an electric intake fan 8 is attached to the upper duct 7. The intake fan 8 is provided to supply external air to the upper duct 7.

[0040] In addition, on each of the four side portions 2S of the box body 2 that partition the side portion of the accommodation space SP, side heaters 9a (9a1 to 9a4) are provided on the surface of the inner side surface 2ba.

[0041] Also, a bottom heater 9b is provided on the inner bottom surface 2bb of the box body 2 that partitions the bottom of the accommodation space SP.

[0042] The upper surface of the bottom heater 9b is horizontal, and the collective battery 1G is arranged on the upper surface of such bottom heater 9b. More specifically, a plate-like or sheet-like insulator 9c made of, for example, mica is interposed between the two, whereby insulation between the bottom heater 9b and the collective battery 1G is ensured.

[0043] The side heaters 9a and the bottom heater 9b are energized heating heaters provided to heat the inside of the box body 2. Typically, they are used to maintain the inside of the box body 2 at the operating temperature in order to keep the active material of each single battery 1 of the collective battery 1G in a molten state during the standby of the module battery 100 in which charging and discharging are not performed in the collective battery 1G.

[0044] <Structure of the accommodation container> Next, the structures of the box body 2 and the lid body 3 that constitute the accommodation container in the present embodiment will be described.

[0045] As shown in FIGS. 1 and 2, the box body 2 has a double structure of a metal inner box (inner container) 5 and an outer box (outer container) 6. The outer surface of the outer box 6 forms the outer surface 2a of the box body 2 (four outer side surfaces 2aa and one outer bottom surface 2ab), and the inner surface of the inner box 5 forms the inner surface 2b of the box body 2 (four inner side surfaces 2ba and one inner bottom surface 2bb) that partitions the accommodation space SP of the assembled battery 1G. And between the inner box 5 and the outer box 6 (between the outer surface 2a and the inner surface 2b), a heat insulating material 2c having electrical insulation properties (shown by hatching in FIGS. 1 and 2) is filled. Of the four side portions 2S of the box body 2, one pair of opposing side portions 2S extends along the X-axis direction, and the other pair of corresponding side portions 2S extends along the Y-axis direction.

[0046] Also, the lid body 3 has the same three-layer structure as the box body 2. That is, the lid body 3 has a double structure of a metal inner lid (inner container) 5B and an outer lid (outer container) 6B. The outer surface of the outer lid 6B forms the outer surface 3a of the lid body 3, and the inner surface of the inner lid 5B forms the inner surface 3b of the lid body 3. And between the inner lid 5B and the outer lid 6B (between the outer surface 3a and the inner surface 3b), a heat insulating material 3c having electrical insulation properties (shown by hatching in FIGS. 1 and 2) is filled. Of the four side portions 3S of the lid body 3, one pair of opposing side portions 3S extends along the X-axis direction, and the other pair of corresponding side portions 3S extends along the Y-axis direction.

[0047] As the heat insulating materials 2c and 3c, those used under an air atmosphere are adopted, and the box body 2 and the lid body 3 are configured to have an air heat insulation structure. More specifically, the box body 2 is provided in a shape and arrangement in which the outer box 6 and the inner box 5 do not contact each other through the heat insulating material 2c, and the lid body 3 is also provided in a shape and arrangement in which the outer lid 6B and the inner lid 5B do not contact each other through the heat insulating material 3c.

[0048] In the module battery 100 according to the present embodiment that adopts such an air insulation structure, heat transfer from the inner box 5 to the outer box 6 and heat transfer from the inner lid 5B to the outer lid 6B are blocked. Therefore, compared with the case of adopting a vacuum insulation structure, heat dissipation from the outer surface 2a of the box body 2 and the outer surface 3a of the lid body 3 to the outside during standby is reduced. Moreover, there is no problem that some defect occurs in the insulation structure during use and the insulation performance cannot be ensured, which is a concern in a module battery adopting a vacuum insulation structure.

[0049] From the viewpoint of ensuring sufficient heat insulation performance with an air insulation structure, the lower the thermal conductivity of the heat insulating materials 2c and 3c, the more preferable it is. It is more preferable that the thermal conductivity is 20 mW / m·K or less, which is less than half of the thermal conductivity of a general glass wool heat insulating material. In that case, the heat insulation property required for the operation of the module battery 100 can be ensured without excessively increasing the thickness of the box body 2 and the lid body 3 compared with the case where a vacuum insulation structure is adopted. The heat insulating materials 2c and 3c are provided with a thickness of about 10 mm to 50 mm.

[0050] More specifically, as shown in FIGS. 1 and 2, in the module battery 100 according to the present embodiment, a gap G2 is provided between the outer box 6 and the inner box 5 at the opening end portion (the upper end in FIG. 1) 2T of the box body 2, and a configuration in which the heat insulating material 2c is exposed to the outside from the gap G2 is adopted. Similarly, a gap G3 is provided between the outer lid 6B and the inner lid 5B at the opening end portion (the lower end in FIG. 1) 3T of the lid body 3, and a configuration in which the heat insulating material 3c is exposed to the outside from the gap G3 is adopted. As a result, a configuration in which the outer box 6 and the inner box 5, and the outer lid 6B and the inner lid 5B do not contact each other, that is, a configuration in which the two are not continuous, is realized. When the box body 2 and the lid body 3 are configured in this way, heat dissipation to the outside during standby of the module battery 100 is reduced as described above.

[0051] Furthermore, even if gas generated from the binder of the heat insulating material 2c or the like is generated when the temperature of the module battery 100 rises (especially during the first temperature rise), or when the air existing inside the box body 2 and the lid body 3 is heated and expands during use, these gases and air flow out to the outside through the gaps G2 and G3. Therefore, deformation of the box body 2 and the lid body 3 due to the retention of the generated gas or the heating expansion of the air is suppressed. If the box body 2 or the lid body 3 swells due to the retention of gas or the heating expansion of the air and comes into contact with the conductor, a ground fault may occur, or in the worst case, the box body 2 or the lid body 3 may be damaged. However, in the module battery 100 according to the present embodiment, the occurrence of such problems is preferably suppressed.

[0052] Note that the heat insulating materials 2c and 3c are preferably in a plate shape (layered), but it is not necessary to be a single sheet (single layer) in that case, and a mode in which a plurality of thin heat insulating material plates are laminated may be adopted. However, in that case, the thickness and the sizes of the gaps G2 and G3 are adjusted so that the heat insulating material plates do not protrude from the gaps G2 and G3.

[0053] Preferably, a configuration is adopted in which the outer box 6 and the inner box 5 and between the outer lid 6B and the inner lid 5B are not connected and fixed by a metal member such as a screw. In such a case, in addition to achieving heat insulation between the outer box 6 and the inner box 5 and between the outer lid 6B and the inner lid 5B, electrical insulation is also ensured. That is, the heat insulation and electrical insulation of the box body 2 and the lid body 3 are enhanced.

[0054] However, within a range that does not substantially affect the heat insulation of the box body 2 and the lid body 3, a member having a sufficiently low thermal conductivity compared to the outer box 6, the inner box 5, the outer lid 6B, and the inner lid 5B may be used to connect and fix the outer box 6 and the inner box 5 and between the outer lid 6B and the inner lid 5B to each other. In such a case, the box body 2 and the lid body 3 are reinforced.

[0055] <Fabrication of the box body> Next, the method of manufacturing the box body 2 and the lid body 3 having the above-described structure will be described. However, although the lid body 3 has different sizes (aspect ratios) for each part from the box body 2, the components are the same as those of the box body 2. Therefore, since the manufacturing method is also the same as that of the box body 2, in the following, the box body 2 will be mainly described.

[0056] FIG. 3 is a perspective view of the box body 2. In the figures after FIG. 3, the coordinate system is assigned according to the XYZ coordinate system of FIG. 1 for the completed module battery 100.

[0057] As described above, the box body 2 has an opening on one side, and a heat insulating material 2c is sandwiched between the outer box 6 and the inner box 5 on both the side part 2S and the bottom part 2B, and has a rectangular parallelepiped structure. Looking at it from another perspective, the box body 2 is composed of a metal inner box (inner container) 5 formed by connecting the plate materials forming its five inner surfaces, and is housed in a metal outer box (outer container) 6 formed by connecting the plate materials forming its five outer surfaces, and it can be considered that the box body 2 has a double box structure in which a plate-like heat insulating material 2c (hereinafter referred to as the heat insulating material plate 10) is loaded between the inner box 5 and the outer box 6. As described above, a plurality of heat insulating material plates 10 may be laminated, but hereinafter, for simplicity of explanation, it is assumed that the heat insulating material plate 10 is a single layer.

[0058] And, generally speaking, the box body 2 is manufactured by first manufacturing the inner box 5, then manufacturing the outer box 6 while loading the heat insulating material plate 10, and finally fitting the inner box 5.

[0059] Regarding the lid body 3 as well, it is considered to have a double box structure with a heat insulating material loaded inside, and the manufacturing procedure is also the same.

[0060] As shown in FIG. 3, the inner box 5 is composed of a pair of side plates 5a (5a1, 5a2) facing each other in the X-axis direction, a pair of side plates 5b (5b1, 5b2) facing each other in the Y-axis direction, and a bottom plate 5c. A total of four side plates 5a and 5b form the four inner side surfaces 2ba of the box body 2 shown in FIGS. 1 and 2, and the bottom plate 5c forms the inner bottom surface 2bb.

[0061] Further, the outer box 6 is composed of a pair of side plates 6a (6a1, 6a2) facing each other in the X-axis direction, a pair of side plates 6b (6b1, 6b2) facing each other in the Y-axis direction, and a bottom plate 6c. A total of four side plates 6a and 6b form the four outer side surfaces 2aa of the box body 2 shown in FIGS. 1 and 2, and the bottom plate 6c forms the outer bottom surface 2ab.

[0062] FIG. 4 is a view showing how the inner box 5 is assembled. As described above, the inner box 5 is composed of a pair of side plates 5a (5a1, 5a2), a pair of side plates 5b (5b1, 5b2) facing each other in the Y-axis direction, and a bottom plate 5c. Among these, the pair of side plates 5a and the bottom plate 5c are prepared in advance as an integral unit by bending a single metal plate. On the other hand, the pair of side plates 5b (5b1, 5b2) are prepared separately from the pair of side plates 5a (5a1, 5a2) and the bottom plate 5c, and are then fixed to the pair of side plates 5a.

[0063] However, at the upper ends of the pair of side plates 5a (5a1, 5a2) in the Z-axis direction, there are respectively provided bent portions 51 that are bent in the direction facing the outside of the inner box 5 in the X-axis direction. Also, at the upper ends of the pair of side plates 5b (5b1, 5b2) in the Z-axis direction, there are respectively provided bent portions 53 that are bent in the direction facing the outside of the inner box 5 in the Y-axis direction.

[0064] Furthermore, both ends of the pair of side plates 5a in the Y-axis direction are overhanging portions 52 that overhang more than the bottom plate 5c in the Y-axis direction. Also, at both ends of the pair of side plates 5b in the X-axis direction, there are provided bent portions 54 in the Y-axis direction.

[0065] The overhanging portion 52 of the side plate 5a and the bent portion 54 of the side plate 5b are respectively provided with rivet holes 52h and 54h into which a rivet 5r for fastening the side plate 5a to the side plate 5b is inserted.

[0066] The inner box 5 is completed by fixing the side plate 5b to the side plate 5a. The fixation of the two is realized by fastening the overhanging portion 52 and the bent portion 54 with a rivet 5r. Due to such fastening, a protruding portion 5p in which the overhanging portion 52 and the bent portion 54 are integrated is formed at the four corners of the inner box 5.

[0067] The bent portion 51, the bent portion 53, and the protruding portion 5p play a role in suppressing the deformation of the inner box 5 due to external forces and ensuring the strength of the inner box 5 and further the entire box body 2.

[0068] In addition, in FIG. 4, fastening with a rivet 5r is performed at two locations, above and below, of each protruding portion 5p, but the number of fastening locations with the rivet 5r is not limited to this.

[0069] When the inner box 5 is completed, then, while manufacturing the outer box 6, the entire box body 2 is manufactured. FIG. 5 is a diagram showing a state of manufacturing the entire box body 2 including the manufacturing of the outer box 6.

[0070] The outer box 6 is composed of a pair of side plates 6a (6a1, 6a2), a pair of side plates 6b (6b1, 6b2) facing each other in the Y-axis direction, and a bottom plate 6c. Similar to the inner box 5, the pair of side plates 6a and the bottom plate 6c are prepared in advance as an integral unit by bending a single metal plate. On the other hand, the pair of side plates 6b (6b1, 6b2) are prepared separately from the side plates 6a (6a1, 6a2) and the bottom plate 6c and are then fixed to the pair of side plates 6a.

[0071] However, at the upper ends of the pair of side plates 6a (6a1, 6a2) in the Z-axis direction, there are provided bent portions 61 that are bent in the direction toward the inside of the outer box 6 in the X-axis direction. Also, at the upper ends of the pair of side plates 6b (6b1, 6b2) in the Z-axis direction, there are provided bent portions 63 that are bent in the direction toward the inside of the outer box 6 in the Y-axis direction.

[0072] Furthermore, both ends of the pair of side plates 6a in the Y-axis direction are overhanging portions 62 that protrude more than the bottom plate 6c in the Y-axis direction. Also, at both ends of the pair of side plates 6b in the X-axis direction, there are provided bent portions 64 in the Y-axis direction.

[0073] In the overhanging portion 62 of the side plate 6a and the bent portion 64 of the side plate 6b, there are respectively provided rivet holes 62h, 64h into which a rivet 6r for fastening the side plate 6a to the side plate 6b is inserted.

[0074] The outer box 6 is completed by fastening the side plate 6b to the side plate 6a with rivets as described above. However, prior to such fastening, heat insulating material plates 10 (10a1, 10a2, 10b1, 10b2, 10c) are respectively arranged at positions between the outer box 6 and the inner box 5 in the box body 2.

[0075] Specifically, first, the heat insulating material plate 10c is arranged on the bottom plate 6c that is continuous with the side plate 6a, and further, the heat insulating material plates 10a1 and 10a2 are arranged along each of the pair of side plates 6a (6a1, 6a2). FIG. 5 shows a state in which these heat insulating material plates 10c, 10a1, and 10a2 are already arranged.

[0076] Subsequently, the heat insulating material plates 10b1 and 10b2 are respectively arranged so as to be in contact with the surfaces perpendicular to the Y-axis of the heat insulating material plate 10c and the heat insulating material plates 10a1 and 10a2 arranged previously.

[0077] Subsequently, side plates 6b1 and 6b2 are respectively disposed between the overhanging portions 62 of side plates 6a1 and 6a2 at both ends in the Y-axis direction of side plates 6a1 and 6a2, and the bent portions 64 of side plates 6b1 and 6b2 are respectively overlapped with the overhanging portions 62 of side plates 6a1 and 6a2.

[0078] Then, by driving rivets 6r into the coaxial rivet holes 62h and 64h, side plates 6b1 and 6b2 are fastened to side plates 6a1 and 6a2. By such fastening, a protruding portion 6p in which the overhanging portion 62 and the bent portion 64 are integrated is formed at the four corners of the outer box 6. Thus, the outer box 6 is completed with the heat insulating material plate 10 disposed along the inner surface.

[0079] Note that the bent portions 61, 63, and the protruding portion 6p also play a role in suppressing deformation of the outer box 6 due to external force and ensuring the strength of the outer box 6 and further the entire box body 2.

[0080] Finally, the inner box 5 is inserted into the space inside the outer box 6 surrounded by the heat insulating material plate 10 from above. Thus, the box body 2 is completed. In other words, after the heat insulating material plate 10 is disposed along the inner surface of the outer box 6, the inner box 5 is fitted into the rectangular parallelepiped space partitioned by the heat insulating material plate 10, thereby obtaining the box body 2.

[0081] From the above manufacturing procedure, it is clear that the box body 2 provided in the module battery 100 according to the present embodiment has a structure in which the outer box 6 and the inner box 5 do not come into contact with each other at all.

[0082] Also, in the obtained box body 2, the heat insulating material plate 10 is exposed only between the bent portion 51 of the side plate 5a of the inner box 5 and the bent portion 61 of the side plate 6a of the outer box 6, and between the bent portion 53 of the side plate 5b of the inner box 5 and the bent portion 63 of the side plate 6b of the outer box 6. That is, they become the gap G2 between the outer box 6 and the inner box 5 of the box body 2.

[0083] Moreover, the bent portions 51 and 53 of the inner box 5 are respectively formed by bending the side plates 5a and 5b, and the bent portions 61 and 63 of the outer box 6 are respectively formed by bending the side plates 6a and 6b. Therefore, they also play a role in ensuring the strength against deformation of the inner box 5 or the outer box 6 respectively.

[0084] That is, the bent portions 51 and 53 of the inner box 5 and the bent portions 61 and 63 of the outer box 6, together with the protruding portions 5p and 6p described above, play a role in ensuring the strength of the box body 2 without bringing the outer box 6 into contact with the inner box 5.

[0085] Note that the bent portions 51 and 53 of the inner box 5 and the bent portions 61 and 63 of the outer box 6 are preferably provided such that the size of the gap G2 is 8 mm or more. In such a case, the outflow of gas from the gap G2 is facilitated. On the other hand, from the viewpoint of suitably holding the heat insulating material plate 10, the bent portion needs to have a width of at least 1 mm or more.

[0086] For example, when using a heat insulating material plate 10 with a thickness of 10 mm as the heat insulating material 2c, the width of the bent portion is determined to be 1 mm. On the other hand, when using a heat insulating material plate 10 with a thickness of 50 mm, the width of the bent portion can be selected from the range of 1 mm to 21 mm.

[0087] Furthermore, although detailed description is omitted, as described above, the lid body 3 having the same configuration as the box body 2 is also manufactured by the same procedure. In other words, the lid body 3 generally has a rectangular parallelepiped outer lid (outer container) 6B corresponding to the outer box 6 of the box body 2 and a rectangular parallelepiped inner lid ( inside container) 5B corresponding to the inner box 5 of the box body 2, and has a configuration in which a plate-shaped heat insulating material similar to the heat insulating material plate 10 is loaded as the heat insulating material 3c therebetween. Therefore, similar to the box body 2, the lid body 3 is configured such that the outer lid 6B and the inner lid 5B do not come into contact with each other at all.

[0088] Moreover, a gap G3 is provided between the bent portions of the outer lid 6B and the inner lid 5B, and the outer lid 6B and the inner lid 5B are each provided with a protruding portion similar to that of the outer box 6 and the inner box 5, so that the strength against the expansion of air inside the lid body 3 during operation and deformation due to external force is ensured.

[0089] The gap G3 of the lid body 3 is also preferably provided with a size of 8 mm or more, similar to the gap G2 of the box body 2. In such a case, the outflow of gas from the gap G3 is facilitated.

[0090] Also, the bent portions of the outer lid 6B and the inner lid 5B may be provided with the same width as the bent portions of the outer box 6 and the inner box 5 of the box body 2. Note that the bent portions of the outer lid 6B and the inner lid 5B also serve to prevent the heat insulating material 3c from coming out of the lid body 3, for example, the heat insulating material 3c falling off during use.

[0091] As described above, according to the present embodiment, in a module battery in which a plurality of single cells, which are high-temperature operating secondary batteries such as NaS batteries, are connected and housed in a housing container, both the box body and the lid body constituting the housing container are configured with an air heat insulation structure in which a heat insulating material is filled between an outer container (outer box, outer lid) and an inner container (inner box, inner lid), both made of metal plates, and the outer container and the inner container are not in contact with each other. Thus, heat transfer from the inner container to the outer container is blocked, so that heat dissipation from the surface of the outer container to the outside during standby of the module battery is reduced compared to the case of adopting a vacuum heat insulation structure. In addition, the problem of poor heat insulation during use, which is a concern when adopting a vacuum heat insulation structure, does not occur.

[0092] Moreover, since the fixing of the metal plates constituting the box body and the lid body is performed by fastening with rivets, welding as in the case of adopting a vacuum heat insulation structure is not required. From this point of view, there is no need to worry about poor heat insulation, and it is also advantageous in terms of cost. Note that, from the viewpoint of making the fixing of the metal plates stronger and more reliable, a mode of using both rivet fastening and welding is acceptable.

[0093] Also, by providing a gap where the heat insulating material is exposed only at the opening end between the outer box and the inner box, it is possible to prevent gas generated from the binder of the heat insulating material, etc. from staying inside the box body or the lid body during temperature rise (especially during the first temperature rise), or to prevent the box body and the lid body from deforming as the air existing inside the box body and the lid body expands due to heating during the use of the module battery.

[0094] Furthermore, by providing a bent portion at each of the outer box and the inner box of the box body and the outer lid and the inner lid of the lid body at the opening end, and by providing a protruding portion at each of the four corners of each of the outer box and the inner box of the box body and the outer lid and the inner lid of the lid body, the strength of the box body and the lid body against deformation caused by external force is ensured.

Example

[0095] An experiment was conducted to confirm the heat retention performance of the module battery 100 according to the above-described embodiment. As the module battery 100 of the example, one having a width of 0.8 m, a length of 1.0 m, a height of 0.8 m, and a weight of about 400 kg, which accommodates 25 single cells 1 in the arrangement shown in FIG. 3, was prepared. The capacities of the side heater 9a and the bottom heater 9b were set to about 1.5 kW / 200V.

[0096] Also, as a comparative example, a module battery having the same configuration as the module battery 100 of the example was prepared, except that the inner box 5 and the outer box 6 of the box body 2 were made continuous without providing the gap G2, and the inner lid 5B and the outer lid 6B of the lid body 3 were made continuous without providing the gap G3.

[0097] The heaters (side heater 9a and bottom heater 9b) of the module batteries of the example and the comparative example were continuously energized and heated for 24 hours. The internal control temperature of the battery was set to 305°C. The ambient temperature was 25°C. That is, the temperature difference between the inside and outside of the battery was 280°C.

[0098] FIG. 6 is a graph showing the relationship between the heating time and the integrated heater power quantity during such heating. From such a graph, when the average power was obtained, it was 532 W in the example, whereas it was 573 W in the comparative example.

[0099] The results show that in the module battery according to the examples, a reduction in heat dissipation of approximately 40 W is achieved compared to the comparative examples.

Claims

1. A box body that houses a plurality of single cells, each of which is a high-temperature operating secondary battery, A lid that closes the opening of the box body, A housing container for a module battery, comprising: The box body and the lid body are A rectangular parallelepiped inner container and outer container, both of which are made of metal plates, A heat insulating material loaded between the inner container and the outer container, Having an air heat insulation structure, In each of the box body and the lid body, The inner container and the outer container do not contact each other, The heat insulating material is exposed only at the opening end, A housing container for a module battery, characterized by this.

2. A housing container for a module battery according to Claim 1, At each opening end of the box body and the lid body, a first bent portion bent from the side plate of the inner container and a second bent portion bent from the side plate of the outer container form a gap, and the heat insulating material is exposed from the gap. A housing container for a module battery, characterized by this.

3. A housing container for a module battery according to Claim 2, The thickness of the heat insulating material is 10 mm or more and 50 mm or less, The gap is 8 mm or more, The widths of the first bent portion and the second bent portion are 1 mm or more, A housing container for a module battery, characterized by this.

4. A housing container for a module battery according to any one of Claims 1 to 3, Each of the outer container and the inner container of the box body and the lid body is provided with a protruding portion at each of the four corners, where one overhanging portion and the other bent portion of the side plates perpendicular to each other are integrated. A container for housing a modular battery.

5. A container for the module battery according to claim 4, In the protruding portion, the mutually perpendicular side plates are fixed to each other by rivets. A container for housing a modular battery.

6. A container for housing the module battery according to claim 2 or 3, The insulation material is formed by laminating a plurality of insulation plates, and the gap is smaller than the thickness of the insulation plates. A container for housing a modular battery.

7. A container for housing the module battery according to any one of claims 1 to 6, The thermal conductivity of the insulating material is 20 mW / m K or less. A container for housing a modular battery.

8. A plurality of cells, each of which is a high-temperature operating secondary battery; A box body that houses the plurality of unit cells; A lid that closes an opening of the box; A module battery having The box body and the lid body, A rectangular parallelepiped inner container and an outer container, both of which are made of metal plates; A heat insulating material is inserted between the inner container and the outer container; The air insulation structure comprises: In each of the box body and the lid body, The inner container and the outer container do not come into contact with each other, The insulating material is exposed only at the open end. A module battery characterized by:

9. The battery module according to claim 8, At each of the opening ends of the box body and the lid body, a first bent portion bent from the side plate of the inner container and a second bent portion bent from the side plate of the outer container form a gap, and the heat insulating material is exposed from the gap. A module battery characterized by this.

10. The module battery according to claim 9, wherein the thickness of the heat insulating material is 10 mm or more and 50 mm or less, the gap is 8 mm or more, and the widths of the first bent portion and the second bent portion are 1 mm or more. A module battery characterized by this.

11. The module battery according to any one of claims 8 to 10, wherein each of the outer container and the inner container of the box body and the lid body is provided with a protruding portion at each of the four corners, in which one overhanging portion and the other bent portion of the side plates orthogonal to each other are integrated. A module battery characterized by this.

12. The module battery according to claim 11, wherein in the protruding portion, the side plates orthogonal to each other are fixed with rivets. A module battery characterized by this.

13. The module battery according to claim 9 or claim 10, wherein the heat insulating material is formed by laminating a plurality of heat insulating material plates, and the gap is smaller than the thickness of the heat insulating material plate. A module battery characterized by this.

14. The module battery according to any one of claims 8 to 13, wherein the thermal conductivity of the heat insulating material is 20 mW / m·K or less. A module battery characterized by this.

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