Battery pack

Abstract

The invention provides a battery pack capable of suppressing generation of fire leakage from a side surface of an exterior case. A battery pack (100) is provided with: one or more secondary battery cells (1) having a safety valve provided to a part of an outer can; a resin exterior case (10) that houses the one or more secondary battery cells (1) and has a first surface and a second surface that intersects the first surface; a heat-resistant plate (40) disposed on the inner surface of the first surface of the exterior case (10) so as to face the safety valve of the secondary battery cell (1); and a bent sheet (50) having a first sheet (51) and a second sheet (52) connected to the first sheet (51). The second sheet (52) is bent from the first sheet (51), and the first sheet (51) faces the first surface and the second sheet (52) faces the second surface in a state where the bent sheet (50) is disposed at an end of the heat-resistant plate (40).

Description

Technical Field

[0001] The present disclosure relates to a battery pack. Background Art

[0002] In order to use rechargeable secondary batteries such as lithium-ion secondary batteries to drive electrical equipment, a battery pack that houses secondary battery cells in an outer casing is used (for example, Patent Document 1). In such a battery pack, each secondary battery cell is provided with a safety valve, which is used to discharge high-temperature and high-pressure gas from the outer tank in the event that some abnormality occurs and the interior of the outer tank becomes high-pressure. For example, in a secondary battery cell using a cylindrical outer tank, the safety valve is generally provided on the end face of the cylinder. In a battery pack using such secondary battery cells, the following structure is desired: when the safety valve is opened and high-temperature and high-pressure gas is ejected from the secondary battery cell, even if the gas ignites and generates flames, it will not leak outside the outer casing of the battery pack.

[0003] In e.g. Figure 8 In the battery pack 800 composed of the resin outer casing 810 as shown in the schematic cross-sectional view of , a heat-resistant plate 840 such as a metal plate is arranged on the end surface of the secondary battery cell 801. Thus, even if high-temperature and high-pressure gas is discharged from the safety valve 801a of the secondary battery cell 801, the heat-resistant plate 840 can prevent flames from penetrating the resin outer casing 810.

[0004] However, it was found that the high-temperature and high-pressure flame ejected from the end face of the secondary battery cell 801 was blocked by the heat-resistant plate 840 and bounced back, and the direction was changed to the side and went straight, which might melt the side of the resin outer casing 810 and leak the flame to the outside. In order to avoid such a situation, a method of covering the entire outer casing with a sheet made of silica or making the outer casing a heat-resistant metal casing is considered, but both methods have the problems of high cost, increase in weight and size, etc.

[0005] Prior Art Literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 2021-174673 Summary of the invention

[0008] Problems to be solved by the invention

[0009] One of the objects of the present disclosure is to provide a battery pack that suppresses fire leakage from the side surface of an outer casing.

[0010] Means for solving problems

[0011] A battery pack according to one embodiment of the present invention comprises: one or more secondary battery cells, a safety valve being provided on a portion of an outer can; a resin outer shell which accommodates the one or more secondary battery cells and has a first surface and a second surface intersecting the first surface; and a heat-resistant plate which is arranged on the inner surface of the first surface of the outer shell in a posture opposite to the safety valve of the secondary battery cell, the battery pack also comprises a bending piece which has a first piece and a second piece connected to the first piece, the second piece being bent from the first piece, and the first piece being opposite to the first surface and the second piece being opposite to the second surface when the bending piece is arranged at the end of the heat-resistant plate.

[0012] Effects of the Invention

[0013] According to a battery pack involved in one embodiment of the present invention, a bending piece bent from the first surface to the second surface is arranged on the inner surface of the outer shell. Therefore, even if high-pressure gas is released from the safety valve into the outer shell, the gas is rebounded by the heat-resistant plate arranged on the first surface toward the second surface, the side of the outer shell can be protected by the bending piece, thereby suppressing flame leakage from the outer shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a perspective view of the battery pack according to the first embodiment.

[0015] Figure 2 yes Figure 1 Longitudinal section view at line II-II.

[0016] Figure 3 yes Figure 1 Cross-sectional view at line III-III.

[0017] Figure 4 yes Figure 1 Cross-sectional view at line IV-IV.

[0018] Figure 5 yes Figure 1 An exploded perspective view of the battery pack.

[0019] Figure 6 Viewed from the rear side obliquely downward Figure 5 An exploded perspective view of the battery pack.

[0020] Figure 7 yes Figure 3 An enlarged cross-sectional view of the main parts.

[0021] Figure 8 It is a schematic cross-sectional view showing a state in which fire occurs in a battery pack according to a comparative example.

[0022] Fig. 9 This is a schematic cross-sectional view showing a state in which fire leakage is suppressed in the battery pack according to the first embodiment.

[0023] Fig.10 It is shown in Figure 6 An exploded three-dimensional view showing a state in which a bending piece is arranged on the inner surface of the upper shell.

[0024] Fig.11 This is an enlarged cross-sectional view of a main part of the battery pack according to the second embodiment.

[0025] Fig.12 This is an enlarged cross-sectional view of a main part of a battery pack according to the third embodiment.

[0026] Fig.13 This is an enlarged cross-sectional view of a main part of a battery pack according to a fourth embodiment. DETAILED DESCRIPTION

[0027] The aspects of the present invention can also be identified by the following structures and features.

[0028] In the battery pack according to another aspect of the present invention, in the above aspect, the outer casing has a rectangular outer shape.

[0029] The bent piece protects the rectangular corners of the outer case.

[0030] In a battery pack according to another aspect of the present invention, in any of the above aspects, the folded piece is formed of a metal plate folded into an L-shape.

[0031] Furthermore, in a battery pack according to another aspect of the present invention, in any of the above aspects, the folded piece is formed by integrally forming the first piece and the second piece.

[0032] Furthermore, in a battery pack according to another aspect of the present invention, in any of the above aspects, a surface of the secondary battery cell provided with a safety valve is separated from the heat-resistant plate on the inner surface of the first surface of the outer case to form a gas discharge space.

[0033] The second piece is formed longer than the height of the gas discharge space. According to the above configuration, by forming the bent piece longer than the gas discharge space formed between the end surface of the secondary battery cell and the heat-resistant plate, the side surface of the resin outer case can be reliably protected.

[0034] Furthermore, in a battery pack according to another aspect of the present invention, in any of the above aspects, one or more convex shapes are provided on the inner surface of the outer case.

[0035] The surface of the bent piece is formed into a concave shape corresponding to the convex shape.

[0036] Furthermore, in another embodiment of the present invention, in any of the above embodiments, the bending sheet forms the first sheet and the second sheet in a continuous curved manner. According to the above structure, by guiding high-temperature and high-pressure gas from the first surface to the second surface along the curved surface, it is expected that the pressure and impact of the gas can be alleviated.

[0037] Furthermore, in a battery pack according to another aspect of the present invention, in any of the above aspects, the bent piece is formed integrally with an end portion of the heat-resistant plate.

[0038] Hereinafter, the embodiments of the present invention will be described based on the accompanying drawings. However, the embodiments shown below are examples for concretizing the technical ideas of the present invention, and the present invention is not limited to the following modes. In addition, this specification does not identify the components shown in the scope of the request as the components of the embodiments. In particular, the size, material, shape, relative configuration, etc. of the structural parts recorded in the embodiments, as long as there is no special specificity, are not intended to limit the scope of the present invention to only this, but are simple illustrative examples. In addition, the size, positional relationship, etc. of the components shown in the drawings are sometimes exaggerated in order to make the description clear. Further, in the following description, the same name and symbol represent the same or homogeneous components, and detailed description is appropriately omitted. Further, the elements constituting the present invention can be formed by the same components to form multiple elements in the form of one component sharing multiple elements, or on the contrary, multiple components can share the function of one component to achieve.

[0039] The battery pack of the present invention can be used as a driving power source for autonomous walking robots for door-to-door delivery, electric carts for door-to-door delivery, electric scooters for golf courses, construction machinery, hybrid vehicles, electric vehicles and other vehicles. In addition to the driving power source for power-assisted bicycles, it can also be used as a power source for portable electrical equipment such as wireless devices, electric cleaners, and electric tools. Or it can also be used as a backup power source for servers, a power supply device for home use, office use, and factory use in a fixed power storage purpose. Below, as one embodiment of the present invention, a battery pack used as a driving power source for an autonomous walking robot is described.

[0040] [Implementation Method 1]

[0041] The battery pack 100 according to the first embodiment of the present invention is shown in FIG. Figure 1 to Figure 7 In these figures, Figure 1 A perspective view showing a battery pack 100 according to Embodiment 1 is shown. Figure 2 Show Figure 1 The longitudinal section view at line II-II, Figure 3 Show Figure 1 The cross-sectional view at line III-III, Figure 4 Show Figure 1 The cross-sectional view at line IV-IV of Figure 5 Show Figure 1 An exploded perspective view of a battery pack 100 , Figure 6 Shown is a view from the rear side obliquely downward Figure 5 An exploded perspective view of a battery pack 100 , Figure 7 Show Figure 3 The battery pack 100 shown in these figures includes an outer case 10 , a label 20 , and one or more secondary battery cells 1 .

[0042] (External casing 10)

[0043] The outer casing 10 accommodates the battery module 2 composed of one or more secondary battery cells 1 and the circuit board 3. Figure 1 to Figure 6 As shown in FIG. 1 and FIG. 2 , the outer casing 10 is formed into a box-shaped rectangular shape in a plan view, which is extended in one direction. The box-shaped outer casing 10 has a first surface and a second surface intersecting the first surface. Figure 1 In the example of FIG. 1 , the top surface is set as the first surface, and the side surface along the long side direction is set as the second surface. Figure 2 to Figure 6 As shown in FIGS. 1 and 1B , a storage space for storing the battery module 2 and the circuit board 3 is provided inside the outer casing 10 .

[0044] For example, Figure 5 , Figure 6 As shown, the outer casing 10 is divided into an upper casing 11 and a lower casing 12. The divided upper casing 11 and the lower casing 12 are fixed at their corners by screwing, fitting, bonding, ultrasonic welding, etc. Figure 6 In the example, the upper shell 11 and the lower shell 12 are screwed together, and an O-ring 16 is interposed between the upper shell 11 and the lower shell 12 to achieve waterproof performance. Figure 6 In the example, the upper shell 11 is set to a box shape with an opening on the lower surface, and the lower shell 12 is set to a plate-shaped bottom panel. The upper shell 11 includes a top plate 11a, a side panel 11b connected along the long side direction around the top plate 11a, and an end panel 11c connected along the short side direction around the top plate 11a. The inner surface of the top plate 11a constitutes the first surface. In addition, the inner wall of the side panel 11b constitutes the second surface. A pair of side panels 11b and a pair of end panels 11c constitute the side wall 11d of the outer shell 10. In addition, in addition to forming the top plate 11a and the side wall 11d integrally, the upper shell 11 can also constitute the top plate and the side wall by independent components. For example, it can be configured so that the side wall is a frame shape with openings at the top and bottom, and the top plate is fixed to the frame-shaped side wall. In addition, the top plate 11a is formed in a partially protruding shape, and the circuit substrate 3 is stored in this part.

[0045] In addition, a plurality of ribs 11e are separately provided on the side panel 11b. Each rib 11e extends along the thickness direction of the upper shell 11, and contributes to the reinforcement of the upper shell 11. Figure 1 In the examples of FIG. 1 and FIG. 2 , the ribs 11e are not provided on the end panel 11c, but it is obvious that the ribs may be provided on the end panel. Figure 6 As shown, a threaded hole 11f for fixing the lower housing 12 is opened on the end surface of each rib 11e.

[0046] Furthermore, if Figure 5 , Figure 6 As shown in FIG. 1 and FIG. 2 , the upper case 11 has bosses 11 g formed at a total of six locations at the corners and the middle of the long sides of the rectangular upper case 11 . The bosses 11 g are provided with screw holes 11 h for fixing the battery module 2 .

[0047] The outer case 10 is preferably made of a member having excellent insulating properties, for example, a resin such as polycarbonate or PC-ABS alloy.

[0048] (Secondary battery cell 1)

[0049] One or more secondary battery cells 1 can use secondary battery cells whose outer cans are made into square or cylindrical shapes. Figure 2 , Figure 3 In the example shown, 120 cylindrical secondary battery cells 1 are arranged in a vertical position. In addition, the secondary battery cells 1 are set to be connected in series with 10 and in parallel with 12. In addition, the number or configuration of the secondary battery cells, the number of connections in series or in parallel, etc. are not limited to this example, and any number and configuration can be appropriately adopted. Each secondary battery cell 1 has a positive and negative electrode. The positive and negative electrodes are preferably provided on one end surface of the secondary battery cell 1. Such a secondary battery cell 1 can appropriately utilize known secondary batteries such as lithium-ion secondary batteries, nickel-metal hydride batteries, and nickel-cadmium batteries.

[0050] In addition, if Figure 7 As shown in FIGS. 1 and 2 , a safety valve 1a is provided in the outer can of the secondary battery cell 1. The safety valve 1a opens in response to an increase in the internal pressure of the outer can, and releases the gas inside the outer can to the outside.

[0051] The battery module 2 includes a battery holder that accommodates a plurality of secondary battery cells 1. The battery holder is provided with a plurality of storage tubes that individually accommodate the secondary battery cells 1. Such a battery holder can be made of a resin such as polycarbonate having excellent insulating properties.

[0052] (Circuit board 3)

[0053] The battery module 2 is connected to the circuit board 3 via a lead plate. The circuit board 3 is mounted with a charge and discharge circuit for charging and discharging the secondary battery cells 1, a protection circuit for monitoring the voltage and temperature of the secondary battery cells 1 and cutting off the current in the event of an abnormality, etc. The circuit board 3 is made of a glass epoxy substrate or the like.

[0054] (Exhaust hole 13)

[0055] On the other hand, Figure 5 As shown, a part of the outer casing 10 is formed with a vent hole 13, which is used to release the high-pressure gas to the outside when the safety valve of the secondary battery cell 1 is opened and the high-pressure gas is discharged. Here, the vent hole 13 is formed in the label attachment area 14 where the label 20 is attached, and the vent hole 13 is blocked by attaching the label 20. The vent hole 13 is offset to one side of the upper surface of the outer casing 10 (at Figure 5 In addition, the exhaust hole 13 is not limited to being provided on the upper surface of the outer casing 10, and may also be provided on the side surface, the bottom surface, etc. In addition, the exhaust hole 13 may be opened at multiple locations. The exhaust hole 13 is designed according to the volume of the outer casing 10, the battery capacity of the secondary battery cell 1, etc., and is set to 12 mm wide, for example.

[0056] (Tag 20)

[0057] The label 20 is adhered to the periphery of the exhaust hole 13 of the outer shell 10 and attached to the label attachment area 14 of the outer shell 10. The label attachment area 14 is formed on a step portion 15 that is one level lower than other areas of the outer shell 10 so as to be roughly flush with the surface of the label 20. The label 20 is pre-printed with information such as the specifications of the battery pack 100, such as the model or manufacturer name, battery capacity, and rating. The label 20 is made of a resin such as polycarbonate or polypropylene, or a member in which a paper base is impregnated or coated with a resin. The outer shape of the label 20 is set to be rectangular. Figure 5 In the examples of FIG. 1 and FIG. 2 , the label 20 is formed into a horizontally long rectangular shape with chamfered corners, but the shape is not limited to this shape and may be formed into a vertically long or square shape or a polygonal shape such as an octagonal shape.

[0058] (Double-sided tape 30)

[0059] In order to attach the label 20, the back side of the label 20 has an adhesive surface at least partially. Figure 6 As shown, a double-sided tape 30 is attached around the label 20, and an adhesive surface is attached to the label 20. The double-sided tape 30 is a member for fixing the label 20 at a position to block the exhaust hole 13. For example, the thickness of the label 20 is set to 0.5 mm, and the thickness of the double-sided tape 30 is set to 0.2 mm. In addition, the double-sided tape 30 is not limited to the double-sided tape 30, and an adhesive or the like may be used for bonding the label 20.

[0060] (Heat-resistant plate 40)

[0061] In addition, the battery pack 100 includes a heat-resistant plate 40. The heat-resistant plate 40 is disposed on the inner surface of the first surface of the outer casing 10 in a posture facing the safety valve of the secondary battery cell 1. The heat-resistant plate 40 is formed in a plate shape that covers the end surface of each secondary battery cell 1 when a plurality of secondary battery cells 1 are arranged. Figure 4 , Figure 7 In the example shown in the cross-sectional view of , a heat-resistant plate 40 is arranged on the lower surface of the circuit substrate 3. However, the present disclosure is not limited to this structure, and for example, the bottom surface of the substrate holder holding the circuit substrate may also be used as the heat-resistant plate, and such a heat-resistant plate 40 is made of a heat-resistant material such as mica or ceramic.

[0062] (Bending piece 50)

[0063] Furthermore, the battery pack 100 is provided with a bending piece 50 at the end of the heat-resistant plate 40. The bending piece 50 has a first piece 51 and a second piece 52 connected to the first piece 51. The bending piece 50 makes the first piece 51 face the first surface and makes the second piece 52 face the second surface on the inner surface of the outer shell 10. The first piece 51 and the second piece 52 are preferably formed integrally. Here, the bending piece 50 bends the first piece 51 and the second piece 52 from the first surface along the second surface. In addition, the first piece and the second piece may be separately formed, and the second piece may be joined to the first piece to form the bending piece.

[0064] The bent piece 50 is made of a heat-resistant member. With such a structure, even if high-temperature and high-pressure gas is released from the safety valve and rebounded by the heat-resistant plate 40 arranged on the first surface toward the second surface, the side of the outer casing 10 can be protected by the bent portion 50, thereby preventing flames from leaking from the outer casing 10. Figure 8-Figure 9 This situation will be described.

[0065] like Figure 8As in the battery pack 800 involved in the comparative example shown, by configuring the heat-resistant plate 840 to cover the end surface of the secondary battery cell 801, even if the high-temperature and high-pressure gas is discharged from the safety valve 801a provided on the end surface of the secondary battery cell 801, the heat-resistant plate 840 can be used to prevent the flame from leaking from the upper surface of the outer casing 810. However, through the experiment of the inventor, it was found that the high-temperature and high-pressure gas ejected from the end surface of the secondary battery cell 801 is blocked by the heat-resistant plate 840 and does not move upward, and as a result, it moves straight in the horizontal direction and collides with the side of the outer casing 810; and when the gas ignites and generates flames, it is possible to melt the side of the outer casing 810 and the flame leaks to the outside. In order to avoid such a situation, it is considered to make the material of the outer casing 810 metal instead of resin, or to improve the heat resistance of the outer casing 810 by covering it with a fire-resistant sheet made of silica. However, these methods all lead to high costs, weight, and size increases.

[0066] In contrast, in the battery pack 100 according to the present embodiment, Figure 7 As shown in FIG. 1 , a bending piece 50 is arranged which is bent from the first surface to the second surface of the outer casing 10. Fig. 9 As shown in the schematic cross-sectional view, even if high-temperature and high-pressure gas is ejected from the safety valve 1a of the secondary battery cell 1, the side panel 11b of the outer casing 10 is protected by the second sheet 52 from the high-temperature and high-pressure gas and flame that are blocked by the heat-resistant plate 40 and move in the lateral direction, and the flame is prevented from leaking to the outside from there. As a result, the entire outer casing 10 is not made into a heat-resistant structure, but the part that may be exposed to the high-temperature and high-pressure gas is efficiently covered, achieving a reduction in component cost and weight reduction.

[0067] Such a bending piece 50 is made of a member having heat resistance, for example, a metal plate, mica, ceramics, etc. The bending piece 50 is preferably formed by bending a metal plate into an L-shape.

[0068] exist Figure 7 In the example of the embodiment of the present invention, the surface of the secondary battery cell 1 provided with the safety valve 1a is separated from the heat-resistant plate 40 on the first surface inside the outer casing 10 to form a gas discharge space 42. In this state, the length L2 of the second piece 52 of the bent piece 50 is preferably formed to be longer than the height L1 of the gas discharge space 42. According to this structure, the side surface of the outer casing 10 can be reliably protected.

[0069] In addition, Figure 7 , Fig.10In the example shown in FIG. 1 , a bent piece 50 is arranged on the inner surface of the outer casing 10 so as to cover the corner located at the junction of the top plate 11a and the side plate 11b. Thus, by reinforcing the corner with the bent portion 50, it is prevented that high-temperature and high-pressure gas and flames gather at the corner inside the outer casing 10 and break.

[0070] In addition, Figure 6 , Fig.10 In the example shown, since the upper shell 11 is provided with a step, the height of the corner portion is different at the front and rear. Therefore, the height of the bent piece 50 also changes at the front and rear according to the step shape of the upper shell 11. As described above, the second piece 52 is formed so that its lower end covers the gas discharge space 42 and is longer than the gas discharge space 42. The gas discharge space 42 is defined by the end face of the secondary battery cell 1. In addition, Figure 5 In the example of , the heights of the end faces of all the secondary battery cells 1 are aligned. Therefore, the heights of the lower ends of the second pieces 52 of each bending piece 50 are also aligned accordingly. On the other hand, regarding the height of the upper end of the second piece 52, as described above, since a part of the upper shell 11, i.e., the rear section side, is protruded, the height of the corner portion constituting the boundary between the first surface and the second surface is also different accordingly. Therefore, the result of designing the length of the second piece 52 according to the height of the corner portion is that the bending piece 50a arranged on the front side is formed lower, and the bending piece 50b arranged on the rear side is formed higher.

[0071] Meanwhile, the battery pack 100 defines a gas guide path inside the outer case 10 for guiding the gas exhausted from the safety valve of the secondary battery cell 1 to the gas exhaust hole 13. The bent piece 50 can also be used to define the gas guide path.

[0072] In addition, the outer casing 10 may have one or more convex shapes on its inner surface. The bent piece 50 can be closely attached to the inner surface of the outer casing 10 having the convex shape by forming a concave shape corresponding to the convex shape, thereby reliably protecting the outer casing 10. Figure 6 , Fig.10 In the example of , a plurality of ribs 11e are provided on the inner surface of the upper shell 11. Correspondingly, a concave shape 53 is formed on the second piece 52 of the bending piece 50. Thus, the bending piece 50 can be brought into close contact with the inner surface of the outer shell 10. In addition, the concave shape 53 can also achieve the effect of positioning the bending piece 50 on the inner surface of the outer shell 10. Furthermore, the advantage of being able to improve the physical strength of the bending piece 50 can also be achieved. In addition, by forming concave and convex on the surface of the bending piece 50 exposed to high temperature and high pressure gas, it is also possible to expect the effect of causing pressure loss in the gas and reducing the pressure.

[0073] In addition, in the above example, an example is shown in which the concave shape 53 is provided on the second piece 52 side in the bending piece 50, but it is self-evident that the concave shape can also be provided on the first piece side according to the shape of the outer shell. Furthermore, it is not limited to the concave shape, and any shape such as a convex shape can be added to the bending piece according to the shape of the outer shell.

[0074] [Implementation Method 2]

[0075] In the above Figure 3 In the example of the embodiment of FIG. 4 , the bending piece 50 is arranged at the end of the heat-resistant plate 40, and a gap is provided between the heat-resistant plate 40 and the bending piece 50. However, the present disclosure is not limited to this embodiment, and for example, Fig.11 As shown in the battery pack 200 according to the second embodiment, a gap is not provided between the heat-resistant plate 40B and the bent piece 50B. In this figure, the same reference numerals are given to the same components as those of the battery pack 100 according to the first embodiment, and detailed descriptions are omitted as appropriate. Thus, it is possible to prevent high-temperature and high-pressure gas from leaking from between the heat-resistant plate 40B and the bent piece 50B.

[0076] [Implementation method 3]

[0077] In addition, the bent piece may be formed integrally with the end of the heat-resistant plate. That is, the bent portion may be provided integrally with the heat-resistant plate. Such an example is shown as a battery pack 300 according to Embodiment 3. Fig.12 . In this figure, the same reference numerals are given to the same components as those of the battery packs according to the above-mentioned embodiments, and detailed descriptions are omitted as appropriate. With such a structure, the joint between the heat-resistant plate 40C and the bending piece 50C can be completely eliminated, thereby preventing gas leakage from this portion. Since the end of the heat-resistant plate 40C can be bent to form the bending piece 50C, there is no need to prepare a bending piece as an independent component, and manufacturing costs can also be reduced.

[0078] [Implementation Method 4]

[0079] Furthermore, the bending piece 50 does not need to form the first piece 51 and the second piece 52 at a right angle, but can also be bent. Such an example is shown as a battery pack 400 involved in Embodiment 4. Fig.13 In this figure, the same reference numerals are given to the same components as those of the battery pack according to the above-described embodiments, and detailed descriptions thereof are appropriately omitted. Fig.13 The bent piece 50D shown connects the first piece 51D and the second piece 52D in a curved manner, and the bent piece 50D bent from the first surface to the second surface can be arranged on the inner surface of the outer casing 10. According to such a structure, by guiding the high-temperature and high-pressure gas from the first surface to the second surface along the curved surface, the effect of relieving the pressure and impact of the gas can be expected.

[0080] In the above example, the inner surfaces of both sides of the side surface of the outer casing 10 are shown. Figure 5 In the example, the left and right sides of the battery module 2 are provided with a bent piece 50, respectively. The present disclosure is not limited to this structure. Figure 5 In the embodiment, the bent pieces may be respectively arranged on the front and rear surfaces of the battery module 2. Thus, the risk of fire when the secondary battery cell runs away can be reduced for the entire side surface including the front and rear surfaces of the outer casing 10.

[0081] In the above example, the battery pack is installed in the electrical device to be driven to supply power to the electrical device. In addition, in the case where the remaining capacity of the battery pack decreases or the battery pack deteriorates over the years, the battery pack can be replaced and the electrical device can continue to be used. However, the present invention does not limit the battery pack to a replaceable battery pack that mainly accommodates secondary battery cells, but can also be applied to a form in which secondary battery cells are accommodated in the housing of the electrical device. In the present disclosure, a battery pack only needs to accommodate secondary battery cells in the housing, and a structure in which a secondary battery cell for driving is built into the housing of the electrical device itself is also referred to as a battery pack. That is, the present invention is not limited to replaceable battery packs, but can also be applied to electrical equipment with built-in secondary battery cells.

[0082] Industrial Applicability

[0083] The battery pack of the present invention can be used as a driving power source for autonomous walking robots for door-to-door delivery, electric carts for door-to-door delivery, electric scooters for golf courses, construction machinery, hybrid vehicles, electric vehicles, etc. In addition, in addition to the driving power source for power-assisted bicycles, it can also be appropriately used for power sources for portable electrical equipment such as wireless devices, electric cleaners, and electric tools, backup power sources for servers in fixed power storage applications, and power supply devices for home, office, and factory use.

[0084] Explanation of symbols

[0085] 100, 200, 300, 400...Battery pack

[0086] 1…Secondary battery cell; 1a…Safety valve

[0087] 2…Battery Module

[0088] 3…Circuit board

[0089] 10…External housing

[0090] 11…upper shell; 11a…top plate; 11b…side panel; 11c…end panel; 11d…side wall; 11e…rib; 11f…threaded hole; 11g…boss; 11h…threaded hole

[0091] 12…Lower housing

[0092] 13…Exhaust hole

[0093] 14…Label attachment area

[0094] 16…O-ring

[0095] 20… Tags

[0096] 40, 40B, 40C, 40D…heat-resistant plate

[0097] 42…Gas exhaust space

[0098] 50, 50B, 50C, 50D... bending pieces; 50a... bending piece arranged on the front side; 50b... bending piece arranged on the rear side

[0099] 51, 51D…the first film

[0100] 52, 52D…The second film

[0101] 53…concave shape

[0102] 800…Battery Pack

[0103] 801…Secondary battery cell; 801a…Safety valve

[0104] 810…External housing

[0105] 840…Heat-resistant plate

[0106] L1…Height of the gas exhaust space

[0107] L2…length of the second piece.

Claims

1. A battery pack comprising: One or more secondary battery cells, with a safety valve provided on a portion of the outer can; an outer casing made of resin, accommodating the one or more secondary battery cells, and having a first surface and a second surface intersecting the first surface; and A heat-resistant plate is disposed on the inner surface of the first surface of the outer casing so as to face the safety valve of the secondary battery cell. The battery pack further includes a bending piece, the bending piece including a first piece and a second piece connected to the first piece. The second sheet is bent from the first sheet, In a state where the bent piece is arranged at an end portion of the heat-resistant plate, the first piece is opposed to the first surface, and the second piece is opposed to the second surface.

2. The battery pack according to claim 1, wherein: The outer casing is configured to be rectangular in shape. The bent piece protects the rectangular corners of the outer case.

3. The battery pack according to claim 1, wherein: The bent piece is formed of a metal plate bent into an L-shape.

4. The battery pack according to claim 1, wherein: The bent piece integrally forms the first piece and the second piece.

5. The battery pack according to any one of claims 1 to 4, wherein: On the inner surface of the first surface of the outer case, the surface of the secondary battery cell provided with the safety valve is separated from the heat-resistant plate to form a gas discharge space. The second piece is formed to be longer than the height of the gas exhaust space.

6. The battery pack according to any one of claims 1 to 4, wherein: One or more convex shapes are provided on the inner surface of the outer shell. The surface of the bent piece is formed into a concave shape corresponding to the convex shape.

7. The battery pack according to any one of claims 1 to 4, wherein: The bending piece is formed by bending the first piece and the second piece continuously.

8. The battery pack according to any one of claims 1 to 4, wherein: The bent piece is formed integrally with an end portion of the heat-resistant plate.

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