Battery pack

Abstract

An insertion gap is provided in a partition wall formed between battery cells, and a plate material is simply and reliably inserted into the insertion gap and held in a fixed position. A battery pack is provided with a plurality of battery cells (1), a battery holder (2) provided with partition walls (22), and a heat-resistant plate (13) inserted into the partition walls (22). The partition wall forms an insertion gap (14) in which the heat-resistant plate (13) is disposed between the pair of holding wall portions (23). The pair of holding wall sections (23) form pressing protrusions (17) on facing surfaces (16) facing the heat-resistant plate (13). In a cross section of the partition wall, the pressing protrusion (17) is provided with: a pair of first protrusions (17A) formed on one of the opposing surfaces so as to be spaced apart in the width direction; and a second protruding section (17B) which is located between the pair of first protruding sections (17A) and is formed on the other facing surface, and which holds the heat-resistant plate (13) at a fixed position at which the heat-resistant plate (13) is inserted in the gap (14) by elastically deforming either the heat-resistant plate (13) or the pressing protruding section (17).

Description

Technical Field

[0001] The present invention relates to a battery pack obtained by connecting a plurality of battery cells in series or in parallel to increase the capacity. Background Art

[0002] As a power source for portable devices or wireless devices, a battery pack in which a plurality of battery cells are housed in a case can be used. The battery pack increases the capacity by connecting a plurality of battery cells in series or in parallel. In particular, in recent years, on the one hand, a high-capacity battery pack is required, and on the other hand, from the viewpoints of portability of the battery pack, etc., it is also required to be small and lightweight. Thus, the high-capacity of each battery cell is still being promoted, and in addition, inside the battery pack, a configuration in which the battery cells are arranged without gaps is adopted.

[0003] On the other hand, a battery cell sometimes causes thermal runaway due to various reasons such as internal short circuit or overcharging. In a state where a plurality of battery cells are arranged, if any one of the battery cells abnormally generates heat and catches fire, the adjacent battery cells will be heated and thermal runaway will be induced, and sometimes this situation will spread and cause thermal runaway of a plurality of battery cells. Therefore, it is required to be configured such that even if one of the battery cells abnormally generates heat, it does not affect other battery cells.

[0004] In addition, in order to dispose the battery cells at fixed positions, a plastic holder is used for the battery pack. The holder is formed into a structure that guides and disposes each battery cell at a fixed position. Although the holder can dispose the battery cells at fixed positions, it cannot withstand the temperature of the abnormally heated battery cell and melts. The melting of the holder becomes a cause of spreading of fire because the holder cannot separate the battery cells adjacent to the abnormally heated battery cell.

[0005] In order to solve the above problems, the applicant of the present invention has developed a battery pack (refer to Patent Document 1) that is configured to house a plurality of battery cells in a plastic holder and can avoid the induction of thermal runaway. The battery pack includes: a plurality of battery cells; and a holder that disposes the battery cells in a parallel posture, and the holder has partition walls that dispose the battery cells at fixed positions between adjacent battery cells. The partition walls are formed of a resin molding layer having a shape that disposes the battery cells at fixed positions with the opposing surface to the battery cells, and are integrally formed with the holder by synthetic resin, and a non-melting plate is disposed inside, and a three-layer structure is formed by laminating resin molding layers on both surfaces of the non-melting plate. The battery pack is configured as follows: an insertion gap for disposing the non-melting plate at a fixed position is provided inside the resin molding layer of the holder, and the non-melting plate is disposed in the insertion gap.

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Re-Publication No. 2019 / 208217 Summary of the Invention

[0009] Problems to be Solved by the Invention

[0010] The above battery pack has the following characteristics: a plurality of battery cells are arranged at fixed positions by means of a holder, and the holder and a non-melting plate can be used to avoid the induction of thermal runaway of the battery cells. In particular, the above battery pack will achieve the following characteristics: the holder for arranging a plurality of battery cells at fixed positions is an integral structure of plastic and can be mass-produced at low cost, and the holder can effectively prevent the induction of thermal runaway.

[0011] However, in the structure where an insertion gap is provided in the partition wall of the resin-molded holder as described above and a plate material such as a non-melting plate is arranged in the insertion gap, there is a problem that it is very difficult to adjust the interval of the insertion gap. This is because there are manufacturing errors in the internal shape of the insertion gap of the partition wall having a resin-molded layer, and there are also manufacturing errors in the external shape of the plate material inserted into the insertion gap. If the insertion gap is too narrow, it will take time or become impossible to insert the plate material. On the contrary, if the insertion gap is too wide, the inserted plate material will easily pass through the insertion gap and cannot be held in a fixed position, and there are problem points such as the inserted plate material falling off from the holder in the manufacturing process. In addition, in the case of a holder in which the gap between adjacent battery cells is narrowed, it is difficult to form an insertion gap for inserting a plate material in view of the draft angle of the mold for forming the insertion gap in the holder.

[0012] The present invention is an invention developed for the purpose of solving the above disadvantages. One of the objects of the present invention is to provide a battery pack that resin-molds a holder capable of accommodating a plurality of battery cells, and an insertion gap is provided in the partition wall formed between the battery cells, and a plate material can be simply and reliably inserted into the insertion gap and held in a fixed position.

[0013] Means for Solving the Problems

[0014] A battery pack according to an aspect of the present invention includes: a plurality of battery cells; a battery holder that arranges the plurality of battery cells in a parallel posture and has partition walls disposed between the mutually adjacent battery cells; and a heat-resistant plate that is inserted inside the partition walls of the battery holder and is disposed between adjacent battery cells. The partition wall has a pair of holding wall portions that face the adjacent battery cells respectively, and an insertion gap for arranging the heat-resistant plate at a fixed position is formed between the pair of holding wall portions. On the opposing surfaces of the pair of holding wall portions that face the heat-resistant plate disposed in the insertion gap, pressing convex portions for pressing the heat-resistant plate are respectively formed. In the cross-section of the partition wall, the pressing convex portion includes: a pair of first convex portions that are formed separately in the width direction on one of the opposing surfaces; and a second convex portion that is located between the pair of first convex portions and is formed on the other opposing surface. The battery pack elastically deforms either the heat-resistant plate inserted in the insertion gap or the pressing convex portion, and presses the heat-resistant plate from both sides with the pair of first convex portions and the second convex portion, thereby holding the heat-resistant plate at a fixed position in the insertion gap.

[0015] Advantages of the Invention

[0016] The battery pack according to the present invention has the following advantages: The battery holder capable of accommodating a plurality of battery cells is resin-molded, and an insertion gap is provided in the partition wall formed between the battery cells, so that a plate can be simply and reliably inserted into the insertion gap and held at a fixed position. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is an external perspective view of a battery pack showing an embodiment of the present invention.

[0018] Figure 2 It shows Figure 1 a perspective view of the manufacturing process of the battery pack.

[0019] Figure 3 It is Figure 2 an exploded perspective view of the battery assembly of the battery pack.

[0020] Figure 4 It is to Figure 3 show an exploded perspective view of the battery holder of the battery assembly after being disassembled.

[0021] Figure 5 It is Figure 2 a sectional view taken along line V-V of the battery assembly shown.

[0022] Figure 6 It is Figure 5 a partially enlarged sectional view taken along line VI-VI of the battery assembly shown.

[0023] Figure 7 It is Figure 5Partial enlarged sectional view taken along line VII-VII of the battery assembly shown.

[0024] Figure 8 It is a partial enlarged longitudinal sectional view showing the insertion gap.

[0025] Figure 9 It is a partial enlarged transverse sectional view showing the insertion gap.

[0026] Figure 10 It is an enlarged sectional view showing the state where the heat-resistant plate to be elastically deformed is inserted into the insertion gap.

[0027] Figure 11 It is an enlarged transverse sectional view showing the state where the plate is inserted into the battery holder of the reference example.

[0028] Figure 12 Is Figure 11 An enlarged sectional perspective view of the battery holder shown. Detailed implementation

[0029] First, an aspect of the present invention will be described. In a battery holder that houses a plurality of battery cells, when an insertion gap is provided in the partition wall formed between the battery cells and a plate having excellent heat resistance and insulation is inserted into the insertion gap, as described above, there is a problem that it is difficult to adjust the interval of the insertion gap. In view of such a problem, the inventors of the present invention have made Figure 11 And Figure 12 The battery holder 902 having the structure shown in the reference example of. In Figure 11 And Figure 12 In the battery holder 902 shown, the partition wall 922 disposed between adjacent battery cells 901 is constituted by a pair of holding wall portions 923, and an insertion gap 914 for inserting a plate 913 is formed between the pair of holding wall portions 923. On the opposing surface 916 of the pair of holding wall portions 923 that faces the plate 913 disposed in the insertion gap 914, a plurality of rows of ridges 917 for respectively abutting against the plate 913 to hold it are provided extending in the length direction of the insertion gap 914. In the cross section of the partition wall 922, the plurality of rows of ridges 917 are constituted by a pair of ridges 917 formed separately in the width direction on one opposing surface 916 and a pair of ridges 917 formed separately in the width direction on the other opposing surface 916, and are configured to hold the same position of the plate 913 in a state of being sandwiched from both sides by the opposing ridges 917. Since this structure causes the ridges 917 to protrude from the opposing surface 916 of the pair of holding wall portions 923 that form the insertion gap 914 to hold, there is a tendency to easily hold the plate compared to a structure without ridges.

[0030] However, in Figure 11 AndFigure 12 In the structure shown, since the same position of the plate 913 is supported from both sides by the convex strips 917, there is a problem that it becomes difficult to adjust the height of the convex strips 917. That is, in this structure, if the interval between the opposed convex strips 917 is too narrow, it takes a long time to insert the plate 913 or it becomes impossible to insert it. On the contrary, if the interval between the opposed convex strips 917 is too wide, the inserted plate 913 will pass through the insertion gap 914 and cannot be held in a fixed position, and the problem that the inserted plate 913 falls off the battery holder 902 during the manufacturing process cannot be solved. In view of the above actual situation, it is important to seek optimization of the structure for holding the plate inserted into the insertion gap, and to explore a structure for easily and simply inserting the plate into the insertion gap and reliably holding the plate in a fixed position.

[0031] A battery pack according to a certain aspect of the present invention includes: a plurality of battery cells; a battery holder that arranges the plurality of battery cells in a parallel posture and includes partition walls disposed between adjacent battery cells; and a heat-resistant plate that is inserted into the inside of the partition walls of the battery holder and is disposed between adjacent battery cells. The partition wall has a pair of holding wall portions respectively opposed to adjacent battery cells, and an insertion gap for disposing the heat-resistant plate in a fixed position is formed between the pair of holding wall portions. On the opposed surfaces opposed to the heat-resistant plate disposed in the insertion gap, the pair of holding wall portions are respectively formed with pressing convex portions for pressing the heat-resistant plate. In a cross section of the partition wall, the pressing convex portion includes: a pair of first convex portions that are formed separately in the width direction on one opposed surface; and a second convex portion that is located between the pair of first convex portions and is formed on the other opposed surface, causing either the heat-resistant plate inserted into the insertion gap or the pressing convex portion to elastically deform, and pressing the heat-resistant plate from both sides with the pair of first convex portions and the second convex portion, thereby holding the heat-resistant plate in a fixed position in the insertion gap.

[0032] According to the above battery pack, the following advantages are obtained: By providing an insertion gap in the partition wall formed between the battery cells, the plate can be easily and reliably inserted into the insertion gap and held in a fixed position. This is because: the partition wall of the battery holder of the above battery pack has an insertion gap for disposing the heat-resistant plate in a fixed position between a pair of holding wall portions opposed to the battery cells, and the pair of holding wall portions are respectively provided with pressing convex portions on the opposed surfaces opposed to the heat-resistant plate. The pressing convex portion is composed of a pair of first convex portions and a second convex portion in a cross section of the partition wall. The pair of first convex portions are formed separately in the width direction on one opposed surface, and the second convex portion is located between the pair of first convex portions and is formed on the other opposed surface, causing either the heat-resistant plate inserted into the insertion gap or the pressing convex portion to elastically deform, and pressing the heat-resistant plate from both sides with the pair of first convex portions and the second convex portion, thereby holding the heat-resistant plate in a fixed position in the insertion gap.

[0033] As described above, an insertion gap is provided between a pair of holding wall portions, a pair of first convex portions formed separately in the width direction are provided on one opposed surface where the insertion gap is formed, and a second convex portion is provided on the other opposed surface so as to be located between the pair of first convex portions. Since the first convex portion and the second convex portion are arranged at non-opposed positions, the heat-resistant plate is not pressed at the same position from both sides, but different positions of the heat-resistant plate can be pressed from both sides. Therefore, even if the protruding amounts of the first convex portion and the second convex portion are set to be large so that the area interfering with the heat-resistant plate becomes large, the interference portion between the heat-resistant plate and the pressing convex portion can be absorbed by elastically deforming the heat-resistant plate or the pressing convex portion, and the heat-resistant plate can be inserted simply and easily. In addition, in the state where the heat-resistant plate has been inserted, since the heat-resistant plate is pressed from both sides by the first convex portion and the second convex portion, it can be reliably held in a fixed position.

[0034] In another aspect of the battery pack of the present invention, the battery holder may be provided with an insertion gap so as to penetrate the partition wall in the longitudinal direction of the battery cell, a pressing convex portion may be provided on the opposed surface so as to be located at the central portion in the longitudinal direction of the insertion gap, and one open end of the insertion gap may be used as an insertion port for inserting the heat-resistant plate.

[0035] According to the above configuration, by providing an insertion gap penetrating in the longitudinal direction of the battery cell in the partition wall and setting one open end of the insertion gap as the insertion port for the heat-resistant plate, the heat-resistant plate can be inserted simply and easily, and the central portion of the heat-resistant plate can be reliably held by the pressing convex portion provided at the central portion of the insertion gap.

[0036] In another aspect of the battery pack of the present invention, the battery holder may be divided into two parts in the middle in the longitudinal direction of the battery cell. One divided holder has an insertion port at one end of the insertion gap and a pressing convex portion at the other end.

[0037] According to the above configuration, since the battery holder is divided and the pressing convex portion is provided only in the insertion gap provided in one of the divided holders, the battery holder can be made into a simple structure.

[0038] In another aspect of the battery pack of the present invention, the insertion gap may include a holding gap and an expansion gap. The holding gap is provided with the pressing convex portion, the expansion gaps are provided on both sides of the holding gap and are formed to have a width wider than that of the holding gap. The transverse width of the holding gap is set to be narrower than the transverse width of the heat-resistant plate, and both side portions of the heat-resistant plate are arranged in the expansion gaps.

[0039] According to the above configuration, the following advantages are achieved: Since the insertion gap of the partition wall has expansion gaps formed on both sides of the holding gap provided with the pressing protrusions and having a width interval wider than that of the holding gap, when inserting the heat-resistant plate that undergoes elastic deformation into the insertion gap, it is possible to deform it into a posture bent in the lateral width direction while guiding both side portions of the heat-resistant plate that has been elastically deformed into a bent posture to the expansion gaps and insert it well.

[0040] In another aspect of the battery pack of the present invention, the pair of first protrusions and the second protrusion may have inclined surfaces with a gradually decreasing protruding height toward the insertion port.

[0041] According to the above configuration, the following advantages are achieved: Since the pair of first protrusions provided on one opposed surface and the second protrusion provided on the other opposed surface have inclined surfaces with a gradually decreasing protruding height toward the insertion port, the front end of the heat-resistant plate inserted from the insertion port can be smoothly guided along the inclined surface between the pair of first protrusions and the second protrusion.

[0042] In another aspect of the battery pack of the present invention, the pair of first protrusions may be ridges extending in the length direction of the insertion gap, and the ridges have inclined surfaces with a gradually decreasing protruding height toward the insertion port.

[0043] According to the above configuration, by providing the pair of first protrusions provided on one opposed surface of the insertion gap as ridges extending in the length direction of the insertion cylinder portion and providing inclined surfaces with a gradually decreasing protruding height on the ridges, the heat-resistant plate inserted from the insertion port can be smoothly inserted in a low-resistance state with the pair of ridges as guiding members. In particular, by moving the front end of the heat-resistant plate inserted into the insertion gap along the inclined surface of the ridge, the heat-resistant plate can be smoothly guided and moved on the upper surface of the ridge.

[0044] Hereinafter, embodiments of the present invention will be described with reference to the drawings. However, the embodiments shown below are examples for embodying the technical idea of the present invention, and the present invention is not limited to the following embodiments. In addition, this specification is by no means a specification that specifies the components shown in the technical solution as the components of the embodiments. In particular, the dimensions, materials, shapes, relative configurations, etc. of the constituent parts described in the embodiments are, unless otherwise specifically stated, not intended to limit the scope of the present invention only to these embodiments, but are merely illustrative examples. Furthermore, the sizes or positional relationships of the components shown in each drawing may be exaggerated for clarity of explanation. In addition, in the following description, the same names and reference numerals denote the same or homogeneous components, and detailed descriptions are appropriately omitted. In addition, each element constituting the present invention may also be configured as follows: a plurality of elements are constituted by the same component and one component serves as a plurality of elements, and conversely, the functions of one component may be shared and implemented by a plurality of components.

[0045] The battery pack of the present invention can be used as a power source for electric devices such as speakers, electric cleaners, and power tools, or as a standby power source for servers or a power supply device for home, business, or factory use in a stationary energy storage application, or even as a driving power source for assisting bicycles, electric locomotives, electric forklifts, or as a driving power source for vehicles such as hybrid vehicles or electric vehicles. Hereinafter, as an embodiment of the present invention, a battery pack used as a power source for a wireless speaker will be described.

[0046] [Embodiment 1]

[0047] The battery pack 100 of Embodiment 1 of the present invention is shown in Figures 1 to 9 . Figure 1 is a perspective view showing the appearance of the battery pack, Figure 2 is a perspective view showing Figure 1 the manufacturing process of the battery pack, Figure 3 is a perspective view showing the disassembled state of the battery assembly of Figure 2 after removing the removal guide plate, Figure 4 is a perspective view showing the disassembled state of the battery holder of the battery assembly of Figure 3 , Figure 5 is a sectional view taken along line V-V of the battery assembly shown in Figure 2 , Figure 6 and Figure 7 are sectional views taken along line VI-VI and VII-VII of the battery assembly shown in Figure 5 , Figure 8 and Figure 9It is a partially enlarged longitudinal sectional view and a partially enlarged transverse sectional view showing the insertion gap.

[0048] The battery pack 100 shown in these figures includes: a plurality of battery cells 1; a battery holder 2 that arranges these battery cells 1 in a parallel posture at fixed positions and has partition walls 22 disposed between adjacent battery cells; and a heat-resistant plate 13 that is inserted inside the partition wall 22 of the battery holder 2 and is disposed between adjacent battery cells 1.

[0049] (Battery assembly 10)

[0050] In Figures 1 to 7 In the battery pack 100 shown, a plurality of battery cells 1 are housed in the battery holder 2 in a parallel posture and arranged at fixed positions, and a heat-resistant plate 13 is inserted inside the partition wall 22 disposed between adjacent battery cells 1 and arranged at a fixed position. Then, a guide plate 3 is fixed to both end faces of the battery holder 2, and a circuit board 4 is arranged on the upper part of the battery holder 2 to form a battery assembly 10. The upper surface of the battery assembly 10 is covered with an insulating member 6, and the surface is covered with an exterior sheet 7.

[0051] (Battery cell 1)

[0052] The battery cell 1 can use a cylindrical battery cell with a cylindrical outer can. As an example, the battery cell 1 has the following structure: an electrode body is housed in a metal and cylindrical outer can, electrolyte is filled, and the opening of the outer can is hermetically sealed with a sealing plate. The battery cell 1 is provided with end face electrodes 11 at both ends in the length direction. The electrodes provided at both end faces, that is, the bottom face of the outer can and the central part of the sealing plate, are positive and negative electrodes. In the battery cell 1 in the figure, the first electrode 11A is formed by a convex electrode arranged at the central part of the sealing plate, and the other end face electrode 11 is used as the second electrode 11B and is formed by the bottom face electrode of the outer can.

[0053] A battery cell 1 like this can appropriately use a non-aqueous electrolyte secondary battery with high energy efficiency, such as a lithium-ion secondary battery. However, the battery pack of the present invention does not specify the battery cell as a lithium-ion secondary battery. All rechargeable batteries, such as nickel-metal hydride batteries or nickel-cadmium batteries, can be used for the battery cell.

[0054] (Battery holder 2)

[0055] The battery holder 2 holds a plurality of battery cells 1 in a fixed position. The battery holder 2 has a holding cylinder portion 20 that houses the battery cell 1 inside and covers the outer peripheral surface of the battery cell 1. The battery holder 2 in the figure has a plurality of holding cylinder portions 20 that house the plurality of battery cells 1 in a parallel posture. The battery holder 2 in the figure holds the plurality of battery cells 1 in a posture parallel to each other in the length direction and with the end face electrodes 11 at both ends arranged in the same plane. The battery holder 2 is resin-molded into a shape connecting the plurality of holding cylinder portions 20. The battery holder 2 is preferably made of a material with excellent insulation, heat resistance, and flame retardancy, such as a resin such as polycarbonate or ABS.

[0056] The battery holder 2 in the figure has a box-shaped outer shape and arranges a plurality of battery cells 1 in multiple layers and multiple columns. The battery holder 2 that houses the plurality of battery cells 1 in multiple layers and multiple columns is molded into a shape connecting the plurality of holding cylinder portions 20 in multiple layers and multiple columns. In addition, the battery holder 2 has a partition wall 22 disposed between the battery cells 1 housed adjacent to each other. As shown in the figure, the battery holder 2 that houses the plurality of battery cells 1 in multiple layers and multiple columns is provided with a partition wall 22 between the adjacent battery cells 1, and the region forming the outer side surface of the battery holder 2 is formed by the holding cylinder portion 20. As Figure 3 shown, the battery holder 2 has the end face electrodes 11 of the battery cells 1 disposed on the first face 2A and the third face 2C of the battery holder 2 having a box-shaped outer shape.

[0057] Figure 4 And Figure 5 The shown battery holder 2 is formed by connecting eight holding cylinder portions 20 in a parallel posture into a shape of four layers and two columns, and making the inside of the holding cylinder portion 20 almost equal to the outer shape of the battery cell 1 as the battery housing portion 21. The battery holder 2 in the figure arranges eight battery cells 1 in four layers and two columns and holds them in a posture arranged vertically, horizontally, left, and right in the figure. The battery holder 2 in the figure arranges eight battery cells 1 in a matrix shape in a posture symmetric about the left and right in the front view. This structure has the following advantages: The battery holder 2 for arranging the battery cells 1 in multiple layers can be held in a stable upright posture. The number or arrangement of the battery cells 1 is not limited to this configuration, and it can also be set to a structure having seven or fewer or nine or more battery cells 1. In addition, in addition to being arranged in a matrix shape, it can also be arranged in a staggered manner in an alternating manner in each layer. The illustrated battery pack 100 is formed in a configuration arrangement in which eight battery cells 1 are arranged in two columns in the horizontal direction and overlapped in four layers in the vertical direction, but the battery pack is not a configuration that specifies the arrangement of the plurality of battery cells or the installation posture of the battery pack.

[0058] The battery holder 2 in the figure arranges the battery cells 1 in a configuration of 4 layers and 2 columns. Therefore, between the eight battery cells 1 arranged vertically, horizontally, and in all directions, a cross-shaped partition wall 22 is provided vertically. The partition wall 22 has an insertion gap 14 inside for inserting the heat-resistant plate 13. This battery block 10 can prevent the situation of inducing thermal runaway in adjacent battery cells 1 when any one of the battery cells 1 is in a state of thermal runaway and abnormal heating.

[0059] Figure 4 The battery holder 2 is divided into two split holders composed of a first split holder 2X and a second split holder 2Y in the longitudinal direction of the battery cell 1. The battery holder 2 in the figure integrally forms an end panel portion 26 at one end of the split holding cylinder portion 20, and the first split holder 2X and the second split holder 2Y with the other end as an opening are connected to each other at the opening and arranged in a battery storage portion 21 for internally storing the battery cell 1. The first split holder 2X and the second split holder 2Y are provided with a cylindrical battery storage portion 21 for inserting and arranging the cylindrical battery cell 1 in a fixed position. The internal shape of the battery storage portion 21 is formed to be almost equal to the external shape of the battery cell 1, and more precisely, it is formed slightly larger so that the battery cell 1 can be smoothly inserted and arranged in a fixed position. This battery holder 2 can smoothly insert the slender battery cell 1. The first split holder 2X and the second split holder 2Y are separately manufactured by resin molding and are connected to each other by inserting the battery cell 1. The first split holder 2X and the second split holder 2Y of this structure are connected to each other in a fixed position via the battery cell 1 in a state where both ends of the battery cell 1 are inserted.

[0060] In addition, the first split holder 2X and the second split holder 2Y are connected by a locking structure. Figure 4 The second split holder 2Y of the has locking hooks 27 integrally formed at the central portions of both side surfaces, i.e., the second surface 2B and the fourth surface 2D, and the central portions of the upper surface and the lower surface, extending axially outward of the holding cylinder portion 20. The first split holder 2X is provided with a locking portion 28 for guiding the locking hooks 27 at the opposing position. The first split holder 2X and the second split holder 2Y are connected to each other so as not to separate by connecting the locking hooks 27 to the locking portion 28.

[0061] (Heat-resistant plate 13)

[0062] Figures 4 to 7The battery assembly 10 shown has a heat-resistant plate 13 disposed inside a partition wall 22 between adjacent battery cells 1. The heat-resistant plate 13 is a plate that does not deform at the temperature of an abnormally heated battery cell 1, and an inorganic plate such as a mica plate is preferably used. Instead of a mica plate, an inorganic plate obtained by sintering or shaping inorganic powder into a plate shape, or a plate-shaped inorganic material or a plate obtained by shaping inorganic fibers into a plate shape can be used. Further, in order to prevent short-circuiting between adjacent battery cells when the resin forming the battery holder melts due to an abnormally heated battery cell 1, the heat-resistant plate uses a member having insulation properties. Therefore, the heat-resistant plate 13 can also be a sheet member made of aramid resin or a ceramic plate, etc. The heat-resistant plate 13 uses a plate slightly thinner than the insertion gap 14 so that it can be detachably disposed in the insertion gap 14.

[0063] (Partition wall 22, Insertion gap 14)

[0064] The partition wall 22 has a pair of holding wall portions 23 respectively opposed to adjacent battery cells 1, and an insertion gap 14 for disposing the heat-resistant plate 13 in a fixed position is formed between the pair of holding wall portions 23. The partition wall 22 disposes the heat-resistant plate 13 inside the pair of holding wall portions 23, and is formed into a three-layer structure of the heat-resistant plate 13 and the holding wall portions 23. The partition wall 22 is formed into a structure in which the holding wall portions 23 are laminated so as to be opposed to both surfaces of the internal heat-resistant plate 13. The surface of the holding wall portion 23 is formed into a curved surface along the surface of the cylindrical battery cell 1, and the battery cell 1 is disposed in a fixed position. Here, Figure 4 , Figure 6 and Figure 7 Since the battery holder 2 shown is divided into a first divided holder 2X and a second divided holder 2Y in the longitudinal direction of the battery cell 1, the insertion gap 14 of the partition wall 22 formed in the battery holder 2 is also divided into a first insertion gap 14X formed in the first divided holder 2X and a second insertion gap 14Y formed in the second divided holder 2Y. The first insertion gap 14X and the second insertion gap 14Y are formed in the opposed partition walls 22 of the first divided holder 2X and the second divided holder 2Y, and are configured such that in a state where the first divided holder 2X and the second divided holder 2Y are connected, the first insertion gap 14X and the second insertion gap 14Y are linearly arranged to form an insertion gap 14 into which the heat-resistant plate 13 can be inserted. That is, the insertion gap 14 of the battery holder 2 is formed by the first insertion gap 14X and the second insertion gap 14Y so as to be able to accommodate the entire length of the heat-resistant plate 13 in a state where the first divided holder 2X and the second divided holder 2Y are connected. Further, as Figure 9 shown, the inner width (H) and the minimum interval (Dm) of the insertion gap 14 are determined in consideration of the lateral width (W) and thickness (t) of the inserted heat-resistant plate 13.

[0065] (Pressing convex part 17)

[0066] A pair of holding wall parts 23 are respectively provided with pressing convex parts 17 for pressing the heat-resistant plate 13 integrally formed on the opposing surfaces 16 facing the heat-resistant plate 13 in order to hold the heat-resistant plate 13 inserted into the insertion gap 14 in a fixed position. As Figure 9 shown in the enlarged sectional view of, the pressing convex part 17 has a pair of first convex parts 17A and a second convex part 17B. Under the cross-section of the partition wall 22, the pair of first convex parts 17A are formed separately in the width direction on one opposing surface, that is, the first opposing surface 16A, and the second convex part 17B is located between the pair of first convex parts 17A and is formed on the other opposing surface, that is, the second opposing surface 16B.

[0067] In this way, with the structure of supporting the heat-resistant plate 13 by the pair of first convex parts 17A provided on the first opposing surface 16A and the second convex part 17B located between the pair of first convex parts 17A and provided on the second opposing surface 16B, since the first convex part 17A and the second convex part 17B are arranged at non-opposing positions, different positions of the heat-resistant plate 13 can be pressed from both sides. Therefore, even if the protruding amounts of the first convex part 17A and the second convex part 17B are set to be large, the interference part between the heat-resistant plate 13 and the pressing convex part 17 can be absorbed, and the heat-resistant plate 13 can be inserted simply and easily. This is because: in the elastically deformable heat-resistant plate 13, as Figure 10 shown, the heat-resistant plate 13 itself can be inserted into the insertion gap 14 while bending in the width direction to relieve the interference with the pressing convex part 17, or by pressing different positions on both sides of the heat-resistant plate 13 with the first convex part 17A and the second convex part 17B facing the heat-resistant plate 13, the first convex part 17A and the second convex part 17B can be effectively elastically deformed to absorb the interference with the heat-resistant plate 13. Therefore, according to this structure, the heat-resistant plate 13 can be inserted simply and easily via the elastically deformed heat-resistant plate 13 and the pressing convex part 17, and in the state where the heat-resistant plate 13 has been inserted, the heat-resistant plate 13 can be reliably held in a fixed position by pressing the heat-resistant plate 13 from both sides with the first convex part 17A and the second convex part 17B.

[0068] In Figure 6 and Figure 7 the battery holder 2 shown, the insertion gap 14 is provided in a state of penetrating the partition wall 22 in the length direction of the battery cell 1, and the pressing convex part 17 is provided on the opposing surfaces 16 of the pair of holding wall parts 23 so as to be located at the central part in the length direction of the entire insertion gap 14 formed by the first insertion gap 14X and the second insertion gap 14Y, and one open end of the insertion gap 14 is used as an insertion port 15 for inserting the heat-resistant plate 13. Figure 6 and Figure 7The battery holder 2 shown is divided in the longitudinal direction. At one end of the first insertion gap 14X of one of the divided holders, i.e., the first divided holder 2X, an insertion port 15 is provided, and a pressing convex portion 17 is provided at the other end. The structure is as follows: In the second insertion gap 14Y of the other divided holder, i.e., the second divided holder 2Y, instead of a pressing convex portion 17, a through hole that uniformly penetrates the partition wall 22 is provided as the second insertion gap 14Y. Additionally, considering the relationship of the draft angle of the mold for forming the insertion gap 14 in the battery holder 2, it is more ideal to provide the pressing convex portion 17 at the central portion of the insertion gap 14. That is, since the mold for forming the insertion gap 14 in the battery holder 2 is inserted from both ends of the battery unit 1 in the longitudinal direction of the first divided holder 2X and the second divided holder 2Y, it is possible to easily provide the pressing convex portion 17 at the central portion of the insertion gap 14. In particular, since the first divided holder 2X forms the insertion port 15 as the insertion portion of the mold (the formed through hole), in the structure where the pressing convex portion 17 is formed at the end opposite to the insertion port 15, it is also convenient for the structure of forming the inclined surface described later.

[0069] A pair of first convex portions 17A formed on the first opposed surface 16A are as Figures 6 to 8 shown, formed as a convex strip 17x extending in the longitudinal direction of the insertion gap 14, and formed spanning from the open end of the first insertion gap 14X to the middle portion of the first insertion gap 14X. The convex strip 17x has an inclined surface 17a whose protruding height gradually decreases toward the insertion port 15. That is, the pair of first convex portions 17A are not formed at the insertion port 15, but are formed near the connecting portion of the first divided holder 2X and the second divided holder 2Y, and are formed at the central portion of the entire battery holder 2. This structure can smoothly insert the heat-resistant plate 13 inserted from the insertion port 15 with the pair of convex strips 17x as guiding members in a low-resistance state. In particular, by moving the front end of the heat-resistant plate 13 inserted into the insertion gap 14 from the insertion port 15 along the inclined surface 17a of the convex strip 17x, the heat-resistant plate 13 can be smoothly guided and moved on the upper surface of the convex strip 17x. In order to stably support the heat-resistant plate 13, the interval (K) between the pair of first convex portions 17A is 1 / 5 to 4 / 5 of the transverse width (W) of the heat-resistant plate 13, preferably 1 / 4 to 3 / 4.

[0070] In addition, as Figures 6 to 8As shown, the second convex portion 17B formed on the second opposing surface 16B is not formed as a convex strip extending in the longitudinal direction like the first convex portion 17A, but is formed as a rib shape with its overall length shortened. The illustrated second convex portion 17B is formed in a substantially triangular shape in a side view, and is provided with an inclined surface 17b whose protruding height gradually decreases toward the insertion port 15. The second convex portion 17B of this shape is formed in a shape with the apex of the triangle as the maximum height, and can reliably press and hold the heat-resistant plate while allowing the heat-resistant plate to slide in a state of low resistance. In particular, it has the following advantages: by moving the front end of the heat-resistant plate 13 along the inclined surface 17a provided on the first convex portion 17A and the inclined surface 17b provided on the second convex portion 17B, the heat-resistant plate 13 can be smoothly guided between the pair of first convex portions 17A and the second convex portion 17B. Figure 9 Although one second convex portion 17B is provided opposite the middle of the pair of first convex portions 17A as shown in the pressing convex portion 17, a plurality of second convex portions may also be provided. In this case, a plurality of second convex portions are located between the pair of first convex portions and are arranged at non-opposing positions with respect to the first convex portions, and are preferably arranged symmetrically left and right.

[0071] In addition, although not shown, the second convex portion may also be formed as a convex strip extending in the longitudinal direction, and an inclined surface may be provided on the insertion port side. However, in this case, the second convex portion is also preferably formed shorter than the first convex portion. In addition, the first convex portion and the second convex portion may also be formed in a rib shape with a shorter overall length. In this case, the heat-resistant plate can also be smoothly inserted by providing an inclined surface on the insertion port side.

[0072] In addition, Figure 9 The insertion gap 14 shown includes a holding gap 14A and an expanding gap 14B. The holding gap 14A is provided with the pressing convex portion 17, and the expanding gaps 14B are provided on both sides of the holding gap 14A and are formed with a wider interval than the holding gap 14A. The transverse width (S) of the holding gap 14A is narrower than the transverse width (W) of the heat-resistant plate 13, and both side portions of the heat-resistant plate 13 are arranged in the expanding gaps 14B. The above insertion gap 14 has expanding gaps 14B formed on both sides of the holding gap 14A provided with the pressing convex portion 17 and having a wider interval than the holding gap 14A. Therefore, when the elastically deformable heat-resistant plate 13 is inserted into the insertion gap 14, while deforming it in a posture bent in the transverse width direction as Figure 10 shown, both side portions of the heat-resistant plate 13 that have been elastically deformed into a bent posture are guided to the expanding gaps 14B and inserted efficiently.

[0073] The insertion gap 14 of the above structure is designed such that the minimum distance (Dm) between the first opposing surface 16A and the second opposing surface 16B is greater than the thickness (t) of the heat-resistant plate 13. Additionally, the insertion gap 14 is designed such that in a state where the heat-resistant plate 13 is not inserted, the distance (d) between the first line L1 connecting the front ends of the pair of first convex portions 17A and the front end of the second convex portion 17B is smaller than the thickness (t) of the heat-resistant plate 13. Therefore, the protruding heights (h1) of the first convex portion 17A and the protruding height (h2) of the second convex portion 17B can be designed to satisfy the above conditions. Furthermore, the first convex portion 17A and the second convex portion 17B can determine the protruding heights (h1, h2) considering their elastic deformation amounts, and the cross-sectional shape can also be changed to an optimal shape. Although the insertion gap 14 of the above structure increases the interference area between the pressing convex portion 17 and the heat-resistant plate 13 during the insertion of the heat-resistant plate 13 because the substantial distance (d) between the front ends of the pair of first convex portions 17A and the front end of the second convex portion 17B is smaller than the thickness (t) of the heat-resistant plate 13, by elastically deforming the heat-resistant plate 13 or the pressing convex portion 17, the interference portion can be absorbed and the heat-resistant plate 13 can be inserted without difficulty. Additionally, in a state where the heat-resistant plate 13 is inserted, the heat-resistant plate 13 can be elastically pressed from both sides by the first convex portion 17A and the second convex portion 17B and held in a fixed position. With the above structure, the heat-resistant plate 13 can be smoothly inserted without blocking the space between the first opposing surface 16A and the second opposing surface 16B, and the heat-resistant plate 13 cannot pass between the pair of first convex portions 17A and the second convex portion 17B, and the first convex portion 17A and the second convex portion 17B can abut against both sides of the heat-resistant plate 13 to reliably hold it.

[0074] In addition, the battery holder 2 is provided with a connection window 24 for exposing the end face electrode 11 to connect the guide plate 3 at the end face plate portion 26 facing the end face electrode 11 of the battery cell 1. The connection window 24 for the guiding convex portion electrode, i.e., the first electrode 11A, is made larger than the outer shape of the convex portion electrode and sized to allow the convex portion electrode to be inserted inside. Since the convex portion electrode is disposed inside the connection window 24 and can be welded to the guide plate 3, the level difference with the first electrode 11A exposed from the connection window 24 is reduced, and the guide plate 3 can be welded to the first electrode 11A. The connection window 24 disposed at the position facing the bottom surface of the outer can, i.e., the second electrode 11B, is opened to a size that can guide the welding portion 33 of the guide plate 3 to the second electrode 11B.

[0075] In addition, the battery holder 2 is provided with a storage area 25 for storing the circuit board 4 at the upper part. Figure 3 The shown battery holder 2 has peripheral walls protruding from the upper surface in the front, rear, left, and right directions, and recesses are provided inside the peripheral walls on the four sides as the storage area 25 for the circuit board 4. Figure 5 The battery holder 2 is provided with a gap between the bottom surface of the storage area 25 and the circuit board 4 is disposed with a gap.Figure 3 The circuit board 4 has an outer peripheral shape that fits into the inner periphery of the storage area 25 and is arranged at a fixed position, and is prevented from moving in the floating direction by engaging the circuit board 4 with claws provided on the peripheral wall. However, the battery holder 2 can also be directly fixed in the installation area of the circuit board by means of bolt fixing or the like, or a board holder for holding the circuit board can be provided separately.

[0076] (Guide plate 3)

[0077] In addition, in the illustrated battery pack 100, the guide plate 3 connects the end face electrodes 11 at both ends of a plurality of battery cells 1 held in a fixed position by the battery holder 2. The guide plate 3 is manufactured by stamping a metal plate with excellent conductivity, and is welded and fixed to the end face electrodes 11 provided on the end faces of the battery cells 1 of the battery holder 2. Figure 2 And Figure 3 The illustrated battery assembly 10 connects eight battery cells 1 in series and in parallel via the guide plate 3. In the Figure 4 battery assembly 10, four battery cells 1 arranged in two columns on the left and right and four layers arranged vertically and horizontally in the figure are connected in parallel with each other to form a parallel unit 1X, and the left and right parallel units 1X are connected in series with each other, thereby forming a battery block 1Y formed by connecting eight battery cells 1 in a 4-parallel 2-series manner. As Figure 3 shown, the battery assembly 10 serially connects two sets of parallel units 1X via an intermediate guide plate 3B on the third face 2C of the box-shaped battery holder 2, and as Figure 2 And Figure 3 shown, the output side of the parallel unit 1X that has been serially connected is connected to the output guide plate 3A on the first face 2A of the battery holder 2.

[0078] The output guide plate 3A has, on the output side of the battery block 1Y: a first output guide plate 3Aa that connects the first electrodes 11A of a plurality of battery cells 1 constituting the parallel unit 1X to each other; and a second output guide plate 3Ab that connects the second electrodes 11B to each other. Figure 3 The illustrated first output guide plate 3Aa is arranged on the right side of the first face 2A of the box-shaped battery holder 2 and is connected to the vertically adjacent first electrodes 11A. Figure 3The first output guide plate 3Aa shown is formed in a shape in which the laminated portions 31 and the welding portions 33 are alternately connected. The laminated portions 31 are laminated on the surface of the battery holder 2 and are the surfaces of the opening edges of the connection windows 24. The welding portions 33 are formed in a stepped shape one level lower than the laminated portions 31 and are connected to the first electrodes 11A disposed in the connection windows 24. The first output guide plate 3Aa is bent into a shape having a substantially rectangular wave shape in a longitudinal cross section by the alternately connected laminated portions 31 and welding portions 33. Since the first output guide plate 3Aa connects the first electrodes 11A of the four battery cells 1, four welding portions 33 are provided above and below, and the laminated portions 31 are respectively provided between and outside these welding portions 33.

[0079] The intermediate guide plate 3B includes a plate-shaped laminated portion 38. The plate-shaped laminated portion 38 is disposed on substantially the entire surface of the third surface 2C of the battery holder 2 and is connected to the end face electrodes 11 of the battery cells 1 adjacent to each other vertically, horizontally, and diagonally. The intermediate guide plate 3B connects the battery cells 1 adjacent to each other vertically in parallel via the plate-shaped laminated portion 38 on the third surface 2C of the battery holder 2, and connects the battery cells 1 adjacent to each other horizontally in series. The intermediate guide plate 3B provides the welding portions 33 welded to the end face electrodes of the battery cells 1 on the plate-shaped laminated portion 38. The welding portions 33 extend with a step from the plate-shaped laminated portion 38, and even when there is a height difference between the surface of the battery holder 2 and the surface of the end face electrode 11, the welding portions 33 are brought into surface contact with the surface of the end face electrode 11 to improve the welding reliability. In the present embodiment, since the intermediate guide plate 3B connects the battery cells 1 adjacent to each other horizontally in series, it is formed in a flat plate shape without a step at the portion of the serially connected plate-shaped laminated portion 38.

[0080] In addition, the second output guide plate 3Ab also has the welding portions 33 connected to the second electrodes 11B provided on the plate-shaped laminated portion 38 that connects the second electrodes 11B of the adjacent battery cells 1. Here, in the second output guide plate 3Ab and the intermediate guide plate 3B, the following structure is formed: the welding portions 33 connected to the second electrodes 11B are connected to the plate-shaped laminated portion 38 via the fuse portions 41 extending in an elongated shape, and the fuse portions 41 are fused in a state where an overcurrent flows, thereby reliably disconnecting the battery cells 1 from the guide plate 3.

[0081] In addition, the guide plate 3 is provided with connection terminal portions 39 for connecting to the circuit board 4 protruding upward. The connection terminal portions 39 led out from the output guide plate 3A are connected to the circuit board 4, and the output of the battery block 1Y is supplied to the circuit board 4. The connection terminal portions 39 led out from the intermediate guide plate 3B are connected to the circuit board 4, and the intermediate voltage of the battery block 1Y is supplied to the circuit board 4.

[0082] (Circuit board 4)

[0083] The circuit board 4 is mounted with electronic circuits such as a voltage detection circuit that detects the total potential and intermediate potential of the battery block 1Y in which the battery cells 1 are connected in series or in parallel, a control circuit that controls charging and discharging, and a protection circuit. The circuit board 4 is formed in a rectangular shape and is disposed in a storage area 25 provided on the upper part of the battery holder 2.

[0084] (Insulating sheet)

[0085] In addition, although not shown, the battery pack may include an insulating plate that is laminated on the surface of the guide plate 3 fixed to the battery holder 2 and covers and insulates the guide plate 3. The insulating plate is made of resin or paper, and preferably, a plate that is inexpensive, easy to handle, and has excellent heat resistance and flame retardancy against heat of emissions such as gases discharged from the battery cell 1 is used. As such an insulating plate, for example, aramid paper (Nomex [registered trademark] manufactured by DuPont) etc. can be used. The above insulating plate can be constituted by, for example, a first insulating plate, a second insulating plate, a third insulating plate, and a fourth insulating plate. The first insulating plate is disposed on the first surface 2A of the battery holder 2 having a box-shaped outer shape and covers the output guide plate 3A. The second insulating plate is disposed on the third surface 2C of the battery holder 2 and covers the intermediate guide plate 3B. The third insulating plate is disposed on the second surface 2B of the battery holder 2 and covers the connection terminal portion 39 of the first output guide plate 3Aa. The fourth insulating plate is disposed on the fourth surface 2D of the battery holder 2 and covers the connection terminal portion 39 of the second output guide plate 3Ab.

[0086] (Exterior sheet 7)

[0087] The battery assembly 10 in which an insulating plate is disposed on the surface of the guide plate 3 and the surface of the circuit board 4 is covered with the insulating member 6 is covered with the exterior sheet 7 as Figure 1 shown. As Figure 2 shown, the exterior sheet 7 is a heat-shrinkable bag or tube, and is covered by heat-shrinking it in a state where the battery assembly 10 is accommodated inside. In such an exterior sheet 7, preferably, a resin such as PET with excellent insulation and stability can be used. In particular, a shrink tube made of PET resin is inexpensive as a heat shrink tube, and thus is preferred. The exterior sheet 7 can be melted by emissions such as high-temperature gases discharged from the safety valve of the first electrode 11A of the battery cell 1, and the emissions can be quickly discharged to the outside of the battery pack 100.

[0088] (Lead wire 18, connector 19)

[0089] In addition, Figures 1 to 5The battery pack 100 shown connects a plurality of lead wires 18 to the circuit board 4 and leads them out from the battery assembly 10 to the outside. The lead wires 18 are composed of positive and negative power lines and signal lines, and are directly connected to the connector of the device on which the battery pack 100 is set. One end of the plurality of lead wires 18 is connected to the circuit board 4, and a connector 19 is connected to the other end.

[0090] The above battery pack 100 is assembled through the following processes.

[0091] (1) The battery cells 1 are arranged at the fixed positions of the first divided bracket 2X and the second divided bracket 2Y and connected. The first divided bracket 2X and the second divided bracket 2Y are connected in a state where the battery cells 1 are inserted into the respective battery storage portions 21. The first divided bracket 2X and the second divided bracket 2Y are connected at the fixed positions via the built-in battery cells 1, and in addition, they are connected by a locking structure provided at the opposed positions of the first divided bracket 2X and the second divided bracket 2Y so as not to come off. Further, in a state where the first divided bracket 2X and the second divided bracket 2Y are already connected, the first insertion gap 14X of the first divided bracket 2X and the second insertion gap 14Y of the second divided bracket 2Y are arranged linearly to form the insertion gap 14 for the heat-resistant plate 13.

[0092] (2) The heat-resistant plate 13 is arranged at the fixed position of the insertion gap 14 formed by the mutually connected first divided bracket 2X and second divided bracket 2Y. The heat-resistant plate 13 is inserted from the insertion port 15, which is one open end of the first insertion gap 14X of the first divided bracket 2X, into the insertion gap 14 with respect to the partition wall 22 provided on the connected first divided bracket 2X and second divided bracket 2Y, and is arranged at the fixed position inside the partition wall 22.

[0093] At this time, the heat-resistant plate 13 is inserted into the insertion gap 14 in a state where it is elastically deformed into a posture bent in the width direction (refer to Figure 10 ) or is inserted in a state where the pressing convex portion 17 protruding from the opposed surface 16 is elastically deformed in the insertion gap 14, and is elastically pressed by the elastically deformed heat-resistant plate 13 or pressing convex portion 17, so as to be held at the fixed position in the insertion gap 14.

[0094] (3) The guide plate 3 is connected to the end face electrodes 11 of the battery cells 1 exposed from both end faces of the battery bracket 2 to electrically connect all the battery cells 1 housed in the battery bracket 2. The guide plate 3 is electrically connected and fixed to the end face electrodes 11 of the battery cells 1 by welding.

[0095] (4) The circuit board 4 is connected to the fixed position of the battery bracket 2. Figure 3The battery holder 2 shown has a storage area 25 on its upper surface, and a circuit board 4 is disposed at a fixed position in the storage area 25.

[0096] (5) Electrically connect the connection terminal portion 39 led out from the guide plate 3 to the circuit board 4 already connected to the battery holder 2. The connection terminal portion 39 is disposed at a fixed position of the circuit board 4, and is electrically connected to the circuit board 4 by spot welding or the like and physically connected. Lead out the lead wire 18 already connected to the circuit board 4 to the outside, and cover the upper surface of the battery holder 2 with an insulating member 6 for insulation. In addition, cover the surface of the guide plate 3 disposed on the surface of the battery holder 2 with an insulating sheet (not shown) for insulation. In the above state, as Figure 2 shown, the battery assembly 10 is manufactured.

[0097] (6) Cover the battery assembly 10 with an outer packaging sheet 7. As Figure 2 shown, the outer packaging sheet 7 is a heat-shrinkable bag or tube, and is covered by heat-shrinking it in a state where the battery assembly 10 is accommodated inside.

[0098] The above battery pack 100 can be built into the main body of an electrical device such as a speaker and used as a power source. The battery pack 100 supplies power to the main body device via the lead wire 18 led out to the outside, or supplies power from the main body device to charge the built-in battery cell 1. The lead wire 18 led out from the battery pack 100 is connected to the connector on the main body side via the output connector 19 connected to the front end and is supplied with power.

[0099] Industrial Applicability

[0100] The battery pack of the present invention can be ideally used as a power source for electrical devices such as wireless speakers, electric cleaners, or electric tools. In addition, it can also be appropriately used for applications such as power supply devices for moving bodies such as auxiliary bicycles or electric forklifts.

[0101] Description of Reference Numerals

[0102] 100: Battery pack

[0103] 1: Battery cell

[0104] 1X: Parallel unit

[0105] 1Y: Battery block

[0106] 2: Battery holder

[0107] 2X: First divided holder

[0108] 2Y: Second divided holder

[0109] 2A: First surface

[0110] 2B: Second side

[0111] 2C: Third side

[0112] 2D: Fourth side

[0113] 3: Guide plate

[0114] 3A: Output guide plate

[0115] 3Aa: First output guide plate

[0116] 3Ab: Second output guide plate

[0117] 3B: Intermediate guide plate

[0118] 4: Circuit board

[0119] 6: Insulating member

[0120] 7: Exterior sheet

[0121] 10: Battery assembly

[0122] 11: End face electrode

[0123] 11A: First electrode

[0124] 11B: Second electrode

[0125] 13: Heat-resistant plate

[0126] 14: Insertion gap

[0127] 14X: First insertion gap

[0128] 14Y: Second insertion gap

[0129] 14A: Holding gap

[0130] 14B: Expansion gap

[0131] 15: Insertion port

[0132] 16: Opposing surface

[0133] 16A: First opposing surface

[0134] 16B: Second opposing surface

[0135] 17: Pressing convex part

[0136] 17A: First convex part

[0137] 17a: Inclined surface

[0138] 17x: Rib

[0139] 17B: Second convex part

[0140] 17b: Inclined surface

[0141] 18: Lead-out wire

[0142] 19: Connector

[0143] 20: Holding cylinder part

[0144] 21: Battery storage part

[0145] 22: Partition wall

[0146] 23: Holding wall part

[0147] 24: Connection window

[0148] 25: Storage area

[0149] 26: End panel part

[0150] 27: Locking hook

[0151] 28: Locking part

[0152] 31: Laminated part

[0153] 33: Welding part

[0154] 38: Plate-like laminated part

[0155] 39: Connection terminal part

[0156] 41: Fusing part

[0157] 901: Battery cell

[0158] 902: Battery holder

[0159] 913: Sheet material

[0160] 914: Insertion gap

[0161] 916: Opposing surface

[0162] 917: Rib

[0163] 922: Partition wall

[0164] 923: Holding wall part.

Claims

1. A battery pack, comprising: a plurality of battery cells; a battery holder that arranges the plurality of battery cells in a parallel posture and has partition walls disposed between the mutually adjacent battery cells; and a heat-resistant plate that is inserted inside the partition wall of the battery holder and is disposed between the adjacent battery cells, the partition wall has a pair of holding wall portions respectively opposed to the adjacent battery cells, and an insertion gap for arranging the heat-resistant plate at a fixed position is formed between the pair of holding wall portions, the pair of holding wall portions respectively form pressing convex portions for pressing the heat-resistant plate on the opposed surfaces opposed to the heat-resistant plate disposed in the insertion gap, in a cross section of the partition wall, the pressing convex portion includes: a pair of first convex portions that are separately formed on one opposed surface in the width direction; and a second convex portion that is located between the pair of first convex portions and is formed on the other opposed surface, elastically deforming either the heat-resistant plate inserted into the insertion gap or the pressing convex portion, and pressing the heat-resistant plate from both sides by the pair of first convex portions and the second convex portion, thereby holding the heat-resistant plate at a fixed position in the insertion gap.

2. The battery pack according to claim 1, wherein the battery holder is provided with the insertion gap so as to penetrate the partition wall in the length direction of the battery cell, the pressing convex portion is provided on the opposed surface so as to be located at the central portion in the length direction of the insertion gap, and one open end of the insertion gap is used as an insertion port for inserting the heat-resistant plate.

3. The battery pack according to claim 2, wherein the battery holder is divided into two parts in the middle of the length direction of the battery cell, one of the divided holders has the insertion port at one end of the insertion gap and the pressing convex portion at the other end.

4. The battery pack according to claim 1, wherein the insertion gap includes a holding gap and an expansion gap, the holding gap is provided with the pressing convex portion, the expansion gaps are provided on both sides of the holding gap and are formed to have a width wider than that of the holding gap, the transverse width of the holding gap is narrower than the transverse width of the heat-resistant plate, and both side portions of the heat-resistant plate are arranged in the expansion gap.

5. The battery pack according to claim 2 or 3, wherein the pair of first convex portions and the second convex portion have inclined surfaces with a gradually decreasing protruding height toward the insertion port.

6. The battery pack according to claim 2 or 3, wherein the pair of first convex portions are convex strips extending in the length direction of the insertion gap, the convex strip has an inclined surface with a gradually decreasing protruding height toward the insertion port.

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