Power supply device

Abstract

The present invention reduces the size but maintains the safety of a power supply device in which end surfaces of secondary battery cells are opposite each other.　A power supply device (100) that comprises: a plurality of battery cells (1) that comprise a discharge valve (3) that discharges gas when internal pressure rises; a plurality of battery blocks (10) that hold the plurality of battery cells (1) such that outer cans (2) are parallel and end surfaces of the outer cans (2) are in the same plane, the battery blocks (10) being arranged such that block surfaces of neighboring battery blocks (10) are opposite each other across an insulation space (30); shielding plates (40) that are arranged in the insulation spaces (30); and support members (50) that are provided further to the inside than outer peripheral parts of opposite block surfaces of the battery blocks (10) and support the shielding plates (40). As supported by the support members (50), the shielding plates (40) have outer peripheral parts that are displaceable free ends (42) relative to the support members (50) as base points.

Description

[Technical Field]

[0001] The present invention relates to a power supply device. [Background Art]

[0002] Power supply devices such as battery packs are used as power sources for electrically assisted bicycles, electric motorcycles, power tools, electric cleaners, and the like. In the power supply device, a large number of secondary battery cells are arranged and connected in series or parallel to achieve higher output and higher capacity. For example, a power supply device 90 of Patent Document 1 shown in FIG. 12 has battery units 92 each having a plurality of secondary battery cells 91 arranged in parallel with each other connected in a posture where end faces of the secondary battery cells 91 face each other, and is housed in a housing.

[0003] Each secondary battery cell 91 is provided with a safety valve, which detects when the pressure inside the outer can becomes high and opens to discharge high-pressure, high-temperature gas inside the outer can to the outside of the cell. Since the power supply device 90 of FIG. 12 is arranged in a posture where the end faces of the secondary battery cells 91 face each other, when high-temperature gas is ejected from any one of the secondary battery cells 91, it is conceivable that the high-temperature gas will irradiate another secondary battery cell 91 adjacent to this secondary battery cell 91 and arranged with its end face facing, causing damage thereto.

[0004] Therefore, in the power supply device 90 of FIG. 12, a heat-resistant sheet 93 is arranged between opposing battery units 92, and exhaust chambers 94, 94 for exhausting ejected gas are provided on both sides of the heat-resistant sheet 93. In order to hold the heat-resistant sheet 93, outer peripheral frame portions 95, 95 are formed. The outer peripheral frame portions 95, 95 are formed in a shape along the outer peripheral portion of the heat-resistant sheet 93. By arranging the outer peripheral frame portions 95, 95 on both sides of the heat-resistant sheet 93 and between the opposing battery units 92, the outer peripheral portion of the heat-resistant sheet 93 is supported, and the heat-resistant sheet 93 is held between the battery units 92.

[0005] In the power supply unit 90 shown in Figure 12, the number of secondary battery cells 91 can be increased by stacking them in the vertical direction d1 of Figure 12. On the other hand, in some cases, such as when used in an electric assist bicycle, a long, narrow housing is required due to constraints on the location where the power supply unit is placed. In this case, the arrangement is such that the number of stacked units in the d1 direction of Figure 12 is reduced for each battery unit, and multiple battery units 92 are arranged in a direction d2 perpendicular to this. In such a configuration, it is necessary to provide heat-resistant sheets 93 and exhaust chambers 94, 94 at the opposing interfaces of each battery unit to ensure a gas exhaust passage between each battery unit.

[0006] However, as the number of battery units connected in the d2 direction increased, heat-resistant sheets and exhaust chambers provided on both sides became necessary at each interface between the battery units, which could cumulatively increase the size of the housing in the d2 direction. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] International Publication No. 2019 / 065169 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] One of the objectives of the present invention is to provide a power supply device that is miniaturized while ensuring safety, in a power supply device in which secondary battery cells are arranged in a position where their end faces face each other. [Means for solving the problem]

[0009] A power supply device according to one aspect of the present invention comprises: a plurality of battery cells, each formed in a cylindrical shape with an outer casing extended in one direction, and having a discharge valve for discharging gas when the internal pressure rises on one end face of the cylindrical shape; a plurality of battery blocks that each hold the plurality of battery cells in a parallel position with the outer casings and the end faces of the outer casings being on the same plane; a shielding plate placed in an insulating space, such that the block faces of the plurality of battery blocks, each facing each other with an insulating space between them, and the block faces of the adjacent battery blocks being separated from each other with an insulating space between them; and a support member that supports the shielding plate, provided inside the outer periphery of each of the opposing block faces of the plurality of battery blocks, wherein the shielding plate supported by the support member has a free end that can be displaced around the support member. [Effects of the Invention]

[0010] With the above configuration, the shielding plate can be displaced with a free end. Therefore, even if the discharge valve opens in any of the battery cells and gas is ejected, the high-temperature, high-pressure gas will press against the shielding plate and displace it towards the opposing battery block within the insulating space, resulting in a wide flow path for the ejected gas to be discharged. As a result, it becomes possible for both battery blocks to share a single insulating space, without having to pre-provide large insulating spaces on both sides of the shielding plate as in conventional designs, thus enabling miniaturization of the entire power supply unit. [Brief explanation of the drawing]

[0011] [Figure 1] This is a perspective view showing a power supply device according to one embodiment of the present invention. [Figure 2] Figure 1 is an exploded perspective view of the power supply unit with its outer casing removed, including an enlarged side view of the main components. [Figure 3] Figure 2 is a disassembled perspective view of the battery assembly. [Figure 4] Figure 2 is a cross-sectional view of the battery assembly along the IV-IV line. [Figure 5] This is a cross-sectional view showing the state in which gas is being ejected from the battery cell in Figure 4. [Figure 6] It is a cross-sectional view showing a state where gas has ejected from another battery cell in FIG. 4 [Figure 7] It is a partial cross-sectional view of the power supply device according to Embodiment 2 [Figure 8] It is a cross-sectional view showing a state where gas has ejected from the battery cell in FIG. 7 [Figure 9] It is a partial cross-sectional view of a power supply device according to a modified example [Figure 10] It is a partial cross-sectional view of the power supply device according to Embodiment 3 [Figure 11] It is a cross-sectional view showing a state where gas has ejected from the battery cell in FIG. 10 [Figure 12] It is a cross-sectional view showing a conventional power supply device [Figure 13] It is a perspective view showing another conventional power supply device [Figure 14] It is a cross-sectional view taken along line XIV-XIV of the power supply device in FIG. 13 MODES FOR CARRYING OUT THE INVENTION

[0012] A power supply device according to one aspect of the present invention may be configured as follows in addition to the above configuration. In the power supply device, the support member may include: a first support member provided on one block surface of the mutually opposing battery blocks; and a second support member provided at a position corresponding to the first support member on the other block surface of the battery block, and connected to the first support member via the shielding plate

[0013] In the power supply device described above, the shielding plate is formed with a shielding plate opening at a position corresponding to the support member, and the support member can be inserted through the shielding plate opening

[0014] In the power supply device described above, a plurality of the support members may be provided on each end face of the battery block

[0015] In the power supply device described above, the support member is provided at a central portion of each end face of the battery block, and the shielding plate is movable in the rotational direction with the support member serving as a fulcrum. With the above configuration, the end of the shielding plate on the side closer to the battery cell that has ejected gas moves in a direction away from the battery cell, thereby forming a flow path for gas discharge. On the other hand, the opposite end of the shielding plate moves toward the battery cell that has ejected gas so as to close the insulating space. As a result, a flow path for gas discharge can be formed on the side closer to the battery cell that has ejected gas, enabling the ejected gas to be discharged through the shortest path.

[0016] The power supply device may further comprise a plurality of auxiliary support portions that are melted by heat and provided between mutually opposing block surfaces of the plurality of battery blocks. With the above configuration, the shielding plate can be stably held in the insulating space by the support member and the auxiliary support portions. Meanwhile, when high-temperature and high-pressure gas is ejected from any secondary battery cell in an emergency, the auxiliary support portions are melted by heat, which does not hinder the displacement of the shielding plate or the discharge of gas, thereby realizing smooth gas discharge.

[0017] In the power supply device described above, the shielding plate can be made of carbon fiber, silica fiber, glass fiber, or a flexible material obtained by impregnating any of these fibers with a resin. With the above configuration, the flexible shielding plate can be deflected when gas is ejected, allowing the flow path for gas discharge to be easily formed.

[0018] Furthermore, the shielding plate can also be made of a metal plate, a metal plate with insulating materials bonded to the front and back surfaces, a metal plate with insulation treatment performed on the front and back surfaces, a mica sheet, or a flame-retardant fiber. With the above configuration, the rigidity of the shielding plate can be increased.

[0019] The embodiments of the present invention will be described below with reference to the drawings. However, the embodiments shown below are illustrative of configurations for realizing the technical concept of the present invention, and the present invention is not limited to these. Furthermore, the members shown in the claims are not limited to the members of the embodiments. In particular, the dimensions, materials, shapes, relative arrangements, etc. of the constituent members described in the embodiments are merely illustrative examples and are not intended to limit the scope of the present invention to those described unless otherwise specifically stated. Note that the size and positional relationships of the members shown in each drawing may be exaggerated to clarify the explanation. Furthermore, in the following description, the same name and reference numerals indicate the same or similar members, and detailed explanations are omitted as appropriate. Furthermore, each element constituting the present invention may be configured such that multiple elements are made of the same material, with one material serving multiple elements, or conversely, the function of one material can be shared among multiple materials. In addition, some of the contents described in some embodiments may be applicable to other embodiments.

[0020] The power supply devices described below primarily illustrate applications as power sources for electric vehicles such as electric bicycles, electric scooters, electric carts, and electric automobiles that run solely on their motors. However, the power supply devices of the present invention may also be used in hybrid vehicles that run on both engines and motors, or in applications requiring high output other than electric vehicles, such as household or factory energy storage devices. [Embodiment 1]

[0021] Figures 1 to 6 show a power supply device according to Embodiment 1. In these figures, Figure 1 is a perspective view showing a power supply device according to one embodiment of the present invention, Figure 2 is an exploded perspective view with an enlarged side view of the main part with the outer casing of the power supply device of Figure 1 removed, Figure 3 is an exploded perspective view of the battery assembly of Figure 2, Figure 4 is a cross-sectional view of the battery assembly of Figure 2 along line IV-IV, Figure 5 is a cross-sectional view showing the state in which gas is ejected from the battery cell of Figure 4, and Figure 6 is a cross-sectional view showing the state in which gas is ejected from another battery cell of Figure 4. (Power supply 100)

[0022] The power supply unit 100 shown in these figures comprises a plurality of generally cylindrical battery cells 1, a plurality of battery blocks 10 (10-1 to 10-3 in Figure 1, etc.) that hold these battery cells 1, a battery assembly 60 formed by connecting these plurality of battery blocks 10, and an outer case 20 that houses the battery assembly 60. Here, we will explain the general outline of the power supply unit 100, and the details of each component will be described later.

[0023] In the power supply unit 100 shown in Figure 2, multiple battery blocks 10-1 to 10-3 are arranged and connected in the axial direction of the cylindrical battery cell 1. For example, the first block surface 11 of battery block 10-1 is spaced apart from the second block surface 12 of the adjacent battery block 10-2, with an insulating space 30 separating them.

[0024] The power supply unit 100 further includes a shielding plate 40 positioned in the insulating space 30 and a support member 50 that supports the shielding plate 40. The support member 50 is provided inside the outer periphery of each of the opposing first block surfaces 11 and second block surfaces 12 of the plurality of battery blocks 10. The shielding plate 40, supported by the support member 50 provided inside the block surfaces in this way, has a free end 42 at its outer periphery that can be displaced with respect to the support member 50.

[0025] Here, "free end 42" refers to the outer periphery of the shielding plate 40 and its vicinity, which are not supported by support members or the like, and are therefore displaceable, that is, the outer periphery of the shielding plate 40 and its vicinity, which can be deformed or moved.

[0026] By making the outer periphery of the shielding plate 40 a free end 42, as shown in Figure 5, if the discharge valve 3 opens in the battery cell 1L of the battery block 10-1 and gas is ejected, the shielding plate 40 is pressed by the high-temperature, high-pressure gas, causing the outer periphery of the shielding plate 40, which is the free end 42, to be displaced towards the battery block 10-2 side within the insulating space 30. As a result, a flow path B for discharging the ejected gas is formed on the battery block 10-1 side from which the gas was ejected. At this time, the battery block 10-2 side is closed by the shielding plate 40. As a result, by providing an insulating space 30 large enough to form one flow path B on the outer periphery of the interface between battery blocks 10-1 and 10-2, it is possible to facilitate gas discharge.

[0027] Similarly, if gas is ejected from the battery cell 1R of battery block 10-2, the free end 42 of the shielding plate 40 is displaced toward the battery block 10-1 side, as shown in Figure 6, to form a flow path B toward the battery block 10-2 side. In this way, it is possible to share one insulating space 30 between the battery blocks 10-1 and 10-2 on both sides, without having to provide two wide exhaust chambers 94 on both sides of the heat-resistant sheet 93 in advance, as in the conventional power supply device 90 shown in Figure 12.

[0028] As a result, in this embodiment in which a power supply device 100 is constructed by arranging multiple battery blocks 10 in the axial direction of the battery cell 1, miniaturization in the arrangement direction of the battery blocks 10 is achieved. Because such a power supply device 100 has an elongated shape, it can be suitably applied to bicycles for various purposes such as electric assist bicycles and sports type bicycles, and it is easy to install, small and inconspicuous, which can improve the overall appearance of the bicycle. (Battery cell 1)

[0029] As shown in Figure 4, the multiple battery cells 1 that supply power to the power supply unit 100 are formed in a generally cylindrical shape with the outer casing 2 extended in one direction. Each battery cell 1 is equipped with a discharge valve 3 on one end face of the cylindrical shape to discharge gas when the internal pressure rises. Each battery cell 1 is further provided with end electrodes 4 at both ends. This battery cell 1 has an opening of a metal outer casing 2 made of aluminum or the like that is airtightly sealed with a sealing plate, with a protruding electrode on the sealing plate to serve as the first end electrode 4a, and the bottom surface of the outer casing serving as the second end electrode 4b. The discharge port of the discharge valve 3 is provided on the side of the protruding electrode or on the bottom surface of the outer casing.

[0030] For example, a cylindrical lithium-ion battery can be used for the battery cell 1. Lithium-ion batteries have a large capacity relative to their size and weight, which can increase the total capacity of the power supply unit. However, the power supply unit of the present invention is not limited to lithium-ion batteries for the battery cell. Other rechargeable secondary batteries can be used for the battery cell. Also, although the power supply unit 100 in Figure 4 etc. uses a cylindrical battery for the battery cell 1, a prismatic battery can also be used for the battery cell. Lead plates 5 are welded to the end electrodes 4 at both ends of each battery cell 1, and adjacent battery cells 1 are connected in series or parallel. The type and number of such battery cells 1 can be adjusted as appropriate according to the required amount of power. For example, in this embodiment, 10 battery cells of about 5 A / h are used. (Battery block 10)

[0031] The battery block 10 holds these multiple battery cells 1 in a parallel orientation. Multiple of these battery blocks 10 are arranged in the axial direction of the battery cells 1 to form a battery assembly 60, which will be described later. (Battery holder 13)

[0032] Each battery block 10 is equipped with a generally cylindrical battery holder 13 that holds multiple battery cells 1. The battery holder 13 is made by molding an insulating material such as plastic. The battery holder 13 holds the outer casings 2 of the multiple battery cells 1 in a position parallel to each other, with the end faces of the outer casings 2 being on the same plane.

[0033] The battery holder 13 has an insertion section 13a into which the battery cell 1 is inserted and positioned. In the power supply device 100 shown in Figure 4, the battery cell 1 is a cylindrical battery, so the insertion section 13a is cylindrical.

[0034] The battery holder 13 also comprises a first block surface 11 and a second block surface 12 located on both end faces of the outer casing 2, which are aligned in the same plane, thereby closing off both ends of the battery holder 13. Openings 14 are formed in these first block surface 11 and second block surface 12 to expose the battery ends. The openings 14 expose the ends of the battery cell 1 inserted into the insertion portion 13a to the outside. Lead plates 5 are welded and fixed to the end faces of the battery cell 1 exposed through the openings 14 as end electrodes 4. Note that the lead plates are omitted in Figures 1 to 3 for illustrative purposes. (Battery assembly 60)

[0035] The battery assembly 60 is formed by arranging and connecting multiple such battery blocks 10 in the axial direction of the battery cell 1. As shown in Figure 1, in this embodiment, three battery blocks 10-1 to 10-3 are connected, but the number of battery blocks 10 can be adjusted as appropriate according to the required power. This battery assembly 60 is housed in an outer case 20. The outer case 20 can further house a circuit board on which charge / discharge circuits and protection circuits for controlling the charging and discharging of the battery cell 1 are mounted. (Insulation space 30)

[0036] The insulating space 30 is formed to separate adjacent battery blocks 10 of the battery assembly 60. For example, as shown in Figure 5, the first block surface 11 of battery block 10-1 is separated from the second block surface 12 of the adjacent battery block 10-2, with the insulating space 30 separating them. At this time, the width of the insulating space 30, in other words, the separation distance A between battery blocks 10-1 and 10-2, is approximately the sum of the width of one flow path B and the thickness C of the shielding plate 40, which will be described later. The width of the flow path B can be adjusted as appropriate depending on the type of battery, and in this embodiment, it is set to about 3 to 4 mm.

[0037] In a battery assembly 60 where the end faces of battery cells 1 are positioned on both sides of an insulating space 30, if, for example, the discharge valve 3 of any battery cell 1 in battery block 10-1 opens, the high-temperature ejected gas discharged from the outlet is sprayed toward the second block surface 12 of the opposing battery block 10-2. The high-temperature ejected gas sprayed toward the opposing surface of the battery cell 1 in the opposing position can cause thermal runaway of the battery cell 1. (Shielding plate 40)

[0038] Therefore, in the power supply unit 100 shown in Figures 3 to 6, a shielding plate 40 is placed approximately in the middle of the insulating space 30. The shielding plate 40 is intended to prevent gas from being sprayed onto the opposing battery block 10 in the event that gas is discharged from any of the battery cells 1. The size of the shielding plate 40 can be any size as long as it prevents gas from being sprayed onto the opposing battery block 10. In this embodiment, the size and shape are approximately the same as the first block surface 11 and the second block surface 12 of the battery block 10.

[0039] The shielding plate 40 can be made of a heat-resistant material that has a melting point, i.e., a heat resistance temperature, that prevents it from melting due to the ejected gas discharged from the discharge valve 3. Furthermore, the shielding plate 40 can also be flexible. For example, in Embodiment 1, the shielding plate 40 can be made from carbon fiber, silica fiber, glass fiber, or a flexible material made by impregnating these with resin. The flexibility of the shielding plate 40 allows the high-temperature, high-pressure gas pressure during gas ejection to deform the shielding plate 40, easily forming the gas discharge channel B described later.

[0040] The shielding plate 40 in Figure 4 is positioned parallel to the first block surface 11 and the second block surface 12 of the adjacent battery block. Flow channels B', approximately half the width of flow channel B, are formed on both sides of the shielding plate 40. This makes the distance A between battery blocks 10-1 and 10-2 approximately the sum of the widths of the two flow channels B' (i.e., flow channel B) and the thickness C of the shielding plate 40. By positioning the shielding plate 40 in this way, if gas is ejected from the battery cell 1 of one battery block 10, the periphery of the shielding plate 40 deforms toward the other battery block 10, forming the flow channels B shown in Figures 5 and 6. (Support member 50)

[0041] The support members 50 are members that support the shielding plate 40. Figures 3 and 4 show one embodiment of the support members 50. As shown in these figures, the support members 50 are provided inside the outer periphery of the first block surface 11 and the second block surface 12 of the multiple battery blocks 10 that are opposite to each other. The number of support members 50 can also be adjusted as appropriate to match the size of the shielding plate 40. For example, in Embodiment 1, four first support members 51 are provided on the first block surface 11 of the battery block 10, two in the vertical direction and two in the horizontal direction. Similarly, four second support members 52 are provided on the second block surface 12 at positions corresponding to the first support members 51.

[0042] The shapes of the first support member 51 and the second support member 52 can be any shape as long as they can be connected to each other. In this embodiment, the first support member 51 is convex, and the second support member 52 is concave, which can be connected to the first support member 51. The shielding plate 40 is supported by connecting these first support member 51 and second support member 52 via the shielding plate 40. At this time, a shielding plate opening 41 can also be formed in the shielding plate 40 at a position corresponding to the first support member 51 and the second support member 52. The size of the shielding plate opening 41 is such that, for example, the tip 51a of the first support member 51 in Figure 3 can pass through it. The tip 51a of the first support member 51 that has passed through this shielding plate opening 41 is inserted into the second support member 52 and connected, and the shielding plate 40 is fixed and supported around the central part of the shielding plate 40 by sandwiching it from both sides.

[0043] However, the support members and shielding plates of this embodiment are not limited to the above configuration. For example, it goes without saying that the first support member can be concave and the second support member can be convex. Furthermore, it is also possible to omit the shielding plate opening 41 in the shielding plate 40, make the first and second support members convex, and support the shielding plate 40 by sandwiching it from both sides.

[0044] In this way, by providing the support member 50 inward from the outer periphery of the first block surface 11 and the second block surface 12, the outer periphery of the shielding plate 40 and its vicinity are not supported, but the area around the central part of the shielding plate 40 is supported. In other words, the peripheral part of the shielding plate 40 and its vicinity are made into free ends 42. As a result, as shown in Figure 5, if the discharge valve 3 is opened in the battery cell 1L of the battery block 10-1 and gas is ejected, the high-temperature, high-pressure gas will press against the shielding plate 40 which has free ends 42, causing the free ends 42 of the shielding plate 40 to deform towards the opposing battery block 10-2 within the insulating space 30. As a result, a flow path B for discharging the ejected gas is secured.

[0045] On the other hand, in the conventional power supply device 900, which connects two battery blocks 910, 910 facing each other as shown in Figures 13 and 14, the outer periphery of the heat-resistant sheet 920 is fixed. In this case, the heat-resistant sheet 920 is fixed by being sandwiched from both sides by protrusions that protrude from the periphery of the block surface of the battery block. In such a power supply device 900, the periphery of the interface between the opposing battery blocks 910 is closed, so a gas outlet 940 is provided in part. However, because the outer periphery of the heat-resistant sheet 920 is fixed, the periphery of the heat-resistant sheet 920 cannot be displaced to form path B as in Embodiment 1. Therefore, it is necessary to form exhaust chambers 930, 930 on both sides of the heat-resistant sheet 920, which will serve as path B for gas discharge.

[0046] Specifically, as shown in Figure 14, a heat-resistant sheet 920 is placed in the middle portion of the block surface of the opposing battery block 910. Since the periphery of this heat-resistant sheet 920 is fixed, exhaust chambers 930, 930 are formed on both sides of the heat-resistant sheet 920, forming two gas discharge channels B.

[0047] If we assume that the heat-resistant sheet 920 has the same thickness C as the shielding plate 40, then the distance A'' between the block surfaces of the battery block 910 will be approximately the width of the two flow channels B plus the thickness C of the heat-resistant sheet 920. In other words, because two flow channels B are formed, the distance A'' between the block surfaces of the battery block 910 becomes wider than the distance A in the power supply device 100 of Embodiment 1 by the width of one flow channel B.

[0048] In contrast, in the power supply unit 100 of Embodiment 1, the outer periphery of the shielding plate 40 is a displaceable free end 42. Therefore, even if gas is ejected from the battery cell 1 of either battery block 10, the outer periphery of the shielding plate 40 deforms toward the other battery block 10, forming a gas exhaust path B. As a result, it is possible for both battery blocks 10 to share one insulating space 30 without having to provide two exhaust chambers 930, 930 on both sides of the heat-resistant sheet 920 as in the conventional design, thus enabling miniaturization in the arrangement direction of the battery blocks 10. As a result, a power supply unit that is longer and smaller than conventional designs can be realized while ensuring safety, and can be suitably applied to various types of bicycles and the like. [Embodiment 2]

[0049] Embodiment 1 describes an example in which carbon fiber, silica fiber, glass fiber, or a flexible material obtained by impregnating these with resin is used for the shielding plate 40, and the inner side of the outer periphery of the shielding plate 40 is fixed with a support member 50. However, the power supply device of this disclosure is not limited to the above embodiment. Figure 7 shows a cross-sectional view of a part of the power supply device 100B according to Embodiment 2. In Figure 7, the same reference numerals are used for the same components as those described in Embodiment 1 above, and detailed descriptions are omitted as appropriate.

[0050] This power supply unit 100B is equipped with a shielding plate 40B that has a certain degree of rigidity, instead of the flexible shielding plate 40 of Embodiment 1. Any known heat-resistant material can be appropriately used to make up the shielding plate 40B. Alternatively, a metal plate, a metal plate with insulating material laminated to both sides, a metal plate with insulating treatment applied to both sides, a mica sheet, or flame-retardant fiber can be used. By increasing the rigidity of the shielding plate 40B in this way, the durability of the power supply unit 100B is enhanced.

[0051] Because the shielding plate 40B has high rigidity, instead of deforming the outer periphery of the shielding plate 40B to form the gas discharge channel B, the entire shielding plate 40B is moved within the insulating space 30 to form the channel B. In other words, instead of deforming a part of the shielding plate 40B, the shielding plate 40B itself is moved to achieve displacement of the outer periphery of the shielding plate, thereby ensuring a wide gas discharge channel.

[0052] Specifically, instead of fixing the inner side of the outer periphery of the shielding plate 40 with the support member 50 as in Embodiment 1, the shielding plate 40B is made movable in the direction of arrow d3 (left-right direction in Figure 7) on the outer surface of the support member 50B, which connects the first support member 51B and the second support member 52B, as shown in Figure 7.

[0053] Furthermore, if gas is ejected from the battery cell 1L of battery block 10-1, the shielding plate 40B in Figure 8 will move toward battery block 10-2, forming a gas discharge channel B toward battery block 10-1. (Auxiliary support part 70)

[0054] The power supply unit 100B may further be equipped with a plurality of auxiliary support parts 70 that melt with heat. By providing the auxiliary support parts 70, it is possible to restrict the movement of the shielding plate 40B, which is movable within the insulating space 30, during normal operation. This prevents the shielding plate 40B from moving due to external vibrations during normal operation and coming into contact with the left and right block surfaces. As a result, it is possible to prevent the generation of noise due to contact between the shielding plate 40B and the block surfaces.

[0055] In the power supply unit 100 shown in Figure 7, for example, auxiliary support parts 70 are provided between the first block surface 11 of the battery block 10-1 and the second block surface 12 of the battery block 10-2, and around the support member 50B. The auxiliary support parts 70 can be made of, for example, resin.

[0056] With this configuration, the shielding plate 40B can be stably held within the insulating space 30 by the support member 50B and the auxiliary support part 70. On the other hand, if high-temperature, high-pressure gas is ejected from any of the secondary battery cells 1, the auxiliary support part 70 is designed to melt due to the heat, thereby enabling smooth gas discharge without hindering the movement of the shielding plate 40B or the discharge of the gas.

[0057] According to the power supply device of Embodiment 2 described above, by moving the entire shielding plate 40B instead of just a part of it when gas is discharged, a wide gas discharge passage can be secured throughout. In other words, the situation in which the gas discharge passage is partially narrowed can be avoided, resulting in the advantage of being able to discharge gas more smoothly.

[0058] Furthermore, in the power supply device according to Embodiment 2 described above, an example was described in which the auxiliary support portion 70 that melts with heat is provided around the support member 50B, but the present invention is not limited to this configuration for the position in which the auxiliary support portion 70 is provided. For example, an auxiliary support may be provided separately at a position different from the support member. For example, as in the modified power supply device shown in Figure 9, the auxiliary support portion 70B can also be arranged between the support members 50B.

[0059] With this configuration, the auxiliary support portion 70B can be made thicker, thereby securing a wider contact area for holding the shielding plate 40B and enabling stable holding of the shielding plate 40B. Furthermore, the auxiliary support portion 70B may be provided in multiple locations. This increases the number of points where the auxiliary support portion 70B holds the shielding plate 40B, further stably suppressing vibration and rattle of the shielding plate 40B. Additionally, an auxiliary support portion 70B may be added in addition to the auxiliary support portion 70 shown in Figure 7. In any case, the auxiliary support portion 70B is made of a material that melts instantly when gas is discharged due to the high temperature and pressure of the gas, so as not to obstruct gas discharge during gas release.

[0060] Furthermore, in the power supply device according to Embodiment 2, a shielding plate opening 41 is made in the shielding plate 40B and a support member 50B is inserted through it. However, the configuration is not limited to this, and the support member may be omitted, and the shielding plate 40B may be held by an auxiliary support part 70B. With this configuration, the advantage is that the holding structure of the shielding plate 40B can be made simpler and less expensive to manufacture. [Embodiment 3]

[0061] In Embodiments 1 and 2, an example was described in which a plurality of support members 50 or 50B are provided inward from the outer periphery of the block surface of each battery block 10 to support the shielding plate 40 or 40B. However, the power supply device of this disclosure is not limited to the above-described embodiment. Figure 10 shows a cross-sectional view of a part of the power supply device 100C according to Embodiment 3. In Figure 10, the same reference numerals are used for the same components as those described in Embodiment 1 and the above-described embodiment, and detailed descriptions are omitted as appropriate. In this power supply device 100C, the support member 50C is further provided with a third support member 53C in the central portion of the first block surface 11 and the second block surface 12 of each battery block 10.

[0062] The shielding plate 40C according to Embodiment 3 has a certain degree of rigidity, similar to the shielding plate 40B of Embodiment 2. In other words, the gas discharge space is made variable by tilting the shielding plate 40C, rather than by deforming a part of the shielding plate 40C. Specifically, the central portion of the shielding plate 40C is held in a tiltable manner by third support members 53C provided on the first block surface 11 and the second block surface 12, respectively. Any configuration that can support the shielding plate 40C in a tiltable manner can be appropriately used for these third support members 53C.

[0063] For example, the third support member 53C is formed in a triangular prism shape and is in linear contact with the shielding plate 40C, supporting it so that it can tilt around the axis of rotation shown as a black dot in Figure 10. It is preferable that the vertex of the triangular prism shape of the third support member 53C is curved rather than acute. Alternatively, a boss may be made to protrude from the end face of the shielding plate 40C as the axis of rotation of the shielding plate 40C, and an axial hole for receiving the boss may be formed in the third support member 53C, thereby enabling tilting. Alternatively, the third support member 53C may be made conical, and the center of the shielding plate 40C may be recessed to support it at a single point, thereby enabling tilting in all 360° directions.

[0064] Furthermore, it is preferable to appropriately add a positioning mechanism to enable smooth tilting of the shielding plate 40C. In the example shown in Figure 10, in addition to the third support member 53C, a shielding plate opening 41 is opened in the inner portion of the outer circumference of the shielding plate 40C, similar to the power supply device according to Embodiment 2, and the first support member 51C and the second support member 52C are inserted through it for positioning.

[0065] With this configuration, the shielding plate 40C can move in the rotational direction indicated by arrow d4 in Figure 10, with the third support member 53C as the pivot point. In this state, as shown in Figure 11, if gas is ejected from the battery cell 1L of the battery block 10-1, the end 42Ca of the shielding plate 40C on the side closer to the battery cell 1L moves towards the battery block 10-2 due to the pressure of the high-temperature, high-pressure gas, forming a gas discharge channel B. On the other hand, the opposite end 42Cb of the shielding plate 40C moves towards the battery cell 1L from which the gas was ejected, so as to close the insulating space 30. As a result, a gas discharge channel B is formed on the side closer to the battery cell 1L from which the gas was ejected, and the ejected gas is discharged along the shortest path.

[0066] As described above, according to the power supply device of this embodiment, by not fixing the shielding plate and making it a floating type, the volume of the gas discharge passage partitioned by the shielding plate is made variable, and a wide passage can be secured on the side from which the gas is discharged. In other words, in the space that forms the gas discharge passage provided between opposing battery cells, the position of the shielding plate is made variable, thereby partitioning the two gas discharge passages in a common space.

[0067] As a result of adopting this configuration, the gas exhaust channel, which is not used for most of the time, is reduced in size when not in use, thereby avoiding an increase in the size of the power supply unit. At the same time, in the event of a gas release, the gas exhaust channel on the affected side is made wider, thus ensuring the same level of safety. In particular, since the possibility of a gas release is extremely low, even if a release does occur, it is assumed to be from one of many secondary battery cells. Therefore, the gas exhaust channels, which were conventionally provided uniformly for multiple secondary battery cells, are reduced in size for each, while the gas exhaust channel on the unused side is used when in use, thereby ensuring the same channel volume as before and achieving the advantage of not compromising safety. [Industrial applicability]

[0068] The power supply device of the present invention can be suitably used as a power source for electric vehicles such as electric bicycles, electric scooters, electric carts, and electric automobiles, as well as a power source for energy storage devices used in homes and factories. [Explanation of symbols]

[0069] 100, 100B, 100C…Power supply 1…Battery cell 1L, 1R... Battery cells from which gas has been released 2…Outer can 3…Discharge valve 4…End electrode 4a...First end electrode 4b…Second end electrode 5… Lead plate 10...Battery block 10-1, 10-2, 10-3… Battery Blocks 11…First block surface 12…Second Block Surface 13…Battery holder 13a... Insertion part 14…Opening 20…Outer case 30…Insulation space 40, 40B, 40C…shielding plate 41...Shielding plate opening 42...Free end 42Ca, 42Cb...ends 50, 50B, 50C... Support members 51, 51B, 51C...first support member 51a...Tip 52, 52B, 52C... Second support members 53C...Third support member 60...Battery assembly 70, 70B…Auxiliary support part 90, 900…Power supply device 910...Battery block 91…Secondary battery cell 92...Battery unit 93,920... Heat-resistant sheet 94, 930... Exhaust chamber 940…Exhaust port 95... Outer frame section A, A''...separation distance B, B'... channel

Claims

1. Each is formed in a cylindrical shape with the outer casing extended in one direction, and one end face of the cylindrical shape is equipped with a discharge valve for releasing gas when the internal pressure rises, and The plurality of battery cells are held in a plurality of battery blocks, each holding the outer casing in a parallel position and with the end faces of the outer casings in a flat plane, The plurality of battery blocks are arranged such that the block surface on the side where the end faces of the outer casing are aligned in the same plane is separated from the block surface of an adjacent battery block, with an insulating space between them, and a shielding plate is placed in the insulating space. A support member for the shielding plate is provided on each of the opposing block surfaces of the plurality of battery blocks, located inward from the outer periphery, A power supply device comprising, The aforementioned support member is A first support member provided on one of the two opposing battery blocks, A second support member is provided on the other block surface of the battery block at a position corresponding to the first support member, and is connected to the first support member via the shielding plate, Equipped with, A power supply device in which a shielding plate supported by the support member has a free end at its outer circumference that can be displaced with respect to the support member.

2. A power supply device according to claim 1, The shielding plate has a shielding plate opening formed at a position corresponding to the support member, A power supply device comprising inserting the support member through the opening in the shielding plate.

3. A power supply device according to claim 1 or 2, A power supply device in which a plurality of the support members are provided on each end face of the battery block.

4. A power supply device according to any one of claims 1 to 3, The support member is provided in the central portion of each end face of the battery block, A power supply device in which the shielding plate is movable in the rotational direction with respect to the support member.

5. A power supply device according to any one of claims 1 to 4, further, A power supply device comprising a plurality of auxiliary support parts that melt with heat, provided between each of the opposing block surfaces of the plurality of battery blocks.

6. A power supply device according to any one of claims 1 to 5, The shielding plate is made of carbon fiber, silica fiber, glass fiber, or a flexible material obtained by impregnating these with resin.

7. A power supply device according to any one of claims 1 to 5, The shielding plate is made of a metal plate, a metal plate with insulating material bonded to both sides, a metal plate with insulating treatment applied to both sides, a mica sheet, or a flame-retardant fiber in the power supply device.

Images