Battery pack

Abstract

This battery pack comprises: a core pack 3; and an exterior case 10. The exterior case 10 comprises: a body case 11 in which a peripheral wall 13 is connected to a bottom plate 12; and a lid case 14. The body case 11 comprises: a filling gap 21 in which a solidifying liquid 40 for fixing the core pack 3 is filled between an outer surface 4 and an inner surface 13a of the peripheral wall 13; a duct gap 22 for discharging a discharge material to the outside of the exterior case 10; and a sliding gap 23 in which a cushion material 30 for preventing leakage of the solidifying liquid 40 is arranged. The cushion material 40 is inserted in a compressed state to define the filling gap 21 and the duct gap 22, and the inner surface 13a of the peripheral wall 13 located in the sliding gap 23 of the body case 11 is provided as a tapered surface 13b that inclines such that a lower portion thereof is positioned more inwardly than an upper portion thereof.

Description

Battery pack

[0001] The present invention relates to a battery pack in which a battery core pack is fixed to an outer case, and more particularly to a battery pack in which a solidifying liquid that hardens when filled in an uncured state is filled into the outer case.

[0002] Battery packs in which a solidifying liquid is filled into the outer casing have been developed (see, for example, Patent Documents 1 and 2). In the battery pack disclosed in Patent Document 1, the core pack is screwed to the outer casing, a gap is created between the core pack and the outer casing, and this gap is filled with potting resin. In this battery pack, the potting resin is filled into the gap between the outer casing and the core pack to protect the core pack from external impacts and for explosion prevention purposes. In this battery pack, a gap is created between the core pack and the outer casing, and the core pack is screwed to the outer casing and filled with potting resin, so a structure for screwing to both the core pack and the outer casing is required. In the battery pack of Patent Document 1, a connecting piece is provided on the core pack that protrudes from the outer circumference, and a boss is provided that protrudes from the peripheral wall of the outer casing, and a set screw is inserted into a through hole in the connecting piece and screwed into the female screw hole of the boss to fix it in place. This battery pack has the problem that the external dimensions become larger due to the fixing structure provided on the core pack and the outer casing. In particular, this fixed-structure battery pack requires strength to firmly secure the heavy core pack to the outer casing in order to increase the charge and discharge capacity. Therefore, there is a challenge in that the fixing structure becomes larger, further increasing the external dimensions of the battery pack. Furthermore, since this structure of battery pack locally fixes the core pack to the outer casing with set screws, there is a challenge in that the volume occupied by the fixing structure becomes even larger in order to ensure sufficient strength to withstand vibration and shock.

[0003] Furthermore, Patent Document 2 discloses a battery pack in which a core pack and uncured potting resin are placed in a waterproof battery bag, the potting resin is cured and adhered to the core pack, and the outer shape of the waterproof bag is molded to the inner shape of the outer case and then housed in the outer case. However, although this battery pack allows for a smaller fixing structure for the core pack, it has the problem that the waste discharged when the battery cells inside the core pack overheat cannot be smoothly discharged outside the outer case.

[0004] Japanese Patent Application Laid-Open No. 2012-209135, Japanese Patent No. 5294575

[0005] The present invention has been developed for the purpose of further solving the above problems. One of the objects of the present invention is to reduce the occupied volume of the core pack, the exterior case, and the fixing structure, and while fixing the core pack to the exterior case, provide a battery pack capable of providing a duct gap for smoothly discharging the emissions of the battery cells to the outside in a preferable region. Another object of the present invention is to provide a battery pack that can be assembled simply, easily, and efficiently, and can be arranged in a fixed position of the exterior case on the core pack to improve the vibration resistance strength and the strength against impact. Note that the description of these objects and problems of the present disclosure does not prevent the existence of other objects and problems. Also, one aspect of the present disclosure does not need to solve all of these problems. Furthermore, other problems can be extracted from the description of the specification, drawings, and claims of the present disclosure.

[0006] A battery pack according to one embodiment of the present disclosure includes a core pack composed of a plurality of battery cells and an exterior case incorporating the core pack. The exterior case includes a main body case provided with a storage space having an upper surface opening formed by connecting a peripheral wall to a bottom plate, and a lid case closing the upper surface opening of the main body case. The main body case has a filling gap filled with a solidified liquid, which is a fixing filler for fixing the core pack to the main body case, between the outer surface of the core pack and the inner surface of the peripheral wall, a duct gap for discharging emissions from the core pack to the outside of the exterior case, and a sliding gap disposed at the boundary between the duct gap and the filling gap and provided with a cushioning material for preventing leakage from the filling gap of the solidified liquid to the duct gap. The cushioning material is inserted into the sliding gap in a compressed state to partition the filling gap and the duct gap, and the inner surface of the peripheral wall located in the sliding gap of the main body case is formed as a tapered surface inclined in a direction where the lower side is disposed inward from the upper side.

[0007] The above battery pack has the advantage of reducing the volume occupied by the fixing structure between the core pack and the outer case, allowing for smooth discharge of battery cell waste while fixing the core pack to the outer case. It also has the advantage of allowing for easy, simple, and efficient assembly of the core pack and outer case by inserting the core pack into the outer case. This feature is achieved by inserting the core pack into the main case, partitioning the duct gap and filling gap, and injecting solidifying liquid into the filling gap for assembly. Furthermore, the above battery pack has the advantage of improving vibration resistance and shock resistance by positioning the core pack in a fixed location in the outer case and supporting the core pack with solidifying liquid filling the filling gap.

[0008] This is a schematic perspective view showing a battery pack according to one embodiment. This is a schematic exploded perspective view of the battery pack in Figure 1. This is a schematic exploded perspective view of the core pack in Figure 2. This is a schematic horizontal cross-sectional perspective view along line IV-IV in Figure 1. This is a schematic horizontal cross-sectional view along line V-V in Figure 1. This is an enlarged cross-sectional view of the main part of Figure 5. This is a schematic vertical cross-sectional view along line VII-VII in Figure 1. This is a schematic exploded cross-sectional view of Figure 7 showing the insertion of the core pack. This is a schematic diagram showing the insertion of the core pack into the main case and the inserted state. This is a partially exploded perspective view of the core pack in Figure 2 viewed from below.

[0009] The form of this disclosure may be specified by the following configurations and features.

[0010] A battery pack according to one embodiment of the present disclosure comprises a core pack consisting of a plurality of battery cells and an outer case containing the core pack. The outer case comprises a main body case having a storage space with an upper opening, to which a peripheral wall is connected to a bottom plate, and a lid case that closes the upper opening of the main body case. The main body case comprises a filling gap between the outer surface of the core pack and the inner surface of the peripheral wall, which is filled with a solidifying liquid that is a fixing filler material used to fix the core pack to the main body case; a duct gap for discharging waste from the core pack to the outside of the outer case; and a sliding gap where a cushioning material is placed at the boundary between the duct gap and the filling gap to prevent leakage of the solidifying liquid from the filling gap to the duct gap. The cushioning material is inserted into the sliding gap in a compressed state to separate the filling gap and the duct gap, and the inner surface of the peripheral wall located in the sliding gap of the main body case is a tapered surface that slopes in a direction from top to bottom inwards. Note that "upper" refers to the side above "lower," i.e., the side with the top opening of the main case; "lower" refers to the side below "upper," i.e., the side with the bottom plate of the main case; and "inside" refers to the side with the center of the bottom plate (Figure 9, etc.).

[0011] The above battery pack has the advantage of reducing the volume occupied by the fixing structure between the core pack and the outer case, while still allowing the core pack to be fixed to the outer case. This is because, instead of providing a rigid fixing structure such as screws between the core pack and the outer case, a solidifying liquid is filled into the filling gap between the core pack and the outer case, and the solidifying liquid that hardens in the filling gap adheres tightly to the outer surface of the core pack and the inner surface of the peripheral wall over a wide area, supporting and fixing the core pack to the storage part of the outer case. Furthermore, fixing with solidifying liquid does not cause the problem of difficulty in designing screw fixing parts due to the accumulation of tolerances as the battery pack size increases. In addition, the above battery pack has the advantage of being able to quickly discharge high-temperature, high-pressure waste discharged from thermally runaway battery cells to the outside of the outer case through the duct gap while realizing a structure that securely fixes the core pack to the main case. This is because a duct gap is provided in the gap between the core pack and the inner surface of the main case's peripheral wall, separated from the filling gap by a cushioning material, allowing the battery cells' waste to be quickly discharged outside the outer case.

[0012] Furthermore, the above battery pack has the advantage of being easy, simple, and efficient to assemble. In particular, the above battery pack has a structure that securely fixes the core pack to the main case and allows the discharged battery cells to be quickly discharged outside the outer case, making assembly easy and convenient and enabling efficient mass production. This is because the core pack can be inserted into the storage space on the inside of the peripheral wall of the outer case, and a filling gap and a duct gap can be partitioned between the core pack and the inner surface of the peripheral wall with cushioning material. In this state, an uncured liquid solidifying liquid can be filled into the filling gap, and the filled solidifying liquid can be cured to fix the core pack to the main case. In other words, with the core pack inserted into the storage space of the main case, the cushioning material partitions the filling gap from the duct gap, and an uncured liquid solidifying liquid can be filled into the filling gap and cured in the filling gap without leaking into the duct gap, allowing for assembly. Furthermore, the above battery pack has the advantage of allowing the core pack to be inserted smoothly without damaging the cushioning material, and the cushioning material fits in a compressed state, preventing leakage of the solidified liquid. This is because the inner surface of the peripheral wall located in the sliding gap of the main case has a tapered surface that slopes in a direction from the top downwards toward the inside, and this tapered surface slopes in a direction that gradually compresses the cushioning material inserted into the sliding gap. Moreover, the above battery pack also has the advantage of being able to firmly position the core pack in the storage space of the outer case while reducing the volume occupied by the fixing structure, thereby improving vibration resistance and shock resistance. This feature is achieved by the fixing structure, which is filled with solidified liquid that has hardened in the filling gap partitioned by the cushioning material in the gap between the outer surface of the core pack and the inner surface of the peripheral wall, which is positioned in the fixed position of the outer case, filling the filling gap and integrating with the peripheral wall, supporting the core pack in the fixed position over a wide area in a surface contact state.

[0013] In other embodiments of the present disclosure, the battery pack can have tapered surfaces on both the inner surface of the peripheral wall forming the filling gap and the outer surface of the core pack. This configuration has the advantage that the effects of each tapered surface are more efficiently exerted due to the synergistic effect of making both the inner surface of the peripheral wall of the outer case forming the filling gap and the outer surface of the core pack tapered, reducing the concentration of sliding parts of the core pack during insertion, preventing damage and peeling of the cushioning material, and allowing the core pack to be inserted smoothly. Furthermore, the inner surface of the peripheral wall and the outer surface of the core pack keep the cushioning material in an appropriate compressed state, preventing leakage of the uncured solidified liquid. In addition, the outer case can support and fix the core pack in a more fitted state.

[0014] In other embodiments of the present disclosure, the inclination angle (β) of the tapered surface of the core pack can be made smaller than the taper angle (α) of the inner surface of the peripheral wall. In this configuration, since the inclination angle (β) of the tapered surface of the core pack is smaller than the taper angle (α) of the inner surface of the peripheral wall, the sliding gap gradually narrows toward the bottom due to the difference in the inclination angle of the tapered surface. The cushioning material inserted into the sliding gap that narrows toward the bottom adheres strongly to the inner surface of the peripheral wall and the outer surface of the core pack in the area inserted toward the bottom of the sliding gap, ensuring reliable leakage prevention. In this state, the uncured, liquid solidified liquid filling the sliding gap can accumulate at the bottom and reliably prevent leakage in the area prone to leakage. Therefore, in addition to allowing the core pack to be smoothly inserted into the inside of the peripheral wall, this structure has the advantage of more reliably preventing leakage of the liquid solidified liquid filling the sliding gap.

[0015] In other embodiments of the present disclosure, the battery pack, in the above embodiment, has a core pack that is a rectangular parallelepiped having a first outer surface, a second outer surface, a third outer surface, and a fourth outer surface, with a horizontal cross-sectional shape of a rectangle, the first outer surface and the third outer surface being on opposing surfaces, and the second outer surface and the fourth outer surface being on opposing surfaces, the peripheral wall of the main body case is a rectangle having a first peripheral wall, a second peripheral wall, a third peripheral wall, and a fourth peripheral wall, a filling gap is provided between the first outer surface and the first peripheral wall of the core pack and between the third outer surface and the third peripheral wall of the core pack, a duct gap is provided between the second outer surface and the second peripheral wall of the core pack and between the fourth outer surface and the fourth peripheral wall of the core pack, and sliding gaps can be provided on both sides of the filling gap. The above configuration has the advantage that the solidified liquid filling the two opposing surfaces hardens and fills the gaps, integrating with the surrounding wall, allowing the core pack to be tightly held and supported from both sides, and fixed in place in the outer case. Furthermore, the hardened solidified liquid elastically deforms to absorb vibrations and shocks, thereby increasing vibration and shock resistance. In addition, this battery pack structure does not require a fixing structure that physically fixes the core pack and outer case with rigid joints such as screws, thus reducing weight, enabling the support and fixing of large and heavy core packs, and eliminating the difficulty and strictness of design due to tolerances. Moreover, it eliminates the space required to fix the core pack to the main case, reducing the overall external size and increasing the charge / discharge capacity per unit volume of the battery pack.

[0016] In other embodiments of the present disclosure, the battery pack can use a closed-cell plastic foam as the cushioning material. This configuration has the advantage that, because the cushioning material is a closed-cell plastic foam, the compression ratio of the cushioning material can be increased, and the core pack can be inserted into the main case while compressing the cushioning material, thereby reliably and stably partitioning the filling gap and the duct gap. This is because the closed-cell plastic foam is compressed as the air bubbles are crushed, forming an air cushion, and it adheres tightly to the outer surface of the core pack and the inner surface of the peripheral wall.

[0017] In other embodiments of the present disclosure, the battery pack may have a bottom gap between the bottom surface of the core pack and the bottom plate of the main case, and the bottom gap may be filled with a solidifying liquid. This configuration has the advantage of improving vibration resistance and shock resistance because the solidifying liquid filled in the bottom gap between the bottom surface of the core pack and the bottom plate of the main case supports the bottom surface of the core pack in a surface contact state. In particular, this structure has the advantage of improving vibration resistance and shock resistance in battery packs with large charge / discharge capacity. This is because the solidifying liquid at the bottom, which is in close contact with the bottom surface of the heavy core pack, can support it over a wide area. The bottom gap is in communication with the filling gap, and the solidifying liquid at the bottom can support and fix the core pack in a state where it is connected to the solidifying liquid, and the solidifying liquid and the solidifying liquid at the bottom can be filled from the upper opening.

[0018] In other embodiments of the present disclosure, the battery pack can be configured such that the solidified liquid filling the gap hardens and solidifies to a softer degree than the solidified liquid filling the bottom gap. This configuration makes the hardness of the solidified liquid filling the gap between the outer surface of the core pack and the inner surface of the peripheral wall softer than the solidified liquid filling the bottom surface of the core pack. As a result, vibrations and shocks acting in the horizontal direction can be efficiently absorbed by the solidified liquid in the gap, and the bottom surface of the core pack can be supported by the hard, high-strength solidified liquid at the bottom to improve support and fixing strength, thereby increasing vibration resistance and shock resistance in the vertical direction.

[0019] In other embodiments of the present disclosure, the battery pack in the above embodiment may have a potting resin or adhesive as the solidified liquid filling the gap, and the solidified liquid at the bottom may be an adhesive.

[0020] In other embodiments of the present disclosure, the battery pack can have an epoxy resin-based, urethane-based, or silicone-based adhesive as the solidifying liquid at the bottom.

[0021] In other embodiments of the present disclosure, the battery pack may be configured such that the core pack has a first outer surface and a third outer surface, each having first protrusions projecting from the outer surfaces toward the peripheral wall, and the main body case has a first peripheral wall and a third peripheral wall, each having second protrusions projecting from the peripheral wall toward the outer surface of the core pack, with the first and second protrusions being embedded in a solidifying liquid filled in a filling gap. The above configuration has the advantage that the core pack can be firmly fixed by the main body case without displacement via the solidifying liquid, because the first and second protrusions are embedded in the solidifying liquid in the filling gap, with a plurality of first protrusions on the outer surface provided in the filling gap and one or more second protrusions provided on the peripheral wall between the first protrusions. This is because the first and second protrusions can increase the area in which the hardening solidifying liquid adheres and bonds to the outer surface and the peripheral wall in a surface contact state, and also act as reinforcing ribs between the outer surface and the peripheral wall.

[0022] In another embodiment of the present disclosure, the battery pack, in the above embodiment, has a first projection and a second projection, which are vertical ribs projecting perpendicularly from the outer surface and the peripheral wall, respectively, and the vertical ribs of the first projection and the second projection can extend from the lower to the upper part of the inner surface of the outer surface and the peripheral wall, respectively. The above configuration has the advantage that the first projection and the second projection, which are arranged to project from both sides of the outer surface and the peripheral wall into the filling gap, are vertical ribs, so that the uncured solidified liquid can be smoothly filled into the filling gap. In addition, the solidified liquid filled between the vertical ribs having an extension length that extends from the lower to the upper part hardens, which has the advantage that the vibration and impact strength in the thickness direction of the vertical ribs can be increased.

[0023] In another embodiment of the present disclosure, the battery pack, in the above embodiment, has a core pack in which the electrodes of multiple battery cells are arranged on the same plane, and lead plates are connected to the electrodes of each battery cell arranged on the same plane to form a lead plate connection surface, and the space between the lead plate connection surface and the inner surface of the peripheral wall is made into a duct gap, allowing the discharged material from the lead plate connection surface of the core pack to be discharged into the duct gap. The above configuration has the advantage that the duct gap can be made wide because the electrodes of multiple battery cells are arranged on the same plane, lead plates are connected to the electrodes of each battery cell to form a lead plate connection surface, and the space between this lead plate connection surface and the inner surface of the peripheral wall is made into a duct gap, allowing the discharged material from the battery cells to be smoothly discharged to the outside of the outer casing through the duct gap. This feature ensures high safety by preventing the harmful effect of high temperature and high pressure discharged material flowing through the duct gap inducing thermal runaway in other battery cells.

[0024] In other embodiments of the present disclosure, the battery pack may have a lid case that includes a gas discharge opening for discharging exhaust gas to the outside, which is connected to the duct gap. This configuration has the advantage that the exhaust gas discharged into the duct gap can be quickly discharged to the outside of the outer casing through the gas discharge opening of the lid case.

[0025] In other embodiments of the present disclosure, the battery pack can have an inclination angle (α) of the tapered surface on the inner surface of the peripheral wall set to 0.01 degrees or more and 5 degrees or less with respect to the vertical surface of the bottom plate. The above configuration has the advantage that, because the taper angle (α) of the inner surface of the peripheral wall is set to 0.01 degrees or more and 5 degrees or less, the cushioning material of the sealing material can be fixed to the surface of the core pack and smoothly inserted into the main body case, thereby facilitating and streamlining assembly. Furthermore, the cushioning material can be inserted while sliding smoothly between the outer surface of the core pack and the inner surface of the peripheral wall. In addition, since the cushioning material can be inserted in a state in which the filling gap and the duct gap can be reliably partitioned, the solidified liquid to be filled into the filling gap can be filled without leaking into the duct gap.

[0026] The present invention will be described in detail below with reference to the drawings. In the following description, terms indicating specific directions or positions (e.g., "up," "down," and other terms including these) will be used as needed. The use of these terms is for the purpose of facilitating the understanding of the invention with reference to the drawings, and the meaning of these terms does not limit the technical scope of the present invention. Also, parts with the same reference numerals appearing in multiple drawings indicate the same or equivalent parts or components. Furthermore, the embodiments shown below are concrete examples of the technical concept of the present invention and do not limit the present invention to the following. In addition, the dimensions, materials, shapes, relative arrangements, etc. of the components described below are intended to be illustrative, and not to limit the scope of the present invention unless specifically stated otherwise. Also, the content described in one embodiment or example is applicable to other embodiments and examples. Furthermore, the size and positional relationships of the components shown in the drawings may be exaggerated for the sake of clarity in the explanation. For example, the inclination angle in the schematic diagram of Figure 9 is exaggerated for illustrative purposes and does not represent an accurate angle. In this disclosure, directions, orientations, etc. may include approximate directions and orientations. For example, the vertical direction and orientation may include the approximately vertical direction and orientation, including the inclination of the tapered surface.

[0027] The battery pack disclosed herein does not specify the load side, but can be used, for example, as a power source for electric assist bicycles, forklifts, self-propelled robots for delivery, electric carts for golf courses, electric scooters, construction machinery, hybrid vehicles, and electric vehicles. It can also be used as a power source for portable electrical equipment such as wireless devices, electric cleaners, and power tools. Furthermore, it can be applied not only to power sources but also to cooling mechanisms for electrical equipment containing heat-generating elements. Alternatively, it can be used for stationary energy storage devices, such as battery packs for homes, businesses, and factories, or as backup power supplies for servers. It is particularly suitable for use in high-capacity, heavy-mass battery packs, and battery packs requiring vibration and shock resistance. (Embodiment 1)

[0028] The battery pack 100 illustrated in Figures 1 to 10 comprises a core pack 3 consisting of multiple battery cells 1 and an outer case 10 that houses the core pack 3. The outer case 10 in Figure 2 consists of a main case 11 and a lid case 14. The main case 11 has a storage space 11b with an open top, where a peripheral wall 13 is integrally connected around the bottom plate 12. The lid case 14 is fixed to the main case 11 and closes the top opening 11a. The main case 11 has a gap between the outer surface 4 of the core pack 3 and the peripheral wall 13, and this gap is provided with a filling gap 21 for filling with a solidifying liquid 40 that fixes the core pack 3 to the main case 11, a duct gap 22 for discharging waste from the core pack 3 to the outside of the outer case 10, and a sliding gap 23 for a cushioning material 30 arranged along the boundary between the duct gap 22 and the filling gap 21. The cushioning material 30 is inserted into the sliding gap 23 in a compressed state and positioned in a fixed location, separating the filling gap 21 and the duct gap 22, preventing the uncured solidified liquid 40 filling the filling gap 21 from flowing into the duct gap 22. The inner surface 13a of the peripheral wall 13 of the main body case 11, which has a storage space 11b inside, is provided with a tapered surface 13b that slopes inward from the top (top opening side) to the bottom (bottom plate side). (Core pack 3)

[0029] The core pack 3 arranges multiple battery cells 1 in fixed positions using a battery holder 6. Each battery cell 1 has a cell side and a pair of cell end faces that form the end faces of the cell side, and has a pair of cell electrodes, i.e., a positive electrode and a negative electrode. The cell electrodes can be provided on one or both cell end faces. This disclosure does not specify the shape, size, arrangement, or structure of the cell electrodes, and the cell electrodes can be provided on the cell end faces as convex or concave portions, or on substantially flat portions, and can also be provided on the cell side. Each battery cell 1 has a discharge valve, which opens in the event of an abnormality to prevent the battery case, such as the outer casing, from rupturing. Since the discharge valve opens in the event of an abnormality, the ejected gas, electrolyte, and other materials become high temperature and pressure, which can cause temperature damage and fire spread, and must be properly discharged outside the outer casing 10. Figure 3 shows a cylindrical battery for the battery cell 1. A lithium-ion battery is suitable for the battery cell 1. Lithium-ion batteries have a large charge / discharge capacity relative to their capacity and weight, and can make the battery pack 100 smaller and lighter while increasing the charge / discharge capacity. However, the battery pack described herein does not specify the shape, size, type, structure of the battery cells, the shape, number, or connection of the electrodes, and can use shapes other than cylindrical batteries, such as prismatic batteries, and can use all rechargeable secondary batteries that have already been developed or will be developed in the future, including non-aqueous electrolyte secondary batteries other than lithium-ion batteries and all-solid-state batteries.

[0030] Figure 2 shows an exploded perspective view of the battery pack 100. The core pack 3 in Figure 2 has outer surfaces 4, a first outer surface 4A, a second outer surface 4B, a third outer surface 4C, and a fourth outer surface 4D, and is a rectangular parallelepiped with a rectangular horizontal cross-sectional shape (Figure 5, including the schematic shape). The rectangular core pack 3 has the first outer surface 4A and the third outer surface 4C facing each other, and the second outer surface 4B and the fourth outer surface 4D facing each other. The core pack 3 has lead plates 7 on the second outer surface 4B and the fourth outer surface 4D, making the second outer surface 4B and the fourth outer surface 4D wider rectangles than the first outer surface 4A and the third outer surface 4C, so that the width of the duct gap 22 is larger than the width of the filling gap 21.

[0031] Figure 3 shows an exploded perspective view of the core pack 3 shown in Figure 2. The core pack 3 shown in Figures 2 and 3 consists of two sets of battery units 2A and 2B arranged side by side (horizontally) and stacked in the thickness direction via spacers 8a, forming a rectangular parallelepiped overall. Each of the pair of battery units 2A and 2B stacks multiple battery cells 1 in the height and depth directions of the core pack 3, with the unit end faces of the battery cells 1 facing each other and arranged on the same plane. The widths of the first outer surface 4A and the third outer surface 4C are determined by the height of the battery cells 1 and the number of battery units 2A and 2B, while the heights and widths of the second outer surface 4B and the fourth outer surface 4D are determined by the number of battery cells 1 and the number of stacks. Each of the battery units 2A and 2B is positioned in a fixed position with multiple battery cells 1 facing the same direction (first direction) in a parallel orientation using a plastic battery holder 6. The battery holder 6 in Figure 3 has a battery holder 6A and a battery holder 6B, and both battery holders 6A and 6B are provided with insertion parts for inserting and positioning the battery cell 1. Battery holder 6A and / or battery holder 6B are integrally molded with a cell end face support part that supports the cell end face of the battery cell 1 and prevents the battery cell 1 from falling out, and have an electrode window that exposes the cell electrodes provided on the cell end face of the battery cell 1, and further have a fitting part that guides the lead plate 7 and positions it in place. With this battery holder 6, the battery cell 1 is inserted into each insertion part of battery holder 6A, and battery holder 6B is stacked, fitted, and locked onto battery holder 6A to position the battery cell 1 in place. The battery units 2A and 2B are constructed by stacking battery holders 6A and 6B, with lead plates 7 placed in the mating portion of battery holder 6B, and welding the lead plates 7 to the positive and negative electrodes of the battery cells 1 by methods such as laser welding, allowing adjacent battery cells 1 to be connected in series or parallel. Each of the battery units 2A and 2B has an insulating material such as an insulation plate 8b stacked on the surface of the lead plates 7 to insulate the surface of the lead plates 7. The core pack 3 has two sets of battery units 2A and 2B positioned in predetermined locations with a spacer 8a in between, and is insulated. The core pack 3 (a pair of battery units 2A and 2B) can be assembled by stacking the lead plates 7 on opposing outer surfaces 4 (second outer surface 4B and fourth outer surface 4D).The pair of battery units 2A and 2B may have a connecting and fixing structure that allows them to fit and lock together. In the example shown in Figure 10, the fixing part 6b for fixing the pair of battery units 2A and 2B is located on the bottom surface 4a of the core pack 3.

[0032] The battery cell 1 has an outlet end face with an outlet valve on the cell end face, and the battery units 2A and 2B have their outlet end faces arranged on the same plane. The core pack 3 in Figures 2 and 3 has the outlet end faces of multiple battery cells 1 arranged on the second outer surface 4B and the fourth outer surface 4D side, forming an outlet surface. The core pack 3 has outlet surfaces on both opposing sides of the second outer surface 4B and the fourth outer surface 4D. That is, duct gaps 22 are arranged between the second outer surface 4B and the second peripheral wall 13B, and between the fourth outer surface 4D and the fourth peripheral wall 13D of the two opposing outlet surfaces. The core pack 3 has the cell electrodes of multiple battery cells 1 arranged on the same plane and is provided with lead plate connection surfaces for connecting lead plates 7 to the cell electrodes of each battery cell 1 arranged on the same plane, and these are arranged on the second outer surface 4B and the fourth outer surface 4D. The core pack 3 uses the space between the lead plate connection surface and the inner surface 13a of the peripheral wall 13 as a duct gap 22, and sends the waste discharged from the lead plate connection surface to the duct gap 22. The core pack 3 also has filling gaps 21 on both opposing surfaces of the first outer surface 4A and the third outer surface 4C, which are non-discharge surfaces. The filling gaps 21 are located between the first outer surface 4A and the first peripheral wall 13A, and between the third outer surface 4C and the third peripheral wall 13C.

[0033] The core pack 3 is provided with a plurality of first protrusions 5 that project from the outer surface 4 toward the outer peripheral wall 13. In Figures 4 and 5, the core pack 3 is provided with a plurality of first protrusions 5 that project into the filling gap 21 on the first outer surface 4A and the third outer surface 4C of the core pack 3. The first protrusions 5 are integrally molded with the plastic battery holder 6 and project toward the inner surface 13a of the peripheral wall 13. The plurality of first protrusions 5 provided on the core pack 3 in Figures 2 and 3 are provided on both the battery holder 6A and the battery holder 6B of the battery units 2A and 2B and project toward the filling gap 21. The core pack 3 is provided with a plurality of first protrusions 5 on opposing surfaces (the first outer surface 4A and the third outer surface 4C in Figures 4 and 5), so that the hardened solidified liquid 40 can position and fix the core pack 3 in the main case 11 without misalignment. The first protrusion 5 is a vertical rib 5a that protrudes vertically from the outer surface 4. The vertical rib 5a in Figures 2 and 4 is a longitudinal rib that extends in the vertical direction, from the bottom to the top of the outer surface 4. The main body case 11 in Figures 2, 4 to 6 is provided with a plurality of second protrusions 15 that protrude from the inner surface 13a of the peripheral wall 13 toward the inner outer surface 4. The second protrusions 15 are vertical ribs 15a that protrude vertically from the inner surface 13a of the peripheral wall 13, similar to the first protrusion 5, and are longitudinal ribs that extend in the vertical direction, from the bottom to the top of the inner surface 13a of the peripheral wall 13. The first and second protrusions 5 and 15 in Figures 4 to 6 extend linearly in the vertical direction. The direction of extension can be perpendicular to the bottom surface 4a and bottom plate 12, or it can be non-perpendicular, and it can be non-linear in whole or in part. Multiple first and / or second protrusions 5, 15 can be arranged in parallel positions, embedded in the solidifying liquid 40 that hardens in the filling gap 21, and can adhere closely to the outer surface 4 and peripheral wall 13, increasing the bonding area. They also act as reinforcing ribs for the outer surface 4 and peripheral wall 13, increasing the support and fixing strength of the core pack 3 via the first and second protrusions 5, 15 and the solidifying liquid 40. As the solidifying liquid 40 hardens, it fills the gap in the filling gap 21 and integrates with the peripheral wall 13, allowing the core pack 3 to be fixed to the outer case 10 by an anchoring effect. Multiple first and second protrusions 5, 15 are arranged in a comb-like pattern to efficiently improve the anchoring effect. (Outer case 10)

[0034] The outer case 10 houses and contains the core pack 3. The outer case 10 illustrated in Figures 1 and 2 consists of a main case 11 that has a storage space 11b for the core pack 3 inside, with a peripheral wall 13 along the outer surface 4 of the core pack 3 connected to the bottom plate 12, and a lid case 14 that closes the top opening 11a of the main case 11. The main case 11 has a peripheral wall 13 along the outer edge of a rectangular (square in Figure 2) bottom plate 12. The peripheral wall 13 is molded from plastic as an integral structure with the bottom plate 12 and is connected to each side of the rectangular bottom plate 12. The peripheral wall 13 connected to each side of the bottom plate 12 consists of a first peripheral wall 13A, a second peripheral wall 13B, a third peripheral wall 13C, and a fourth peripheral wall 13D. The first peripheral wall 13A and the third peripheral wall 13C are positioned opposite each other, and a predetermined gap of filling space 21 is provided between the inner surface 13a of the peripheral wall 13 and the outer surface 4 of the core pack 3. The peripheral walls 13 of the second outer surface 4B and the fourth outer surface 4D are also positioned opposite each other, and a predetermined gap of duct space 22 is provided between the inner surface 13a of the peripheral wall 13 and the outer surface 4 of the core pack 3. The battery pack 100 has the filling space 21 and the duct space 22 located within the inner surface 13a of different peripheral walls 13, with the filling space 21 located on one opposing surface and the duct space 22 located on the other opposing surface, and the adjacent surfaces alternately having the filling space 21 and the duct space 22.

[0035] The first to fourth peripheral walls 13A to 13D shown in the horizontal cross-sectional views of Figures 4 to 6 are provided with internal protrusions 16 that project inward from the inner surface 13a. As shown in the perspective view of Figure 2, the upper end of the internal protrusion 16 is a screw boss 16a into which a set screw 16b for fixing the lid case 14 is screwed. The screw boss 16a is not for fixing the heavy core pack 3, but is a small boss into which a set screw 16b for fixing the lid case 14 is screwed, and can be provided projecting into narrow duct gaps 22 and filling gaps 21. The internal protrusion 16 with the upper part being a screw boss 16a has a convex shape on the inner surface 13a, but a groove is provided on the outer surface 4 of the peripheral wall 13 to prevent the peripheral wall 13 from becoming thicker in this region, thereby reducing the weight of the main case 11 and preventing the occurrence of depressions on the outer surface 4 of the internal protrusion 16 due to shrinkage during plastic molding. (Duct gap 22, filling gap 21)

[0036] Between the peripheral wall 13 of the main case 11 and the core pack 3, there is a duct gap 22 for discharging waste from the battery cell 1 to the outside, and a filling gap 21 filled with solidifying liquid 40 to fix the core pack 3 to the main case 11. The solidifying liquid 40 is a liquid with fluidity and viscosity in its uncured state, and is a potting resin or adhesive that hardens when filled into the filling gap 21 in its uncured state. Epoxy resin-based, urethane-based, or silicone-based potting resins or adhesives can be used for the solidifying liquid 40. In the horizontal cross-sectional views of Figures 4 to 6, the battery pack 100 has gaps between the peripheral wall 13 of the main case 11 and the core pack 3, with the gap between the first peripheral wall 13A and the third peripheral wall 13C being the filling gap 21, and the gap between the second peripheral wall 13B and the fourth peripheral wall 13D being the duct gap 22. The filling gap 21 is filled with uncured solidified liquid 40 from above (upper opening 11a). The uncured solidified liquid 40 can be injected into the filling gap 21 when the core pack 3 is inserted into the main case 11 and the upper surface of the peripheral wall 13 is open. The duct gap 22 is a duct or flow path provided between the core pack 3 and the inner surface 13a of the peripheral wall 13, which discharges exhaust gas and other waste products from the battery cell 1 due to thermal runaway to the outside of the outer case 10. As shown in the horizontal cross-sectional views of Figures 4 to 6, the duct gap 22 is a gap provided between the insulation plate 8b provided on the opposite surface of the core pack 3 and the inner surface 13a of the peripheral wall 13. The duct gap 22 can be set to a gap that allows waste products from the thermally runaway battery cell 1 to be smoothly discharged to the outside of the outer case 10, for example, several mm or more.

[0037] As shown in the vertical cross-sectional views of Figures 7 and 8, the waste flowing into the duct gap 22 can be discharged to the outside of the outer casing 10 through a gas discharge opening 17 for high-temperature gas, etc., provided in the lid case 14. The gas discharge opening 17 in Figures 7 and 8 has a sheet attached to the upper surface of multiple through holes (not shown) in the bottom surface of a recess provided in the lid case 14. The sheet peels off and melts due to the pressure and high temperature of the waste, and the exhaust gas is discharged to the outside of the outer casing 10 through the through holes.

[0038] The battery pack 100 shown in the cross-sectional views of Figures 2, 7, and 8 has a circuit board 9 fixed on top of a core pack 3. The circuit board 9 is connected to the core pack 3 and has electrical components mounted on it, such as a protection circuit that controls the charging and discharging of the battery cells 1. Figure 7 shows that an upward gap 24 is provided between the circuit board 9 and the inner surface 13a of the peripheral wall 13 of the outer case 10 (lid case 14 and / or main case 11) through which discharged material can pass. The circuit board 9 causes discharged material from the duct gap 22 to collide with its lower surface and diffuse into the surrounding area, then redirects it to the upward gaps 24 provided on both ends of the circuit board 9 (both ends of the first and third outer surfaces 4A and 4C), flows along the inner surface 13a of the lid case 14, and is discharged to the outside of the outer case 10 through the gas discharge opening 17. This structure attenuates the energy of the discharged material between the circuit board 9 and the upward gap 24, allowing it to be discharged to the outside through the gas discharge opening 17.

[0039] The battery pack 100 in Figure 9 has a bottom gap 25 between the bottom surface 4a of the core pack 3 and the bottom plate 12 of the main case 11, and the bottom solidification liquid 41 is filled into the bottom gap 25. The bottom solidification liquid 41 can close the filling gap 21 and the lower end openings of the duct gap 22. The bottom solidification liquid 41 can be filled with uncured solidification liquid 40 at the bottom of the storage space 11b, and the core pack 3 is inserted into the inside of the peripheral wall 13 while it is still uncured and allowed to harden, thereby closing the bottom solidification liquid 41 and the lower end openings of the duct gap 22. Furthermore, the hardened bottom solidification liquid 41 also has the effect of bonding the bottom surface 3 of the core pack 3 to the bottom plate 12 of the main case 11, fixing the core pack 3 in a fixed position in the main case 11. Preferably, the bottom solidification liquid 41 is an epoxy resin that can firmly bond the core pack 3 to the bottom plate 12 of the main case 11, but silicone resin or urethane resin can also be used. Silicone resin and urethane resin have the advantage of improving the vibration resistance and impact resistance of the battery pack 100 due to their excellent cushioning properties. The solidifying liquid 41 at the bottom is filled into the bottom of the storage space 11b in an uncured state without inserting the core pack 3, and then the core pack 3 is inserted into the storage space 11b while the solidifying liquid 40 is still uncured, allowing it to adhere tightly to the bottom surface 3 of the core pack 3. In this state, the uncured solidifying liquid 40 hardens, adhering and fixing the core pack 3 to the bottom of the main case 11. With the solidifying liquid 41 at the bottom described above, the uncured solidifying liquid 40 filled into the bottom of the storage space 11b adheres tightly to the bottom surface 3 of the core pack 3 over a wide area without gaps, allowing the core pack 3 to be firmly fixed to the bottom plate 12 of the main case 11. Furthermore, by inserting the core pack 3 into the storage space 11b, which is filled with uncured solidifying liquid 40 at the bottom, the uncured solidifying liquid 40 is pushed out around the core pack 3 to a predetermined height, allowing it to harden while sealing the filling gap 21 and the lower end opening of the duct gap 22. The amount of solidifying liquid 40 pushed out around the core pack 3 can be adjusted by the amount of uncured solidifying liquid 40 filled into the storage space 11b. If too much solidifying liquid 40 is pushed out around the core pack 3, it will hinder the smooth discharge of the waste from the battery cell 1 into the duct gap 22, so it is adjusted to a position where the waste from the battery cell 1 can be discharged smoothly.If too little solidifying liquid 40 is pushed out around the core pack 3, the lower end opening of the duct gap 22 cannot be reliably closed. Therefore, the amount of solidifying liquid 41 filled at the bottom is adjusted to an amount that allows the discharged material from the battery cell 1 to be smoothly discharged into the duct gap 22 and that closes the lower end opening of the duct gap 22. The solidifying liquid 40 and the solidifying liquid 41 at the bottom can be the same or different of one or more types, and the amount and ratio can be adjusted for filling, allowing the hardness, elasticity, and vibration and shock absorption of the hardened state to be set within a certain range. For example, the hardened solidifying liquid 40 can be made hard to have high hardness and strength, allowing the core pack 3 to be supported and fixed without moving, or it can be made soft to absorb vibration and shock, providing high vibration and shock resistance. For example, the solidifying liquid 40 in the filling gap 21 can be hardened and solidified to be softer than the solidifying liquid 41 at the bottom of the bottom gap 25. The solidifying liquid 40 in the filling gap 21 can be potting resin or adhesive, and the solidifying liquid 41 at the bottom can be an adhesive. The solidifying liquid 41 at the bottom can be an epoxy resin-based, urethane-based, silicone-based, or other adhesive.

[0040] The core pack 3 can also be fixed to the main case 11 by using the solidifying liquid 40 injected into the filling gap 21 as the solidifying liquid 41 at the bottom. With the core pack 3 inserted into the storage space 11b, the unhardened solidifying liquid 40 is filled into the filling gap 21 and injected from the filling gap 21 into the gap between the bottom surface 3 of the core pack 3 and the bottom of the main case 11, thereby fixing the core pack 3 to the main case 11. (Cushioning material 30)

[0041] The cushioning material 30 is inserted and positioned in the sliding gap 23 at the boundary between the filling gap 21 and the duct gap 22, preventing the uncured solidified liquid 40 filling the filling gap 21 from leaking into the duct gap 22. A closed-cell plastic foam is suitable for the cushioning material 30. The cushioning material 30 can be made of a material or material that can be surface-treated. Surface treatment can improve the surface's sliding properties, reduce the coefficient of friction, allow for smoother insertion, and suppress damage and peeling. For example, microcellular polymer sheets and PORON (registered trademark) can be used. However, the cushioning material 30 is not limited to plastic foam; all materials that compress and elastically deform, such as rubber-like elastic materials like elastomers, can also be used. Closed-cell plastic foam has the advantage of being able to be smoothly inserted into the sliding gap 23 because the cells compress and elastically deform.

[0042] Since the solidifying liquid 40 is filled into the filling gap 21 in a fluid, uncured state, if there is a gap between the filling gap 21 and the duct gap 22 through which the uncured solidifying liquid 40 can flow, there is a problem in which the uncured solidifying liquid 40 filled in the filling gap 21 leaks into the duct gap 22. The solidifying liquid 40 that leaks into the duct gap 22 hardens in the duct gap 22, obstructing the discharge of waste products from the battery cell 1 to the outside. By inserting a cushioning material 30 at a position separating the filling gap 21 and the duct gap 22, it is possible to prevent the uncured solidifying liquid 40 from leaking from the filling gap 21 into the duct gap 22, thereby preventing this problem. The cushioning material 30 is inserted into the sliding gap 23 to seal the sliding gap 23 between the filling gap 21 and the duct gap 22, thereby preventing leakage of the solidifying liquid 40.

[0043] The horizontal cross-sectional view in Figure 5 shows that the cushioning material 30 (4) is placed at the corners near the four corners of the core pack 3 (outer case 10). The battery pack 100 shown in Figures 4 to 6 has cushioning material 30 placed along both sides of the filling gap 21 (left and right sides in Figure 5) to prevent leakage of the solidifying liquid 40. The battery pack 100 in this figure has a sliding gap 23 in a vertical position inside the first peripheral wall 13A and the third peripheral wall 13C, into which the cushioning material 30 is inserted along both sides of the filling gap 21. The arrangement of the cushioning material 30 ensures that the filling gaps 21 into which the solidifying liquid 40 is filled are located in a wide, planar area within each of the first and third peripheral walls 13A and 13C. The solidifying liquid 40 hardens in the opposing first and third peripheral walls 13A and 13C, supporting and fixing the core pack 3 on both sides. Furthermore, the duct gaps 22 can be maximized on both sides within the second and fourth peripheral walls 13B and 13D. In the horizontal cross-sectional view of Figure 5, the battery pack 100 has sliding gaps 23 on both sides of the first peripheral wall 13A and the third peripheral wall 13C, into which the cushioning material 30 is inserted in a compressed state. In Figure 6, the cushioning material 30 is inserted in a compressed state into the sliding gap 23 provided between the inner surface 13a of the peripheral wall 13 and the convex shape 6a on the surface of the core pack 3, preventing the unhardened solidifying liquid 40 filling the filling gaps 21 from leaking into the duct gaps 22. The convex shape 6a on the outer surface 4 of the core pack 3 forms a flat surface opposite the inner surface 13a of the peripheral wall 13, allowing the cushioning material 30 to make surface contact and adhere to it, effectively preventing leakage of the uncured solidified liquid 40 in a compressed state.

[0044] As shown by the arrow in FIG. 2, the cushion material 30 is adhered to the surface of the convex portion 6a of the battery holder 6, and the core pack 3 can be inserted inside the peripheral wall 13 and arranged in the sliding gap 23. The cushion material 30 has a length greater than or equal to the filling height of the solidified liquid 40 filled in the filling gap 21. The cushion materials 30 in FIGS. 2, 7, and 9 have a length extending from the upper part to the lower part of the outer surface 4 of the core pack 3. The cushion material 30 in the figure has a side surface contact portion 31 that contacts the side surface of the outer surface 4 of the core pack 3, and a bottom surface contact portion 32 that is connected to the side surface contact portion 31 and is folded back to the bottom surface 3 side to contact the bottom surface 3, and is adhered to the side surface and the bottom surface 3 of the outer surface 4 of the core pack 3 (battery holder 6). FIGS. 8 and 9 show that the core pack 3 with the cushion material 30 adhered thereto is inserted vertically into the storage space 11b of the main body case 11, and the cushion material 30 can be inserted into the sliding gap 23 without displacement. However, although not shown, the cushion material 30 can also be adhered to the inner surface 13a of the peripheral wall 13 of the main body case 11, the core pack 3 can be inserted into the storage space 11b, and the cushion material 30 can be arranged in the sliding gap 23.

[0045] The cushioning material 30 is inserted and positioned in the sliding gap 23 in a compressed state to prevent leakage of the solidified liquid 40. When the cushioning material 30 is inserted into the sliding gap 23 in this state, the frictional resistance during insertion is considerably large. This is because the cushioning material 30, which is designed to reliably prevent leakage of the solidified liquid 40, is inserted into the sliding gap 23 in a compressed state. The strong frictional resistance during insertion hinders the smooth insertion of the cushioning material 30 into its fixed position in the sliding gap 23. The frictional resistance of the cushioning material 30 can be reduced by decreasing the surface pressure, that is, the pressure pressing against the outer surface 4 of the core pack 3 and the inner surface 13a of the peripheral wall 13. However, this can cause the uncured solidified liquid 40 to leak into the duct gap 22. Therefore, in order to prevent leakage of the solidified liquid 40, it is required that the cushioning material 30 be inserted into the sliding gap 23 while pressing against both the outer surface 4 of the core pack 3 and the inner surface 13a of the peripheral wall 13. Since the cushioning material 30 is made of a compressible material such as plastic foam that can be freely deformed, it cannot be inserted into the sliding gap 23 when the core pack 3 is placed in the storage space 11b. This is because, in addition to the flexible and easily deformable physical properties required of the cushioning material 30, the frictional resistance on both sides increases when it is inserted while sliding. In particular, as the core pack 3 becomes larger, the length of the cushioning material 30 that is inserted and interferes with increases, and as the weight of the core pack 3 increases, excessive interference and friction are more likely to occur due to its own weight.

[0046] The cushioning material 30 can be bonded to the outer surface 4 of the core pack 3 and inserted into the sliding gap 23 at the time the core pack 3 is inserted into the storage space 11b. This is because the cushioning material 30 can be bonded to the core pack 3 on one side to prevent deformation, while the other side slides along the inner surface 13a of the peripheral wall 13 and is inserted into the fixed position. Alternatively, the cushioning material 30 can be bonded to the inner surface 13a of the peripheral wall 13 and positioned at the time the core pack 3 is inserted into the storage space 11b. In this case, insertion is possible because the peripheral wall 13, to which one side is bonded, prevents deformation of the cushioning material 30, while the other side slides along the outer surface 4 of the core pack 3 and is positioned in the sliding fixed position. The cushioning material 30 can be fixed in place while preventing deformation by adhering one side to the outer surface 4 of the core pack 3 or the inner surface 13a of the peripheral wall 13. However, in either insertion state, the cushioning material 30 slides against the inner surface 13a of the peripheral wall 13 or the outer surface 4 of the core pack 3. Therefore, the frictional resistance of the sliding surface hinders the smooth positioning of the cushioning material 30 in the sliding gap 23 while accurately positioning it.

[0047] To resolve the above issues, the inner surface 13a of the peripheral wall 13 forming the sliding gap 23 is made into a tapered surface 13b. The tapered surface 13b is inclined so that the lower part of the inner surface 13a of the peripheral wall 13 is positioned inward from the upper part, reducing the frictional resistance at the beginning of insertion of the cushioning material 30, and increasing the frictional resistance as it is inserted. At the connection point with the inner surface 13a of the peripheral wall 13, the upper part of the inner surface 13a of the peripheral wall 13 (upper opening 11a side) is set away from the vertical line of the bottom plate 12, and the distance away from the vertical line is greater than that of the lower part (bottom plate 12 side), and the tapered surface 13b is inclined so that the horizontal cross-sectional area of ​​the storage space 11b decreases from the entrance side (upper opening 11a) where the core pack 3 is inserted to the back side (bottom plate 12 side). The tapered surface 13b makes the storage space 11b narrower from top to bottom and further back. The inclination angle (α) of the tapered surface 13b with respect to the vertical can be, for example, 0.01 degrees or more and 5 degrees or less, preferably 0.05 degrees or more and 3 degrees or less, and more preferably 0.1 degrees or more and 2 degrees or less. The lower limit of the inclination angle (α) is more preferably 0.2 degrees or more, and the upper limit of the inclination angle (α) is more preferably 1 degree or less. If the inclination angle (α) is too small, friction will be large, and the frictional resistance will be particularly large at the beginning of inserting the cushioning material 30, and if the inclination angle (α) is too large, it will be difficult to reliably prevent leakage of the uncured solidified liquid 40 from the upper part of the cushioning material 30 when the cushioning material 30 is inserted into the storage space 11b. By providing a slight inclination angle (α) of the tapered surface 13b, there is a great effect on the ease of inserting the core pack 3 and preventing leakage of the uncured solidified liquid 40, and the cost-effectiveness is extremely high without any substantial increase in cost. Considering the shape, thickness, and elastic modulus of the cushioning material 30, the angle is set so that it can be smoothly inserted into the sliding gap 23 while reliably preventing leakage of the solidified liquid 40 in the inserted state. The tapered surface 13b is provided on both sides of the opposing positions of the first peripheral wall 13A and the third peripheral wall 13C of the opposing surface, so that the insertion of the core pack 3 (cushioning material 30) can be made smoother and easier, and excessive interference and friction with the cushioning material 30 can be reduced and prevented.

[0048] As shown in the schematic diagram of FIG. 9, the battery pack 100 further has a tapered surface 4b provided on the outer surface 4 of the core pack 3. By providing a tapered surface 4b on the outer surface 4 of the core pack 3 that inclines in the same direction as the tapered surface 13b, the interference portion of the cushioning material 30 during insertion is relieved from concentrating on the insertion tip side (bottom surface 4a side), preventing damage and peeling of the cushioning material 30, relieving the resistance during insertion, and making the insertion of the core pack 3 (cushioning material 30) smoother and easier. The tapered surface 4b also has an extremely high cost-effectiveness similar to the tapered surface 13b, and can fit the core pack 3 inserted into the storage space 11b into the storage space 11b. The tapered surface 4b can have the same or different degrees of inclination as the tapered surface 13b, and can be inclined parallel or non-parallel to the tapered surface 13b. FIG. 9 shows that the inclination angle (β) of the tapered surface 4b of the core pack 3 is made smaller than the taper angle (α) of the tapered surface 13b of the inner surface 13a of the peripheral wall 13, and the tapered surface 4b is made closer to the vertical line (vertical line) shown by a broken line than the tapered surface 13b. The sliding gap 23 gradually narrows downward due to the difference (α - β) in the inclination angles of the tapered surfaces 13b and 4b. The cushioning material 30 inserted into this sliding gap 23 can ensure that the region inserted into the lower part of the sliding gap 23 tightly adheres to the inner surface 13a of the peripheral wall 13 and the outer surface 4 to prevent leakage. The uncured solidifying liquid 40 filled in the sliding gap 23 can surely prevent leakage in the region where it accumulates at the bottom and is likely to leak. The tapered surface 4b is provided on both opposing surfaces of the first outer surface 4A and the third outer surface 4C of the opposing surfaces, and is arranged at the opposing position of the tapered surface 13b to compress the cushioning material 30, enabling the features of the tapered surfaces 4b and 13b to be more efficiently exerted.

[0049] The schematic diagram in Figure 9 is a cross-sectional diagram intended to make it easier to understand the deformation of the compressed cushioning material 30 when the core pack 3 is inserted into the storage space 11b of the main case 11. The core pack 3, to which the cushioning material 30 is bonded, descends in the direction indicated by the arrow in Figure 9 and is inserted into the storage space 11b inside the peripheral wall 13, compressing the cushioning material 30 to a suitable thickness and positioning the core pack 3 in its designated location in the storage space 11b. As the cushioning material 30 is inserted into the core pack 3, the frictional resistance in the initial stages of insertion is reduced, allowing the core pack 3 to be easily inserted into the storage space 11b. As insertion progresses, the frictional resistance and the degree of compression of the cushioning material 30 increase, and when the core pack 3 is positioned in its designated location, the cushioning material 30 is compressed to a degree that prevents leakage of the uncured solidified liquid 40. Therefore, the compressed cushioning material 30 has the advantage of preventing the core pack 3 from shifting position, positioning the core pack 3 in the fixed location in the storage space 11b, and preventing leakage of the solidifying liquid 40 from the cushioning material 30.

[0050] The cushioning material 30 has a shape and material that allows it to stop the water from entering the unhardened solidified liquid 40 when compressed. Depending on the elastic deformation rate, the degree of elastic deformation, compression, friction, and the tapered surfaces 4b and 13b, the cushioning material 30 may have the same or different shapes, widths, and heights, either overall or partially. For example, the cross-sectional area, width, and height of the section perpendicular to the stretching direction can be increased or decreased in the insertion direction (bottom contact surface 32 side). The higher the height of the cross-sectional area of ​​the cushioning material 30, the greater the water-stopping effect, and the lower the height, the less frictional resistance there is during insertion, allowing for smoother insertion.

[0051] The battery pack according to this disclosure can be suitably used as a battery pack that reduces the volume occupied by the fixing structure between the core pack and the outer case, and allows for smooth discharge of battery cell waste to the outside while fixing the core pack to the outer case. Furthermore, it can be suitably used as a battery pack in which the core pack and outer case can be assembled easily, simply, and efficiently by inserting the core pack into the outer case.

[0052] 100...Battery pack 1...Battery cell 2A, 2B...Battery unit 3...Core pack 4...Outer surface; 4a...Bottom surface, 4b...Tapered surface 4A...First outer surface, 4B...Second outer surface, 4C...Third outer surface, 4D...Fourth outer surface 5...First protrusion; 5a...Vertical rib 6, 6A, 6B...Battery holder; 6a...Convex shape, 6b...Fixing part 7...Lead plate 8a...Spacer, 8b...Insulation plate 9...Circuit board 10...Outer case 11...Main case; 11a...Top opening, 11b...Storage space 12...Bottom plate 13...Peripheral wall; 13a...Inner surface, 13b...Tapered surface 13A...First peripheral wall, 13B...Second peripheral wall, 13C...Third peripheral wall, 13D...Fourth peripheral wall 14...Lid case; 15...Second projection; 15a...Vertical rib 16...Inner projection; 16a...Threaded boss, 16b...Set screw 17...Gas discharge opening 21...Filling gap 22...Duct gap 23...Sliding gap 24...Rising gap 25...Bottom gap 30...Cushioning material 31...Side contact surface 32...Bottom contact surface 40...Solidifying liquid 41...Solidifying liquid at the bottom

Claims

A battery core pack consisting of multiple battery cells, The system comprises an outer case that incorporates the aforementioned core pack, The aforementioned outer casing is The main case has a storage space with an opening at the top, to which the surrounding walls are connected to the bottom plate, The main body case comprises a lid case that closes the opening on the top surface of the main body case, The aforementioned main body case is Between the outer surface of the core pack and the inner surface of the peripheral wall, A filling gap is formed by filling the core pack with a solidified liquid which is a fixing filler material, and the core pack is fixed to the main body case. A duct gap for discharging waste from the core pack to the outside of the outer casing, It is positioned at the boundary between the duct gap and the filling gap, The system includes a sliding gap in which a cushioning material is arranged to prevent the solidified liquid from leaking from the filling gap into the duct gap, The aforementioned cushioning material is It is inserted into the sliding gap in a compressed state, and separates the filling gap and the duct gap. The inner surface of the peripheral wall located in the sliding gap of the main body case is A battery pack with a tapered surface that slopes inward from the top, with the bottom facing inward. 　 A battery pack according to claim 1, The inner surface of the peripheral wall forming the aforementioned filling gap, A battery pack in which both outer surfaces of the core pack are tapered. 　 A battery pack according to claim 2, A battery pack in which the inclination angle (β) of the tapered surface of the core pack is smaller than the taper angle (α) of the inner surface of the peripheral wall. 　 A battery pack according to claim 1, The aforementioned core pack, A rectangular parallelepiped having a first outer surface, a second outer surface, a third outer surface, and a fourth outer surface, with a horizontal cross-sectional shape of a quadrilateral, The first outer surface and the third outer surface are arranged on opposing surfaces, and the second outer surface and the fourth outer surface are arranged on opposing surfaces, The peripheral wall of the main body case is A quadrilateral having a first peripheral wall, a second peripheral wall, a third peripheral wall, and a fourth peripheral wall, The aforementioned filling gap Between the first outer surface and the first peripheral wall of the core pack, Provided between the third outer surface and the third peripheral wall of the core pack, The aforementioned duct gap, Between the second outer surface and the second peripheral wall of the core pack, Provided between the fourth outer surface and the fourth peripheral wall of the core pack, The aforementioned sliding gap is A battery pack arranged on both sides of the aforementioned filling gap. 　 A battery pack according to claim 1, A battery pack in which the cushioning material is a closed-cell plastic foam. 　 A battery pack according to claim 1, There is a bottom gap between the bottom surface of the core pack and the bottom plate of the main body case, A battery pack in which the bottom gap is filled with a solidifying liquid. 　 The battery pack according to claim 6, The solidified liquid that fills the aforementioned gap is A battery pack that is filled in the gap at the bottom and has solidified to a degree softer than the solidified liquid at the bottom. 　 The battery pack according to claim 6, The solidified liquid filling the aforementioned gap is potting resin or adhesive. A battery pack in which the solidified liquid at the bottom is an adhesive. 　 The battery pack according to claim 6, The solidified liquid at the bottom, Battery packs made with epoxy resin, urethane, or silicone adhesives. 　 The battery pack according to claim 4, The aforementioned core pack is On the first outer surface and the third outer surface, It is equipped with a first projection that protrudes toward the peripheral wall, The aforementioned main body case is The peripheral wall comprises the first peripheral wall and the third peripheral wall. The core pack is further provided with a second projection that protrudes toward the outer surface, The first protrusion and the second protrusion are A battery pack embedded in the solidified liquid that fills the aforementioned gap. 　 A battery pack according to claim 10, The first protrusion and the second protrusion are These are vertical ribs that protrude perpendicularly from the outer surface and the peripheral wall, respectively. A battery pack in which the vertical ribs extend from the lower to the upper part of the outer surface and the inner surface of the peripheral wall, respectively. 　 A battery pack according to claim 1, The aforementioned core pack, The electrodes of multiple battery cells are arranged on the same plane. It has a lead plate connection surface formed by connecting lead plates to the electrodes of each battery cell, which are arranged on the same plane, The space between the lead plate connection surface and the inner surface of the peripheral wall is defined as the duct gap. A battery pack that discharges waste materials from the lead plate connection surface of the core pack into the duct gap. 　 A battery pack according to any one of claims 1 to 12, The aforementioned lid case, A battery pack equipped with a gas discharge opening that discharges exhaust gas, which is connected to the duct gap, to the outside.

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