Battery module

Abstract

This battery module comprises an assembled battery (4) in which a plurality of battery blocks (3) are connected in an axial direction of a plurality of cylindrical batteries (1), which are provided in each of the battery blocks (3) with bottom surfaces (11a) disposed on one and the same plane. The assembled battery (4) is provided with a cooling plate (5) for cooling the cylindrical batteries (1). Each of the battery blocks (3) has one end surface providing a cooling surface (3A) on which the bottom surfaces (11a) of the cylindrical batteries (1) are disposed, and another end surface providing a discharge surface (3B) on which opening portions (13) of discharge valves of the cylindrical batteries (1) are disposed. The assembled battery (4) has a duct gap (6) between adjacent battery blocks (3) for a discharged product. The cooling surface (3A) and the discharge surface (3B) are disposed on opposite surfaces of the duct gap (6). The cooling plate (5) has an L-shape in which a heat-absorption plate portion (5A) and a heat-dissipating plate portion (5B) are connected. The heat-absorption plate portion (5A) is stacked in a thermally coupled state on the cooling surface (3A). The heat-dissipating plate portion (5B) is disposed on an outer surface of the assembled battery (4). The duct gap (6) is located between the heat-absorption plate portion (5A) and the discharge surface (3B) of the battery blocks (3).

Description

[Technical Field]

[0001] The present invention relates to a battery module including a plurality of cylindrical batteries, and more particularly to a battery module capable of efficiently cooling cylindrical batteries. [Background technology]

[0002] In a battery module containing multiple cylindrical batteries, it is extremely important to efficiently dissipate the heat energy generated by the cylindrical batteries during charging and discharging, and to maintain the battery temperature within a set range. In particular, a battery module connects multiple cylindrical batteries in series or parallel to increase output capacity, and it is important to cool each cylindrical battery evenly and minimize temperature differences. This is because abnormal temperature increases or temperature variations in cylindrical batteries can degrade the battery's electrical characteristics and shorten its lifespan.

[0003] A battery module that dissipates the thermal energy of cylindrical batteries has been developed (see Patent Document 1). As shown in Fig. 11, this battery module has a large number of cylindrical batteries 91 arranged widthwise to form a right-side battery module 90A and a left-side battery module 90B, with heat transfer frames 92 stacked between the right-side and left-side battery modules 90A and 90B, and a cooling member 93 sandwiched between the right-side heat transfer frame 92A and the left-side heat transfer frame 92B. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2020-530936 Summary of the Invention [Problem to be solved by the invention]

[0005] 11 conducts thermal energy from the right and left battery modules 90 to a pair of heat transfer frames 92 to dissipate the heat, and a cooling member 93 is sandwiched between the pair of heat transfer frames 92, cooling both heat transfer frames 92 with the cooling member 93. In this battery module, a right heat transfer frame 92A and a left heat transfer frame 92B are stacked on both sides of the cooling member 93, and the cooling member 93 cools the heat transfer frames 92 stacked on both sides, so the cooling member 93 cannot dissipate heat from its surface, and further, because one cooling member 93 cools both heat transfer frames 92, the cooling member 93 has the disadvantage of requiring a large cooling capacity.

[0006] The present invention was developed with the aim of further overcoming the above drawbacks, and an object of the present invention is to provide a battery module that can efficiently cool a large number of cylindrical batteries. [Means for solving the problem]

[0007] A battery module according to one embodiment of the present invention includes a plurality of battery blocks each having the bottom surfaces of a plurality of cylindrical batteries arranged on the same plane; an assembled battery formed by connecting the plurality of battery blocks axially arranged along the cylindrical batteries; and a cooling plate for cooling the cylindrical batteries in the battery block. One end face of the battery block serves as a cooling surface formed by the bottom surfaces of the cylindrical batteries arranged on the same plane, and the other end face serves as a discharge surface formed by the openings of the discharge valves of the cylindrical batteries. The assembled battery has a duct gap between adjacent battery blocks for discharge, and adjacent battery blocks have a cooling surface and a discharge surface on opposite sides of the duct gap. The cooling plate has an L-shape formed by a heat absorption plate portion and a heat dissipation plate portion integrally connected at right angles. The heat absorption plate portion is thermally coupled to the cooling surface of the battery block, and the heat dissipation plate portion is arranged on the outer surface of the assembled battery. The assembled battery has a gap between the heat absorption plate portion of the cooling plate and the discharge surface of the battery block to form a duct gap for discharge. [Effects of the Invention]

[0008] The battery module described above can efficiently cool a large number of cylindrical batteries, preventing adverse effects caused by temperature rises in the cylindrical batteries. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a perspective view of a battery module according to one embodiment of the present invention; [Figure 2] FIG. 2 is a plan view of the battery module shown in FIG. [Figure 3] 3 is a vertical cross-sectional view of the battery module shown in FIG. 2 taken along line III-III. [Figure 4] FIG. 2 is an exploded perspective view of the battery module shown in FIG. 1, seen from the left side. [Figure 5] 2 is an exploded perspective view of the battery module shown in FIG. 1, viewed from below. FIG. [Figure 6] FIG. 2 is an exploded perspective view of a battery pack of the battery module shown in FIG. [Figure 7] FIG. 7 is a bottom perspective view of the battery pack shown in FIG. 6. [Figure 8] FIG. 2 is an exploded perspective view of the battery block. [Figure 9] FIG. 9 is an exploded perspective view of the battery block shown in FIG. 8, viewed from the left side. [Figure 10] FIG. 2 is an enlarged cross-sectional view showing the stacked state of battery blocks. [Figure 11] FIG. 1 is a vertical cross-sectional view of a conventional battery module. DETAILED DESCRIPTION OF THE INVENTION

[0010] One embodiment of the battery module of the present invention comprises a plurality of battery blocks each formed by arranging the bottom surfaces of a plurality of cylindrical batteries in the same plane; an assembled battery formed by arranging and connecting a plurality of battery blocks in the axial direction of the cylindrical batteries; and a cooling plate for cooling the cylindrical batteries in the battery block. One end face of the battery block serves as a cooling surface formed by arranging the bottom surfaces of the cylindrical batteries in the same plane, and the other end face serves as a discharge surface formed by arranging the openings of the discharge valves of the cylindrical batteries. The assembled battery has a duct gap for discharged matter between adjacent battery blocks, and adjacent battery blocks have a cooling surface and a discharge surface disposed on opposite sides of the duct gap. The cooling plate is L-shaped, with a heat absorption plate portion and a heat dissipation plate portion connected integrally at right angles. The heat absorption plate portion is thermally coupled to the cooling surface of the battery block, and the heat dissipation plate portion is disposed on the outer surface of the assembled battery. The assembled battery has a gap between the heat absorption plate portion of the cooling plate and the discharge surface of the battery block to form a duct gap for discharged matter.

[0011] The above battery module has the advantage of being able to efficiently cool a large number of cylindrical batteries. In particular, the above battery module allows for thermal coupling of each battery block with a separate cooling plate. Unlike conventional battery modules, this structure eliminates the need to thermally couple two sets of battery blocks to both sides of a single cooling plate. Relative misalignment between adjacent battery blocks does not impede the thermal coupling of the cooling plates. Each cooling plate is reliably positioned in thermal coupling with each battery block, allowing for efficient cooling of the cylindrical batteries with the cooling plates. In particular, the above battery module does not allow relative misalignment between adjacent battery blocks to impede thermal coupling. Therefore, even if adjacent battery blocks become misaligned relative to each other over long periods of use, the cylindrical batteries and the cooling plates can maintain a favorable thermal coupling state. This allows for stable cooling of cylindrical batteries with the cooling plates over long periods of time, preventing battery degradation and electrical performance degradation due to temperature rise.

[0012] Furthermore, the above battery module has a duct gap between the discharge surface of the battery block and the cooling plate, which blocks the high-temperature, high-pressure discharge air that is sprayed from the open discharge valve, thereby realizing the advantage that the cooling plate can prevent the induction of thermal runaway.In particular, the above battery module uses the cooling plate as a plate to prevent the induction of thermal runaway, so it achieves the advantage of being able to prevent the induction of thermal runaway with a simple structure without the need for a dedicated heat-resistant plate to prevent the induction of thermal runaway.

[0013] In a battery module according to another embodiment of the present invention, the assembled battery has a plurality of duct gaps, and a plurality of cooling plates are stacked on the cooling surfaces of the respective duct gaps, with the heat dissipation plate portions being arranged on the same plane.

[0014] The battery module described above has the advantage that cylindrical batteries can be cooled more effectively by thermally connecting a plate-shaped cooling member to a heat dissipation plate portion that is arranged on the same plane.

[0015] In another embodiment of the battery module of the present invention, the battery block includes a lead plate electrically connected to the bottom surface of each cylindrical battery, an insulating heat-conducting sheet is disposed between the lead plate and the heat-absorbing plate portion, and the heat-absorbing plate portion of the cooling plate is disposed in thermal connection with the bottom surface of the cylindrical battery via the insulating heat-conducting sheet and the lead plate.

[0016] The above battery modules have cooling plates stacked via insulating, heat-conductive sheets, which has the advantage of preventing short circuits caused by the cooling plates even though they are conductive.

[0017] In another embodiment of the battery module of the present invention, the battery blocks are provided with battery holders in which the cylindrical batteries are arranged in a parallel position, and the assembled battery has duct gaps between the battery blocks via the battery holders.

[0018] The above battery modules are constructed with protrusions on the battery holders that hold the cylindrical batteries in place, and duct gaps are provided between adjacent battery blocks, allowing the battery holders to maintain accurate duct gap spacing.

[0019] A battery module according to another embodiment of the present invention includes a forced cooling member that is thermally coupled to the heat dissipation plate portion.

[0020] The above battery module has the advantage that each cooling plate is efficiently cooled by the forced cooling member, thereby allowing the cylindrical batteries to be cooled more efficiently.

[0021] A battery module according to another embodiment of the present invention includes an outer case that houses a battery pack, the outer case including a pair of end plates arranged on both end surfaces of the battery pack, side plates that connect both sides of the end plates and are arranged on both sides of the battery pack, and a bottom plate that is arranged on the bottom surface of the battery pack, the bottom plate having an exposure opening for the heat dissipation plate portion, and the heat dissipation plate portion being exposed in the exposure opening.

[0022] In the battery module described above, the heat dissipation plate portion of the cooling plate is placed in the exposed opening of the bottom plate, so the cylindrical batteries can be efficiently cooled by the cooling plate while the bottom surface of the exterior case is closed by the bottom plate.

[0023] In another embodiment of the battery module of the present invention, the battery blocks are equipped with battery holders in which cylindrical batteries are arranged in parallel positions, and side plates are fixed to the battery holders. This battery module has the advantage that adjacent battery blocks are positioned in fixed positions by the side plates, so the duct gaps between adjacent battery blocks can be maintained at a fixed distance by the side plates.

[0024] In another embodiment of the battery module of the present invention, the battery blocks are equipped with battery holders in which each cylindrical battery is arranged in a parallel position, and a cooling plate is fixed to the battery holder. This battery module can be assembled by fixing the cooling plate to the battery blocks, which has the advantage that it is possible to efficiently assemble a battery pack comprising multiple bottom plates and cooling plates and to reliably maintain the cooling plate in thermal contact with the cylindrical batteries.

[0025] In a battery module according to another embodiment of the present invention, the battery block has a plurality of parallel blocks each formed by connecting a plurality of cylindrical batteries in parallel, and the parallel blocks are connected in series to one another.

[0026] The above battery module has the advantage that the total output voltage can be increased without increasing the number of battery blocks connected in series.

[0027] In a battery module according to another embodiment of the present invention, the assembled battery has adjacent battery blocks connected in series.

[0028] The above battery module can optimize the output voltage for a particular application by adjusting the number of battery blocks connected in series.

[0029] 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., "upper," "lower," and other terms including these terms) will be used as necessary. However, the use of these terms is intended to facilitate 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. Furthermore, parts that appear with the same reference numerals in multiple drawings indicate the same or equivalent parts or components. Furthermore, the embodiments shown below are specific examples of the technical concept of the present invention and are not intended to limit the present invention thereto. Furthermore, unless otherwise specified, the dimensions, materials, shapes, relative positions, etc. of the components described below are intended as examples and are not intended to limit the scope of the present invention thereto. Furthermore, the content described in one embodiment or example can also be applied to other embodiments or examples. Furthermore, the sizes and positional relationships of components shown in the drawings may be exaggerated for clarity of explanation.

[0030] (Embodiment 1) 1 to 10 includes a plurality of battery blocks 3 each formed by arranging the bottom surfaces of a plurality of cylindrical batteries 1 on the same plane, a battery assembly 4 formed by connecting a plurality of battery blocks 3 and arranging them in the axial direction of the cylindrical batteries 1, and a cooling plate that cools the cylindrical batteries 1 of the battery block 3. Furthermore, the battery module 100 described above houses the battery assembly 4 in an exterior case 30.

[0031] (Cylindrical battery 1) In the cylindrical battery 1 shown in the exploded perspective views of Figures 8 and 9, the opening of the outer can 11 is closed with a sealing plate 12. In this cylindrical battery 1, the sealing plate 12 is disposed on the discharge surface 1B, which is provided with a discharge valve (not shown), and the bottom surface 11a of the outer can 11 serves as the cooling surface 1A. In the cylindrical battery 1, the sealing plate 12 can serve as the positive electrode and the bottom surface 11a can serve as the negative electrode, or the sealing plate can serve as the negative electrode and the bottom surface can serve as the positive electrode. The outer can 11 and sealing plate 12 of the cylindrical battery 1 are made of metal plates. The outer can 11 is manufactured by pressing a metal plate into a cylindrical shape with a bottom. The sealing plate 12 is equipped with a discharge valve. A protruding electrode can be provided in the center of the sealing plate 12, and the discharge valve can be built into this protruding electrode. The outer can 11 contains electrodes (not shown). Furthermore, an electrolyte is also filled. In the cylindrical battery 1 shown in the figures, the opening edge of the outer can 11 is crimped along the outer edge of the sealing plate 12, so that the outer edge of the sealing plate 12 is insulated and airtightly connected to the opening of the outer can 11. To improve the insulation and airtightness between the sealing plate 12 and the outer can 11, a gasket (not shown) is sandwiched between the sealing plate 12 and the outer can 11. The gasket is a rubber-like elastic body made of an insulating material. In a cylindrical battery 1 with this structure, the opening edge of the outer can 11 is crimped to sandwich the sealing plate 12, creating a crimped ridge 14 along the outer edge of the sealing plate 12.

[0032] The cylindrical battery 1 has a built-in exhaust valve in the sealing plate 12. The exhaust valve opens when the internal pressure becomes abnormally high. When the exhaust valve opens, it ejects exhaust materials such as electrolyte and gas from inside the battery. The exhaust valve has an opening 13 in the sealing plate 12 through which the exhaust materials are ejected. The exhaust valve may include, for example, a valve body, an elastic body made of a spring that elastically presses the valve body, and a valve seat plate with a valve hole that is closed by the valve body, and the valve seat plate can be airtightly fixed to the underside of the sealing plate. This exhaust valve may have a gap between the valve seat plate and the protruding electrode, and the valve body and elastic body can be disposed in this gap. Under normal conditions, in other words, when the internal pressure of the battery is lower than the set pressure, the elastic body elastically presses the valve body against the valve hole in the valve seat plate, airtightly closing the valve hole and maintaining a closed state. When the battery pressure exceeds the set pressure, the internal pressure of the battery presses the valve body, opening the valve hole and opening the exhaust valve. In this state, the electrolyte and gas inside the battery are exhausted to the outside through openings 13 provided in the sealing plate 12. The sealing plate 12 has multiple openings 13 around its center. However, the exhaust valve is not limited to the above structure, and any other structure that opens when the pressure inside the battery exceeds the set pressure can be used.

[0033] For example, lithium-ion secondary batteries known as "18650" or "21700" can be used as cylindrical battery 1. However, since secondary batteries with optimal shapes and characteristics for each application are being developed, the present invention does not limit cylindrical battery 1 to the lithium-ion secondary batteries described above, and secondary batteries currently in use and those yet to be developed can also be used.

[0034] (Battery block 3) The battery block 3 has multiple cylindrical batteries 1 arranged in parallel rows and columns. One end face of the battery block 3 is a cooling surface 3A, and the other end face is a discharge surface 3B. The cooling surface 3A is flush with the bottom surfaces 11a of the cylindrical batteries 1. The discharge surface 3B faces the sealing plate 12 of the cylindrical batteries 1 and serves as a surface for discharging waste from the discharge valves provided on the sealing plate 12. The cooling surface 3A cools the cylindrical batteries 1 from the bottom surfaces 11a, and the discharge surface 3B is where the openings 13 of the discharge valves of the cylindrical batteries 1 are located.

[0035] (Lead plate 7) The battery block 3 electrically connects lead plates 7 to both ends of each cylindrical battery 1. The lead plates 7 can be electrically connected to the end faces of the cylindrical batteries 1, preferably by welding or other methods. The lead plates 7 connected to both ends of the cylindrical batteries 1 connect adjacent cylindrical batteries 1 in parallel. The lead plates 7 consist of a bottom connection lead plate 7A connected to the bottom surface 11a of the cylindrical batteries 1 and a sealing plate connection lead plate 7B connected to the sealing plate 12 of the cylindrical batteries 1. The battery block 3 in Figure 8 divides the entire cylindrical battery 1 into two parallel blocks 10. The bottom connection lead plate 7A and the sealing plate connection lead plate 7B are divided into two pieces, dividing the entire cylindrical battery 1 into two parallel blocks 10. The lead plates 7 divide the bottom connection lead plate 7A and the sealing plate connection lead plate 7B into two pieces to divide the entire cylindrical battery 1 into two parallel blocks 10. Each of the divided lead plates 7 connects the cylindrical batteries 1 that make up the parallel block 10 in parallel. Two sets of parallel blocks 10 are connected in series by a series connection lead plate 7C. The above battery block 3 can increase the output voltage of the battery block 3 by connecting multiple parallel blocks 10 in series, and can increase the output current by configuring the parallel blocks 10 with multiple cylindrical batteries 1 connected in parallel. Since the output voltage of a battery block 3 with parallel blocks 10 connected in series can be made an integer multiple of that of the cylindrical batteries 1 depending on the number of parallel blocks 10 connected in series, the output voltage of the battery block 3 can be adjusted by adjusting the number of parallel blocks 10 connected in series.

[0036] (battery holder) The battery block 3 is equipped with a battery holder 2 that holds each cylindrical battery 1 in a fixed position in a parallel orientation. The battery holder 2 is made by molding insulating plastic. As shown in Figures 8 and 9, the battery holder 2 has a cylindrical section 21 that fits around the outer surface of the cylindrical battery 1 to hold the cylindrical battery 1 in a fixed position in a parallel orientation. The battery holder 2 is molded in a shape that splits in the middle of the cylindrical section 21. This battery holder 2 is made up of two holder units 2A and 2B.

[0037] Each holder unit 2A, 2B is tapered so that the inner diameter of the cylindrical portion 21 increases toward both ends. The inclination of the tapered cylindrical portion 21 is approximately the same as the draft angle of the mold, and can be, for example, 5 degrees or less, preferably 3 degrees or less. The inner diameter of the cylindrical portion 21 is largest at the center and gradually decreases toward both ends. Because the cylindrical portion 21 holds the cylindrical batteries 1 inserted in place, its minimum inner diameter is approximately equal to or slightly larger than the outer diameter of the cylindrical batteries 1.

[0038] Although not shown, the holder units 2A and 2B have a mating protrusion on one connecting end surface, and a mating recess into which this mating protrusion is mated on the opposing connecting end surface, so that the mating protrusion and the mating recess can be connected to a mating structure and connected in a fixed position.

[0039] As shown in Figures 8 and 9, the battery holder 2 holds cylindrical batteries 1 in place by inserting them into the cylindrical sections 21 of the two holder units 2A and 2B. In other words, the cylindrical sections 21 of the two holder units 2A and 2B are inserted on either side of the cylindrical battery 1, and the two holder units 2A and 2B are linearly connected via the cylindrical battery 1. In other words, the divided holder units 2A and 2B can be connected to each other in a fixed position via the cylindrical battery 1. The cylindrical battery 1 is also held in place via the battery holder 2. Because the battery holder 2 with this structure is connected in a fixed position with the cylindrical battery 1 inserted into the cylindrical section 21, the divided holder units 2A and 2B can be connected in a fixed position without any special structure, such as screwing, gluing, or welding.

[0040] Furthermore, the battery holder 2 is equipped with a fitting 22 that secures the lead plate 7 in a fixed position, allowing the lead plate 7 to be positioned in a fixed position. The lead plate 7, which is positioned in a fixed position by the battery holder 2, can be positioned on the end face of the cylindrical battery 1 and electrically connected by welding or other methods. The battery holder 2, which positions both the lead plate 7 and the cylindrical battery 1 in fixed positions, allows for an electrical connection between the lead plate 7 and the cylindrical battery 1 without misalignment.

[0041] As shown in Figures 2 and 3, multiple battery blocks 3 are connected with a duct gap 6 between adjacent battery blocks 3. To ensure a consistent duct gap 6, the battery holder 2 shown in Figure 9 has gap-forming ribs 23 integrally molded from plastic on the end surface of the battery holder 2. The battery holder 2 shown in Figure 9 has multiple gap-forming ribs 23 that protrude from the discharge surface 3B of the battery block 3 toward the cooling surface 3A of the opposing battery block 3. The size of the duct gap 6 in this battery holder 2 can be determined by the amount of protrusion of the gap-forming ribs 23. The battery holder 2 has multiple gap-forming ribs 23 distributed in a balanced manner, allowing for a consistent duct gap 6 between adjacent battery blocks 3. The battery holder 2 has the tips of the gap-forming ribs 23 in contact with the end surface of the adjacent battery block 3, ensuring a consistent duct gap 6. Although not shown, the gap-forming rib 23 is connected to the adjacent battery holder 2 using a fitting structure, or is joined, or is connected using a locking structure, thereby providing a duct gap 6 of a certain dimension between the adjacent battery block 3.

[0042] (Battery 4) The battery pack 4 is made up of multiple battery blocks 3 arranged and connected in the axial direction of the cylindrical batteries 1. The battery pack 4 has multiple battery blocks 3 arranged in a straight line, with exhaust duct gaps 6 provided between adjacent battery blocks 3. Each battery block 3 that makes up the battery pack 4 has the same characteristics, number, and connection state as the cylindrical batteries 1.

[0043] The battery pack 4 is connected so that the cooling surface 3A and exhaust surface 3B of adjacent battery blocks 3 face each other across the duct gap 6. In this battery pack 4, all of the cylindrical batteries 1 constituting each battery block 3 are arranged in a parallel orientation. The battery pack 4 in FIG. 2 can increase output voltage by connecting adjacent battery blocks 3 in series. The battery pack 4 in FIG. 2 has four battery blocks 3 arranged linearly in the axial direction of the cylindrical batteries 1, so connecting the battery blocks 3 in series can increase output voltage four times that of the battery block 3. A battery pack 4 in which four battery blocks 3 are connected in series, each consisting of two parallel battery blocks 10, can increase output voltage eight times that of the cylindrical batteries 1. While connecting the battery blocks 3 in series increases output voltage, connecting the battery blocks 3 in parallel can also increase maximum output current. Therefore, the present invention is not limited to a battery pack 4 in which the battery blocks 3 are connected in series; the battery pack 4 can also connect the battery blocks 3 in series or in parallel.

[0044] As shown in Figures 6 and 7, the battery pack 4 is made up of battery blocks 3 of the same shape connected together in a position that arranges the cylindrical batteries 1 in a straight line. In the battery pack 4 of Figures 4 and 5, each battery block 3 is fixed to an exterior case 30 and placed in a fixed position. However, the battery pack 4 can also be connected in a fixed position by connecting the battery holders 2 of adjacent battery blocks 3, or the battery blocks 3 can be fixed to the exterior case 30 and then the battery holders 2 of adjacent battery blocks 3 can be fixed and placed in a fixed position.

[0045] The battery pack 4 in Figures 2 and 3 has four battery blocks 3 connected in a straight line, with three rows of duct gaps 6 between the battery blocks 3. The duct gaps 6 are provided between adjacent battery blocks 3, so a battery pack with three battery blocks connected in a straight line has two rows of duct gaps. A battery pack can also have five or more battery blocks connected in a straight line, so this battery pack has four or more duct gaps.

[0046] (Cooling plate 5) The cooling plate 5 is an L-shaped plate with excellent thermal conductivity, consisting of a heat absorption plate portion 5A and a heat dissipation plate portion 5B connected at right angles to form an integral structure. A metal plate such as aluminum is suitable for this cooling plate 5. For example, a 1mm to 4mm aluminum plate can be used as the metal plate. An aluminum cooling plate 5 is low-cost, has excellent thermal conductivity, and is lightweight and easy to process. However, the cooling plate 5 is not limited to aluminum; other materials with excellent thermal conductivity and heat resistance, such as graphite, which has excellent thermal conductivity in the plane direction, can also be used.

[0047] The cooling plate 5 has a heat-absorbing plate portion 5A thermally coupled to the cooling surface 3A of the battery block 3, and a heat-dissipating plate portion 5B positioned on the outer surface of the battery pack 4. In addition to cooling the cylindrical batteries 1 from their bottom surfaces 11a, the cooling plate 5 protects the cylindrical batteries 1 from high-temperature, high-pressure waste discharged through open exhaust valves, preventing thermal runaway. When a cylindrical battery 1 experiences thermal runaway, its internal pressure rises rapidly, opening the exhaust valve and spewing out high-temperature, high-pressure waste. The high-temperature, high-pressure waste discharged can trigger thermal runaway in the cylindrical batteries 1. The cooling plate 5 prevents high-temperature, high-pressure waste from directly blowing onto the bottom surfaces 11a of the opposing cylindrical batteries 1, thereby preventing thermal runaway in the cylindrical batteries 1. To ensure that the cooling plate 5 effectively prevents thermal runaway, a duct gap 6 is provided between the heat-absorbing plate portion 5A of the cooling plate 5 and the exhaust surface 3B of the battery block 3. The duct gap 6 diffuses the exhaust material sprayed from the exhaust valve to reduce the impact of the exhaust material. The wider the duct gap 6, the more effectively the impact of the exhaust material can be reduced. Therefore, the duct gap 6 is set to, for example, 2 mm or more, preferably 3 mm or more. However, since the duct gap 6 increases the overall length of the battery module 100, the duct gap 6 is set to, for example, 15 mm or less, preferably 10 mm or less. The pressure and temperature of the exhaust material discharged from the exhaust valve vary depending on the dimensions and characteristics of the cylindrical batteries 1. Therefore, the duct gap 6 is set to an optimal position taking into account the dimensions and characteristics of the cylindrical batteries 1, the dimensions required for the battery module 100, etc.

[0048] The heat-absorbing plate portion 5A of the cooling plate 5 is thermally coupled to the cooling surface 3A of the battery block 3 via the insulating thermally conductive sheet 8, and can be thermally coupled to the bottom surface 11a of the cylindrical batteries 1 while being insulated from the lead plates 7 of the battery block 3. The cooling plate 5, which is insulated from the battery block 3, can be thermally coupled to the lead plates 7, which are divided into multiple sections with different potentials, without short-circuiting. The insulating thermally conductive sheet 8 is a sheet with excellent insulation and thermal conductivity, and can be, for example, a sheet with a thickness of 0.2 mm or more and 5 mm or less. The insulating thermally conductive sheet 8 is sandwiched between the battery block 3 and the cooling plate 5 in a locally compressed state, with one side in contact with the cooling surface 3A of the battery block 3 and the other side in contact with the surface of the cooling plate 5. The insulating thermally conductive sheet 8 can be a sheet with excellent thermal conductivity, such as a flexible sheet made of thermally conductive particles such as alumina bound with a binder, or a silicone resin sheet. Furthermore, the insulating and heat-conducting sheet 8 can be laminated in a more efficient heat-conducting state by applying a heat-conducting paste such as silicon oil to the surface.

[0049] The cooling plate 5 is fixed to the cooling surface 3A of the battery block 3 with an insulating, heat-conductive sheet 8 sandwiched between them. In the battery block 3 shown in Figures 8 and 10, setscrews 25 that penetrate the cooling plate 5 are threaded into the battery holders 2 of the battery block 3, securing the cooling plate 5 to the battery block 3 with the insulating, heat-conductive sheet 8 sandwiched between them. The battery holders 2 are made of insulating plastic, and the cooling plate 5 is screwed into them, insulating the cooling plate 5 from the conductive parts of the battery block 3. This structure allows the cooling plate 5 to be secured to each battery block 3, and the battery blocks 3 with their secured cooling plates 5 connected in a linear fashion for assembly. This structure has the advantage of allowing efficient assembly of a battery module 100 consisting of multiple battery blocks 3, with each cooling plate 5 securely in close contact with the surface of the battery block 3 and secured in a desirable thermally coupled state.

[0050] As shown in FIG. 5, a battery module 100 equipped with multiple cooling plates 5 has the heat dissipation plate portions 5B of the multiple cooling plates 5 arranged on the cooling surface 3A of each duct gap 6 arranged on the same plane. As shown in FIG. 3, the multiple heat dissipation plate portions 5B arranged on the same plane can be thermally coupled to a planar forced cooling member 40 and forcibly cooled by the forced cooling member 40. The forced cooling member 40 can be forcibly cooled, for example, by circulating a cooling refrigerant inside, thereby efficiently cooling each cooling plate 5. Alternatively, the forced cooling member 40 can be forcibly cooled by providing multiple heat dissipation fins (not shown) on the surface opposite the stacking surface of the heat dissipation plate portions 5B (the bottom surface in FIG. 3). A forced cooling member with heat dissipation fins can be used to forcibly blow air through the heat dissipation fins for more effective cooling. Alternatively, the forced cooling member 40 can be a thick metal plate with increased latent heat, which can absorb thermal energy and cool the cooling plates 5.

[0051] (Outer case 30) The exterior case 30 houses the battery pack 4. The exterior case 30 shown in the exploded perspective views of Figures 4 and 5 includes a pair of end plates 31 arranged on both end surfaces of the battery pack 4, side plates 32 connected to both sides of the end plates 31 and arranged on both sides of the battery pack 4, a bottom plate 33 arranged on the bottom surface of the battery pack 4, and a top cover (not shown).

[0052] The end plate 31 consists of a first end plate 31A that is thermally coupled to the cooling surface 3A of the battery block 3 via a cooling plate 5 on one end surface (right side in FIG. 4) of the battery pack 4, and a second end plate 31B that is disposed on the discharge surface 3B side, which is the other end surface (left side in FIG. 4) of the battery pack 4. The first end plate 31A is a metal plate that is layered on the surface of the cooling plate 5, and its four corners are fixed to fixing bolts 34 of the bent pieces 32A of the side plate 32 via nuts 35.

[0053] The second end plate 31B consists of an inner plate 36 positioned on the discharge surface 3B of the battery pack 4 with a duct gap 6, and an outer plate 37 positioned outside the inner plate 36. The inner plate 36 has two rows of ribs 38A and 38B extending widthwise and projecting between it and the outer plate 37. One of the two rows of ribs 38A and 38B is located at the lower edge of the inner plate 36, and the other at the upper edge, providing space for the circuit board 15 between the two rows of ribs 38A and 38B. The inner plate 36 also has a rib 38C extending vertically from the middle of the upper rib 38A, forming terminal spaces 18 on both sides of the rib 38C for the placement of the positive and negative terminals 16 and 17. The circuit board 15 is equipped with circuits such as a protection circuit that controls the charging and discharging of the cylindrical battery 1. The outer plate 37 consists of a frame 37A and a cover plate 37B that closes the opening of the frame 37A. Like the inner plate 36, the outer plate 37 is arranged with a duct gap 6 on the discharge surface 3B side of the battery pack 4, and its four corners are fixed via nuts 35 to fixing bolts 34 provided on the bent pieces 32A of the side plate 32.

[0054] The side plates 32 are stamped metal plates with two rows of reinforcing ribs 32B extending longitudinally, and both end edges are bent inward to form bent pieces 32A. Fixing bolts 34 that secure the end plates 31 protrude outward from the bent pieces 32A. The side plates 32 also have through holes 32C for set screws 26 that secure the battery block 3 in place. The set screws 26 are inserted into the through holes 32C of the side plates 32 and screwed into the battery holders 2 of the battery block 3 to position the battery block 3 in place.

[0055] The bottom plate 33 is a plate-shaped insulating material such as plastic, and has an exposed opening 33A that guides the heat dissipation plate portion 5B of the cooling plate 5 inward using a fitting structure. The bottom plate 33 is thinner than the heat dissipation plate portion 5B or has the same thickness as the heat dissipation plate portion 5B, and is structured so that each heat dissipation plate portion 5B, which is arranged on the same plane, can be closely attached to the surface of the forced cooling member 40. The bottom plate 33 can be joined to the bottom surface of the battery block 3 using, for example, double-sided adhesive tape.

[0056] The top cover is a plate made of insulating material such as plastic, similar to the bottom plate 33, and is attached and fixed to the top surface of the battery pack 4 with double-sided adhesive tape or the like, covering the top surface of the exterior case 30. [Industrial Applicability]

[0057] The battery module according to the present invention is mounted on an electric vehicle or an electric heavy machine and can be suitably used as a power source for supplying electric power to a drive motor. [Explanation of symbols]

[0058] 100...Battery module 1...Cylindrical battery 2. Battery holder 2A, 2B...Holder unit 3...Battery block 3A…Cooling surface 3B…Discharge surface 4. Battery pack 5...Cooling plate 5A...Heat absorption plate 5B...heat dissipation plate 6...Duct gap 7...Reed plate 7A...Bottom connection lead plate 7B: Sealing plate connection lead plate 7C...Series connection lead plate 8...Insulating and heat-conducting sheet 10...Parallel blocks 11...Outer can 11a…Bottom surface 12...Sealing plate 13...Opening 14...Caulking ridge 15...Circuit board 16...Positive terminal 17...Negative terminal 18...Terminal space 21...Cylindrical part 22…Fitting part 23...Gap forming rib 25...Set screw 26...Set screw 30...Outer case 31...End plate 31A...First end plate 31B...Second end plate 32...Side plate 32A…Bending piece 32B...Reinforcing rib 32C…Through hole 33...Bottom plate 33A…Exposure opening 34...Fixing bolt 35...Nut 36...Inner plate 37...Outer plate 37A...Frame 37B...lid plate 38A, 38B, 38C...Ribs 40...Forced cooling element 90...Battery module 90A...Right battery module 90B: Left battery module 91...Cylindrical battery 92...Heat transfer frame 92A...Right side heat transfer frame 92B...Left heat transfer frame 93...Cooling member

Claims

1. a plurality of battery blocks each including a plurality of cylindrical batteries arranged with their bottom surfaces flush with one another; a battery pack formed by connecting a plurality of battery blocks arranged in the axial direction of the cylindrical battery; a cooling plate that cools the cylindrical batteries of the battery block, The battery block includes: One end surface is arranged flush with the bottom surface of the cylindrical battery as a cooling surface, the other end surface is a discharge surface on which an opening of a discharge valve of the cylindrical battery is disposed, The battery pack comprises: a duct gap for discharged material is provided between adjacent battery blocks; The cooling surface and the exhaust surface of the adjacent battery blocks are disposed on opposing surfaces of the duct gap, The cooling plate is The heat absorption plate section and the heat dissipation plate section are connected at right angles to form an L-shaped integral structure. the heat absorption plate portion is laminated on the cooling surface of the battery block in a thermally coupled state; the heat dissipation plate portion is disposed on an outer surface of the battery pack, The battery pack is a battery module in which a gap is provided between the heat absorption plate portion and the discharge surface of the battery block, and serves as the duct gap for discharge.

2. The battery module according to claim 1, the battery pack has a plurality of the duct gaps, A battery module in which a plurality of the cooling plates are stacked on the cooling surfaces of the duct gaps, and the heat dissipation plate portions are arranged on the same plane.

3. The battery module according to claim 1, the battery block includes lead plates electrically connected to the bottom surface of each of the cylindrical batteries; an insulating and heat-conducting sheet is disposed between the lead plate and the heat-absorbing plate portion; The heat-absorbing plate portion is disposed in thermal connection with the bottom surface of the cylindrical battery via the insulating and heat-conducting sheet and the lead plate.

4. The battery module according to claim 1, the battery block includes a battery holder in which each of the cylindrical batteries is arranged in a parallel position; The battery module is configured such that the assembled battery has the duct gaps between the battery blocks via the battery holders.

5. The battery module according to claim 1, The battery module includes a forced cooling member that is thermally coupled to the heat dissipation plate portion.

6. The battery module according to claim 1, an exterior case that houses the battery pack; The outer case is a pair of end plates disposed on both end surfaces of the battery pack; side plates arranged on both sides of the battery pack by connecting both side portions of the end plates; a bottom plate disposed on a bottom surface of the battery pack, the bottom plate has an opening for exposing the heat dissipation plate portion, The battery module is configured such that the heat dissipation plate portion is exposed through the exposure opening.

7. The battery module according to claim 6, the battery block includes a battery holder in which each of the cylindrical batteries is arranged in a parallel position; The side plate is fixed to the battery holder to form a battery module.

8. The battery module according to any one of claims 1 to 7, the battery block includes a battery holder in which each of the cylindrical batteries is arranged in a parallel position; The cooling plate is fixed to the battery holder, forming a battery module.

9. The battery module according to claim 1, The battery block has a plurality of parallel blocks each formed by connecting a plurality of the cylindrical batteries in parallel, and the parallel blocks are connected in series to one another to form a battery module.

10. The battery module according to claim 1, The assembled battery is a battery module formed by connecting adjacent battery blocks in series.

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