Storage battery system

Abstract

The present invention suppresses a temperature rise of a battery cell caused by a bus bar plate connected to a first lead plate and a second lead plate. In a battery system (1) in which a first lead plate (7A) and a second lead plate (7B), which are connected to end surface electrodes of a plurality of battery cells (4A) constituting a battery block (4), are connected by a bus bar plate (3), and the battery cells (4A) are connected in series and in parallel, a cooling gap (5) is provided between the bus bar plate (3) and the battery block (4), and the cooling gap (5) is formed between the bus bar plate (3) and the battery block (4). When the temperature of the bus bar plate (3) rises due to Joule heat of a load current, the air in the cooling gap (5) is quickly floated, thereby suppressing the temperature rise of the specific battery cell (4A) caused by the bus bar plate (3).

Description

Technical Field

[0001] The present invention relates to a storage battery system in which a plurality of battery cells are electrically connected to a lead plate via a busbar plate. Background Art

[0002] The battery system can connect multiple battery cells in parallel to increase the maximum current output to the load, and connect multiple battery cells in series to increase the voltage supplied to the load. As the battery system, the following structure is used: the lead plates are connected to the electrodes at the upper and lower ends of the multiple battery cells to connect the battery cells in parallel, and the upper and lower lead plates are connected through a busbar plate to connect the battery cells in series. (Patent Documents 1, 2)

[0003] like Fig.10 As shown, the above storage battery system is configured with multiple rows of lead plates in parallel on the upper and lower surfaces of the rectangular battery block, and multiple rows of busbar plates 903 that electrically connect the upper and lower lead plates are configured on the side of the battery block. The multiple rows of lead plates configured on the upper surface of the battery block are connected to the upper surface electrodes of the battery cells 904A, and the multiple rows of lead plates configured on the lower surface of the battery block are connected to the lower surface electrodes of the battery cells 904A, and the adjacent multiple battery cells 904A are connected in parallel to form a parallel block 904Ap of the battery. The busbar plates 903 configured in multiple rows are configured on the side of the battery block in a posture extending in the up and down direction, and the parallel blocks 904Ap of the battery are connected in series. The busbar plate 903 can electrically connect the upper and lower ends to the upper and lower lead plates to connect the parallel blocks 904Ap in series. The battery system 901 can produce the maximum current that can be output to the load by the number of batteries in the parallel block 904Ap, and can adjust the output voltage by the number of parallel blocks 904Ap connected in series with the busbar plate 903, so that the maximum current and output voltage output to the load are optimal values.

[0004] Prior Art Literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent No. 7069312

[0007] Patent Document 2: Japanese Patent Application No. 2021-503157 Summary of the invention

[0008] -Problems to be solved by the invention-

[0009] Fig.10The storage battery system 901 shown can increase the number of battery cells 904A connected in parallel in the parallel block 904Ap to increase the maximum current output to the load, but the heat energy due to Joule heat increases in the busbar plate 903, which is the sum of the currents flowing through the battery cells 904A constituting the parallel block 904Ap, i.e., the total current of the parallel block 904Ap. Therefore, there is a disadvantage that the busbar plate 903, whose temperature has risen due to Joule heat, heats the battery cells 904A arranged close to it, thereby raising their temperatures.

[0010] A further problem is that the above storage battery system has the following drawbacks: in a use environment where the temperature of the busbar plate rises, the temperature of the battery cell also rises, and the busbar plate with a rising temperature heats the battery cell with a rising temperature, and the busbar plate promotes the temperature rise of the battery cell. This is because, in the storage battery system, when the output current increases, the current of both the battery cell and the busbar plate increases, and the heat energy based on the Joule heat of the current increases. In particular, the heat energy of the busbar plate through which the total current of the battery cell flows increases, and the battery cell with a rising temperature is further heated. Therefore, in the above storage battery system, it is particularly important to reduce the heat energy of the busbar plate heating the battery cell. Furthermore, if the battery cell located in a close position opposite to the busbar plate is further heated by the busbar plate with a rising temperature when its own temperature rises due to the load current, the temperature rise is accelerated and the temperature rises significantly.

[0011] Furthermore, it is important for a battery system having multiple battery cells to suppress the temperature rise of a specific battery cell to reduce the temperature difference of all battery cells. This is because the temperature rise of a specific battery cell will affect the electrical characteristics and life of the battery system as a whole. This is because, for example, the following disadvantages may occur: a specific battery cell that has deteriorated due to temperature rise will shorten the life of the entire battery system and limit the maximum current output by the battery system. In order to suppress the temperature rise of a specific battery cell, it is also extremely important to suppress the temperature rise of battery cells that are prone to temperature rise and to reduce the temperature difference of each battery cell while supplying power to the load. Since the total current flowing through the parallel block of batteries in the busbar plate has a large thermal energy based on the Joule heat of the current, in the above battery system, it is an extremely important characteristic to suppress the heating of the battery cells by the busbar plate.

[0012] The present invention has been developed to solve the above problems, and therefore an important object of the present invention is to provide a battery system capable of suppressing a temperature rise of battery cells caused by busbar plates and suppressing adverse effects caused by temperature differences of battery cells.

[0013] -Methods for solving the problem-

[0014] The battery system comprises: a battery block having a plurality of battery cells; a plurality of first lead plates arranged on the upper surface of the battery block and connected to the end electrodes of the battery cells; a plurality of second lead plates arranged on the lower surface of the battery block and connected to the end electrodes of the battery cells; and a plurality of busbar plates electrically connecting the upper and lower ends to the first lead plates and the second lead plates, which are arranged on the side of the battery block in a posture extending in the up-down direction, and a cooling gap with air permeability extending in the up-down direction is provided between the busbar plate and the battery block.

[0015] -Effects of the Invention-

[0016] The above-described storage battery system can suppress the temperature increase of the battery cells caused by the bus bar plates, and can prevent the adverse effects caused by the temperature difference of the battery cells. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is an exploded perspective view showing a battery system and an outer case according to an embodiment of the present invention.

[0018] Figure 2 yes Figure 1 A perspective view of the battery system shown.

[0019] Figure 3 It is shown Figure 2 A perspective view of the opposite side of the battery system is shown.

[0020] Figure 4 Observe from below Figure 1 A perspective view of the battery system shown.

[0021] Figure 5 This is an enlarged perspective view of the battery system showing a state in which the busbar plate is separated from the battery block.

[0022] Figure 6 It is shown Figure 1 An enlarged vertical cross-sectional view of a connection portion between a lead plate and a busbar plate of a battery system is shown.

[0023] Figure 7 is an enlarged horizontal cross-sectional view of the upper portion of the battery system.

[0024] Figure 8 It is an enlarged horizontal cross-sectional view of the central part of the battery system.

[0025] Fig. 9 This is the circuit diagram of the battery system.

[0026] Fig.10 This is a perspective view of a conventional storage battery system. DETAILED DESCRIPTION

[0027] Hereinafter, the present invention will be described in detail based on the accompanying drawings. In addition, in the following description, as needed, terms indicating specific directions and positions (for example, "upper", "lower" and other terms containing these terms) are used, but the use of these terms is to facilitate the understanding of the invention with reference to the accompanying drawings, and the technical scope of the present invention is not limited by the meaning of these terms. In addition, the parts with the same symbols appearing in multiple drawings represent the same or equivalent parts or components. Further, the embodiments shown below represent specific examples of the technical ideas of the present invention, and the present invention is not limited to the following. In addition, the size, material, shape, relative configuration, etc. of the structural parts described below, as long as there is no specific description, are not intended to limit the scope of the present invention to this only, and are intended to be exemplified. In addition, the contents described in one embodiment and the embodiment can also be applied to other embodiments and embodiments. In addition, the size, positional relationship, etc. of the components shown in the drawings are sometimes exaggerated in order to make the description clear.

[0028] A battery system according to one embodiment of the present invention comprises: a battery block having a plurality of battery cells; a plurality of first lead plates arranged on the upper surface of the battery block and connected to the electrodes of adjacent battery cells; a plurality of second lead plates arranged on the lower surface of the battery block and connected to the electrodes of adjacent battery cells; and a plurality of busbar plates arranged on the side of the battery block in a posture extending in the up-down direction, electrically connecting the upper and lower ends to the first lead plate and the second lead plate, and providing a cooling gap having air permeability and extending in the up-down direction between the busbar plate and the battery block.

[0029] A battery system having a plurality of battery cells connects the plurality of battery cells in series and in parallel in order to set the output to the optimal voltage and maximum current for the application. The battery system configures the first lead plate and the second lead plate on the upper and lower surfaces of the battery block, and connects the first lead plate and the second lead plate to the upper and lower end surface electrodes of the battery cells, so that the battery cells can be connected in parallel. Furthermore, a bus bar plate is configured on the side of the battery block, and the battery cells are connected to the first lead plate and the second lead plate through the bus bar plate, so that the battery cells can be connected in series. The above battery system can connect the plurality of battery cells in series and in parallel through the first lead plate, the second lead plate and the bus bar plate, and set the output voltage and current to the optimal set values ​​for the application.

[0030] A battery system that connects multiple battery cells in series and in parallel can connect multiple battery cells in series and in parallel without providing a busbar plate, and only through lead plates arranged on the upper and lower surfaces of the battery block. This is because the battery cells can be connected in series and in parallel through lead plates arranged on the upper and lower surfaces of the battery block. However, the battery system connects the lead plates arranged on the upper and lower surfaces of the battery block to the positive and negative electrodes of the battery cells, so it is necessary to arrange the positive and negative electrodes of the battery cells on both the upper and lower surfaces of the battery block. The battery cell is provided with an opening of a discharge valve on one end electrode side, for example, on the positive electrode side, so the battery system ejects high-temperature, high-pressure exhaust gas from the discharge valve on both the upper and lower sides of the battery block. The exhaust gas becomes a cause of inducing various thermal obstacles in the battery system, such as inducing thermal runaway of other battery cells, or causing thermal obstacles to electronic components such as circuit substrates. A battery system that ejects exhaust gas on both upper and lower surfaces of a battery block requires exhaust ducts to be provided on both upper and lower surfaces of the battery block to guide the exhaust gas, which has disadvantages such as a complicated internal structure of the casing and an increased outer shape.

[0031] A battery system in which a busbar plate is arranged on the side of a battery block and battery cells are connected in series via the busbar plate can eliminate the above problems. However, there is a problem in which the temperature of a specific battery cell constituting the battery block rises, thereby deteriorating the temperature balance of the battery cell. In a battery system, the temperature balance of the battery cell is an extremely important characteristic. This is because a temperature rise in a battery cell causes a decrease in electrical characteristics. A battery system with poor temperature balance causes a decrease in electrical characteristics of specific battery cells, which shortens the life of the entire battery system. In a battery system in which a busbar plate is arranged on the side of a battery block, when the load current increases, both the busbar plate and the battery cell generate heat due to Joule heat, thereby causing the following problem: the busbar plate with increased temperature heats the battery cell with increased temperature, which accelerates the temperature rise of the specific battery cell.

[0032] In order to prevent the above disadvantages, the battery system of Patent Document 1 narrows the horizontal width of the central part of the busbar plate and provides a gap between adjacent busbar plates. The facing area between the busbar plate and the battery cell becomes smaller, which can suppress the temperature rise of the battery cell caused by the busbar plate. However, when the horizontal width is narrowed, the resistance of the busbar plate increases, so there is the following disadvantage: the heat energy caused by Joule heat that increases in proportion to the resistance increases, the temperature rise of the busbar plate becomes larger, and the battery cell is further heated.

[0033] As described above, the battery system in which the busbar plate is arranged on the side of the battery block has the advantage of being able to control the exhaust gas to one side of the upper and lower sides of the battery block, but there is a problem of promoting the temperature rise of a specific battery cell located at a position opposite to the busbar plate, thereby reducing the electrical characteristics of the specific battery cell. Therefore, the structure in which the busbar plate is arranged on the side of the battery block to connect the battery cells in series is advantageous for the thermal barrier caused by the exhaust gas, but since it affects the life of the entire battery system and worsens the temperature balance of the battery cells, eliminating the problem caused by heat becomes an obstacle.

[0034] When the load current of the battery system increases and the temperature of the battery cell increases, the busbar plate, which also increases in temperature, is arranged at a position opposite to the battery cell, which deteriorates the temperature balance and causes thermal failure of the battery system. The battery system according to the embodiment of the present invention arranges the busbar plate, which also increases in temperature and causes the temperature increase of the battery cell, on the side of the battery block, and provides a cooling gap whose heat insulation effect increases as the temperature of the busbar plate increases, thereby achieving excellent characteristics of suppressing the temperature increase of the battery cell caused by the busbar plate.

[0035] The battery system of this embodiment has a cooling gap between the busbar plate and the battery block, but the cooling gap is not a structure that simply provides an air layer between the busbar plate and the battery cell for heat insulation. In a state where it is required to suppress the rise in temperature of both the busbar plate and the battery cell, that is, in a temperature environment where the temperature rise of the battery cell is suppressed, the busbar plate with a rising temperature accelerates the floating speed of the internal air through the chimney effect of the cooling gap, effectively ventilates the internal air of the cooling gap, and thus improves the cooling effect. That is, the following ideal characteristics are achieved based on the heat insulation effect of the cooling gap: the higher the temperature of the busbar plate and the battery cell rises, the higher the heat insulation characteristics based on the chimney effect of the cooling gap, and the more the temperature rise of the battery cell can be suppressed. Therefore, the above battery system achieves the advantage of being able to connect the first lead plate and the second lead plate through the busbar plate to connect the battery cells in series, and further prevents the disadvantage of worsening the temperature balance by arranging the busbar plate on the side of the battery block, and achieves excellent effects such as being able to suppress the reduction of the electrical characteristics and the reduction of the life of the battery system as a whole.

[0036] A battery block of a storage battery system according to another embodiment of the present invention can connect a plurality of battery cells in parallel as a plurality of parallel blocks via a first lead plate and a second lead plate, and connect the parallel blocks in series via a bus bar plate.

[0037] In the above battery system, the total current of a plurality of battery cells connected in parallel by the first lead plate and the second lead plate flows through the busbar plate, thereby increasing the current of the busbar plate. In the busbar plate, the heat energy based on the Joule heat of the current increases, and the temperature rise increases. The higher the temperature rise of the busbar plate, the higher the temperature of the air on the inner surface of the busbar plate rises, and the lower the specific gravity of the air, which can make it float more smoothly. The air that floats up quickly along the inner surface of the busbar plate causes the internal air of the cooling gap to float as a whole. The floating internal air is discharged to the outside from the upper part of the cooling gap, and the non-heated air flows into the cooling gap from the lower part and from the outside of the cooling gap, thereby improving the heat insulation effect of the cooling gap. The cooling gap with improved heat insulation effect suppresses the temperature rise of the battery cells arranged in close proximity to the busbar plates at opposing positions. Therefore, even in the state where the total current of a plurality of battery cells flows and the temperature of the busbar plate rises, the above battery system can effectively suppress the temperature rise of the battery cells caused by the busbar plate. In particular, the above battery system has the following advantages: in a usage state where the temperature rise of the battery cell increases, that is, in a state where the heat generation energy of the busbar plate increases, the heat insulation effect of the cooling gap can be more effectively exerted, thereby suppressing the temperature rise of the battery cell caused by the busbar plate with increased temperature. In a usage environment where the load current of the battery system increases and the temperature of the battery cell rises, it is particularly important to reduce the temperature rise of the battery cell. Therefore, the above advantage of being able to reduce the temperature rise of the battery cell in a usage environment with a large load current is extremely important in the battery system.

[0038] The battery block of the battery system of another embodiment of the present invention can arrange the battery cells in a fixed position by a battery holder, and a cooling gap is set between the battery holder and the busbar plate. The battery system can more effectively suppress the temperature rise of the battery cells caused by the heated busbar plate through the double-layer insulation structure of the cooling gap and the battery holder. In the above battery system, the busbar plate with the increased temperature heats the opposite surface of the battery holder through the cooling gap by radiant heat, so the battery holder blocks the radiant heat from the busbar plate, and the busbar plate with the increased temperature forces the internal air of the cooling gap to float upward, achieving an effective insulation effect. Therefore, the temperature rise of the battery cells can be more effectively suppressed by the synergistic effect of the cooling gap with improved insulation effect and the blocking effect of the battery holder on radiant heat.

[0039] A battery system according to another embodiment of the present invention is capable of configuring a plurality of busbar plates in a parallel posture on the same plane, providing an insulating gap between adjacent busbar plates, in which an insulating ridge integrally constructed with a battery holder is provided, and the cooling gap is divided into a plurality of rows of cooling ducts extending in an up-and-down direction by the insulating ridge.

[0040] The above battery system has the following advantages: the chimney effect of the cooling duct extending in the vertical direction obtained by dividing the cooling gap can effectively suppress the temperature rise of the battery cell by the air floating in the cooling duct. The chimney effect is the following effect: in a chimney extending in the vertical direction, when the air temperature inside increases, the specific gravity of the air decreases and becomes lighter, and the light air floats smoothly. The chimney effect causes the air to float quickly in a space extending in the vertical direction like a chimney. In particular, the chimney effect can cause the internal air to float quickly in a restricted space that is not too wide, so a narrow cooling gap can be set between the busbar plate and the battery block to cause the internal air to float quickly. The ability to smoothly float the air in the narrow cooling gap to efficiently cool the battery cell has the following advantages: the battery system can be made compact while efficiently cooling the battery cell to suppress the temperature rise. In particular, the structure of dividing the cooling gap into a plurality of cooling ducts can suppress the temperature rise of the battery cell caused by each busbar plate in an ideal state.

[0041] It is further preferred that, in the chimney effect, the higher the temperature of the internal air is, the faster the internal air floats up. Therefore, the structure of dividing the cooling gap into a plurality of cooling ducts has the advantage of being able to suppress the temperature rise of each busbar plate and the temperature rise of the battery cells at the opposite position under an ideal state. In a battery block, when the load current increases, both the battery cells and the busbar plate generate heat due to Joule heat, thereby increasing the temperature. Therefore, it is extremely important to reduce the heat energy of the busbar plate with increased temperature to heat the battery cells. This is because the battery cells at the opposite position of the busbar plate generate heat due to the load current. Therefore, when they are further heated by the busbar plate with increased temperature in this state, the temperature rise is accelerated and the temperature rises significantly. In a battery system, the temperature rise of a specific battery cell becomes a disadvantage of the electrical characteristics of the entire battery system. For example, a deteriorated specific battery cell will shorten the life of the entire battery system and limit the maximum load current of the battery system.

[0042] The chimney effect of the cooling duct causes the temperature of both the bus plate and the battery cell to rise as the load current of the battery system increases, allowing the internal air to float up more quickly, which can effectively suppress the heat energy of the bus plate heating the battery cell. Therefore, in an operating environment where the temperature of the battery cell rises, the ideal advantage of being able to suppress the temperature rise of the battery cell caused by the bus plate is achieved.

[0043] Furthermore, the above advantage, namely, the better insulation effect obtained based on the chimney effect of the cooling duct, is particularly effective in a battery system in which the total current of multiple battery cells flows through a bus plate and the heat energy caused by the Joule heat of the bus plate is large. In an operating environment where the load current increases, the advantage of being able to more effectively suppress the temperature rise of the battery cells is achieved.

[0044] In another embodiment of the present invention, a battery holder of a battery system can be provided with a spacer protrusion protruding toward a surface opposite to a busbar plate, and the spacer protrusion abuts against the busbar plate to maintain the cooling gap at a fixed gap. The battery system has the advantage that the cooling gap can be maintained as a gap with excellent heat insulation effect by the spacer protrusion.

[0045] A storage battery system according to another embodiment of the present invention can arrange the spacer protrusion at the center of the busbar plate, so that the elongated busbar plate extending in the vertical direction can form a gap having an excellent heat insulating effect.

[0046] In a battery system according to another embodiment of the present invention, the spacer protrusion located at the center of the busbar plate can be set as a threaded protrusion integrally constructed with the battery holder, and the set screw that passes through the busbar plate is screwed into the threaded protrusion to fix the busbar plate to the battery holder. This battery system uses both the spacer protrusion that keeps the cooling gap at a fixed gap and the threaded protrusion that fixes the busbar plate to the battery holder, so it has the advantage that the set screw can pass through the busbar plate and be screwed into the threaded protrusion to fix the busbar plate to a fixed position of the battery holder, while keeping the cooling gap at a fixed gap.

[0047] A battery system according to another embodiment of the present invention can be provided with a convex spacer protrusion in a battery holder, and the spacer protrusion is arranged at the upper and lower parts of the inner side of the busbar plate and extends in the vertical direction. The battery system sets the cooling gap provided on the inner surface of the elongated busbar plate fixed to the battery holder as a fixed gap as a whole, and sets the spacer protrusion as a convex strip extending in the vertical direction, so that the air in the cooling gap floats smoothly, and has the advantage of being able to achieve an excellent heat insulation effect of the cooling gap as a whole.

[0048] A storage battery system in another embodiment of the present invention is capable of configuring a battery cell as a cylindrical battery, configuring a plurality of cylindrical batteries to extend in the up-down direction, configuring the two end surfaces of the cylindrical battery as the upper surface and the lower surface of the battery block, connecting the first lead plate to the upper surface electrode of the cylindrical battery, connecting the second lead plate to the lower surface electrode of the cylindrical battery, and connecting the plurality of cylindrical batteries in parallel via the lead plates.

[0049] [Implementation Method 1]

[0050] Figure 1 It is a perspective view in which the battery system 1 and the outer case 2 are separated. Figure 2 and Figure 3 is a perspective view of the battery system 1 viewed from opposite sides. Figure 4 This is a perspective view of the battery system 1 as viewed from below. Figure 5 is a perspective view showing a state where the busbar plate 3 of the battery system 1 is separated. Figure 6 is a vertical cross-sectional view showing a cooling gap 5 provided between the busbar plate 3 and the battery block 4, Figure 7 and Figure 8 is a horizontal cross-sectional view of the battery block 4, Figure 7 is a horizontal cross-sectional view of the upper part, Figure 8 It is a horizontal cross-sectional view of the central part.

[0051] The battery system 1 shown in the above figure comprises: a battery block 4 having a plurality of battery cells 4A; a plurality of first lead plates 7A arranged on the upper surface of the battery block 4 and connected to the end surface electrodes of the battery cells 4A; a plurality of second lead plates 7B arranged on the lower surface of the battery block 4 and connecting the battery cells 4A to the end surface electrodes; and a plurality of busbar plates 3 electrically connecting the upper and lower ends to the first lead plate 7A and the second lead plate 7B, which are themselves arranged on the side of the battery block 4 in a posture extending in the up and down direction.

[0052] (Battery Block 4)

[0053] Figures 1 to 4 The battery block 4 shown is generally shaped like a rectangular parallelepiped, with the first lead plates 7A arranged in multiple rows in parallel on the upper surface, and the second lead plates 7B arranged in multiple rows in parallel on the lower surface. The battery block 4 places all battery cells 4A in a parallel position, with the end electrodes arranged on the same plane. The battery block 4 connects multiple rows of battery cells 4A arranged on the same plane in parallel through the first lead plate 7A and the second lead plate 7B to form a parallel block 4Ap, arranges multiple parallel blocks 4Ap in multiple rows, and connects adjacent parallel blocks 4Ap in series through the busbar plate 3. Figures 1 to 4 The battery blocks 4 are arranged such that the battery cells 4A of the adjacent parallel blocks 4Ap are arranged between the valleys of the adjacent battery cells 4A, and the parallel blocks 4Ap are arranged close to each other. However, the present invention does not limit the state of arranging multiple parallel blocks into multiple rows to the state shown in the figure. For example, although not shown in the figure, the battery cells can also be arranged in a checkerboard pattern.

[0054] Fig. 9A circuit diagram is shown in which a battery cell 4A is connected to a first lead plate 7A and a second lead plate 7B via a busbar plate 3. The busbar plate 3 shown in the figure connects in series a parallel block 4Ap consisting of a plurality of battery cells 4A connected in parallel via the first lead plate 7A and the second lead plate 7B, so that the total current flowing through the battery cells 4A constituting the parallel block 4Ap flows. For example, the total current of the busbar plate 3 of the battery system 1 in which 10 battery cells 4A are connected in parallel is 10 times the current of the battery cells 4A. Figure 2 and Figure 3 The storage battery system 1 shown in the stereoscopic diagram of FIG. 1 connects the parallel blocks 4Ap in series through a pair of busbar plates 3 disposed on both side surfaces of the battery block 4, so that the current flowing through each busbar plate 3 can be reduced to 1 / 2 of the total current. However, although not shown in the figure, the storage battery system 1 can also connect the parallel blocks in series only through a busbar plate disposed on one side of the battery block without connecting the parallel blocks through a pair of busbar plates.

[0055] The battery block 4 includes a battery holder 4B for placing each battery cell 4A at a fixed position. The battery holder 4B is a molded body of an insulating material such as plastic, and includes an insertion tube 6 for inserting each battery cell 4A and placing the battery cell 4A at a fixed position. Figure 7 and Figure 8 In the battery holder 4B shown in the cross-sectional view of FIG. 8 , the surface of the insertion tube 6 facing the busbar plate 3 is formed as an insulating tube 6A, and a cooling gap 5 is provided between the insulating tube 6A and the busbar plate 3 .

[0056] (First Lead Plate 7A and Second Lead Plate 7B)

[0057] Figures 1 to 4 The battery system 1 shown in the figure electrically connects the first lead plate 7A to the end surface electrode at the upper end of the battery cell 4A arranged on the upper surface of the battery block 4, and electrically connects the second lead plate 7B to the end surface electrode at the lower end of the battery cell 4A arranged on the lower surface of the battery block 4. The first lead plate 7A and the second lead plate 7B are provided with a connecting arm portion 9 ( Figure 6 ), the connecting arm portion 9 is electrically connected to the end face electrode of the battery cell 4A by spot welding, laser welding or the like. The connecting arm portion 9 enables the welding area to protrude toward the end face electrode and be reliably welded to the end face electrode. The first lead plate 7A and the second lead plate 7B are conductive metal plates such as aluminum plates, nickel plates, and copper plates, and the connecting arm portion 9 is provided at a position opposite to the end face electrode of the battery cell 4A. The connecting arm portion 9 protruding toward the surface of the end face electrode and abutting against the surface of the end face electrode is reliably welded and electrically connected to the end face electrode by spot welding, laser welding or the like. The first lead plate 7A and the second lead plate 7B are provided with a bent connection portion 7C bent at 90 degrees at the end, which can be easily connected to the busbar plate 3.

[0058] The first lead plate 7A and the second lead plate 7B are elongated plates extending along the upper and lower surfaces of the parallel block 4Ap in which a plurality of battery cells 4A are arranged in a row, and a connecting arm portion 9 is provided at a position opposite to the end surface electrode of each battery cell 4A. The connecting arm portion 9 is connected to the end surface electrode of the battery cell 4A, and the first lead plate 7A and the second lead plate 7B connect the battery cells 4A constituting the parallel block 4Ap in parallel. The battery block 4 arranges a plurality of parallel blocks 4Ap in a plurality of rows, so that a plurality of rows of the first lead plates 7A are arranged in parallel on the upper surface of the battery block 4, and the second lead plates 7B are arranged in parallel on the lower surface of the battery block 4, and the respective battery cells 4A constituting the parallel block 4Ap are connected in parallel. The battery block 4 shown in the figure arranges a plurality of battery cells 4A in a row as a parallel block 4Ap, but although not shown in the figure, the battery block can also arrange the battery cells in a plurality of rows to constitute a parallel block.

[0059] Since the multiple columns of parallel blocks 4Ap are connected in series through the busbar plates 3, there is a potential difference between adjacent lead plates. Therefore, the lead plates 7 arranged in parallel with each other have an insulating gap between adjacent lead plates 7. When the lead plates 7 are connected to the end surface electrodes of the battery cells 4A constituting the parallel blocks 4Ap, the lateral width is such that an insulating gap 10 can be formed between the adjacent lead plates 4. The first lead plate 7A and the second lead plate 7B are connected to the end surface electrodes of the battery cells 4A and arranged at fixed positions, and an insulating gap 10 is provided between the adjacent lead plates.

[0060] The first lead plate 7A and the second lead plate 7B are provided with bent connection portions 7C at their ends, and can be simply, easily and reliably connected to the busbar plate 3. This is because the first lead plate 7A and the second lead plate 7B can be arranged on the upper and lower surfaces of the battery block 4, and the bent connection portions 7C can be in a vertical posture and surface-contacted with the upper and lower connection portions of the busbar plate 3 for connection.

[0061] (Bus plate 3)

[0062] The busbar plate 3 connects the upper and lower ends to the first lead plate 7A and the second lead plate 7B, and connects a plurality of parallel blocks 4Ap in series. The busbar plate 3 is a conductive elongated metal plate such as an aluminum plate, a nickel plate, or a copper plate, and is connected to the first lead plate 7A and the second lead plate 7B via a connecting lead. The total current of the parallel block 4Ap flows through the busbar plate 3, so a metal plate with a current capacity whose maximum current is greater than the total current of the parallel block 4Ap is set. Therefore, the busbar plate 3 made of the same metal material as the lead plate is made thicker than the lead plate, thereby reducing the resistance. The battery system 1 arranges the busbar plate 3 in a parallel posture on the side of the battery block 4, and connects the first lead plate 7A and the second lead plate 7B in series. Fig. 9The battery system 1 shown in the circuit diagram of FIG. 1 connects both ends of the first lead plate 7A and the second lead plate 7B in series through a pair of busbar plates 3. Figure 2 and Figure 3 As shown, the battery system 1 is provided with a pair of busbar plates 3 on both sides of the battery block 4, and the first lead plate 7A and the second lead plate 7B are connected in series through each busbar plate 3. The upper and lower ends of the busbar plate 3 are connected to the lead plates of the adjacent parallel block 4Ap, and the adjacent multiple columns of parallel blocks 4Ap are connected in series. The busbar plate 3 shown in the above figure makes the upper end connection part and the lower end connection part in a vertical posture, makes the upper end connection part and the lower end connection part in an inclined posture, and connects the upper end connection part and the lower end connection part to the first lead plate 7A and the second lead plate 7B of the adjacent parallel block 4Ap.

[0063] Figure 5 The busbar plate 3 shown connects the parallel blocks 4Ap in series, and a cooling gap 5 is provided between the busbar plates 3 and the battery blocks 4. Since a potential difference is generated between adjacent busbar plates 3, a plurality of rows of busbar plates 3 are arranged in a parallel posture on the same plane, and an insulating gap 10 is provided between adjacent busbar plates 3. The insulating gap 10 is provided with an insulating ridge 11, and the adjacent busbar plates 3 are insulated by the insulating ridge 11. The insulating ridge 11 is formed into an integral structure with the plastic molded body of the insulating material, that is, the battery holder 4B, and is arranged at a fixed position and arranged at the position of the insulating gap 10 of the adjacent busbar plates 3. The insulating ridge 11 is a ridge extending in the vertical direction along the insulating gap 10 between the adjacent busbar plates 3, and is preferably set to a height protruding from the insulating gap 10 to the surface of the busbar plate 3, so that the busbar plate 3 can be reliably insulated. The insulating ridges 11 not only play a role of insulating the adjacent busbar plates 3, but also serve as partition walls for dividing the cooling gaps 5 inside each busbar plate 3 into cooling ducts 5A having a predetermined lateral width.

[0064] In the battery holder 4B, the first lead plate 7A and the second lead plate 7B are also provided with an insulating gap 10 between adjacent lead plates, and an insulating ridge 11 protruding toward the insulating gap 10 is provided as an integral structure. The insulating ridge 11 is arranged in the gap between adjacent lead plates similarly to the insulating ridge 11 that insulates the busbar plate 3, and insulates the adjacent lead plates.

[0065] (Cooling gap 5)

[0066] Figures 6 to 8The battery system 1 shown is provided with a cooling gap 5 for suppressing the temperature rise of the battery cell 4A caused by the busbar plate 3 whose temperature rises. The cooling gap 5 is provided between each busbar plate 3 arranged in multiple rows and the battery block 4. The cooling gap 5 is a gap extending in the up-down direction between the multiple rows of busbar plates 3 and the battery block 4, and the internal air is floated by the chimney effect to achieve an excellent heat insulation effect. When the internal air of the cooling gap 5 floats, the floating internal air is discharged from the gap in the upper part of the cooling gap 5, and the air with a lower temperature flows in from the gap in the lower part of the cooling gap 5, so that the heat insulation effect of the cooling gap 5 is improved. The cooling gap 5 is provided so that the multiple rows of busbar plates 3 are separated from the side of the battery block 4, so as long as a seal or gasket is not used to form a completely airtight structure, a gap can be formed for the internal air to ventilate the upper and lower parts. Therefore, the cooling gap 5 is a closed but not airtight space.

[0067] The so-called chimney effect refers to the effect that the high-temperature internal air in the chimney is quickly discharged. It has the effect that in the chimney extending in the up-down direction, the specific gravity of the high-temperature internal air becomes lighter and it quickly floats up and is discharged. The chimney uses this effect to quickly discharge the high-temperature internal air. The chimney effect can quickly discharge the high-temperature internal air in a restricted space extending in the up-down direction like a chimney, so the cooling gap 5 can be set to a narrow gap to make the internal air float up quickly to improve the thermal insulation effect. Therefore, a narrow cooling gap 5 of, for example, 1 to 5 mm is provided between the busbar plate 3 and the battery block 4, and the internal air is heated by the busbar plate 3 to make it float up quickly, which can improve the thermal insulation effect.

[0068] More advantageously, the cooling gap 5 that improves the heat insulation effect by the chimney effect realizes the excellent advantage of being able to quickly float the internal air as the temperature of the busbar plate 3 increases to improve the heat insulation effect. When the load current of the battery system 1 increases and the temperature rise of both the busbar plate 3 and the battery cell 4A is large, the cooling gap 5 is required to have excellent heat resistance. In the battery system 1, when the load current increases, the temperature rise of the busbar plate 3 and the battery cell 4A also increases. This is because the busbar plate 3 and the battery cell 4A generate heat due to the Joule heat of the current flowing therethrough. Therefore, when the load current increases and the temperature of the busbar plate 3 and the battery cell 4A increases, the battery system 1 requires excellent heat resistance for the cooling gap 5. The cooling gap 5 that can quickly float the internal air to improve the heat insulation effect by the chimney effect realizes the ideal characteristic that the higher the temperature rise of the busbar plate 3, the faster the internal air of the busbar plate 3 can float to improve the heat insulation effect. Furthermore, the cooling gap 5 is preferably narrow and allows the internal air to quickly rise, so that the temperature rise of the battery cells 4A can be effectively suppressed while the outer shape of the battery system 1 is slightly increased.

[0069] Figure 5 The battery system 1 shown is provided with an insulating gap 10 between a plurality of busbar plates 3 arranged on the same plane, and an insulating ridge 11 integrally constructed with the battery holder 4B is arranged in the insulating gap 10. The insulating ridge 11 also serves as a partition wall that insulates the adjacent busbar plates 3 and divides the cooling gap 5 into a plurality of cooling ducts 5A extending in the vertical direction. The cooling gap 5 divided into a plurality of cooling ducts 5A allows the internal air to float more efficiently through the chimney effect of each cooling duct 5A, thereby improving the heat insulation effect. The chimney effect of the cooling duct 5A allows the internal air to float quickly in a limited space that is not too wide, so a narrow cooling gap 5 is provided between the busbar plate 3 and the battery block 4, and the cooling gap 5 is further divided into a plurality of cooling ducts 5A, thereby allowing the internal air of the cooling gap 5 to float quickly to improve the heat insulation effect. The fact that the air can float smoothly through the narrow cooling gap 5 to efficiently cool the battery cell 4A allows the battery system 1 to be compact while efficiently cooling the battery cell 4A. Furthermore, by providing the insulating ridges 11 for insulating the busbar plates 3 , although the internal volume of the cooling gaps 5 is slightly reduced, the cooling gaps 5 can achieve excellent heat insulation effects and ideally suppress the temperature increase of the battery cells 4A caused by the busbar plates 3 having increased temperatures.

[0070] Figure 7The horizontal cross section of the upper part of the battery block 4 is shown, but the battery system 1 is provided with a slit-shaped ventilation gap between the two side edges of the busbar plate 3 and the insulating ridges 11. Although not shown in the figure, the busbar plate 3 is also provided with a slit-shaped ventilation gap between the two side edges and the insulating ridges 11 at the lower part. The slit-shaped ventilation gap discharges the floating air to the outside at the upper part of the cooling duct 5A, and the air outside the cooling duct 5A whose temperature has not risen flows into the lower part. Furthermore, as mentioned above, the first lead plate 7A and the second lead plate 7B are also provided with a slit-shaped ventilation gap between their two side edges and the insulating ridges 11, so the air in the cooling duct 5A is also ventilated from the gap.

[0071] Preferably, for the chimney effect, the higher the internal air temperature is, the faster the internal air rises. Therefore, the structure of dividing the cooling gap 5 into a plurality of cooling ducts 5A has the following advantages: the temperature rise of each busbar plate 3 can be suppressed in an ideal state, and the temperature of the battery cell 4A at the opposite position can be raised. In the battery block 4, when the load current increases, both the battery cell 4A and the busbar plate 3 are heated by Joule heat and the temperature rises. Therefore, it is extremely important to reduce the heat energy of the busbar plate 3 with the increased temperature to heat the battery cell 4A. This is because the battery cell 4A located at the opposite position of the busbar plate 3 generates heat due to the load current. Therefore, when it is further heated by the busbar plate 3 with the increased temperature in this state, the temperature rise is accelerated and the temperature rises significantly. In the battery system 1, the temperature rise of a specific battery cell 4A becomes a disadvantage of the electrical characteristics of the entire battery system 1. For example, the deteriorated specific battery cell 4A will shorten the life of the entire battery system 1 and limit the maximum load current of the battery system 1.

[0072] The chimney effect of the cooling duct 5A causes the internal air to float up more quickly as the load current of the battery system 1 increases, thereby increasing the temperature of both the bus plate 3 and the battery cell 4A. This can effectively suppress the heat energy of the bus plate 3 that heats the battery cell 4A. Therefore, in an operating environment where the temperature of the battery cell 4A increases, the ideal advantage of being able to suppress the temperature increase of the battery cell 4A caused by the bus plate 3 is achieved.

[0073] Furthermore, the above advantage, i.e., the better insulation effect achieved by the chimney effect of the cooling duct 5A, is particularly effective in a battery system 1 in which the total current of multiple battery cells 4A flows through the bus plate 3 and the heat energy caused by the Joule heat of the bus plate 3 is large, and in an operating environment where the load current increases, the advantage of being able to more effectively suppress the temperature rise of the battery cells 4A is achieved.

[0074] Further, Figure 7 and Figure 8The storage battery system 1 shown in the horizontal cross-sectional view is provided with an insulating tube portion 6A of the battery holder 4B between the cooling gap 5 and the battery cell 4A, which more effectively suppresses the temperature rise of the battery cell 4A caused by the busbar plate 3. The battery holder 4B can prevent the disadvantage that the temperature of the battery cell 4A rises due to the radiant heat of the busbar plate 3, thereby suppressing the temperature rise of the battery cell 4A. More preferably, the radiant heat of the busbar plate 3 irradiates the surface of the battery holder 4B opposite to the busbar plate 3, so that the temperature of the surface of the battery holder 4B opposite to the busbar plate 3 irradiated by the radiant heat rises, and this temperature rise promotes the floating of the internal air, thereby improving the heat insulation effect of the cooling gap 5 based on the chimney effect. The structure of suppressing the temperature rise of the battery cell 4A by the two-layer heat insulation structure of the cooling gap 5 and the battery holder 4B does not simply stop at preventing the bus bar plate 3 from causing the battery cell 4A temperature to rise due to radiation heat. In addition to suppressing the temperature rise of the battery cell 4A caused by radiation heat, it also achieves the following advantages: by using radiation heat to increase the temperature of the opposite surface of the battery holder 4B, the actual heat insulation effect between the bus bar plate 3 and the battery cell 4A can be further improved. Therefore, the above battery system 1 has the advantage of being able to more effectively suppress the temperature rise of the battery cell 4A through the synergistic effect of the cooling gap 5 and the battery holder 4B.

[0075] Figure 5 The stereogram and Figure 8 The battery holder 4B shown in the horizontal cross-sectional view is provided with a spacer protrusion 12 protruding toward the surface facing the busbar plate 3 to maintain the cooling gap 5 at a fixed gap. The busbar plate 3 abuts against the spacer protrusion 12 to maintain the cooling gap 5 at a fixed gap. Figure 5 The battery system 1 has the spacer protrusion 12 located in the central portion of the busbar plate 3, and a cooling gap 5 with a fixed gap is provided on the inner side of the elongated busbar plate 3. Furthermore, the battery system 1 of the figure has the spacer protrusion 12 configured as a threaded protrusion 12A integrally constructed with the battery holder 4B, and the busbar plate 3 is fixed with a set screw 13. The set screw 13 passes through the busbar plate 3 and is screwed into the threaded protrusion 12A, thereby fixing the busbar plate 3 to the threaded protrusion 12A of the spacer protrusion 12. This structure configures the spacer protrusion 12 with the cooling gap 5 as a fixed gap as the threaded protrusion 12A that fixes the busbar plate 3, thereby being able to provide a cooling gap 5 with a fixed gap on the inner surface of the busbar plate 3, and reliably fix the busbar plate 3 to the battery holder 4B. Furthermore, Figure 5 The illustrated battery holder 4B is also provided with spacer protrusions 12 having protrusions 12B extending in the vertical direction at the upper and lower portions inside the busbar plate 3 .

[0076] The battery system 1 described above can provide cooling gaps 5 having a high heat insulation effect at fixed intervals inside the entire elongated busbar plate 3 fixed to the battery holder 4B by screwing the set screw 13 into the threaded protrusion 12A. Furthermore, since the spacer protrusions 12 arranged at the upper and lower parts of the busbar plate 3 are provided as convex strips 12B extending in the vertical direction, the spacer protrusions 12 do not hinder the buoyancy of the air, so that the air floats smoothly along the spacer protrusions 12, which has the advantage of being able to achieve an excellent heat insulation effect through the entire cooling gap 5.

[0077] Industrial Applicability

[0078] The present invention can be effectively used for a battery system that reduces the temperature difference between a plurality of battery cells and a product equipped with the battery system.

[0079] -Explanation of symbols-

[0080] 1…Battery system

[0081] 2…External housing

[0082] 3…Busbar plate

[0083] 4…Battery blocks

[0084] 4A...Battery cell

[0085] 4B…Battery holder

[0086] 4Ap…Parallel Block

[0087] 5…Cooling gap

[0088] 5A...Cooling pipe

[0089] 6…Insert the barrel

[0090] 6A…Insulation tube

[0091] 7…Lead plate

[0092] 7A…1st lead plate

[0093] 7B…2nd lead plate

[0094] 7C…Bending connection

[0095] 9…Connecting arm

[0096] 10…Insulation clearance

[0097] 11…Insulation ribs

[0098] 12...Spacer protrusion

[0099] 12A…Threaded protrusion

[0100] 12B…convex strip

[0101] 13…Set screw

[0102] 901…Battery system

[0103] 903…Busbar Plate

[0104] 904A…Battery Cell

[0105] 904Ap…Parallel block.

Claims

1. A battery system comprising: A battery block having a plurality of battery cells; A plurality of first lead plates, arranged on the upper surface of the battery block and connected to the end surface electrodes of the battery cells; a plurality of second lead plates disposed on the lower surface of the battery block and connecting the battery cells to the end surface electrodes; and A plurality of busbar plates electrically connect upper and lower ends to the first lead plate and the second lead plate, and are arranged on the side of the battery block in a posture extending in the vertical direction. A cooling gap having air permeability and extending in the up-down direction is provided between the busbar plate and the battery block.

2. The battery system according to claim 1, wherein: The battery block comprises: A plurality of parallel blocks are formed by connecting a plurality of the battery cells in parallel via the first lead plate and the second lead plate. The busbar plate connects the parallel blocks in series.

3. The battery system according to claim 1, wherein: The battery block comprises: A battery holder is used to place the battery cell in a fixed position. The cooling gap is provided between the battery holder and the busbar plate.

4. The battery system according to claim 3, wherein: The plurality of busbar plates are arranged in parallel on the same plane. An insulating gap is provided between adjacent busbar plates. An insulating convex strip integrally constructed with the battery holder is arranged in the insulating gap. The insulating ridges divide the cooling gap into a plurality of rows of cooling pipes extending in the up-down direction.

5. The battery system according to claim 3, wherein: The battery holder has: The spacer protrusion protrudes toward the surface facing the busbar plate, The spacer protrusion abuts against the busbar plate to maintain the cooling gap at a fixed gap.

6. The battery system according to claim 5, wherein: The spacer protrusion is located at a central portion of the busbar plate.

7. The battery system according to claim 6, wherein: The spacer protrusion located at the center of the busbar plate is a threaded protrusion integrally constructed with the battery holder, A set screw that passes through the busbar plate is screwed into the threaded protrusion, thereby fixing the busbar plate to the battery holder.

8. The battery system according to claim 5, wherein: The battery holder has the spacer protrusions which are convex strips extending in the up-down direction at the upper and lower parts inside the busbar plate.

9. The battery system according to any one of claims 1 to 8, wherein: The battery cell is a cylindrical battery. The battery block has the following structure: The plurality of battery cells are arranged to extend in the vertical direction. The two end surfaces of the battery cell are configured as the upper surface and the lower surface of the battery block, The first lead plate is connected to the upper surface electrode of the battery cell. The second lead plate is connected to the lower surface electrode of the battery cell. The lead plate connects the plurality of battery cells in parallel.

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