JP7099807B2 - Battery pack - Google Patents

Description

The present invention relates to a battery pack.

Against the background of environmental problems and resource depletion problems, there is a need to develop energy-saving products with low environmental impact for the conservation of the global environment. As one of the products that can reduce the amount of CO ₂ , attention is focused on hybrid electric vehicles and eco-cars represented by electric vehicles, and the number of vehicles sold is increasing. Demand for in-vehicle secondary batteries installed in these eco-cars is also increasing. Examples of in-vehicle secondary batteries include lithium ion secondary batteries, lead storage batteries, nickel-metal hydride batteries, and the like. Among these, lithium-ion secondary batteries generally have a higher discharge potential than lead-acid batteries and nickel-metal hydride batteries, so that they can be made smaller and have higher energy densities, and are considered promising.

For example, the points required for a lithium ion secondary battery for full-scale application include further increase in energy density, higher output density, and longer life. In order to increase the output of the battery, it is effective to input / output a large current from the battery together with increasing the potential. However, when a large current is input / output from the battery, heat generation due to the internal resistance of the battery is generated inside the battery. If the generated heat cannot be sufficiently removed from the battery, the battery temperature will rise. Battery characteristics such as battery capacity and internal resistance of a lithium-ion battery differ in deterioration tendency depending on the battery temperature. In particular, the higher the battery temperature, the more the battery deteriorates, and in many cases, the capacity decreases and the internal resistance increases. Therefore, it is necessary to develop a technique for improving the heat dissipation performance of the battery.

When a plurality of lithium-ion batteries (hereinafter referred to as batteries) are combined and used as a battery group (for example, when used as a battery module or a battery pack), the temperature difference between the batteries in the battery group is small. Furthermore, it is desired that the maximum reaching temperature of the batteries existing in the battery group is low. This is because when the temperature difference between the cells is large and the maximum temperature reached is high, the difference in deterioration is likely to occur between the cells. Since the characteristics of the battery group tend to be rate-determined by the characteristics of the most deteriorated battery among the single batteries included in the battery group, it is necessary to design a battery group in which a specific battery does not deteriorate.

Therefore, various battery arrangement configurations have been developed in a battery group formed by combining a plurality of cells. For example, Patent Document 1 describes a configuration in which two battery groups in which five batteries are stacked in a direction substantially perpendicular to the wide surface of the cells are arranged side by side on a plate constituting the bottom surface of the housing. Has been done. Generally, the same current value is applied to batteries connected in series, so if the batteries have substantially the same internal resistance, the temperature of the batteries will be about the same. In this case, since heat flow between batteries is unlikely to occur, the larger the number of stacked batteries, the closer the temperature of the central portion of the stacked batteries approaches to the heat insulating state, and the higher the temperature is compared to the end portion of the battery group. It has been known. When the battery group in series is divided into two rows as in Patent Document 1, the battery group has the same configuration as five batteries stacked when viewed from the bottom of the housing, and therefore the central portion of the battery group. There is a merit that the temperature of the battery tends to drop. In addition, since the series batteries are separated, it is possible to reduce the height.

US Pat. No. 9,406,916

When the side surfaces of the battery groups are thermally and physically connected and arranged as in the structure described in Patent Document 1, the path for heat to escape from the connection surface of the battery groups is sandwiched between the battery groups. It is necessary to dissipate heat via the member and the housing in front of the member, which causes a problem that the heat dissipation path becomes redundant. When the heat dissipation path becomes redundant, the thermal resistance tends to be high, and there is room for improvement in order to improve the heat dissipation.

In such a configuration, when the cooling efficiency is lowered (for example, when the flow rate of the forced flowing air is small or when the input / output current is large and the calorific value of the single battery is large), the battery temperature in the configured battery group is adjusted. Distribution occurs, and in particular, among the battery groups stacked in the battery group, the battery temperature of the single battery arranged near the center is high, and deterioration may progress. The present invention has been made in view of the above problems, and an object of the present invention is to provide a battery pack having a small temperature difference between battery groups.

The battery pack according to the present invention is a battery cell including a pair of wide side surfaces, a pair of narrow side surfaces, a bottom surface connecting the wide side surfaces and the narrow side surfaces, and an upper surface on which external terminals are arranged. The first battery group in which the wide side surfaces of the battery cells are opposed to each other and a plurality of stacked batteries are provided, the second battery group in which the wide side surfaces of the battery cells are opposed to each other and the plurality of stacked batteries are stacked, and the first battery group. A surface including a housing for accommodating one battery group and a second battery group, a surface on which an external terminal of the first battery group is arranged, and a surface on which an external terminal of the second battery group is arranged. Are placed facing each other.

According to the present invention, the surfaces of the battery groups in which the external terminals are arranged face each other in the housing, and the battery groups are not thermally physically connected to each other, thereby reducing the thermal resistance of the battery groups. This can be reduced, thereby reducing the temperature of the cells in the battery group.

The figure for demonstrating an example of the specific structure of the battery group in Examples 1 and 2. The figure for demonstrating an example of a specific wiring configuration which is carried out in the case of electrically connecting the cell | cell which exists inside the battery group facing each other in the 1st and 2nd Examples. An exploded perspective view for explaining an example of a specific configuration of a battery module, which is carried out when the battery groups in the first embodiment are arranged facing each other in the housing. A plan view of the battery module shown in FIG. 3 when the lid is removed and the inside of the module is viewed from the upper surface of the lid. An exploded plan view of a portion in which the support base and electrical components shown in FIG. 4 are integrated. The figure for demonstrating an example of the specific structure of the battery group in Example 3. The figure for demonstrating an example of the specific structure of the battery group in Example 4. In order to explain an example of a specific battery module configuration to be carried out when the battery groups in the fifth embodiment are arranged facing each other in the housing, a plan view when the lid is removed and viewed from the upper surface thereof. The figure for demonstrating an example of the specific structure of the battery group in the comparative example 1. The figure for demonstrating an example of the specific structure of the battery group in the comparative examples 2 and 3. The figure which compares the temperature rise ratio of the battery group in Example 1 and Comparative Example 1 and Comparative Example 2. The figure which compares the temperature rise ratio of the battery group in Example 2 and the comparative example 3. FIG.

A mode for carrying out the present invention will be described. However, the present embodiment is not limited to the following contents, and can be arbitrarily modified and implemented without departing from the gist of the present invention. Further, the cooling environment in the present invention is an example, and can be applied even when other refrigerants other than air and water are used.

Although the lithium ion secondary battery is exemplified as the secondary battery in the present invention, the present configuration can be applied to other types of storage batteries. Further, the effect can be obtained regardless of the constituent members of the lithium ion secondary battery. That is, in the present invention, an electrode made of an Al collector foil and a positive electrode material having a layered structure is used as the positive electrode, and an electrode made of a Cu current collector foil and a carbon material is used as the negative electrode, but other configurations may be used. For example, even when an Al foil is used as the current collector foil of the negative electrode, it is possible to improve the heat dissipation. Further, although a square battery is used as the shape of the lithium ion battery in this embodiment, the effect can be obtained by using other shapes such as a laminated type battery and a cylindrical type battery.

As for the number of battery groups included in the housing, as in the configuration in the present invention, the side surface of the battery physically and thermally contacts the side surface of the housing, so that the heat dissipation path from the side surface of the battery group can be obtained. It may be any number as long as it can be shortened, but an even number is preferable to ensure the stability of the battery pack. For example, when there are two battery groups as in the embodiment of the present invention, the battery groups can be physically and thermally contacted with the left and right side surfaces of the housing.

Further, the number of batteries constituting the battery group can be the configuration of the present invention, and the effect of the present invention can be obtained as long as the number of batteries can be accommodated in the housing and a desired voltage and capacity can be secured. As for the heat dissipation effect, the smaller the number of stacked batteries in one battery group, the more effective it is, but it is preferably 100 or less, more preferably 20 or less, and most preferably 10 or less. As in the embodiment of the present invention, the number of batteries can be reduced to six, so that the battery pack can be compact and has cooling properties.

Further, the effect in the present invention can be obtained even if the number of batteries facing each other is not necessarily the same. For example, the effect of the present invention can be obtained even when the number of batteries in one of the battery groups is one or more larger than the number of batteries in the other.

Further, the effect of the present invention can be obtained even if an insulating sheet or a member having high thermal conductivity is arranged between the cells forming the battery group, and the effect of the present invention can be obtained even if the insulating sheet or a member having high thermal conductivity is not arranged. Further, the effect in the present invention can be obtained even if a three-dimensional structure such as protrusions or grooves having various shapes such as rails or dots is introduced into the insulating sheet or the member having high thermal conductivity. When the side surface of the cell is covered with an insulating material, a material having high thermal conductivity such as aluminum, aluminum die casting, copper, and iron can be used as the material for these members. When the side surface of the cell is not coated with an insulating material, polypropylene, polyamide, polyetherimide, PPS, PPA, PBT or the like or a highly thermally conductive resin can be used.

In the present invention, the battery groups are arranged to face each other inside the housing, and the electrode surfaces face each other. Therefore, in order to ensure crushing safety, the battery groups facing each other are insulated from each other. It is preferable to arrange at least a part of the sex member. Examples of the members include the following.

It is a support base created by using an insulating member as at least a part of the constituent members, and the support base includes a battery safety mechanism (for example, a fuse) and a control device (for example, a Battery Management System: BMS). It may be provided with at least one of electrical components such as relays, shunt resistors, and conductive wiring such as bus bars and conductors required for precharging. In addition, the support may be provided with screws, screw holes, or fixing devices capable of fixing these electrical components. By integrating the above-mentioned electrical components with the support base using these fixing devices, it is possible to connect the electrical components such as safety mechanisms and the battery group via conductive wiring and electrically connect to the external terminals. can. As a result, an insulating member can be introduced between the terminal surfaces of each battery group, so that the battery pack can be made into a battery pack having high heat dissipation while having crushing safety.

Further, the present invention is not particularly limited in terms of the method and positional relationship of attaching a safety mechanism or the like to these supports. For example, these devices may be arranged / built in the upper / lower surface, the side surface, or the inside of the insulating support base. Further, the order of electrical arrangement of these devices is not particularly limited. Further, the size and shape of the support base may be any size and shape as long as the insulation between the two battery groups can be ensured when the battery groups approach each other due to crushing. For example, the support base may be in the shape of a thin plate, or may have a complicated three-dimensional shape for storing each electrical component as in the support base exemplified in the present invention.

If the battery group is arranged as in the present invention, the effect in the present invention can be obtained regardless of how the cells constituting the battery group are electrically connected to each other. For example, the effect of the present invention can be obtained even if the battery groups are connected in parallel by devising wiring. Here, as an example, a case where a single battery in a battery group is connected in series and two opposing battery groups are also connected in series will be described.

Examples of the method of connecting the battery groups in series after making the battery groups face each other include the following.
(A) A method of directly connecting battery groups using a bus bar. At this time, in consideration of workability, the bus bars may be electrically connected to each other by using a bus bar extended for connection or a part of the wiring, and using a method such as screwing or welding. However, the method of electrically connecting is not limited to these.
(B) The above-mentioned method of electrically connecting bus bars to each other via a support base including an insulating member as a constituent member. At this time, it is preferable to incorporate conductive portions such as bus bars or cables in the support base and electrically connect them via the conductive members thereof.
(C) A method of directly connecting battery groups using a cable.
(D) Examples thereof include the method of electrically connecting cables to each other via a support base including an insulating member as a constituent member.

Further, in the battery group, in addition to electrically connecting the cells in series or in parallel, it is preferable to physically restrain the cells by using a fixing jig. When the side surface of the cell is covered with an insulating material, a material having high thermal conductivity such as aluminum, aluminum die cast, copper, and iron can be used as the material of the fixing jig. When the side surface of the cell is not coated with an insulating material, polypropylene, polyamide, polyetherimide, PPS, PPA, PBT or the like or a highly thermally conductive resin can be used. Further, the present invention is not limited to the method of restraint. For example, the effect was exhibited whether the two battery groups were bound using one set of fixing jigs or fixed using two sets of fixing jigs. Further, the effect in the present invention was obtained even if at least a part of the fixing jig was a housing.

The contact method between the housing and each member such as the battery group and the support base is not particularly limited, and the effect in the present invention can be obtained by, for example, bonding with an adhesive or connecting via a fixing device such as a bolt or a nut. The shape of the housing exemplifies a rectangular cuboid in the present embodiment, but the shape is not particularly limited. Further, the effect in the present invention is not limited to the current application condition and the cooling condition to the battery pack.

Since a bus bar and a conducting wire having good thermal conductivity are arranged on the support base exemplified in the present invention, a cooling effect can be expected when a mechanism for releasing heat from the support base is provided. For example, a cooling mechanism such as a heat pipe or a cooling pipe may be provided at a portion that is in thermal contact with the support base.

Further, even if the housing is provided with a cooling mechanism such as a jacket or piping using fins or other refrigerants, the effect can be obtained by adopting the structure according to the present invention.

Examples of the type of the housing include a resin housing and a metal housing, but the housing is not particularly limited. It is preferable that the housing is made of a heat conductive metal such as aluminum, aluminum die-cast, copper, or iron.

In the example of the present invention, the position of the external terminal appearing from the lid is arranged in the upper part of the space where the electrical component can be arranged, but the position of the external terminal can be arranged in the upper part of the pressurizing binding jig. In this case as well, the effect of the present invention can be obtained by adopting the structure of the present invention. In the embodiment, a conducting wire such as a bus bar is arranged with respect to a support base including an insulating member as a constituent member, and various electrical components are connected to the support wire by using screws to electrically connect them. The method is illustrated.

(Example 1)
Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples.

First, the outline of the battery pack 100 according to the present invention will be described with reference to FIG. FIG. 3 is an exploded perspective view of the battery pack 100 of the present invention. The battery pack 100 according to the present invention is illustrated in FIG. 3, a metal housing 7 for accommodating two battery groups 10A and 10B, the two battery groups 10A and 10B, a lid 8 for closing the opening of the housing 7, and FIG. It is composed of a support base 4 on which an electric component that has not been installed is arranged. The support base 4 is arranged in the electrical component placement space 4A between the battery group 10A and the battery group 10B. The battery groups 10A and 10B are arranged so that the terminals of the cell 1 (positive electrode terminal 12, negative electrode terminal 13) face each other, and are electrically connected to each other by wiring 6. An external terminal 9 is arranged on the lid 8 and is electrically connected to the wiring 6, so that electric power can be taken out from the battery pack 100 via the external terminal 9.

Details of the battery groups 10A and 10B will be described with reference to FIG. The cell 1 is composed of a pair of wide surfaces, a pair of narrow surfaces, a bottom surface, and an upper surface, and a positive electrode terminal 12 and a negative electrode terminal 13 are arranged on the upper surface. Insulating spacers 11 are arranged between the cells 1, and the cells 1 are laminated so that the positive and negative electrodes of the terminals are staggered.

A pair of pressurizing binding jigs 3 are arranged facing each of the wide surface of the cell 1 arranged at the uppermost portion and the wide surface of the cell 1 arranged at the lowermost portion.

Further, a pair of pressurizing binding jigs 2 are arranged facing the narrow side surface of the cell 1, and the pressurizing binding jig 2 and the pressurizing binding jig 3 are fixed to each other by the fixing metal fittings 5. ing.

Subsequently, FIG. 2 shows the connection between the wiring 6 and each cell 1. The wiring 6 is divided into three types: a wiring 6A connected to the external terminal 9, a wiring 6C connecting the cells 1 to each other, and a wiring 6B connecting the battery groups 10A and 10B. These wirings 6A, 6B, and 6C are connected to form a battery group 10A and a battery group 10B. The wiring 6B of the battery group 10A and the wiring 6B of the battery group 10B are connected to each other.

Subsequently, FIG. 4 shows a view seen from the opening side of the housing 7 with the lid 8 of FIG. 3 removed. The support 4 arranged between the first battery group 10A and the second battery group 10B is connected to the wiring 6A, and the wiring 6A is connected to the external terminal 9 provided on the lid 8. It is electrically connected to the portion 6A1. A BMS (board) 20, a shunt resistor 21, a fuse 22, and a relay 23 are assembled to the support base 4. The assembly method will be described in detail with reference to FIG. An insulating member is used for this support base, and for example, an insulating resin material is used.

Subsequently, the support base 4 will be described with reference to FIG. The BMS 20 and the shunt resistor 21 are arranged on one surface of the support base 4, and the fuse 22 and the relay 23 are arranged on the other surface. The BMS 20 and the shunt resistor 21 are integrally assembled, and one side is connected to the wiring 6A and the other side is connected to the support base terminal portion 6A1.

Since the fuse 22 and the relay 23 arranged on the other surface are large parts, two recesses are provided on the other surface, and the fuse 22 and the relay 23 are housed therein. With such a structure, the integrated assembly of the support base 4 and the electrical components can be made smaller. The fuse 22 and the relay 23 may be connected to each other by the connection wiring 6A2 to be integrated, and then assembled to the support base 4. Further, when assembling electrical components, parts such as screws are used for assembling, but the assembling method is not limited to that.

Subsequently, the feature portion of the present embodiment will be described again with reference to FIG.

In this embodiment, the four surfaces of the battery groups 10A and 10B, that is, the two sides of the battery groups 10A and 10B (the surfaces on which the pressurizing binding jig 2 is arranged), the bottom surface of the cell 1 and the battery group 10A, The lowermost surface of the 10B (the lower surface on which the pressurizing binding jig 3 is arranged) is housed in the housing 7 so as to be in direct contact with the housing. Therefore, the cooling property is most improved when two or more battery groups 10A and 10B are stored. On the other hand, in order to improve the cooling efficiency, it is necessary to store the surface on which the terminals of the battery group 10A are arranged and the surface on which the terminals of the battery group 10B are arranged so as to face each other. Therefore, in the present invention, the electrical components required for the battery pack 100 are assembled on the insulating support base and arranged between the battery group 10A and the battery group 10B. Therefore, while improving the cooling performance of the battery pack 100, the insulation between the two battery groups 10A and the battery group 10B can be ensured, and the size of the battery pack 100 can be prevented from becoming large. The point that the size of the battery pack 100 can be prevented from becoming large will be described in more detail. Originally, if the terminal side surface of the battery group 10A and the terminal side surface of the battery group 10B are to face each other, it is necessary to increase the creepage distance for the two battery groups, and the volume of the battery pack 100 increases by that amount. Therefore, since the space for gaining the creepage distance of the battery groups 10A and 10B can be overlapped with the space in which the support base is arranged, it is possible to prevent the battery pack 100 from becoming large.

As a further effect of this structure, the battery pack 100 is configured after the electrical components are once integrated with the support base 4. Therefore, the work can be completed by fixing the support base 4 to which the electrical components are fixed to the housing 7 or the like at once without arranging the electrical components in the narrow space between the battery group 10A and the battery group 10B. Workability when creating the battery pack 100 is improved.

Further, in this embodiment, a substrate (20) is arranged on one side of the support base 4, and a relay (23) and a fuse (22), which are large parts, are arranged on the other side. With such a structure, the BMS 20 which is a flat member can be arranged on one side, which is wasteful as compared with a structure in which the relay 23 is arranged on one side of the support base 4 and the fuse 22 is arranged on the other side. No uneven space is generated. Therefore, it contributes to miniaturization.

In this embodiment, the bus bar is used as the wiring 6, but a cable may be used.

A current was applied to the battery pack produced as described above. At this time, a member having a low thermal conductivity was placed on the lower surface of the housing, and a current was applied to obtain the test results in a constant temperature bath with substantially no air flow. The amount of heat generated from the battery was calculated from the current value, and the current value was applied so that the average was 3 W. In this embodiment, FIG. 11 shows the temperature behavior when the battery pack is in a nearly steady state after the above conditions are applied to the battery pack.

(Example 2)
In this embodiment, an electrode made of an Al collector foil and a positive electrode material having a layered structure is used as a positive electrode, and an electrode made of an Al collector foil and a spinel-based oxide is used as a negative electrode, and these electrodes are simply wound around. A group of batteries was obtained by stacking six batteries as shown in FIG. 1 and fixing the periphery thereof using a pressurizing jig for fixing. In this embodiment, the same current application conditions as in the first embodiment and the surrounding cooling environment are applied to the battery having the above configuration, and the results when the battery is in a substantially steady state are shown in FIG.

(Comparative Example 1)
An electrode made of an Al collector foil and a positive electrode material having a layered structure is used as a positive electrode, and an electrode made of a Cu current collector foil and a carbon material is used as a negative electrode. By connecting the cell 1 in series, a single battery group 10A and 10B was formed. At this time, the same spacer 11 as in the first embodiment was arranged between the cells 1. As shown in FIG. 9, the battery group is arranged in a direction in which the wide surface of the cell 1 is substantially perpendicular to the bottom surface of the housing, and these 12 battery groups are fixed to a pressurizing jig (22). , 33) was used to obtain a battery group 10C. The housing and the battery group 10C were fixed using screws. Note that FIG. 9 is a plan view seen from the upper surface of the lid surface of the housing. In this comparative example, the electrical components are arranged on the path connecting the external terminal 9 to the cell 1 as in the first embodiment. The electrodes of the battery group 10C to the external terminals were electrically connected by connecting the same electrical components as in Example 1 using a bus bar and a cable. FIG. 11 shows the results of this comparative example when the battery having the above configuration is provided with the same current application conditions and the surrounding cooling environment as in the first embodiment, and the battery is in a substantially steady state.

(Comparative Example 2)
The battery configuration described in Patent Document 1 was simulated and used as a comparative example. Specifically, a cell 1 made by using an electrode made of an Al collector foil and a positive electrode material having a layered structure as a positive electrode and an electrode made of a Cu current collector foil and a carbon material as a negative electrode and winding those electrodes. Was used, and only the battery group 10D was made into a group consisting of six cell cells in the same manner as in Example 1 so that only the battery group 10D could be compared with Example 1. The battery group 10D was arranged so that the side surfaces of the battery group 10D were in physical contact with each other. The electrical components will be placed on the path connecting the electrodes of the battery group 10D from the external terminals, and the same electrical components as in Example 1 shall be connected from the electrodes to the external terminals using a bus bar and a cable. Electrically connected with. Further, in order to provide substantially the same cooling environment as in Example 1, a housing 77 and a lid 88 were newly provided around the battery group, and a comparative experiment was conducted. FIG. 11 shows the results when the battery group 10D having such a configuration is provided with the same current application conditions and the surrounding cooling environment as in Example 1 and becomes a substantially steady state.

(Comparative Example 3)
In this comparative example, an electrode made of an Al collector foil and a positive electrode material having a layered structure is used as a positive electrode, and an electrode made of an Al collector foil and a spinel-based oxide is used as a negative electrode, and these electrodes are simply wound. Six batteries were laminated as shown in FIG. 10, and the periphery thereof was fixed using a pressurizing jig for fixing to obtain a battery group 10D. In this comparative example, the battery having the above configuration is provided with the same current application conditions as in Example 1 and the surrounding cooling environment, and the results when the battery is in a substantially steady state are shown in FIG.

As a result of giving the battery group the conditions shown in this example and the comparative example, when the temperature of the battery group reached a nearly steady state, the battery temperature was higher than the environmental temperature. In FIGS. 11 and 12, the temperature rise from the environmental temperature was the largest among the battery groups existing in Comparative Example 1, which had the highest temperature rise among the examples and comparative examples in the present invention. Assuming that the temperature rise of the battery was 100%, the temperature rise ratios of the cells existing in each example were compared.

In Comparative Example 1, cell numbers are assigned in order from the left cell battery shown in FIG. On the other hand, except for Comparative Example 1, since the temperature of the stacked battery groups was substantially the same for the cells having the same height positional relationship from the bottom surface, only six batteries having different heights were described. On the other hand, in the examples other than Comparative Example 1, the height from the bottom surface of the housing increases in ascending order of the cell numbers in the figure.

The results of each figure will be described in detail below.

FIG. 11 shows the temperature rise ratio of Example 1, which is an example to which the present invention is applied, together with Comparative Examples 1 and 2. From the figure, in Comparative Example 1, the cell No. 1 which is the central portion where the batteries are stacked. It can be seen that the temperatures of 6 and 7 are maximized. This is cell No. With a battery near 7, the amount of heat generated by the surrounding batteries is not dissipated, so not only the temperature of the battery itself but also the temperature of the surrounding batteries is high, and because there is no temperature difference, it becomes difficult for heat to flow, resulting in This is because the battery temperature is high.

On the other hand, in Example 1 and Comparative Example 2, as shown in FIG. 11, the temperature rise ratio of the six battery groups is reduced by the decrease in the number of the stacked battery groups, and the temperature rise ratio of the six battery groups is 12 in the comparative example. It can be seen that it is reduced compared to 1. Due to this effect, it is considered that the temperature rise is suppressed in Comparative Example 2 as compared with Comparative Example 1. In addition, in the first embodiment, the surfaces of the battery groups in which the external terminals are arranged are opposed to each other in the housing, and the battery groups are not thermally and physically connected to each other. As a result, it is considered that the thermal resistance is reduced as compared with Comparative Example 2, and the temperature of the cell is also reduced as compared with Comparative Example 2.

In FIG. 12, an electrode made of an Al collector foil and a positive electrode material having a layered structure is used as a positive electrode, and an electrode made of an Al collector foil and a spinel-based oxide is used as a negative electrode, and these electrodes are simply wound around. A case where six batteries are used and the configuration in the present invention is compared with the configuration in a known example is shown. The results shown in FIG. 12 show that the effect of the present invention appears even if the battery type is changed.

(Example 3)
Subsequently, Example 3 will be described. The difference between the third embodiment and the first embodiment is that the water-cooled jacket 107 is provided on the side surface of the housing 7. The same drawings as those in the first embodiment are designated by the same drawing numbers.

FIG. 6 shows the structure of the third embodiment. In this embodiment, as shown in FIG. 6, a water-cooled jacket 107 is provided on the side surface of the housing 7. Therefore, in addition to the effect of the first embodiment, the cooling performance can be further enhanced.

(Example 4)
Subsequently, Example 4 will be described. The difference between the fourth embodiment and the first embodiment is that air-cooling fins 177 are provided on the side surface of the housing 7. The same drawings as those in the first embodiment are designated by the same drawing numbers.
FIG. 7 shows the structure of the fourth embodiment. In this embodiment, as shown in FIG. 7, air-cooling fins 177 are provided on the side surfaces of the housing 7. Therefore, in addition to the effect of the first embodiment, the cooling performance can be further enhanced. Further, since the air cooling method is used in this embodiment, the cooling performance is lower than that in the third embodiment, but the device required for water cooling is not required, and the device can be made compact when mounted on a vehicle.

(Example 5)
Subsequently, Example 5 will be described. The difference between the fifth embodiment and the first embodiment is that the pressurizing binding member 2 is also used as the housing 277. The same drawings as those in the first embodiment are designated by the same drawing numbers.

FIG. 8 shows the structure of the fifth embodiment. In this embodiment, as shown in FIG. 8, the side surface of the housing 277 is in direct contact with the battery groups 10A and 10B, and the pressurizing binding jig 3 is connected to the housing 277. ..

As shown in FIG. 8, in this embodiment, the pressurizing binding member 3 is directly connected to the housing 277. Further, in order to increase the contact area between the pressurizing binding jig 3 and the housing 277, in this embodiment, the housing side surface recesses 277A and 277B for accommodating the pressurizing binding jig 3 and the two housing side recesses. A housing side surface convex portion 277C arranged between 277A and 277B is provided. With such a structure, the side surface portions of the battery groups 10A and 10B come into direct contact with the housing 277 without using the pressurizing binding jig, so that the cooling performance is improved. Further, by arranging the pressurizing binding jigs 3 of the battery groups 10A and 10B in the housing side recesses 277A and 277B, the contact area of the pressurizing binding jig 3 with the housing 277 increases, and the pressurizing binding jig 3 increases. Heat dissipation from the tool 3 is promoted. Further, since the two pressurizing binding jigs 3 are also in contact with the housing side surface convex portion 277C, heat dissipation from the pressurizing binding jig 3 is further promoted.

The present invention will be briefly summarized above.

The battery pack 100 of the present invention includes a battery cell having a pair of wide side surfaces, a pair of narrow side surfaces, a bottom surface connecting the wide side surfaces and the narrow side surfaces, and an upper surface on which external terminals are arranged. The first battery group (10A) having 1) and having the wide side surfaces of the battery cell (1) facing each other and stacking a plurality of the first battery group (10A) and the wide side surfaces of the battery cell (1) facing each other are stacked. A housing (7) for accommodating a second battery group (10B), a first battery group (10A), and a second battery group (10B) is provided, and the outside of the first battery group (10A) is provided. The surface on which the terminals (12, 13) are arranged and the surface on which the external terminals (12, 13) of the second battery group (10B) are arranged are arranged so as to face each other. With such a structure, the four surfaces of the battery groups 10A and 10B, that is, the two sides of the battery groups 10A and 10B (the surface on which the pressurizing binding jig 2 is arranged) and the bottom surface of the cell 1 are provided. , The lowermost surfaces of the battery groups 10A and 10B (the lower surface on which the pressurizing binding jig 3 is arranged) can be used for cooling by directly contacting the housing 7, so that the cooling performance is improved. ..

Further, the battery pack (100) described in the present invention has a surface on which the external terminals (12, 13) of the first battery group (10A) are arranged and an external terminal (12) of the second battery group (10B). , 13), electrical components are arranged in the space between the arranged surfaces. With such a structure, the space for gaining the creepage distance of the battery groups 10A and 10B can be used as a storage space for electrical components, and the size of the battery pack 100 can be prevented from becoming large.

Further, in the battery pack (100) described in the present invention, if at least two or more of the substrate (20), the relay (23), or the fuse (22) are used as electrical components, two or more parts are included. Since it can be made into one assembly, the effect of improving workability can be obtained.

Further, the battery pack (100) described in the present invention is a battery pack in which electrical components are integrated with an insulating member. With such a structure, while ensuring the insulation between the battery groups 10A and 10B, it is not necessary to arrange the electrical components in the narrow space between the battery group 10A and the battery group 10B. Therefore, since the support base 4 to which the electrical components are fixed can be collectively fixed to the housing 7 or the like, the workability can be improved while ensuring the insulation between the battery groups 10A and 10B.

Further, in the battery pack (100) described in the present invention, the electrical components are a substrate (20), a relay, (23) and a fuse (23), and one side of the insulating member is the substrate (20) and the other side. A relay (23) and a fuse (22) are arranged in the vehicle. With such a structure, the BMS 20 which is a flat member can be arranged on one side, which is wasteful as compared with a structure in which the relay 23 is arranged on one side of the support base 4 and the fuse 22 is arranged on the other side. No uneven space is generated. Therefore, it contributes to miniaturization.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various designs are designed without departing from the spirit of the present invention described in the claims. You can make changes. For example, the above-described embodiments have been described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to those having all the described configurations. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Further, it is possible to add / delete / replace a part of the configuration of each embodiment with another configuration.

1 Single battery 2 Pressurizing binding jig 3 Pressurizing binding jig 4 Support base 5 Fixing bracket 6 Wiring 7 Housing 8 Lid 9 Terminal 10A, 10B Battery group

Claims (6)

In a battery pack having a battery cell comprising a pair of wide side surfaces, a pair of narrow side surfaces, a bottom surface connecting the wide side surfaces and the narrow side surfaces, and a top surface on which external terminals are arranged.
The first battery group in which a plurality of batteries are stacked with the wide side surfaces of the battery cells facing each other,
A second group of batteries in which a plurality of batteries are stacked so that the wide side surfaces of the battery cells face each other,
A housing for accommodating the first battery group and the second battery group,
A pair of pressurizing binding jigs arranged to face each of the wide side surface of the battery cell arranged at the top and the wide side surface of the battery cell arranged at the bottom.
Two housing side recesses for accommodating the pressurizing binding jig,
The housing side surface convex portion disposed between these two housing side surface recesses,
Equipped with
The wide side surfaces forming the uppermost bottom of each of the first battery group and the second battery group are arranged in the housing in a positional relationship not facing each other .
The surface on which the external terminals of the first battery group are arranged and the surface on which the external terminals of the second battery group are arranged are arranged so as to face each other.
A battery pack characterized in that the pair of pressurizing binding jigs are also brought into contact with the convex portion on the side surface of the housing. In the battery pack according to claim 1 ,
A battery pack characterized in that electrical components are arranged in a space between a surface on which an external terminal of the first battery group is arranged and a surface on which an external terminal of the second battery group is arranged. .. In the battery pack according to claim 2 ,
The battery pack is characterized in that the electrical component is at least two or more of a substrate, a relay, or a fuse. In the battery pack according to claim 3 ,
The electrical components are battery packs, each of which is integrated with an insulating member. In the battery pack according to claim 4 ,
The electrical components are a substrate, a relay, and a fuse.
A battery pack characterized in that a substrate is arranged on one side of the insulating member, and a relay and a fuse are arranged on the other side. In the battery pack according to any one of claims 2 to 5 , the battery pack
The electrical component is a battery pack comprising a connecting member electrically connected to the battery terminal of the first battery group and the battery terminal of the second battery group.

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