JP2019012619A - Battery pack - Google Patents

Abstract

To provide a battery pack that is configured so that surfaces on which respective external terminals of battery groups are opposed to each other in an enclosure to prevent the battery groups from being physically connected to each other, which can reduce heat resistance of the battery groups, reducing temperatures of electric cells in the battery groups.SOLUTION: The battery pack according to the present invention has battery cells comprising a pair of wide side surfaces, a pair of narrow side surfaces, a bottom surface connecting the wide side surfaces to the narrow side surfaces, and an upper surface having an external terminal arranged thereon; and comprises a first battery group having the battery cells laminated in plural number therein by opposing the wide side surfaces of the battery cells to each other, a second battery group having the battery cells laminated in plural number by opposing the wide side surfaces of the battery cells to each other, and an enclosure for storing the first battery group and the second battery group. The upper surface having the external terminal arranged thereon of the first battery group and the upper surface having the external terminal arranged thereon of the second battery group are arranged to oppose to each other.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a battery pack.

Against the backdrop of environmental problems and resource depletion problems, development of energy-saving products with a low environmental impact is required for the preservation of the global environment. As one of the products that lead to the reduction of CO _2, eco-cars represented by hybrid electric vehicles and electric vehicles are attracting attention, and the number of units sold is growing. The demand for in-vehicle secondary batteries mounted on these eco-cars is also increasing. Examples of the in-vehicle secondary battery include a lithium ion secondary battery, a lead storage battery, and a nickel metal hydride battery. Among these, since lithium ion secondary batteries generally have a higher discharge potential than lead batteries or nickel metal hydride batteries, they are promising because they can be reduced in size and energy density.

  The points required for lithium ion secondary batteries for full-scale application include, for example, further higher energy density, higher output density, and longer life. In order to increase the output of the battery, it is effective to input and output a large current from the battery as well as increasing the potential. However, when a large current is input / output from the battery, heat generated from the internal resistance of the battery is generated inside the battery. When the generated heat cannot be sufficiently removed from the battery, the battery temperature rises. Battery characteristics, such as battery capacity and internal resistance, of lithium ion batteries differ depending on the battery temperature. In particular, the higher the battery temperature, the more the battery deterioration progresses, and the capacity reduction and the internal resistance increase often occur. Therefore, it is necessary to develop a technology for improving the heat dissipation performance of the battery.

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

  Accordingly, various battery arrangement configurations have been developed in a battery group formed by combining a plurality of single cells. For example, Patent Document 1 describes a configuration in which two battery groups in which five unit cells are stacked in a direction substantially perpendicular to the wide surface of the unit cells are arranged side by side on a plate constituting the bottom surface of the housing. Has been. In general, since the same current value is applied to the batteries connected in series, if the batteries have substantially the same internal resistance, the temperatures of the batteries are comparable. In this case, since the heat flow between the batteries is less likely to occur, the higher the number of stacked batteries, the closer the temperature of the central part of the stacked battery group approaches the heat insulation state, and the higher the temperature compared to the end of the battery group. It has been known. When the battery group arranged in series as in Patent Document 1 is divided into two rows, the battery group has the same configuration as five batteries stacked when viewed from the bottom of the casing. There is an advantage that the temperature of the battery is likely to decrease. In addition, since the series battery group is divided, there is a feature that it is possible to reduce the height.

U.S. Pat. No. 9,406,916

  As in the structure described in Patent Document 1, when the side surfaces of the battery groups are physically connected physically, the path through which heat escapes from the connection surfaces of the battery groups is sandwiched between the battery groups. It is necessary to radiate heat through the member and through the housing in front of the member, and there is a problem that the heat radiation path becomes redundant. When the heat dissipation path is made redundant, the thermal resistance tends to increase, and there is room for improvement in order to improve the heat dissipation.

  In such a configuration, when the cooling efficiency decreases (for example, when the flow rate of forced air is small or when the input / output current is large and the unit battery generates a large amount of heat), the battery temperature within 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 cells arranged near the center is high, and there is a possibility that the deterioration will proceed. This invention is made | formed in view of the said subject, and makes it a subject to provide the battery pack with a small temperature difference between battery groups.

  A battery pack according to the present invention includes a battery cell including a pair of wide side surfaces, a pair of narrow side surfaces, a bottom surface connecting the wide side surface and the narrow side surface, and an upper surface on which external terminals are arranged. A plurality of first battery groups stacked with the wide side surfaces of the battery cells facing each other, a second battery group stacked with a plurality of the side surfaces facing the wide side of the battery cells, and the first A housing for housing one battery group and a second battery group, a surface on which the external terminals of the first battery group are disposed, and a surface on which the external terminals of the second battery group are disposed. Are arranged opposite to each other.

  According to the present invention, the surfaces of the battery groups on which the external terminals are arranged are opposed to each other within the casing, and the battery groups are configured not to be physically and physically connected, thereby reducing the thermal resistance of the battery groups. Thus, the temperature of the single cells in the battery group can be reduced.

The figure for demonstrating an example of the specific structure of the battery group in Example 1 and 2. The figure for demonstrating an example of the concrete wiring structure implemented when connecting the cell which exists in the battery group made to oppose in Example 1 and 2 electrically in series The exploded perspective view for demonstrating an example of the structure of the concrete battery module implemented when arrange | positioning the battery group in Example 1 facing in a housing | casing FIG. 3 is a plan view when the battery module shown in FIG. 3 is removed and the inside of the module is viewed from the upper surface of the lid. FIG. 4 is an exploded plan view of a part where the support base and the 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. FIG. The figure for demonstrating an example of the specific structure of the battery group in Example 4. FIG. The top view at the time of removing a cover and seeing from the upper surface in order to explain an example of the composition of the concrete battery module carried out when arranging the battery group in Example 5 to oppose in the case 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 the comparative example 1 and the comparative example 2. FIG. The figure which compares the temperature rise ratio of the battery group in Example 2 and 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. In addition, the cooling environment in the present invention is an exemplification, and the present invention can also be applied when other refrigerants other than air and water are used.

  Although the lithium ion secondary battery is illustrated as the secondary battery in the present invention, this configuration can be applied to other types of storage batteries. In addition, 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 Al current collector foil and a positive electrode material having a layered structure is used as the positive electrode, and an electrode made of 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 for the current collector foil of the negative electrode, the heat dissipation can be improved. In this embodiment, a prismatic battery is used as the shape of the lithium ion battery. However, for example, a battery of a laminate type, a cylindrical type or the like known as other shapes can also be effective.

  The number of battery groups included in the housing is such that, as in the configuration of the present invention, the side surface of the battery is in physical and thermal contact with the side surface of the housing so that the heat dissipation path from the side surface of the battery group is Any number may be used as long as it can be shortened, but an even number is preferable to ensure the stability of the battery pack. For example, when the number of battery groups is two as in the embodiment of the present invention, the battery groups can be placed in physical and thermal contact with the left and right side surfaces of the housing.

  In addition, the number of batteries constituting the battery group can be the configuration according to the present invention, and the effect of the present invention can be obtained by any number as long as it can be accommodated in the casing and a desired voltage and capacity can be secured. As the heat dissipation effect, the smaller the number of unit cells stacked in one battery group, the more effective, but the number is preferably 100 or less, more preferably 20 or less, and most preferably 10 or less. By using six batteries as in the embodiment of the present invention, a battery pack having a small size and a cooling property can be obtained.

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

  The effect of the present invention can be obtained even if, for example, an insulating sheet or a member having high thermal conductivity is arranged between the single cells forming the battery group, and the effect of the present invention can be obtained without arranging them. In addition, the effects of the present invention can be obtained even if three-dimensional structures such as protrusions and grooves having various shapes such as rails and dots are introduced into the insulating sheet and the member having high thermal conductivity. When the side surface of the unit cell is covered with an insulating material, a material having high thermal conductivity such as aluminum, aluminum die casting, copper, or iron can be used as a material for these members. Further, when the side surface of the unit cell is not covered with an insulating material, polypropylene, polyamide, polyetherimide, PPS, PPA, PBT, or the like, or a high thermal conductive resin can be used.

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

  An insulating member is a support base that is created by using 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, Battery Management System: BMS). Or at least one of electrical components such as a relay necessary for precharging, a shunt resistor, and a conductive wiring such as a bus bar and a conductive wire. In addition, the support base may include a screw, a screw hole, or a fixture that can fix these electrical components. By integrating the electrical components described above with the support base using these fixing devices, it is possible to connect electrical components such as a safety mechanism and the battery group via conductive wiring and to electrically connect to external terminals. it can. Thereby, since an insulating member can be introduced between the terminal surfaces of each battery group, it is possible to obtain a battery pack having high heat dissipation while providing crush safety.

  In addition, the present invention is not particularly limited in the method and positional relationship of attaching a safety mechanism or the like to these support bases. For example, these devices may be arranged / built in the top, bottom, side, and inside of the insulating support base. Also, 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 properties of the two battery groups can be secured when the battery groups come close to each other by crushing. For example, the support base may be a thin plate shape, 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 of the present invention can be obtained regardless of how the single cells constituting the battery group are electrically connected. For example, the effects of the present invention can be obtained even if the battery groups are connected in parallel by devising wiring. Here, as an example, an example will be described in which single cells in battery groups are connected in series, and two opposing battery groups are also connected in series.

Examples of the method of connecting the battery groups in series after the battery groups are opposed to 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 using a method such as screws or welding using a part of the bus bar or wiring extended for connection. However, the electrical connection method is not limited to these.
(B) A 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 that a conductive part such as a bus bar or a cable is built in the support base and is electrically connected via the conductive member.
(C) A method of directly connecting battery groups using a cable.
(D) The method of electrically connecting cables via the support stand which contains an insulating member in a structural member mentioned above, etc. are mentioned.

  In addition to electrically connecting the cells in series or in parallel, the battery group preferably physically binds the cells using a fixing jig. When the side surface of the unit cell is covered with an insulating material, a material having high thermal conductivity such as aluminum, aluminum die casting, copper, or iron can be used as the material for the fixing jig. Further, when the side surface of the unit cell is not covered with an insulating material, polypropylene, polyamide, polyetherimide, PPS, PPA, PBT, or the like, or a high thermal conductive resin can be used. Further, the present invention is not limited to the restraining method. For example, even when two battery groups were bound using one set of fixing jigs, or when fixed using two sets of fixing jigs, the effect appeared. Even if at least a part of the fixing jig is a casing, the effect of the present invention is obtained.

  The contact method of each member such as the housing, the battery group, and the support base is not particularly limited. For example, the effect of the present invention can be achieved by bonding with an adhesive or the like, or connection through a fixing device such as a bolt or nut. In this embodiment, the shape of the housing is a rectangular parallelepiped, but the shape is not particularly limited. Moreover, the effect in this invention is not limited to the electric current application conditions to a battery pack, or cooling conditions.

  Since a support bar exemplified in the present invention is provided with a bus bar and a conductive wire having good thermal conductivity, 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 in a portion that is in thermal contact with the support base.

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

  Examples of the case include a resin case and a metal case, but are not particularly limited. A case made of a heat conductive metal such as aluminum, aluminum die casting, copper, or iron is preferable.

  In the example of the present invention, the position of the external terminal that appears from the lid is arranged above the space where the electrical component can be arranged, but the position of the external terminal can also be arranged above the binding jig for pressurization. Also in this case, the effect in the present invention can be obtained by adopting the structure in the present invention. In the embodiment, a conductive wire such as a bus bar is disposed on a support base including an insulating member as a constituent member, and various electrical components are connected to the support base using screws to be electrically connected. A 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. A battery pack 100 according to the present invention is shown in FIG. 3 as two battery groups 10A and 10B, a metal casing 7 that houses the two battery groups 10A and 10B, a lid 8 that closes the opening of the casing 7. It is comprised from the support stand 4 which has arrange | positioned the electrical component which is not. In addition, the support base 4 is arrange | positioned in the electrical equipment arrangement | positioning space 4A between the battery group 10A and the battery group 10B. The battery groups 10 </ b> A and 10 </ b> B are arranged so that the terminals (positive electrode terminal 12, negative electrode terminal 13) of the unit cell 1 are opposed to each other, and are electrically connected to each other by the wiring 6. An external terminal 9 is disposed on the lid 8 and is electrically connected to the wiring 6, and power is 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 unit cell 1 includes a pair of wide surfaces, a pair of narrow surfaces, a bottom surface, and an upper surface. A positive electrode terminal 12 and a negative electrode terminal 13 are disposed on the upper surface. Insulating spacers 11 are disposed between the single cells 1, and the single cells 1 are stacked so that the positive and negative electrodes of the terminals are staggered.

  A pair of binding jigs 3 for pressurization are arranged to face the wide surface of the unit cell 1 arranged at the top and the wide surface of the unit cell 1 arranged at the bottom.

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

  Next, FIG. 2 shows the connection between the wiring 6 and each cell 1. The wiring 6 is divided into three types: a wiring 6A that is connected to the external terminal 9, a wiring 6C that connects the cells 1 to each other, and a wiring 6B that connects 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.

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

  Next, the support table 4 will be described with reference to FIG. A BMS 20 and a shunt resistor 21 are disposed on one surface of the support base 4, and a fuse 22 and a relay 23 are disposed on the other surface. With the BMS 20 and the shunt resistor 21 assembled together, 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 concave portions are provided on the other surface, and the fuse 22 and the relay 23 are accommodated therein. By adopting such a structure, the integrated assembly of the support base 4 and the electrical equipment can be reduced in size. Note that the fuse 22 and the relay 23 may be connected to each other through the connection wiring 6A2 and then assembled to the support base 4. Moreover, when assembling the electrical equipment, it is assembled with parts such as screws, but the way of assembling is not limited thereto.

  Subsequently, the characteristic part of this embodiment will be described with reference to FIG. 3 again.

  In the present embodiment, the four surfaces of the battery groups 10A and 10B, that is, the two side surfaces of the battery groups 10A and 10B (the surface on which the pressing restraint jig 2 is disposed), the bottom surface of the unit cell 1, the battery group 10A, The bottom surface of 10B (the surface on which the lower pressurizing binding jig 3 is disposed) is housed in the housing 7 so as to be in direct contact with the housing. Therefore, the cooling performance is most improved when storing two or more battery groups 10A and 10B. On the other hand, in order to improve the cooling efficiency, it is necessary to store the battery group 10A so that the surface on which the terminals of the battery group 10A are disposed and the surface on which the terminals of the battery group 10B are disposed. Therefore, in this invention, it comprised so that the electrical equipment required for the battery pack 100 might be assembled | attached to the insulating support stand, and it may arrange | position between battery group 10A and battery group 10B. Therefore, while improving the cooling performance as the battery pack 100, the insulation properties of the two battery groups 10A and the battery group 10B can be secured, and the battery pack 100 can be prevented from being enlarged. The point that the enlargement of the battery pack 100 can be prevented will be described in more detail. Originally, if the terminal side surface of the battery group 10 </ b> A and the terminal side surface of the battery group 10 </ b> B are made to face each other, it is necessary to earn a creepage distance for the two battery groups, and the volume of the battery pack 100 increases accordingly. Therefore, since the space for earning the creepage distance of the battery groups 10 </ b> A and 10 </ b> B can be overlaid on the space where the support base is arranged, the battery pack 100 can be prevented from being enlarged.

  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 casing 7 or the like in a lump without performing the placement operation of the electrical components in the narrow space between the battery group 10A and the battery group 10B. Workability at the time of 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. By adopting such a structure, the planar member BMS 20 can be arranged on one side, which is wasteful compared to 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 comes to contribute to miniaturization.

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

  An electric current was applied to the battery pack produced as described above. At this time, a member having a low thermal conductivity was arranged on the lower surface of the casing and a current was applied, and the test results were obtained in a thermostatic chamber without substantially air flow. The current value was applied so that the calorific value from the battery was calculated from the current value and averaged 3 W. In this example, FIG. 11 shows the temperature behavior when the battery pack is subjected to the above-described conditions and is in a substantially steady state.

(Example 2)
In this example, an electrode made of an Al current collector foil and a positive electrode material having a layered structure as a positive electrode, and an electrode made of an Al current collector foil and a spinel oxide as a negative electrode, and these electrodes are rolled up. Six batteries were stacked as shown in FIG. 1, and the periphery was fixed using a fixing pressure jig to obtain a battery group. This example gives the current application conditions and ambient cooling environment similar to those of Example 1 to the battery having the above-described configuration, and FIG.

(Comparative Example 1)
Using an electrode made of Al current collector foil and a positive electrode material having a layered structure as a positive electrode, an electrode made of Cu current collector foil and a carbon material as a negative electrode, and using a single battery obtained by winding those electrodes, A single battery group 10A, 10B was made by connecting the single batteries 1 in series. At this time, spacers 11 similar to those in Example 1 were disposed between the single cells 1. As shown in FIG. 9, the cell group 1 is arranged in a direction in which the wide surface of the unit cell 1 is substantially perpendicular to the bottom surface of the housing as shown in FIG. 9. , 33) to obtain a battery group 10C. The casing and the battery group 10C were fixed using screws. FIG. 9 is a plan view seen from the upper surface of the lid surface of the housing. In this comparative example, as in the first embodiment, the electrical components are arranged on the path connecting the single cell 1 from the external terminal 9. From the electrode part of the battery group 10C to the external terminal, the same electrical components as in Example 1 were connected using a bus bar and a cable. This comparative example gives the current application conditions and the surrounding cooling environment similar to those of Example 1 to the battery having the above-described configuration, and FIG.

(Comparative Example 2)
A battery configuration described in Patent Document 1 was simulated and used as a comparative example. Specifically, a unit cell 1 formed by winding an electrode made of an Al current 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. As in Example 1, a group consisting of six single cells was used so that only the battery group 10D could be compared with Example 1. The battery group 10D was disposed in such a manner that the side surfaces of the battery group 10D were in physical contact with each other. Electrical components are arranged on a path connecting the electrodes of the battery group 10D from the external terminals, and the same electrical components as those in the first embodiment are connected to the electrical components from the electrode portions to the external terminals using bus bars and cables. Electrically connected. Further, in order to provide a cooling environment substantially the same as in Example 1, a case 77 and a lid 88 were newly provided around the battery group, and a comparative experiment was performed. FIG. 11 shows the result when the battery group 10D having such a configuration is given a current application condition and an ambient cooling environment similar to those of Example 1 and is in a substantially steady state.

(Comparative Example 3)
In this comparative example, an electrode made of an Al current collector foil and a positive electrode material having a layered structure is used as the positive electrode, and an electrode made of Al current collector foil and a spinel oxide is used as the negative electrode. Six batteries were stacked as shown in FIG. 10, and the periphery thereof was fixed using a fixing pressure jig to obtain a battery group 10D. This comparative example gives the current application conditions and the surrounding cooling environment similar to those of Example 1 to the battery having the above-described configuration, and 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 almost reached a steady state, the battery temperature increased compared to the environmental temperature. 11 and 12, the temperature rise from the ambient temperature was the largest among the battery groups present in Comparative Example 1 in which the temperature rise was the highest among the examples and comparative examples of the present invention. Assuming that the temperature rise of the battery is 100%, the temperature rise ratio of the unit cells present in each example was compared.

  About the comparative example 1, cell No. is attached in order from the left single battery shown in FIG. On the other hand, except for Comparative Example 1, since the unit cell having the same positional relationship with respect to the height from the bottom surface was the same temperature in the stacked battery group, only six unit cells having different heights were described. On the other hand, in the examples excluding Comparative Example 1, the height from the bottom surface of the housing is increased 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 increase 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. It can be seen that the temperatures of 6 and 7 are maximum. This is cell No. In the battery near 7, the amount of heat generated in the surrounding batteries is not dissipated, so not only the temperature of its own battery but also the surrounding battery temperature is high. 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 increase ratio of 6 battery groups is reduced by 12 because the number of stacked battery groups is decreased. It can be seen that it is decreased compared to 1. Due to this influence, it is considered that the temperature increase is suppressed in Comparative Example 2 as compared with Comparative Example 1. In addition, in Example 1, the surfaces on which the external terminals of the battery groups are arranged are opposed to each other within the casing, and the battery groups are not thermally connected physically. As a result, the thermal resistance is reduced as compared with Comparative Example 2, and the temperature of the unit cell is considered to be reduced as compared with Comparative Example 2.

  In FIG. 12, an electrode made of Al current collector foil and a positive electrode material having a layered structure is used as the positive electrode, and an electrode made of Al current collector foil and spinel oxide is used as the negative electrode. The case where the structure in this invention and the structure in a well-known example are compared using six batteries is shown. From the results shown in FIG. 12, it can be seen that the effect of the present invention is exhibited even if the battery type is changed.

(Example 3)
Next, Example 3 will be described. The third embodiment differs from the first embodiment in that a water cooling jacket 107 is provided on the side surface of the housing 7. In addition, the same drawing number is attached | subjected about the structure similar to Example 1. FIG.

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

(Example 4)
Next, Example 4 will be described. The fourth embodiment is different from the first embodiment in that air cooling fins 177 are provided on the side surface of the housing 7. In addition, the same drawing number is attached | subjected about the structure similar to Example 1. FIG.
FIG. 7 shows the structure of the fourth embodiment. In this embodiment, air cooling fins 177 are provided on the side surface of the housing 7 as shown in FIG. Therefore, in addition to the effects of the first embodiment, the cooling performance can be further enhanced. In addition, since this embodiment uses an air-cooling system, the cooling performance is lower than that of the third embodiment, but an apparatus or the like necessary for water-cooling is not required, and the apparatus can be made compact when mounted on a vehicle.

(Example 5)
Next, Example 5 will be described. The fifth embodiment differs from the first embodiment in that the pressurizing binding member 2 is also used as the housing 277. In addition, the same drawing number is attached | subjected about the structure similar to Example 1. FIG.

  FIG. 8 shows the structure of the fifth embodiment. In the present embodiment, as shown in FIG. 8, the side surface of the housing 277 is in direct contact with the battery groups 10 </ b> A and 10 </ b> B, 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 this embodiment, in order to increase the contact area between the pressurizing binding jig 3 and the housing 277, the housing side surface recesses 277A and 277B for accommodating the pressurizing binding jig 3 and two housing side surface recesses are provided. A casing side surface convex portion 277C disposed between 277A and 277B is provided. By adopting such a structure, the side surfaces of the battery groups 10A and 10B are in direct contact with the casing 277 without using the pressurizing binding jig, so that the cooling performance is improved. Further, the pressurizing restraint jig 3 of the battery groups 10A and 10B is disposed in the housing side surface recesses 277A and 277B, whereby the pressurizing restraint jig 3 has an increased contact area with the housing 277, and the pressurization restraint jig 3 is increased. Heat dissipation from the tool 3 is promoted. Further, since the two pressurizing restraining jigs 3 are also brought into contact with the casing side surface convex portion 277C, heat radiation from the pressurizing restraining jig 3 is further promoted.

  The present invention will be briefly described above.

  In the battery pack 100 of the present invention, 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 ( 1), a plurality of first battery groups (10A) stacked with the wide side surfaces of the battery cells (1) facing each other, and a plurality of stacked with the wide side surfaces of the battery cells (1) facing each other. A second battery group (10B), a first battery group (10A), and a housing (7) for housing the second battery group (10B), and the exterior of the first battery group (10A) The surface on which the terminals (12, 13) are disposed and the surface on which the external terminals (12, 13) of the second battery group (10B) are disposed are opposed to each other. By adopting such a structure, the four surfaces of the battery groups 10A and 10B, that is, the two side surfaces of the battery groups 10A and 10B (the surface on which the pressurizing binding jig 2 is disposed), the bottom surface of the unit cell 1 Since the lowermost surfaces of the battery groups 10A and 10B (the surface on which the lower pressing restraining jig 3 is disposed) can be used for cooling by directly contacting the casing 7, the cooling performance is improved. .

  In addition, the battery pack (100) according to the present invention includes 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) is disposed in the space between the surfaces on which the electrical components are disposed. With such a structure, the space for the creepage distance of the battery groups 10 </ b> A and 10 </ b> B can be used as a storage space for electrical components, and the battery pack 100 can be prevented from being enlarged.

  Further, the battery pack (100) according to the present invention has two or more parts as long as at least two of the board (20), the relay (23), and the fuse (22) are used as electrical components. Since it can be made into one assembly, the effect of improving workability can be obtained.

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

  In the battery pack (100) according to the present invention, the electrical components are the substrate (20), the relay, (23), and the fuse (23), and the substrate (20) and the other side are on one side of the insulating member. A relay (23) and a fuse (22) are arranged on the side. By adopting such a structure, the planar member BMS 20 can be arranged on one side, which is wasteful compared to 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 comes to contribute 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 can be made without departing from the spirit of the present invention described in the claims. It can be changed. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described. Further, a part of the configuration of an embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of an embodiment. Furthermore, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

DESCRIPTION OF SYMBOLS 1 Cell 2 Pressurization restraint jig 3 Pressurization restraint jig 4 Support stand 5 Fixing metal fitting 6 Wiring 7 Case 8 Lid 9 Terminal 10A, 10B Battery group

Claims (5)

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 an upper surface on which external terminals are disposed.
A first battery group in which a plurality of the battery cells are stacked with the wide side surfaces thereof facing each other;
A second battery group in which a plurality of the battery cells are stacked with the wide side surfaces of the battery cells facing each other;
A housing for housing the first battery group and the second battery group,
The battery pack characterized in that the surface on which the external terminals of the first battery group are disposed and the surface on which the external terminals of the second battery group are disposed are opposed to each other. The battery pack according to claim 1,
A battery pack, wherein electrical components are arranged in a space between a surface on which the external terminals of the first battery group are disposed and a surface on which the external terminals of the second battery group are disposed. . The battery pack according to claim 2,
The battery pack is characterized in that the electrical component is at least two of a substrate, a relay, and a fuse. The battery pack according to claim 3,
The battery pack is characterized in that each of the electrical components is integrated with an insulating member. The battery pack according to claim 4,
The electrical components are a board, a relay, and a fuse,
A battery pack comprising a substrate on one side of the insulating member and a relay and a fuse on the other side.

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