JP2012186124A - Battery pack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a battery pack which cools high output density type secondary batteries more efficiently than high energy density type secondary batteries thereby efficiently achieving both high output performance and high energy performance.SOLUTION: A battery pack includes: multiple high output density type secondary batteries, multiple high energy density type secondary batteries, and a case housing these secondary batteries as a battery pack. The case has an air intake port for taking in outer air into the interior of the case and a discharge port discharging air in the interior to the exterior of the case.

Description

  The present invention relates to a battery pack capable of cooling a secondary battery in a case.

As a conventional assembled battery formed by combining different types of single cells, a bipolar secondary battery in which a plurality of single battery layers (cells) are stacked and a plurality of general batteries (secondary batteries) are electrically connected in series. An assembled battery including a general battery group that is connected has been proposed (see, for example, Patent Document 1). In this case, the bipolar secondary battery has a detection tab connected to each cell layer. The general battery group is formed by connecting the same number of general batteries as the number of the combination of the positive electrode and the negative electrode of the bipolar secondary battery via the tab connecting portion. And the tab connection part for every series of the general battery of the same electric potential level and the tab for a detection is electrically connected.
According to this prior art, it is said that by combining two bipolar secondary batteries having different characteristics and a general battery group in parallel, it is possible to efficiently achieve both high output and energy performance.

Japanese Patent Laid-Open No. 2005-97015

  However, in the prior art, the high power density type secondary battery generates heat during the output of the high power density type secondary battery such as a bipolar secondary battery and the high energy density type secondary battery such as a general battery. Since it is easy, it is difficult to bring out high output performance unless the high output density type secondary battery is cooled, but this is not mentioned. In particular, when a high power density type secondary battery and a high energy density type secondary battery are individually output, for example, in an electric vehicle or a hybrid vehicle, the high power density type secondary battery is dedicated for acceleration, and the high energy density type secondary battery is used. When the secondary battery is exclusively used for cruise, it is difficult to sufficiently obtain high output performance (acceleration performance) unless the high power density secondary battery is cooled.

  This invention is made | formed in view of such a subject, and it aims at providing the battery pack which can cool an internal secondary battery.

According to the present invention, it comprises a plurality of high power density type secondary batteries, a plurality of high energy density type secondary batteries, and a case for accommodating these secondary batteries as an assembled battery. Provided is a battery pack having a suction port for taking in outside air and a discharge port for discharging internal air to the outside.
Furthermore, according to another viewpoint of this invention, the electric vehicle provided with the said battery and the motor electrically connected so that this battery pack can be charged / discharged is provided.

According to the battery pack of the present invention, the internal secondary battery can be cooled, so that the high output density type secondary battery can be cooled at the time of output to bring out the original high output performance.
Therefore, this battery pack can efficiently achieve both high output performance and high energy performance, and is particularly suitable for outputting a high output density type secondary battery and a high energy density type secondary battery individually. .

FIG. 1 is a perspective view showing Embodiment 1 of a battery pack according to the present invention. FIG. 2 is an explanatory view illustrating the inside of an electric vehicle as an installation location of various embodiments of the battery pack of the present invention. FIG. 3 is a plan view showing a state where the lid of the battery pack of Embodiment 1 is removed. 4 is a cross-sectional plan view showing a state in which the secondary battery is removed from the battery pack of Embodiment 1. FIG. FIG. 5 is a schematic cross-sectional view illustrating the flow of air sent into the battery pack according to the first embodiment. FIG. 6 is a schematic cross-sectional view illustrating the internal structure and air flow of the battery pack of Embodiment 2. FIG. 7 is a schematic plan sectional view for explaining the internal structure and air flow of the battery pack according to the third embodiment. FIG. 8 is a schematic plan sectional view for explaining the internal structure and air flow of the battery pack according to the fourth embodiment. FIG. 9 is a schematic plan sectional view for explaining the internal structure and air flow of the battery pack according to the fifth embodiment. FIG. 10 is a schematic plan sectional view for explaining the internal structure and air flow of the battery pack of Embodiment 6. FIG. 11 is a schematic plan sectional view for explaining the internal structure and air flow of the battery pack according to the seventh embodiment. FIG. 12 is a schematic plan sectional view for explaining the internal structure and air flow of the battery pack according to the eighth embodiment. FIG. 13 is a schematic plan cross-sectional view illustrating the internal structure and air flow of the battery pack of Embodiment 9. FIG. 14A is a schematic cross-sectional view illustrating the internal structure of the battery pack of Embodiment 10, and FIG. 14B is a schematic side cross-sectional view of this battery pack. FIG. 15A is an explanatory view for explaining the arrangement of the batteries in the battery pack of Embodiment 11, and FIG. 15B is a schematic side sectional view.

The battery pack of the present invention includes a plurality of high power density type secondary batteries, a plurality of high energy density type secondary batteries, and a case for accommodating these secondary batteries as an assembled battery.
Here, the high power density type secondary battery only needs to have high output characteristics capable of charging and discharging a large current in a shorter time than the high energy density type secondary battery, while the high energy density type secondary battery is It only needs to have a higher energy density (unit weight or larger capacity per unit volume) than a high-power density type secondary battery, and the constituent materials, structures, etc. of each type of secondary battery are not particularly limited. Absent. Further, it is needless to say that each type of secondary battery has a long life, high reliability and safety, a wide use temperature range, and low cost.
From such a viewpoint, in the present invention, as a preferable example, a high-power density specification lithium ion battery and a high energy density specification lithium ion battery can be used.

Furthermore, in this invention, it is preferable that the thickness of the positive electrode and negative electrode in a high power density type secondary battery is thinner than the thickness of the positive electrode and negative electrode in a high energy density type secondary battery. In other words, in order to obtain high output by lowering the internal resistance, the active material layers of the positive electrode and negative electrode of the high power density type secondary battery are formed thin, on the contrary, the positive electrode and negative electrode of the high energy density type secondary battery are formed. The active material layer is formed thick.
Specifically, in the secondary battery, the characteristic change depending on the thickness of the positive electrode and the negative electrode mainly relates to the thickness of the positive electrode active material layer and the negative electrode active material layer. When the active material layer is thick, the ratio of the active material layer to the unit volume of the battery is increased, so that many reactions occur and the exchange of electrons increases and energy density is improved. On the other hand, since the part where the distance from the reaction site in the active material layer to the current collector increases, the resistance component also increases, which is not suitable for improving the output. On the other hand, when the active material layer is thin, it is the reverse of the above and the output can be improved by reducing the resistance component, but the energy density is improved because the ratio of the active material layer to the unit volume of the battery is reduced. It is unsuitable for making it happen.
Therefore, in the present invention, it is suitable for improving the function of each secondary battery that the thicknesses of the positive and negative electrodes of the high output and high energy density type secondary battery are as described above.

Further, in order to improve the cooling efficiency, the shape of the high power density secondary battery may be a flat type. Thereby, since the surface area of the high power density type secondary battery is increased, the contact area with the outside air of the high power density type secondary battery is increased, and the cooling effect can be enhanced. Flat type high power density type secondary batteries include a laminate of a plurality of positive and negative electrodes inserted into a rectangular metal can, or an aluminum laminate as an exterior made up of a plurality of resin layers and metal layers What was enclosed with the film can be used. Alternatively, a plate obtained by winding a single positive electrode and a single negative electrode into a flat plate shape and inserting it into a metal can or the like may be used.
On the other hand, in order to improve energy density, the shape of the high energy density secondary battery may be cylindrical. In this case, a cylindrical metal sheath can be used.

In the battery pack of the present invention, the case has an intake port for taking outside air into the inside and a discharge port for discharging internal air to the outside.
In addition, since this battery pack does not have a means for supplying outside air into the case, a separate means or method for supplying outside air into the case is required. For example, if this pack battery is used as a drive power source for an electric vehicle such as an electric vehicle or a hybrid vehicle including a passenger car, a bus, a truck, etc., a battery-powered streetcar, etc., the outside air naturally inhales by the movement of the electric vehicle. This is advantageous because it can be discharged from the outlet through the inside through the outlet. Therefore, this battery pack is suitable as a drive power source for an electric vehicle.

The battery pack of the present invention is preferably capable of efficiently cooling a high power density secondary battery that easily generates heat, in order to achieve both the performance of the high power density secondary battery and the performance of the high energy density secondary battery.
From such a viewpoint, the battery pack of the present invention may be configured as the following (1) to (5).

(1) In the case, each secondary battery is cooled such that the plurality of high power density type secondary batteries are cooled more efficiently than the plurality of high energy density type secondary batteries by outside air flowing into the inside from the suction port. Has a holding structure portion that can be arranged and held. In other words, the holding structure unit allows the secondary batteries to be arranged such that the degree of contact of the airflow in the case with each high power density type secondary battery is higher than the degree of contact with each high energy density type secondary battery. It has a structure to arrange. This structure is not particularly limited, and specifically includes the following structures.

(2) The holding structure has a structure in which the plurality of high power density secondary batteries are arranged sparsely and the plurality of high energy density secondary batteries are arranged densely. Thereby, a clearance gap can be formed between high power density type secondary batteries, and each high power density type secondary battery can be cooled efficiently by circulating external air through the gap.

(3) The holding structure section includes a first installation area in which a plurality of high power density secondary batteries are installed and a second installation area in which the plurality of high energy density secondary batteries are installed, The first installation area is wider than the second installation area. In this case, the degree of freedom in layout of the plurality of high-power density secondary batteries can be increased so that outside air can be efficiently contacted. In particular, it is particularly advantageous when the total installation area of a plurality of high power density secondary batteries and the total installation area of a plurality of high energy density secondary batteries are approximately the same. The cooling effect can also be enhanced.

(4) The holding structure has a structure in which a plurality of high-power density secondary batteries are arranged in a non-contact state. That is, more gaps are formed between the high power density type secondary batteries to increase the contact area with the outside air of each high power density type secondary battery to enhance the cooling effect.
(5) The holding structure has a structure in which a plurality of high-power density secondary batteries are arranged so that air in the case advances in a meandering manner from the inlet to the outlet. That is, a plurality of high power density secondary batteries form a long outside air flow path from the inlet to the outlet in the case, thereby enhancing the cooling effect of the high energy density secondary battery.
In this case, the holding structure section has a structure in which a plurality of high power density type secondary batteries are arranged in parallel to each other, or a plurality of high power density type secondary batteries are arranged in a waveform. In this way, there is an advantage that a compact case with a short distance from the inlet to the outlet can be used.

These structures (2) to (5) may be appropriately combined, and at least one of these structures is incorporated in various embodiments described later.
Hereinafter, various embodiments of the battery pack of the present invention will be described in detail with reference to the drawings.
(Embodiment 1)
1 is a perspective view showing Embodiment 1 of a battery pack according to the present invention, FIG. 2 is an explanatory view illustrating the inside of an electric vehicle as an installation place of various embodiments of the battery pack according to the present invention, and FIG. FIG. 4 is a plan view showing a state in which the lid of the battery pack of Embodiment 1 is removed, FIG. 4 is a plan sectional view showing a state in which the secondary battery is removed from the battery pack of Embodiment 1, and FIG. It is a schematic plane sectional view explaining the flow of the air sent in in the battery pack.

The battery pack P1 includes a plurality of high power density type secondary batteries Bp, a plurality of high energy density type secondary batteries Be, and a case E1 that accommodates these secondary batteries as an assembled battery. In the case of the first embodiment, the case E1 accommodates twelve high power density type secondary batteries Bp formed in a flat shape and twelve high energy density type secondary batteries Be formed in a cylindrical shape. It is configured.
Hereinafter, the high output density type secondary battery Bp may be referred to as “high output battery Bp” or “battery Bp”, and the high energy density type secondary battery Be may be referred to as “high energy battery Be” or “battery Be”.

  The case E1 includes a rectangular upper opening container-shaped case main body 10 and a plate-like lid 20 that closes the upper opening of the case main body 10. In addition, screw holes 12a are formed at the four corners of the upper opening of the case body 10, and through holes through which the screws 2 are inserted are formed at the four corners of the lid 20, and the screws 2 are inserted into the screw holes 12a. The lid 20 can be attached to and detached from the case body 10 by attaching and detaching.

The case body 10 includes a bottom wall 11, a peripheral wall 12 that constitutes front, rear, left and right walls, a suction port 13 that is formed in the front wall of the peripheral wall 12 and takes outside air into the interior, and a rear wall 12. Each high-power battery Bp is disposed so that the air outlet 14 formed on the wall and exhausts the internal air to the outside, and the outside air flowing into the interior from the inlet 13 efficiently contacts the plurality of high-power batteries Bp. And a holding structure 15 for holding.
1 and 3 to 5, the front-rear direction (length direction) and the left-right direction (width direction) of the battery pack P <b> 1 are indicated by arrows X and Y.

As shown in FIG. 2, the battery pack P1 is mounted on an electric vehicle C such as an electric vehicle or a hybrid vehicle.
In this case, in the electric vehicle C, for example, a battery storage space c1 in which the battery pack P1 is installed is formed under the floor of a seat or a trunk, and outside air is introduced into the battery storage space c1 during traveling and flows from the front to the rear. It is configured as follows. Accordingly, the suction port 13 of the battery pack P1 is directed to the front of the battery storage space c1, and the discharge port 14 is directed to the rear.
In addition, the electric vehicle C includes a motor (not shown) that converts the electric energy of the battery pack P1 into the rotational energy of the tire. The electric vehicle C may include a power storage system, and may be configured to charge the power storage system by converting the rotational energy of tires into electric energy using the motor as a generator during braking. A part or all of the battery pack P1 may be configured.

Case body 10 has a first installation area 10a ₁ for installing a plurality of high-power batteries Bp, and a second setting region 10a ₂ to install a plurality of high energy battery Be inside the case of the embodiment 1, The first installation area 10a ₁ is arranged in the center in the left-right direction Y and extends from the suction port 13 to the discharge port 14, and the second installation area 10a ₂ is arranged on both the left and right sides of the first installation area 10a ₁ . The second setting region 10a ₂ to the holding structure 15 of the first installation region 10a ₁ and the right side of the center thereof.
In the case of the first embodiment, the plurality of flat high-power batteries Bp are arranged in the first installation region 10a ₁ so that the air flowing into the case E1 from the suction port 13 proceeds in a meandering manner toward the discharge port 14. The plurality of high energy batteries Be are arranged in a row in the X direction in the left and right second installation regions 10a ₂ .

The holding structure portion 15 has a function of holding and positioning the plurality of high-power batteries Bp and the plurality of high-energy batteries Be arranged in the case body 10 as described above in an upright state. In other words, the holding structure 15 includes the recesses 15a that can be fitted with the lower ends of the high-power batteries Bp and the high-power batteries Bp and the high-energy batteries Be that are arranged as described above in the upright state. It has a recess 15b that can be fitted to the lower end of the high energy battery Be.
The recesses 15a and 15b are formed in a predetermined pattern on the bottom wall 11 of the case body 10 and have a first step portion 11a that comes into contact with the lower end surfaces of the batteries Bp and Be, and are higher than the first step portion 11a. The second step portion 11b is formed in a pattern and is in contact with the side surface of each battery Bp, Be.

The high-power battery Bp is held in an upright state by being fitted into a pair of U-shaped concave portions 15a in plan view that are spaced apart and arranged on the left and right.
The high energy battery Be is held in an upright state by being fitted into one circular recess of the recess 15b having a shape in which a plurality of circles are connected in a plan view.
The arrangement of the plurality of batteries Bp and Be is such that a pair of comb teeth are meshed with a gap. Further, the position of each high-energy battery Be on the left corresponds to each high-power battery Bp on the left, and the position of each high-energy battery Be on the right corresponds to each high-power battery Bp on the right. Therefore, the ventilation path A1 in the battery pack P1 is formed in a meandering shape from the inlet 13 toward the outlet 14.

A gap is formed between each battery Bp, Be installed in each recess 15a, 15b and the bottom wall 11. For example, when the electrodes are provided at the upper and lower ends of each battery 15a, 15b, the upper and lower electrodes are electrically connected to a lead wire (not shown) for taking out power, so the gap is not connected to the lead wire. Can be used as a space to pass through. In addition, a buffer member (for example, a sponge) is attached to the inner surface (lower surface) of the lid 20 so as to be in contact with the upper ends of the batteries 15a and 15b held at predetermined positions and to prevent the batteries 15a and 15b from wobbling. Therefore, the lead wire connected to the electrode at the upper end of each battery 15a, 15b can pass under the buffer member. An insertion hole (not shown) for drawing a lead wire into the case body 10 is formed at a predetermined location on the peripheral wall 12 of the case body 10.
Therefore, when the batteries 15 a and 15 b having electrodes at such opposed positions are not used, the lead wire can be passed over the battery, so that the holding structure portion 15 is brought into contact with the bottom wall 11. May be configured.

According to the battery pack P1 configured in this way, as shown in FIG. 5, the air flowing into the inside from the suction port 13 passes through the meandering air passage A1 formed by the batteries Bp and Be. It is discharged from the discharge port 14 to the outside. In FIG. 5, arrows indicate the air flow.
Thereby, in the battery pack P1, air flows in a meandering manner along both side surfaces (front surface and rear surface) of each high-power battery Bp. On the other hand, since almost no air flows between the plurality of high energy batteries Be arranged in one row on each of the left and right sides and the peripheral wall 12 of the case body 10, each high energy battery Be is a portion facing the ventilation path A1. Mainly the air flow contacts.

Thus, according to the battery pack p1 of the present invention, the high-power battery Bp that generates heat more easily than the high-energy battery Be can be efficiently air-cooled.
Further, in the battery pack P1, the plurality of high-power batteries Bp are arranged in a non-contact state with each other, so that a large number of gaps are formed between them, which is also the cooling effect of the high-power battery Bp. Is increasing.
Further, in the battery pack P1, the plurality of flat high-power batteries Bp are arranged in parallel to the Y direction and the batteries Bp are arranged in parallel to each other, so that the length in the X direction and the width in the Y direction are reduced. A compact battery pack P1 containing the high-power battery Bp can be obtained.

  In addition, the electrical connection form of the plurality of high-power batteries Bp, the electrical connection form of the plurality of high-energy batteries Be, and the electrical connection form of the group of the high-power batteries Bp and the group of the high-energy batteries Be particularly Without being limited, a desired connection form can be adopted. For example, a group of left-side high-power batteries Bp is connected in series, a group of right-side high-power batteries Bp is connected in series, a group of left-side high-energy batteries Be is connected in series, and a group of right-side high-energy batteries Be is connected. The left and right high power batteries Bp are connected in series, and the left and right high energy batteries Be are connected in parallel.

(Embodiment 2)
FIG. 6 is a schematic cross-sectional view illustrating the internal structure and air flow of the battery pack of Embodiment 2. In FIG. 6, the same elements as those in the first embodiment are denoted by the same reference numerals. Moreover, the arrow in the battery pack P2 in FIG. 6 has shown the flow of air.
The battery pack P2 of the second embodiment is substantially the same as that of the first embodiment except that the arrangement of the plurality of high-power batteries Bp and the holding structure that holds them are different. Hereinafter, the points of the second embodiment different from the first embodiment will be mainly described.
In the case E1 of the battery pack P2, a plurality of high-power batteries Bp are arranged in a plan view waveform (specifically, a sawtooth shape), and a group of high-energy batteries Be arranged in a line on the left and right sides. Ventilation paths A21 and A22 are formed between the group of corrugated high-power batteries Bp. The high-power battery Bp closest to the suction port 13 is disposed obliquely with respect to the X direction, and the adjacent high-power battery Bp is disposed perpendicular to the X direction, and this is repeated to form a waveform. ing.

  The holding structure (not shown) in the second embodiment is the same as the holding structure 15 described in the first embodiment, except that the pattern of the recesses is changed so as to hold the group of corrugated high-power batteries Bp in an upright state. is there. In the third to ninth embodiments to be described later, the description of the holding structure portion is omitted, but the third to ninth embodiments also have a holding structure portion that holds each secondary battery in an upright state with a different arrangement from the first embodiment. is doing.

According to the battery pack P2 configured in this way, as shown in FIG. 6, most of the air flowing into the inside from the suction port 13 flows along the side surface of the high-power battery Bp closest to the suction port 13. Then, it flows into one ventilation path A21 and is discharged to the outside through the discharge port 14. At this time, air flows through the ventilation path A21, so that an air vortex is generated in the valley space of the ventilation path A21, and the side surface of the high-power battery Bp facing the valley space is cooled.
Further, since air also flows into the airflow path A22 on the opposite side, air vortex flow is generated in the valley space of the airflow path A22, and the side surface on the opposite side of the high-power battery Bp is cooled.
In this way, the plurality of high-power batteries Bp are cooled more efficiently than the plurality of high-energy batteries Be.

(Embodiment 3)
FIG. 7 is a schematic plan sectional view for explaining the internal structure and air flow of the battery pack according to the third embodiment. In FIG. 7, the same reference numerals are given to the same elements as those in the first embodiment.
In the battery pack P3 of the third embodiment, a corrugated air passage A3 is formed in the case E1 from the inlet 13 to the outlet 14. That is, in order to form the corrugated ventilation path A3, a plurality of high-power batteries Bp are arranged in a waveform on the left and right sides of the ventilation path A3.
The plurality of high-energy batteries Be are arranged along the side surface opposite to the ventilation path A3 of the group of corrugated high-power batteries Bp.

According to the battery pack P3 configured in this way, as shown in FIG. 7, the air that has flowed into the interior from the suction port 13 is discharged to the outside through the corrugated ventilation path A3. At this time, each high-power battery Bp is cooled by the air coming into contact with the side surface of each high-power battery Bp facing the ventilation path A3. On the other hand, almost no air flows between the corrugated group of high-energy batteries Be and the surrounding wall of the case body 210.
In this way, the plurality of high-power batteries Bp are cooled more efficiently than the plurality of high-energy batteries Be.
In the case of the third embodiment, the high energy battery Be may be further arranged in a space between the group of corrugated high energy batteries Be and the peripheral wall of the case E1.

(Embodiment 4)
FIG. 8 is a schematic plan sectional view for explaining the internal structure and air flow of the battery pack according to the fourth embodiment. In FIG. 8, the same elements as those in the first embodiment are denoted by the same reference numerals.
In the battery pack P4 of the third embodiment, a group of high-energy batteries Be is arranged in two rows in the center in the Y direction in the case E1 and in the region extending from the suction port 13 to the discharge port 14 (second installation region). The group of high-power batteries Bp is arranged in the left and right regions (first installation region) of the group of energy batteries Be. And ventilation path A41, A42 is formed between the group of right-and-left high output batteries Bp and the surrounding wall of case E1.
FIG. 8 illustrates a case where six high energy batteries Be are arranged in each row, and each high output battery Bp is arranged at a position corresponding to each high energy battery Be.

According to the battery pack P4 configured in this manner, as shown in FIG. 8, the air that has flowed into the inside from the suction port 13 is discharged to the outside through the left and right ventilation paths A41, A42. At this time, since an air eddy current is generated in the space between the high-power batteries Bp, the side surfaces of the high-power batteries Bp are cooled. On the other hand, since there is no gap between the high energy batteries Be and between the high energy battery Be and the high output battery Bp, no air flows between them.
In this way, the plurality of high-power batteries Bp are cooled more efficiently than the plurality of high-energy batteries Be.

(Embodiment 5)
FIG. 9 is a schematic plan sectional view for explaining the internal structure and air flow of the battery pack according to the fifth embodiment. In FIG. 9, the same elements as those in the first embodiment are denoted by the same reference numerals.
In the first to fourth embodiments, the first installation region 10a _{1 where} the plurality of high-power batteries Bp are installed, the suction port 13 and the discharge port 14 are disposed at the center position in the Y direction of the case E1. On the other hand, in the fifth embodiment, the first installation region 110a ₁ , the suction port 113, and the discharge port 114 in which the plurality of high-power batteries Bp are installed are arranged on one end side in the Y direction of the case E2, and A second installation region 110a _{2 in} which the energy battery Be is installed is arranged on the other end side in the Y direction. In addition, about these points, the below-mentioned Embodiments 6 and 7 are also the same.

In the battery pack P5 of the fifth embodiment, the plurality of high-power batteries Bp are alternately shifted in the same manner as in the first embodiment and arranged in the first installation region 110a ₁ to form a meandering ventilation path A51. .
Further, the plurality of high energy batteries Be are arranged in two rows in the second installation region 110a ₂ and close to the plurality of high power batteries Bp.
According to the battery pack P5 configured as described above, as shown in FIG. 9, the air flowing into the inside from the suction port 113 is discharged to the outside through the meandering air passage A51 and from the discharge port 114. At this time, the plurality of high-power batteries Bp are cooled more efficiently than the plurality of high-energy batteries Be.

(Embodiment 6)
FIG. 10 is a schematic plan sectional view for explaining the internal structure and air flow of the battery pack of Embodiment 6. In FIG. 10, the same elements as those in the first and fifth embodiments are denoted by the same reference numerals.
In the battery pack P6 of the sixth embodiment, the plurality of high-power batteries Bp are arranged in the first installation region 110a ₁ in a waveform similar to the second embodiment. The plurality of high energy batteries Be are arranged in two rows in the second installation region 110a ₂ as in the fifth embodiment.
According to the battery pack P6 configured as described above, as in the second embodiment, the air flows through the ventilation paths A61 and A62 formed on both sides of the group of the plurality of high-power batteries Bp, so that the plurality of high-energy batteries A plurality of high-power batteries Bp are cooled more efficiently than Be.

(Embodiment 7)
FIG. 11 is a schematic plan sectional view for explaining the internal structure and air flow of the battery pack according to the seventh embodiment. In FIG. 11, elements similar to those in the first and fifth embodiments are denoted by the same reference numerals.
In the battery pack P7 of the seventh embodiment, the plurality of high-power batteries Bp are arranged in the first installation area 110a ₁ in a waveform similar to the third embodiment. Further, the plurality of high energy batteries Be are also arranged along the side surface on the second installation region 110a ₂ side of each high power battery Bp as in the third embodiment.
According to the battery pack P7 configured as described above, air flows through the ventilation path A71 formed on one side of the group of the plurality of high-power batteries Bp, so that the plurality of high-power batteries Bp is more than the plurality of high-energy batteries Be. Cool efficiently.

(Embodiment 8)
FIG. 12 is a schematic plan sectional view for explaining the internal structure and air flow of the battery pack according to the eighth embodiment. In FIG. 12, the same elements as those in the first embodiment are denoted by the same reference numerals.
In the eighth embodiment, the suction port 213 is disposed at the center position in the Y direction of the case E3, and the discharge port 214 is disposed on one end side. Further, the first installation area 210a ₁ is arranged in the range from the suction port 213 to the discharge port 214 in the case E3, and the second installation area 210a ₂ is arranged in the remaining range in the case E3. These points are the same as in the ninth embodiment described later.

Further, the plurality of high energy batteries Be are arranged in parallel in a plurality of rows in an oblique direction from the inlet 213 to the outlet 214, and the plurality of high energy batteries Be are in the second installation region 210a ₂ as in the fifth embodiment. Are arranged in two rows. In this case, in one row of high energy batteries Be, there is no gap between the two high energy batteries Be adjacent in the oblique direction.
According to the battery pack P8 configured as described above, air flows through the ventilation paths A81, A83 on both sides in the X direction of the group of the plurality of high output batteries Bp and the ventilation path A82 between the rows of the adjacent high output batteries Bp. Thus, the plurality of high-power batteries Bp are cooled more efficiently than the plurality of high-energy batteries Be.

(Embodiment 9)
FIG. 13 is a schematic plan cross-sectional view illustrating the internal structure and air flow of the battery pack of Embodiment 9. In FIG. 13, the same reference numerals are given to the same elements as those in the first and eighth embodiments.
The difference between the ninth embodiment and the eighth embodiment is that, in each row of high-energy batteries Be, a gap is formed between two high-energy batteries Be adjacent in the diagonal direction, and the first installation area 210a ₁ The high energy battery Be is also disposed in the dead space.
According to the battery pack P9 configured as described above, the ventilation path A91 is formed around each high-power battery Bp, so that the plurality of high-power batteries Bp are more efficiently cooled than the plurality of high-energy batteries Be. be able to.

(Embodiment 10)
FIG. 14A is a schematic cross-sectional view illustrating the internal structure of the battery pack of Embodiment 10, and FIG. 14B is a schematic side cross-sectional view of this battery pack. In FIG. 14, the same elements as those in the first embodiment are denoted by the same reference numerals.
In Embodiments 1 to 9, the case where each secondary battery is held in an upright state by the holding structure portion in the case is illustrated. On the other hand, in the tenth embodiment, the case E4 is formed in a flat box shape, and each secondary battery is housed in a lying state in the case E4.

More specifically, the case E4 has a suction port 313 and a discharge port 314 that are long in the Y direction at the upper part of both ends in the X direction on the peripheral wall. In addition, no holding structure is provided in the case E4. A plurality of high energy batteries Be are laid down in the lower part of the case E4, and a plurality of high power batteries Bp are laid down on the plurality of high energy batteries Be.
According to the battery pack P10 configured in this way, the ventilation path A101 is formed on each high-power battery Bp, so that the plurality of high-power batteries Bp are more efficiently cooled than the plurality of high-energy batteries Be. be able to. Moreover, since this battery pack 10 is thin, it is suitable for installation under the floor of an electric vehicle, for example.

(Embodiment 11)
FIG. 15A is an explanatory view for explaining the arrangement of the batteries in the battery pack of Embodiment 11, and FIG. 15B is a schematic side sectional view. In FIG. 15, the same elements as those in the first embodiment are denoted by the same reference numerals.
The case E5 of the battery pack P11 is formed in a shape that can be installed from the lower part of the rear seat of the electric vehicle along the rear part, for example.
More specifically, the case E5 includes a first storage portion 410A and a first storage portion 410 that are formed so that a plurality of high energy batteries Be can be laid down in a plurality of upper and lower stages (or one stage). And a second storage portion 410B formed so that a plurality of high-power batteries Bp can be arranged in a wall shape. The first storage unit 410A is installed along the lower portion of the rear seat, and the second storage unit 410B is installed along the rear part of the rear seat.

Further, in the case E5, a suction port 413 is provided in the upper portion of the front wall in the X direction of the first storage portion 410A, and a discharge port 414 is provided in the lower portion of the rear wall of the second storage portion 410B in the X direction. . A ventilation path A111 is formed above the group of the plurality of high energy batteries Be in the first storage unit 410A and on the front, top, and rear of the group of the plurality of high output batteries Bp in the second storage unit 410B. Yes.
According to the battery pack P11 configured in this way, the plurality of high-power batteries Bp arranged in a wall shape are both exposed to the ventilation path A111, and thus more efficient than the plurality of high-energy batteries Be. Can be cooled. In addition, as a method of holding the plurality of high-power batteries Bp in a wall shape, for example, a method of surrounding them with a wire mesh and holding them so as not to lose their shape can be mentioned.

Bp High power density type secondary power (high power battery)
Be High energy density type secondary battery (high energy battery)
E1 to E5 Case 13, 113, 213, 313, 413 Suction port 14, 114, 214, 314, 414 Discharge port 15 Holding structure 10a ₁ First installation area 10a ₂ Second installation area P1 to P11 Pack battery

Claims (11)

  A plurality of high power density type secondary batteries, a plurality of high energy density type secondary batteries, and a case for accommodating these secondary batteries as an assembled battery, wherein the case is an intake for taking outside air into the inside. A battery pack comprising a mouth and a discharge port for discharging the internal air to the outside.   The case arranges each secondary battery so that the plurality of high power density type secondary batteries are cooled more efficiently than the plurality of high energy density type secondary batteries by outside air flowing into the inside from the suction port. The battery pack according to claim 1, further comprising a holding structure that can hold the battery pack.   The battery pack according to claim 1 or 2, wherein a thickness of the positive electrode and the negative electrode in the high power density type secondary battery is thinner than a thickness of the positive electrode and the negative electrode in the high energy density type secondary battery.   The battery pack according to any one of claims 1 to 3, wherein a shape of the high power density type secondary battery is a flat type and a shape of the high energy density type secondary battery is a cylindrical type.   The holding structure has a structure in which the plurality of high power density type secondary batteries are arranged sparsely and the plurality of high energy density type secondary batteries are arranged densely. The battery pack described.   The holding structure includes a first installation area in which the plurality of high power density type secondary batteries are installed and a second installation area in which the plurality of high energy density type secondary batteries are installed. The battery pack according to any one of claims 1 to 5, wherein an installation area is wider than the second installation area.   The battery pack according to any one of claims 1 to 6, wherein the holding structure has a structure in which a plurality of high-power density secondary batteries are arranged in a non-contact state with each other.   The holding structure has a structure in which a plurality of high-power density secondary batteries are arranged so that air in the case advances in a meandering manner from the inlet to the outlet. The battery pack described.   The battery pack according to claim 8, wherein the plurality of high power density secondary batteries are arranged in parallel to each other.   The battery pack according to claim 8, wherein the plurality of high power density secondary batteries are arranged in a waveform.   An electric vehicle comprising: the battery pack according to any one of claims 1 to 10; and a motor that converts electric energy of the battery pack into driving energy.

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