JP2020177748A - Vehicular battery pack - Google Patents

Abstract

To provide a vehicular battery pack capable of improving a flow of a fluid member in the inside of a housing storing a plurality of batteries.SOLUTION: A vehicular battery pack 1 includes a housing 2, a plurality of batteries 3 aligned at intervals in a horizontal direction orthogonal to a vertical direction in an inner space 2a of the housing 2, a fluid member 4 that has heat conductivity, and is collected in the inner space 2a of the housing 2, and a platy member 5 formed in the vertical direction. The platy member 5 is disposed separately in a vertical direction from an inner upper surface 2d and an inner bottom surface 2b of the housing 2. The fluid member 4 fills the inner space 2a so that upper ends in the vertical direction of the battery 3 and the platy member 5 are submerged. The platy member 5 is disposed between an inner side surface 2c of the housing 2 and the battery 3 adjacent to the inner side surface 2c of the housing 2, in the inner space 2a viewed from the vertical direction.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicle battery pack.

Vehicles such as electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid vehicles (PHEVs) are equipped with, for example, a battery pack as a power source for supplying electric power for driving a motor as a drive source. The battery pack contains a plurality of batteries (secondary batteries), and each battery is electrically connected in series and / or in parallel. The usable temperature of each battery is determined because the temperature changes during charging and discharging and the temperature rises according to the traveling time of the vehicle. Therefore, if the usable temperature is exceeded due to a high load applied to each battery in a short time, the storage deterioration and cycle deterioration of each battery will be accelerated, so the cooling function is provided for the purpose of keeping the battery within the usable temperature. It may be carried in the battery pack.

For example, it is provided with a heat conductive housing, a plurality of batteries arranged in a direction orthogonal to the vertical direction in the internal space of the housing, and a fluidizing member having thermal conductivity and heat storage. However, there is disclosed a vehicle battery pack that is accommodated while leaving the internal space of the housing and covers at least a part of each battery (see Patent Document 1). Further, in a liquid electrolyte battery having a liquid electrolyte circulation device, a pair of electrode plates arranged vertically in the cell and a liquid electric field in which the water level in the cell reaches above the upper corner of the electrode are provided, and the liquid electrolyte circulation device is provided. Discloses that it has a vertical flow channel formed between the wall of the case and the electrode plate (see Patent Document 2).

Japanese Unexamined Patent Publication No. 2018-37159 Special Table 2001-506055

By the way, in the above-mentioned conventional technique, when a battery generates heat in a state where the battery is densely packed in a closed space, a fluid member around the battery flows upward by natural convection. However, in a closed space, the upwardly flowing fluid member loses its place, so that the pressure of the fluid member staying on the upper part of the battery increases, and the fluid member creates a relatively large space around the battery group. It is pushed through to the bottom of the low pressure battery. At that time, the upward flow and the downward flow are mixed in the path through which the fluid member flows, and the downward flow is obstructed. Due to this flow obstruction, the flow rate of the fluid member reaching the lower part of the battery decreases, so that the overall flow velocity decreases and the cooling capacity of the entire battery decreases, so there is room for improvement.

An object of the present invention is to provide a vehicle battery pack capable of improving the flow of fluid members inside a housing that accommodates a plurality of batteries.

In order to achieve the above object, the vehicle battery pack according to the present invention includes a housing, a plurality of batteries arranged apart from each other in the horizontal direction orthogonal to the vertical direction in the internal space of the housing, and heat conduction. A fluid member having a property and being stored in the internal space of the housing and a plate-shaped member formed along the vertical direction are provided, and the plate-shaped member includes an inner upper surface and an inner bottom surface of the housing. The fluidizing member fills the internal space so that the upper end of the battery and the plate-shaped member in the vertical direction is immersed therein, and the plate-shaped member is viewed from the vertical direction. It is characterized in that it is arranged between the inner side surface of the housing and the battery adjacent to the inner side surface of the housing in the internal space.

In the vehicle battery pack, the plate-shaped member is arranged between the inner side surface of the housing and the battery adjacent to the inner side surface of the housing in the internal space viewed from the vertical direction, and It is formed so as to surround the plurality of the batteries.

In the vehicle battery pack, the plurality of the batteries are arranged vertically separated from the inner upper surface and the inner bottom surface of the housing, and the plate-shaped members are arranged vertically in the arranged state arranged in the internal space. The lower end in the direction is located between the bottom surface of the battery and the inner bottom surface of the housing.

In the vehicle battery pack, the plurality of the batteries are arranged vertically separated from the inner upper surface and the inner bottom surface of the housing, and the plate-shaped members are arranged vertically in the arranged state arranged in the internal space. The upper end in the direction is located between the upper surface of the battery and the inner upper surface of the housing.

According to the vehicle battery pack in the present invention, there is an effect that the flow of the fluid member inside the housing for accommodating a plurality of batteries can be improved.

FIG. 1 is a perspective view showing a schematic configuration of a vehicle battery pack according to an embodiment. FIG. 2 is a top view showing a schematic configuration of the vehicle battery pack according to the embodiment. FIG. 3 is a schematic view showing a schematic configuration of a vehicle battery pack according to an embodiment. FIG. 4 is a partial top view showing a schematic configuration of a vehicle battery pack according to a first modification of the embodiment. FIG. 5 is a partial top view showing a schematic configuration of a vehicle battery pack according to a second modification of the embodiment.

The vehicle battery pack according to the embodiment of the present invention will be described in detail below with reference to the drawings. The present invention is not limited to the following embodiments. In addition, the components in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same. In addition, the configurations described below can be combined as appropriate.

[Embodiment]
The vehicle battery pack according to the embodiment of the present invention will be described with reference to FIGS. 1 to 3. FIG. 1 is a perspective view showing a schematic configuration of a vehicle battery pack according to an embodiment. FIG. 2 is a top view showing a schematic configuration of the vehicle battery pack according to the embodiment. FIG. 3 is a schematic view showing a schematic configuration of a vehicle battery pack according to an embodiment. Note that FIGS. 1 and 2 (also in FIGS. 4 and 5) show a state in which the lid (not shown) of the battery pack housing is removed to expose the inside to the outside. FIG. 3 shows the flow of the fluid member inside the housing of the battery pack.

Here, in the following description, the illustrated X direction is the width direction of the vehicle battery pack according to the present embodiment. The Y direction is the depth direction of the vehicle battery pack in the present embodiment, and is a direction orthogonal to the width direction. The Z direction is the vertical direction of the vehicle battery pack in the present embodiment, and is a direction orthogonal to the width direction and the depth direction.

The vehicle battery pack 1 according to the present embodiment is mounted on a vehicle (not shown) such as an electric vehicle (EV), a hybrid vehicle (HEV), or a plug-in hybrid vehicle (PHEV), and is used for traveling of the vehicle. A secondary battery that supplies power to a drive source (not shown). As shown in FIGS. 1 and 2, the vehicle battery pack 1 includes a housing 2, a plurality of batteries 3, a fluidity member 4, and a plate-shaped member 5.

The housing 2 accommodates a plurality of batteries 3, a fluidizing member 4, and a plate-shaped member 5. The housing 2 is provided in a vehicle, for example, at a place where the outer surface of the housing 2 can come into contact with the outside air taken in from the outside of the vehicle. The housing 2 is formed in a box shape and has an internal space 2a inside. The internal space 2a is filled with a fluid member 4 in which a plurality of batteries 3 and a plate-shaped member 5 are arranged. The housing 2 has at least thermal conductivity, and is made of, for example, iron, copper, aluminum, or the like. The housing 2 closes the internal space 2a with a lid (not shown). When the vehicle battery pack 1 is required to be waterproof, a waterproof structure is formed between the housing 2 and the lid to seal the internal space 2a.

The plurality of batteries 3 are arranged apart from each other in the horizontal direction orthogonal to the vertical direction in the internal space 2a of the housing 2. The plurality of batteries 3 are arranged in a staggered lattice or a square lattice at intervals in the horizontal direction orthogonal to the vertical direction in the internal space 2a, for example. The plurality of batteries 3 are held by holding members (not shown) or the like arranged in the housing 2, and are arranged vertically separated from the inner bottom surface 2b and the inner upper surface 2d of the housing 2. Among the plurality of batteries 3, the battery group adjacent to the inner side surface 2c of the housing 2 is arranged apart from the inner side surface 2c of the housing 2 by a holding member or the like. Each battery 3 is a cylindrical secondary battery extending along the vertical direction. Each battery 3 is composed of, for example, a lithium ion battery. The holding member may have any structure and configuration as long as the battery 3 can be arranged vertically separated from the inner upper surface 2d and the inner bottom surface 2b of the housing 2.

The fluid member 4 has thermal conductivity and is stored in the internal space 2a of the housing 2. As shown in FIG. 2, the fluid member 4 fills the internal space 2a so that the upper ends of the battery 3 and the plate-shaped member 5 in the vertical direction are immersed. The fluid member 4 is made of, for example, water, paraffin, fatty acid, sugar alcohol, inorganic salt hydrate, vanadium dioxide and the like. The fluidity member 4 of the present embodiment is stored so as to fill the entire internal space 2a of the housing 2, but is not limited thereto. For example, the fluid member 4 only needs to fill the internal space 2a so that the upper ends of the battery 3 and the plate-shaped member 5 in the vertical direction are immersed, and gas and liquid having a little gas under the inner upper surface 2d of the housing 2. It may be in a mixed state.

The plate-shaped member 5 is formed in a plate shape and extends along the vertical direction. The plate-shaped member 5 is formed with a constant thickness in the vertical direction. The plate-shaped member 5 is formed of, for example, a metal material such as stainless steel or an iron alloy. As shown in FIG. 3, the plate-shaped member 5 is arranged vertically separated from the inner upper surface 2d and the inner bottom surface 2b of the housing 2. In the arranged state of the plate-shaped member 5 arranged in the internal space 2a, the lower end in the vertical direction is located between the bottom surface 3b of the battery 3 and the inner bottom surface 2b of the housing 2. The lower end of the plate-shaped member 5 of the present embodiment is located at the same height as the bottom surface 3b of the battery 3. Further, in the arranged state in which the plate-shaped member 5 is arranged in the internal space 2a, the upper end in the vertical direction is located between the upper surface 3a of the battery 3 and the inner upper surface 2d of the housing 2. The upper end of the plate-shaped member 5 of the present embodiment is located at the same height as the upper surface 3a of the battery 3. The plate-shaped member 5 is arranged between the inner side surface 2c of the housing 2 and the battery 3 adjacent to the inner side surface 2c of the housing 2 in the internal space 2a viewed from the vertical direction. As shown in FIGS. 1 and 2, the plate-shaped member 5 of the present embodiment is a battery adjacent to the inner side surface 2c of the housing 2 and the inner side surface 2c of the housing 2 in the internal space 2a viewed from the vertical direction. It is arranged between the three batteries and is formed so as to surround the plurality of batteries 3.

In the plate-shaped member 5, the distance between the plate-shaped member 5 and the adjacent battery 3 is the same as the distance between the plurality of batteries 3. Specifically, when the distances between the plurality of batteries 3 are each distance P, the distance between the plate-shaped member 5 and the adjacent batteries 3 is the same distance P (FIG. 2). ). The distance between the plate-shaped member 5 and the inner side surface 2c of the housing 2 adjacent to the plate-shaped member 5 can be arbitrarily set, but it is used for space and tool work to cope with a collision. It is preferable to set in consideration of the space, target energy density, and the like.

Next, the flow of the fluidity member 4 in the vehicle battery pack 1 of the present embodiment will be described with reference to FIG. When the temperature of the fluid member 4 rises, the fluid molecules thermally expand and the specific gravity becomes lighter, and buoyancy is generated. Since this buoyancy acts in the direction opposite to gravity, the warmed fluid molecules move upward in the vertical direction. As a result, the fluidity members 4 staying on the upper side of the plurality of batteries 3 are in a state of high pressure due to the flow of fluid molecules toward the upper side. Liquids generally try to flow from high pressure to low pressure. Therefore, the fluid member 4 in a high pressure state passes between the inner side surface 2c of the housing 2 and the plate-shaped member 5, and flows to the lower side of the battery 3 having a low pressure. On the other hand, the fluid member 4 heated between the plate-shaped member 5 and the battery 3 adjacent to the plate-shaped member 5 flows toward the upper side of the battery 3. As a result, the mixture of the upward flow and the downward flow of the fluid member 4 around the plurality of batteries 3 is suppressed, and the flow of the fluid member 4 can be smoothly performed.

As described above, the vehicle battery pack 1 according to the present embodiment includes the housing 2 and a plurality of batteries 3 arranged apart from each other in the horizontal direction orthogonal to the vertical direction in the internal space 2a of the housing 2. A fluid member 4 having thermal conductivity and stored in the internal space 2a of the housing 2 and a plate-shaped member 5 formed along the vertical direction are provided. The plate-shaped member 5 is arranged vertically separated from the inner upper surface 2d and the inner bottom surface 2b of the housing 2. The fluid member 4 fills the internal space 2a so that the upper ends of the battery 3 and the plate-shaped member 5 in the vertical direction are immersed. The plate-shaped member 5 is arranged between the inner side surface 2c of the housing 2 and the battery 3 adjacent to the inner side surface 2c of the housing 2 in the internal space 2a viewed from the vertical direction.

With the above configuration, it is possible to improve the flow of the fluid member 4 inside the housing 2 that accommodates the plurality of batteries 3. Specifically, the fluid member 4 on the upper side of the battery 3 whose temperature has risen due to the heat generated by the battery 3 and whose pressure has increased descends between the inner side surface 2c of the housing 2 and the plate-shaped member 5. , It is pushed out to the lower side of the plurality of batteries 3. On the other hand, the fluid member 4 heated between the plate-shaped member 5 and the battery 3 adjacent to the plate-shaped member 5 flows toward the upper side of the battery 3. As a result, the mixture of the upward flow and the downward flow of the fluid member 4 around the plurality of batteries 3 is suppressed, the flow of the fluid member 4 can be smoothly performed, and the cooling capacity of the entire battery is reduced. Can be suppressed.

Further, in the vehicle battery pack 1 according to the present embodiment, the plate-shaped member 5 is adjacent to the inner side surface 2c of the housing 2 and the inner side surface 2c of the housing 2 in the internal space 2a viewed from the vertical direction. It is arranged between the three batteries and is formed so as to surround the plurality of batteries 3. As a result, as compared with the case where the plate-shaped member 4 is partially arranged around the plurality of batteries 3, the flow of the fluid member 4 can be smoothly performed, and the decrease in the cooling capacity of the entire battery is further suppressed. can do.

Further, in the vehicle battery pack 1 according to the present embodiment, a plurality of batteries 3 are arranged vertically separated from the inner upper surface 2d and the inner bottom surface 2b of the housing 2. As a result, the fluid member 4 can flow on the upper side and the lower side of the plurality of batteries 3, respectively, and the natural convection of the fluid member 4 can be promoted.

Further, in the vehicle battery pack 1 according to the present embodiment, in the arrangement state in which the plate-shaped member 5 is arranged in the internal space 2a, the lower end in the vertical direction is the bottom surface 3b of the battery 3 and the internal bottom surface 2b of the housing 2. Located between. As a result, the fluidizing member 4 toward the inner side surface 2c of the housing 2 along the inner upper surface 2d of the housing 2 becomes the inner side surface 2c of the housing 2 and the plate-shaped member 5 facing the inner side surface 2c. It is possible to guide the flow between them. Further, the fluidity member 4 heated by the battery 3 can be efficiently flowed to the upper side of the battery 3 between the plate-shaped member 5 and the battery 3 adjacent to the plate-shaped member 5.

Further, in the vehicle battery pack 1 according to the present embodiment, in the arrangement state in which the plate-shaped member 5 is arranged in the internal space 2a, the upper end in the vertical direction is the upper surface 3a of the battery 3 and the inner upper surface 2d of the housing 2. Located between. As a result, the fluid member 4 flowing downward in the vertical direction through between the inner side surface 2c of the housing 2 and the plate-shaped member 5 facing the inner side surface 2c is efficiently placed in the space below the battery 3. Can be fluidized well. Further, the fluidizing member 4 staying on the lower side of the battery 3 adjacent to the plate-shaped member 5 is guided to flow between the plate-shaped member 5 and the battery 3 adjacent to the plate-shaped member 5. Can be done.

In the above embodiment, as shown in FIGS. 1 and 2, the plate-shaped member 5 is arranged so as to surround all the batteries 3 arranged in the internal space 2a of the housing 2, but is limited to this. It's not something. FIG. 4 is a partial top view showing a schematic configuration of a vehicle battery pack according to a first modification of the embodiment. FIG. 5 is a partial top view showing a schematic configuration of a vehicle battery pack according to a second modification of the embodiment.

A plurality of plate-shaped members 5A shown in FIG. 4 are arranged between the internal side surface 2c of the housing 2 and the battery 3 adjacent to the internal side surface 2c of the housing 2 in the internal space 2a viewed from the vertical direction. It is arranged so as to be adjacent to a part of the battery 3. The plate-shaped member 5A of the present embodiment is arranged at a position facing one of the four (four sides) internal side surfaces 2c of the housing 2. The plate-shaped member 5A is arranged at a position facing one of the plurality of internal side surfaces 2c of the housing 2, but faces two adjacent internal side surfaces 2c among the plurality of internal side surfaces 2c. It may be arranged at a position. In this case, the plate-shaped member 5A is arranged between the inner side surface 2c of the housing 2 and the battery 3 adjacent to the inner side surface 2c of the housing 2 in the internal space 2a viewed from the vertical direction, and is adjacent to each other. It is formed so as to face the two internal side surfaces 2c.

The plate-shaped member 5B shown in FIG. 5 is arranged between the inner side surface 2c of the housing 2 and the battery 3 adjacent to the inner side surface 2c of the housing 2 in the internal space 2a viewed from the vertical direction, and is a plate. It is formed in an uneven shape in the horizontal direction according to the outer surface of the battery 3 adjacent to the shaped member 5B. The plate-shaped member 5B of the present embodiment has a wavy shape when viewed from the vertical direction in accordance with a plurality of cylindrical batteries 3.

In the plate-shaped members 5A and 5B, the distance between the plate-shaped members 5A and 5B and the adjacent batteries 3 is the same as the distance between the plurality of batteries 3. Specifically, when the distance between the plurality of batteries 3 is the distance P, the distance P between the plate-shaped members 5A and 5B and the adjacent batteries 3 and the plate-shaped members 5A and 5B is the same. Become.

In the above embodiment, the plate-shaped members 5, 5A and 5B are made of a metal material, but the present invention is not limited to this, and the plate-shaped members 5, 5A and 5B may be made of a synthetic resin or the like.

In the above embodiment, the plate-shaped members 5, 5A and 5B are formed with a constant thickness in the vertical direction, but the thickness is not limited thereto. For example, the thickness on the upper side in the vertical direction may be formed to be thinner than the thickness on the lower side, or vice versa.

In the above embodiment, the fluidity member 4 is a liquid having fluidity, but may be a gas.

1 Battery pack for vehicles 2 Housing 2a Internal space 2b Internal bottom surface 2c Internal side surface 2d Internal upper surface 3 Battery 3a Upper surface 3b Bottom surface 4 Fluid member 5, 5A, 5B Plate-shaped member

Claims (4)

With the housing
A plurality of batteries arranged at intervals in the horizontal direction orthogonal to the vertical direction in the internal space of the housing, and
A fluid member that has thermal conductivity and is stored in the internal space of the housing,
A plate-shaped member formed along the vertical direction,
With
The plate-shaped member is
Arranged vertically apart from the inner upper surface and the inner bottom surface of the housing,
The fluid member is
The internal space is filled so that the upper end of the battery and the plate-shaped member in the vertical direction is immersed.
The plate-shaped member is
A vehicle battery pack characterized in that it is arranged between the internal side surface of the housing and the battery adjacent to the internal side surface of the housing in the internal space viewed from the vertical direction. The plate-shaped member is
A claim that is arranged between the internal side surface of the housing and the battery adjacent to the internal side surface of the housing in the internal space viewed from the vertical direction, and is formed so as to surround the plurality of the batteries. The vehicle battery pack according to 1. The plurality of the batteries
Arranged vertically apart from the inner upper surface and the inner bottom surface of the housing,
The plate-shaped member is
The vehicle battery pack according to claim 1 or 2, wherein the lower end in the vertical direction is located between the bottom surface of the battery and the inner bottom surface of the housing in the arranged state arranged in the internal space. The plurality of the batteries
Arranged vertically apart from the inner upper surface and the inner bottom surface of the housing,
The plate-shaped member is
The vehicle battery pack according to any one of claims 1 to 3, wherein the upper end in the vertical direction is located between the upper surface of the battery and the inner upper surface of the housing in the arranged state arranged in the internal space. ..

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