WO2017101676A1

WO2017101676A1 - Cooling system used in battery pack and battery pack

Info

Publication number: WO2017101676A1
Application number: PCT/CN2016/107966
Authority: WO
Inventors: Sylvain Guenon
Original assignee: Bosch Automotive Products (Suzhou) Co., Ltd.
Priority date: 2015-12-15
Filing date: 2016-11-30
Publication date: 2017-06-22
Also published as: CN205211888U

Abstract

The present invention relates to a cooling system used in a battery pack (1), the battery pack (1) comprising a housing (2) for accommodating a plurality of battery cells (5) and at least one separation wall (3) for separating the battery cells (5) from each other in an electrically insulating manner, characterized in that the cooling system comprises at least one heat dissipating means (10), which is partially embedded in the housing (2) and/or the separation wall (3) such that at least one portion of the heat dissipating means (10) protrudes outwardly beyond the housing (2). The present invention further relates to a battery pack comprising the above cooling system. According to the present invention, the battery pack can dissipate the heat generated in the cells in a simpler and more compact manner compared to the prior fluid cooling systems.

Description

Cooling System Used in Battery Pack and Battery Pack

Technical Field

The invention relates to a cooling system used in a battery pack. The present invention further relates to a battery pack with such a cooling system.

Background Art

Battery packs are used to provide power in a wide variety of applications, for example automotive applications such as hybrid vehicle (HEVs) , electric vehicles (EVs) , heavy duty vehicles (HDVs) and the like. The lithium-ion battery is preferably used in the automotive application due to its high energy density compared with other battery technologies. However, the performances of the lithium-ion battery such as power, internal resistance and lifetime are strongly depending on the temperature. Accordingly, an efficient temperature management of the battery cells should be guaranteed during operation.

To this end, the battery pack is always provided with a cooling system for cooling the battery cells and maintaining the temperature of the battery cells in the optimal operation range. In general, the current cooling systems are typically configured such that the fluid cooling medium such as liquid or air can be guided through the battery pack to take away the heat generated in the cells. However, such cooling systems concern several problems.

In the case of liquid cooling medium, the incorporation of the cooling system leads to many additional components being arranged in both the battery pack and the vehicle, including but not limited to duct, pump, piping, heat exchanger, sealing means and other necessary components for circulating and cooling the liquid cooling medium. It results in great efforts and expense in manufacturing these components and the corresponding battery packs and substantially increased space and complexity for mounting the same.

In the case of air, the noise can be undesirably produced by a fan or blower for creating an air flow. Moreover, the feed of the air into the battery pack may simultaneously introduce humidity, dust and/or particles, which are potentially harmful to the components of the battery pack and thus result in the humidity resistant means having to be applied in the battery pack.

Accordingly, it’s desirable to provide a battery pack which doesn’t need the fluid cooling medium and thus the resulted additional components.

Summary of the Invention

The object of the present invention is to provide a battery pack which has a simple and compact design and can be easily manufactured with less components and more cost-efficiency compared to the prior fluid cooling systems.

According to an aspect of the present invention, the object is achieved by a cooling system used in a battery pack, wherein the battery pack comprises a housing for accommodating a plurality of battery cells and at least one separation wall for separating the battery cells from each other in an electrically insulating manner, characterized in that the cooling system comprises at least one heat dissipating means, which is partially embedded in the housing and/or the separation wall such that at least one portion of the heat dissipating means protrudes outwardly beyond the housing.

In accordance with a preferred embodiment of the invention, the heat dissipating means is made of metal； and/or the heat dissipating means and the separation wall are manufactured as a piece by injection molding.

In accordance with a preferred embodiment of the invention, the separation wall comprises a body having at least one thermal contact surface contacting with the corresponding battery cell and the heat dissipating means is partially embedded in the body without electrical contact with the battery cell.

In accordance with a preferred embodiment of the invention, the body consists of an upper and lower layers, between which the heat dissipating means is sandwiched； and/or the body is made of electrically insulating material； or the thermal contact surface of the body is formed by a layer of electrically insulating material； and/or the heat dissipating means protrudes from two opposite sides of the body.

In accordance with a preferred embodiment of the invention, the electrically insulating material is polymer.

In accordance with a preferred embodiment of the invention, the heat dissipating means is in a form of a rod, a wave, a plate, a sheet or grid, or any combinations thereof； and/or a portion of the heat dissipating means protruding outwardly beyond the housing is provided with at least one fin.

In accordance with a preferred embodiment of the invention, a plurality of heat dissipating means are embedded in the separation wall； and/or the cooling system further comprises a blower which is placed outside the housing for forcing the air to flow by a portion of the heat dissipating means protruding outwardly beyond the housing； and/or a portion of the separation wall protrudes outwardly beyond housing and supports a portion of the heat dissipating means protruding outwardly beyond the housing； and/or the heat dissipating means extends throughout the separation wall.

In accordance with a preferred embodiment of the invention, the heat dissipating means is centrally disposed in the body.

In accordance with a preferred embodiment of the invention, the plurality of heat dissipating means are mutually connected to each other by connecting features which conduct heat.

According to another aspect of the present invention, the objected is further achieved by a battery pack comprising the above cooling system.

According to the present invention, the battery pack can dissipate the heat generated in the cells in a simpler and more compact manner compared to the prior fluid cooling systems.

Brief Description of the Drawings

The invention and advantages thereof will be further understood by reading the following detailed description of some preferred exemplary embodiments with reference to the drawings in which:

Fig. 1 is a schematic diagram showing the structure of a battery pack according to an exemplary embodiment of the present invention；

Fig. 2 is a schematic partial view showing an exemplary embodiment of the cooling system with one heat dissipating means partially embedded in a separation wall；

Fig. 3 is a schematic partial view showing another exemplary embodiment of the cooling system with two heat dissipating means partially embedded in the separation wall.

Detailed Description of Preferred Embodiments

Fig. 1 illustrates a schematic diagram of a battery pack 1 according to an exemplary embodiment of the present invention. As shown in Fig. 1, the battery pack 1 generally comprises a housing 2, which defines an interior space 4 for accommodating a plurality of battery cells 5, and a cooling system having at least one heat dissipating means 10 for dissipating heat generated by the battery cells 5. The battery pack 1 further comprises at least one separation wall 3 which separates the battery cells 5 from each other in an electrically insulating manner. That means that the separation wall 3 and the battery cells 5 are alternately arranged in the housing 2. Thus, the electrical insulation of the battery cells 5 can be ensured by the provision of the separation wall 3.

Fig. 2 schematically illustrates an exemplary embodiment of the heat dissipating means 10 partially embedded in the separation wall 3 shown in Fig. 1. As shown in Fig. 2, the separation wall 3 comprises a body 7 having at least one thermal contact surface 9 contacting with the adjacent battery cells 5. Preferably, the heat dissipating means 10 is substantially centrally disposed in the body 7.

Preferably, the heat dissipating means 10 extends throughout the separation wall 3. Preferably, the heat dissipating means 10 protrudes from at least one peripheral edge of the body 7. More preferably, the heat dissipating means 10 protrudes from two opposite peripheral edges of the body 7.

Preferably, the body 7 can be made of electrically insulating material such as polymer and any other suitable materials. Additionally or alternatively, the thermal contact surface 9 of the body 7 can be formed by a layer of electrically insulating material to enable the body 7 to function electrically insulating separation between two adjacent battery cells 5.

The heat dissipating means 10 can be made of thermal conductivity material having high heat conductivity, such as metal and any other suitable materials. In the case of metal, the separation wall 3 and the heat dissipating means 10 can be manufactured for example by injection molding with metallic inserts. Further, the provision of the heat dissipating means 10 as a metal core can increase the mechanical strength of the separation wall 3 and thus of the battery pack 1.

As shown in Fig. 1, the heat dissipating means 10 extends in the separation wall 3 and then passes through the housing wall 12 such that it protrudes into the external environment. In other words, the heat dissipating means 10 extends or protrudes beyond the housing 2 with an end portion 13 thereof exposed to the external of the housing 2. The provision of the heat dissipating means 10 substantially improves the thermal conductivity of the separation wall 3 and enhances the heat transfer between the battery cells 5 and the separation wall 3. Further, the exposed end portion 13 allows the heat transferred from the battery cells 5 to the separation wall 3 to be dissipated to the ambient air.

It should be noted that the heat dissipating means 10 embedded in the body 7 means that the portion of the heat dissipating means 10 extending in the body 7 is positioned deeply in the body 7 and not exposed to the battery cells 5. Such an arrangement protects the heat dissipating means 10 from the battery cells 5 and other surroundings and also ensures the electrical insulation between the battery cells 5.

Preferably, the heat dissipating means 10 can take the form of a plate. However, the heat dissipating means 10 can also take any other suitable forms such as rod, wave, sheet or grid, or combination thereof, as long as the heat dissipating means can extend into the outside of the housing 2. Further, as shown in Fig. 1, for one separation wall 3, there can be provided more than one heat dissipating means of different or the same form (s) . Fig. 3 illustrates an exemplary separation wall 3 with two heat dissipating means 10. As shown in Fig. 3, the two heat dissipating means 10 can be concurrently extended parallel to the thermal contact surface 9 at respective different depths in the separation wall 3. It should be noted that the depth herein refers to the level in the depth direction of the separation wall as indicated by an arrow 8 shown in Figs. 2-3. In another exemplary embodiment, two or more rod-shaped heat dissipating means can be embedded in the body 7, which heat dissipating means can be extended parallel to each other at the same depth of the separation wall 3.

In the case of multiple heat dissipating means being provided in the separation wall 3, it’s preferred that these heat dissipating means can be mutually connected to each other by connecting features such that the heat can be uniformly distributed among the these heat dissipating means. This advantageously improves the temperature distribution over the whole separation wall 3.

Preferably, the heat dissipating means 10 each extends outwardly beyond the housing 1 with more than one end portions thereof. That means there are more than one end portions exposed to the external environment for one heat dissipating means 10 if viewed from the outside of the housing 2.

As an alternative embodiment, the body 7 can consist of an upper and lower layer between which the heat dissipating means is sandwiched. In this case, the upper and lower layer can for example be embodied as eclectically insulating coatings applied on the surface of the heat dissipating means.

It will be appreciated that the separation wall can exhibit any other suitable structures as long as the heat dissipating means can be embedded in the separation wall without electrical contact with the battery cells.

Preferably, the battery cells 5 are positioned side by side within the housing 2, as shown in Fig. 1. In particular, the battery cells each are arranged between two adjacent separation walls 3 in a thermal contact manner. In this case, with respect to the battery cells 3 located at the outermost, i.e., the cells 1#and n#shown in Fig. 1, a separation wall 3 is inserted between the cell 1#or n#and the housing walls. This ensures that each of the battery cells is sandwiched between two separation walls 3 to enable a sufficient thermal contact with the separation walls 3.

However, more preferably, such a heat dissipating means can be directly embedded in one or both of two lateral housing walls 14 of the housing 2. Further, the separation walls 3 and the housing 2 can be produced separately and then mechanically joined together. In this case, the respective slots can be provided in the housing wall of the housing 2 to allow the heat dissipating means to pass through the housing wall. In particular, a sealing means can be arranged between the slot and the separation wall to prevent the ambient air with humidity or dust from entering into the interior space 4 of the battery pack 1. Also, the separation walls 3 and the housing 2 can be formed as a single piece.

Preferably, the separation wall 3 can also protrude from an outer surface of the housing 2 and then the heat dissipating means 10 can extend beyond the separation wall 3. Such a configuration allows the heat dissipating means 10, in particular the end portion 13 thereof to be more stably supported by the separation wall 3.

Preferably, all of the housing walls can be embedded with the heat dissipating means. Also, the aforementioned arrangements of the heat dissipating means in the separation wall 3 can be applied to the heat dissipating means in the housing walls. In this case, the heat dissipation of the battery pack is further enhanced by the housing walls embedded with the heat dissipating means.

Preferably, a fan or blower can be placed outside the housing 2 to force the air to flow by the end portions 13 of the heat dissipating means 10.

Preferably, the end portion 13 of the heat dissipating means 10 exposed to the ambient air can be provided with fins such that the heat exchange with the ambient air can be further enhanced by increasing the outer surface area of the end portion 13.

During the operation of the battery pack 1, the battery cells 5 can generate heat which can then be transferred to the separation wall 3 and thus to the heat dissipating means 10 therein due to thermal contact between the battery cells 5 and the thermal contact surfaces 9. As the end portion 13 is exposed to the ambient air, the heat can then be conducted through the heat dissipating means 10 and dissipated to the external environment. As a consequence, it enables the battery cells 5 to be effectively cooled by the ambient air even though there is no air guided into the housing 2 and thus no direct contact between the battery cells 5 and the air.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. The attached claims and their equivalents are intended to cover all the modifications, substitutions and changes as would fall within the scope and spirit of the invention.

Claims

A cooling system used in a battery pack (1) , the battery pack (1) comprising a housing (2) for accommodating a plurality of battery cells (5) and at least one separation wall (3) for separating the battery cells (5) from each other in an electrically insulating manner, characterized in that the cooling system comprises at least one heat dissipating means (10) , which is partially embedded in the housing (2) and/or the separation wall (3) such that at least one portion of the heat dissipating means (10) protrudes outwardly beyond the housing (2) .
The cooling system according to claim 1, wherein

- the heat dissipating means (10) is made of metal； and/or

- the heat dissipating means (10) and the separation wall (3) are manufactured as a piece by injection molding.
The cooling system according to claim 1, wherein the separation wall (3) comprises a body (7) having at least one thermal contact surface contacting with the corresponding battery cell (5) and the heat dissipating means (10) is partially embedded in the body (7) without electrical contact with the battery cell (5) .
The cooling system according to claim 3, wherein

- the body (7) consists of an upper and lower layers, between which the heat dissipating means (10) is sandwiched； and/or

- the body (7) is made of electrically insulating material； or the thermal contact surface of the body (7) is formed by a layer of electrically insulating material； and/or

- the heat dissipating means (10) protrudes from two opposite sides of the body (7) .
The cooling system according to claim 4, wherein the electrically insulating material is polymer.
The cooling system according to any one of claims 1-5, wherein

- the heat dissipating means (10) takes a form of a rod, a wave, a plate, a sheet or grid, or any combinations thereof； and/or

- a portion of the heat dissipating means (10) protruding outwardly beyond the housing (2) is provided with at least one fin.
The cooling system according to any one of claims 1-5, wherein

- a plurality of heat dissipating means (10) are embedded in the separation wall (3) ； and/or

- the cooling system further comprises a blower which is placed outside the housing (2) for forcing the air to flow by a portion of the heat dissipating means (10) protruding outwardly beyond the housing (2) ； and/or

- a portion of the separation wall (3) protrudes outwardly beyond housing (2) and supports a portion of the heat dissipating means (10) protruding outwardly beyond the housing (2) ； and/or

- the heat dissipating means (10) extends throughout the separation wall (3) .
The cooling system according to any one of claims 3-5, wherein

the heat dissipating means (10) is centrally disposed in the body (7) .
The cooling system according to claim 7, wherein

the plurality of heat dissipating means (10) are mutually connected to each other by connecting features which conduct heat.
A battery pack (1) , characterized in that the battery pack (1) comprises a cooling system according to any one of claims 1-9.