GB2543863A

GB2543863A - Battery pack

Info

Publication number: GB2543863A
Application number: GB1522758.0A
Authority: GB
Inventors: Woodall Christopher
Original assignee: Tata Motors European Technical Centre PLC; Tata Motors Ltd
Current assignee: Tata Motors European Technical Centre PLC; Tata Motors Ltd
Priority date: 2015-10-30
Filing date: 2015-12-23
Publication date: 2017-05-03
Anticipated expiration: 2035-12-23
Also published as: GB201522758D0; GB2543863B

Abstract

A battery pack 1 for a vehicle comprises: a housing 7; a plurality of battery modules 4, each having at least one cell; and at least one cooling plate 8 for cooling the battery modules. The cooling plate(s) is arranged to form a plurality of compartments 6 within the housing. At least one of the battery modules is disposed in each of the compartments. Each cooling plate may be actively cooled via a liquid coolant which enters the plate via a coolant inlet port, circulates within the cooling plates and exits via a coolant outlet port. Each compartment may be connected via a vent inlet 17 to at least one vent conduit formed in the cooling plate for venting gas to an ambient environment via a vent outlet 18. Each cooling plate may extend upwardly above the battery modules to form a void 14 in each compartment, wherein the vent inlet opens into the void. Each vent conduit may have a sealing means (e.g. vent disc, burst valve or frangible membrane) for inhibiting the ingress of water or moisture. The sealing means may be configured to open in dependence on a thermal event in the battery module in the compartment associated with the vent conduit.

Description

BATTERY PACK TECHNICAL FIELD

The present disclosure relates to battery pack. More particularly, but not exclusively, the present disclosure relates to a battery pack for a vehicle. The battery pack may be a traction battery for supplying electrical energy to a traction machine.

BACKGROUND

It is known to provide a vehicle with a battery pack comprising a plurality of battery modules. Cooling plates are disposed adjacent to the battery modules to provide active cooling. In the event of a thermal event, an affected battery module emits gases and thermal energy. The battery pack may have one or more grommet which is blown out if the internal pressure increases, thereby preventing the build-up of internal pressure. The vented gases are free to disperse within the battery pack. In certain scenarios, this may allow the thermal event to propagate to other battery modules.

It is against this backdrop that the present invention has been conceived. At least in certain embodiments, the present invention seeks to overcome or ameliorate at least some of the shortcomings associated with the prior art battery packs.

SUMMARY OF THE INVENTION

Aspects of the present invention relate to a battery pack; and a vehicle comprising a battery pack. The battery pack may be a traction battery for supplying electrical energy to a traction machine.

According to a further aspect of the present invention there is provided a battery pack for a vehicle, the battery pack comprising: a housing; a plurality of battery modules each having at least one cell; and at least one cooling plate for cooling the battery modules; wherein said at least one cooling plate is arranged to form a plurality of compartments within said housing; at least one of said battery modules being disposed in each of said compartments. The battery modules may be disposed in separate compartments within the housing. The battery modules may be isolated from each other. At least in certain embodiments, the compartments may be sealed. At least in certain embodiments a thermal event in a battery module is managed within the battery pack. The migration/propagation of the thermal event between battery modules is inhibited. The battery pack may prevent thermal runaway within the battery pack. The cooling plates function as a baffle between battery modules. The baffles help contain gasses and thermal energy within compartments.

The at least one cooling plate may cooperate with at least one sidewall and/or a base of the housing to form said compartments. A sealed connection may be formed between the at least one cooling plate and said at least one sidewall of the housing and/or the base of the housing. The at least one cooling plate may extend between opposing first and second sidewalls of the housing. The housing may comprise a closure panel for closing said compartments. The closure panel may be in the form of a cover for the battery pack.

The battery modules may be arranged in one or more layer. The closure panel may be an intermediate panel disposed between rows and/or columns of battery modules. The battery modules may, for example, be arranged in a vertical and/or horizontal array. The closure panel may extend horizontally or vertically.

The compartments may be sealed to reduce the risk of thermal propagation within the pack. Each cooling plate may be sealingly connected to the housing and/or to the closure panel. The closure panel may be fastened to said cooling plates, for example by one or more mechanical fastener. Alternatively, or in addition, the closure panel may be bonded or welded to the cooling plates.

The battery pack may comprise a plurality of said cooling plates arranged to form a plurality of said compartments in the housing.

The or each cooling plate may be sealingly connected to the housing and / or to the closure panel.

The cooling plates may be actively cooled. In particular, a liquid coolant may be circulated within the cooling plates. Active cooling may extend the time period for which the cooling plates are able to withstand exposure to a thermal event without failing.

Each compartment may be connected to one or more vent conduit for venting gas to an ambient environment. The vent conduit may form an exhaust path. By controlling the venting of gasses, the one or more vent conduit protects other components within the battery pack. The vent conduits may be maintained separate from each other. Each vent conduit may have one or more vent inlet which opens into one of said compartments. Each vent conduit may have one or more vent outlet which opens to said ambient environment. In the event of a thermal event, the one or more vent conduit duct hot gases from the compartment containing the affected battery module to the one or more vent outlet. The one or more vent outlet may be disposed at appropriate locations on the housing. A manifold may also be provided for collecting the gases vented from the compartment. The ambient environment may, for example, be atmosphere. The migration or propagation of the thermal event within the battery pack is inhibited by containing and directing the vented gasses to the one or more vent outlet.

The vent inlet and/or the vent conduit and/or the vent outlet may be formed in the cooling plate. The vent conduit may be integrated into the cooling plate. The vent conduit may be cooled by the coolant circulated within the cooling plate, thereby cooling gases vented through the vent conduit. The gases may be vented through the one or more vent outlet at a reduced temperature. The inlet vent may be disposed on only one side of the cooling plate so as to maintain the baffle between compartments. At least in certain embodiments, the compartments may be vented internally within the battery pack without adding additional parts. The cost of modifying the cooling plates to incorporate the vent conduit would be nominal as they are already required for cooling and the addition of one more channel could be performed with relative ease.

The cooling plates may extend upwardly above the battery modules to form a void in each compartment. The one or more vent inlet may open into said void.

Each vent conduit may comprise sealing means for inhibiting the ingress of water or moisture. The sealing means may comprise a one-way valve, for example. The sealing means may be configured to open in dependence on a thermal event in the battery module in the compartment associated with said vent conduit. The sealing means may comprise one or more of the following: a vent disc, a burst valve or a frangible membrane.

The battery pack may be a traction battery for supplying electrical energy to a traction machine.

According to a further aspect of the present invention there is provided a vehicle comprising a battery pack as claimed in any one of the preceding claims.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments of the present invention will now be described, by way of example only, with reference to the accompanying figures, in which:

Figure 1 shows a schematic representation of a vehicle incorporating a traction battery in accordance with an embodiment of the present invention;

Figure 2 shows a perspective view of one of the battery modules making up the traction battery shown in Figure 1;

Figure 3 shows a schematic representation of the traction battery shown in Figure 1;

Figure 4 shows a schematic representation of a cooling plate of the traction battery shown in Figure 2.

DETAILED DESCRIPTION A battery pack 1 in accordance with an embodiment of the present invention will now be described with reference to the accompanying Figures. As shown schematically in Figure 1, the battery pack 1 is disposed in a vehicle 2, such as an automobile or a sports utility vehicle.

The battery pack 1 in the present embodiment is a traction battery configured to supply electrical energy to one or more traction machine 3 to propel the vehicle 2. As shown in Figure 1, the battery pack 1 comprises a plurality of battery modules 4 arranged in an array. As shown in Figure 2, the battery modules 4 each comprise a plurality of cells 5 which are electrically connected to each other. As shown in Figure 3, the battery modules 4 are housed in compartments 6 formed in a housing 7. A plurality of cooling plates 8 are disposed within the housing 7 to provide active cooling of the battery modules 4. The cooling plates 8 in the present embodiment are arranged to form the compartments 6 for the battery modules 4.

As shown in Figure 3, the housing 7 comprises sidewalls 9, a base 10 and a closure panel 11 (represented by dashed lines). In the present embodiment the closure panel 11 is in the form of a cover for the housing 7. In alternate arrangements, the closure panel 11 may be an intermediate panel disposed between rows and/or columns of battery modules 4 arranged in a vertical and/or horizontal array. The cooling plates 8 are arranged vertically within the housing 7 and extend substantially parallel to each other. Each cooling plate 8 extends between opposing sidewalls 9 such that the housing 7 is sub-divided into a plurality of said compartments 6. The cooling plates 8 cooperate with the sidewalls 9, the base 10 and the closure panel 11 to close the compartments 6 formed in the housing 7. As described herein, the compartments 6 are isolated from each other to separate the battery modules 4 from each other. At least in certain embodiments, each compartment 6 can be at least substantially sealed. The cooling plates 8 form a boundary between adjacent compartments 6 and are disposed between adjacent battery modules 4 within the battery pack 1.

The cooling plates 8 typically have a sandwich construction comprising thermally-conductive outer plates mounted to opposing faces of an intermediate plate. As shown schematically in Figure 4, the cooling plates 8 each have a coolant inlet port 12 and a coolant outlet port 13. A liquid coolant is pumped through the cooling plates 8 to transfer heat from the battery pack 1. The coolant is circulated through a coolant line (not shown) formed within the cooling plate 8. The coolant line in the present embodiment is defined by a channel formed in the intermediate plate of the cooling plate 8. The coolant line follows a path within the cooling plate 8 to promote heat transfer. The coolant exits the coolant outlet port 13 and is passed through a heat exchanger (not shown) and then re-circulated through the cooling plates 8. It will be understood that the cooling plates 8 may be arranged in one or more cooling circuit. The cooling plates 8 and the sidewalls 9 extend vertically upwardly above the battery modules 4 to form a space or void 14 above the battery module 4 in each compartment 6.

The cooling plates 8 form a sealed connection with the sidewalls 9 and the base 10 of the housing 7. The cooling plates 8 may, for example, locate in a slot or channel formed in the sidewalls 9 and the base 10 of the housing 7. An adhesive or sealant may be used to seal the connection between the cooling plates 8 and the housing 7. The closure panel 11 is fixedly mounted to the top of the housing 7. One or more mechanical fastener (not shown) is provided to fasten the closure panel 11. The closure panel 11 cooperates with the top of the cooling plates 8 and the sidewalls 9 to close the compartments 6. A sealant or adhesive may be provided between the closure panel 11 and the cooling plates 8 and the sidewalls 9. The closure panel 11 seals the compartments 6, thereby isolating the battery modules 4 from each other.

The cooling plates 8 each comprise a vent conduit 16 for venting gas from one of the compartments 6. The vent conduit 16 in the present embodiment is defined by a channel formed in the intermediate plate of the cooling plate 8. The vent conduit 16 has a vent inlet 17 and a vent outlet 18. The vent inlet 17 opens into the compartment 6. In particular, the vent inlet 17 opens into the void 14 formed above the battery modules 4. The vent outlet 18 is open to an ambient environment, such as atmosphere. It will be appreciated that each cooling plate 8 has at least one of said vent conduits 16. However, the vent conduits 16 are not connected to each other, thereby helping to ensure that the compartments 6 (and therefore the battery modules 4) remain isolated from each other. Thus, in the event of a thermal event, gases from one compartment 6 are vented to the ambient environment, rather than into another compartment 6. The vent path for gases emitted from the battery modules 4 is illustrated by an arrow 15 in Figure 4. The cooling plates 8 function as baffles to reduce propagation of a thermal event. The vent outlet 18 formed in the cooling plate 8 could optionally be connected to a separate conduit to duct gases to a remote outlet. A sealing means may be provided to seal the vent conduit 16 to inhibit the ingress of water or moisture. The sealing means may be in the form of a one-way valve disposed at or proximal to said vent outlet 18. The one-way valve may comprise a vent disc which is configured to seal the vent conduit 16 during normal operation of the battery pack 1. However, the vent disc may selectively open to allow gases from the compartment 6 to vent through the vent conduit 16 to atmosphere. The vent disc may be configured to open in dependence on an increased pressure in the compartment 6, for example caused by a thermal event in the battery module(s) 4 disposed in that compartment 6. The vent disc may, for example, comprise a circular spring steel disc mounted in an annular support frame (not shown). An increase in pressure in the compartment 6 causes the vent disc to be displaced from the annular support frame, thereby opening the vent conduit 16. It will be appreciated the sealing means may be in other forms, for example a frangible membrane or a burst valve. Rather than opening in response to a pressure change, the sealing means could be ruptured due to a temperature increase associated with a thermal event in the battery module 4.

In the assembled battery pack 1, each battery module 4 is disposed in one of said compartments 6. The compartments 6 are isolated from each other to protect the battery modules 4. Cooling plates 8 are disposed between adjacent battery modules 4 and, in use, liquid coolant is circulated through the cooling plates 8 to perform cooling. The cooling plates 8 have vent conduits 16 formed therein to provide separate vent paths for each compartment 6. A sealing means is optionally provided for sealing the vent conduits 16. In the event of a thermal event in one of said battery modules 4, the sealing means open the vent conduits 16 to allow gases to vent from the compartment 6 through the vent conduits 16. The gases are vented directly to the ambient surroundings, rather than via another compartment 6. Thus, the battery modules 4 are separated from each other, helping to reduce the possibility of propagation of the thermal event to another battery module 4.

It will be appreciated that various changes and modifications can be made to the invention described herein without departing from the scope of the present invention.

For example, the vent conduit 16 formed in the cooling plates 8 may each be connected to an outlet conduit (not shown). The sealing means may be disposed in said outlet conduit. The vent conduits 16 and/or the outlet conduits may be connected to a manifold. The manifold may comprise multiple inlets which are connected to a single manifold outlet. The sealing means may be associated with said manifold outlet.

Claims

CLAIMS:

1. A battery pack (1) for a vehicle (2), the battery pack (1) comprising: a housing (7); a plurality of battery modules (4) each having at least one cell (5); and at least one cooling plate (8) for cooling the battery modules (4); wherein said at least one cooling plate (8) is arranged to form a plurality of compartments (6) within said housing (7); at least one of said battery modules (4) being disposed in each of said compartments (6).

2. A battery pack (1) as claimed in claim 1, wherein the at least one cooling plate (8) cooperates with at least one sidewall and/or a base of the housing (7) to form said compartments (6).

3. A battery pack (1) as claimed in claim 2, wherein said at least one cooling plate (8) extends between opposing first and second sidewalls of the housing (7).

4. A battery pack (1) as claimed in any one of claims 1, 2 or 3, wherein the housing (7) comprises a closure panel for closing said compartments (6).

5. A battery pack (1) as claimed in any one of claims 1 to 4 comprising a plurality of said cooling plates (8) arranged to form a plurality of said compartments (6) in the housing (7).

6. A battery pack (1) as claimed in any one of the preceding claims, wherein the or each cooling plate (8) is sealingly connected to the housing (7) and/or to the closure panel (11)-

7. A battery pack (1) as claimed in any one of the preceding claims, wherein each compartment (6) is connected to one or more vent conduit (16) for venting gas to an ambient environment, wherein each vent conduit (16) has one or more vent inlet which opens into one of said compartments (6).

8. A battery pack (1) as claimed in claim 7, wherein each vent conduit (16) has one or more vent outlet which opens to said ambient environment.

9. A battery pack (1) as claimed in claim 7 or claim 8, wherein said one or more vent conduit (16) is formed in the cooling plate (8).

10. A battery pack (1) as claimed in claim 9, wherein the or each cooling plate (8) extends upwardly above the battery modules (4) to form a void (14) in each compartment (6), said one or more vent inlet opening into said void (14).

11. A battery pack (1) as claimed in any one of claims 7 to 10, wherein each vent conduit (16) comprises sealing means for inhibiting the ingress of water or moisture.

12. A battery pack (1) as claimed in claim 11, wherein said sealing means is configured to open in dependence on a thermal event in the battery module (4) in the compartment (6) associated with said vent conduit (16).

13. A battery pack (1) as claimed in claim 11 or claim 12, wherein said sealing means comprises one or more of the following: a vent disc, a burst valve or a frangible membrane.

14. A battery pack (1) as claimed in any one of the preceding claims, wherein said battery pack (1) is a traction battery for supplying electrical energy to a traction machine (3).

15. A vehicle (2) comprising a battery pack (1) as claimed in any one of the preceding claims.

16. A battery pack (1) substantially as herein described with reference to the accompanying figures.

17. A vehicle substantially as herein described with reference to the accompanying figures.