WO2022256728A1

WO2022256728A1 - Battery pack thermal chimney

Info

Publication number: WO2022256728A1
Application number: PCT/US2022/032284
Authority: WO
Inventors: Logan FIMBRES; Wesley Thibault; Willans LEE; Craig EASTON; Kameron Buckhout
Original assignee: Romeo Systems Technology, Llc
Priority date: 2021-06-05
Filing date: 2022-06-04
Publication date: 2022-12-08

Abstract

An energy storage system is disclosed comprising: an outer housing; a plurality of battery modules disposed within said outer housing, wherein each said battery module comprises: a battery module housing; a plurality of battery cells disposed within said battery module housing; and a module outlet from said battery module housing, wherein said module outlet comprises a closed configuration and an open configuration. The energy storage system further comprises: an exhaust compartment contained within said outer housing, wherein an interior of each said battery module housing is separately connectable with said exhaust compartment when its corresponding said module outlet is in said open configuration; and an exhaust flow-path extending from said exhaust compartment to an exterior of said outer housing.

Description

TITLE: BATTERY PACK THERMAL CHIMNEY

FIELD

[0001] The present disclosure generally relates to battery packs and, more particularly, a battery pack configuration that address a thermal runaway condition or other over pressurizing event within a battery pack.

BACKGROUND

[0002] Various attempts have been made to address thermal runaway in battery packs.

Most involve venting individual battery modules in a pack directly to the environment. These solutions may not be completely suitable to current and future needs for addressing a thermal runaway event. It is desirable for new systems and devices to address such needs.

SUMMARY

[0003] In an example embodiment, an energy storage system is disclosed comprising: an outer housing; a plurality of battery modules disposed within said outer housing, wherein each said battery module comprises: a battery module housing; a plurality of battery cells disposed within said battery module housing; and a module outlet from said battery module housing, wherein said module outlet comprises a closed configuration and an open configuration. The energy storage system further comprises: an exhaust compartment contained within said outer housing, wherein an interior of each said battery module housing is separately connectable with said exhaust compartment when its corresponding said module outlet is in said open configuration; and an exhaust flow-path extending from said exhaust compartment to an exterior of said outer housing.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] In accordance with various exemplary embodiments:

[0005] Figure 1A is a schematic of an energy storage system that utilizes a pair of internal exhaust chimneys for multiple battery modules.

[0006] Figure IB is a perspective schematic view of a battery module housing for one of the battery modules from the energy storage system of Figure 1A.

[0007] Figure 1 C is a schematic of a representative battery cell that may be used by the energy storage system of Figure 1A. [0008] Figure 2A is a perspective view of an energy storage system that utilizes an internal exhaust chimney for multiple battery modules.

[0009] Figure 2B is another perspective view of the energy storage system of Figure

2A. [0010] Figure 2C is a perspective view of a chimney plate and shield for the exhaust chimney of the energy storage system of Figure 2A.

[0011] Figure 2D is a perspective view of the energy storage system of Figure 2A, with the chimney plate and shield from Figure 2C having been removed and that illustrates a pair of exhaust valves for the exhaust chimney. [0012] Figure 2E is a perspective view in accordance with Figure 2D, but with the exhaust valves having been removed and that illustrates a pair of module outlets for each battery module of the energy storage system of Figure 2A.

[0013] Figure 2F is a perspective view of an interior of a sidewall for each battery module that incorporates a pair of module outlets for the energy storage system of Figure 2A. [0014] Figure 2G and 2H are each cutaway, perspective views of the energy storage system of Figure 2A, illustrating the exhaust chimney on one side of a battery pack housing for the energy storage system.

[0015] Figure 21 is a perspective view of a plurality of battery cells that may be utilized by each battery module of the energy storage system of Figure 2A. [0016] Figure 2J is a perspective view illustrating an underside of a pair of thermal barriers, each such thermal barrier being disposed between a pair of adjacent battery modules within a stack for the energy storage system of Figure 2A.

[0017] Figure 2K another perspective view of the thermal barriers from Figure 2J, but illustrating an upper side of such thermal barriers. [0018] Figure 2L is another perspective view illustrating the underside of a pair of thermal barriers shown in Figures 2J.

[0019] Figure 3A is a perspective view of an energy storage system in the form of a tower and that utilizes a pair of internal exhaust chimneys for multiple battery modules, each battery module being arranged for accessing each internal exhaust chimney. [0020] Figure 3B is a perspective, partially transparent view of the energy storage system of Figure 3 A.

[0021] Figure 3C is a perspective view of the energy storage system of Figure 3A, with a chimney plate having been removed to illustrate the corresponding internal chimney. [0022] Figure 3D is a perspective view of a stack of thermal barriers and battery module vents used by the energy storage system of Figure 3 A to access the pair of internal chimney. [0023] Figure 3E is an enlarged, perspective view of a portion of the stack shown in

Figure 3D. [0024] Figure 3F is a perspective view of an interior side of one of the module vents for a battery module used by the energy storage system of Figure 3 A.

[0025] Figure 3G is a perspective view of an exterior side of module vent of Figure 3E.

[0026] Figure 3H is an enlarged, perspective view of a portion of one of the internal chimneys for the energy storage system of Figure 3 A, and illustrating a corresponding exhaust header at/toward the top of the tower.

[0027] Figure 31 is a plan view of a variation of the energy storage system of Figure

3 A that utilizes valves two fluidly interconnect battery modules with an internal chimney. [0028] Figures 3J and 3K are plan views of example chimney embodiments showing various aspects. [0029] Figure 3L is an exploded perspective view of an example chimney embodiment showing various aspects.

DETAILED DESCRIPTION

[0030] For the sake of brevity, conventional techniques for battery pack construction, configuration, operation, measurement, optimization, control, and/or use, as well as conventional techniques for thermal management, fire control, battery packaging, vehicle safety, and/or the like, may not be described in detail herein. Furthermore, the connecting lines shown in various figures contained herein are intended to represent exemplary functional relationships, electrical connections/relationships, and/or physical couplings between various elements. It should be noted that many alternative or additional functional relationships, components, or physical connections may be present in a practical system or related methods of use, for example a battery pack for an electric vehicle.

[0031] Various shortcomings of prior battery packs can be addressed by utilizing battery packs, insulating components, venting components, valves, and/or related components configured in accordance with principles of the present disclosure. For example, prior approaches typically involved a single vent per module. Such one-to-one vent/module solutions typically involve a single one-way valve per module, directly venting an individual module to the atmosphere. These solutions have the drawback that the vented products (gases, particles, flames) may reach the surrounding environment with the flames still unextinguished. These approaches fail to satisfy some current and likely future standards requiring set amounts of time before products of combustion exit the pack.

[0032] In contrast, exemplary systems and methods disclosed herein enable improved safety, for example when using a battery pack by using a thermal chimney concept. The thermal chimney allows for increased time before products of combustion reach the environment outside the pack. The thermal chimney provides a two stage solution where the first stage is the vent from the module to the chimney and the second stage is the chimney to the outside of the pack. In an example embodiment, this provides a longer tortuous path to exhaust flames prior to the products of combustion exiting the pack. In an example embodiment, this will make it easier for packs to meet standards for the time from a thermal event to products being exhausted. Moreover, such a solution may help with isolation of battery modules to reduce fire propagation. Module to module isolation of thermal events is a great advantage. Such solutions may also facilitate delayed flame progress to exterior of pack and/or increased time for occupants to exit a damaged or disabled vehicle, etc. In an example embodiment, the solution may help provide directional control of the thermal event. For example, the thermal event could be directed downwards, away from the assumed location of the vehicle cabin. Moreover, the thermal event could be directed in any desirable direction. [0033] Accordingly, a battery pack configured in accordance with principles of the present disclosure may be configured with any suitable components, structures, and/or elements in order to provide desired dimensional, mechanical, electrical, chemical, and/or thermal properties. For example, a battery pack: may have a single thermal chimney or multiple thermal chimneys; may comprise a group of battery modules in any suitable number, arrangement, or configuration, for example a 1 x 3, 1 x 10, 1 x 20, etc. single column stack, a 2 x 3, 2 x 10, 2 x 20, etc. double column stack, a configuration having 4 packs per layer in a 2 x 2 arrangement and any suitable number of layers, such as 5 layers (20 total modules), 10 layers (40 total modules), or the like. In an example embodiment, the battery pack may utilize identical battery modules, or battery modules that differ one from another. In an example embodiment, the battery pack may utilize passive smoke or fire routing components (e.g., thermal insulation layers, sealants, flow paths, barriers, funnels, vents, headers, and the like) and/or active components (e.g., valves, isolation components that deform or expand responsive to applied heat in order to block or obstruct a previously available path for smoke to flow, and the like). In an example embodiment, the battery pack may be configured to provide at least a threshold amount of time between thermal runaway occurring in a battery cell in the battery pack, and flame escaping the battery pack. [0034] In accordance with various exemplary embodiments, an energy storage system or battery pack is illustrated in Figure 1 A and is identified by reference numeral 10. The energy storage system 10 includes an outer or battery pack housing 12, along with a plurality of batery modules 30 that are disposed within (e.g., enclosed by) the batery pack housing 12 and furthermore that are arranged in a vertically-extending stack. Any appropriate number of batery modules 30 may be utilized by the batery pack 10 (three being shown in Figure 1A). Each batery module 30 includes a batery module housing 32, along with a plurality of batery cells 80 that are disposed within (e.g., enclosed by) the corresponding batery module housing 32. An interior 44 of each batery module 30 may be characterized as being at fluidly isolated from each internal chimney 60 (as well as possibly an interior 24 of the batery pack housing 12) under normal operating conditions.

[0035] The batery pack housing 12 includes an upper or top wall 14 and a lower or botom wall 16 that are disposed in vertically spaced relation to one another. A first sidewall 20 and a second sidewall 22 each extend between the upper wall 14 and lower wall 16. A pair of end walls (not shown) of the batery pack housing 12 extend between both the upper wall 14 and the lower wall 16, as well as between the first sidewall 20 and the second sidewall 22 to define an enclosed interior 24 for the batery pack housing 12. The spacing between these end walls may be characterized as corresponding with a length dimension of the batery pack housing 12, the spacing between the first sidewall 20 and the second sidewall 22 may be characterized as corresponding with a width dimension of the batery pack housing 12, and the spacing between the upper wall 14 and the lower wall 16 may be characterized as corresponding with a height dimension of the batery pack housing 12.

[0036] The batery module housing 32 of each batery module 30 will typically be of a common configuration. Referring now to both Figures 1 A and IB, the batery module housing 32 includes an upper or top wall 34 and a lower or botom wall 36 that are disposed in vertically spaced relation to one another. A first sidewall 40 and a second sidewall 42 each extend between the upper wall 34 and lower wall 36. A pair of end walls 38 of the batery module housing 32 each extend between both the upper wall 34 and the lower wall 36, as well as between the first sidewall 40 and the second sidewall 42 to define an enclosed interior 44 for the batery module housing. The spacing between the end walls 38 may be characterized as corresponding with a length dimension of the batery module housing 32, the spacing between the first sidewall 40 and the second sidewall 42 may be characterized as corresponding with a width dimension of the battery module housing 32, and the spacing between the upper wall 34 and the lower wall 36 may be characterized as corresponding with a height dimension of the battery module housing 32. The end walls of the battery pack housing 12 would face and be disposed beyond the corresponding end wall of each of the battery modules 30.

[0037] The battery modules 30 are disposed in a stack that extends in the vertical dimension (corresponding with the spacing between the upper wall 14 and the lower wall 16 of the battery pack housing 12). Stated another way, the various battery modules 30 are disposed in vertically spaced (and/or overlying) relation to one another within the stack. In any case, each adjacent pair of battery modules 30 of the battery pack 10 may be separated by an open space 56 within the stack (e.g., a minimum gap of 10 mm for at least certain configurations/applications).

[0038] The first sidewall 40 of each battery module 30 faces or projects toward, and is spaced from the first sidewall 20 of the battery pack housing 12. Similarly, the second sidewall 42 of each battery module 30 faces or projects toward, and is spaced from the second sidewall 22 of the battery pack housing 12. A partition 26 may be disposed between the first sidewall 20 of the battery pack housing 12 and the first sidewall 40 of each battery module 30, although such may not be required in one or more instances and/or for one or more applications. Any such partition 26 would include a plurality of vents 28 (any appropriate number of vents 28 may be utilized and may be disposed in any appropriate arrangement; the vents 28 only being schematically shown in Figure 1A). Similarly, another such partition 26 may be disposed between the second sidewall 22 of the battery pack housing 12 and the second sidewall 42 of each battery module 30 (again, although such may not be required in one or more instances and/or for one or more applications). In any case, what may be characterized as an internal exhaust compartment or chimney 60 is located in the spacing between the first sidewall 20 of the battery pack housing 12 and the first sidewall 40 of each of the battery modules 30 within the stack - the chimney 60 thereby being vertically extending as well. Another internal exhaust compartment or chimney 60 is located in the spacing between the second sidewall 22 of the battery pack housing 12 and the second sidewall 42 of each of the battery modules 30 within the stack. A single exhaust compartment 60 may be appropriate for one or more applications/circumstances (e.g., Figures 2A-2L), while the illustrated multiple and opposingly disposed exhaust compartments 60 may be appropriate for other applications/circumstances (e.g., Figures 3A-3I). Each chimney 60 could extend along the entire length of each side of the battery pack 10, or could extend along only a portion of length of each side of the battery pack 10. Moreover, each chimney 60 may be linear, curvilinear, zig-zag, and/or may comprise various internal baffles, funnels, bends, switchbacks, or other similar components or configurations in order to lengthen a flow path for hot gas or flame between a battery module 30 and the exterior of battery pack 10.

[0039] Each exhaust compartment 60 is available to address a thermal event in one or more of the battery modules 30 (or any over-pressurization that may occur within a battery module 30), for instance a battery module 30 that is undergoing a thermal runaway. A battery module 30 that is in thermal runaway may result in a rapid increase of both the temperature and pressure within the corresponding battery module housing 32. Combustion could also occur within a battery module 30 that is undergoing thermal runaway, and which may generate combustion byproducts including smoke and/or flames. In this regard, the first sidewall 40 of each battery module 30 includes what may be characterized as one or more module outlets 46, with each module outlet 46 being in a closed configuration under normal conditions (at which time the interior 44 of a given battery module 30 may be at least substantially fluidly isolated from the corresponding internal exhaust compartment 60). However, each module outlet 46 of each battery module 30 is also disposable in an open configuration in response to a certain pressure/pressure increase within the interior 44 of a given battery module 30 (at which time the interior 44 of a given battery module would then be in fluid communication with the exhaust compartment 60 via the open configuration of the corresponding module outlet(s)). Such a module outlet 46 may be of any appropriate configuration, for instance in the form of a rupturable member (e.g., a cover (including a scored/perforated cover, seal, burst tape, burst paper, or the like)), a valve that changes from a closed configuration to an open configuration in response to reaching a threshold pressure within the corresponding battery module 30 (e.g., a pressure relief valve), or the like. The second sidewall 42 of each battery module 30 similarly includes one or more of the noted module outlets 46 when the second internal exhaust compartment or chimney 60 is being utilized.

[0040] Hot gases, combustion byproducts, smoke, flames, or the like may be introduced into one or both of the internal exhaust compartments or chimneys 60 during a thermal runaway scenario/condition (through one or more module outlets 46 from one or more battery modules 30 when in their respective open configuration). In this regard, each exhaust compartment 60 being utilized by the battery pack 10 further includes one or more exhaust compartment or chimney outlets 62. Multiple exhaust compartment outlets 62 may be disposed in any appropriate arrangement. Each exhaust compartment outlet 62 may be disposed at any appropriate position along the height dimension of the corresponding exhaust compartment 60 (the height dimension again coinciding with the spacing between the upper wall 14 and the lower wall 16 of the battery pack housing 12), each exhaust compartment outlet 62 may be of any appropriate configuration, or both. Representative configurations for a given exhaust compartment outlet 62 include a continually open exhaust flowpath (e.g., a port, orifice, or aperture of a fixed size; one or more flow channels) such that the corresponding exhaust compartment 60 is in continual fluid communication with the external environment of the battery pack 10 (e.g., atmosphere), a valve (e.g., a valve that opens to accommodate a flow out of the corresponding exhaust compartment 60 in response to the pressure within the exhaust compartment 60 reaching a certain threshold (e.g., a pressure relief valve); a throttle valve), or the like.

[0041] In an example embodiment, having at least one internal chimney 60 into which each battery module 30 may separately direct a flow (e.g., gas, smoke, flames, particulate) into an internal chimney 60 segregates the battery modules 30 from one another and also mitigates the propagation of hot gases and flames throughout the interior of the battery pack 10.

[0042] Additional features may be utilized by the battery pack 10 to address a thermal runaway condition of one or more of its battery modules 30. For example, at least one thermal barrier or thermal insulator 50 may be disposed between each adjacent pair of battery modules 30 within the stack. For instance, a mica sheet may be secured to the exterior surface of the lower wall 36 of each battery module 30 in the stack that faces or projects toward an upper wall 34 of an adjacent battery module 30 in the stack. The thermal barrier 50 could be a formed part of a given battery module 30, and may be shaped/contoured to direct flow towards a corresponding internal chimney 60, for example via a funnel structure or the like. Moreover, one or more segments 52 of an intumescent material (for example, butyl or epoxy “Fi-Block” offered by Sekisui Chemical) may be appropriately secured relative to a corresponding battery module 30 in the stack so as interface with the open space 56 between an adjacent pair of battery modules 30 in the stack. Such a segment(s) 52 may expand to fill all or a portion of the open space 56 between an adjacent pair of battery modules 30 in the stack upon exposure to at least a certain temperature, which should further thermal isolate adjacent pairs of battery modules 30 in the stack 70 from one another (e.g., particularly for the case where only one of the two adjacent modules is undergoing a thermal event, such as a thermal runaway) and that may further facilitate directing a flow into one or more of the internal chimneys 60. Rubber isolators (e.g., high temperature silicone) may be disposed at various locations between the battery module housing 32 of each battery module 30 and the battery pack housing 12, for example in order to more effectively isolate the battery modules 30 from one another and/or provide sealed or leak-resistant paths for smoke or flame within battery pack 10. [0043] The batery cells 80 of each batery module 30 may be of any appropriate type, and each batery module 30 may utilize any appropriate number of batery cells 80 that are disposed in any appropriate arrangement. The various batery cells 80 may incorporate a positive terminal and a negative terminal on a common end 82 of a given batery cell 80. In any case, the various batery cells 80 may be interconnected in series and/or in parallel to provide energy storage and/or electric power to a load/system as an integrated unit, including for an electric vehicle application in which case the batery pack 10 may utilize a relatively large number of individual lithium ion batery cells 80.

[0044] A functional schematic of a lithium ion battery cell is illustrated in Figure 1C and is identified by reference numeral 90. The batery cell 90 includes a positive electrode 92a, a negative electrode 92b, and a pair of current collectors 94. A membrane (e.g., separator) 96 may be disposed between the electrodes 92a, 92b, with electrolyte being contained between the separator 96 and each of the electrodes 92a, 92b. When the batery cell 90 is operating as an energy source, electrons travel from the negative electrode 92b to the positive electrode 92a (represented by arrow A) and lithium ions travel from the negative electrode 92b to the positive electrode 92a (represented by the arrow B).

[0045] An energy storage system or batery pack is illustrated in Figures 2A-2L, is identified by reference numeral 110, and is at least generally in accord with the above-described batery pack 10. The energy storage system 110 includes an outer or batery pack housing 112, along with a plurality of batery modules (e.g., at least generally in accord with the batery modules 30 shown in Figures 1 A and IB) that are disposed within (e.g., enclosed by) the battery pack housing 112. Any appropriate number of batery modules may be utilized by the batery pack 110 (three being shown in Figures 2G and 2H, and disposed in a vertically-extending stack). An interior of each batery module may be characterized as being at least substantially fluidly isolated from an internal chimney 160 (as well as possibly an interior of the batery pack housing 112) under normal operating conditions.

[0046] Each batery module includes a batery module housing 132, along with a plurality of batery cells 180 (Figure 21) that are disposed within (e.g., enclosed by) the corresponding batery module housing 132. These batery cells 180 (e.g., a lower portion thereof) may be disposed within a corresponding contact ring 184 (e.g., Figures 2H and 21) of a thermal management system (e.g., in accord with U.S. Patent No. 10,998,590), where vapor paths 186 for the thermal management system may be defined by the spacing between multiple contact rings 184 that contact one another. In any case, an end 182 of each batery cell 180 may include both the positive and negative terminals for the batery cell 180. [0047] The batery pack housing 112 includes an upper or top wall 114 and a lower or botom wall 116 that are disposed in vertically spaced relation to one another. Typically the batery pack housing 112 will be orientated such that its lower wall 116 is disposed on an appropriate support (and such that the upper wall 114 will then be disposed at a higher elevation; e.g., inverted from the views shown in Figures 2A, 2B, and 2D-2H). A first sidewall 120 and a second sidewall 122 of the batery pack housing 112 each extend between the upper wall 114 and lower wall 116. A pair of end walls 118 of the batery pack housing 112 extend between both the upper wall 114 and the lower wall 116, as well as between the first sidewall 120 and the second sidewall 122 to define the enclosed interior for the batery pack 110 that receives the various batery modules. The spacing between these end walls 118 may be characterized as corresponding with a length dimension of the batery pack housing 112, the spacing between the first sidewall 120 and the second sidewall 122 may be characterized as corresponding with a width dimension of the batery pack housing 112, and the spacing between the upper wall 114 and the lower wall 116 may be characterized as corresponding with a height dimension of the batery pack housing 112.

[0048] The battery module housing 132 of each batery module will typically be of a common configuration, and as such details of the batery module housing 132 will be discussed in the singular. The batery module housing 132 includes an upper or top wall 134 and a lower or botom wall 136 that are disposed in vertically spaced relation to one another. A first sidewall 140 and a second sidewall 142 of the batery module housing 132 each extend between the upper wall 134 and lower wall 136. A pair of end walls of the batery module housing 132 each extend between both the upper wall 134 and the lower wall 136, as well as between the first sidewall 140 and the second sidewall 142 to define an enclosed interior. The spacing between the end walls may be characterized as corresponding with a length dimension of the batery module housing 132, the spacing between the first sidewall 140 and the second sidewall 142 may be characterized as corresponding with a width dimension of the batery module housing 132, and the spacing between the upper wall 134 and the lower wall 136 may be characterized as corresponding with a height dimension of the batery module housing 132. Each end wall 118 of the batery pack housing 112 would face and be disposed beyond the corresponding end wall of each of the batery modules.

[0049] The batery modules may be disposed in a stack that extends in the vertical dimension (corresponding with the spacing between the upper wall 114 and the lower wall 116 of the batery pack housing 112). Stated another way, the various batery modules are disposed in vertically spaced (or overlying) relation to one another within the stack. However, the batery modules may be oriented relative to each other in any suitable manner. In any case, each adjacent pair of battery modules of the battery pack 110 may be separated by an open space within the stack (e. g. , a minimum gap of 10 mm for at least certain configurations/ applications), of any suitable spacing.

[0050] The first sidewall 140 of each battery module faces or projects toward, and is spaced from the first sidewall 120 of the battery pack housing 112. Similarly, the second sidewall 142 of each battery module faces or projects toward, and may be spaced from the second sidewall 122 of the battery pack housing 112. In the case of the battery pack 110, there is a single exhaust compartment or chimney 160 and it is located in the spacing between the first sidewall 120 of the battery pack housing 112 and the first sidewall 140 of each of the battery modules within the stack (e.g., Figures 2G and 2H).

[0051] Part of the first sidewall 140 of the battery pack housing 120 may be characterized as including a chimney plate or cover 164 (Figures 2A-2C) that encloses a space (an internal chimney 160) into which one or more battery modules may direct a discharge in a thermal or other over-pressurization event or the like. Figures 2D-2F illustrate that the first sidewall 140 of each of the three battery modules of the battery pack 110 includes a pair of module outlets 146 (e.g., apertures) that are closed by cover 148 (e.g., rupture tape) during normal conditions (e.g., when the pressure within a given battery module has not exceeded a certain pressure threshold). In other example embodiments, the cover 148 could be a one-way umbrella valve. For example, burst tape may be formed as an umbrella. In an example embodiment, the umbrella valve may comprise a outside diameter that is large enough to facilitate high flow rate of gasses and ejecta. In an example embodiment, the outside diameter of the opening is oval shaped, or has an aspect ratio that is longer than it is wide. The module outlets 146 from the battery modules are aligned with the chimney 160. Each module outlet 146 is designed to rupture on exposure to at least a certain pressure within the interior of the corresponding battery module (e.g., during a thermal runaway), and a pressurized flow may then be directed into the chimney 160.

[0052] A pair of chimney exhaust valves 162 are fluidly connected with the chimney

160 (e.g., Figure 2D). A discharge head of each exhaust valve 162 is disposed on the external side of the chimney plate 164 (and thereby on the exterior of the battery pack 110). Each exhaust valve 162 is seated in and/or extends through an aperture 166 in the chimney plate 164 to fluidly connect with the chimney 160. A shield 168 is disposed over the discharge head of the two exhaust valves 162. This shield 168 includes a closed end 170 and an oppositely disposed open or discharge end 172. A flow out of the chimney 160 through the exhaust valves 162 is directed out of the open end 172 of the shield 168. In the illustrated embodiment the open or discharge end 172 of the shield 168 directs a flow exiting the chimney 160 in a downward direction into the environment in which the battery pack 110 is located (assuming that the battery pack 110 is being supported on its lower wall 116). In the illustrated embodiment, the exhaust valves 162 are disposed in a "lower" portion of the battery pack 110 (again when the battery pack 110 has its lower wall 116 on an appropriate supporting surface), with the exhaust valves 162 being closer to the bottom call 116 than the top wall 114.

[0053] At least one thermal barrier or thermal insulator 150 may be disposed between each adjacent pair of battery modules within the stack of the battery pack 110. For instance and referring to Figures 2J-2L, a mica sheet may be secured to the external surface of the lower wall 136 of each battery module in the stack that faces or projects toward an upper wall 134 of an adjacent battery module in the stack of the battery pack 110. Moreover, one or more segments 152 of an intumescent material may be appropriately secured relative to a corresponding battery module in the stack of the battery pack 110 so as interface with the open space between an adjacent pair of battery modules in the stack of the battery pack 110. Such a segment(s) 152 may expand to fill all or a portion of the open space between an adjacent pair of battery modules in the stack of the battery pack 110 upon exposure to at least a certain temperature, which should further thermal isolate adjacent pairs of battery modules in the stack of the battery pack 110 from one another (e.g., particularly for the case where only one of the two adjacent modules is undergoing a thermal event, such as a thermal runaway) and that may further facilitate directing a flow into the internal chimney 160.

[0054] An energy storage system or battery pack is illustrated in Figures 3A-3I, is identified by reference numeral 210, and is at least generally in accord with the above-described battery pack 10. The energy storage system 210 includes an outer or battery pack housing 212, along with a plurality of battery modules (e.g., at least generally in accord with the battery modules 30 shown in Figures 1 A and IB) that are disposed within (e.g., enclosed by) the battery pack housing 212. Any appropriate number of battery modules may be utilized by the energy storage system 210 (e.g., over 20 battery modules disposed within a stack). An interior of each battery module may be characterized as being at least substantially fluidly isolated from a pair of internal chimneys 270 (as well as possibly an interior of the battery pack housing 212) under normal operating conditions.

[0055] The battery pack housing 212 includes an upper or top wall 214 and a lower or bottom wall 216 that are disposed in vertically spaced relation to one another. A first sidewall 220 and a second sidewall 222 of the battery pack housing 212 each extend between the upper wall 214 and lower wall 216. A pair of end walls 218 of the battery pack housing 212 extend between both the upper wall 214 and the lower wall 216, as well as between the first sidewall 220 and the second sidewall 222 to define the enclosed interior for the energy storage system 210 that receives the battery modules. The spacing between these end walls 218 may be characterized as corresponding with a length dimension of the battery pack housing 212, the spacing between the first sidewall 220 and the second sidewall 222 may be characterized as corresponding with a width dimension of the battery pack housing 212, and the spacing between the upper wall 214 and the lower wall 216 may be characterized as corresponding with a height dimension of the battery pack housing 212. The energy storage system 210 may be characterized as being in the form of a tower. Although the noted internal chimneys 270 could extend along an entirety of each side of the battery pack 210, each internal chimney 270 in the illustrate configuration extends along only part of each side of the battery pack 210 (coinciding with the width dimension of the chimney 270).

[0056] The battery modules are disposed in a stack that extends in the vertical dimension (corresponding with the spacing between the upper wall 214 and the lower wall 216 of the battery pack housing 212). Stated another way, the various battery modules are disposed in vertically spaced (and/or overlying) relation to one another within the stack. In any case, each adjacent pair of battery modules of the battery pack 110 may be separated by an open space within the stack (e.g., a minimum gap of 10 mm for at least certain configurations/applications). Figures 3D and 3E illustrate what may be characterized as a plurality of battery module receivers 260 that are disposed in a stack (the full stack being shown in Figure 3D; only part of the stack being shown in Figure 3E). The lower wall of each battery module includes a thermal barrier or thermal insulator 250 (Figures 3D and 3E). For instance, a mica sheet may be secured to the external surface of the lower wall of each battery module in the stack that faces or projects toward an upper wall of an adjacent battery module in the stack of the energy storage system 210. Moreover, one or more segments of an intumescent material may be appropriately secured relative to a corresponding battery module in the stack of the energy storage system 210 so as interface with the open space between an adjacent pair of battery modules in the stack of the energy storage system 210. Such a segment(s) may expand to fill all or a portion of the open space between an adjacent pair of battery modules in the stack of the energy storage system 210 upon exposure to at least a certain temperature, which should further thermal isolate adjacent pairs of battery modules in the stack of the energy storage system 210 from one another (e.g., particularly for the case where only one of the two adjacent modules is undergoing a thermal event, such as a thermal runaway) and that may further facilitate directing a flow into one or more of the internal chimneys 270.

[0057] The energy storage system 210 includes a pair of internal exhaust compartments or chimneys 270 - one associated with the first sidewall 220 of the battery pack housing 212 and another associated with the second sidewall 222 of the battery pack housing 212 (a separate exhaust manifold 272 being associated with each chimney 270 to provide an exhaust flowpath from the corresponding chimney 270 to atmosphere or the exterior of the battery pack housing 212). In this regard, each battery module includes/is associated with a pair of module vents 240 in the case of the energy storage system 210 - one associated with each of the battery module sidewalls (e.g., Figures 3B-3E). Referring to Figures 3D-3G, each module vent 240 includes a frame 242 and a plurality module outlets/covers 246. An interior side of one of the vents 240 is illustrated in Figure 3F. Each module outlet/cover 246 includes a score or perforation 248 (only one shown in relation to one module outlet/cover 246 in Figure 3F) on its interior side to provide a predetermined burst pressure or the like. The module outlets/covers 246 are scored/perforated such that each module outlet/cover 246 has a smaller burst pressure on its interior side compared to its exterior side. That is, a given module outlet/cover 246 should open or burst (e.g., change from a closed configuration to an open configuration) when exposed to at least a first pressure within its corresponding battery module, but should remain in a closed configuration when exposed to a higher pressure on its exterior side (for instance, if another battery module in the energy storage system 210 is undergoing a thermal runaway and one or more of its module outlets/covers 246 has opened or ruptured (e.g., disposing such a module outlet 246 in an open configuration)).

[0058] Both internal chimneys 270 are of a similar configuration, and as such only the chimney 270 associated with the second side of the battery pack housing 220 will be addressed. The second sidewall 222 of the battery pack housing 212 may be characterized as including a chimney plate or cover 222a (Figure 3A) that encloses a space (the corresponding chimney 270) into which one or more battery modules may direct a discharge in the case a thermal event, an over-pressurization event, or the like. The "depth" of the chimney 270 is defined by a pair of oppositely disposed interior end walls 224 (one such end wall 224 being illustrated in Figure 3C). The corresponding module vents 240 of the battery module in the stack for the energy storage system 210 could collectively define a "back wall" of the chimney 270 (e.g., Figures 3B and 3C). However, the chimney 270 could include a back wall 280 having a plurality of vents 282 (Figure 3H), where this back wall 280 would be disposed between the various corresponding module vents 240 and the chimney cover plate 222a (Figure 3A). [0059] As previously noted, a separate exhaust manifold or header 272 is provided for each chimney 270, and these exhaust headers 272 are at least generally adjacent to the top wall 214 of the battery pack housing 212 (in any case at the "top" of the corresponding chimney 270). A plurality of flow ports or channels 274 (3 shown) extend through each exhaust header 272 (e.g., Figure 3H). One end of each flow channel 274 interfaces with the upper end of the corresponding chimney 270, while the opposite end of each flow channel 274 interfaces with the environment/atmosphere. As such, exhaust flow through each flow channel 274 of the exhaust header 272 may first proceed in a first direction (e.g., vertically) from the corresponding internal chimney 270, and may then proceed in a different second direction (e.g., laterally) to discharge flow from the corresponding internal chimney 270 to atmosphere (e.g., each flow channel 274 may be at least generally in the configuration of a 90° elbow or the like). [0060] Instead of using a rupturable member (module outlet/ cover) between the interior of the battery modules and an internal chimney 270, each battery module could "vent" to an internal chimney via an appropriate valve (e.g., a pressure relief valve; a valve that changes from a closed configuration to an open configuration upon exposure to a threshold pressure). Such a configuration is shown in Figure 31 in the form of a "shorter" tower/battery pack housing 212'. The chimney 270' in this case includes a solid back wall 280', but with the corresponding exhaust header 272 (not shown) still being disposed in proximity to the upper wall 214. A plurality of valves 284 extend through the back wall 280' and with their corresponding discharge head being disposed within the chimney 270'. An inlet to each valve 284 may be fluidly connected with a corresponding battery module. A pair of valves 284 (one at generally each of the two sides of the chimney 270') are associated with each battery module.

[0061] With reference now to Figures 3J and 3K, example chimney embodiments 310 are shown. For example, in one example embodiment, a chimney cover 364 is shown, with vent valves 362 in a deflector 368. In another example embodiment, a chimney 360 is shown with a burst seal 348 and a gasket 369 illustrated. In a further example embodiment, Figure 3L illustrates an exploded perspective view of an example chimney embodiment. In this example embodiment, a gasket 369 is located between a chimney cover 364 (similar to cover plate 164) and a pack chimney 360 (similar to chimney 160), with burst seals 348 (similar to cover 148) covering openings into the pack chimney. The chimney cover 364 may further comprise openings that are covered by vent valves 362 (similar to exhaust valves 162). The vent valves 362 configured to open under suitable conditions to allow ejecta from the chimney to exit to the environment outside the pack. In an example embodiment, the vent valves 362 are covered by a deflector 368 (similar to shield 168) causing any ejecta flowing through the vent valves 362 to be routed, through a cavity formed thereby between the deflector 368 and the chimney cover 364, in a desired direction.

[0062] The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and skill and knowledge of the relevant art, are within the scope of the present invention. The embodiments described hereinabove are further intended to explain best modes known of practicing the invention and to enable others skilled in the art to utilize the invention in such, or other embodiments and with various modifications required by the particular application(s) or use(s) of the present invention. It is intended that the appended claims be construed to include alternative embodiments to the extent permitted by the prior art.

[0063] Any feature of any other various aspects addressed in this disclosure that is intended to be limited to a "singular" context or the like will be clearly set forth herein by terms such as "only," "single," "limited to," or the like. Merely introducing a feature in accordance with commonly accepted antecedent basis practice does not limit the corresponding feature to the singular. Moreover, any failure to use phrases such as "at least one" also does not limit the corresponding feature to the singular. Use of the phrase "at least substantially," "at least generally," or the like in relation to a particular feature encompasses the corresponding characteristic and insubstantial variations thereof (e.g., indicating that a surface is at least substantially or at least generally flat encompasses the surface actually being flat and insubstantial variations thereof). Finally, a reference of a feature in conjunction with the phrase "in one embodiment" or the like does not limit the use of the feature to a single embodiment. [0064] As used herein, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Also, as used herein, the terms “coupled,” “coupling,” or any other variation thereof, are intended to cover a physical connection, an electrical connection, a magnetic connection, an optical connection, a communicative connection, a functional connection, a thermal connection, and/or any other connection. When language similar to "at least one of A, B, or C" or "at least one of A, B, and C" is used in the specification or claims, the phrase is intended to mean any of the following: (1) at least one of A; (2) at least one of B; (3) at least one of C; (4) at least one of A and at least one of B; (5) at least one of B and at least one of C; (6) at least one of A and at least one of C; or (7) at least one of A, at least one of B, and at least one of C.

Claims

CLAIMS What is claimed is:

1. An energy storage system comprising: an outer housing; a plurality of battery modules disposed within said outer housing, wherein each said battery module comprises: a battery module housing; a plurality of battery cells disposed within said battery module housing; and a module outlet from said battery module housing, wherein said module outlet comprises a closed configuration and an open configuration; an exhaust compartment contained within said outer housing, wherein an interior of each said battery module housing is separately connectable with said exhaust compartment when its corresponding said module outlet is in said open configuration; and an exhaust flowpath extending from said exhaust compartment to an exterior of said outer housing.

2. The energy storage system of claim 1, wherein said plurality of battery modules are disposed within a stack.

3. The energy storage system of claim 2, wherein said stack extends in a vertical dimension.

4. The energy storage system of claim 3, wherein each adjacent pair of battery modules are spaced from one another in said vertical dimension.

5. The energy storage system of any of claims 3-4, wherein said outer housing comprises a first outer housing sidewall, wherein said battery module housing of each said battery module comprises a first module housing sidewall that faces said first outer housing sidewall, and wherein said first module housing sidewall of each said battery module housing comprises said module outlet.

6. The energy storage system of claim 5, wherein said exhaust compartment is located between said first outer housing sidewall and said first module housing sidewall of each said battery module.

7. The energy storage system of any of claims 3-6, further comprising at least one thermal isolation barrier between each adjacent pair of battery modules within said stack.

8. The energy storage system of claim 7, wherein each said battery module housing comprises a first wall and an oppositely-disposed second wall that are spaced from one another in said vertical dimension, and wherein said at least one thermal isolation barrier is attached to said second wall of each said battery module housing that projects toward said first wall of an adjacent said battery module within said stack.

9. The energy storage system of any of claims 7-8, wherein said at least one thermal isolation barrier comprises a mica sheet.

10. The energy storage system of any of claims 3-9, further comprising an intumescent material disposed between each adjacent pair of battery module housings in said stack.

11. The energy storage system of claim 10, wherein there is an open space between each said adjacent pair of battery module housings when a corresponding said intumescent material is in a first configuration, and wherein said intumescent material expands to occupy at least part of a corresponding said open space when exposed to an elevated temperature.

12. The energy storage system of any of claims 3-11, further comprising at least one exhaust valve at least partially disposed on said exterior of said outer housing, wherein said exhaust flowpath comprises said at least one exhaust valve.

13. The energy storage system of claim 12, further comprising a shield disposed over said at least one exhaust valve, said shield comprising an open end and a closed end.

14. The energy storage system of claim 13, wherein said open end projects in a downward direction and said closed end is disposed at a higher elevation in said vertical dimension.

15. The energy storage system of any of claims 12-14, wherein said at least one exhaust valve is closer to a bottom wall of said outer housing compared to a top wall of said outer housing.

16. The energy storage system of any of claims 3-11, further comprising an exhaust manifold disposed located vertically above said exhaust compartment, wherein said exhaust manifold comprises said exhaust flowpath.

17. The energy storage system of claim 16, wherein said exhaust flowpath extends upwardly and then laterally in progressing between said exhaust compartment and said exterior of said outer housing.

18. The energy storage system of any of claims 1-17, wherein each said battery module housing comprises a plurality of said module outlets.

19. The energy storage system of any of claims 1-18, wherein each said module outlet changes from said closed configuration to said open configuration in response to a pressure increase within an interior of a corresponding said battery module housing.

20. The energy storage system of any of claims 1-19, wherein each said module outlet comprises at least one of a rupturable burst tape or a rupturable paper.

21. The energy storage system of any of claims 1-19, wherein each said module outlet comprises a cover which is scored.

22. The energy storage system of claim 21, wherein each score of said cover of each said module outlet is disposed within an interior of a corresponding said battery module housing.

23. The energy storage system of any of claims 1-19, wherein each said module outlet comprises a valve.

24. The energy storage system of any of claims 1-19, wherein a first pressure within an interior of each said battery module housing is required to change its corresponding said module outlet from said closed configuration to said open configuration, wherein a second pressure on an exterior of each said battery module housing is required to change its corresponding said module outlet from said closed configuration to said open configuration, and wherein said second pressure is greater than said first pressure.

25. The energy storage system of any of claims 1-24, wherein an interior of a given said battery module housing is at least substantially fluidly isolated from said exhaust compartment when each said module outlet of said battery module housing is in said closed configuration.

26. The energy storage system of any of claims 1-25, wherein an interior of a given said battery module housing is fluidly connected with said exhaust compartment when at least one said module outlet of said battery module housing is in said open configuration.

27. The energy storage system of any of claims 1-26, wherein said energy storage system includes a single said exhaust compartment.

28. The energy storage system of any of claims 1-27, wherein said exhaust compartment is a chimney.

29. The energy storage system of any of claims 1-26, wherein said energy storage system comprises a pair of said exhaust compartments, wherein one said exhaust compartment is on a common first side of said plurality of battery modules, and wherein the other said exhaust compartment is on a common second side of said plurality of battery modules, wherein said common first side of said plurality of battery modules and said common second side of said plurality of battery modules are oppositely disposed.