Vented battery module and method

Abstract

A battery module and related methods are disclosed. In one aspect, the battery module includes a thermal isolation structure comprising a structural support plate and an aerogel layer. An embodiment of the thermal isolation structure is shown including a module cover contact located on an upper end of the structural support plate.

Description

[Technical Field]

[0001] Priority claims This application claims the benefit of U.S. Patent Application No. 63 / 436,015, filed December 29, 2022, which is incorporated herein by reference in its entirety.

[0002] Technical Field The present disclosure generally relates to materials, systems, and methods for preventing or mitigating thermal events, such as thermal runaway problems, in energy storage systems. In particular, the present disclosure provides thermal barrier materials. The present disclosure further relates to battery modules or packs having one or more battery cells that include the thermal barrier materials, as well as systems that include these battery modules or packs. The generally described embodiments may include aerogel materials. [Background technology]

[0003] Lithium-ion batteries (LIBs) are widely used in powering portable electronic devices such as mobile phones, tablets, laptops, power tools, and other high-current devices such as electric vehicles due to their high operating voltage, low memory effect, and high energy density compared to conventional batteries. However, safety concerns have arisen due to the susceptibility of LIBs to catastrophic failure under "abuse conditions," such as when rechargeable batteries are overcharged (charged beyond their design voltage), over-discharged, or operated or exposed to high temperatures and pressures. Summary of the Invention

[0004] Effective insulation and heat dissipation strategies are needed to address these and other technical challenges in LIBs to prevent the occurrence of cascading thermal runaway events. [Brief explanation of the drawings]

[0005] [Figure 1A] 1 illustrates an isometric view of a battery module according to some embodiments. [Figure 1B] 1 illustrates another isometric view of a battery module according to some embodiments. [Figure 2A] 1 illustrates another isometric view of a battery module according to some embodiments. [Figure 2B] 1 illustrates a cross-sectional view of a battery module according to some embodiments. [Figure 2C] 1 illustrates another isometric view of a battery module according to some embodiments. [Figure 3A] 1 illustrates another isometric view of a battery module according to some embodiments. [Figure 3B] 1 illustrates another isometric view of a battery module according to some embodiments. [Figure 4A] 1 illustrates another isometric view of a battery module according to some embodiments. [Figure 4B] 1 illustrates another isometric view of a battery module according to some embodiments. [Figure 5A] 1 illustrates another isometric view of a battery module according to some embodiments. [Figure 5B] 1 illustrates another isometric view of a battery module according to some embodiments. [Figure 6] 1 illustrates another isometric view of a battery module according to some embodiments. [Figure 7] 1 illustrates another isometric view of a battery module according to some embodiments. [Figure 8A] 1 illustrates another isometric view of a battery module according to some embodiments. [Figure 8B] 1 illustrates another isometric view of a battery module according to some embodiments. [Figure 9] 1 illustrates another isometric view of a battery module according to some embodiments. [Figure 10A] 1A-1C illustrate side and top views of a battery module according to some embodiments. [Figure 10B] 1 illustrates another top view of a battery module according to some embodiments. [Figure 11] 1 illustrates a method of forming a battery module according to some embodiments. [Figure 12] 1 illustrates an electronic device according to some embodiments. [Figure 13] 1 illustrates an electric vehicle according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0006] The following description and drawings sufficiently describe certain aspects to enable those skilled in the art to practice them. Other aspects may incorporate structural, logical, electrical, process, and other changes. Portions and features of some aspects may be included in, or substituted for, portions and features of other aspects. Claimed aspects encompass all available equivalents of those claims. In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which specific embodiments are shown by way of illustration and by way of which the disclosure may be practiced. It is to be understood that other aspects may be utilized and structural changes may be made without departing from the scope of the present disclosure.

[0007] overview The present disclosure is directed to a stack (e.g., a battery module or battery pack) of battery cells (e.g., lithium ion cells) with channels designed to guide ejections (e.g., gases or particles) from the battery cells during a thermal runaway event. The channels are formed in multiple cover layers disposed on the stack of battery cells. The channels minimize damage to the stack caused by the ejections by directing thermal runaway ejections away from mechanically weak portions of the battery cells (e.g., vents) and away from the stack.

[0008] In one embodiment, the battery pack's multiple cover layers include a first layer including holes (e.g., vent holes) aligned with mechanically weak portions of the battery cells to accommodate thermal runaway ejecta. The first layer may further include holes for receiving battery terminals such that the first layer is flush with the battery terminals. In this compact configuration, the first layer occupies the same plane as the battery terminals rather than occupying additional space above them. This configuration efficiently utilizes the limited space above the stack of cells in the battery pack or module. The first layer may be an insulating layer, a resilient layer, a rigid layer, or a combination thereof. In one embodiment, the first layer may be an aerogel layer that prevents heat transfer from a cell experiencing thermal runaway to other cells in the battery pack that are not experiencing thermal runaway.

[0009] In one embodiment, the plurality of cover layers further includes a second layer including a channel space for guiding thermal runaway effluent. The channel space of the second layer is aligned with the hole of the first layer. Due to the alignment between the channel space of the second layer and the vent hole of the first layer, the thermal runaway effluent is guided through the channel space and away from the stack. The second layer may further include holes aligned with the battery terminals, similar to the first layer. The second layer may be an insulating layer, an elastic layer, or a rigid layer. In one embodiment, the second layer may be a foam layer that provides elasticity (e.g., reversible compressibility) to the battery housing surrounding the battery stack.

[0010] In one embodiment, the channel space of the second layer includes a tube configured and sized to fit within the channel space. The tube within the channel space is disposed in and protected by the second layer. The tube can be further protected from mechanical damage if the second layer is an elastic layer. The tube further enhances protection of the battery cell against thermal runaway ejecta, particularly against damage caused by impact from thermal runaway ejecta. The channel can be selected from, but is not limited to, mica pipe, stainless steel pipe, or aluminum pipe.

[0011] In one embodiment, the plurality of cover layers further includes a third layer that is free of holes and channel spaces. The third layer can function as a barrier to prevent thermal runaway ejecta from damaging components adjacent to the battery stack, such as the passenger compartment of an electric vehicle. In one embodiment, the third layer can be a rigid layer selected from an aerogel plate, a mica plate, a stainless steel plate, a titanium alloy plate, a titanium plate, or any other rigid layer that resists damage from (and reduces the spread of) thermal runaway ejecta.

[0012] In one embodiment, the plurality of cover layers further includes a fourth layer. The fourth layer can add an additional layer of protection between the channel and the electrical device of the battery stack. The electrical device can include, but is not limited to, bus bars, electrical connectors, wires, sensors, and battery management circuits. The fourth layer can be disposed between the first and second layers or between the second and third layers, thereby separating the electrical device from the ventilation channel. In other words, the fourth layer can be disposed between the electrical device and the ventilation channel. The fourth layer can be an insulating layer, an elastic layer, or a rigid layer. In one embodiment, the fourth layer can be the same aerogel layer as the first layer.

[0013] In one aspect, the battery cell stack is enclosed by a housing and a housing lid. Multiple cover layers of the battery stack can be disposed between the battery stack and the housing lid or between the battery stack and a wall (e.g., a sidewall) of the housing. Channel spaces within the multiple cover layers direct thermal runaway ejecta to the outside of the housing. In some aspects, the channels can direct thermal runaway ejecta to the side or bottom of the housing, or in any direction that reduces or minimizes exposure of vulnerable components (e.g., electrical devices, battery management circuits, integrated circuits) to the thermal runaway ejecta and its associated damaging effects.

[0014] In one aspect, multiple battery cell stacks can be disposed in a single housing. The multiple battery cell stacks can share one or more of the first layer, the second layer, the third layer, and the fourth layer. In one aspect, the multiple battery cell stacks can each have a first layer and a second layer and share the third layer and the fourth layer. The channels of the multiple battery cell stacks can extend into a trunk within the housing, through which thermal runaway ejecta is directed to the outside of the housing.

[0015] As described in various aspects below, the materials used in the cover layers described below, such as the insulating material in the insulating layers, the rigid material in the rigid layers, and the elastic material in the elastic layers, can be used in battery modules to compartmentalize individual cells or groups of cells within a battery device. Multiple battery cells combined together are referred to as battery modules in this disclosure. However, the described devices and methods can be used with any of several types of multiple cell arrangements, which may be referred to as battery packs, battery systems, etc.

[0016] The insulating materials described below can be used as the sole heat-resistant layer or in combination with other layers that provide additional functionality to the multi-layer construction, such as mechanical strength, compressibility, or heat dissipation / conduction.

[0017] I. Materials for the insulating layer The insulating layers described herein reliably contain and control heat flow from heat-generating components within small spaces, providing safety for such products in the electronic, industrial, and automotive technologies and preventing flame propagation thereto. In many aspects of the present disclosure, the insulating layers described herein can function as flame / fire deflection layers by themselves or in combination with other materials that enhance their ability to contain and control heat flow. In one aspect, the insulating layer itself is flame and / or hot gas resistant and may further include entrained particulate materials or other types of additives or layers that modify or enhance heat containment and control.

[0018] One embodiment of a highly effective insulating layer comprises aerogels, which are characterized by their structure: low density, open cell structure, and large surface area (often over 900 m²). 2 This paper describes a class of materials based on their thermal insulating properties (e.g., pore sizes of 1000 kJ / g or greater) and sub-nanometer scale pore sizes. The pores may be filled with a gas, such as air. Aerogels can be distinguished from other porous materials by their physical and structural properties. Aerogel materials are exemplary insulating materials, but the invention is not limited thereto. Other thermal insulating material layers may also be used in embodiments of the present disclosure.

[0019] Selected aspects of aerogel formation and properties are described. In some aspects, precursor materials are gelled to form a network of solvent-filled pores. The solvent is then extracted, leaving a porous matrix. A variety of different aerogel compositions are known, and they may be inorganic, organic, and inorganic / organic hybrids. Inorganic aerogels are generally based on metal alkoxides and include materials such as silica, zirconia, alumina, and other oxides. Organic aerogels include, but are not limited to, urethane aerogels, resorcinol formaldehyde aerogels, and polyimide aerogels.

[0020] Inorganic aerogels can generally be formed from metal oxide or metal alkoxide materials. The metal oxide or metal alkoxide materials can be based on the oxide or alkoxide of any metal capable of forming an oxide. Such metals include, but are not limited to, silicon, aluminum, titanium, zirconium, hafnium, yttrium, vanadium, cerium, and the like. Inorganic silica aerogels are traditionally made via the hydrolysis and condensation of silica-based alkoxides (e.g., tetraethoxysilane) or via the gelation of silicic acid or water glass. Other relevant inorganic precursor materials for silica-based aerogel synthesis include, but are not limited to, metal silicates such as sodium silicate or potassium silicate, alkoxysilanes, partially hydrolyzed alkoxysilanes, tetraethoxysilane (TEOS), partially hydrolyzed TEOS, condensation polymers of TEOS, tetramethoxysilane (TMOS), partially hydrolyzed TMOS, condensation polymers of TMOS, tetra-n-propoxysilane, partially hydrolyzed and / or condensation polymers of tetra-n-propoxysilane, polyethylsilicate, partially hydrolyzed polyethylsilicate, monomeric alkylalkoxysilanes, bis-trialkoxyalkyl or arylsilanes, polyhedral silsesquioxanes, or combinations thereof.

[0021] In certain embodiments of the present disclosure, prehydrolyzed TEOS, such as Silbond H-5 (SBH5, Silbond Corp), which is hydrolyzed to a water / silica ratio of about 1.9 to 2, may be used commercially or may be further hydrolyzed before being incorporated into the gelation process. Partially hydrolyzed TEOS or TMOS, such as polyethyl silicate (Silbond 40) or polymethyl silicate, may also be used commercially or may be further hydrolyzed before being incorporated into the gelation process.

[0022] Inorganic aerogels can also include gel precursors containing at least one hydrophobic group, such as alkyl metal alkoxides, cycloalkyl metal alkoxides, and aryl metal alkoxides, which can impart or improve certain properties to the gel, such as stability and hydrophobicity. Inorganic silica aerogels, specifically, can include hydrophobic precursors such as alkyl silanes or aryl silanes. The hydrophobic gel precursor may be used as the primary precursor material to form the framework of the gel material. However, hydrophobic gel precursors are more commonly used as co-precursors in combination with simple metal alkoxides to form amalgam aerogels. Hydrophobic inorganic precursor materials for silica-based aerogel synthesis include, but are not limited to, trimethylmethoxysilane (TMS), dimethyldimethoxysilane (DMS), methyltrimethoxysilane (MTMS), trimethylethoxysilane, dimethyldiethoxysilane (DMDS), methyltriethoxysilane (MTES), ethyltriethoxysilane (ETES), diethyldiethoxysilane, dimethyldiethoxysilane (DMDES), ethyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane (PhTES), hexamethyldisilazane, and hexaethyldisilazane. Any derivatives of any of the above precursors may also be used, particularly certain polymers of other chemical groups may be added to or crosslinked with one or more of the above precursors.

[0023] Organic aerogels are generally formed from carbon-based polymer precursors. Such polymeric materials include, but are not limited to, resorcinol formaldehyde (RF), polyimides, polyacrylates, polymethyl methacrylates, acrylate oligomers, polyoxyalkylenes, polyurethanes, polyphenols, polybutadiene, trialkoxysilyl-terminated polydimethylsiloxanes, polystyrenes, polyacrylonitriles, polyfurfural, melamine-formaldehyde, cresol formaldehyde, phenol-furfural, polyethers, polyols, polyisocyanates, polyhydroxybenzenes, polyvinyl alcohol dialdehyde, polycyanurates, polyacrylamides, various epoxies, agar, agarose, chitosan, and combinations thereof. In one aspect, organic RF aerogels are typically prepared from the sol-gel polymerization of resorcinol or melamine with formaldehyde under alkaline conditions.

[0024] Organic / inorganic hybrid aerogels are primarily composed of organically modified silica ("ormosil") aerogels. These ormosil materials contain organic components covalently bonded to the silica network. Ormosils are typically formed by the hydrolysis and condensation of organically modified silanes R-Si(OX)3 with conventional alkoxide precursors Y(OX)4. In these formulas, X can represent, for example, CH3, CH5, CH7, or CH9; Y can represent, for example, Si, Ti, Zr, or Al; and R can be any organic fragment, such as methyl, ethyl, propyl, butyl, isopropyl, methacrylate, acrylate, vinyl, or epoxide. Additionally, the organic components in ormosil aerogels can be dispersed throughout the silica network or chemically bonded to it.

[0025] Aerogels can be formed from flexible gel precursors. Various flexible layers, including flexible fiber-reinforced aerogels, can be easily combined and shaped to obtain a preform that, when mechanically compressed along one or more axes, provides an object with high compressive strength along any of those axes.

[0026] One method of aerogel formation involves batch casting. Batch casting involves catalyzing an entire volume of sol to simultaneously induce gelation throughout that volume. Gel formation techniques involve adjusting the pH and / or temperature of a dilute metal oxide sol to a point where gelation occurs. Materials suitable for forming inorganic aerogels include oxides of most metals capable of forming oxides, such as silicon, aluminum, titanium, zirconium, hafnium, yttrium, and vanadium. Particularly preferred are gels formed primarily from alcoholic solutions of hydrolyzed silicate esters (alcogels) due to their ready availability and low cost. Organic aerogels can also be made from melamine formaldehyde, resorcinol formaldehyde, and the like.

[0027] In one aspect, the aerogel material may be monolithic or continuous throughout the structure or layer. In another aspect, the aerogel material may include a composite aerogel material having aerogel particles mixed with a binder. Other additives may be included in the composite aerogel material, including, but not limited to, surfactants to aid in the dispersion of the aerogel particles within the binder. The composite aerogel slurry may be applied to a support such as a mesh, felt, or web and then dried to form a composite aerogel structure.

[0028] The aerogel may be organic, inorganic, or a mixture thereof. In some embodiments, the aerogel comprises a silica-based aerogel. One or more layers within the thermal barrier may include a reinforcing material. The reinforcing material may be any material that provides resilience, compliance, or structural stability to the aerogel material. Embodiments of the reinforcing material include, but are not limited to, open-cell macroporous framework reinforcement materials, closed-cell macroporous framework reinforcement materials, open-cell membranes, honeycomb reinforcement materials, polymeric reinforcement materials, and fibrous reinforcement materials such as, for example, staple fibers, woven materials, nonwoven materials, needled nonwovens, battings, webs, mats, and felts.

[0029] The reinforcing material can be selected from organic polymer-based fibers, inorganic fibers, carbon-based fibers, or combinations thereof. In various aspects, the inorganic fibers are selected from glass fibers, rock fibers, metal fibers, boron fibers, ceramic fibers, basalt fibers, or combinations thereof. In some aspects, the reinforcing material can include a reinforcement comprising multiple layers of material.

[0030] II. Materials for the Stiffness Layer In addition to the thermal insulating layer, the rigid layer in combination with the thermal insulating layer is effective in protecting components adjacent to the battery stack (e.g., the passenger compartment of an electric vehicle) during a thermal runaway event. The rigid layer effectively protects the battery components and associated electrical devices from the impact of particles in a thermal runaway ejecta. Examples of rigid materials used in the rigid layer include, but are not limited to, carbon fiber, graphite, silicon carbide, copper, stainless steel, aluminum, titanium, other metals, titanium alloys, other metal alloys, and combinations thereof.

[0031] An additional function of the rigid layer is to channel unwanted heat to a desired external location, such as external heat dissipation fins, a heat dissipation enclosure, or other external structure that dissipates the unwanted heat to the ambient air or other heat dissipation location (e.g., a heat exchanger, a heat sink). The heat dissipation function is particularly pronounced when the rigid layer is a rigid metal plate. In one aspect, one or more thermally conductive layers help dissipate heat from localized thermal loads within the battery module or pack.

[0032] To aid in heat distribution and removal, in at least one embodiment, the thermally conductive layer is coupled to a heat sink. Various heat sink types and configurations, as well as various techniques for coupling the heat sink to the thermally conductive layer, are encompassed by the present disclosure. The present disclosure is not limited to the use of any one type of heat sink / coupling technique. In one aspect, at least one thermally conductive layer of the multilayer material disclosed herein may be in thermal communication with an element of a cooling system of a battery module or pack, such as a cold plate or cooling channel of the cooling system. In another example embodiment, the at least one thermally conductive layer may be in thermal communication with other elements of the battery pack, battery module, or battery system that can function as a heat sink, such as a wall of the pack, module, or system, or with other elements of the multilayer material disposed between battery cells. Thermal communication between the thermally conductive layer and the heat sink element in the battery system can enable the removal of excess heat from the cell(s) adjacent to the multilayer material to the heat sink, thereby reducing the impact, severity, or propagation of thermal events that may generate excess heat. In addition to removing heat, the thermally conductive layer can diffuse or dissipate heat from areas of high heat concentration to areas of low heat concentration.

[0033] III. Materials for the Elastic Layer In addition to the thermal insulating layer and the rigid layer, the multiple cover layers may further include one or more elastic layers to accommodate channels for use in ventilation. In some embodiments, a tube may be disposed within the channel. The tube further contains and redirects thermal runaway ejecta away from weak points in the battery pack. The elastic layer also accommodates mechanical stresses imposed on the battery module or pack during operation or under abuse conditions. In one embodiment, the elastic layer may absorb mechanical stress and strain (e.g., with an elastic modulus of less than 1 GPa, less than 100 MPa), thereby preventing mechanical stress from damaging the tube and / or the battery pack.

[0034] Materials for the elastic material layer may include, but are not limited to, foam, fiber, fabric, sponge, spring structure, rubber, polymer, etc. In one embodiment, the elastic material layer includes an aerogel layer, such as a monolithic aerogel layer, an aerogel plate, an aerogel blanket, a fiber-reinforced aerogel blanket, another aerogel layer, and combinations thereof. Additional elastic layers may be disposed adjacent to the battery cells or between the cells. In one embodiment, the elastic layer absorbs any volumetric expansion of one or more battery cells during normal operation. In one embodiment, cells may expand during charging and contract during discharging. In one embodiment, the elastic layer may also absorb permanent volumetric expansion caused by degradation and / or thermal runaway of any battery cell. In one embodiment, the elastic layer may be compressed to 5% to 95%, 10% to 90%, 30% to 90%, 40% to 85%, 60% to 80% of its original thickness, or any of the percentages described herein.

[0035] IV. Illustrative Embodiments A. Multiple Cover Layer(s) and Optional Channels 1A shows a battery module 100 that includes a channel defined by one or more cover layers. The channel formed in the cover layer(s) directs thermal runaway ejecta away from the battery module, thereby protecting the battery module components from damage.

[0036] 1A shows one embodiment of a battery module 100. The battery module 100 further includes a stack of battery cells 102 and a plurality of cover layers 110 including one or more of a first layer 116, a second layer 114, and / or a third layer 112, each of which is further described below.

[0037] In one embodiment, the stack of cells 102 includes individual lithium-ion cells 102A, 102B, 102C, and 102D (collectively referred to as a stack of cells 102). Several configurations of the lithium-ion cells 102 are possible. In one embodiment, the stack of lithium-ion cells 102 includes lithium-ion pouch cells or lithium-ion prismatic cells, although the invention is not limited thereto. Each of the cells 102 in FIG. 1A includes an electrical terminal 104.

[0038] 1A, a vent 106 is included in each cell 102A, 102B, 102C, 102D in the stack of cells 102. In the event of thermal runaway in a given cell 102, or in some cells in a stack of cells 102, the vent 106 directs hot gases and flames away from the cell 102. It is desirable to direct (and exhaust to the outside) any hot gases and flames in a direction away from the stack of cells 102 and any sensitive control components (e.g., toward the sides of the battery module) and to a safe location (e.g., away from the passenger compartment).

[0039] 1A embodiment includes multiple cover layers 110 on the side of the stack of lithium-ion cells that includes the electrical terminals 104. A first layer 116, a second layer 114, and a third layer 112 are stacked together on top of the cell 102 and associated vent 106 to form an enclosed channel 118 from the assembly of the various layers, such as the first layer 116, the second layer 114, and the third layer 112. The channel 118 and the spaces / pores in one or more adjacent layers are aligned.

[0040] A first layer 116 of the plurality of cover layers 110 is shown having holes 117 for receiving terminals 104 corresponding to cells 102A-102D of the stack of cells 102. The first layer 116 also defines vent holes 107 that are aligned with corresponding vents 106 of cells in the stack of cells 102.

[0041] A second layer 114 of the plurality of cover layers 110 corresponds to and is shown including holes 115 for receiving terminals 104. A channel 118 is defined in second layer 114. Channel 118 is aligned with vents 106 and vent holes 107.

[0042] The third layer 112 is shown to be continuous (i.e., does not define or otherwise include holes). The third layer 112 is intended to protect the components above the battery module 100 (passenger compartment) in abnormal conditions such as thermal runaway.

[0043] In one embodiment, the first layer 116, the second layer 114, and the third layer 112 of the plurality of cover layers 110 can be made of the same material. In one embodiment, the layers of the plurality of cover layers 110 include multiple materials for different layers. The layer adjacent to the channel 118 must be thermally insulating to facilitate channeling of hot gases and flames and prevent damage to the layer(s) (e.g., the second layer 114) due to exposure to thermal runaway ejecta. In one embodiment, one or more layers of the plurality of cover layers 110 include an aerogel layer. Other layers may include structural materials such as polymers, stainless steel, etc. In one embodiment, the structural material provides sufficient rigidity to withstand operating stresses without deformation. An example of a heat-resistant layer includes a mica-containing layer. An elastic material layer may be included to better accommodate packing within the subsequent battery housing (not shown). In one embodiment, the first layer 116 is an aerogel blanket, the second layer 114 is a foam material, and the third layer 112 is a mica plate. In one embodiment, the first layer 116 is an aerogel blanket, the second layer 114 is a foam material, and the third layer 112 is an aerogel plate.

[0044] In one aspect, layers 114 and 116 are aerogel layers, and layer 112 is a rigid layer containing a structural material. Although three layers 116, 114, and 112 are shown as components of the plurality of cover layers 110, the present invention is not limited thereto. In other aspects of the plurality of cover layers 110, less than three or more than three layers are included. The layers of the plurality of cover layers 110 can be connected, for example, by adhesives, stitching, taping, heat pressing, etc. In some aspects, at least a portion of the plurality of cover layers 110 fills the vertical space generated by the terminal 104, and thus uses the otherwise empty space between the upper part of the battery cell 102 and the upper part of the terminal 104.

[0045] In some aspects, the plurality of cover layers 110 are configured to define channels 118 (directed in the ventilation direction) that are configured to receive ventilation gas from the ventilation portion 106. In some aspects, the channels 118 are directed in the channel direction (e.g., the X direction). Similar to the ventilation direction of the ventilation portion 106 described above and as shown in FIG. 1A, the channels 118 and the corresponding channel direction (e.g., the X direction) can be directed so that the thermal runaway ejecta is directed away from combustible components such as the passenger compartment, weak electronic devices, rubber hoses, or other aspects of the vehicle that could otherwise be damaged by exposure to the thermal runaway ejecta. In some examples, the channel direction (e.g., the X direction) is substantially perpendicular to the ventilation direction (the explanation of which is found in the vertical arrow of FIG. 2B), but the present invention is not limited thereto. The battery module including the channels 118 described in the aspect of FIG. 1A and other aspects described below can be installed in any desired orientation in a device such as an electric vehicle, and any ventilation gas can be directed away from unwanted areas, giving the designer of the electric vehicle more options for orientation and location. Although an electric vehicle is used as an aspect, the present invention is not limited thereto. The redirection of the ventilation gas and the flame can also be applied to other battery-powered electric devices.

[0046] FIG. 1B illustrates a variation of the exemplary battery module depicted in FIG. 1A. In FIG. 1B, the channels 118 formed by adjacent layers as described above in FIG. 1A are filled with a sacrificial material 120. The sacrificial material 120 functions as a gap filler during normal operation of the battery module. The sacrificial material 120 can be burned away when vented to gas and flame. The sacrificial material layer can have a low heat of combustion. The sacrificial material 120 can include polymers, foams, fibers, other suitable materials that burn away with a low heat of combustion, and combinations thereof.

[0047] 1A provides benefits such as keeping the channel 118 sealed until a venting event occurs. One benefit of sealing the channel 118 is that dust or debris is excluded from the channel, the vent 106, and therefore the interior of the battery pack and battery stack.

[0048] Another benefit of the features shown in FIG. 1A related to the presence of the sacrificial material 120 includes helping the channels 118 maintain their shape within the multiple cover layers 110 until a thermal runaway occurs. In one embodiment, one or more of the multiple cover layers 110 includes an aerogel material. Some aerogel materials are highly thermally insulating but can be brittle. In one embodiment, the sacrificial material 120 burns away with no or limited residue and heat generation in the event of a vent or thermal runaway. In an alternative embodiment, the sacrificial material 120 absorbs heat as it burns away in the event of a vent or thermal runaway. The inclusion of the sacrificial material 120 helps maintain the integrity of the aerogel layer until a vent event occurs.

[0049] B. Multiple cover layer(s), channels, and tubes FIG. 2A shows an exploded perspective view of one embodiment of a battery module 200 including a tube disposed within a channel defined by multiple cover layers. In one embodiment, the tube is a separate component from the multiple cover layers. The tube provides protection to the battery module beyond that provided by the above-described embodiments. In some embodiments, the structure of the tube further confines and directs thermal runaway ejecta away from the battery components beyond the constraints and direction provided by the channel alone. For example, the tube can be used to prevent ejecta from passing through gaps between layers in the stack and / or from eroding portions of layers exposed to the ejecta.

[0050] 2A includes a stack of cells 202, including battery cells 202A, 202B, 202C, and 202D, and a plurality of cover layers 210, including a first layer 216, a second layer 214, and a third layer 212. The battery module 200 also includes a tube 220.

[0051] Cells 202A, 202B, 202C, and 202D (collectively, 202A-202D) in FIG. 2A are similar to the cells described above. As shown and described above, cells 202A-202D may each include a set of electrical terminals 204. Additionally, one or more of cells 202A-202D may individually include a vent 206. The above description of the vent applies to vent 206.

[0052] The plurality of cover layers 210 includes one or more cover layers, each of which may be selected for one or more protective functions. In the illustrated exemplary battery module 200, the plurality of cover layers 210 includes three cover layers: a first layer 216, a second layer 214, and a third layer 212, each of which is described in more detail below.

[0053] In some embodiments, the plurality of cover layers 210 are disposed on and / or over the side of the lithium-ion cells 202A-202D that includes the electrical terminals 204. In some embodiments, to minimize the space occupied by the plurality of cover layers 210 and / or to reduce the gap between the first layer 216 and the top surfaces of the cells 202A-202D, the first layer 216 may define holes 217 for receiving the terminals 204. In this manner, the first layer 216 may be adjacent to and in contact with the top surfaces of the cells 202A-202D facing the first layer 216.

[0054] First layer 216 shown in FIG. 2A includes vent hole 207. In some embodiments, vent hole 207 in first layer 216 is aligned with vents 206 in cells 202A-202D. Thus, similar to the embodiment described above in connection with FIG. 2B, vent hole 207 and vent hole 206 communicate to form an exit path (shown by the dashed line in FIG. 2B) from one or more of cells 202A-202D to a corresponding port in tube 220. The channel thus physically contains any ejecta migrating from one or more of cells 202A-202D into tube 220, providing protection to other components of battery module 200.

[0055] The second layer 214 may be disposed on the side of the first layer 216 opposite the cells 202A-202D. In some embodiments, the second layer 214 may be disposed between the first layer 216 and the third layer 212. The second layer 214 may be fabricated from a resilient material to provide cushioning to the battery module 200.

[0056] In some embodiments, second layer 214 defines a channel 218. Channel 218 is similar to channel 118 described above in connection with Figures 1A and 1B. As mentioned above, channel 218 may be configured and dimensioned to receive a tube 220, which is described in further detail below.

[0057] The third layer 212 may be located on the side of the second layer 214 opposite the first layer 216. Unlike the layers described above, the third layer 212 in this embodiment is continuous and lacks any holes and / or channels. The third layer 212 protects components adjacent to the battery module 200 (e.g., the passenger compartment) from damage due to thermal runaway ejecta from the battery cells 202.

[0058] While the layer materials are described above with respect to each individual layer, it will be understood that layers 216, 214, and 212 of the plurality of cover layers 210 can collectively be fabricated from the same material in some embodiments. In other embodiments, each layer of the plurality of cover layers 210 can include multiple materials, and / or different ones of layers 216, 214, and 212 can be fabricated from different materials. In some embodiments, a layer adjacent to channel 218 (e.g., layer 214, layer 114) can be a thermally insulating layer to facilitate heating of adjacent components. In one embodiment, one or more layers of the plurality of cover layers 210 include an aerogel layer. Any one or more of layers 216, 214, and 212 can include a structural material, e.g., a polymer or a metal such as stainless steel. An elastic material layer can be included in the plurality of cover layers 210. In some embodiments, the layers of the multiple cover layers 210 may be connected by adhesives, stitching, taping, heat pressing, mechanical bonding (eg, hook-and-loop connectors), among others.

[0059] In one embodiment, the first layer 216 of the plurality of cover layers 210 is an insulating layer, such as an aerogel layer. In one embodiment, the second layer 214 of the plurality of cover layers 210 is an elastic layer. In one embodiment, the third layer 212 of the plurality of cover layers 210 is a rigid layer.

[0060] As described above, battery module 200 includes tube 220 configured to fit within channel 218 of second layer 214. In some embodiments, second layer 214 is fabricated from a resilient (and optionally thermally insulating) material such that second layer 214 provides cushioning (e.g., via a modulus of elasticity less than 500 MPa) to tube 220. The cushioning provided by the resilient material used to form second layer 212 can function to prevent damage to battery module 200 from potential mechanical shocks.

[0061] 2A may include multiple sub-channels 221A, 221B, 221C, 221D (collectively 221) and a main channel port 222. The main channel port may terminate in an exit port 223 that discharges the jets away from weak spots in the battery pack and away from the passenger compartment.

[0062] In some embodiments, each of the sub-channels 221A, 221B, 221C, 221D corresponds to a corresponding vent 206 in the holes and cells of the first layer 216. The sub-channels 221 extend into the main tube portion 222. Referring to Figure 2C, the communication between the vent 206, the sub-channels 221, the main tube portion 222, and the exit port 223 forms an exit path, which directs the ejection to a safe location.

[0063] In one embodiment, the tube 220 is monolithic, such as by casting, although the invention is not so limited. Other embodiments may include separate sub-channels 221 that are threaded or otherwise attached to the main channel ports 222.

[0064] In one embodiment, the tube 220 is formed from a refractory material. Exemplary materials include, but are not limited to, ceramic, mica, resin, polymer, metal, carbon material, and combinations thereof. Metals that can be used for the tube 220 include stainless steel or titanium, which have the advantages of a high melting point and high corrosion resistance. In one embodiment, the first layer 216 is an aerogel blanket, the second layer 214 is a foam material, and the third layer 212 is a mica plate. In one embodiment, the first layer 216 is an aerogel blanket, the second layer 214 is a foam material, the third layer 212 is an aerogel plate, and the tube 220 is selected from a mica pipe, a stainless steel pipe, or an aluminum pipe.

[0065] 2B is a cross-sectional view of the battery module 200 taken in the X direction along the centerline of the tube 220. During a catastrophic event (e.g., thermal runaway), the battery cells 202 may become unstable and emit ejecta in the Z direction from the vent 206. The ejecta is directed into corresponding sub-channels 221A, 221B, 221C, and 221D (collectively 221) aligned with the vent 206. The ejecta is then redirected into the main channel port 222 in the X direction and subsequently exits through the exit port 223. The tube 220 thus contains and directs the ejecta through the multiple cover layers 210, away from weak areas of the battery pack, and away from the passenger compartment above the battery pack (in the Z direction).

[0066] 2C is a perspective view of the battery module 200 in a partially assembled configuration. The tube 220 is located within the second layer 214. In the illustrated embodiment, the main channel port 222 is less than or equal to the thickness of the second layer 214. An additional layer 219 is also shown in FIG. 2C. The additional layer 219 separates the tube 220 from an electrical cable (not shown) disposed between the additional layer 219 and the third layer 212. The electrical cable connects with the terminals 204 for charging and discharging the battery and for collecting battery test data.

[0067] C. Multiple cover layers with electrical connectors 3A shows an exemplary battery module 300 that includes many of the same elements described above in connection with battery modules 100 and 200, except that the multiple cover layers 310 of battery module 300 include an additional (e.g., fourth) cover layer 332 between the first and third layers. This fourth cover layer 332 separates the channels and electrical components. The fourth cover layer 332 provides additional protection for the electrical components associated with the battery by blocking thermal runaway ejections.

[0068] In the illustrated example, battery module 300 includes a stack of cells 302, including battery cells 302A, 302B, 302C, and 302D (collectively, 302A-302D). Battery module 300 includes a plurality of cover layers 310. The plurality of cover layers 310 includes a first layer 316, a second layer 314, a third layer 312, and a fourth layer 332. Battery module 300 also includes a tube 320.

[0069] 3A includes a corresponding electrical terminal 304 and vent 306. The electrical terminals 304 and vent 306 are similar to those described above, and the above description is equally applicable to these structures within the battery module 300.

[0070] As mentioned above, the battery cells 302A-302D may be lithium-ion battery cells, however, aspects of the present disclosure are applicable independent of battery chemistry or battery construction.

[0071] Similar to battery modules 100 and 200, battery module 300 includes multiple cover layers 310. Similar to multiple cover layers 110 and 210 described above in connection with FIGS. 1A-2B , multiple cover layers 310 include a first layer 316, a second layer 314, and a third layer 316. Similar to its analogous layers 116 and 216 described above in connection with battery modules 100 and 200, first layer 316 may optionally include holes 317 configured and dimensioned to align with electrical terminals 304. First layer 316 may optionally include vent holes 307 configured and dimensioned to align with vents 306. The configuration and function of holes 317 and vent holes 307 in first layer 316 are similar to the function and rationale of these structures described in connection with battery modules 100 and 200.

[0072] The second layer 314, like its analogous layers 114 and 214 described above in connection with battery modules 100 and 200, may optionally include holes 315 for receiving terminals 304. As described above in connection with analogous layers 114 and 214, the second layer 314 defines channels 318.

[0073] The third layer 312 is shown without any holes. Similar to the third layer 212 in the embodiment shown in Figures 2A-2C, the third layer 312 protects adjacent components of the battery module 300 from damage due to thermal runaway ejecta from the battery cells 302.

[0074] Similar to the multiple cover layers 110 and 210 in the embodiments of FIGS. 1A-2B above, the multiple cover layers 310 are all made of the same material in one embodiment. In one embodiment, the multiple cover layers 310 include multiple materials for different layers. A layer adjacent to the channel 318 can be a thermal insulating layer to prevent heat transfer from thermal runaway ejecta within the channel 318 or tube 320 to adjacent components, such as the battery cell 302. In one embodiment, one or more of the multiple cover layers 310 include an aerogel layer. Other layers can include structural materials, such as polymers or metals such as stainless steel. An elastic material layer can be included in the multiple cover layers 310. In one embodiment, the multiple cover layers 310 can be connected by adhesive, stitching, taping, heat pressing, other suitable connection methods, and combinations thereof.

[0075] 3A, the tube 320 is included as a separate component contained within the plurality of cover layers 310. In other words, the tube 320 is not part of the plurality of cover layers 310. The tube 320 fits within a channel 318 in the second layer 314. In one embodiment, the tube 320 is formed from a refractory material. Embodiment materials include, but are not limited to, mica, metal, and the like.

[0076] The embodiment of Figure 3A further includes an electrical connector 330. The electrical connector 330 couples the multiple terminals 304 together for further connection to device circuitry, an electric motor, or the like.

[0077] 3A, a fourth layer 332 is further included between the second layer 314 and the electrical connector 330 to protect the electrical connector 330 from heating during a thermal runaway. In the event of a thermal runaway, the heat of the ejecta may transfer heat to the tube 320, increasing the surface temperature of the tube 320. The increased surface temperature may damage the electrical connector 330. The fourth layer 332 between the tube 320 and the electrical connector 330 separates the hot surface of the tube 320 from the electrical connector 330.

[0078] The fourth layer 332 includes a material that provides suitable heat, fire, and electrical resistance. The fourth layer 332 may include materials similar to the first layers 116, 216, and 316 described above in connection with the battery modules 100, 200, and 300. In one embodiment, the fourth layer 332 includes an aerogel layer.

[0079] 3B provides an alternative arrangement of layers of the multiple cover layers 310. In one aspect, the electrical connector 330 is optionally disposed between the first layer 316 and the second layer 314. Accordingly, the fourth layer 332 is disposed between the first layer 316 and the second layer 314 so as to separate the channel 318 (and the tube 320 disposed therein) from the electrical connector 330. It may be advantageous to have a layer on at least one side of the electrical connector 330 to provide thermal, flame, and / or dielectric isolation of the electrical connector 330.

[0080] D. Cover Layers and Other Electrical Components 4A shows an exemplary battery module 400 that includes many of the same elements described above in connection with battery modules 100, 200, and 300, except that battery module 400 includes a battery management circuit 440 integrated with multiple cover layers 410. Multiple cover layers 410 protect battery management circuit 440 in the event of thermal runaway.

[0081] In the illustrated example, the battery module 400 includes a stack of battery cells 402, a plurality of cover layers 410 over the battery cells 402, a tube 420, and an electrical connector 430 embedded in the plurality of cover layers 410. The battery module 400 further includes a battery management circuit 440. Similar to the plurality of cover layers 110, 210, and 310, the plurality of cover layers 410 includes a first layer 416, a second layer 414, a third layer 412, and a fourth cover layer 432. The components of the battery module 400 are described in detail below.

[0082] The module 400 includes a stack of battery cells 402, such as lithium-ion cells. Each of the cells 402 in FIG. 4A includes an electrical terminal 404. In the embodiment of FIG. 4A, each cell 402 in the stack includes a vent 406. A plurality of cover layers 410 are included over the sides of the stack of lithium-ion cells that include the electrical terminals 404. A first layer 416 is shown having holes 417 for receiving the terminals 404. The first layer 416 also includes vent holes 407 that align with the vents 406 of the cells 402. A second layer 414 is also shown that includes holes 415 for receiving the terminals 404. A channel 418 is defined in the second layer 414. A third layer 412 is shown that does not include any holes.

[0083] Similar to the embodiment described above, in one embodiment, the multiple cover layers 410 are all made of the same material. In one embodiment, the multiple cover layers 410 include multiple materials for different layers. The layer adjacent to the channel 418 can be a thermally insulating layer to facilitate heating of adjacent components. In one embodiment, one or more of the multiple cover layers 410 include an aerogel layer. Other layers can include structural materials, such as polymers or metals such as stainless steel. An elastic material layer can be included in the multiple cover layers 410. In one embodiment, the multiple cover layers 410 can be connected by adhesive, stitching, taping, heat pressing, or the like. In one embodiment, the first layer 416 and the fourth layer 432 include aerogel, such as an aerogel plate, a fiber-reinforced aerogel blanket, other aerogel-containing layers, or combinations thereof. In one embodiment, the second layer 414 is an elastic layer, such as a foam, fiber, resin, polymer, other material that provides elasticity, or combinations thereof. In one embodiment, the third layer 412 is a rigid layer such as stainless steel, aluminum, mica, other rigid layers, and combinations thereof.

[0084] 4A includes a tube 420 that is a separate component contained within the plurality of cover layers 410. In other words, the tube 420 is not part of the plurality of cover layers 410. The tube 420 fits within a channel 418 in the second layer 414. In one embodiment, the tube 420 is formed from a fire-resistant or heat-resistant material. Embodiment materials include, but are not limited to, mica, metals, other fire-resistant or heat-resistant materials, and combinations thereof.

[0085] Further shown is an electrical connector 430 for coupling multiple terminals 404 together for further connection to device circuitry, an electric motor, etc. In the embodiment of FIG. 4A, a fourth layer 432 is included between second layer 414 and electrical connector 430.

[0086] In the embodiment of FIG. 4A, battery management circuitry 440 is located between one or more of the multiple cover layers 410. Functions of the battery management circuitry include, but are not limited to, temperature measurement and electrical feedback adjustments in response to temperature. Other electrical feedback adjustments may be made in response to other measured metrics, such as voltage, current, pressure sensing, moisture sensing, etc. In the embodiment of FIG. 4A, battery management circuitry 440 may communicate with other circuits wirelessly or via wires.

[0087] The battery management circuitry 440 may be embedded between the same layers as the electrical connector 430 shown in Figure 4A (e.g., between the third layer 412 and the fourth layer 432). Alternatively, the battery management circuitry 440 may be separated from the electrical connector 430 by one or more of the cover layers 410, as described below with respect to Figure 4B.

[0088] In FIG. 4B , the battery management circuit 440 is embedded in the multiple cover layers 410, separated from the electrical connector 430 by at least one of the layers within the multiple cover layers 410. The battery management circuit 440 includes wires 442 used for at least some communication with external circuitry. FIG. 4B also shows an optional separate circuit board 444 for holding the battery management circuit 440. The circuit board 444 may further include sensors for temperature, moisture, air pressure, etc. The battery management circuit 440, including sensors, cables, and other components, may be embedded in the multiple cover layers 410. The battery management circuit 440, including sensors, cables, and other components, is separated from the channel 418 and the tube 320 by one or more of the layers within the multiple cover layers 410.

[0089] E. Battery module housing including ventilation channels embedded in multiple cover layers 5A shows a partially assembled battery module 500 with the third layer 512 unassembled. Unlike FIGS. 4A-4B, the battery management circuitry 540 is wired instead of the wireless battery management circuitry 440 in the embodiment of FIGS. 4A and 4B. The wired battery management circuitry 540 includes a trace circuit 546. Additional electronic elements and connections (not shown) may be embedded in the multiple cover layers 510 along with the battery management circuitry 540.

[0090] 5A includes a stack of battery cells 502, multiple cover layers 510 over the battery cells 502, tubes 520, and electrical connectors 530 embedded in the multiple cover layers 510, similar to the battery modules 100, 200, 300, and 400 described above. Additionally, the battery module 500 further includes trace circuits 546 for wiring a battery management circuit 540 to the cell connectors 530 and terminals 504.

[0091] 4A-4B, the wired battery management circuit 540 may be electronically connected to the battery cell 502 by wires. Thus, the battery management circuit 540 may be powered by the battery cell 502. The wired battery management circuit 540 does not require an internal battery, as does the wireless battery management circuit 440, resulting in a smaller volume and longer usage time. The battery management circuit may connect to the battery cell 502 by a trace circuit 546 to monitor the cell's electrical characteristics or transmit information from other sensors (not shown), such as current, voltage, temperature, pressure, moisture, etc.

[0092] FIG. 5B illustrates a battery module 500 similar to the other battery modules described above, but further including an enclosure box 560 and an enclosure lid 562. In one embodiment, these enclosure components 560, 562 are separate from the other layers (e.g., the multiple cover layers 510) described within the battery module 500. In other words, the enclosure components 560 and 562 are not part of the multiple cover layers 510. In one embodiment, the stack of layers 510 on the battery module 500 includes a resilient, fire-resistant buffer material (e.g., the second layer 514). The multiple cover layers 510 function to occupy the space between the battery module 500 and the enclosure lid 562, thereby reducing vibration and noise while also providing a level of thermal insulation and thermal runaway protection. In one embodiment, the stack of layers 510 embeds the battery cell terminals, electrical connectors, battery management circuitry, and most of the tubing 520. The tube 520 directs the thermal runaway ejecta to the outside of the housing box 560 through a recess 564 on the side wall of the housing box 560 .

[0093] F. Ventilation channels embedded in multiple cover layers of the battery pack FIG. 6 illustrates one embodiment of a battery pack 600. The battery pack 600 includes multiple battery modules 601 that share one or more of multiple cover layers 610. The multiple cover layers 610 further embed a branch tube 620. Sharing one or more of multiple cover layers 610 between the modules 601 of the pack 600 saves pack space, improves pack efficiency, and makes assembly easier. The branch tube 620 offers the added benefit of design flexibility to further redirect any vent gases or flames away from critical components or undesired areas. The branch tube 620 also provides a single venting solution that consolidates a larger number of cells in multiple modules.

[0094] The battery pack 600 includes a plurality of battery modules similar to other battery modules described herein, with each module 601 including a stack of battery cells, such as lithium-ion cells 602. Each of the cells 602 includes an electrical terminal 604. In the embodiment of FIG. 6, each cell 402 in the stack includes a vent 606. Multiple cover layers 610 are included over the sides of the stack of lithium-ion cells 602 that include the electrical terminals 604. A first layer 616 is shown having holes 617 for receiving the terminals 604. A second layer 614 is also shown that also includes holes for receiving the terminals 604. Portions of the second layer 614 leave space for branch tubes 620. A third layer 612 is shown without any holes. An electrical connector 630 is included to couple several terminals 604 together. Battery pack 600 also includes a housing box 660 and a housing lid 662 similar to housing box 560 and housing lid 562 of the embodiment of FIGS. 5A-5B.

[0095] 1A-5B, the embodiment of FIG. 6 includes multiple battery modules 601 that share one or more of the multiple cover layers 610. In one embodiment, the battery pack 600 includes four battery modules 601. Each of the battery modules 601 has its own first layer 616 and second layer 614. In one embodiment, all of the battery modules 601 share the third layer 612 and the fourth layer 632.

[0096] The separate first and second layers 616, 614 of each battery module 601 provide space for the branch tubes 620 and allow for easier alignment with the terminals 604, vents 606, and tubes 620 during assembly of the battery pack 600. It also allows for individual replacement of the first and second layers 616, 614 of each battery module 601. Alternatively, shared third and fourth layers 612, 632 can be used because fewer components (e.g., electrical connectors 630 and tubes 620) need to be integrated into these two layers. The shared third and fourth layers 612, 632, when possible, provide easier installation options.

[0097] The embodiment of FIG. 6 further includes a branch tube 620 for receiving multiple modules within the battery pack 600. The branch tube 620 is different from the tubes 220, 320, 420, and 520 described above with respect to FIGS. 2A-5B. The branch tube 620 includes several sub-channels 621 that feed into a trunk 622. The sub-channels 621 are similar to the tubes 220, 320, 420, and 520 of FIGS. 2A-5B. In the illustrated embodiment, the trunk 622 is configured to redirect vent gas from the vent direction (e.g., Z direction) to a first channel direction (e.g., Y direction). In FIG. 6, the first channel direction is parallel to the length of the trunk 622, which is perpendicular to the vent portion 606. In one embodiment, branch tube 620 further includes a redirection end 624 that further redirects the vent gas from along trunk 622 (e.g., the Y direction) to a second channel direction (e.g., the negative Z direction). In the illustrated embodiment, the second channel direction is perpendicular to the first channel direction and downward (e.g., the negative Z direction), although the invention is not so limited.

[0098] In one embodiment, branch tube 620 comprises the same material as tubes 220, 320, 420, and 520 of Figures 2A-5B. In one embodiment, branch tube 620 comprises a material selected from, but not limited to, metal, mica, other flame-retardant and / or heat-resistant materials, and combinations thereof.

[0099] G. Alternative Ventilation Channel Configurations for Battery Modules Venting Towards the Side Walls of the Enclosure 7 shows one embodiment of a battery module 700. Multiple cover layers 710 are disposed between the battery cells 702 and the sidewalls of the housing 760, instead of between the battery cells and the housing lid as described in the embodiments of FIGS.

[0100] 1A-6, module 700 includes a stack of battery cells 702, such as lithium-ion cells. Each of the cells 702 in FIG. 7 includes an electrical terminal 704 and a vent 706. Multiple cover layers 710 are included on the sides of the stack of lithium-ion cells that include the electrical terminals 704 and the vent 706. Module 700 further includes a tube 720 embedded in the multiple cover layers 710. The cells 702, multiple cover layers 710, and tube 720 are housed in a module housing 760.

[0101] The multiple cover layers 710 include a first layer 716, a second layer 714, and a third layer 712. The first layer 716 is shown having a hole 717 for receiving the terminal 704. A vent hole 707 that aligns with the vent 706 of the cell 702 is also included in the first layer 716. A second layer 714 is further shown that aligns with the terminal 704 and also includes a hole for receiving the terminal 704. In the embodiment of FIG. 7, the second layer 714 includes multiple separate pieces disposed coplanarly within the multiple cover layers 710. The multiple (e.g., two) separate pieces of the second layer 714 define a channel 718 therebetween. The channel 718 spans the entire length of the second layer 714, separating the second layer 714 into two pieces. The third layer 712 is shown without any holes.

[0102] Similar to the embodiments of the cover layers 110, 210, 310, 410, 510, and 610 illustrated in FIGS. 1A-6, the cover layers 710 are all made of the same material in one embodiment. In another embodiment, the cover layers 710 include multiple materials for different layers. The layer adjacent to the channel 718 may be a thermally insulating layer to facilitate heating of adjacent components. In one embodiment, one or more of the cover layers 710 include an aerogel layer. Other layers (e.g., the third layer 712) may include a structural material, such as a polymer or a metal such as stainless steel. An elastic material layer (e.g., the second layer 714) may be included in the cover layers 710. The cover layers 710 may be connected by adhesive, stitching, taping, heat pressing, other connection methods, or a combination thereof. In one embodiment, the first layer 716, the second layer 714, and the third layer 712 are an aerogel layer, an elastic layer, and a rigid layer, respectively.

[0103] The embodiment of Figure 7 includes a tube 720 that is a separate component contained within the plurality of cover layers 710. In other words, the tube 720 is not part of the plurality of cover layers 710. The tube 720 fits within a channel 718 in the second layer 714. The tube 720 is similar to the tubes 220, 320, 420, 520, 621 in the embodiments of Figures 1A-6, except that the tube 720 has angled turns 722 on both ends of the tube rather than on one end.

[0104] In the embodiment of FIG. 7, tube 720 includes angled turns 722 at either or both ends of tube 720. Angled turns 722 direct thermal runaway ejecta in a desired direction, away from critical components of the equipment and / or users. The desired direction includes the bottom of the electric vehicle, which in the embodiment of FIG. 7 is the negative Z direction. In the embodiment of FIG. 7, housing 760 includes openings 764 through which angled turns 722 pass. Having two angled turns 722 further removes hot gases and flames outside of housing 760, compared to the single angled turn configuration in the embodiments of FIGS. 2A-6.

[0105] In one embodiment, tube 720 is formed from the same material as tubes 220, 320, 420, 520, and 621 in the embodiments of Figures 2A-6. In one embodiment, tube 720 comprises a material selected from a fire-resistant and / or heat-resistant material. In one embodiment, tube 720 comprises a material selected from aerogel material, aerogel blanket, mica, metal, other fire-resistant and / or heat-resistant materials, and combinations thereof.

[0106] 8A shows one embodiment of a battery module 800. The angled turn 822 in the battery module 800 is located in the middle portion of the tube 820. The location of the angled turn 822 in the middle reduces the travel length of the vent gas within the tube 820 compared to the travel length shown in FIG. 7, where the angled turn 722 is located at the end of the tube 720.

[0107] 1A-7, module 800 includes a stack of battery cells 802 and multiple cover layers 810 on the sides of the stack of battery cells 802. Module 800 also includes a tube 820, an enclosure box 860, and an enclosure lid 862.

[0108] In one embodiment, the stack of battery cells 802 may include lithium ion cells. Each stack of battery cells 802 may include electrical terminals 804 and a vent 806. The vent 806 is for releasing pressure and material from the cells that may arise during abuse conditions such as thermal runaway.

[0109] In one embodiment, the plurality of cover layers 810 includes a first layer 816, a second layer 814, and a third layer 812. The first layer 816 is shown having a hole 817 for receiving the terminal 804. A vent hole 807 that aligns with the vent 806 of the cell 802 is also included in the first layer 816. The second layer 814 is further shown also including a hole 815 for receiving the terminal 804. A plurality of channel holes 818 are included in the second layer 814. The third layer 812 is also shown including a channel hole 819 that aligns with the channel hole 818. A tube 820 passes through the second layer 814 and the third layer 812 through the channel holes 818 and 819.

[0110] In one embodiment, the plurality of cover layers 810 includes materials similar to those included in the plurality of cover layers 110, 210, 310, 410, 510, 610, and 710 in the embodiments of FIGS. 1A-7B. In one embodiment, the plurality of cover layers 810 includes multiple materials for different layers. Layers adjacent to the tube 820 and the channel holes 818 can be thermally insulating layers to facilitate heating of adjacent components. In one embodiment, one or more of the plurality of cover layers 810 includes an aerogel layer. Other layers can include structural materials, such as polymers or metals such as stainless steel. An elastic material layer can be included in the plurality of cover layers 810. The plurality of cover layers 810 can be connected by adhesives, stitching, taping, heat pressing, other connection methods, and combinations thereof. In one embodiment, the first layer 816, the second layer 814, and the third layer 812 are an aerogel layer, an elastic layer, and a rigid layer, respectively.

[0111] In the embodiment of Figures 8A-8B, multiple cover layers 810 embed a tube 820. The tube 820 includes one or more angled turns 822. The angled turns 822 are positioned in a mid-portion of the tube 820 to reduce the travel length of ventilation gases within the tube 820. The angled turns 822 are oriented in a desired direction away from critical components of the equipment and / or users. The desired direction includes the bottom of the electric vehicle, which is the negative Z direction in the embodiment of Figures 8A-8B.

[0112] In one embodiment, tube 820 comprises materials similar to those contained within tubes 220, 320, 420, 520, 621, and 720 in the embodiments of Figures 2A-7. In one embodiment, tube 820 is formed from a fire-resistant and / or heat-resistant material. In one embodiment, tube 820 comprises, but is not limited to, aerogel plates, mica, metal, other suitable materials, and combinations thereof.

[0113] 8A-8B, module 800 further includes an enclosure box 860 and an enclosure lid 862 that hold cell 802. Enclosure box 860 includes openings 864 in the sidewalls through which angled turns 822 pass through enclosure box 860. Openings 864 allow angled turns 822 to pass through the sidewalls of enclosure box 860, shortening the exit path of potential thermal runaway ejecta.

[0114] 8B shows an assembled battery module 800 with angled turns 822 protruding from the housing box 860 and angled downward. The angled turns 822 redirect the ejection outside the housing box 860, avoiding propagation or rupture of the battery module 800 within the housing box 860. The angled turns 822 redirect the ejection downward (negative Z direction), avoiding any injury or damage to vehicles or people adjacent above (e.g., in the Z direction) or next to (e.g., in the X or Y directions) the module 800.

[0115] 9 shows one embodiment of a battery module 900. The battery module 900 includes a tube 920 that directs the vent gas directly toward the bottom (e.g., in the negative Z direction) through a port 922. This differs from the embodiment shown in FIGS. 8A-8B, in which the tube 820 directs the vent gas to the side of the battery module and then directs it toward the bottom through angled turns 822.

[0116] Similar to modules 100-800 in the embodiments of FIGS. 1A-8B, module 900 includes a stack of battery cells 902, such as lithium-ion cells. Each of the cells 902 in FIG. 9 includes electrical terminals 904 and a vent 906. Battery module 900 includes multiple cover layers 910 on the sides of the stack of lithium-ion cells that include electrical terminals 904. The multiple cover layers 910 embed tubes 920. The battery module also includes a housing box 960 and a housing lid 962. In one embodiment, an additional elastic layer 963 is included between the cells 902 and the lid 962.

[0117] 1A-8, the plurality of cover layers 910 includes a first layer 916, a second layer 914, and a third layer 912. The first layer 916 includes a hole 917 for receiving the terminal 904. A vent hole 907 that aligns with the vent 906 of the cell 902 is also included in the first layer 916. Also shown is a second layer 914 that also includes a hole 915 for receiving the terminal 904. A third layer 912 is shown that does not include a channel hole.

[0118] In one embodiment, the plurality of cover layers 910 includes a material similar to the plurality of cover layers 110-810 in the embodiments of FIGS. 1A-8. In one embodiment, the plurality of cover layers 910 are all made of the same material. In one embodiment, the plurality of cover layers 910 includes multiple materials for different layers. Layers adjacent to the tube 920 (e.g., first layer 916 and second layer 914) can be thermally insulating layers to facilitate heating of adjacent components (e.g., tube 920). In one embodiment, one or more of the plurality of cover layers 910 includes an aerogel layer. Other layers can include structural materials, such as aerogel sheets, polymers, or metals such as stainless steel. An elastic material layer can be included in the plurality of cover layers 910. In one embodiment, the plurality of cover layers 910 can be connected by adhesive, stitching, taping, heat pressing, other suitable connection methods, and combinations thereof. In one embodiment, the first layer 916 is an aerogel layer, the second layer 914 is an elastic layer, and the third layer 912 is a rigid layer.

[0119] The embodiment of FIG. 9 includes a tube 920 that is a separate component contained within the multiple cover layers 910. In other words, the tube 920 is not part of the multiple cover layers 910. In the embodiment of FIG. 9, the tube 920 includes one or more ports 922. The ports 922 are oriented in a desired direction (e.g., toward the bottom of an electrical device, in a negative Z direction) away from critical components of the equipment and / or away from the user. The ports 922 direct the vent gases in a straight direction without turns. Compared to the angled turns 822 of FIGS. 8A-8B, thermal runaway ejecta are vented more efficiently through the straight ports 922 than through the angled turns 822, thereby improving safety.

[0120] In one embodiment, tube 920 comprises the same material as tubes 220, 320, 420, 520, 621, 720, and 820. In one embodiment, tube 920 is formed from a fire-resistant and / or heat-resistant material. In one embodiment, tube 920 comprises a material selected from aerogel, mica, metal, other suitable materials, and combinations thereof.

[0121] The module 900 further includes an enclosure box 960 and enclosure lid 962 for holding the cells 902, multiple cover layers 910, and tubes 920. In the embodiment of FIG. 9 , the enclosure box 960 includes an opening 964 through which the port 922 passes through the bottom wall of the enclosure box 960, thereby further removing hot gases and flames outside the enclosure box 960. The opening 964 facilitates straight port 922 and thermal runaway ejecta exiting the enclosure box 960. In one embodiment, the module 900 further includes an additional elastic layer 963. The additional elastic layer 963 provides cushioning to the battery cells 902 against mechanical damage in abuse conditions (e.g., impact, rupture, and thermal runaway). In one embodiment, the additional elastic layer 963 is an aerogel layer.

[0122] H. Top view, side view, and layer-by-layer diagram of multiple cover layers with embedded ventilation channels. 1A-9, except that the battery module 1000 includes battery cells arranged in multiple rows 1001 and multiple columns 1003. The battery module 1000 illustrates the flexibility of multiple cover layers 1010 and channels 1020 within a battery module with different cell arrangements.

[0123] The module 1000 includes a plurality of battery cells 1002, such as lithium-ion cells. Each of the cells 1002 in Figure 10A includes electrical terminals 1004 and a vent hole 1006. A plurality of cover layers 1010 are included on the sides of the plurality of cells that include the electrical terminals 1004. In the embodiment of Figures 10A-10B, the cells 1002 are arranged in a plurality of rows 1001 and columns 1003.

[0124] Similar to the multiple cover layers 110-910 in the embodiments of Figures 1A-9, the multiple cover layers 1010 include a first layer 1016, a second layer 1014, and a third layer 1016. The multiple cover layers 1010 may additionally include a structural material, for example, a polymer or a metal such as stainless steel. A resilient material layer may be included in the multiple cover layers 1010. The multiple cover layers 1010 may be connected by, for example, adhesive, stitching, taping, heat pressing, other suitable methods, and combinations thereof.

[0125] In one embodiment, the plurality of cover layers 1010 comprises the same material as the plurality of cover layers 110-910 in the embodiments of Figures 1A-9. In one embodiment, the plurality of cover layers 1010 are all the same material. In one embodiment, the plurality of cover layers 1010 comprise multiple materials for different layers. In one embodiment, one or more of the plurality of cover layers 1010 comprises an aerogel layer. In one embodiment, the first layer 1016 is an insulating layer (e.g., an aerogel layer), the second layer 1014 is an elastic layer, and the third layer is a rigid layer.

[0126] 10B shows a cross-sectional view of FIG. 10A along the centerline BB' of the first layer 1016, along the centerline CC' of the second layer 1014, and along the centerline DD' of the third layer 1012. The first layer 1016 includes holes 1007 arranged in rows and columns that align with the vent holes 1006 of the cells 1002. The second layer 1014 includes a plurality of channels 1020 that align with the rows 1001 of the cells 1002. Embodiments of suitable materials and configurations for the channels 1020 are included in other embodiments described herein. A third layer 1012 is also shown without any holes.

[0127] I. Method for forming a battery module having vent channels embedded in multiple cover layers 11 illustrates a flow diagram of an embodiment of a method 1100 for forming a battery module. In operation 1102, several lithium ion cells are stacked, each cell including an electrical terminal and a vent, the vent defining a vent direction. In operation 1104, a first layer is formed over the terminal surfaces of the several lithium ion cells, the electrical terminals passing through the first layer, and vent openings are included in the first layer and configured to allow vent gas to pass through the first layer. In operation 1106, channels are formed in communication with the vent openings, the channels configured to redirect vent gas from the vent direction to the channel direction.

[0128] J. Power battery system with battery module including ventilation channels embedded in multiple cover layers Battery modules such as those described above are used in several electronic devices. Figure 12 shows an exemplary electronic device 1200 including a battery module 1210. The battery module 1210 is coupled to functional electronics 1220 by circuitry 1212. In the illustrated embodiment, the battery module 1210 and circuitry 1212 are housed in a housing 1202. A charging port 1214 is shown coupled to the battery module 1210 to facilitate recharging the battery module 1210 when needed.

[0129] In one embodiment, functional electronics 1220 includes devices such as semiconductor devices with transistors and memory circuits, including, but not limited to, telephones, computers, display screens, navigation systems, and the like.

[0130] FIG. 13 illustrates another electronic system utilizing a battery module including a multi-layer thermal barrier as described above. An electric vehicle 1300 is illustrated in FIG. 13. The electric vehicle 1300 includes a chassis 1302 and wheels 1322. In the illustrated embodiment, each wheel 1322 is coupled to a drive motor 1320. A battery module 1310 is shown coupled to the drive motor 1320 by circuitry 1306. A charge port 1304 is shown coupled to the battery module 1310 to facilitate recharging the battery module 1310 when needed.

[0131] Embodiments of the electric vehicle 1300 include, but are not limited to, consumer vehicles such as cars, trucks, and the like. Commercial vehicles such as tractors and semi-trucks are also within the scope of the present invention. While a four-wheeled vehicle is shown, the present invention is not so limited. In one embodiment, two-wheeled vehicles such as motorcycles and scooters are also within the scope of the present invention.

[0132] Aspects In order to more fully describe the methods and apparatus disclosed herein, a non-limiting list of various aspects is provided herein.

[0133] Aspect 1 includes a battery module including: a stack of lithium ion cells, each cell including an electrical terminal; vents on each cell of the stack of lithium ion cells, each vent defining a vent direction; and at least one channel in communication with the vents of the stack of lithium ion cells, the channel configured to redirect vent gas from the vent direction to a channel direction.

[0134] Aspect 2 includes the electrical module of aspect 1, further including a plurality of cover layers positioned on sides of the stack of lithium-ion cells including the electrical terminals, the electrical terminals passing through one or more openings in the plurality of layers.

[0135] Aspect 3 includes the battery module of any one of Aspects 1-2, wherein one or more of the plurality of cover layers includes an aerogel.

[0136] A fourth aspect includes the battery module of any one of the first to third aspects, further including a battery management circuit located on one or more of the plurality of cover layers.

[0137] Aspect 5 includes the battery module of any one of Aspects 1-4, wherein the channel is defined by one or more spaces within the plurality of cover layers.

[0138] A sixth aspect of the present invention includes the battery module of any one of the first to fifth aspects, wherein the channel is filled with a sacrificial material.

[0139] Example 7 includes the battery module of any one of Examples 1-6, wherein the channel is a separate component contained within multiple layers.

[0140] Aspect 8 includes an electric vehicle. The electric vehicle includes a vehicle chassis, a plurality of wheels coupled to the vehicle chassis, the plurality of wheels driven by one or more electric motors, and a battery module connected to the one or more electric motors. The battery module includes a stack of lithium-ion cells, each cell including an electrical terminal, vents on each cell of the stack of lithium-ion cells, each vent defining a vent direction, and a channel in communication with the vents of the stack of lithium-ion cells, the channel configured to redirect vent gas from the vent direction to a channel direction.

[0141] Example 9 includes the electric vehicle of example 8, wherein the stack of lithium-ion cells is at least partially enclosed in a modular housing.

[0142] A tenth aspect includes the electric vehicle of any one of the eighth to nineth aspects, wherein the stack of lithium-ion cells is arranged in a single row of cells.

[0143] An eleventh embodiment includes the electric vehicle of any one of the eighth to tenth embodiments, wherein the stack of lithium ion cells is arranged in multiple rows of cells.

[0144] Aspect 12 includes the electric vehicle of any one of aspects 8-11, wherein the stack of lithium ion cells includes a plurality of cell banks, and the channel includes a trunk vent with a plurality of sub-vents.

[0145] A thirteenth aspect includes the electric vehicle of any one of aspects eight to twelfth, wherein the channels are oriented to vent to the sides of the electric vehicle.

[0146] Example 14 includes the electric vehicle of any one of Examples 8-13, wherein the channel is oriented to vent to an underside of the electric vehicle.

[0147] Aspect 15 includes a method of forming a battery module. The method includes stacking a number of lithium ion cells, each cell including an electrical terminal and a vent hole, the vent hole defining a vent direction, covering terminal surfaces of the number of lithium ion cells with a first layer, the electrical terminals passing through the first layer and vent openings included in the first layer configured to allow vent gas to pass through the first layer, and forming a channel in communication with the vent opening, the channel configured to redirect vent gas from the vent direction to a channel direction.

[0148] Example 16 includes the method of Example 15, wherein forming the channel includes disposing voids in multiple layers above the terminal surface.

[0149] Example 17 includes the method of any one of Examples 15-16, wherein forming the channel includes bonding a metal tube adjacent the vent opening.

[0150] Example 18 includes the method of any one of Examples 15-17, wherein covering the terminal surfaces of the some of the lithium-ion cells with the first layer includes covering with an aerogel layer. Conclusion, Terms, or other similar headings

[0151] The above description is intended to be illustrative, not limiting. In one aspect, the above-described aspects (or one or more aspects thereof) may be used in combination with each other. Other embodiments may be employed, such as by those of ordinary skill in the art who review the above description. The Abstract is provided to enable the reader to quickly grasp the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be construed as intending that any unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter lies in less than all features of a particular disclosed embodiment. Accordingly, it is contemplated that the following claims are incorporated into the Detailed Description herein, with each claim standing as a separate embodiment, and that such embodiments can be combined with each other in various combinations or variations. The scope of the invention should be determined with reference to the appended claims, along with the full range of equivalents to which such claims are entitled.

[0152] While the inventive subject matter has been generally described with reference to embodiments of particular aspects, various modifications and changes can be made to these embodiments without departing from the broader scope of the disclosed embodiments. Such embodiments of the inventive subject matter may be referred to herein, individually or collectively, by the term "invention" for convenience only, and this is not intended to intentionally limit the scope of this application to any single disclosure or inventive concept where multiple inventions are in fact disclosed.

[0153] The embodiments illustrated herein are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed. Other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of the present disclosure. Therefore, the detailed description is not to be construed in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled.

[0154] As used herein, the term "or" may be interpreted in either an inclusive or exclusive sense. Furthermore, multiple instances may be provided for resources, operations, or structures described herein as a single instance. Moreover, boundaries between various resources, operations, modules, engines, and data stores are somewhat arbitrary, and particular operations are illustrated in the context of specific exemplary configurations. Other allocations of functionality are contemplated and may be included within the scope of various embodiments of the present disclosure. In general, structures and functionality that are represented as separate resources in an aspect configuration may be implemented as a combined structure or resource. Similarly, structures and functionality that are represented as a single resource may be implemented as separate resources. These and other variations, modifications, additions, and improvements are within the scope of the embodiments of the present disclosure, as expressed by the appended claims. Accordingly, the specification and drawings should be regarded in an illustrative and not a restrictive sense.

[0155] The foregoing description, for purposes of illustration, has been set forth with reference to specific aspect embodiments. However, the foregoing illustrative description is not intended to be exhaustive or to limit possible aspect embodiments to the precise forms disclosed. Many modifications and variations are possible in light of the above teachings. The aspect embodiments have been chosen and described to best explain the principles involved and their practical application, thereby enabling those skilled in the art to best utilize various aspect embodiments, with their various modifications, as suited to the particular use intended.

[0156] It is also understood that terms such as "first" and "second" may be used herein to describe various elements, but these elements should not be limited by these terms. These terms are used only to distinguish one element from another. In one aspect, a first contact can be referred to as a second contact, and similarly, a second contact can be referred to as a first contact, without departing from the scope of the embodiments of this aspect. Although the first contact and the second contact are both contacts, they are not the same contact.

[0157] The terms used in the description of embodiments of aspects herein are for the purpose of describing particular embodiments of the aspect only and are not intended to be limiting. When used in the description of embodiments of this aspect and in the accompanying embodiments, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term "and / or," as used herein, is also understood to refer to and encompass any and all possible combinations of one or more of the associated listed items. It will be further understood that the terms "comprise" and / or "comprising," as used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0158] As used herein, the term "if" may be interpreted to mean "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [a stated condition or event] is detected" may be interpreted to mean "upon determining" or "in response to determining" or "upon detecting [the stated condition or event]" or "in response to detecting [the stated condition or event]," depending on the context.

Claims

1. A battery module, a stack of lithium ion cells, each cell including an electrical terminal; and a vent on each cell of the stack of lithium ion cells, each vent defining a vent direction; at least one channel in communication with the vent of the stack of lithium ion cells, the channel configured to redirect vent gas from the vent direction to a channel direction; The battery module.

2. 10. The electrical module of claim 1, further comprising a plurality of cover layers overlying sides of the stack of lithium-ion cells including the electrical terminals, the electrical terminals passing through one or more openings in the plurality of cover layers.

3. The battery module of claim 2 , wherein one or more of the plurality of cover layers comprises an aerogel.

4. The battery module of claim 2 further comprising a battery management circuit located on one or more of the plurality of cover layers.

5. The battery module of claim 4 , wherein the battery management circuitry is separated from the channel by at least one of the plurality of cover layers.

6. The battery module of claim 2 , wherein the channel is defined by one or more spaces within the plurality of cover layers.

7. The battery module of claim 2 , wherein the channel is embedded in an elastic layer of the plurality of cover layers.

8. The battery module of claim 5 , wherein the channels are filled with a sacrificial material.

9. The battery module of claim 1 , wherein the channel is a separate component contained within multiple layers.

10. An electric vehicle, A vehicle chassis; a plurality of wheels coupled to the vehicle chassis, the plurality of wheels being driven by one or more electric motors; a battery module connected to the one or more electric motors, a stack of lithium ion cells, each cell including an electrical terminal; and a vent on each cell of the stack of lithium ion cells, each vent defining a vent direction; a channel in communication with the vent of the stack of lithium ion cells, the channel configured to redirect vent gas from the vent direction toward the channel; the battery module, The electric vehicle.

11. The electric vehicle of claim 10 , wherein the stack of lithium-ion cells is at least partially enclosed in a modular housing.

12. 11. The electric vehicle of claim 10, wherein the stack of lithium-ion cells is arranged in a single row of cells.

13. The electric vehicle of claim 10 , wherein the stack of lithium-ion cells is arranged in multiple rows of cells.

14. The electric vehicle of claim 10 , wherein the stack of lithium-ion cells includes a plurality of cell banks and the channel includes a trunk vent with a plurality of sub-vents.

15. The electric vehicle of claim 10 , wherein the channels are oriented to vent to the sides of the electric vehicle.

16. The electric vehicle of claim 10 , wherein the channel is oriented to vent to the bottom of the electric vehicle.

17. 1. A method of forming a battery module, comprising: Stacking several lithium ion cells, each cell including an electrical terminal and a vent hole, the vent hole defining a direction of airflow; covering terminal surfaces of the number of lithium ion cells with a first layer, the electrical terminals passing through the first layer and vent openings included in the first layer configured to allow vent gas to pass through the first layer; forming a channel in communication with the vent opening, the channel configured to redirect vent gas from the vent direction to a channel direction; The method comprising:

18. The method of claim 17 , wherein forming the channels comprises disposing voids in multiple layers above the terminal surface.

19. The method of claim 17 , wherein forming the channel comprises bonding a metal tube adjacent the vent opening.

20. 18. The method of claim 17, wherein covering the terminal surfaces of the some of the lithium ion cells with the first layer comprises covering with an aerogel layer.

Images