Retainer for position securing of a thermal barrier within a battery

Abstract

A battery unit includes a unit housing enclosing a plurality of battery cells. To mitigate thermal risks and improve safety, the unit can include at least one thermal barrier arranged between the battery cells. The battery unit can also include a thermal barrier retainer arranged to protrude against a thermal barrier and secure the thermal barrier in place relative to the unit housing. Such a thermal barrier retainer can include sharp protrusions, gripping texture, or binding strips for engaging the thermal barrier.

Description

RETAINER FOR POSITION SECURING OF A THERMAL BARRIER WITHIN A BATTERYCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application S.N. 63 / 549,341, filed February 2, 2024, the contents of which is incorporated by reference herein in its entirety.BACKGROUND

[0002] Lithium-ion batteries (LIBs) can power portable electronic devices such as cell phones, tablets, laptops, power tools and other high-current devices, such as electric vehicles. LIBs provide benefits including a relatively high working voltage, low memory effects, and high energy density compared to traditional (e.g., lead acid) batteries. LIBs generally include electrochemical cells that store and release energy through the movement of lithium ions between the anode (negative electrode) and cathode (positive electrode). The electrolyte is a conductive solution that allows the lithium ions to move between the two electrodes during charging and discharging. The anode is typically made of graphite, while the cathode can be made of a variety of materials such as lithium cobalt oxide or lithium iron phosphate.BRIEF DESCRIPTION OF THE DRAWINGS

[0003] In the drawings, which are not necessarily drawn to scale, like numerals can describe similar components in different views. Like numerals having different letter suffixes can represent different instances of similar components. The drawings illustrate generally, by way of aspect, but not by way of limitation, various embodiments discussed in the present document.

[0004] FIG. 1A shows an aspect of a battery unit.

[0005] FIG. IB shows a configuration of a battery unit that includes an optional heat sink, or cooling plate, located on a bottom of the unit, and in thermal communication with the battery cells.

[0006] FIG. 2 is an exploded view of an aspect of a battery unit.

[0007] FIG. 3A is a side view depicting an aspect of a battery unit.

[0008] FIG. 3B is a side view depicting an aspect of a battery unit.

[0009] FIG. 3C is a side view depicting an aspect of a battery unit.

[0010] FIG. 3D is a side view of an aspect of a battery unit.

[0011] FIG. 3E is a chart that corresponds with FIG. 3D and shows respective tolerance distributions yxof successive thermal barriers.

[0012] FIG. 4A depicts an aspect of a barrier retainer for use in a battery unit.

[0013] FIG. 4B depicts an aspect of a barrier retainer for use in a battery unit.

[0014] FIG. 4C depicts an aspect of a barrier retainer for use in a battery unit.

[0015] FIG. 5A is an exploded perspective view depicting an aspect of an interface between an elongated binding strip of a barrier retainer and a corresponding thermal barrier.

[0016] FIG. 5B is an exploded perspective view of the enlarged portion of FIG. 5 A in the dashed box.

[0017] FIG. 5C is an assembled perspective view depicting an aspect of an interface between an elongated binding strip of a barrier retainer and a corresponding thermal barrier.

[0018] FIG. 5D is an assembled perspective view of the enlarged portion of FIG. 5C in the dashed box.

[0019] FIG. 5E is an exploded perspective view depicting an aspect of an interface between an elongated binding strip of a barrier retainer and a corresponding thermal barrier.

[0020] FIG. 5F is an exploded perspective view of the enlarged portion of FIG. 5E in the dashed box.

[0021] FIG. 5G is an exploded perspective view depicting an aspect of an interface between an elongated binding strip of a barrier retainer and a corresponding thermal barrier.

[0022] FIG. 5H is an exploded perspective view of the enlarged portion of FIG. 5G in the dashed box.

[0023] FIG. 6A depicts another aspect of an elongated binding strip for engaging a corresponding thermal barrier.

[0024] FIG. 6B depicts the elongated binding strip of FIG. 6A in a different view angle.

[0025] FIG. 7A depicts an aspect of a battery unit including elongated binding strips formed into one or more inner surfaces of the unit housing.

[0026] FIG. 7B depicts an aspect of a barrier retainer having a textured gripping feature formed across a majority of the surface of the retainer.

[0027] FIG. 7C depicts another aspect of a barrier retainer having a textured gripping feature formed across a majority of the surface of the retainer.

[0028] FIG. 7D depicts the barrier retainer of FIG. 7C in a different view angle.

[0029] FIG. 8A depicts an aspect of a barrier retainer having textured gripping features.

[0030] FIG. 8B depicts an aspect of another barrier retainer having textured gripping features.

[0031] FIG. 9A depicts an aspect of an arrangement of battery cells, thermal barriers, and a barrier retainer.

[0032] FIG. 9B depicts an aspect of the thermal barrier, including an expanding edge.

[0033] FIG. 9C depicts an aspect of the thermal barrier, including an expanding edge.

[0034] FIG. 10 schematically illustrates an aspect of an electronic device that includes a battery unit.

[0035] FIG. 11 schematically illustrates another electronic system that utilizes battery units that include thermal management systems (e.g., thermal barrier, barrier retainer, etc.) as described herein.

[0036] FIG. 12 is a flowchart illustrating steps for constructing an aspect of a battery unit.DETAILED DESCRIPTION

[0037] Lithium Ion Batteries (LIBs) can be susceptible to failure, e.g., where a battery is subjected to an irregular condition. In one aspect, where a rechargeable battery is overcharged (being charged beyond a specified voltage), over-discharged, operated at or exposed to high temperature or high pressure, or is subjected to physical shock, the battery can fail prematurely. A failure of a LIB cell can include short circuiting, thermal runaway, gas generation, or swelling of the cell. In one aspect, a cascading and mutual thermal or gas-induced breakdown of adjoining or adjacent lithium-ion batteries can collectively fail or cause thermal destruction of one or more and surrounding cells. This can occur after only one cell has failed or through a combination of factors that cause the cells to collectively fail. In one aspect, this failure is commonly referred to as a "thermal event" (i.e., thermal runaway event). Thermal barriers (also referred to herein as barriers) are often used between battery cells to prevent heat propagation between the cells during a thermal event. To effectively block heat and thermal runaway ejecta from traveling to adjacent battery cells, the thermal barriers need to stay in place in the battery housing during thermal runaway. The present disclosure provides methods and configurations to secure the thermal barriers to the battery housing, e.g., via a thermal barrier retainer.

[0038] The thermal barrier retainer is also referred to herein as barrier retainer or retainer.

[0039] To accomplish these benefits, a thermal barrier retainer may include protrusions that engage and / or perforate a minor (e.g., edge or peripheral) surface of one or more thermal barriers, thereby securing the position(s) of the thermal barrier(s) in the battery housing. The protrusions of the thermal barrier retainer can be configured such that they can conveniently engage even thin thermal barriers (e.g., having a thickness less than 3 mm, less than 2 mm, less than 1 mm) while still positioning the thermal barriers at the desired location within a battery pack. This benefit improves the performance and manufacturability of battery packs using even very thin (e.g., less than 2 mm) thermal barriers.

[0040] In aspects, the protrusions of the thermal barrier retainer may comprise elongated binding stripes. The elongated binding stripes may further comprise at least one row of teeth. Alternatively, the protrusions may be distributed throughout the surface of the barrier retainer. The protrusions may include various sizes and shapes, such as knurling, pyramid, cone, threading, diamond plate texture, checker plate texture, or hemispherical surface texture.

[0041] The thermal barriers may comprise at least one of insulation materials, thermal conductor materials, resilient materials, and / or combinations thereof, as described in detail below. The thermal barriers can be used in battery units to prevent heat and thermal runaway ejecta from traveling to adjacent battery cells during thermal runaway. The devices and methods described herein can be used in any of several types of multiple battery cell arrangements, which may be termed battery unit, battery module, battery packs, battery systems, etc.

[0042] Insulation materials as described below can be used in the thermal barriers as a single heat- resistant layer, or in combination with other layers that provide additional function to a multilayer configuration, such as mechanical strength, compressibility, heat dissipation / conduction, and / or resistance to damage or erosion by heat and / or battery ejecta. Insulation layers described herein are responsible for reliably containing and controlling heat flow from a heat-generating battery cell to adjacent battery cells.

[0043] In many aspects of the present disclosure, the insulation layer functions as a flame / fire deflector layer either by itself or in combination with other materials that enhance performance of containing and controlling heat flow. In one aspect, the insulation layer may itself be resistant to flame and / or hot gases and further include entrained particulate materials (e.g., heat capacitive materials, intumescent materials, heat reflectors) that modify or enhance heat containment and control.Aerogels

[0044] One aspect of a highly effective insulation layer includes an aerogel. Aerogels describe a class of material based upon their structure, namely low density, open cell structures, large surface areas (often 900 m2 / g or higher) and subnanometer scale pore sizes. The pores may be filled with gases, such as air. Aerogels can be distinguished from other porous materials by their physical and structural properties. Although an aerogel material is an exemplary insulation material, the aspects set forth herein are not so limited. Other thermal insulation material layers may also be used in aspects of the present disclosure.

[0045] Selected aspects of aerogel formation and properties are described. In several aspects, a precursor material is gelled to form a network of pores that are filled with solvent. The solvent is then extracted, leaving behind a porous matrix. A variety of different aerogel compositions are known, and they may be inorganic, organic or inorganic / organic hybrids. Inorganic aerogels are generally based upon 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.

[0046] Inorganic aerogels may be formed from metal oxide or metal alkoxide materials. The metal oxide or metal alkoxide materials may be based on oxides or alkoxides of any metal that can form oxides. 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 (such as tetraethoxylsilane), or via 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, tetraethoxylsilane (TEOS), partially hydrolyzed TEOS, condensed polymers of TEOS, tetramethoxyl silane (EMOS), partially hydrolyzed TMOS, condensed polymers of TMOS, tetra-n-propoxysilane, partially hydrolyzed and / or condensed polymers of tetra-n-propoxysilane, polyethylsilicates, partially hydrolyzed polyethysilicates, monomeric alkylalkoxy silanes, bis-trialkoxy alkyl or aryl silanes, polyhedral silsesquioxanes, or combinations thereof.

[0047] In certain embodiments of the present disclosure, pre-hydrolyzed TEOS, such as Silbond H-5 (SBH5, Silbond Corp), which is hydrolyzed with a water / silica ratio of about 1.9-2, may beused as commercially available or may be further hydrolyzed prior to incorporation into the gelling process. Partially hydrolyzed TEOS or TMOS, such as polyethysilicate (Silbond 40) or polymethylsilicate may also be used as commercially available or may be further hydrolyzed prior to incorporation into the gelling process.

[0048] Inorganic aerogels can also include gel precursors comprising at least one hydrophobic group, such as alkyl metal alkoxides, cycloalkyl metal alkoxides, and aryl metal alkoxides, which can impart or improve certain properties in the gel, such as stability and hydrophobicity. Inorganic silica aerogels can specifically include hydrophobic precursors, such as alkylsilanes or arylsilanes. Hydrophobic gel precursors may be used as primary precursor materials to form the framework of a gel material. However, hydrophobic gel precursors are more commonly used as co-precursors in combination with simple metal alkoxides in the formation of amalgam aerogels. Hydrophobic inorganic precursor materials for silica based aerogel synthesis include, but are not limited to, trimethyl methoxysilane (TMS), dimethyl dimethoxysilane (DMS), methyl trimethoxysilane (MTMS), trimethyl ethoxysilane, dimethyl diethoxysilane (DMDS), methyl triethoxysilane (MTES), ethyl triethoxysilane (ETES), diethyl diethoxysilane, dimethyl diethoxysilane (DMDES), ethyl triethoxysilane, propyl trimethoxysilane, propyl triethoxysilane, phenyl trimethoxy silane, phenyl triethoxysilane (PhTES), hexamethyldisilazane and hexaethyldisilazane, and the like. Any derivatives of any of the above precursors may be used; and specifically, certain polymeric or other chemical groups may be added or cross-linked to one or more of the above precursors.

[0049] Organic aerogels are generally formed from carbon-based polymeric precursors. Such polymeric materials include, but are not limited to, resorcinol formaldehydes (RF), polyimide, polyacrylate, polymethyl methacrylate, acrylate oligomers, polyoxyalkylene, polyurethane, polyphenol, polybutadiane, trialkoxysilyl-terminated polydimethylsiloxane, polystyrene, polyacrylonitrile, polyfurfural, melamine-formaldehyde, cresol formaldehyde, phenol-furfural, polyether, polyol, polyisocyanate, polyhydroxybenze, polyvinyl alcohol dialdehyde, polycyanurates, polyacrylamides, various epoxies, agar, agarose, chitosan, and combinations thereof. As one aspect, organic RF aerogels are typically made from the sol-gel polymerization of resorcinol or melamine with formaldehyde under alkaline conditions.

[0050] Organic / inorganic hybrid aerogels are mainly comprised of organically modified silica (“ormosil”) aerogels. These ormosil materials include organic components that are covalently bonded to a silica network. Ormosils are typically formed through the hydrolysis and condensationof organically modified silanes, R— Si(OX)s, with traditional alkoxide precursors, Y(0X)4. In these formulas, X may represent, in one aspect, CH3, C2H5, C3H7, C4H9; Y may represent, in one aspect, Si, Ti, Zr, or Al; and R may be any organic fragment such as methyl, ethyl, propyl, butyl, isopropyl, methacrylate, acrylate, vinyl, epoxide, and the like. The organic components in ormosil aerogel may also be dispersed throughout or chemically bonded to the silica network.

[0051] Aerogels can be formed from flexible gel precursors. Various flexible layers, including flexible fiber-reinforced aerogels, can be readily combined and shaped to give pre-forms that when mechanically compressed along one or more axes, give compressively strong bodies along any of those axes.

[0052] One method of aerogel formation includes batch casting. Batch casting includes catalyzing one entire volume of sol to induce gelation simultaneously throughout that volume. Gel-forming techniques include adjusting the pH and / or temperature of a dilute metal oxide sol to a point where gelation occurs. Suitable materials for forming inorganic aerogels include oxides of most of the metals that can form oxides, such as silicon, aluminum, titanium, zirconium, hafnium, yttrium, vanadium, and the like. Particularly preferred are gels formed primarily from alcohol solutions of hydrolyzed silicate esters due to their ready availability and low cost (alcogel). Organic aerogels can also be made from melamine formaldehydes, resorcinol formaldehydes, and the like.

[0053] In one aspect, aerogel materials may be monolithic, or continuous throughout a structure or layer. In other aspects, an aerogel material may include a composite aerogel material with aerogel particles that are mixed with a binder or carrier. Other additives may be included in a composite aerogel material, including, but not limited to, surfactants that aid in dispersion of aerogel particles within a binder or carrier. A composite aerogel slurry may be applied to a supporting plate, such as a mesh, felt, web, etc. and then dried to form a composite aerogel structure.Reinforcement

[0054] As noted above, an aerogel may be organic, inorganic, or a mixture thereof. In some aspects, the aerogel includes a silica-based aerogel. One or more layers in a thermal barrier may include a reinforcement material. The reinforcing material may be any material that provides resilience, conformability, or structural stability to the aerogel material. Aspects of reinforcing materials include, but are not limited to, open-cell macroporous framework reinforcementmaterials, closed-cell macroporous framework reinforcement materials, open-cell membranes, honeycomb reinforcement materials, polymeric reinforcement materials, and fiber reinforcement materials such as discrete fibers, woven materials, non-woven materials, needled non-wovens, battings, webs, mats, and felts.

[0055] The reinforcement material can be selected from organic polymer-based fibers, inorganic fibers, carbon-based fibers, or a combination thereof. The inorganic fibers may be selected from glass fibers, rock fibers, metal fibers, boron fibers, ceramic fibers, basalt fibers, other inorganic fibers, or combinations thereof. The organic polymer-based fibers may be selected from polyester polypropylene fibers, acrylic fibers, polyvinyl chloride fibers, aramid fibers, spandex fibers, nylon fibers, pre-oxidized fibers, pre-oxidized polyacrylonitrile (OP AN) fibers, other organic fibers, or combinations thereof. In some aspects, the reinforcement material can include a plurality of layers of material.Thermal Conduction

[0056] In addition to thermal insulating layers, the thermal barrier may further include thermal conductive layers. Thermally conductive layers in combination with thermal insulating layers are effective at channeling unwanted heat to a desired external location, such as external heat dissipating fins, a heat dissipating housing, or another external structure to dissipate unwanted heat to outside ambient air. In one aspect, a thermally conductive layer or layers helps to dissipate heat away from a localized heat load within a battery unit or pack. Aspects of high thermal conductivity materials include carbon fiber, carbon nanotubes, graphene, graphite, pyrolytic graphite sheets, silicon carbide, metals or metal alloys (including, but not limited to, copper, stainless steel, aluminum, and the like), as well as combinations thereof.

[0057] To aid in the distribution and removal of heat, in at least one embodiment, the thermally conductive layer is coupled to a heat sink. It will be appreciated that there are a variety of heat sink types and configurations, as well as different techniques for coupling the heat sink to the thermally conductive layer, and that the present disclosure is not limited to the use of any one type of heat sink and / or coupling technique. In one aspect, at least one thermally conductive layer of the multilayer materials disclosed herein can be in thermal communication with an element of a cooling system of a battery unit or pack, such as a cooling plate or cooling channel of the cooling system. For another aspect, at least one thermally conductive layer can be in thermalcommunication with other elements of the battery pack, battery unit, or battery system that can function as a heat sink, such as the walls of the pack, unit, or system, or with other elements of the multilayer materials disposed between battery cells. Thermal communication between the thermally conductive layer and heat sink elements within the battery system can allow for removal of excess heat from the battery cell or battery cells adjacent to the multilayer material to the heat sink, thereby reducing the effect, severity, or propagation of a thermal event that may generate excess heat. In addition to removal of heat, a thermally conductive layer can spread, or dissipate, heat from a region of high heat concentration to a larger region of lower heat concentration.Resilient Materials

[0058] In addition to thermal insulating layers and thermal conductive layers, the thermal barrier may further comprise one or more resilient material layers. In one aspect, a resilient layer absorbs any volume expansion during the regular operation of one or more battery cells. In one aspect during a charge, the battery cells may expand, and during a discharge, the battery cells may shrink. In one aspect, the resilient layer may also absorb permanent volume expansion caused by any battery cell degradation and / or thermal runaway. Resilient material layers may include, but are not limited to, foam, fiber, fabric, sponge, spring structures, rubber, polymer, etc.Thermal Barrier Retainer

[0059] FIG. 1A shows one aspect of a battery unit 100. The unit 100 includes a stack of battery cells 102 and a thermal barrier 110.

[0060] In one aspect, the stack of battery cells 102 includes prismatic battery cells or pouch battery cells, although the disclosure is not so limited. In one aspect, the stack of lithium-ion battery cells 102 includes lithium nickel manganese cobalt (NMC) oxide battery cells, although the disclosure is not so limited. The battery cells 102 in FIG. 1 A each include electrical terminals 104. Although battery cells 102 with terminals 104 on a top surface (in X-Y plane) of the battery cells 102 are shown in the aspect of FIG. 1A, other configurations are also within the scope of the disclosure, including, but not limited to, other aspects where the terminals 104 are disposed on a side (in X-Z plane or in Y-Z plane) or bottom surface (in X-Y plane opposite to the top surface) of the battery cells 102.

[0061] The battery unit 100 includes one (shown) or more thermal barriers 110, which as noted above, may mitigate heat and ejecta propagation between battery cells 102 during thermal runaway conditions. The thermal barrier 110 comprises one or more layers selected from an insulator layer, a dielectric layer, and a conductive layer, all of which have been described above in detail. In some aspects, the thermal barrier 110 may further include an encapsulation layer that surrounds one or more of the constituent layers of the thermal barrier 110 (i.e., encapsulates one or more of the insulation layer, the dielectric layer, and the conductive layer). The encapsulation layer may reduce dust, improve the cosmetic uniformity of the outside of the thermal barrier 110, and / or provide a surface on which to print or affix identifying symbols useful for manufacturing (e.g., lot number, producer, production location, fabrication machine traceability codes). In some aspects, the encapsulation layer may be a polymer layer (e.g., polyethylene terephthalate (PET), polyethylene (PE)).

[0062] The present disclosure refers to the “lateral footprint” of various components, including the battery cells 102 and the thermal barrier 110. The lateral footprint of a component refers to the area of a major surface of the component as defined by the perimeter of the component. As shown in FIG. 1A, major surfaces of the battery cells 102 and the thermal barrier 110 are those surfaces in the Y-Z plane (referring to the reference axis in FIG. 1A). For clarity and convenience of explanation, the term battery cell (equivalently “battery” or “cell”) lateral footprint (“footprint”) refers to a major surface of the battery cell in the Y-Z plane in FIG. 1A. Analogously, the thermal barrier lateral footprint (“footprint”) refers to a major surface of the thermal barrier 110 in the Y- Z plane in FIG. 1A. In some aspects described below, a thermal barrier may be fabricated from multiple laminated layers, each of which may have its corresponding lateral footprint (i.e., an insulator lateral footprint, a dielectric reinforcing layer lateral footprint). For clarity, “minor surfaces,” (equivalently referred to as “edges” or “peripheral surfaces” are those surfaces that are orthogonal to the major surfaces and, using the reference coordinate axes in FIG. 1A, correspond to the surfaces in the X-Y plane or the X-Z plane.

[0063] FIG. IB shows a cross section of a configuration of a battery unit 150 that includes battery cells 152, one or more thermal barriers 160, and an optional heat sink 154 or cooling plate.

[0064] In FIG. IB, the one or more of the battery cells 152 are shown separated by one or more thermal barriers 160. Although in FIG. IB, the battery unit 150 comprises one thermal barrier 160 between every four or five battery cells 152, the present disclosure is not so limited. In otheraspects, the battery unit 150 comprises one thermal barrier 160 between each battery cell 152, each two battery cells 152, or each suitable numbers of battery cells 152. Side, bottom or top surfaces of the battery unit 150 may also include thermal barriers 160. Aspects of the thermal barriers 110, 160 are described in more detail in the discussion of the Figures below.

[0065] Also in FIG. IB, the optional heat sink 154 is in thermal communication with the battery cells 152. In this aspect, the optional heat sink 154 is located on a bottom of the unit 150 to establish thermal communication with the individual battery cells 152. This is merely illustrative. It will be appreciated that one or more heat sinks 154 can be placed in various positions to establish thermal communication with one or more of the battery cells 152 depending on the configuration and design of the battery unit 150.

[0066] In FIG. 1A and FIG. IB, the thermal barriers 110, 160 are depicted with a lateral footprint that matches a lateral footprint of the battery cells 102, 152. Put another way, a lateral surface area of the thermal barriers 110, 160 is similar or identical to the lateral surface area of the battery cells 102, 152 themselves. The thermal barriers 110, 160 do not extend beyond lateral dimensions of the battery cells 102, 152. The term “footprint” can be used to illustrate how different battery cells not illustrated in the aspect of FIG. 1A and FIG. IB may include different lateral geometries apart from rectangular or square. In one aspect, pouch battery cells may be generally rectangular, but may have a less defined outline. A less defined outline of a pouch battery cell will still define a lateral footprint, although the footprint may not be entirely defined by a length times a width, as is the case with a rectangular battery cell. For convenience of explanation, the lateral footprint of a pouch battery cell may be defined by the length and the width of the electrodes of the pouch battery cell (consistent with the axes-based definition above). Alternatively, the lateral footprint of a pouch cell may be defined by the length and the width of the outer periphery of a pouch battery cell, and consistent with the axes-based definition above.

[0067] FIG. 2 is an exploded view of an aspect of a battery unit 200. The battery unit 200 is substantially similar to the battery unit 100 and battery unit 150, respectively described above with reference to FIG. 1A and FIG. IB. The components, structures, configurations, functions, etc. of the battery unit 200 can therefore be the same as or substantially similar to that described in detail with respect to the battery unit 100 and the battery unit 150.

[0068] The battery unit 200 comprises a unit housing 264, a plurality of battery cells 252 arranged within the unit housing 264, a heat sink 254, and one or more thermal barriers 260 between batterycells 252, and a barrier retainer 266. The battery cells 252, heat sink 254, and the constituent one or more layers of the thermal barriers 260 have been described above in detail. Each of the preceding descriptions is applicable to the aspects illustrated in FIG. 2 and are omitted in this example for brevity and convenience of explanation.

[0069] In an aspect, the one or more thermal barriers 260 (each of which may include one or more of the insulative, conductive, resilient, and / or encapsulating layers described above) may be disposed between battery cells 252 and / or between one battery cell 252 and the unit housing 264.

[0070] In an aspect, the battery unit 200 can also comprise a heat sink 254 arranged within the housing 264, such as along an inner surface of the unit housing 264. The battery unit 200 can also include a barrier retainer 266 arranged to engage with the one or more thermal barriers 260 to secure the positions of the barrier 260 relative to the unit housing 264. In an aspect, the unit housing 264 can include a removable or otherwise openable lid 265.

[0071] As an added measure that may improve the performance of a thermal barrier 260 by decreasing a likelihood of one cell 252 in thermal runaway from initiating runaway in a proximate cell 252 (or alternatively increasing the amount of time it takes for thermal runaway to spread from one cell 252 to another), thermal barriers 260 may have larger footprints than the cells 252 themselves. This configuration is illustrated in FIG. 2. With a footprint larger than that of an adjacent battery cell 252, a thermal barrier 260 may prevent heat and ejecta from one cell 252 from traveling to other cells 252, thereby preventing heat transfer and cell damage that could otherwise trigger thermal runaway in adjacent cell(s) 252.

[0072] As depicted in FIG. 2, an individual barrier of the one or more thermal barriers 260 can extend a distance J beyond the footprint of battery cell 252 in the housing 264. This portion of the thermal barrier 260 extending beyond the battery cell 252 footprint (a distance d multiplied by the y-dimension of the thermal barrier 260) may be termed an “extension” or an “extension portion” for convenience. In this configuration, the “footprint” (e.g., a lateral surface area) of an individual thermal barrier 260 can be larger than the footprint (e.g., lateral surface area) of an adjacent battery cell 252.

[0073] The extensions of the corresponding one or more barriers 260 can define a plurality of voids 261 in cooperation with other elements of the structures shown in FIG. 2. Generally, the plurality of voids 261 provides space to contain heat and thermal runaway ejecta during thermal runaway. The thermal barriers 260 prevent heat or thermal runaway ejecta from spreading to anadjacent battery cell 252. Each of the voids 261 is defined by a respective battery cell 252, two barriers 260 that are directly adjacent to the respective battery cell 252, and the barrier retainer 266. The voids 261 at the end of the battery unit 200 are each defined by the respective battery cell 252 that is adjacent to the end, the barrier 260 that is adjacent to the respective battery cell 252, the barrier retainer 266, and a sidewall of the unit housing 264 that defines the end.

[0074] To further improve the performance of the thermal barriers 260, structures are added to physically maintain the relative positions of the extension portions of the thermal barriers 260 even when experiencing pressure from thermal runaway heat and ejecta. In order to stabilize the extension portions, maintain the voids 261, and contain the thermal runaway heat and ejecta, one aspect includes adding structures that enable the barrier retainer 266 to engage with the thermal barriers 260, thereby keeping the relative positions of the thermal barriers 260 in the unit housing 264 regardless of the pressure and / or adversity of conditions.

[0075] In one aspect, the barrier retainer 266 comprises protrusions, such as male features 267, to better engage with the thermal barriers 260. The male features 267 may be in different shapes. In one aspect, the male features 267 of the barrier retainer 266 may be a plurality of elongated binding strips as shown in FIG. 2. The elongated binding strips are also shown in FIG. 3 at reference numeral 268. In aspects, the elongated binding strips 268 may be each sized, shaped, and arranged on the barrier retainer 266 to extend along and engage with a peripheral surface of a corresponding individual thermal barrier 260.

[0076] FIG. 3A, FIG. 3B, and FIG. 3C are side views depicting several aspects of a battery unit 300A, 300B, 300C. FIG. 3A, FIG. 3B, and FIG. 3C depict one aspect of solving a tolerance issue when engaging the thermal barriers 260 with the barrier retainer 266a, 266b, and 266c (collectively referred to as barrier retainer 266). The battery units 300 A, 300B, and 300C are each substantially similar to the battery unit 100, battery unit 150, and battery unit 200 respectively described above with reference to FIG. 1A, FIG. IB, and FIG. 2. The components, structures, configurations, functions, etc. of each of the battery units 300A, 300B, and 300C can therefore be the same as or substantially similar to that described in detail with respect to the battery unit 100, the battery unit 150, and the battery unit 200.

[0077] It can be challenging to keep the thermal barrier 260 in place in the unit housing (e.g., the unit housing 264 in FIG. 2, not shown in FIG. 3 A through FIG. 3C). One aspect of maintaining the relative positions of the thermal barriers 260 in the unit housing 264 is to engage the thermalbarriers 260 with a barrier retainer 266, as described above in the context of FIG. 2. In one aspect, as depicted from the side view in FIG. 3A, a barrier retainer 266a includes one or more female features 367a each corresponding with an individual thermal barrier 260. Here, the features 367a are longitudinal grooves sized and shaped along the barrier retainer 266a to receive an individual thermal barrier 260 therein and thereby secure the position of the thermal barrier 260. One challenge with this approach arises as a result of normal variance of thicknesses of battery cells 252 and thermal barriers 260 during manufacturing. In one aspect, relatively small variances yx(e g., yxis less than a thickness of the thermal barrier 260) in thickness of components making up the battery unit 300A can compound to create an offset or misalignment between the thermal barriers 260 and their corresponding female features 367a. This can result in a relatively small acceptable tolerance in manufacturing of the barrier retainer 266a, the battery cells 252, and the thermal barriers 260. Such a tolerance can be unfeasible to achieve in certain circumstances, such as in fabricating components for batteries with target parameters at the millimeter or micrometer level.

[0078] The manufacturing challenges posed by even small variations in dimensions are illustrated in FIGS. 3D and 3E. In one aspect, FIG. 3D is another side view of an aspect of a battery unit, and FIG. 3E is a chart that corresponds with FIG. 3D and shows respective tolerance distributions f of successive thermal barriers. As shown in FIG. 3E, as more battery cells 252 and thermal barriers 260 are arranged consecutively (e.g., from a sidewall to the center of the unit housing 264 as depicted in the chart), a tolerance yxincreases. In one aspect, the thermal barriers 260 have tolerances yi, y2, and y3 at distances xi, X2, and X3 from the sidewall of the unit housing 264, respectively. In one aspect, the tolerances yi, y2, and ys gradually increase as the distances xi, X2, and X3 gradually increase. One aspect of the present disclosure describes a method of securing the relative position of the thermal barriers 260 in the unit housing 264, while increasing an acceptable tolerance in manufacturing of components of the battery unit. In some instances, increasing an acceptable tolerance in manufacturing allows thinner thermal barriers 260 to be used for cost and space efficiency purposes.

[0079] As shown in FIG. 3B, an aspect of a barrier retainer 266b comprises a plurality of male features 367b. An individual male feature 367b is arranged to engage, bind, or protrude against a corresponding thermal barrier 260. In this case, the male feature 367b enables a greater tolerance zxcompared to the tolerance yxof the female feature 367a illustrated in FIG. 3A. The tolerance zxequals the thickness of the thermal barrier 260. In other words, the thermal barrier 260 is able to engage with the barrier retainer 266b as long as the male feature 367b engages with the surface defining the thickness of the thermal barrier 260.

[0080] As shown in FIG. 3C, an aspect of a barrier retainer 266c includes a plurality of arrays (e g., 4 arrays) of male features 367c disposed on the barrier retainer 266c. The tolerance qxwith the plurality of arrays equals the sum of the width w of the arrays and two times the thickness t of the thermal barrier 260 (i.e., qx= w + 2t). In other words, the thermal barrier 260 is retained in place as long as the right most edge of the arrays engages with the left most edge of the thermal barrier 260 as shown in FIG 3C. Alternatively, the thermal barrier 260 is retained in place as long as the left most edge of the arrays engages with the right most edge of the thermal barrier 260 (not shown). The plurality of arrays of male features 367c enables a tolerance qxgreater than the tolerance zxas illustrated in FIG. 3B.

[0081] FIGS. 4A-9C illustrate some aspects of the male features (also referred to as protrusions) of the barrier retainer, such as the elongated binding strip, gripping feature, textured gripping feature, irregular gripping feature, or semispherical male features. Such barrier retainers are described in detail below.

[0082] FIG. 4A, FIG. 4B, and FIG. 4C each depict an aspect of a barrier retainer 266 with male features similar to the male features 267 in FIG. 2 and male features 367b and 367c respectively shown in FIG. 3B and FIG. 3C. In an aspect, the male features of the barrier retainer 266 include a plurality of elongated binding strips 268 each sized, shaped, and arranged on the barrier retainer 266 to extend along and engage with a peripheral surface of a corresponding individual thermal barrier 260. In one aspect, as shown in FIG. 4A, each elongated binding strip 268 is parallel to an edge e of the barrier retainer 266. In this aspect, the length of each elongated binding strip 268 equals a length of the parallel edge e of the barrier retainer 266. In FIG. 4B and FIG. 4C, the elongated binding strips 268a, 268b, and 268c are arranged from an edge portion (laterally- arranged) to a center portion (medially-arranged) of the barrier retainer 266. In an aspect, each of the elongated binding strips 268 forms a straight edge or blade to perforate or penetrate a corresponding individual thermal barrier 260 along its length. In one aspect shown in FIG. 4B and FIG. 4C, each of the elongated binding strips 268 has a triangular cross section with one angle (corner, vertices) of the triangle pointing away from the barrier retainer 266. This particular comerof the triangle cross-section shape helps perforate or penetrate the thermal barriers 260 easier than other cross-section shapes (e.g., rectangle shape in FIG. 4A).

[0083] As depicted in FIG. 4A, the elongated binding strips 268 extend away from the barrier retainer 266 by approximately the same distance m. Alternatively, as depicted in FIG. 4B and FIG. 4C, the elongated binding strips 268a, 268b, and 268c extend away from the barrier retainer 266 by different distances mi, m2, and m3, respectively. Elongated binding strips with greater distances m perforate further toward a peripheral surface of a corresponding thermal barrier 260 to engage more strongly.

[0084] In aspects shown in FIG. 4B, the distance m gradually increases (mi > m2> m3) from the medially-arranged elongated binding strip 286c to the laterally-arranged elongated binding strips 286a. Such arrangement provides weaker thermal barrier engagement at the center portion of the barrier retainer 266, where the tolerance is greater (as shown in FIG. 3E). As such, the thermal barrier 260 at the center portion can move its position relatively easily to engage with the medially- arranged elongated binding strip(s) 286c. The arrangement in FIG. 4B is especially beneficial for rigid thermal barriers 260 to prevent any damage to the thermal barriers 260.

[0085] In alternative aspects, as shown in FIG. 4C, the distance m gradually decreases (mi < m2 < m3) from the medially-arranged elongated binding strip 286c to the laterally-arranged elongated binding strips 286a. Such arrangement provides stronger thermal barrier engagement at the center portion of the barrier retainer 266, where the tolerance is greater (as shown in FIG. 3E). As such, the thermal barrier at the center portion engages stronger with the medially-arranged elongated binding strips. The arrangement in FIG. 4C is especially beneficial for flexible thermal barriers 260. The edges of the thermal barriers 260 are strongly engaged with the medially-arranged elongated binding strip 268c, while the flexibility of the thermal barrier 260 accommodates the required tolerance.

[0086] FIG. 5A, FIG. 5B, FIG. 5C, FIG. 5D, FIG. 5E, FIG. 5F, FIG. 5G, and FIG. 5H are perspective views depicting aspects of an interface between an elongated binding strip 268 of a barrier retainer 266 and a corresponding thermal barrier 260. In an aspect, an individual thermal barrier 260 can have a thickness between about 0.1 millimeters (mm) and about 50 mm. In an aspect, an individual thermal barrier 260 can have a thickness between about 1 mm and about 10 mm, about 2 mm to about 2.5 mm, from 1.5 mm to about 2.5 mm, and / or from 1.2 mm to about1.8mm. The method and configuration of the thermal barrier retainer 266 enables a smaller tolerance during installation and thereby enables the application of thinner thermal barrier 260.

[0087] FIG. 5A and FIG. 5C (and corresponding magnified views in FIG. 5B and FIG. 5D, respectively) show exploded views and assembled views of an aspect of a thermal barrier 260 engaging with an elongated binding strip 268. The thermal barrier 260 has a groove 563a sized and shaped to receive the elongated binding strip 268 of the barrier retainer 266. In one aspect, a groove 563a extends through the entire length (in Y direction) of the thermal barrier 260. In other words, a length of the groove 563a equals a length of the thermal barrier 260. The groove 563a has a thickness of between about 1 / 10 and about 1 / 3 of the thickness of the individual thermal barrier 260. The elongated binding strip 268 fits into the shape and size of the groove 563a as shown in FIGS. 5C and 5D. An end surface (e.g., the surface in the X-Z plane perpendicular to length in the Y direction) of elongated binding strip 268 is exposed on the side surface (e.g., in the X-Z plane) of the thermal barrier 260 in FIG. 5D. This type of groove 563a is easier to manufacture compared to the groove 563b shown in FIG. 5E and FIG. 5F, wherein the groove 563b does not extend through the entire length of the thermal barrier 260.

[0088] FIG. 5E (and the corresponding magnified view in FIG. 5F) shows an aspect of an interface including a thermal barrier 260 having another aspect of the groove 563b sized and shaped to receive the elongated binding strip 268. Compared to groove 563a in FIGS. 5A-5D that extends through the entire length of the thermal barrier 260, the groove 563b in FIGS. 5E and 5F extends through a portion of the length (e.g., in the Y direction). Thus, the groove 563b does not extend the entire length of the thermal barrier 260, and thus has closed ends in the Y direction. The end surface of the elongated binding strip 268 in the X-Z plane is embedded in the thermal barrier 260 when engaged. A length of the groove 563b is smaller than a length of the thermal barrier 260. The embedded elongated binding strip 268 prevents the corners of the elongated binding strip 268 from inadvertently damaging adjacent battery cells (e.g., pouch cells).

[0089] Also, as shown in FIG. 5G (and corresponding FIG. 5H), another aspect of the thermal barrier 260 has a flat peripheral surface (e.g., the surfaces parallel to the X-Y plane or the X-Z plane) without a groove. The thermal barrier 260 is engaged with, perforated by, or penetrated by the elongated binding strip 268 on the flat peripheral surface upon assembly. The elongated binding strip 268 can engage with any portion of the flat peripheral surface (e.g., the surface in X- Y plane), resulting in a tolerance zxas shown in FIG. 3B. The design in FIG. 5G without the groove563a, 563b is easier to manufacture compared to the designs in FIGS. 5A-5F with the grooves 563a, 563b.

[0090] FIG. 6A and FIG. 6B depict another aspect of an elongated binding strip 268 for engaging a corresponding thermal barrier 260. In an aspect, the individual elongated binding strip 268 includes a row of teeth 565 sized, shaped, and arranged to engage a peripheral surface (e.g., in the X-Y plane) of the corresponding thermal barrier 260. In an aspect, each tooth 565 can extend away from the elongated binding strip 268 at an equal distance p. Alternatively, the teeth 565 may extend away from the elongated by different distances. In one aspect, at least one medial tooth (e.g., positioned, relative to other lateral teeth, more toward a center portion of the elongated binding strip 268) may extend further away from the elongated binding strip 268 than lateral teeth (e.g., positioned, relative to the at least one medial tooth, more toward an end of the elongated binding strip 268).

[0091] FIG. 7A depicts an aspect of a battery unit 700 including elongated binding strips 268 formed onto one or more inner surfaces of the unit housing 264. The one or more inner surfaces of the unit housing 264 serves as the battery retainer to support the elongated binding strips 268. In an aspect, the elongated binding strips 268 can be formed onto the sidewalls (e.g., X-Z plane) and bottom (e.g., X-Y plane) of the unit housing 264. Also, the elongated binding strips 268 can be similarly formed onto a lid 265 of the unit housing 264. This is different from the battery unit 200 in FIG. 2 where the barrier retainer 266 and the lid 265 are two separate parts. Integrating the elongated binding strips 268 onto the lid 264 reduces the cost, weight, and occupied volume of the battery unit 700.

[0092] FIG. 7B depicts an aspect of a barrier retainer 266 having a textured gripping feature (e.g., an array of male features 367c, similar to that depicted in FIG. 3C) formed across a majority of the major surface (i.e., the surface in the X-Y plane of FIG. 7B) of the retainer 266. In an aspect, the textured gripping feature comprises shape or textures selected from at least one of knurling, pyramid, triangular pyramid, cone, needle, threading, diamond plate, checker plate, spherical surface, hemispherical surface texture, sharp geometries, irregular geometries, other suitable geometries, or combinations thereof.

[0093] FIG. 7C and FIG. 7D depict another aspect of a barrier retainer 266 having a textured gripping feature formed across a majority of the surface of the retainer 266. The barrier retainer 266 includes a plurality of protrusions 269a, 269b, 269c, each extending away from the batteryretainer 266. In one aspect, medial-arranged protrusions positioned toward a center of the barrier retainer 266 (e.g., protrusion 269c) extend further away from the barrier retainer 266 than lateral- arranged protrusions (e.g., protrusion 269b and protrusion 269a) positioned toward a periphery of the barrier retainer 266. In other words, protrusions 269c proximate to the center of the barrier retainer 266 have a first “height” dimension extending in the Z axis direction with a greater value than a second “height” dimension extending in the Z axis direction of protrusions 269b, 269a positioned beyond the center region. In one aspect, the first height in the center is greater than the second height at the periphery of the barrier retainer 266. In one aspect, the height dimension decreases linearly from the center to the periphery. In one aspect, the medially-arranged protrusion(s) 269c have different shape and / or size compared to the laterally-arranged protrusions 269b, 269a. In one aspect, the medially-arranged protrusion(s) 269c are larger than the laterally- arranged protrusions 269b, 269a. FIG. 7D shows a different view angle of FIG. 7C to show the differences in protruding distances and sizes. The center of the barrier retainer 266 may have a single protrusion 269c with the first height or may include a plurality of the protrusions 269c with the first height arranged within proximity of the center point.

[0094] FIG. 8A and FIG. 8B each depict aspects of barrier retainers 266 having respective gripping features. In one aspect, as depicted in FIG. 8A, the gripping feature may be a plurality of semispherical male features for engaging an individual thermal barrier 260. he gripping features may be of different sizes, shapes, and / or heights. As depicted in FIG. 8B, the gripping feature may be an irregular, rough surface geometry for protruding against and gripping an individual thermal barrier 260.

[0095] FIG. 9A depicts another aspect of an arrangement of battery cells 252, thermal barriers 260, and a barrier retainer 266 (e.g., having a plurality of binding strips 268). The thermal barrier 260 has at least one expanding edge 971 with a greater thickness than other portions of the thermal barrier 260, such that the expanding edge 971 overlaps with the footprint of the battery cells 252. The at least one expanding edge 971 has a dilated thickness compared to other portions of the barrier 260. The thickness of the thermal barrier 260 may gradually increase as the expending edge 971 extends away from the top surface (at the X-Y plane) of the adjacent battery cell 252. The expanding edge 971 may be a circular sector portion of the thermal barrier 260 with the arc of the circular sector engaging with the barrier retainer 266 when all components are in position withinthe battery unit. The expanding edge 971 provides greater surface area to engage with the binding strips 268 and provides stronger binding strength.

[0096] FIG. 9B depicts an aspect of the thermal barrier 260 with two opposite expanding edges 971. In an aspect, the expanding edges 971 are sized, shaped, and arranged to better engage with the barrier retainer (e.g., at a binding strip 268) compared to the thermal barriers without the expanding edges 971. Also, an individual expanding edge 971 extends beyond the interface with an adjacent battery cell (such as the “footprint” of the adjacent battery cell). As such, the thermal barrier 260 provides wider surface area to bind with the binding strip 268, while still maintaining a thinner thickness between battery cells 252 for cost and space efficiencies. In one aspect, the thermal barrier 260 has uniform thickness in the areas contacting the footprint of the adjacent battery cells (not shown), and flare out to a greater thickness at areas above and below the footprint of the adjacent battery cells.

[0097] FIG. 9C depicts an aspect of the thermal barrier 260 with expanding edges 971 at all four edges. The expanding edges 971 extend beyond the footprint of the battery cell 252. When assembled, the expanding edges 971 extend beyond interfaces of the thermal barrier 260 and adjacent battery cells 252. In other words, the footprint of the adjacent battery cell 252 coincides with the portion of the thermal barrier 260 without the expanding edges 971.

[0098] Battery units and / or battery packs with thermal barriers as described above are used in a number of electronic devices. FIG. 10 illustrates an aspect of an electronic device 1000 that includes a battery unit 1010. The battery unit 1010 is coupled to functional electronics 1020 by circuitry 1012. In the aspect shown, the battery unit 1010 and circuitry 1012 are contained in a housing 1002. A charge port 1014 is shown coupled to the battery unit 1010 to facilitate recharging of the battery unit 1010 when needed.

[0099] In one aspect, the functional electronics 1020 include devices such as semiconductor devices with transistors and storage circuits. Aspects include, but are not limited to, telephones, computers, display screens, navigation systems, etc.

[0100] FIG. 11 illustrates another electronic system that utilizes battery units that include thermal management systems as described herein. An electric vehicle 1100 is illustrated in FIG. 11. The electric vehicle 1100 includes a chassis 1102 and wheels 1122. In the aspect shown, each wheel 1122 is coupled to a drive motor 1120. A battery unit 1110 is shown coupled to the drivemotors 1120 by circuitry 1106. A charge port 1104 is shown coupled to the battery unit 1110 to facilitate recharging of the battery unit 1110 when needed.

[0101] Aspects of electric vehicle 1100 include, but are not limited to, consumer vehicles such as cars, trucks, etc. Commercial vehicles such as tractors and semi-trucks are also within the scope of the invention. Although a four wheeled vehicle is shown, the disclosure is not so limited. In one aspect, two wheeled vehicles, such as motorcycles and scooters, are also within the scope of the present disclosure.

[0102] FIG. 12 is a flowchart illustrating steps for constructing an aspect of a battery unit.

[0103] At 1210, a plurality of battery cells can be arranged within a unit housing. Such arranging can involve positioning each battery cell in a specific configuration to maximize the efficiency of space and to establish the desired electrical connections within the housing.

[0104] At 1220, at least two of the arranged battery cells can be separated by a thermal barrier. The thermal barrier is characterized by an insulator layer that contributes thermal isolation of each cell, thereby mitigating the risk of heat transfer between them.

[0105] At 1230, an individual thermal barrier can be secured to the unit housing via a barrier retainer. The barrier retainer can be positioned to protrude against the at least one thermal barrier, e.g., applying a specified force to ensure that the barriers are firmly secured in their designated positions relative to the unit housing. In one aspect, this can involve perforating or otherwise engaging the peripheral surface of the thermal barrier with protrusions of the barrier retainer. Optionally, the method can include a verification step to confirm that all components of the battery unit are correctly assembled and secured. This verification ensures that the battery unit is assembled in accordance with the prescribed method and is ready for subsequent testing or deployment.

[0106] The following, non-limiting aspects, detail certain aspects of the present subject matter to solve the challenges and provide the benefits discussed herein, among others.

[0107] Aspect 1 is a battery unit, comprising: a plurality of battery cells disposed within a unit housing; at least one thermal barrier arranged between the plurality of battery cells, wherein the at least one thermal barrier includes an insulator layer; and a barrier retainer configured to protrude against the at least one thermal barrier and configured to secure a position of the at least one thermal barrier relative to the unit housing.

[0108] In Aspect 2, the subject matter of Aspect 1 includes, wherein the barrier retainer includes one or more protrusions to engage a peripheral surface of the at least one thermal barrier.

[0109] In Aspect 3, the subject matter of Aspect 1 or 2 includes, wherein the barrier retainer includes one or more protrusions to perforate a peripheral surface of the at least one thermal barrier.

[0110] In Aspect 4, the subject matter of Aspect 3, wherein the at least one thermal barrier has a thickness between about 0.1 millimeters and about 30 millimeters.

[0111] In Aspect 5, the subject matter of Aspects 1-4 includes, wherein the barrier retainer includes one or more elongated binding strips arranged to extend along and engage with a peripheral surface of a corresponding one of the at least one thermal barrier.

[0112] In Aspect 6, the subject matter of Aspect 5 includes, wherein the at least one thermal barrier comprises a receiving slot to receive the one or more elongated binding strips.

[0113] In Aspect 7, the subject matter of Aspect 6 includes, wherein the one or more elongated binding strips include at least one row of teeth, each tooth in the at least one row of teeth configured to engage with the peripheral surface of the at least one thermal barrier.

[0114] In Aspect 8, the subject matter of Aspect 7 includes, wherein the receiving slot has a compartment for each tooth.

[0115] In Aspect 9, the subject matter of Aspect 7 includes, wherein the at least one row of teeth includes at least one medial tooth extending further away than other teeth from the barrier retainer.

[0116] In Aspect 10, the subject matter of Aspect 3 includes, wherein the one or more protrusions distribute across a major surface of the barrier retainer.

[0117] In Aspect 11, the subject matter of Aspects 2, 3, or 10 includes, wherein the one or more protrusions have different sizes.

[0118] In Aspect 12, the subject matter of Aspect 11 includes, wherein a first set of the one or more protrusions in a first region of the barrier retainer have a height dimension that is greater than the height dimension of a second set of the one or more protrusions in a second region of the barrier retainer.

[0119] In Aspect 13, the subject matter of Aspects 5-7 includes, wherein: each of the one or more elongated binding strips is configured to extend along and perforate a peripheral surface of a corresponding individual one of the at least one thermal barrier; and wherein at least one medially-arranged elongated binding strip penetrates further into the peripheral surface of thecorresponding individual one of the at least one thermal barrier than a plurality of laterally- arranged elongated binding strips penetrate into respective peripheral surfaces of corresponding individual thermal barriers.

[0120] In Aspect 14, the subject matter of Aspects 5-7 or 13 includes, wherein the one or more elongated binding strips includes a textured gripping feature including at least one of knurling, pyramid, cone, threading, diamond plate texture, checker plate texture, or hemispherical surface texture.

[0121] In Aspect 15, the subject matter of Aspects 5-7, 13, or 14 includes, wherein the one or more elongated binding strips are arranged on one or more inner surfaces of the battery housing.

[0122] In Aspect 16, the subject matter of Aspect 15 includes, wherein the barrier retainer is one or more inner surfaces of the battery housing with protrusions, wherein optionally the protrusions have a rough gripping surface texture.

[0123] In Aspect 17, the subject matter of Aspect 16 includes, wherein the barrier retainer includes a plurality of the protrusions, wherein medial -arranged protrusions extend further away from the barrier retainer than lateral -arranged protrusions.

[0124] In Aspect 18, the subject matter of Aspects 2-17 includes, wherein the at least one thermal barrier includes at least one expanding edge to engage with the protrusions, the at least one expanding edge having a dilated thickness compared to other portions of the at least one thermal barrier.

[0125] In Aspect 19, the subject matter of Aspect 18 includes, wherein the at least one expanding edge extends beyond interfaces of the at least one thermal barrier and adjacent battery cells.

[0126] In Aspect 20, the subject matter of Aspects 1-19 includes, wherein the at least one thermal barrier includes a dielectric reinforcing layer.

[0127] Aspect 21 is at least one machine-readable medium including instructions that, when executed by processing circuitry, cause the processing circuitry to perform operations to implement of any of Aspects 1-20.

[0128] Aspect 22 is an apparatus comprising means to implement of any of Aspects 1- 20.

[0129] Aspect 23 is a system to implement of any of Aspects 1-20.

[0130] Aspect 24 is a method to implement of any of Aspects 1-20.

[0131] The above Detailed Description can include references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as “aspects.” Such aspects can include elements in addition to those shown or described. However, the present inventors also contemplate aspects in which only those elements shown or described are provided. Moreover, the present inventors also contemplate aspects using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular aspect (or one or more aspects thereof), or with respect to other aspects (or one or more aspects thereof) shown or described herein.

[0132] In the event of inconsistent usages between this document and any documents so incorporated by reference, the usage in this document controls. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, composition, formulation, or process that can include elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim.

[0133] In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” can include “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, composition, formulation, or process that can include elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0134] The above description is intended to be illustrative, and not restrictive. In one aspect, the above-described aspects (or one or more aspects thereof) can be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R. § 1.72(b), toallow the reader to quickly ascertain 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 can be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter can lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description as aspects or embodiments, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

What is claimed is:

1. A battery unit, comprising: a plurality of battery cells disposed within a unit housing; at least one thermal barrier arranged between the plurality of battery cells, wherein the at least one thermal barrier includes an insulator layer; and a barrier retainer configured to protrude against the at least one thermal barrier and configured to secure a position of the at least one thermal barrier relative to the unit housing.

2. The battery unit of claim 1, wherein the barrier retainer includes one or more protrusions to engage a peripheral surface of the at least one thermal barrier.

3. The battery unit of claim 1 or 2, wherein the barrier retainer includes one or more protrusions to perforate a peripheral surface of the at least one thermal barrier.

4. The battery unit of claim 1, wherein each of the at least one thermal barrier has a thickness between about 0.1 millimeters and about 30 millimeters.

5. The battery unit of any one of claims 1-4, wherein the barrier retainer includes one or more elongated binding strips arranged to extend along and engage with a peripheral surface of a corresponding one of the at least one thermal barrier.

6. The battery unit of claim 5, wherein the at least one thermal barrier comprises a receiving slot to receive the one or more elongated binding strips.

7. The battery unit of claim 6, wherein the one or more elongated binding strips include at least one row of teeth, each tooth in the at least one row of teeth configured to engage with the peripheral surface of the at least one thermal barrier.

8. The battery unit of claim 7, wherein the receiving slot has a compartment for each tooth.

9. The battery unit of claim 7, wherein the at least one row of teeth includes at least one medial tooth extending further away than other teeth from the barrier retainer.

10. The battery unit of claim 3, wherein the one or more protrusions are distributed across a major surface of the barrier retainer.

11. The battery unit of any one of claims 2, 3, or 10, wherein the one or more protrusions have different sizes.

12. The battery unit of claim 11, wherein a first set of the one or more protrusions in a first region of the barrier retainer have a height dimension that is greater than the height dimension of a second set of the one or more protrusions in a second region of the barrier retainer.

13. The battery unit of any one of claims 5-7, wherein: each of the one or more elongated binding strips is configured to extend along and perforate a peripheral surface of a corresponding individual one of the at least one thermal barrier; and wherein at least one medially-arranged elongated binding strip penetrates further into the peripheral surface of the corresponding individual one of the at least one thermal barrier than a plurality of laterally-arranged elongated binding strips penetrate into respective peripheral surfaces of corresponding individual thermal barriers.

14. The battery unit of any one of claims 5-7 or 13, wherein the one or more elongated binding strips includes a textured gripping feature including at least one of knurling, pyramid, cone, threading, diamond plate texture, checker plate texture, or hemispherical surface texture.

15. The battery unit of any one of claims 5-7, 13, or 14, wherein the one or more elongated binding strips are arranged on one or more inner surfaces of a battery housing.

16. The battery unit of claim 15, wherein the barrier retainer is one or more inner surfaces of the battery housing with protrusions.

17. The battery unit of claim 16, wherein the barrier retainer includes a plurality of the protrusions, and wherein medial-arranged protrusions extend further away from the barrier retainer than lateral-arranged protrusions.

18. The battery unit of any one of claims 2-17, wherein the at least one thermal barrier includes at least one expanding edge to engage with the protrusions, the at least one expanding edge having a dilated thickness compared to other portions of the at least one thermal barrier.

19. The battery unit of claim 18, wherein the at least one expanding edge extends beyond interfaces of the at least one thermal barrier and adjacent battery cells.

20. The battery unit of any one of claims 1-19, wherein the at least one thermal barrier includes a dielectric reinforcing layer.

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