EP4684445A1

EP4684445A1 - Battery pack with battery module partially submerged in coolant

Info

Publication number: EP4684445A1
Application number: EP24715070.9A
Authority: EP
Inventors: David Sullivan
Original assignee: SABIC Global Technologies BV
Current assignee: SABIC Global Technologies BV
Priority date: 2023-03-21
Filing date: 2024-03-19
Publication date: 2026-01-28
Also published as: WO2024194309A1; CN120883422A

Abstract

Examples can include a method of constructing a battery pack for an electrical vehicle, including disposing at least one battery module fixedly in a lower tray. Examples can include covering the lower tray with an intermediate baffle, defining a coolant reservoir located between the lower tray and the intermediate baffle, with the at least one battery module extending through a battery module opening of the intermediate baffle partially, with electrical couplings of the at least one battery module located above the intermediate baffle and a remainder of the at least one battery module disposed below the intermediate baffle in the coolant reservoir. Examples can include sealing the intermediate baffle to the at least one battery module to sealedly retain coolant in the coolant reservoir.

Description

BATTERY PACK WITH BATTERY MODULE PARTIALLY SUBMERGED IN COOLANT

TECHNICAL FIELD

[0001] The present subject matter relates to battery packs, and more specifically to a battery pack with immersion cooling for partially submerged battery modules, wherein cooling can be provided by sloshing.

BACKGROUND

[0002] As the demand for high-performance and energy-efficient batteries continues to grow, the need for effective thermal management strategies to control battery temperature has become increasingly important. One approach that has gained traction in recent years is immersion cooling, which involves submerging batteries in a coolant. For instance, European Patent Application No. EP3742541A1 and European Patent Application No. EP3477764A1 each reference immersion cooling, but among other shortcomings do not reference controlling to flow of coolant due to stop-go motion. Similarly, United States Patent Application US20220314837A1 describes a fully submerged battery cell array, but is silent as to how to control the flow of coolant within due to stop-go motion.

SUMMARY

[0003] To address these and other shortcomings, the present subject matter provides an immersion cooled battery pack with one or more intermediate baffles to constrain the location of coolant with respect to battery cells or modules.

[0004] Further, the present subject matter addresses a concern with immersion cooling in that sensitive electronics may react with coolant. In some designs, it is desirable to keep the coupling electronics “dry”, at least to facilitate in-pack construction, or to ensure coolant doesn’t react with exposed conductors.

[0005] Another problem is that immersion cooling systems can be expensive to operate - pumps and couplings can be expensive to build and assemble.

[0006] To address the shortcoming described above, the present disclosure provides a battery pack with partially submerged battery modules. An example utilizes sloshing inherent with the stop/start behavior of a motor vehicle. Other benefits are discussed, including improved conduction and the potential to reduce or eliminate the use of thermally conductive paste in the battery pack.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The following drawings illustrate by way of example and not limitation. For the sake of brevity and clarity, every feature of a given structure is not always labeled in every figure in which that structure appears. Identical reference numbers do not necessarily indicate an identical structure. Rather, the same reference number can be used to indicate a similar feature or a feature with similar functionality, as may non-identical reference numbers.

[0008] FIG. 1 shows a top view of a battery pack, according to some examples.

[0009] FIG. 2 shows a cross-section side view of the battery pack of FIG. 1 taken at line 2 - - 2 in FIG. 1.

[0010] FIG. 3 shows a perspective view of an intermediate baffle and battery modules, according to some examples.

[0011] FIG. 4 shows a top view of an intermediate baffle and staggered hexahedral battery modules, according to some examples.

[0012] FIG. 5 shows a top view of an intermediate baffle and staggered cylindrical battery modules, according to some examples.

[0013] FIG. 6 shows a close up sectional view of a joint, taken along 6 — 6 in FIG. 2.

[0014] FIG. 7 shows a close-up section view of a joint, according to some examples.

[0015] FIG. 8 shows a close-up section view of a joint, according to some examples.

[0016] FIG. 9A shows a side view of a battery pack, according to some examples.

[0017] FIG. 9B shows atop view of the battery pack of FIG. 9A.

[0018] FIG. 9C shows a perspective view of the battery pack of FIG. 9A, according to some examples. [0019] FIG. 9D shows a cross-section of the batery pack of FIG. 9 A taken along line 9D - - 9D.

[0020] FIG. 10 shows a perspective view of a lower tray, according to some examples.

[0021] FIG. 11 shows a method of cooling a batery pack, according to some examples.

DETAILED DESCRIPTION

[0022] One challenge to operating electric vehicles is the heat generated by charging and discharging. As batery calendar life is affected by the magnitude of thermal cycles, it is desirable to maintain batery cells or modules with a specified temperature range. Another challenge is maintain cells within a batery pack below a threshold at which thermal runaway may be experienced. While immersion cooling, as applied to static systems (Known cooling techniques can aid in the maintenance of cells at a desired temperature, but in many cases coolant in these systems does not provide a large enough heat sink.

[0023] An objective of the present subject mater is to provide a large heat sink for cells to reside in. By disposing cells or modules in a large coolant reservoir, they can be placed in desirable thermal conductivity with a large heat sink, an arrangement that can encourage maintenance of cells or modules within a desired temperature range. The present disclosure also provides a large heatsink for heat energy to flow into in cases of thermal anomaly. The present subject matter can use agitators or pumps to circulate coolant, but can also use vehicle stop-go motion to circulate coolant, complimenting naturally occurring convection currents. The disclosed examples can eliminate problematic thermal conductivity solutions, such as thermally conductive past.

[0024] FIG. 1 shows a top view of a batery pack 100, according to an example. FIG. 2 shows a side view of the batery pack of FIG. 1 in cross section taken along line 2 - - 2. A top cover 102 is shown. Batery modules 104 are show in hidden line. An auxiliary reservoir 106 can be optionally coupled to the batery pack 100. The batery pack 100 can include a lower tray 108. The lower tray 108 can be adapted to retain at least one batery module 110. The at least one batery module can be disposed in the lower tray. The at least one battery module can comprise electrical couplings 112. The electrical couplings 112 can be in electrical communication with cells of the at least one battery module, not pictured.

[0025] An intermediate baffle 114 can be coupled to the lower tray. Coupling the intermediate baffle 114 to the lower tray can define a coolant reservoir 116. The coolant reservoir 116 can be located between the lower tray and the intermediate baffle. The intermediate baffle 114 can define a battery module opening 118. At least one battery module 104 can be disposed through the battery module opening 118. The at least one battery module 104 can be at least partially disposed in the coolant reservoir. The electrical couplings 112 can extend above the intermediate baffle 114. The electrical couplings 112 can be disposed opposite the coolant reservoir 116.

[0026] Coolant 124 can be sealed in the coolant reservoir 116. The coolant reservoir 116 can be hermetically sealed. A seal 120 can be coupled between the intermediate baffle 114 and the at least one battery module 110. The seal 120 can be configured to retain coolant 124 in the coolant reservoir 116. The seal 120 can be formed of adhesive. The seal 120 can be a pre-formed gasket. A gasket can be formed of a pliable material defining an inner gasket lumen. The coolant 124 can be dielectric. The battery module 110 can define a regular hexahedron, or another shape, such as rhombic dodecahedron.

[0027] The top cover 102 can be coupled to the lower tray 108, with the intermediate baffle 114 coupled inside the battery pack 100 to at least one of the top cover 102 and the lower tray 108. The intermediate baffle 114 can be coupled to the lower tray 108, and the top cover 102 can be coupled with at least one of the lower tray 108 and the intermediate baffle 114. The top cover 102 can be sized to extend over the electrical couplings 112 to define an electrical coupling plenum 121. The electrical couplings 112 can be disposed in the electrical coupling plenum 121. The electrical couplings 112 can be covered with a sealant.

[0028] The electrical coupling plenum 121 can be in fluid communication with the coolant reservoir 116 such that coolant 124 in the coolant reservoir can slosh in the coolant reservoir 116. This can be allowed by a large difference in bulk modulus of the coolant 124 versus gas in the electrical coupling plenum 121. A gas in the electrical coupling plenum 121 can be air, such as earth atmosphere, or another gas, such as nitrogen, a gaseous fire suppressant such as an inert gas to displace oxygen, and the like.

[0029] The intermediate baffle 114 can define at least one intermediate baffle fluid passage 122 such that the electrical coupling plenum is in fluid communication with the coolant reservoir 116. The at least one intermediate baffle fluid passage can be an orifice. The at least one intermediate baffle fluid passage can be a one-way valve. The one-way valve can be a reed valve. The one-way valve can be a check valve. The check valve can be a ball-type check valve. The ball of the ball-type check valve can be buoyant in the coolant 124.

[0030] The top cover 102 can include one or more top cover air foils, such as fins, disposed on an outer portion of the top cover, opposite the intermediate baffle, in thermal communication with a remainder of the top cover, the one or more top cover airfoils to cool the top cover. The top cover can define one or more channels extending through or adjacent the electrical coupling plenum to direct air that is exterior of the battery pack through the electrical coupling plenum. Such airflow can be used to cool the electrical coupling plenum, for example.

[0031] The lower tray can include one or more lower tray air foils, such as fins, disposed on an outer portion of the lower tray, in thermal communication with a remainder of the lower tray, the one or more lower tray airfoils to cool the lower tray.

[0032] At least one auxiliary baffle 126 can be disposed below the intermediate baffle 114, the at least one auxiliary baffle 126 configured to control coolant flow in the coolant reservoir 116. The auxiliary baffle 126 can be parallel to the intermediate baffle 114. The auxiliary baffle 126 can be perpendicular to the intermediate baffle 114, as pictured. The at least one auxiliary baffle 126 can be an adjustable baffle configured to variably control fluid-flow therethrough. The auxiliary baffle can be adjusted to control the rate of movement of coolant 124 around the coolant reservoir 116, so as to control the rate of motion imparted onto a vehicle via movement of coolant 124 in the battery pack 100.

[0033] The coolant 124 can be in fluid communication with a secondary reservoir external to the battery pack. The secondary reservoir can be coupled to a remainder of the battery pack 100 similarly to the auxiliary reservoir 106, pictured. The secondary reservoir can be a heat exchanger. For example, a cooling plate can be submerged in the coolant reservoir, or placed adjacent the lower tray proximal the coolant reservoir to add or remove heat from the coolant 124. The secondary reservoir can be a bladder or accumulator. A bladder or accumulator can control pressure in the coolant reservoir 116, such as to keep a constant pressure on the coolant reservoir 116 above ambient pressure or below ambient pressure, with ambient pressure being extra-vehicular or a pressure in another portion of the battery pack 100.

[0034] The approach in FIG. 1 can enable assembly or service of the battery pack with coolant remaining in place. For example, a battery pack can be assembled by disposing modules in a lower tray, disposing coolant in the lower tray, and assembling an intermediate baffle to the lower tray, around the battery modules, to seal the coolant in a coolant reservoir.

[0035] Previous battery pack cooling approaches have relied on a sealed cooling play disposed adjacent battery cells or modules. To promote thermal conduction between the cooling plate and the battery cells, thermally conductive pastes are used. These pastes are notoriously expensive and unreliable - it is expected the hard use case of vehicles can damage the thermal pathways they provide. The present subject matter reduces or eliminates the need for such thermal conduction promoters, which can result in better thermal conductivity.

[0036] The present subject matter also provides an approach for passive cooling, relying on sloshing and convection to circulate coolant. Some approaches can even use an external heat exchanged, such as a radiator, to circulate coolant and provide for cooling.

[0037] The present subject matter also can address thermal runaway by providing a large heat-sink for cells, such that one cell in thermal runaway may not spread to its neighbors.

[0038] The at top cover, interior baffle, and/or lower tray, among other components, can be formed of various materials. Aluminum can be used, but aluminum often does not provide the performance benefits of a thermoplastic resin, such as light weight. Thus, various approaches use resin components. [0039] The resin material can be formed of a polymeric composition comprising a thermoplastic polymer. The thermoplastic polymer is not particularly limited and can include at least one of a polyacetal, a polyacrylic, a polycarbonate, a polystyrene, a polyester, a polyamide, a polyamideimide, a polyarylate, a polyarylsulfone, a polyethersulfone, a polyphenylene sulfide, a polysulfone, a polyimide, a poly etherimide, a fluoropolymer (for example, polytetrafluoroethylene), a poly etherketone, a poly ether ether ketone, a poly ether ketone ketone, a polybenzoxazole, a poly oxadiazole, a polybenzimidazole, a polyacetal, a polyanhydride, a poly(vinyl ether), a poly(vinyl thioether), a poly(vinyl alcohol), a poly(vinyl ketone), a poly(vinyl halide), a poly(vinyl nitrile), a poly(vinyl ester), a poly sulfonate, a poly sulfide, a poly sulfonamide, a polyurea, or a polyphosphazene. The thermoplastic polymer can include a polyolefin, a polycarbonate, a polysulfone, a poly etherimide, a polyamide, a polyester (for example, polyethylene terephthalate) or poly(butylene terephthalate), a polystyrene, a polyether (for example, a polyether ketone or a poly ether ether ketone), or a polyacrylate (for example, poly(methyl methacrylate).

[0040] The thermoplastic polymer can comprise a polyolefin. The polyolefin comprises at least one of a homopolymer or a copolymer. The polyolefin can be of the general structure: CnH2n, where n can be 2 to 20. The polyolefin can include at least one of a polyethylene, a polypropylene, a polyisobutylene, or a polynorbomene. Examples of polyethylene include linear low density polyethylene (LLDPE), high density polyethylene (HDPE), and medium density polyethylene (MDPE). The polyolefin can include a polyolefin copolymer, for example, copolymers of ethylene and at least one of propene, 1 -butene, 1 -octene, 1 -decene, 4-methylpentene-l, 2- butene, 1 -pentene, 2-pentene, 1 -hexene, 2-hexene, 3 -hexene, norbomene, or a diene (for example, 1,4 hexadiene, monocylic or polycyclic dienes). The polyolefin copolymer can include a heterophasic polyolefin. , the thermoplastic polymer can include a polyethylene.

[0041] The thermoplastic composition can include an additive. The additive can include at least one of a foaming agent, a flame retardant, an impact modifier, flow modifier, filler (e.g., a particulate polytetrafluoroethylene (PTFE), glass, carbon, mineral, or metal), reinforcing agent (e.g., glass fibers), antioxidant, heat stabilizer, light stabilizer, ultraviolet (UV) light stabilizer, UV absorbing additive, plasticizer, lubricant, release agent (such as a mold release agent), antistatic agent, anti-fog agent, antimicrobial agent, colorant (e.g., a dye or pigment), surface effect additive, radiation stabilizer, anti-drip agent (e.g., a PTFE-encapsulated styrene-acrylonitrile copolymer (TSAN)), or a combination thereof. For example, a combination of a heat stabilizer, mold release agent, and ultraviolet light stabilizer can be used. In general, the additives are used in the amounts generally known to be effective.

[0042] The thermoplastic composition can include a foaming agent that, e.g., foams at about 240 °C. The presence of the foaming agent can function to absorb heat energy to potentially prevent thermal runaway or to prevent oxygen from contacting the surface of the polymer during combustion (intumescence) . The foaming agent can include a solid foaming agent, a liquid foaming agent, or a supercritical foaming agent. The foaming agent can be a solid at room temperature and, when heated to temperatures higher than its decomposition temperature, generate a gas (for example, nitrogen, carbon dioxide, or ammonia gas), such as azodicarbonamide, metal salts of azodicarbonamide, 4,4' oxybis(benzenesulfonylhydrazide), sodium bicarbonate, ammonium carbonate, or the like. The foaming agent can include at least one of an inorganic agent or an organic agents. Examples of inorganic blowing agents include carbon dioxide, nitrogen, argon, water, air, nitrogen, ammonia, and inert gases for example helium and argon. Examples of organic agents include aliphatic hydrocarbons having 1 to 9 carbon atoms, aliphatic alcohols having 1 to 3 carbon atoms, and fully and partially halogenated aliphatic hydrocarbons having 1 to 4 carbon atoms. Examples of aliphatic hydrocarbons include methane, ethane, propane, n-butane, isobutane, n- pentane, isopentane, neopentane, and the like. Examples of aliphatic alcohols include methanol, ethanol, n-propanol, and isopropanol. Examples of fully and partially halogenated aliphatic hydrocarbons include fluorocarbons, chlorocarbons, and chlorofluorocarbons. Examples of fluorocarbons include methyl fluoride, perfluoromethane, ethyl fluoride, 1,1 -difluoroethane, 1,1,1 -trifluoroethane, 1, 1,1,2- tetrafluoro-ethane, pentafluoroethane, difluoromethane, perfluoroethane, 2,2- difluoropropane, 1,1,1 -trifluoropropane, perfluoropropane, di chloropropane, difluoropropane, perfluorobutane, perfluorocyclobutane, and the like. Examples of partially halogenated chlorocarbons and chlorofluorocarbons include methyl chloride, methylene chloride, ethyl chloride, 1,1,1 -tri chloroethane, 1,1 -di chloro- 1 -fluoroethane, 1 -chloro- 1 , 1 -difluoroethane, chlorodifluoromethane, 1 , 1 -dichloro-2,2,2- trifluoroethane, l-chloro-l,2,2,2-tetrafluoroethane, and the like. Examples of fully halogenated chlorofluorocarbons include trichloromonofluoromethane, dichlorodifluoromethane, tri chlorotrifluoroethane, 1,1,1 -trifluoroethane, pentafluoroethane, dichlorotetrafluoroethane, chloroheptafluoropropane, and dichlorohexafluoropropane. Examples of other chemical agents include azodicarbonamide, azodiisobutyronitrile, benzenesulfonhydrazide, 4,4-oxybenzene sulfonyl-semicarbazide, p-toluene sulfonyl semi-carbazide, barium azodicarboxylate, N,N'-dimethyl-N,N'-dinitrosoterephthalamide, trihydrazino triazine, and the like.

[0043] A resin material can include a flame retardant, such as, for example, a phosphate structure (e.g., resorcinol bis(diphenyl phosphate)), a sulfonated salt, halogen, phosphorous, talc, silica, a hydrated oxide, a brominated polymer, a chlorinated polymer, a phosphorated polymer, a nanoclay, an organoclay, a polyphosphonate, a poly[phosphonate-co-carbonate], a polytetrafluoroethylene and styrene-acrylonitrile copolymer, a polytetrafluoroethylene and methyl methacrylate copolymer, a polysilixane copolymer, and/or the like.

[0044] Examples of halogenated flame retardants include bisphenols of which the following are representative: 2,2-bis-(3,5-dichlorophenyl)-propane; bis-(2- chlorophenyl)-methane; bis(2,6-dibromophenyl)-methane; l,l-bis-(4-iodophenyl)- ethane; l,2-bis-(2,6-dichlorophenyl)-ethane; l,l-bis-(2-chloro-4-iodophenyl)ethane;

1.1-bis-(2-chloro-4-methylphenyl)-ethane; l,l-bis-(3,5-dichlorophenyl)-ethane; 2,2- bis-(3-phenyl-4-bromophenyl)-ethane; 2,6-bis-(4,6-dichloronaphthyl)-propane; and

2.2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane 2,2 bis-(3-bromo-4-hydroxyphenyl)- propane. Other halogenated materials include 1,3-di chlorobenzene, 1,4- dibromobenzene, l,3-dichloro-4-hydroxybenzene, and biphenyls such as 2,2'- di chlorobiphenyl, polybrominated 1,4-diphenoxy benzene, 2,4'-dibromobiphenyl, and 2,4'-dichlorobiphenyl as well as decabromo diphenyl oxide, as well as oligomeric and polymeric halogenated aromatic compounds, such as a copolycarbonate of bisphenol A and tetrabromobisphenol A and a carbonate precursor, e.g., phosgene. Metal synergists, e.g., antimony oxide, can also be used with the flame retardant. When present, halogen containing flame retardants can be present in amounts of 1 to 25 parts by weight, or 2 to 20 parts by weight, based on 100 parts by weight of the total composition, excluding any filler.

[0045] Alternatively, the thermoplastic composition can be essentially free of chlorine and bromine. “Essentially free of chlorine and bromine” is defined as having a bromine or chlorine content of less than or equal to 100 parts per million by weight (ppm), less than or equal to 75 ppm, or less than or equal to 50 ppm, based on the total parts by weight of the composition, excluding any filler.

[0046] The flame retardant can comprise a phosphorus containing flame retardant. Flame retardant aromatic phosphates include triphenyl phosphate, tricresyl phosphate, isopropylated triphenyl phosphate, phenyl bis(dodecyl) phosphate, phenyl bis(neopentyl) phosphate, phenyl bis(3,5,5'-trimethylhexyl) phosphate, ethyl diphenyl phosphate, 2-ethylhexyl di(p-tolyl) phosphate, bis(2-ethylhexyl) p-tolyl phosphate, tritolyl phosphate, bis(2-ethylhexyl) phenyl phosphate, tri(nonylphenyl) phosphate, bis(dodecyl) p-tolyl phosphate, dibutyl phenyl phosphate, 2-chloroethyl diphenyl phosphate, p-tolyl bis(2,5,5'-trimethylhexyl) phosphate, and 2-ethylhexyl diphenyl phosphate. Di- or polyfunctional aromatic phosphorus-containing compounds are also useful, for example resorcinol tetraphenyl diphosphate (RDP), the bis(diphenyl) phosphate of hydroquinone and the bis(diphenyl) phosphate of bisphenol A, respectively, and their oligomeric and polymeric counterparts. Flame retardant compounds containing phosphorus-nitrogen bonds include phosphonitrilic chloride, phosphorus ester amides, phosphoric acid amides, phosphonic acid amides, phosphinic acid amides, and tris(aziridinyl) phosphine oxide. The aromatic phosphate can include a di- or polyfunctional compound or polymer. When used, phosphorus- containing flame retardants can be present in amounts of 0.1 to 30 parts by weight, or 1 to 20 parts by weight, based on 100 parts by weight of the total composition, excluding any filler.

[0047] Inorganic flame retardants include salts of C 1-16 alkyl sulfonate salts such as potassium perfluorobutane sulfonate (Rimar salt), potassium perfluoroctane sulfonate, tetraethylammonium perfluorohexane sulfonate, and potassium diphenylsulfone sulfonate; salts such as Na2CO3, K2CO3, MgCO3, CaCO3, and BaCO3, or fluoro-anion complexes such as Li3AlF6, BaSiF6, KBF4, K3A1F6, KA1F4, K2SiF6, or Na3AlF6. When present, inorganic flame retardant salts can be present in amounts of 0.01 to 10 parts by weight, or 0.02 to 1 parts by weight, based on 100 parts by weight of the total composition, excluding any filler.

[0048] The thermoplastic composition can have a UL94 flame rating of V0 or better at a non-limiting thickness of 3.5 millimeters (mm), preferably 2 mm, or 1.5 mm, or 1 mm, or less, as measured in accordance with the Underwriter’s Laboratory Bulletin 94 (UL94) entitled “Tests for Flammability of Plastic Materials for Parts in Devices and Appliances” (ISBN 0-7629-0082-2), Fifth Edition, Dated October 29, 1996, incorporating revisions through and including December 12, 2003.

[0049] At least one article, such as the top cover, the interior baffle, and the lower tray, can be formed of a composite. A composite can be formed of a chopped long-glass fiber reinforced thermoplastic. The plastic lamina can be fused to continuous -fiber reinforced composite lamina. Ribbing can be fused onto the fiber reinforced composite. At least one of the top cover, the interior baffle, and the lower tray can be formed of a continuous-fiber reinforced composite lamina. Continuous- fiber reinforced composite lamina can be formed of a unidirectional tape with continuous fibers disposed in a thermoplastic matrix.

[0050] If included, the articles can comprise fibers having one or more of the present compositions (e.g., made by passing the composition(s)-either melted or dissolved in a solvent-through a spinneret), carbon fibers, glass fibers, aramid fibers, ceramic fibers, basalt fibers, volcanic ash fibers, natural fibers, and/or the like. In some articles, the fibers can be dispersed within a matrix material comprising, for example, one or more of the present compositions, a thermoplastic material, and/or a thermoset material.

[0051] The fibers can be arranged in any suitable fashion. To illustrate, the fibers can be aligned in a single direction. For example, the lamina can be unidirectional (e.g., a unidirectional tape). The fibers can be arranged in a woven configuration, such as in a plane, twill, satin, basket, leno, mock leno, or the like weave. Lamina of a composite can be non-woven (e.g., dry-laid, wet-laid, spunmelt, or the like), in which the fibers are multi-directional, arranged in a sheet or web, and connected to one another via entanglement and/or thermal and/or chemical bonds rather than in a weave or knit. The unidirectional tape can have an arrangement in which many strands of continuous fiber longitudinally extend in the same direction (strand arrangement), and the continuous fiber fabric can have a woven structure in which the continuous fibers cross each other in the longitudinal and latitudinal directions. The continuous fiber of a unidirectional (UD) or woven type can be used. Some examples of the woven type may include plain, twill, and satin types woven at 0°/90° and a type woven at 0°/90^o/-45^o/45°. When a reinforcement lamina in which the continuous fiber is arranged in one direction is used (for example, the unidirectional tape is used as a fiber reinforced material), the continuous fibers in the reinforcement lamina can be arranged in a "crossing direction" with respect to the forward and backward longitudinal direction of the cover (i.e., the continuous fibers in the reinforcement lamina can be arranged in the right and left width direction with respect to the forward and backward longitudinal direction of the cover).

[0052] The present compositions can also be included in skin-core (e.g., sandwich, ABA, and the like) composites. By way of example, the core can include foam (e.g., open- or closed-cell), a honeycomb structure, balsa wood, and/or the like, and the skin(s) can include fiber-reinforced laminate(s). Such a skin-core composite can comprise one or more of the present compositions in that its skin(s) can include one or more of any of the laminae and laminates described above and/or its core can comprise one or more of the present compositions.

[0053] Molding materials that include one or more of the present compositions, suitable for use in, for example, injection molding and/or compression molding, can be used. Such molding material can be provided as pellets. The disclosed molding materials can include a filler, such as talc, calcium carbonate, discontinuous or short fibers (e.g., including any of the fiber-types described above), and/or the like.

[0054] A composite resin, known as a matrix material, can include one or more additives, such as, for example, a coupling agent to promote adhesion between the matrix material and fibers of the unidirectional tape, an antioxidant, a heat stabilizer, a flow modifier, a stabilizer, a UV stabilizer, a UV absorber, an impact modifier, a cross-linking agent, a colorant, or a combination thereof. Examples of a coupling agent include POLYBOND 3150 maleic anhydride grafted polypropylene, commercially available from DUPONT, FUSABOND P613 maleic anhydride grafted polypropylene, commercially available from DUPONT, maleic anhydride ethylene, or a combination thereof. An example of a flow modifier is CR20P peroxide masterbatch, commercially available from POLYVEL INC. An example of a heat stabilizer is IRGANOX B 225, commercially available from BASF. Examples of UV stabilizers include hindered amine light stabilizers, hydroxybenzophenones, hydroxyphenyl benzotriazoles, cyanoacrylates, oxanilides, hydroxyphenyl triazines, and combinations thereof. Examples of UV absorbers include 4-substituted-2- hydroxybenzophenones and their derivatives, aryl salicylates, monoesters of diphenols, such as resorcinol monobenzoate, 2-(2-hydroxyaryl)-benzotriazoles and their derivatives, 2-(2 -hydroxy ary 1)-1, 3, 5-triazines and their derivatives, or combinations thereof. Examples of impact modifiers include elastomers/soft blocks dissolved in one or more matrix-forming monomers (e.g., bulk HIPS, bulk ABS, reactor modified PP, LOMOD, LEXAN EXL, and/or the like), thermoplastic elastomers dispersed in a matrix material by compounding (e.g., di-, tri-, and multiblock copolymers, (functionalized) olefin (co)polymers, and/or the like), predefined core-shell (substrate-graft) particles distributed in a matrix material by compounding (e.g., MBS, ABS-HRG, AA, ASA-XTW, SWIM, and/or the like), or combinations thereof. Examples of cross-linking agents include include divinylbenzene, benzoyl peroxide, alkylenediol di(meth)acrylates (e.g., glycol bisacrylate and/or the like), alkylenetriol tri(meth)acrylates, polyester di(meth)acrylates, bisacrylamides, triallyl cyanurate, triallyl isocyanurate, allyl (meth)acrylate, diallyl maleate, diallyl fumarate, diallyl adipate, triallyl esters of citric acid, triallyl esters of phosphoric acid, or combinations thereof. In some unidirectional tapes, such an additive can comprise neat polypropylene.

[0055] FIG. 3 shows a perspective view of an intermediate baffle and battery modules, according to some examples. The intermediate baffle 302 can be sized to provide lateral support to at least one battery module 304, such as in the event of regular driving motion, or a collision. The thickness of the intermediate baffle 302 can be selected to provide adequate lateral support. The intermediate baffle 302 can include ribbing and the like to increase stiffness. The intermediate baffle can mechanically secure the at least one battery module against the lower tray. The top cover can mechanically secure the at least one battery module against the lower tray. At least one of the top cover and the intermediate baffle can have a bending stress that is lower than a bending stress of the lower tray.

[0056] The battery module 304 shown is a regular hexahedron, but other shapes are possible. The illustration shows that the intermediate baffle 302 divides a height of the battery module 304 into two portions, such that a lower portion 306 can be cooled with a coolant white the upper portion 308 is maintained coolant-free, or has limited exposure to coolant.

[0057] FIG. 4 shows a top view of an intermediate baffle 402 and staggered hexahedral battery modules 404, according to some examples. FIG. 5 shows a top view of an intermediate baffle 502 and staggered cylindrical battery modules 504, according to some examples. Other shapes, such as hexagons, can be used, to increase the cell density of a battery pack, for example.

[0058] The intermediate baffle can be fastened to one of the top cover and the lower tray with fasteners, or a snap fit. FIG. 6 shows a close up sectional view of a joint, taken along 6 — 6 in FIG. 2. A top cover 102, intermediate baffle 114, and lower tray 108 are shown. The intermediate baffle is countersunk into a relieve in the lower tray. The intermediate baffle can be placed in a recess of the lower tray, and constrained in place with the fastening of the top cover to the lower tray.

[0059] FIG. 7 shows a close-up section view of a joint, according to some examples. A top cover 102’, intermediate baffle 114’, and lower tray 108’ are shown. The intermediate baffle can be sandwiched between the top cover and the lower tray.

[0060] FIG. 8 shows a close-up section view of a joint, according to some examples. A top cover 102”, intermediate baffle 114”, and lower tray 108” are shown. The intermediate baffle and the lower tray can define a continuous lip surface. The top cover can abuts the continuous lip surface. A top cover can abut the lower tray, or be separated by a gasket and the like.

[0061] These and other joints, as is known, may be used to bring together the three layers in a fashion to seal coolant in a battery pack. The joints can be sealed with a compressible rubberized seal, such as an o-ring, adhesives, and the like.

[0062] FIG. 9A shows a side view of a battery pack 900, according to some examples. FIG. 9B shows a top view of the battery pack of FIG. 9A. FIG. 9C shows a perspective view of the battery pack of FIG. 9A, according to some examples. FIG. 9D shows a cross-section of the batery pack of FIG. 9A taken along line 9D - - 9D. An agitator disposed in the coolant reservoir, to agitate the coolant.

[0063] A batery pack housing 902 for an electrical vehicle can include a lower tray 904 that adapted to retain at least one batery module 906. An intermediate baffle 908 can be coupled to the lower tray 904 to define a coolant reservoir 910. The coolant reservoir 910 can be located between the lower tray 904 and the intermediate baffle 908. The intermediate baffle 908 can define a batery module opening 912 adapted to locate a batery module partially below the intermediate baffle 908 and partially above the intermediate baffle 908.

[0064] A seal means, for example seal 914, can be used for sealing the intermediate baffle 908 to the batery module 906, proximal to the batery module 906. The seal means can be for sealing against a flow of coolant out of the coolant reservoir 910.

[0065] A pump 916 can be disposed in the coolant reservoir 910 in fluid communication with a coolant disposed therein. The pump 916 can be coupled to an external heat exchange to pump the coolant to the external heat exchanger.

[0066] FIG. 10 shows a perspective view of a lower tray, according to some examples. A lower tray 1002 can define a plurality of protrusions 1004 extending onto the coolant reservoir such that the batery module abuts at least some of the plurality of protrusions. The protrusions can support the weight of a batery module vertically (Z-axis), while defining a space to be used as a coolant reservoir. The shape of the protrusions can be selected so as to encourage fluid mixing during sloshing.

[0067] FIG. 11 shows a method of cooling a batery pack, according to some examples.

[0068] At 1102, a method of constructing a batery pack for an electrical vehicle can include disposing at least one battery module fixedly in a lower tray.

[0069] At 1104, the method can include covering the lower tray with an intermediate baffle. This can include defining a coolant reservoir located between the lower tray and the intermediate baffle.

[0070] At 1106, the method can include disposing the at least one batery module through a batery module opening of the intermediate baffle partially, and partially in the coolant reservoir. The at least one battery module can be one of a plurality of battery modules. The plurality of battery modules can be arranged in grid pattern. The plurality of battery modules can be staggered.

[0071] Electrical couplings of the at least one battery module can be located above the intermediate baffle. A remainder of the at least one battery module can be disposed below the intermediate baffle in the coolant reservoir.

[0072] At 1108, the method can include sealing the intermediate baffle to the at least one battery module to sealedly retain coolant in the coolant reservoir. The method can include bleeding gas from the coolant reservoir and substantially filling the coolant reservoir with a coolant. The method can include pumping a coolant through the coolant reservoir.

[0073] At 1110, the method can include filling the coolant reservoir partially with the coolant and sloshing the coolant in the coolant reservoir. The coolant reservoir can induce turbulent fluid flow of a coolant disposed in the coolant reservoir with movement of the battery pack. A method can include controlling sloshing by placing one or more auxiliary baffles in the coolant reservoir. Controlling sloshing can include selecting a ratio of gas to coolant in the coolant reservoir. A method can include sloshing the coolant and pumping coolant through the reservoir. Pumping can be controlled by a powertrain control module. A pump can operate when sloshing is not occurring, or is occurring at a rate insufficient to circulate the fluid at a desired rate.

[0075] The term "vehicle" or "vehicular" or other similar term as used herein is inclusive of motor vehicles in general such as passenger automobiles including sports utility vehicles (SUV), buses, trucks, various commercial vehicles, watercraft including a variety of boats and ships, aircraft, and the like, and includes hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). As referred to herein, a hybrid vehicle is a vehicle that has two or more sources of power, for example both gasoline-powered and electric-powered vehicles.

[0076] The term "coupled" is defined as connected, although not necessarily directly, and not necessarily mechanically; two items that are "coupled" can be unitary with each other. The terms "a" and "an" are defined as one or more unless this disclosure explicitly requires otherwise. For example, "an element" has the same meaning as “at least one element," unless the context clearly indicates otherwise. The term “combination” is inclusive of blends, mixtures, alloys, reaction products, and the like. Also, “at least one of’ means that the list is inclusive of each element individually, as well as combinations of two or more elements of the list, and combinations of at least one element of the list with like elements not named. “Or” means “and/or.” The suffix “(s)” as used herein is intended to include both the singular and the plural of the term that it modifies, thereby including one or more of that term (e.g., the film(s) includes one or more films).

Claims

What is claimed is:

1. A method of constructing a battery pack for an electrical vehicle, comprising: locating at least one battery module fixedly in a lower tray; covering the lower tray with an intermediate baffle, defining a coolant reservoir located between the lower tray and the intermediate baffle; locating at least one battery module through a battery module opening of the intermediate baffle partially, with electrical couplings of the at least one battery module located above the intermediate baffle, and a remainder of the at least one battery module located below the intermediate baffle in the coolant reservoir; sealing the intermediate baffle to the at least one battery module to sealedly retain a coolant in the coolant reservoir; filling the coolant reservoir partially with the coolant; and sloshing the coolant in the coolant reservoir.

2. The method of claim 1, comprising bleeding gas from the coolant reservoir and substantially filling the coolant reservoir with the coolant.

3. The method of claim 1, comprising pumping the coolant through the coolant reservoir.

4. The method of claim 1, comprising locating a plurality of foils in the coolant reservoir to induce turbulent fluid flow of the coolant located in the coolant reservoir with movement of the battery pack.

5. The method of claim 3, comprising filling the coolant reservoir partially with the coolant and sloshing the coolant in the coolant reservoir.

6. The method of claim 5, comprising controlling a sloshing of the coolant by placing one or more auxiliary baffles in the coolant reservoir.

7. The method of claim 5, comprising controlling a sloshing of the coolant by selecting a ratio of gas to coolant in the coolant reservoir.

8. A battery pack system for an electrical vehicle, comprising: a lower tray adapted to retain at least one battery module; at least one battery module disposed in the lower tray, the at least one battery module comprising electrical couplings in electrical communication with cells of the at least one battery module; an intermediate baffle coupled to the lower tray defining a coolant reservoir located between the lower tray and the intermediate baffle, the intermediate baffle defining a battery module opening, wherein the at least one battery module is disposed through the battery module opening, with the at least one battery module at least partially disposed in the coolant reservoir, with the electrical couplings extending above the intermediate baffle, opposite the coolant reservoir; a seal coupled between the intermediate baffle and the at least one battery module, the seal configured to retain a coolant in the coolant reservoir; and coolant disposed in the coolant reservoir, partially filling the reservoir such that the coolant is free to slosh within the reservoir.

9. The battery pack system of claim 8, wherein the seal is formed of adhesive.

10. The battery pack system of claim 8, wherein the seal comprises a pre-formed gasket.

11. The battery pack system of claim 8, comprising a top cover coupled to at least one of the lower tray and the intermediate baffle, the top cover sized to extend over the electrical couplings to define an electrical coupling plenum, with the electrical couplings disposed in the electrical coupling plenum.

12. The battery pack system of claim 8, wherein the coolant is disposed in the coolant reservoir.

13. The battery pack system of claim 12, comprising an agitator disposed in the coolant reservoir, to agitate the coolant.

14. The battery pack system of claim 12, wherein the coolant is dielectric.

15. The batery pack system of claim 8, wherein the coolant reservoir is hermetically sealed.