Patent Application
20250115022
The information provided in this section is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.
The present disclosure relates to multi-functional and multi-layered hybrid composite structures.
Vehicles include structural components such as enclosures or other structures that are typically made of metal such as steel or aluminum. In addition to providing structural support functions, the structural components may also need to perform other functions such as thermal insulation, fire resistance, and/or electromagnetic shielding. For example, the structural components may be used when manufacturing an enclosure for a battery pack or electric machine. When the structural components are made using aluminum or steel, the structural components may be relatively heavy.
A multi-layer and multi-functional composite structure includes a structural reinforcing portion configured to provide structural support. The structural reinforcing portion includes reinforcing fibers consolidated in a thermoplastic resin. The thermoplastic resin can be pre-impregnated into the reinforcing fibers and/or supplied during compression molding. A protecting portion is arranged on one side of the structural reinforcing portion and configured to provide at least one of thermal blocking and fire resistance. A shielding portion is arranged on an opposite side of the structural reinforcing portion and configured to shield electromagnetic interference (EMI).
In other features, the structural reinforcing portion and at least one of the protecting portion and the shielding portion are consolidated in the thermoplastic resin in a single step. The structural reinforcing portion, the protecting portion, and the shielding portion are consolidated in the thermoplastic resin in a single step. The protecting portion includes an intumescent material.
In other features, the intumescent material includes an adhesive layer configured to attach the intumescent material to the structural reinforcing portion. The protecting portion includes a mica plate attached to the protecting portion using a binder. The protecting portion includes a fabric, a thermal material, and a fire resistant material. The protecting portion includes a ceramic layer.
In other features, at least one of the protecting portion and the shielding portion comprises a coating. The shielding portion is selected from a group consisting of a metal mesh, a discontinuous fabric, a coated veil, a metal sheet, a perforated metal sheet, and a metal-coated fiber-filled material. The structural reinforcing portion comprises discontinuous fibers selected from a group consisting of chopped fibers, unidirectional tape, nonwoven mat, and directed long fibers. The thermoplastic resin is selected from a group consisting of polyether ether ketone, polyether ketone ketone, polyphenylene sulfide, and polyether imide.
In other features, planar portions of the structural reinforcing portion comprise continuous fibers and non-planar portions of the structural reinforcing portion comprise discontinuous fibers.
A multi-layer and multi-functional composite structure includes a structural reinforcing portion configured to provide structural support and including reinforcing fibers consolidated in a thermoplastic resin. A protecting portion is arranged on one side of the structural reinforcing portion and configured to provide at least one of thermal blocking and fire resistance. A shielding portion is arranged on an opposite side of the structural reinforcing portion and configured to shield electromagnetic interference (EMI). The structural reinforcing portion and at least one of the protecting portion and the shielding portion are consolidated in the thermoplastic resin in a single step.
In other features, the structural reinforcing portion, the protecting portion, and the shielding portion are consolidated in the thermoplastic resin in a single step. The protecting portion is selected from a group consisting of an intumescent material one of consolidated in the thermoplastic resin and attached to the structural reinforcing portion, a mica plate attached to the protecting portion using a binder, a ceramic layer, and a coating layer. The protecting portion includes a fabric, a thermal material, and a fire resistant material. The shielding portion is selected from a group consisting of a metal mesh, a discontinuous fabric, a coated veil, a metal sheet, and a metal-coated fiber-filled material.
In other features, the structural reinforcing portion comprises discontinuous fibers selected from a group consisting of chopped fibers, unidirectional tape, nonwoven mat, and directed long fibers. The thermoplastic resin is selected from a group consisting of polyether ether ketone, polyether ketone ketone, polyphenylene sulfide, and polyether imide. Planar portions of the structural reinforcing portion comprise continuous fibers and non-planar portions of the structural reinforcing portion comprise discontinuous fibers.
Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure.
The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein:
In the drawings, reference numbers may be reused to identify similar and/or identical elements.
While a multi-layered and multi-functional hybrid composite structure is described below in the context of a structural component or enclosure for a vehicle, the multi-layered and multi-functional hybrid composite structures can be used in other applications.
The present disclosure relates to a multi-layered and multi-functional hybrid composite structure (“the hybrid composite structure”) that provides high strength, reduced heat transfer, and/or electromagnetic interference (EMI) shielding. For example, the hybrid composite structure can be used to make an enclosure for a battery pack, an electric machine, or other device to reduce heat transfer and/or EMI to/from the surrounding environment. For example, the hybrid composite structure can be used to prevent thermal runaway propagation (TRP) from one battery cell, module, and/or pack to adjacent battery cells, modules, and/or packs. Enclosures or other structures made using the hybrid composite structure have reduced parts and lower mass (e.g., mass reduction of 40% or greater as compared to enclosures or other structures made of metal).
The hybrid composite structure includes multiple portions or layers supporting different functions and/or incorporating various materials such as an EMI shielding material, thermal barrier materials, flame resistant materials, reinforcing fibers, and/or resin. In some examples, the hybrid composite structure is consolidated in a single process step, such as compression molding using a thermoplastic resin. In other examples, the hybrid composite structure is consolidated in one or more process steps.
In some examples, surface pre-treatment methods can be applied to enhance adhesion between the functional layers such as the EMI shielding layer, thermal insulation layer, and/or fire resistant layer and other layers of the hybrid composite structure. Examples of surface pre-treatment include exposing the material or an adjacent surface to plasma or a flame to heat the surface to improve adhesion to adjacent layers of the hybrid composite structure.
In some examples, an inner portion of the hybrid composite structure includes a thermal insulation layer and/or a flame barrier layer embedded in resin. A middle portion of the hybrid composite structure includes reinforcing fibers embedded in resin. An outer portion of the hybrid composite structure includes an EMI shielding layer embedded in resin. The outer portion faces an outside environment. In some examples, the hybrid composite structure is made using thermoplastic resin. Thermoplastic resin has a greater potential for reclaiming and recycling as compared to thermoset resins.
The hybrid composite structure is multi-functional in that it provides strength and stiffness, TRP protection, and/or EMI shielding. In some examples, the reinforcing fibers include discontinuous fibers, continuous fibers, and/or a combination thereof in different areas of the hybrid composite structure to tailor strength and stiffness where needed.
Referring now to
For example, when battery cells in one or more of the battery modules or the battery pack fail, a thermal runaway event may occur. Thermal runaway events are caused when the temperature of the battery cells, battery module, and/or battery pack increases. The increased temperature releases energy from the battery cells that further increases the temperature of the battery and/or adjacent structures. If not extinguished, the battery cells, battery module, and/or battery pack undergo the thermal runaway event that may cause the temperature of other adjacent battery modules/packs to increase. The increased temperature increases the likelihood of further thermal runaway events (thermal runaway propagation (TRP)).
Referring now to
In some examples, the anode active layers 42 and/or the cathode active layers 24 comprise coatings including one or more active materials, one or more conductive fillers/additives, and/or one or more binder materials. In some examples, the battery cells and/or electrodes are manufactured by applying a slurry to coat the current collectors in a roll-to-roll manufacturing process. In some examples, the cathode current collectors 26 and the anode current collectors 46 comprise foil layers. In some examples, the current collectors are made of one or more materials selected from a group consisting of copper, stainless steel, brass, bronze, zinc, aluminum, and alloys thereof. External tabs 28 and 48 enable external connection to the current collectors and can be arranged on the same side, opposite sides, or different sides.
In
In
Referring now to
In some examples the reinforcing portion 164 is consolidated and then the thermal protecting portion 160 and the shielding portion 168 are attached using adhesive and/or a surface pretreatment step such as heating using plasma or a flame. In some examples, the thermal protecting portion 160 is consolidated with the reinforcing portion 164 in the same consolidation step. In some examples, the reinforcing portion 164 is consolidated with the shielding portion 168 in the same consolidation step. In some examples, the thermal protecting portion 160, the reinforcing portion 164, and the shielding portion 168 are consolidated in the same consolidation step. In other examples, the reinforcing portion 164 is pre-consolidated and one or more additional consolidation steps are performed.
The thermal protecting portion 160 includes one or more layers 180 embedded in resin 184. The thermoplastic resin can be pre-impregnated into the reinforcing fibers and/or supplied during compression molding. In some examples, the one or more layers 180 of the thermal protecting portion 160 include an intumescent material. Examples of fire retardant materials include fabric impregnated with fire retardant such as aluminum tetrahydrate (ATH) and/or ammonium polyphosphate (APP). Additional examples of the fire retardant materials include kaolin, sodium silicate, aluminum hydroxide, magnesium hydroxide, hydrated silica, silicone, titanium dioxide, as well as compounds based on phosphorus, nitrogen, antimony, boron, zinc, or halogens such as bromine and chlorine. A combination of these materials may also be used. In some examples, the protecting portion 160 comprises a ceramic material that is embedded in the resin. In some examples, the protecting portion 160 comprises a rigid plate made of mica.
An example of the intumescent material includes expanding graphite (EG). Additional examples of the intumescent material a combination of materials to create an insulating char, including an acid source, a carbon source, and blowing agent. Acid sources help to initiate the intumescent reaction and can include phosphates that release phosphoric acid when heated, such as ammonium polyphosphate, melamine phosphate, and guanylurea phosphate, which could also act as a carbon source. Compounds that release other acids, such as boric acid, and acidic polymers can also serve as acid sources. Carbon sources provide a carbonaceous char layer and can include expandable graphite, a polyol, such as pentaerythritol and sorbitol, and a carbohydrate, such as starch, cellulose, and dextrin. Blowing agents release gas when heated, causing the intumescent material to form the expanded char layer and can include ammonium polyphosphate, melamine, ammonium bicarbonate, sodium bicarbonate, urea, and azodicarbonamide. When heated above a predetermined temperature, the intumescent material expands and forms a protective char that acts as a barrier to fire. In some examples, the predetermined temperature corresponds to a temperature encountered during a thermal runaway event.
In some examples, the one or more layers 180 include a flexible fabric that is reinforced with thermal material and/or a flame barrier layer. In some examples, the thermal material and/or flame barrier layer experience minimal or no expansion when exposed to high heat or flame. Examples include materials that undergo pyrolysis and form a carbonaceous char or an insulating layer. Examples include cement-based materials, clay, calcium silicate, silica, alumina, zirconia, gypsum, and ceramics.
In some examples, the thermal protecting portion 160 comprises a material that undergoes endothermic reactions to absorb heat. Examples of these materials include ammonium phosphate, hydrated compounds, such as hydrates of aluminum and magnesium, ammonium sulfate, melamine cyanurate, some phosphorous compounds, potassium carbonate. In some examples, the thermal protecting portion 160 maintains electrical insulation properties during exposure to flame. Examples of these materials include silicone-based compounds, phenolic resins, mineral-based compounds, and ceramics
In some examples, the reinforcing layer 164 includes reinforcing fibers 186. including continuous fibers, discontinuous fibers, and/or a mixture of continuous and discontinuous fibers. Suitable reinforcing fibers include carbon fibers (e.g., carbon black, carbon nanotubes, talc, fibers derived from polyacrylonitrile, cellulosic precursors, and/or pitch precursors), glass fibers (e.g., fiber glass, quartz), basalt fibers, aramid fibers, and combinations thereof. In some examples, the continuous fibers are arranged in planar portions of the structure and/or discontinuous fibers are arranged in non-planar or irregular portions of the structure.
In some examples, the EMI shielding layer 188 comprises a woven metal mesh, a continuous or discontinuous flexible fabric, a coated veil, a metal sheet, a perforated metal sheet, or a metal-coated fiber-filled material. For example only, the EMI shielding layer may comprise aluminum foil, copper mesh, nickel mesh, copper and nickel electrolytic coated carbon fiber.
In
For example, one or more layers 192 of the thermal protecting portion 160 are attached by an adhesive layer 193 to one side of the reinforcing portion 164. In some examples, the one or more layers 192 include a thermal insulating layer and/or a flamer barrier layer. In some examples, the reinforcing layer 164 includes reinforcing fibers 186. In some examples, the reinforcing fibers 186 include continuous fibers, discontinuous fibers, and/or a mixture of continuous and discontinuous fibers. The shielding layer 168 includes an electromagnetic interference (EMI) shielding layer 193 attached by adhesive 194 (and/or surface treatment) to the reinforcing portion 164.
In
In some examples, the EMI shielding layer 188 comprises a coating layer 198 that is applied in a liquid form and optionally cured as described above. In some examples, the EMI shielding layer includes a coating including conductive particles (e.g., copper, aluminum, silver, nickel, gold, tin, or graphene). In other examples, the shielding layer is applied using a metal plating process.
In some examples, the hybrid composite structure is able to withstand a flame of 950° C. for 5 minutes while limiting temperature on the opposite side of the hybrid composite structure to a temperature less than 370° C.
In some examples, the hybrid composite structure includes discontinuous carbon fiber in a thermoplastic polymer matrix. In some examples, the discontinuous carbon fiber comprises unidirectional tape, nonwoven mat, and/or directed long fiber technologies used with compression molding or stamp forming. In some examples, the hybrid composite structure includes chopped carbon fiber fillers and a polymer matrix including a thermoplastic polymer selected from a group consisting of polyether ether ketone (PEEK), polyether ketone ketone (PEKK), polyphenylene sulfide (PPS), polyether imide (PEI), and combinations thereof.
In some examples, the hybrid composite structure includes continuous fibers in flat regions and discontinuous fibers in regions of non-planar geometric features, such as a channel, ribs, stiffener, and/or hat sections. In some examples, the hybrid composite structure is produced in a single consolidation step using a compression molding process.
Referring now to
In
In
The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure.
Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”
In the figures, the direction of an arrow, as indicated by the arrowhead, generally demonstrates the flow of information (such as data or instructions) that is of interest to the illustration. For example, when element A and element B exchange a variety of information but information transmitted from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no other information is transmitted from element B to element A. Further, for information sent from element A to element B, element B may send requests for, or receipt acknowledgements of, the information to element A.
