Refractory enclosure for batteries and inverters and batteries and inverters incorporating refractory enclosure

Abstract

A battery cell, battery module, battery pack or wrapped inverter has a housing with a refractory body. The refractory body includes a thermoplastic substrate optionally free of a flame retardant and having an inner surface and an opposing outer surface, and a nickel layer having a thickness of 10 to 60 microns electroplated on at least a portion of the inner surface or both of the inner and outer surfaces of the thermoplastic substrate. The thermoplastic substrate has an electroplatable layer formed from an electroplatable composition, the electroplatable composition contains acrylonitrile-butadiene-styrene, polycarbonate, polyetherimide, polysulfone, polyphenyl ether, polyarylether, polytetrafluoroethylene, diallyl phthalate, polyacetal, polyethersulfone, urea formaldehyde, phenolic plastic, a blend of acrylonitrile-butadiene-styrene and polyester, and an acid functionalized polyethylene copolymer or an ionomer thereof. At least one of an acid-functionalized polypropylene copolymer or ionomer thereof, or an acid-functionalized polyamide copolymer or ionomer thereof.

Description

Technical Field

[0001] The present disclosure relates to refractory articles, in particular refractory articles that can be used as housings or components of housings for batteries and inverters. The present disclosure also relates to batteries or inverters that include the refractory articles. Background Art

[0002] A battery pack typically has a housing and several battery modules housed in the housing, and the battery module may include a plurality of battery cells connected in series, in parallel, or in a combination of the two. The battery pack may be configured to deliver a desired voltage, capacity, or power density, and is therefore useful in a wide variety of applications. However, the battery pack may be prone to thermal runaway due to short circuits, improper use such as overcharging, or exposure to extreme external temperatures or mechanical loads.

[0003] Batteries operate through oxidation and reduction reactions. When the reaction rate in a battery cell increases to the point where more heat is generated than can be removed, thermal runaway can occur, leading to further increases in both the reaction rate and heat generation. Eventually, the heat generated is great enough to cause gassing or combustion of the battery cell.

[0004] During thermal runaway, a large amount of thermal energy can be released quickly, heating the entire cell to temperatures above 850°C. Due to the increased temperature of the cell experiencing thermal runaway, the temperature of neighboring cells within the battery pack will also increase. If the temperature of these neighboring cells is allowed to increase without any control, they may also enter a thermal runaway state, resulting in a cascading effect where the onset of thermal runaway within a single cell propagates throughout the entire battery pack.

[0005] Many approaches have been proposed to manage thermal runaway in batteries. Despite extensive research, there remains a continuing need for refractory articles that can be used in batteries or other electronic devices to reduce the risk of thermal runaway. Summary of the invention

[0006] The device includes a housing having a fire-resistant body, wherein the device is a battery cell, a battery module, a battery pack or a wrapped inverter, and the fire-resistant body includes a thermoplastic substrate that is optionally free of flame retardants, and the thermoplastic substrate has an electroplatable layer formed from an electroplatable composition, wherein the electroplatable composition contains acrylonitrile-butadiene-styrene, polycarbonate, polyetherimide, polysulfone, polyphenylene oxide, polyarylether, polytetrafluoroethylene, diallyl phthalate, polyacetal, polyethersulfone, urea formaldehyde, phenolic plastic, acrylonitrile- The invention relates to a thermoplastic substrate comprising at least one of a blend of butadiene-styrene and polyester, an acid-functionalized polyethylene copolymer or ionomer thereof, an acid-functionalized polypropylene copolymer or ionomer thereof, or an acid-functionalized polyamide copolymer or ionomer thereof, the thermoplastic substrate having an inner surface and an opposite outer surface; a nickel layer electroplated on at least a portion of the inner surface of the thermoplastic substrate or at least a portion of both the inner surface and the outer surface, the nickel layer having a thickness of 10 to 60 microns, preferably 15 to 50 microns, and more preferably 20 to 45 microns.

[0007] In one aspect, the device is a battery cell comprising: a housing as described above; an electrolyte enclosed within the housing and facing the inner surface of the thermoplastic substrate; an anode and a cathode each in contact with the electrolyte; a separator separating the anode from the cathode; and a first terminal and a second terminal electrically coupled to the anode and the cathode, respectively, and extending outward from the housing.

[0008] The battery module comprises a plurality of electrically connected battery cells, wherein at least one of the battery cells is the battery cell described above.

[0009] In another aspect, the device is a battery module comprising a housing as described above and a plurality of electrically connected battery cells disposed in the housing and facing the inner surface of the thermoplastic substrate.

[0010] The battery pack includes a plurality of electrically connected battery modules, wherein at least one of the battery modules is the battery module described above.

[0011] In yet another aspect, the device is a battery pack, which includes the housing as described above and a plurality of battery modules arranged in the housing and facing the inner surface of the thermoplastic substrate.

[0012] In yet another aspect, the device is a packaged inverter having a housing as described above; and an inverter disposed within the housing and facing the inner surface of the thermoplastic substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The following description should not be considered limiting in any way. Referring to the drawings, like elements have like reference numerals:

[0014] Figure 1 is a cross-sectional view of a portion of an exemplary first resistant article;

[0015] Figure 2 An exemplary refractory article during thermal runaway is shown;

[0016] Figure 3 is a perspective side view of an exemplary battery cell housing;

[0017] Figure 4 is a partial cutaway perspective view of an exemplary battery cell having a fire resistant housing;

[0018] Figure 5 is a schematic diagram of an exemplary battery module having a fire-resistant housing;

[0019] Figure 6 is a schematic diagram of an exploded structure of an exemplary battery pack having a fire-resistant housing;

[0020] Fig. 7A and Figure 7B shows the nickel plated sample after the sample has been exposed to a continuous flame for 2.2 minutes, where Fig. 7A shows the front side exposed to the flame, and Figure 7B The rear side not exposed to the flame is shown; and

[0021] Figure 8 The electromagnetic shielding effectiveness measured for the electroplated samples of Example 2 as a function of frequency is plotted. DETAILED DESCRIPTION

[0022] The present inventors have discovered articles that exhibit low heat absorptivity and high heat reflectivity. These properties improve the thermal insulation of the articles and increase the flame retardancy or heat resistance of the articles, allowing them to be used as thermal management barriers.

[0023] In addition, the article can have a hard surface that can withstand high energy impacts, such as particle impacts. During a thermal runaway event, the battery cell ejects particles that can damage materials / structures near the battery cell. The article as disclosed herein has the ability to withstand particle impacts, and thus can minimize the impact caused by the ejected particles.

[0024] The article also allows for ferromagnetic dissipation of low frequency electromagnetic emissions (EMI) and can provide EMI shielding at low frequencies. This is advantageous because the metal oxide semiconductor field effect transistors (MOSFETs) of the inverter generate low frequency electromagnetic emissions in the range of 30kHz-1.5MHz, and these emissions require ferromagnetic shielding on both the inverter and the battery cover to avoid undesirable effects on the 12V line.

[0025] Ceramic coatings have been considered to manage flammability and wear. However, these layers are difficult to apply and are not conductive, so they do not reduce electromagnetic interference.

[0026] Aluminum foil is widely used for EMI management, but it is only useful in the high-frequency region (above 1MHz) because aluminum is paramagnetic and is not effective in shielding low-frequency emissions.

[0027] One alternative is steel, but the material is heavy, thermally and electrically conductive, and could expose people to the high voltages of the battery system if not handled properly.

[0028] The articles described herein avoid the problems associated with articles having ceramic coatings, aluminum foil or steel, and can be used as housings or components of inverters and batteries to shield heat / flame and electromagnetic interference, as well as to control particle impacts.

[0029] The article (also referred to as a "refractory article") includes a thermoplastic substrate having an inner surface and an opposing outer surface; and a nickel layer electroplated on at least a portion of the inner surface or at least a portion of both the inner surface and the outer surface of the thermoplastic substrate.

[0030] The refractory product may be a housing or a component of an inverter or a battery, such as a battery cell, a battery module, a battery pack, or a combination thereof. The component of the housing may include a body of the housing or a cover of the housing. The shape of the refractory product is not particularly limited as long as they can form a housing to accommodate a battery or an inverter.

[0031] When the refractory product is a housing or a component of a battery or inverter, the inner surface means the surface facing the battery or inverter. Preferably, the nickel layer is electroplated on at least a portion of the inner surface of the refractory product or the inner surface and at least a portion of the opposite outer surface of the refractory product. The presence of the nickel layer can contribute to EMI shielding, thermal insulation and flame retardancy at low frequencies.

[0032] Thermoplastic substrates include an electroplatable layer formed by an electroplatable composition, the electroplatable composition comprising acrylonitrile-butadiene-styrene (ABS), polycarbonate, polyetherimide, polysulfone, polyphenylene oxide, polyarylether, polytetrafluoroethylene, diallyl phthalate, polyacetal, polyethersulfone, urea formaldehyde, phenolic plastics, or a blend of ABS and polyester such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT) or a combination thereof, an acid-functionalized polyethylene copolymer or an ionomer thereof, an acid-functionalized polypropylene copolymer or an ionomer thereof, or at least one of an acid-functionalized polyamide copolymer or an ionomer thereof. The acid-functionalized polyethylene or polypropylene copolymer may include ethylene or propylene units and acid-functionalized olefin monomers such as 3-butenoic acid, 4-pentenoic acid, 10-undecenoic acid or a combination thereof. The acid-functionalized ethylene or propylene may also include a copolymer of ethylene and acrylic acid or a copolymer of propylene and acrylic acid. For example, electroplating composition can comprise the acid-modified polypropylene of the unit derived from acrylic acid and 97-88 % by weight, 95-88 % by weight, 93-90 % by weight or 92 % by weight containing 3-12 % by weight, 5-12 % by weight, 7 to 10 % by weight or 9 % by weight. Acid-functionalized ethylene or propylene copolymer can optionally comprise the other olefin unit derived from propylene, ethylene, 1-butylene, 3-methyl-1-butylene, 1-pentene, 4-methyl-1-pentene, 1-hexene, vinyl cyclohexane or its combination. In addition, acid-functionalized polyethylene or polypropylene copolymer can be processed with salt such as metal salt or ammonium salt to form an ionomer with the ionic bond derived from the acid functional group.

[0033] These polymers or polymer blends may be present in an amount of 50 weight percent to 99 weight percent, or 60 to 99 weight percent, 70 to 99 weight percent, or 80 to 99 weight percent based on the total weight of the electroplatable composition.

[0034] Preferably, the electroplatable layer is an ABS layer formed by an ABS composition having a butadiene content of 5 to 30 weight percent based on the total weight of the ABS composition. The butadiene content can be adjusted by adjusting the amount of ABS in the ABS composition and the percentage of butadiene units in the ABS polymer. The ABS composition may include only ABS as a polymer component. Alternatively, the ABS composition may include a blend of ABS and polycarbonate, or a blend of ABS and polyester such as PET, PBT or a combination thereof. The ABS composition may include 30 to 75 weight percent of polycarbonate or polyester based on the total weight of the ABS composition. The weight ratio of polycarbonate or polyester relative to ABS may be 1:5 to 5:1 or 2:5 to 4:1.

[0035] Electroplating compositions such as ABS compositions can additionally include various additives, provided that the additives are selected without negatively affecting the desired properties of the substrate, particularly rigidity, impact resistance, insulating properties and wear resistance and strain resistance. Such additives can be mixed at the appropriate time during the mixing of the components of the electroplating compositions. The example of additives includes impact modifiers, fillers, reinforcing agents, antioxidants, heat stabilizers, light stabilizers, ultraviolet (UV) light stabilizers, plasticizers, lubricants, mold release agents, antistatic agents, colorants (such as carbon black and organic dyes), surface effect additives, radiation stabilizers (such as infrared absorption) and anti-dripping agents. A combination of additives can be used. The total amount of additives (except any impact modifier, filler or reinforcing agent) can be 0.001 weight percent to 5 weight percent based on the gross weight of the electroplating composition. In one embodiment, the electroplating composition includes at least one of reinforcing fillers, flow promoters, antioxidants or mold release agents.

[0036] Advantageously, thermoplastic substrates and electroplatable compositions can be free of flame retardants. Due to the high reflectivity of nickel-plated products, even when the thermoplastic substrate does not contain a flame retardant, the thermoplastic substrate can also withstand two minutes of flame exposure. Therefore, the nickel plating of thermoplastics provides an alternative to using an intumescent formulation, and the flame retardant ability in non-flame-retardant materials (prerequisite is surface nickel plating) and flame retardant materials. This is advantageous because in some cases, the flame retardant may leach into the electroplating bath that affects electroplating, and the expansion additive can limit the thermal load on the nickel-plated thermoplastic product. In view of the high cost of flame retardants and expansion additives, the refractory products free of flame retardants and expansion additives can have economic advantages. In addition, the thermoplastics in such products can be circulated without worrying about the flame retardant additive.

[0037] The electroplatable composition can be formed into useful shaped articles by various methods such as injection molding, extrusion, rotational molding, blow molding, and thermoforming to form a thermoplastic substrate.

[0038] The thermoplastic substrate may include only one layer, such as an electroplatable layer formed from an electroplatable composition. The thermoplastic substrate may also include two or more layers, such as an electroplatable ABS layer and a polycarbonate layer dispersed in the ABS layer.

[0039] The thermoplastic substrate may have a thickness of 1.5 to 6 millimeters (mm), preferably 2.5 to 5 mm, more preferably 2.5 to 3.5 mm. The nickel layer may have a thickness of 10 to 60 micrometers, preferably 15 to 50 micrometers, more preferably 20 to 45 micrometers. The thickness of the nickel layer relative to the thickness of the thermoplastic substrate is 1:100 to 1:500, preferably 1:100 to 1:400, and more preferably 1:100 to 1:250 or 1:100 to 1:200.

[0040] The nickel layer can include only one layer or two or more, for example, a combination of two to five, two to four, or two to three different sublayers. The combination of different sublayers can provide corrosion resistance, ensuring good adhesion and thermal cycle performance. Preferably, the nickel layer has at least two layers, a semi-bright nickel layer (for example, a semi-bright nickel layer without sulfur) and a bright nickel layer. The bright nickel layer can be arranged on the semi-bright nickel layer, and the semi-bright nickel layer can be a layer adjacent to the thermoplastic substrate. The semi-bright nickel layer can have a thickness of 4 to 40 microns, 10 to 40 microns, or 15 to 30 microns. The bright nickel layer can have a thickness of 5 to 40 microns, 5 to 20 microns, or 5 to 15 microns.

[0041] The refractory article may additionally include a copper layer disposed between the thermoplastic substrate and the nickel layer. When present, the copper layer may be electroplated directly onto the thermoplastic substrate, and then the nickel layer, such as a semi-bright nickel layer, may be electroplated onto the copper layer. The thickness of the copper layer may be 10 to 40 microns, preferably 10 to 35 microns, more preferably 10 to 30 microns. The copper layer may promote thermal insulation and flame retardancy.

[0042] The refractory product may further comprise palladium between the thermoplastic substrate and the copper layer or, if no copper layer is present, between the thermoplastic substrate and the nickel layer. The presence of palladium allows the copper layer or the nickel layer to be electroplated on the thermoplastic substrate.

[0043] Optionally, the refractory product further comprises a chromium layer disposed on the nickel layer. The nickel layer has a first surface facing the thermoplastic substrate and an opposite second surface. Preferably, the chromium layer is disposed on the second surface of the nickel layer. The chromium layer can have a thickness of 0.1 to 10 microns, preferably 0.1 to 5 microns, more preferably 0.1 to 1 micron. The presence of the chromium layer improves the hardness of the refractory product and helps the product withstand particle impact. The presence of the chromium layer can also reflect visible and infrared light, thereby reducing the thermal load on the thermoplastic substrate.

[0044] The refractory article may have an electromagnetic shielding effectiveness greater than 30 decibels (dB), eg, 40 to 60 dB or 45 to 60 dB, at 30 megahertz (MHz) to 15 gigahertz (GHz) as determined by ASTM D4935.

[0045] To produce refractory products, the thermoplastic substrate can be pretreated to remove contaminants such as grease, dirt, and debris from the surface to be plated. Surfactants, alkaline cleaners, or other suitable cleaners known in the art can be used. As a specific example, a water bath with soap is used to facilitate dust removal from the thermoplastic substrate.

[0046] The cleaned thermoplastic substrate can then undergo an etching process to roughen or functionalize the surface to be plated so that an effective bond between the substrate and the copper layer or nickel layer can be provided. For example, an etching solution is applied to the thermoplastic substrate, and the etchant in the etching solution can react chemically with the surface of the thermoplastic substrate, introducing microscopic pores or voids, which can serve as a site for catalyst absorption during subsequent steps. The etchant can include chromic acid, chromium trioxide or sulfuric acid solution. Wetting agents can also be used to help wet the surface during the etching operation. In one embodiment, chromic acid can oxidize butadiene on the surface of the thermoplastic substrate to be plated, which produces a structure for mechanical bonding sites.

[0047] After etching, excess etchant may be removed, for example, by rinsing. Application of a neutralizing agent may additionally ensure complete elimination of any excess etchant. During neutralization, if hexavalent chromium is used, it may be converted to trivalent chromium. If hexavalent chromium is allowed to contact the activated surface, it may interfere with the subsequent activation process. Hexavalent chromium contamination may also result in uneven plating of areas of a part if not removed. Neutralizing agents may include complexing agents such as polyamines, and reducing agents such as hydroxylamine and bisulfites, or any other suitable neutralizing agent known in the art for removing etchants.

[0048] The etched surface can then be treated with an activator to form a catalytically active surface for subsequent electroless metal plating. The activator can be a low concentration noble metal liquid activator that acts as a catalyst during electroplating. The noble metal found in the activator can include at least one of palladium, platinum or gold. Palladium is preferred.

[0049] The colloid system can be used to activate the etched surface. For example, a solution of colloidal palladium is usually used, and colloidal palladium can be formed by the reaction of palladium chloride and stannous chloride in the presence of excess hydrochloric acid (Annual Book of ASTM Standard, Vol. 02.05, "Metallic and Inorganic Coatings; Metal Powders, Sintered P / M Structural Parts", Name: B727-83, Standard Practice for Preparation of Plastic Materials for Electroplating, 1995, 446-450 pages). During activation, palladium particles can be attached to the etched surface, such as absorbed in the holes or voids of the etched surface of the thermoplastic substrate. Subsequently, an acid bath such as HBF4 bath can be used to chemically remove tin from the outside of the activator colloid, exposing palladium for subsequent chemical plating.

[0050] The activated thermoplastic substrate can then be placed in an electroless plating bath to deposit a copper or nickel layer to render the surface of the thermoplastic substrate conductive. Electroless plating on the thermoplastic substrate can include full plating or selective plating. For the former, copper or nickel is deposited on the entire surface of the thermoplastic substrate, such as both the inner and outer surfaces of the thermoplastic substrate. Selective plating includes depositing the metal onto a specific surface of the thermoplastic substrate, such as only on the inner surface of the substrate or only on the outer surface of the substrate.

[0051] If selective plating is desired, portions of the thermoplastic substrate that are not to be plated can be masked and then the plating catalyst sprayed only onto the areas that are to be plated. The catalyzed substrate is then loaded into a plating fixture and immersed in an electroless plating tank to deposit copper or zinc plating on the designated areas. Other known selective plating methods can also be used.

[0052] After electroless plating, copper or zinc may optionally be deposited from a copper strike bath or zinc strike bath over the thin zinc or copper layer electroplated with electroless plating to improve conductivity, allowing the thermoplastic substrate to be further processed without causing plating defects due to the increasingly high voltages required for subsequent electroplating. This step is an initial electrolytic (current-carrying) plating that is run at very low amperages in order to increase the plating thickness. The electroplated copper or zinc layer may be 0.1 to 3 microns thick, depending on the materials used.

[0053] Subsequently, a copper layer may be deposited to increase leveling ductility. During this step, copper is deposited at a relatively high current in a copper bath, such as a copper acid bath containing copper ions and acid. This layer of copper can level the microscopically rough surface created in the etching step and provide the electroplated part with its leveling and brightness. The thickness of the copper layer can vary from 10 to 40 microns, depending on the amount of ductility and leveling required for the application.

[0054] A bath consisting of hydrogen peroxide and sulfuric acid can be used to remove the organic brightener film left on the thermoplastic substrate after copper electroplating. This can promote adhesion between the copper layer and the nickel layer electroplated in the next bath. Without this step, there may be a lack of adhesion between the metal layers, resulting in delamination.

[0055] The thermoplastic substrate can then be immersed in a nickel plating bath. An electric current is applied to the thermoplastic substrate, which causes the nickel particles to adhere and bond to the surface of the copper layer on the thermoplastic substrate, forming a nickel layer.

[0056] The nickel layer may comprise only one layer or two or more layers, for example a combination of two to five, or two to four, or two to three different sub-layers. In one embodiment, the nickel layer comprises at least one of a semi-bright nickel layer, a high sulfur nickel layer, a bright nickel layer or a porous nickel layer.

[0057] The semi-bright nickel layer may be free of sulfur and is very inert (non-reactive) in nature, which greatly contributes to the ultimate corrosion protection of the thermoplastic substrate. The semi-bright nickel layer may also promote adhesion and improve EMI shielding performance. The grain structure of the semi-bright nickel deposit is generally columnar and nickel may be deposited from a semi-bright nickel solution. Additives for semi-bright nickel solutions are known and have been described, for example, in the Nickel Plating Handbook 2014 of the Nickel Research Institute. The layer may have a thickness of 4 to 40 microns.

[0058] The nickel layer may include a high sulfur nickel layer. This layer may be a sacrificial high sulfur nickel layer to provide small sites for corrosion to prevent corrosion in large sites. The high sulfur nickel layer may have a thickness of 1 to 2 microns. It may be deposited between sulfur-free semi-bright and bright nickel layers. If used, this layer may produce significant improvements in corrosion protection because it is a very active deposit that may be sacrificially corroded during use. The electrolyte used to deposit the high sulfur nickel layer may be a Watt-type nickel plating bath or a semi-bright nickel bath, but also contains thiazole and / or thiazoline additive compounds or other known suitable sulfur-containing compounds in appropriate amounts to achieve the desired sulfur content in the high sulfur nickel layer.

[0059] The nickel layer may include a bright nickel layer. This layer adds shine, gloss and corrosion protection. Bright nickel deposits restore the brightness of the thermoplastic substrate after semi-bright nickel plating. The primary brightener may include saccharin, which provides sulfur to co-deposit with the nickel. Bright nickel thickness may range from 5 to 40 microns, depending on the environment in which the application is located. Bright nickel baths are known and have been described, for example, in the Nickel Plating Handbook 2014 of the Nickel Research Institute. Satin nickel is another option to replace bright nickel. Satin nickel deposits achieve satin color and reflectivity by controlling the amount of organic additives added to the bath.

[0060] The nickel layer may also include a porous nickel (Dur-Ni) layer. The layer may have a thickness of 1 to 3 microns. The electroplating bath for the porous nickel layer may inertize the particles encapsulated in the nickel layer during electroplating. The particles may provide high microporosity in the subsequent chromium layer. In one embodiment, the porosity is greater than or equal to 64,000 pores / square inch surface area, such as 64,000 pores / square inch to 150,000 pores / square inch.

[0061] Optionally, a chromium layer is electroplated on the nickel layer. Rapid chromium plating can be used and the process conditions are known to those skilled in the art.

[0062] Prior to chromate plating, the porous nickel surface can be activated with a small amount of current in a nickel activator bath (e.g., an acid solution) so that it will accept chrome plating. If not properly activated, low current density areas of the thermoplastic substrate may not accept chrome coverage.

[0063] Chrome plating can provide a hardened, corrosion resistant and reflective chrome surface. Chrome will only adhere where nickel is present and if a Dur-Ni layer is used, the chrome can be plated around microscopic inert particles contained in the Dur-Ni layer, leaving a microporous surface.

[0064] Figure 1 is a cross-sectional view of a portion of an exemplary refractory product. Figure 1 As shown in FIG, a refractory product 1 includes a thermoplastic substrate 2, a copper layer 3 electroplated on the inner surface of the thermoplastic substrate, and a nickel layer 4 electroplated on the copper layer. The refractory product 1 also includes a chromium layer 5 disposed on the nickel layer. The copper, nickel and chromium layers may also be electroplated on the outer surface of the thermoplastic substrate (not shown).

[0065] The refractory articles described herein have excellent flame retardancy and are able to withstand at least 2 minutes when exposed to a 700°C or 800°C flame. Figure 2 As shown in , the refractory product 70 can deflect heat so that when the inner surface 71 is subjected to a 700° C. or 800° C. flame, its surface temperature T1 can be about 400° C., and the opposite surface 72 can have a temperature T2 of less than 120° C. The refractory product can be used as a housing or a component of an inverter and a battery (including a battery cell, a battery module, a battery pack, or a combination thereof).

[0066] refer to Figure 3 In other embodiments, the battery cell housing may include a body 11, a top cover 12, and a bottom cover 15, wherein the body 11, the top cover 12, the bottom cover 15, or a combination thereof may be a refractory product as described herein. Preferably, at least the body 11 is a refractory product. The terminal 18 for the battery cell 10 may extend from the inside of the body 11 through the top cover 12. The body 11, the top cover 12, and the bottom cover 15 may be assembled together using mechanical and / or chemical methods such as fasteners, adhesives, or welding (e.g., laser welding). Other known techniques may also be used. The bottom cover 15 and the body 11 may be a one piece structure, and in this case, the housing of the battery cell 10 includes only the top cover and the body.

[0067] A battery cell having a housing including a refractory product such as a refractory body is also disclosed. The battery cell includes a housing, an electrolyte facing the inner surface of the thermoplastic substrate, a positive electrode (cathode), a negative electrode (anode), and a separator disposed between the anode and the cathode. The materials and constructions for the electrolyte, electrodes, and separator (if applicable) are known and are not particularly limited. The battery cell may be a cylindrical cell, a prismatic cell, or a pouch cell. Reference Figure 4, an example of a battery cell 20 includes a housing 22, a cathode 28, an anode 21, and a separator 27 disposed between the cathode 28 and the anode 21. The battery cell 20 also includes an insulator 26, a cathode sheet or terminal 24, and an anode sheet or terminal 23. An electrolyte 25 may be disposed within the housing 22.

[0068] The battery cell may be used for a lithium ion battery, such as a lithium iron phosphate battery, a ternary lithium battery, a solid-state lithium ion battery, etc. As used herein, a lithium ion battery includes a rechargeable lithium ion battery.

[0069] More than one battery cell may be used.Thus, a battery module is also disclosed that includes a plurality of battery cells that are electrically connected, such as in series, or in parallel, or a combination thereof.

[0070] See also Figure 5 The battery module 30 may include a plurality of battery cells 35 facing the inner surface of the thermoplastic substrate and a housing enclosing the battery cells. The housing may include a body 32 and a cover 38. The body 32, the cover 38, the housing of the battery cells 35, or a combination thereof may independently include a refractory product as described herein. Preferably, at least the body 32 is a refractory product.

[0071] Battery modules can be assembled together to form a battery pack. Figure 6 The battery pack 60 may have a housing including a body 66 and a cover 62, and a battery module 65 enclosed in the housing and facing the inner surface of the thermoplastic substrate. The body 66, the cover 60, the housing of the battery pack 65, the housing of the battery cell, or a combination thereof may independently include a fire-resistant article as described herein. The battery module may be electrically connected in the battery pack.

[0072] The battery cells, battery modules, and battery packs may be used in electric vehicles, hybrid vehicles, plug-in hybrid vehicles, consumer electronics, or other products that use batteries.

[0073] As described herein, the refractory product can also be used as a housing or a component thereof for an inverter. The wrapped inverter can therefore have a housing including a refractory product (refractory body) as described herein; and an inverter arranged in the housing and facing the inner surface of the thermoplastic substrate.

[0074] The above described and other features are exemplified by the following embodiments.

[0075] Example

[0076] Example 1

[0077] The materials used in this example are described in Table 1. The materials were commercial grade and did not have any additives to improve flame retardancy or to achieve high temperature performance.

[0078] Table 1.

[0079]

[0080] The thermoplastic composition was molded under the conditions shown in Table 2 to form a thermoplastic substrate.

[0081] Table 2.

[0082] describe unit condition Pre-drying temperature ℃ 100-150 Pre-drying time Hour 3-4 1 stage temperature ℃ 255-280 2 temperature levels ℃ 255-290 3 temperature levels ℃ 255-290 Nozzle temperature ℃ 260-290 Molding temperature (melt) ℃ 260-290 Molding temperature (mold) ℃ 40-70

[0083] Several 6×6 inch square plates were formed using the thermoplastic composition. These plates were subjected to an electroless plating process including chromic acid etching followed by Pd deposition, electroless copper and nickel deposition. The process was optimized using smaller 3×4 inch square coupons to achieve a plating thickness of 20 microns.

[0084] The flammability test was performed using a propane torch with a maximum temperature of 1500°C and a vertical sample holder placed at a fixed distance from the torch. The gas flow was throttled until a reading of over 1000°C was measured using a K-type thermocouple at 3 inches from the tip of the torch. A 1 mm thick steel plate was slid into the sample holder and the temperature on its surface was measured using an infrared camera. After confirming the ability to exceed 850°C in 1 minute, the steel plate was replaced with an electroplated sample and kept under continuous flame exposure for 2.2 minutes. The torch was turned off after 2.2 minutes.

[0085] like Fig. 7A As shown in the graph, a circular pattern is formed on the nickel layer and it bulges out due to thermal expansion. Due to the ability of the electroplated layer to reflect radiant heat, it also exhibits a lower peak surface temperature than steel (about 400°C). Throughout the test, the back side showed a much lower temperature (<120°C). The edge of the electroplated sample cracked, exposing the underlying material to the flame and catching fire. After turning off the torch, the fire was completely extinguished. The sample retained its original geometry and rigidity after being removed from the sample holder, as shown in the graph. Figure 7B Inspection showed that both the front and back layers were intact with no surface cracks developing in the nickel layer.

[0086] Example 2

[0087] The thermoplastic composition of Table 1 was used to form a plate under the conditions shown in Table 2. These plates were subjected to an electroless plating process including chromic acid etching, followed by Pd deposition, electroless copper and nickel deposition, and chromium deposition. The copper layer, nickel layer, and chromium layer had thicknesses of 15 microns, 30 microns, and 0.25 microns, respectively.

[0088] Electromagnetic shielding effectiveness was measured at 30 kHz to 15 GHz according to ASTM D4935. The shielding effectiveness results are shown in Figure 8 The results show that the plated samples have excellent electromagnetic shielding efficiency of 40 to 60 decibels (dB) or 45 to 60 dB at 30 megahertz (MHz) to 15 gigahertz (GHz) as measured by ASTM D4935.

[0089] The electroplated samples of Example 2 were subjected to flammability testing according to the procedure of Example 1, with a temperature of 1200°C and a test duration of 5 minutes. The results showed that the plated layer could withstand a 1200°C fire and protect the underlying material (thermoplastic substrate).

[0090] All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term in the present application contradicts or conflicts with a term in the incorporated reference, the term from the present application takes precedence over the conflicting term from the incorporated reference.

[0091] Although typical embodiments have been described for the purpose of illustration, the foregoing description should not be considered as limiting the scope of this document. Therefore, various modifications, variations and substitutions may occur to those skilled in the art without departing from the spirit and scope of this document.

Claims

1. An apparatus comprising a housing having a refractory body, The device is a battery cell, a battery module, a battery pack or a packaged inverter, and The refractory body comprises: a thermoplastic substrate, optionally free of flame retardants, comprising an electroplatable layer formed from an electroplatable composition comprising at least one of acrylonitrile-butadiene-styrene, polycarbonate, polyetherimide, polysulfone, polyphenylene oxide, polyarylether, polytetrafluoroethylene, diallyl phthalate, polyacetal, polyethersulfone, urea formaldehyde, phenolic plastic, a blend of acrylonitrile-butadiene-styrene and a polyester, an acid-functionalized polyethylene copolymer or ionomer thereof, an acid-functionalized polypropylene copolymer or ionomer thereof, or an acid-functionalized polyamide copolymer or ionomer thereof; and A nickel layer electroplated on at least a portion of the inner surface or at least a portion of both the inner surface and the outer surface of the thermoplastic substrate has a thickness of 10 to 60 microns, preferably 15 to 25 microns, more preferably 20 to 45 microns.

2. The apparatus of claim 1, wherein the electroplatable layer is an acrylonitrile-butadiene-styrene layer formed from an acrylonitrile-butadiene-styrene composition having a butadiene content of 5 to 30 weight percent based on the total weight of the acrylonitrile-butadiene-styrene composition.

3. The apparatus of claim 2, wherein the acrylonitrile-butadiene-styrene composition further comprises 30 to 75 weight percent of a polycarbonate or a polyester based on the total weight of the acrylonitrile-butadiene-styrene composition.

4. The apparatus according to any one of claims 2 to 3, wherein the thermoplastic substrate further comprises a polycarbonate layer disposed on the acrylonitrile-butadiene-styrene layer.

5. The apparatus according to any one of claims 1 to 4, wherein the thermoplastic substrate has a thickness of 1.5 to 6 mm, preferably 2.5 to 5 mm, more preferably 2.5 to 3.5 mm.

6. The apparatus according to any one of claims 1 to 5, wherein the refractory body further comprises a copper layer arranged between the thermoplastic substrate and the nickel layer.

7. The device according to claim 6, wherein the copper layer has a thickness of 10 to 40 micrometers, preferably 10 to 35 micrometers, more preferably 10 to 30 micrometers.

8. The apparatus of any one of claims 1 to 7, wherein the nickel layer has a first surface facing the thermoplastic substrate and an opposing second surface, and the refractory body of the housing further comprises a chromium layer disposed on at least a portion of the second surface of the nickel layer.

9. The device according to claim 8, wherein the chromium layer has a thickness of 0.1 to 10 micrometers, preferably 0.1 to 5 micrometers, more preferably 0.1 to 1 micrometer.

10. The device according to any one of claims 1 to 9, wherein the device is a battery cell comprising: the housing; an electrolyte enclosed within the housing and facing the inner surface of the thermoplastic substrate; an anode and a cathode each in contact with the electrolyte; a separator separating the anode from the cathode; and A first terminal and a second terminal are electrically coupled to the anode and the cathode, respectively, and extend outwardly from the housing.

11. A battery module comprising a plurality of electrically connected battery cells, wherein at least one of the battery cells is the battery cell of claim 10.

12. The device according to any one of claims 1 to 9, wherein the device is a battery module comprising the housing and a plurality of electrically connected battery cells disposed in the housing and facing an inner surface of the thermoplastic substrate.

13. A battery pack comprising a plurality of battery modules, wherein at least one of the battery modules is the battery module according to claim 12.

14. The device according to any one of claims 1 to 9, wherein the device is a battery pack comprising a plurality of battery modules disposed in the housing and facing an inner surface of the thermoplastic substrate.

15. The device according to any one of claims 1 to 9, wherein the device is a wrapped inverter comprising the housing and an inverter disposed within the housing and facing an inner surface of the thermoplastic substrate.

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