Dielectric coating on inner surface of battery enclosure

Abstract

A battery module 100 for electric vehicles is disclosed, comprising one or more battery cells configured to store and supply electrical energy. The battery module includes a battery enclosure 102 fabricated from Magnesium or Magnesium alloys, such as AZ91D. A dielectric coating 104, is uniformly applied to the inner surface of the battery enclosure 102, composed of insulating materials including ceramic-based coatings, fluoropolymer coatings, epoxy-based resins, high-density coatings, and hybrid polymer-ceramic coatings. The dielectric coating 104 is applied using a spray deposition process to ensure uniform coverage and adhesion. The battery module 100 provides enhanced electrical insulation, thermal management, and environmental protection, making it suitable for high-performance electric vehicles.

Description

DIELECTRIC COATING ON INNER SURFACE OF BATTERY ENCLOSUREFIELD OF INVENTION

[0001] The present invention generally relates to battery modules for electric vehicles. More specifically, the present invention is related to a battery module with dielectric coating.BACKGROUND OF THE INVENTION

[0002] The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also correspond to implementations of the claimed technology.

[0003] Battery enclosures play a crucial role in the safety, efficiency, and longevity of battery cells used in electric vehicles (EVs). The battery enclosures provide mechanical protection, electrical insulation, thermal management, and environmental resistance while ensuring the reliability of the battery cells. Magnesium and Magnesium alloys are increasingly preferred for battery enclosures due to their lightweight nature, high strength-to-weight ratio, and excellent thermal conductivity. However, the use of Magnesium battery enclosures introduces several challenges, particularly in terms of electrical insulation, corrosion resistance, and thermal performance.

[0004] One primary challenge is the risk of electrical short circuits within the battery module. Magnesium is a conductive material, and without proper insulation, direct contact between battery cells and the enclosure can lead to short circuits, posing safety hazards such as overheating, fire, and battery failure. Conventional insulation techniques, such as the use of Mica sheets, powder coatings, or galvanization, have limitations in achieving uniform and reliable insulation. These methods often introduce unnecessary weight, increase manufacturing complexity, and lack the required dielectric strength for long-term performance.

[0005] Another major issue is corrosion and electrolyte leakage. Magnesium alloys, despite their advantages, are prone to oxidation and corrosion when exposed to battery electrolytes, moisture, or extreme environmental conditions. Existing coatings, such asanodization and conventional polymer coatings, may degrade over time due to chemical exposure, mechanical stress, and thermal cycling, reducing the structural integrity of the battery enclosure.

[0006] Electromagnetic Interference (EMI) and Electromagnetic Compatibility (EMC) also present significant challenges in battery enclosures. EMI can originate from the battery cells, power electronics, and external sources such as radio signals or electric motor controllers. Poor EMI shielding can result in signal distortion, data loss, and malfunctioning of vehicle control systems, including the Battery Management System (BMS). Traditional insulation solutions, such as laminated films or external shielding materials, fail to effectively balance EMI reduction with other essential performance factors such as thermal conductivity and mechanical stability.

[0007] Thermal management is another critical aspect of battery enclosures. Efficient heat dissipation is necessary to maintain optimal battery performance and prevent thermal runaway, a dangerous phenomenon in which excessive heat leads to uncontrollable temperature escalation, potentially causing fire or explosion. Conventional insulating materials, including Mica sheets and thick polymer coatings, often exhibit poor thermal conductivity, leading to heat accumulation within the battery module and reducing battery efficiency.

[0008] Additionally, manufacturing and process efficiency is a key concern. Traditional coating methods, such as powder coating and galvanization, involve multiple processing steps that increase production time and cost. Many existing insulation coatings also suffer from weak adhesion to Magnesium surfaces, leading to delamination, cracking, and reduced reliability over extended operational periods. Moreover, the weight added by conventional coatings counteracts the lightweight advantage of Magnesium enclosures, making them less suitable for high-performance EV applications. Therefore, in light of the above-mentioned challenges, there is a long felt need for an improved battery module for electric vehicles.SUMMARY OF THE INVENTION

[0009] This summary is provided to introduce aspects related to a battery module for electric vehicles and the aspects are further described below in the detailed description. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the claimed subject matter.

[0010] In an embodiment of the present disclosure, a battery module for electric vehicles is disclosed. The battery module comprises a battery enclosure to house one or more battery cells. The battery cells are configured to store and supply electrical energy for vehicle operation. Further, the battery enclosure is fabricated using at least one of Magnesium and one or more Magnesium alloys. Further, the battery module comprises a dielectric coating applied uniformly on an inner surface of the battery enclosure. The dielectric coating is composed of insulating materials, including at least one of ceramic-based coating, fluoropolymer coating, epoxy-based resins, high-density coatings and hybrid polymer-ceramic coatings.

[0011] In an aspect of the present disclosure, the dielectric coating has a thickness ranging from 20 to 100 microns.

[0012] In an aspect of the present disclosure, the dielectric coating has a density between 1.07 g / cm3and 2.0 g / cm3.

[0013] In an aspect of the present disclosure, the dielectric coating has a dielectric strength between 5 kV / mm and 40 kV / mm.

[0014] In an aspect of the present disclosure, the dielectric coating has a thermal conductivity between 0.2 W / m-K and 0.63 W / m-K.

[0015] In an aspect of the present disclosure, the dielectric coating has an adhesion strength of at least 5 MPa.

[0016] In an aspect of the present disclosure, the dielectric coating is applied using a spray deposition process.

[0017] In an aspect of the present disclosure, the one or more Magnesium alloys include at least one of, AZ31 (Magnesium- Aluminum-Zinc alloy), AZ91 (Magnesium- Aluminum-Zinc alloy), AZ91D, AM50 (Magnesium- Aluminum-Manganese alloy), and AM60 (Magnesium- Aluminum-Manganese alloy).

[0018] In an aspect of the present disclosure, the battery module further comprises a battery management system electrically connected to the one or more battery cells, configured to monitor voltage, current, temperature, and state of charge of the one or more battery cells.

[0019] Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings constitute a part of the description and are used to provide a further understanding of the present disclosure. In the drawings:

[0021] Figure 1 illustrates a perspective view of a battery module for electric vehicles, in accordance with an embodiment of the present disclosure;

[0022] Figure 2 illustrates a battery enclosure with a dielectric coating, in accordance with an embodiment of the present disclosure;

[0023] Figure 3 illustrates thickness of the dielectric coating on the battery enclosure, in accordance with an embodiment of the present disclosure;

[0024] Figure 4 illustrates application of the dielectric coating on a battery enclosure using a spray deposition equipment, in accordance with an embodiment of the present disclosure; and

[0025] Figure 5 illustrates a flowchart of a method of applying a dielectric coating on a battery enclosure of a battery module, in accordance with an embodiment of the present disclosure.

[0026] A more complete understanding of the present invention and its embodiments thereof may be acquired by referring to the following description and the accompanying drawings.DETAILED DESCRIPTION OF THE INVENTION

[0027] Exemplary embodiments now will be described with reference to the accompanying drawings. The disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey its scope to those skilled in the art. The terminology used in the detailed description ofthe particular exemplary embodiments illustrated in the accompanying drawings is not intended to be limiting. In the drawings, like numbers refer to like elements.

[0028] It is to be noted, however, that the reference numerals used herein illustrate only typical embodiments of the present subject matter, and are therefore, not to be considered for limiting its scope, for the subject matter may admit to other equally effective embodiments.

[0029] The detailed description includes specific details for the purpose of providing a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details.

[0030] The present invention aims to address the above-mentioned challenges by providing a battery module for electric vehicles (EVs) that enhances performance, safety, and durability. The battery module features a battery enclosure designed to house and protect multiple battery cells while ensuring efficient thermal management and electrical insulation. The battery enclosure is fabricated using Magnesium and Magnesium alloys, offering a lightweight yet strong structure that contributes to overall vehicle efficiency. Additionally, to prevent electrical short circuits, corrosion, and thermal instability, a dielectric coating is uniformly applied to the inner surface of the battery enclosure, providing essential insulation and chemical protection.

[0031] The dielectric coating is composed of high-performance insulating materials, including ceramic -based coatings, fluoropolymer coatings, and epoxy-based resins, ensuring optimal dielectric strength, adhesion, and thermal properties. The coating is applied through a precise spray deposition process, ensuring uniform coverage and long-term reliability.

[0032] Figure 1 illustrates a perspective view of a battery module 100 for electric vehicles, in accordance with an embodiment of the present disclosure. The battery module 100 may be designed to store and supply electrical energy to power various electrical components and drivetrain of an EV. The battery module 100 comprises a battery enclosure 102 to serve as a protective housing for one or more battery cells. The battery cells function as a primary energy storage component, supplying electricity for vehicle propulsion, auxiliary systems, and electronic components. The battery enclosure 102 provides mechanical protection, structural support, and environmental shielding to the one or more battery cells, ensuring durability and safety in real-world operating conditions of the EV.

[0033] The battery enclosure 102 may be fabricated using at least one of Magnesium and one or more Magnesium alloys. Magnesium and the one or more Magnesium alloys are preferred materials for the battery enclosure 102 due to their lightweight properties, high strength-to-weight ratio, and excellent corrosion resistance. The use of Magnesium and the one or more Magnesium alloys significantly reduces overall weight of the battery module 100, thereby enhancing vehicle range and efficiency. Additionally, Magnesium alloys exhibit superior thermal dissipation characteristics, allowing for better heat management within the battery module 100. Proper heat management is crucial for preventing overheating, which could otherwise lead to battery degradation or thermal runaway. The battery enclosure 102 may be designed to be hermetically sealed, preventing the ingress of moisture, dust, and other contaminants, which could compromise battery performance and safety. Furthermore, the battery enclosure 102 may be include structural supports to withstand mechanical shocks, vibrations, and impacts that occur in automotive applications.

[0034] To further enhance safety and operational efficiency, the battery module 100 comprises a dielectric coating 104, which is applied uniformly on inner surface of the battery enclosure 102, as illustrated in Figure 2. The dielectric coating 104 serves multiple functions, including providing electrical insulation, thermal stability, chemical protection, and mechanical durability of the battery module 100. The dielectric coating 104 prevents electrical arcing or short circuits that may occur due to direct contact between the battery cells and the battery enclosure 102. Further, the dielectric coating 104 also functions as a thermal barrier, helping to regulate operating temperature of the battery cells in the battery module 100 and preventing localized heating issues. Furthermore, the dielectric coating 104 provides chemical resistance against electrolyte leakage, protecting the battery enclosure 102 from corrosion and potential material degradation over time.

[0035] The dielectric coating 104 may be composed of one or more insulating materials, including but not limited to ceramic-based coatings, fluoropolymer coatings, epoxy-based resins, high-density coatings, and hybrid polymer-ceramic coatings. The insulating materials may be selected based on their ability to provide long-term durability, resistance to environmental stressors, and compatibility with Magnesium-based battery enclosures. The primary function of the dielectric coating 104 may be to ensure electrical insulation, chemical protection, and thermal management while maintaining the structural integrity of the battery enclosure 102 over extended operational lifetimes.

[0036] Ceramic -based coatings may be employed due to their high dielectric strength, superior thermal stability, and excellent resistance to chemical degradation. The ceramic -based coatings may be composed of materials such as alumina (AI2O3), zirconia (ZrCE), and silicon carbide (SiC), which may exhibit low electrical conductivity and high-temperature resistance. Ceramic -based coatings are suitable for high-power battery applications where heat dissipation and electrical isolation may be critical. Additionally, ceramic coatings may offer high wear resistance, ensuring that the battery enclosure 102 remains protected from mechanical abrasion and electrolyte-induced corrosion.

[0037] Fluoropolymer coatings such as polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), and polyvinylidene fluoride (PVDF) may be used due to their chemical inertness, non-stick properties, and hydrophobic nature. The fluoropolymer coatings may provide exceptional resistance to electrolyte leakage, oxidation, and moisture ingress, ensuring that the battery enclosure 102 remains free from corrosion and electrical failures over time. Furthermore, fluoropolymer coatings may exhibit low surface energy, preventing the adhesion of contaminants and ensuring clean operational conditions within the battery module 100.

[0038] Epoxy-based resins may be applied to form a highly adhesive and impact-resistant dielectric barrier. Epoxy coatings exhibit strong chemical bonds, excellent adhesion to Magnesium substrates, and mechanical toughness, making them ideal for high-vibration environments such as electric vehicles. Additionally, epoxy coatings may be formulated with thermal additives to enhance heat dissipation and maintain optimal battery temperatures during operation.

[0039] Hybrid polymer-ceramic coatings may be incorporated to combine the advantages of polymeric flexibility and ceramic durability. The hybrid polymer-ceramic coatings may offer enhanced mechanical resilience, improved thermal cycling resistance, and optimized electrical insulation properties. Hybrid structure of these coatings may ensure that the dielectric coating 104 remains crack-resistant while effectively withstanding thermal expansion and contraction that may occur during charging and discharging cycles.

[0040] The choice of dielectric coating 104 may depend on various factors, including battery chemistry, operational voltage, temperature ranges, and exposure to environmental conditions. The materials of the dielectric coating 104 may be selected and formulated to ensurethat they maintain their insulating properties over time without degrading, peeling, or delaminating due to chemical exposure, humidity, and temperature fluctuations.

[0041] The dielectric coating 104 may have a thickness ranging from 20 to 100 microns. The thickness range of 20 to 100 microns is carefully chosen to balance insulation efficiency, thermal conductivity, and material usage. A thickness closer to 100 microns is preferred in high-voltage battery modules, where additional insulation is required to prevent electrical breakdown. Further, a thinner thickness of around 20 to 30 microns is used in lightweight battery modules, as illustrated in Figure 3. As in lightweight battery modules, weight reduction is a priority while still maintaining effective insulation. The thickness of the dielectric coating 104 is optimized to ensure that the insulation does not add excessive bulk to the battery module 100 while still offering robust protection.

[0042] The dielectric coating 104 may have a density range between 1.07 g / cm3and 2.0 g / cm3. The density range ensures that the dielectric coating 104 maintains structural stability, preventing cracking, peeling, or degradation under extreme temperature conditions. Higher- density (closer to 2.0 g / cm3) is used in high-performance applications where greater durability and resistance to wear are required. Lower-density (closer to 1.07 g / cm3) is used in lightweight battery modules, where the focus is on reducing overall battery weight without compromising safety or insulation properties.

[0043] Further, the dielectric coating 104 may have a dielectric strength between 5 kV / mm and 40 kV / mm, ensuring effective electrical insulation and protection against high-voltage breakdowns. In high-voltage battery modules, dielectric coating 104 with strengths closer to 40 kV / mm may be preferred to ensure maximum electrical resistance and reliability. Further, in low-voltage battery modules, a dielectric strength closer to 5 kV / mm may be sufficient to prevent electrical failures while maintaining material efficiency.

[0044] Additionally, the thermal conductivity of the dielectric coating 104 may range from 0.2 W / m-K to 0.63 W / m-K, allowing for controlled heat dissipation within the battery module 100. Since battery cells generate heat during operation, the dielectric coating 104 must allow sufficient thermal flow to prevent localized overheating while still providing adequate insulation. In high-performance electric vehicle applications, a higher thermal conductivity coating (closer to 0.63 W / m-K) may be used to improve heat dissipation and temperatureregulation. Further, in standard battery modules, coatings with lower thermal conductivity (around 0.2 W / m-K) are sufficient to maintain stable thermal conditions.

[0045] The adhesion strength of the dielectric coating 104 is at least 5 MPa, ensuring longterm durability and resistance to mechanical stress. The dielectric coating 104 must remain firmly bonded to the inner surface of the battery enclosure 102, even under vibrations, temperature fluctuations, and mechanical shocks that occur in daily vehicle operation. Strong adhesion prevents the dielectric coating 104 from peeling or detaching, which could compromise insulation and lead to potential electrical hazards.

[0046] To ensure uniform application and consistent coating thickness, the dielectric coating 104 is applied using a spray deposition process, as illustrated in Figure 4. The spray deposition process allows for precise control over coating distribution, ensuring that all inner surfaces of the enclosure are evenly covered. The spray deposition process is also highly scalable, making it suitable for mass production in the automotive industry. Additionally, the spray deposition process reduces material waste and ensures that the coating maintains consistent electrical and thermal properties across the entire battery module 100.

[0047] The battery enclosure 102 may be fabricated using at least one of Magnesium and one or more Magnesium alloys, including but not limited to AZ31 (Magnesium- Aluminum- Zinc alloy), AZ91 (Magnesium- Aluminum-Zinc alloy), AZ91D, AM50 (Magnesium- Aluminum-Manganese alloy), and AM60 (Magnesium-Aluminum-Manganese alloy). The Magnesium alloys may be selected due to their lightweight properties, high mechanical strength, corrosion resistance, and thermal efficiency, making them highly suitable for use in battery enclosures for electric vehicles. The use of Magnesium and Magnesium alloys in the battery enclosure 102 may significantly reduce the overall weight of the battery module 100, thereby improving energy efficiency, range, and overall performance of the electric vehicle. Additionally, the structural integrity and impact resistance of the above-mentioned materials may enhance the safety and durability of the battery module under various operational conditions.

[0048] Among the Magnesium alloys considered, AZ91D may be the most preferable material for fabricating the battery enclosure 102 due to superior mechanical and chemical properties of AZ91D. AZ91D is a high-purity Magnesium- Aluminum-Zinc alloy that may exhibit excellent corrosion resistance, particularly when exposed to humid or chemicallyaggressive environments. The corrosion resistance may be attributed to controlled levels of iron, copper, and nickel in AZ91D, which may minimize galvanic corrosion and ensure longterm durability. AZ91D may also possess an outstanding strength-to-weight ratio, which may enhance the structural integrity of the battery enclosure 102 while maintaining a lightweight profile that is crucial for electric vehicle applications.

[0049] Further, AZ91D may offer superior castability, making it highly suitable for complex battery enclosure designs that require precise dimensional accuracy and intricate geometries. Ability of AZ91D to be die-cast with minimal porosity and high surface finish quality may facilitate the manufacturing of battery enclosures with high consistency and reduced machining requirements. Furthermore, AZ91D may exhibit good thermal conductivity, allowing for efficient heat dissipation within the battery module 100. Good thermal conductivity may be particularly advantageous in electric vehicles, where maintaining optimal battery temperature is critical for performance, longevity, and safety. By facilitating rapid heat transfer away from the battery cells, AZ91D may help prevent overheating, thermal runaway, and efficiency losses, ensuring stable operation of the battery module 100 under varying load conditions.

[0050] The selection of AZ91D for the battery enclosure 102 may also be done due to its sustainability and recyclability. Magnesium alloys, including AZ91D, may be fully recyclable, making them an environmentally friendly choice for battery enclosures in electric vehicles. The ability to recover and reuse Magnesium from end-of-life battery modules may contribute to reducing the environmental impact of electric vehicle production and disposal. Furthermore, the lightweight nature of AZ91D may result in reduced energy consumption during vehicle operation, indirectly lowering the overall carbon footprint of electric mobility solutions.

[0051] The combination of lightweight construction, superior mechanical strength, high thermal conductivity, corrosion resistance, EMI shielding, and recyclability may establish AZ91D as the most preferable material for the battery enclosure 102. Its advantageous properties may enable the development of robust, high-performance battery enclosures that enhance the safety, efficiency, and reliability of electric vehicles.

[0052] Furthermore, the battery module 100 may comprise a battery management system (BMS) that may be electrically connected to the battery cells. The BMS may be responsible for monitoring battery parameters, including voltage, current, temperature, and state of charge(SOC). By continuously monitoring the battery parameters, the BMS enhances battery safety and efficiency, preventing conditions such as overcharging, over-discharging, thermal runaway, and cell imbalance. Further, the BMS includes real-time diagnostics and predictive analytics, which allow for early detection of potential battery failures and proactive maintenance alerts. The integration of a BMS with data logging and wireless communication capabilities further enables remote monitoring and optimization of battery performance in electric vehicle applications.

[0053] Figure 5 illustrates a flow chart of a method of applying a dielectric coating on a battery enclosure of a battery module, in accordance with an embodiment of the present invention. It should be noted that in some alternative implementations, the functions noted in the blocks may occur out of the order noted in the drawings. For example, two blocks shown in succession in Figure 5 may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. In addition, the process descriptions or blocks in flow charts should be understood as representing decisions made by a hardware structure such as a state machine.

[0054] The order in which method is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the scope of the subject matter described herein.

[0055] Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof. Furthermore, the above-mentioned methods may be implemented in suitable hardware, computer-readable instructions, or a combination thereof. The steps of such methods may be performed by either a system under the instruction of machine-executable instructions stored on a non-transitory computer-readable medium or by dedicated hardware circuits, microcontrollers, or logic circuits. The method may include the following steps.

[0056] At step 502, an inner surface of a battery enclosure is prepared to enhance adhesion of a dielectric coating. Preparing the inner surface of the battery enclosure includes cleaning, degreasing, and surface roughening. Cleaning is performed to remove dust, oil, grease, and other contaminants that may interfere with adhesion. Cleaning may be carried out using ultrasonic cleaning, solvent-based cleaning, or aqueous-based cleaning. In ultrasonic cleaning,the battery enclosure may be submerged in a cleaning solution, and high-frequency sound waves may create microscopic cavitation bubbles that dislodge contaminants. Solvent-based cleaning may involve the use of alcohols, acetone, or other organic solvents to dissolve and remove impurities, while aqueous-based cleaning may use water-based detergents and surfactants to break down contaminants.

[0057] Degreasing is carried out using solvents or aqueous-based solutions to eliminate residual oils. After degreasing, the enclosure may be thoroughly rinsed with deionized water to prevent residue buildup. Further, surface roughening is achieved through methods such as abrasive blasting, etching, or chemical treatments, depending on the magnesium alloy composition. These processes increase the surface energy of the enclosure, ensuring a strong bond between the coating and the metal surface.

[0058] At step 504, masking may be applied to areas of the battery enclosure that must remain uncoated. Masking may be essential to prevent unintended deposition of the dielectric coating on specific regions, such as electrical contact points, fastener holes, or assembly interfaces. Masking materials may include high-temperature-resistant tapes, removable polymer films, precision stencils, and liquid maskants. High-temperature tapes, such as silicone-based tapes, may be used to cover areas that need to remain coating-free while withstanding the curing temperatures. Polymer films, including PEEK (polyether ether ketone) or PTFE (polytetrafluoroethylene) sheets, may provide a removable protective barrier. Liquid maskants, which may be applied as a viscous coating and later peeled off, may also be used for complex geometries.

[0059] At step 506, the dielectric coating may be applied using spray deposition equipment to ensure uniform coverage and controlled thickness. The coating may be applied using a spray deposition equipment. The spray deposition equipment may include any one of, automated electrostatic spray systems, High-Volume, Low-Pressure (HVLP) spray guns, and plasma spray equipment, depending on material composition of the dielectric coating and properties required from the dielectric coating. Electrostatic spray deposition equipment may use a charged spray mist that is attracted to the oppositely charged metal surface, ensuring even distribution and reducing overspray.

[0060] HVLP spray guns may operate at lower pressure, allowing fine atomization of the dielectric coating and improved control over thickness of the dielectric coating. Plasma sprayequipment may be used for ceramic-based coatings, where the material of the dielectric coating may be heated to a molten state before being deposited onto the battery enclosure. Spray may be applied multiple times to build up the desired coating thickness, typically ranging from 20 to 100 microns.

[0061] At step 508, the dielectric coating undergoes curing and drying. The curing process may depend on the type of dielectric coating and may involve at least one of, thermal curing, UV curing, and chemical curing. Thermal curing may involve placing the coated battery enclosure in a convection oven or infrared heating system, where it may be exposed to controlled temperatures, ranging from 150°C to 300°C, for a specified duration to allow polymerization and cross-linking.

[0062] UV curing may be used for UV-reactive dielectric coatings and may involve exposure to ultraviolet light of specific wavelengths, typically 200-400 nm, to trigger rapid hardening. Chemical curing may involve the use of catalysts, hardeners, and moisture-activated curing agents to facilitate polymerization at room temperature. Proper curing may ensure that the dielectric coating attains optimal mechanical strength, dielectric strength, chemical resistance, and thermal stability. After curing, the battery enclosure may be cooled gradually to minimize thermal stress and prevent coating defects such as cracking or delamination.

[0063] At step 510, quality control inspections may be performed to ensure that the dielectric coating meets industry standards for battery safety, electrical insulation, and environmental protection. The quality control inspections may involve a combination of nondestructive and destructive testing methods to verify the integrity and performance of the dielectric coating. Dielectric strength testing may be conducted by applying a high-voltage electrical field across the coated surface to evaluate its insulation properties, ensuring that it withstands electric stress within the range of 5 kV / mm to 40 kV / mm. Thickness measurement may be performed using techniques such as eddy current testing, micrometer measurements, or laser profilometry to confirm that the coating has been applied uniformly and meets the required thickness specifications.

[0064] Adhesion testing may be carried out using methods including pull-off adhesion tests and cross-hatch tests to assess the ability of the dielectric coating to bond firmly to the battery enclosure without peeling or flaking under mechanical stress. Thermal conductivity measurement may be conducted using laser flash analysis and steady-state heat flow meters todetermine whether the coating effectively dissipates heat, with thermal conductivity values ranging from 0.2 W / m-K to 0.63 W / m-K. Additionally, environmental resistance testing may be performed to evaluate the durability of the dielectric coating under harsh conditions. The environmental resistance testing may include humidity exposure tests, salt spray tests to assess corrosion resistance, and thermal cycling tests to examine the ability of the dielectric coating to withstand temperature fluctuations without degradation.

[0065] If any defects, inconsistencies, or deviations from the required standards are detected during the quality control inspections, corrective measures may be implemented. The battery enclosure may be reprocessed by undergoing surface preparation and re-application of the dielectric coating to ensure compliance with the required performance parameters. The quality control inspections ensure that battery enclosures meeting stringent quality criteria are integrated into the battery module, thereby enhancing the reliability and longevity of the battery module.Technical Advancement and Economic Significance

[0066] The battery module for electric vehicles disclosed in the present invention, may have the following advantages over conventional art:Electrical insulation is effectively ensured by the dielectric coating, preventing electrical short circuits between battery cells and the magnesium enclosure.Corrosion resistance is significantly enhanced as the dielectric coating protects the magnesium enclosure from oxidation, electrolyte leakage, and environmental degradation.Improved thermal management is achieved by utilizing a dielectric coating with optimized thermal conductivity, allowing efficient heat dissipation and preventing thermal runaway.Electromagnetic interference (EMI) is minimized, ensuring better electromagnetic compatibility (EMC) and stable operation of the Battery Management System (BMS) and other electronic components.Manufacturing efficiency is increased by utilizing a spray deposition process, ensuring uniform coating application while reducing production time and complexity.The need for additional insulation materials such as Mica sheets, powder coatings, or galvanization is eliminated, reducing weight, cost, and assembly complexity.Structural integrity and longevity of the battery enclosure are improved as the dielectric coating enhances mechanical durability while maintaining lightweight properties.

[0067] The specification may refer to “an”, “another”, “one” or “some” embodiment s) in several locations.

[0068] This does not necessarily imply that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments.

[0069] The terms “or” and “and / or” as used herein are to be interpreted as inclusive or meaning any one or any combination. Therefore, “A, B or C” or “A, B and / or C” mean “any of the following: A; B; C; A and B; A and C; B and C; A, B and C.” An exception to this definition will occur only when a combination of elements, functions, steps or acts are in some way inherently mutually exclusive.

[0070] As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms “includes”, “comprises”, “including” and / or “comprising” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It will be understood that when an element is referred to as being “connected” or “coupled” to another element, it can be directly connected or coupled to the other element or intervening elements may be present. Furthermore, “connected” or “coupled” as used herein may include operatively connected or coupled. As used herein, the term “and / or” includes any and all combinations and arrangements of one or more of the associated listed items.

[0071] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure pertains. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent withtheir meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0072] Although implementations of a battery module for electric vehicles have been described in language specific to structural features and / or methods, it is to be understood that the appended claims are not necessarily limited to the specific features or methods described.

[0073] The invention has been described above with reference to numerous embodiments and specific examples. Many variations will suggest themselves to those skilled in this art in light of the above-detailed description. All such obvious variations are within the full intended scope of the appended claims.

Claims

We claim:

1. A battery module (100) for electric vehicles, comprises: a battery enclosure (102) to house one or more battery cells, wherein the battery enclosure (102) is fabricated using at least one of Magnesium and one or more Magnesium alloys; and a dielectric coating (104) applied uniformly on an inner surface of the battery enclosure (102), wherein the dielectric coating (104) is composed of insulating materials, including at least one of ceramic -based coatings, fluoropolymer coatings, epoxy-based resins, high-density coatings and hybrid polymer-ceramic coatings.

2. The battery module (100) as claimed in claim 1, wherein the dielectric coating (104) has a thickness ranging from 20 to 100 microns.

3. The battery module (100) as claimed in claim 1, wherein the dielectric coating (104) has a density between 1.07 g / cm3and 2.0 g / cm3.

4. The battery module (100) as claimed in claim 1, wherein the dielectric coating (104) has a dielectric strength between 5 kV / mm and 40 kV / mm.

5. The battery module (100) as claimed in claim 1, wherein the dielectric coating (104) has a thermal conductivity between 0.2 W / m- K and 0.63 W / m- K.

6. The battery module (100) as claimed in claim 1, wherein the dielectric coating (104) has an adhesion strength of at least 5 MPa.

7. The battery module (100) as claimed in claim 1, wherein the dielectric coating (104) is applied using a spray deposition process.

8. The battery module (100) as claimed in claim 1, wherein the one or more Magnesium alloys include at least one of, AZ31 (Magnesium- Aluminum-Zinc alloy), AZ91 (Magnesium- Aluminum-Zinc alloy), AZ91D, AM50 (Magnesium- Aluminum-Manganese alloy), and AM60 (Magnesium- Aluminum-Manganese alloy) .

9. The battery module (100) as claimed in claim 1, further comprises a battery management system electrically connected to the one or more battery cells, configured to monitor voltage, current, temperature, and state of charge of the one or more battery cells.

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