Electrical Manufacturing Coatings in The Automotive Industry

There is growing interest in the world of electric vehicles (EV). Governments are mandating the reduction of fossil fuel usage, and some drivers are looking at EVs as a way to reduce fuel costs. With an eye on this growing market, virtually every automotive manufacturer is looking to launch new electric vehicles.

The growth of this market segment has caught the attention of coatings manufacturers. The global EV powder coating market which was USD 571.6 million in 2023, is expected to reach USD 1,089.75 million by 2031, and is expected to undergo a CAGR of 8.4% during the forecast period of 2024 to 2031, according to Data Bridge Market Research.

PPG exhibited at the Battery Show North America, showcasing its portfolio of functional coatings, adhesives and sealants designed to address the challenges within the EV market.  AkzoNobel added new powder coatings technology for EV batteries this year.

There is a tremendous amount of technology involved in electric vehicles, beginning with the batteries that power the vehicles. The ability to drive longer distances is a factor, as is the ability to recharge the battery as quickly as possible.

One of the lesser-known technological aspects of EV batteries is the coatings that these batteries use. These coatings help physically protect the battery as well as managing the temperature of the battery. For the most part, powder coatings are the coatings of choice.

What are Electrical Manufacturing Coatings?

So, what types of coatings are used for EV batteries? Tomasz Kluczewski, commercial director North Europe and commercial global EV coordinator of AkzoNobel’s Powder Coatings business, observed that powder coatings are the ultimate solution for EVs, offering comprehensive protection and sustainability.

•  Corrosion-resistant coatings protect metals from rust and degradation.
•  Thermal interface materials manage heat transfer between components.
•  Intumescent coatings enhance safety during thermal runaway events.
•  Electrocoats provide uniform coverage and improved adhesion.
•  Adhesives securely bond components while offering insulation.

He added that these coatings, especially powder coatings, are becoming crucial in protecting EV batteries and their components.

“They ensure optimal battery performance and longevity by providing even, effective insulation against electricity and heat, while also being an eco-friendly option with no VOCs, minimal waste and superior durability,” Kluczewski noted. “These coatings help safeguard battery housings, side plates and modules near cooling systems from overheating, as well as other risks that could compromise performance and safety.”

Kluczewski observed that temperature control is vital for battery performance.

“If a battery gets too cold, its power output drops, reducing the vehicle’s range,” Kluczewski said. “Conversely, excessive heat accelerates battery degradation. Powder coatings help manage these extremes by insulating and protecting components, ensuring the battery remains within its optimal temperature range.

“Moreover, powder coatings enhance the long-term durability of EV batteries by providing corrosion resistance and shielding against other potential threats,” Kluczewski added. “Beyond the battery itself, these coatings protect the broader electrical systems within the vehicle, such as hairpin stators, busbars and other components that must endure high temperatures. This protection is especially important with fast chargers, which can generate significant heat in just a few minutes. By mitigating these heat extremes, powder coatings contribute to the vehicle’s longevity and operational safety.”

David Fetterman, global automotive coatings market director for Adhesives & Sealants and Electrification, PPG, observed that coating systems help to mitigate many challenges of a quickly scaling industry by broadening the engineering design space in electric vehicle batteries.

“Coatings provide the required functionality or multifunctionality for a given environment, while relying on application methodologies and chemistries that are known to the automotive industry,” Fetterman pointed out. “PPG’s contributions to EV development include advanced battery fire protection, thermal management, dielectric isolation, and shielding coating solutions.

“PPG also offers a comprehensive mix of market proven solutions for vehicle corrosion and impact protection,” Fetterman added. “Electrocoat, powder coatings, and polyurea can be used based on the specific performance requirements, and all will support high volume automated application.”

Fetterman noted that lithium-ion battery cells and packs are also enabled by functional coatings.

“Inside the cells, the electrodes use specialized functional coatings ‘pigmented’ with battery active materials and applied in a coating process to aluminum and copper foils,” Fetterman said. “Dielectric coatings help ensure that high voltage packs operate safely without short circuits, while thermal coatings help ensure that the cells stay within the optimal and safe operating temperature range.

“In case of a thermal runaway event, fire protection coatings minimize and contain the fire to allow occupants of the vehicle time to escape safely,” added Fetterman. “Increasingly, multifunctional coatings that provide combinations of corrosion protection, adhesion, dielectric isolation, thermal management, flame resistance and fire protection are being specified.” 

The History of EV Coatings

Coatings manufacturers have only been working on electrical manufacturing coatings since the technology was introduced, but the basics of the technology go back a lot longer, such as intumescent coatings to protect against fire.

Kluczewski noted that AkzoNobel’s journey in coatings for EV batteries builds on more than 60 years of expertise in electrical insulation with its Resicoat powder coatings.

“This extensive background in trusted, tested electrical insulation provided a solid foundation for developing world class EV products,” added Kluczewski. “We didn’t start from scratch; we applied decades of knowledge to this evolving field.

“Leveraging our past experience, UL-approved standards and current technical expertise, we’ve significantly expanded the applications of our coatings,” he continued. “Today, our products not only protect the vehicle’s exterior, but also its internal components. We offer solutions designed to safeguard and enhance every part of an EV, from battery housings and side plates to cooling systems, delivering exceptional thermal shock resistance, strong adhesion and high dielectric strength.”

Kluczewski pointed out that AkzoNobel’s range includes specialized coatings for cooling tubes and plates, which enhance both vehicle safety and battery performance.

“We also provide busbar coatings with improved heat dissipation and extended lifespan under thermal impact, as well as powders specifically designed for the electrical insulation of welded hairpin stators,” added Kluczewski. “These products ensure consistent electrical insulation throughout the life of key components, supporting optimal performance for both EVs and hybrids, and delivering superior thermal conductivity, edge coverage and continuous, void-free film coverage.”

“Over the last decade, PPG has been enhancing our technologies and solutions for battery applications. Within that timeline we have expanded beyond our legacy solutions, such as electrocoat, to developing thermal interface materials, fire protection, and dielectric isolating solutions,” Fetterman said.

“Today, PPG is a full system supplier for battery systems,” he added. “Currently, OEMs have to work through multiple coating suppliers and validate combinations together, while PPG offers the entire platform. For example, we layer our solutions, such as powder and electrocoat, to provide additional customer benefits. Layering can meet many component, design and supply specific needs, including dynamic dielectric isolation specifications; thickness constraints; thermal impedance requirements; and OEM and tier supplier automated mass production capabilities and capital assets.”

Key Characteristics of EV Battery Coatings

There are important chraacteristics for coatings for EV batteries. Fetterman noted that controlling throughput and voltage is one example; protecting against fire is another. He observed that applying coatings to battery components has commercially solved industry challenges by inherently being conformal, automated and sustainable.

High Throughput, Voltage Isolation, and Thermal Management

“Our dielectrically isolating powder coating solutions, for example, have high throughput and voltage isolation while being produced with recycled content,” Fetterman said. “Coatings also play a critical role to enable consumer requirements such as fast charging.

“Thermal interface materials assist in the transfer of heat and work to ensure the batteries remain operating in their preferred temperature window,” Fetterman added. “If the battery pack has the appropriate dielectric isolation and adequate thermal management, the risk of fire or thermal runaway is greatly reduced. As a last line of defense, fire protection coatings can play an essential role for safety of vehicle occupants and first responders in the event of a vehicle collision or unforeseen event.”

Electrical Insulation and Thermal Resistance

Kluczewski observed that these coatings are engineered to deliver crucial performance attributes for electric vehicles.

“They offer excellent electrical insulation, high dielectric strength and robust resistance to corrosion and chemicals,” said Kluczewski. “Additionally, they provide outstanding adhesion, exceptional resistance to thermal shock and superior thermal conductivity. Their consistent film build and edge coverage further enhance their protective qualities.

Resicoat EV Range Standards for Safety

“For example, key products in our Resicoat EV range – specifically designed for the electric vehicle market – meet rigorous industry standards,” Kluczewski reported. “They are UL94 V-0 certified, meaning they can withstand a certain level of flame exposure without igniting. They’re also UL746B and UL1446 approved, ensuring they can resist thermal degradation and damage at elevated temperatures, making them reliable for the demanding conditions within EV systems.”