Vehicle Electrification, Hydrogen Mobility and Demand for Aluminum Surface Treatment — The Role of Anodizing in Lightweighting, Electric Motor and Hydrogen Tank Components
With the spread of electrification and hydrogen vehicles, aluminum use is increasing in battery housings, electric motors and metal components of hydrogen tanks. This article summarizes the insulation, corrosion resistance and wear resistance roles anodizing plays in these components, and what the discussion on easing the EU 2035 regulation means for demand.
Vehicle electrification is driving up aluminum use. According to the Ducker survey released by the Aluminum Association (U.S.) in April 2023, aluminum content in North American light vehicles is expected to reach 550 lb (about 250 kg) per vehicle by 2030, with battery housings, electric motors and drivetrains, and door sills and rockers cited as growth drivers in electric vehicles over 2022–2030. Battery-electric light trucks were expected to average 644 lb in 2030.
Role of Anodizing by Component
| Component | Required function | Contribution of the anodic coating |
|---|---|---|
| Battery housing and tray | Corrosion resistance, electrical insulation, protection of cooling channels | The coating itself is an insulator; sealing improves insulation and corrosion resistance |
| Electric motor housing and cover | Corrosion resistance, heat dissipation, wear resistance at bearing seats | Wear resistance and insulation of hard coatings; higher emissivity |
| Hydrogen tank boss (nozzle) and valve components | Gas tightness, corrosion resistance, prevention of damage during assembly | Corrosion- and wear-resistant coating on boss surfaces such as Al 6061 |
| Electrical and connector brackets | Insulation or grounding | Insulation through coating thickness; grounding areas secured by masking |
Hard anodic coatings are reported to have a dielectric strength of about 400–600 V/mil; their thermal conductivity is tens of times lower than that of aluminum, but emissivity rises to around 0.8 (Semano, AAC). In electric components, these insulation and heat dissipation characteristics and the dimensional change (growth of about 1/2 of the coating thickness) must be considered together at the design stage.
Hydrogen Mobility
According to Hyundai Motor Group, the all-new NEXO released in 2025 increased hydrogen storage capacity from 6.33 kg to 6.69 kg, reduced tank weight by about 3.6 kg through a lightweight design, and offers a driving range of 720 km per refueling (with 18-inch wheels). A Type IV hydrogen tank consists of a polymer liner wrapped with carbon fiber, with metal bosses at both ends. The model studied by Shao et al. (World Electric Vehicle Journal, 2024) uses AL 6061 for the boss, HDPE for the liner and a T800-grade carbon fiber composite for the reinforcement layer, and identifies the boss as the determinant of sealing performance. Because the boss is a precision component in direct contact with the liner and piping, there is demand for surface treatment that provides corrosion resistance and prevents scratching during assembly.
Discussion on Easing the EU 2035 Regulation
On 2025-12-16, the European Commission announced its automotive package and proposed an amendment adjusting the 2035 CO₂ reduction target for cars and vans from 100 % to 90 %. The remaining 10 % would be offset through the use of EU-made low-carbon steel, e-fuels and biofuels, allowing new registrations of vehicles with combustion engines, such as plug-in hybrids and range extenders, after 2035. The proposal requires approval by the European Parliament and the Council. From the surface treatment industry's perspective, the key point is that demand for electrified components, including hybrids, and for lightweight aluminum components will be sustained even if the transition to battery electric vehicles slows.
Preparations Required of Suppliers
- A measurement system capable of including electrical property tests such as insulation resistance and withstand voltage in inspection reports
- Stronger traceability (lot and process records) and foreign matter control for hydrogen and high-pressure components
- Process design capability for materials that are difficult to anodize, such as die-cast housings
EF Technology consults with customers in advance on anodizing specifications for electrification and hydrogen components.
References
- The Aluminum Association (2023-04-10), New Survey of Automakers Confirms Aluminum Use Expected to Grow in New Electric Vehicles
- Hyundai Motor Group, The all-new NEXO hydrogen tank: safety and lightweighting
- Shao et al., Lightweight Type-IV Hydrogen Storage Vessel Boss Based on Optimal Sealing Structure, World Electric Vehicle Journal (2024)
- European Commission, Automotive package (2025-12-16)
- European Commission press release IP/25/3051
- Semano, Hard Anodizing Properties and Performance (insulation and thermal properties)
- AAC Technical Bulletin 2-05