Fuel Cell Electric Vehicles (FCEV) are one of the key technologies for a new sustainable, cleaner and more silent mobility. In FCEV, Hydrogen is stored in a high-pressure tank and is transferred to the fuel cell by tubes and lines where it is converted into electricity. There are several components that make up the hydrogen management system: the hydrogen tank itself, the tank liner, the hydrogen fuel lines and the connectors. The most important aspect of hydrogen management is safety and the materials used to create this system must meet the challenge. Arkema’s advanced materials have a long, proven legacy in some of the world’s most demanding applications. Arkema is able to offer solutions for each component.
High-Performance Polyamide Solutions
Storing sufficient quantities of hydrogen in the vehicle as well as providing efficient consumption of fuel are key challenges for fuel cell electric vehicles. More specifically, a high-pressure tank Type 4 has to withstand an internal pressure of 700 bars, as well as very large range of temperatures from -40C to 85C (cf. standard EC79). It is extremely vital that the tank liner and fuel lines that transfer the hydrogen to the fuel cell act as barriers to avoid any hydrogen leaks.
Hydrogen fuel lines
The challenging requirements needed to produce hydrogen fuel lines and connectors are very similar to those of traditional fuel lines in thermal vehicles. As plastic parts are mainly under-chassis, they are exposed to harsh external environments such as road salts and rocks. Rilsan® PA11 has a solid track record for fuel line applications due to its excellent chemical resistance and mechanical properties such as resistance to impact, temperature, and pressure. In addition to this, it has excellent barrier properties compared to other thermoplastics which is key to avoid hydrogen loss. Associated with other materials in multi-layer structures, Arkema offers a full range of grades based on Rilsan® Polyamide 11 that can be easily processed.
Hydorgen tank liner
The tank liner is the key component in ensuring the safety of hydrogen storage in FCEV vehicles. The excellent intrinsic resistance of Rilsan® PA11 to low temperatures explains its efficiency as a protection barrier. Hydrogen tanks experience huge internal pressure variations, Rilsan® PA11 is proven to resist crack generation and blistering in case of compression and decompression. In addition, Rilsan® PA11 is extremely lightweight which is perfect for electrical vehicle manufacturers that are always looking to reduce weight. Another key advantage of Rilsan® PA11 is its ease of processing. Whether it be rotomoulding, extrusion blow molding, injection molding and welding or extrusion, there is a Rilsan® grade that fits the bill. This high-performance polyamide is not only useful for onboard fuel tanks but can also be used in hydrogen supply Infrastructures such as filling stations.
Thermoplastic resins composite solutions
Hydrogen fuel tanks require two properties to secure the safety and durability: strength and stiffness. Mechanical strength is a key property to resist the impact or force, while stiffness is required for durability to keep the properties to resist deformation. These high performance requirements are required to be able to maintain a pressure of 700 bar. Arkema R&D has developed high performance thermoplastic resins for reinforced composites perfectly suited for hydrogen fuel tank outer surface application. Elium® is the first liquid thermoplastic resins designed for manufacturing composite parts with highly performing mechanical properties. Elium® is a game changing resin that helps to solve the challenges that automotive industry faces:
- Lightweight: 30% to 50% lighter that identical parts made out of steel
- Mechanical properties: while being lighter than metal provides the same level of resistance
- Recyclability: possibility to recycle via de-polymerization
Thinking ahead: Piezoelectric copolymers for pressure tank health monitoring
Safety of hydrogen fuel tank is a high priority for automotive manufacturer and securing the tank system with safety measures to detect leakages and excessive temperatures. We developed revolutionary piezoelectric polymer for efficient fuel tank health monitoring through non-invasive acoustic and ultrasound measurement. P(VDF-TrFE) piezoelectric copolymers, Piezotech® FC, are very sensible to acoustic waves and ultrasounds. Data collected thanks to their sensibility and their integration into a battery will help to improve hydrogen fuel tank lifetime and safety management.