14c Multiscale Bioinspired Enhancement Of Natural-Fiber Composites For Green Vehicles

The global number of passenger vehicles is forecasted to rise from 1,102 million in 2017 to 1,980 million by 2040. Reducing greenhouse gas emissions and dependence on petroleum-based solutions has been the focus of the United States Department of Energy’s Vehicle Technology Office. The use of lightweight fiber-reinforced composite materials is key to enable lower emission vehicles and promote the widespread adoption of long-range electric vehicles, offering a significant opportunity to achieve the decarbonization of transportation in America. However, conventional composites used in automotive, such as carbon fiber and glass fiber use petroleum-based, high embodied energy constituents which are difficult to recycle and dispose. Green composites making use of natural fibers and/or biopolymers have a low carbon footprint and outstanding end-of-life properties. However, green composites do not perform as well as their petroleum-based counterparts, hindering their wider adoption in high-volume automotive structural components. Based on the needs for disruptive green composites with high mechanical performance, impact resistance, durability, and multifunctional features, in this Phase I project, an innovative multiscale material design framework is proposed. The framework will lead to a cost effective and scalable green composite that can be used in structural automotive components, replacing petroleum-based composites, with no compromise in terms of safety and strength. Additionally, the proposed approach will deliver non-structural functionalities, such as improved thermal management, self-healing and electrical conductivity. Such multifunctionalities become increasingly important to deliver “smart” vehicles characterized by high system integration and lower manufacturing carbon footprint. The Phase I goal is to develop and demonstrate a new high-performance green composite material with similar specific stiffness and strength to petroleum-based composites, but being more recyclable, having a lower carbon footprint and with significantly reduced total manufacturing energy. Natural fibers including flax and kenaf will be blended with different polymers characterized by different levels of sustainability and performance. Experimental and numerical activities will be performed to optimize the green composite performance at different length scales. The resulting optimized structure will be rated with a rigorous decision matrix and compared against petroleum-based counterparts based on the level of recyclability, production cost, multifunctionality, specific mechanical performance and carbon footprint. Following this Phase I project, the innovative high-performance green composite will be scaled up throughout Phase II and III, leveraging partnerships with key automotive and raw material suppliers. A pilot application such as an electric-vehicle battery enclosure will be targeted to deliver to market more than 10,000 tons of the newly developed low carbon footprint green material by 2029. The innovation will have a wider impact to extensively enable the use of green composites in other high-performance applications in automotive as well as wind rotor blades and hydrogen pressure vessels.