The U.S. Department of Energy Office of Energy Efficiency and Renewable Energy's Fuel Cell Technologies Office and Pacific Northwest National Laboratory hosted the "Advanced Composite Materials for Cold and Cryogenic Hydrogen Storage Applications in Fuel Cell Electric Vehicles" workshop in Dallas, Texas, on October 29, 2015. This workshop was co-located with the Composites and Advanced Materials Expo (CAMX). The objectives of this workshop were to (1) gather input and discuss the state of knowledge on composite materials and processing for use at sub-ambient temperatures and (2) identify research needs and recommended development pathways for use of composite materials at sub-ambient temperature high-pressure applications. This input will be used to help guide future activities for the DOE hydrogen storage program.
Compact, reliable, safe, and cost-effective storage of hydrogen is a key technology requirement for the widespread commercialization of fuel cell electric vehicles (FCEVs) and other hydrogen fuel cell applications. While some light-duty FCEVs with a driving range of about 300 miles are emerging in limited markets, affordable onboard storage still remains a roadblock to commercialization beyond limited vehicle platforms and niche markets. A key challenge is how to store sufficient quantities of hydrogen onboard without sacrificing passenger and cargo space. While the energy per mass of hydrogen is substantially greater than that of most other fuels, its energy by volume is much less than that of liquid fuels such as gasoline. The current state of the art is to store hydrogen in composite overwrapped pressure vessels (COPVs) with polymer liners at 700 bar pressure. To make the systems more compact, longer-term research focuses on developing advanced hydrogen storage technologies that can provide greater energy density than 700 bar compressed hydrogen, at a competitive cost. Research is now being performed for high-pressure hydrogen storage at cold (e.g., ~200 K) and cryogenic (e.g., <<200 K) temperatures. Cold and cryogenic-compressed hydrogen storage systems allow designers to store the same quantity of hydrogen—either in smaller volumes at similar pressures or in similar volumes at lower pressures—thus providing higher hydrogen densities for the widespread commercialization of FCEVs. The intent of this workshop was to help identify the implications of using composite materials in these low-temperature, high-pressure, long-cycle-life applications and knowledge gaps that need to be addressed.