Thermally-Conductive 700 bar Composite Tank for Hydrogen Storage

A low-cost network of fueling stations is needed to see hydrogen fuel cell vehicles gain meaningful market share. According to the Department of Energy, the pre-cooling equipment accounts for about 15% of the cost of a fueling station. This cost could theoretically be eliminated if pre-cooling was no longer necessary. Currently, Type IV composite overwrap pressure vessels are used to store hydrogen on board the vehicle. Pre-cooling is needed to maintain the polymeric liner of these tanks under 85C as heat generated during the quick fill-up could compromise the structural integrity and impermeability to hydrogen of the liner. As a result, on-board hydrogen tanks of a new type or design are needed to enable the removal of the pre-cooling equipment from fueling stations. The proposer is armed with extensive experience with formulation, engineering and manufacturing of thermally-conductive materials for a variety of applications. In parallel, the proposer has established a strong relationship with a manufacturer of composite pressure vessels for the transportation industry. Combining the expertise of these two small businesses, the proposer will lead the effort to incorporate advanced materials currently available from its portfolio into the design and fabrication of thermally-conductive smart hydrogen tanks and reduce or eliminate the need for hydrogen pre-cooling. In Phase I, the thermally-conductive liner material will be manufactured and tested for strength, thermal conductivity and hydrogen permeability at the coupon level. A thermally-conductive overwrap will also be defined theoretically based on the proposer’s existing carbon fiber-based products. In Phase II, the proposer plans to finalize material development and testing, then build a complete 700 bar tank with its manufacturing partner.