Hydrogen storage: the remaining scientific and technological challenges

To ensure future worldwide mobility, hydrogen storage in combination with fuel cells for onboard automotive applications is one of the most challenging issues. Potential solid-state solutions have to fulfil operating requirements defined by the fuel cell propulsion system. Important requirements are also defined by customer demands such as cost, overall fuel capacity, refuelling time and efficiency. It seems that currently none of the different storage solid state materials can reach the required storage densities for a hydrogen-powered vehicle. New strategies for storage systems are necessary to fulfil the requirements for a broad introduction of automotive fuel cell powertrains to the market. The combination of different storage systems may provide a possible solution to store sufficiently high amounts of hydrogen.