High strength metallurgical graphene for hydrogen storage nanocomposites

• Electrical resistance measurement used to assess hydrogen chemisorption in graphene.
• Reversible hydrogen chemisorption by metallurgical graphene was explained.
• Hydrogenated graphene is not stable when in contact with humid oxygen or humid air.
• Hydrogen can be released from graphene at relatively low temperatures.
• HSMG shows superior mechanical performance under cyclic loading conditions.

This work presents the results of an investigation on the atomic hydrogen chemisorption of metallurgical graphene enhanced by plasma discharge at low pressures in the range of 5–20 Pa. It was experimentally revealed that hydrogenated graphene is not stable when in contact with humid oxygen or humid air. Moreover, thermal desorption experiments showed that hydrogen can be released from hydrogenated graphene at relatively low temperatures. Additionally, a numerical simulations were performed of the pressure changes inside the nanogaps of hydrogen storage nanocomposites under various durations of the desorption cycle. Experimental fatigue resistance tests performed along with simultaneous electrical resistance measurements of the graphene sheets were also conducted. Metallurgical graphene shows tensile fatigue performances that might be sufficient to resist the pressure pulses and strain that arise in the gaps of graphene-based hydrogen storage systems.