Graphene Supports for Metal Hydride and Energy Storage Applications

Abstract

Energy production, distribution, and storage remain paramount to a variety of applications that reflect on our daily lives, from renewable energy systems, to electric vehicles and consumer electronics. Hydrogen is the sole element promising high energy, emission-free, and sustainable energy, and metal hydrides in particular have been investigated as promising materials for this purpose. While offering the highest gravimetric and volumetric hydrogen storage capacity of all known materials, metal hydrides are plagued by some serious deficiencies, such as poor kinetics, high activation energies that lead to high operating temperatures, poor recyclability, and/or stability, while environmental considerations related to the treatment of end-of-life fuel disposal are also of concern. A strategy to overcome these limitations is offered by nanotechnology, namely embedding reactive hydride compounds in nanosized supports such as graphene. Graphene is a 2D carbon material featuring unique mechanical, thermal, and electronic properties, which all recommend its use as the support for metal hydrides. With its high surface area, excellent mechanical strength, and thermal conductivity parameters, graphene can serve as the support for simple and complex hydrides as well as RHC (reactive hydride composites), producing nanocomposites with very attractive hydrogen storage properties.