Study of Matter at Extreme Conditions
Hydrogen Storage Production and Fuel Cell Symposium
Miami – Western Caribbean March 8 – 15, 2015
HIGH PRESSURE REACTIVE HYDRIDE COMPOSITE SYSTEMS
Anna-Lisa Chaudhary,1 Nils Bergemann,1 Guanqiao Li,2 Motoaki Matsuo,2 Chiara Milanese,3
Shin-ichi Orimo,2 Claudio Pistidda,1 Thomas Klassen1 and Martin Dornheim1
1
Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Geesthacht , Germany
2
WPI-Advanced Institute for Materials Research, Tohoku University, Sendai, Japan
3
Pavia H2 Lab, Department of Chemistry, Physical Chemistry Division, University of Pavia, Pavia, Italy
Abstract
Hydrogen as an energy carrier can be used in combination with intermittent renewable sources in a complete
clean, green energy production and storage cycle. An effective hydrogen system requires suitable hydrogen
storage materials to enable the storage of excess energy produced by renewable energy to be used at times
when direct production from renewables is not possible. High pressure tanks up to 700 bar are becoming more
cost effective thus increasing the potential for high pressure hydrogen storage materials. Complex hydrides are
very promising hydrogen-storage materials, due to their high gravimetric and volumetric capacities. New
combinations of complex metal borohydrides with the transition metal complex hydrides, ScH2 or Mg2FeH6 have
been studied under high pressure hydrogen conditions. The absorption and desorption properties of the
Reactive Hydride Composite (RHC) systems of Li, Mg and Ca borohydrides with ScH2 were characterised
under hydrogen pressures ranging from atmospheric conditions to a several hundred bar. The effect of high
pressure on those systems significantly affected their hydrogen sorption properties. Another RHC system
containing light metal borohydrides MBH4 (where M = Li, Na, Mg, K or Ca) was milled with Mg2FeH6 and again
the absorption and desorption properties characterised. It was found that these light metal borohydrides
combined with Mg2FeH6, at a specific anionic ratio, underwent simultaneous desorption of the two hydrides,
which resulted in a single event of hydrogen release. Effects of high pressure absorption on these borohydridesMg2FeH6 systems also showed different behaviour to atmospheric conditions.