Electrochemical hydrogen storage in Li-doped pentacene.

Porous metal-incorporated nanostructured organic compounds represent an innovative concept in hydrogen storage. This work reports in detail the first practical realization of electrochemical hydrogen storage in such a material, Li-doped pentacene. Although lithium doping is at a very low level the conductivity of pentacene increases considerably after the doping of lithium, which makes ordered layer-stacked Li-doped pentacene very promising as electrode material for electrochemical hydrogen storage. A discharge capacity of ca. 238 mA h g(-1) has been achieved in 6M KOH for the Li-doped pentacene electrode, which is comparable to that obtained from commonly used electrode material, LaNi5 alloy for electrochemical hydrogen storage. Furthermore, a great improvement in the hydrogen storage capacity can be expected from the Li-doped pentacene by simply raising the lithium doping level.