Overview of AB3 phase metal hydrides
This chapter provides an overview to AB3 phase metal hydrides that can be used for hydrogen storage.
Most of the AB3 binary compounds are able to store hydrogen. However, reversible capacities are relatively modest for this family, and few applications have been foreseen for this type of materials. More recently, the new chemistry made possible by the insertion of light elements (like Mg or Ti) within the blocks AB2 has lead to new families of pseudobinary or ternary systems. By lowering the molecular weight, this has opened new hopes to design compounds with higher specific capacities though cycle life remains scarce. Finally, other stoichiometries like A2B7 or A5B19 based on the same intergrowth model have shown better properties in terms of capacity and life and are nowadays more promising for practical applications, especially regarding alkaline negative electrodes for Ni-MH batteries.