  Lithium-ion batteries (LiBs) based on insertion electrodes reach intrinsic
capacity limits. Performance improvements and cost reduction require
alternative reaction mechanisms and novel battery chemistries such as
conversion reactions and sodium-ion batteries (NaBs), respectively. We here
study the formation of Ti1-xVxH2 hydrides (0 < x < 1) and their electrochemical
properties as anodes in LiBs and NaBs half-cells. Hydrides were synthesized by
mechanochemistry of the metal powders under hydrogen atmosphere (PH2~ 8 MPa).
For V contents below 80 at.% (x < 0.8), single-phase pseudobinary dihydride
compounds Ti1-xVxH2 are formed. They crystallize in the fluorite-type structure
and are highly nanostructured (crystallite size < 10 nm). Their lattice
parameter decreases linearly with the V content leading to hydride
destabilization. Electrochemical studies were first carried out in Li-ion half
cells with full conversion between Ti1-xVxH2 hydrides and lithium. The
potential of the conversion reaction can be gradually tuned with the vanadium
content due to its destabilization effect. Furthermore, different paths for the
conversion reaction are observed for Ti-rich (x < 0.25) and V-rich (x > 0.7)
alloys. Na-ion half-cell measurements prove the reactivity between (V,Ti)H2
hydrides and sodium, albeit with significant kinetic limitations
