Morphology effects in MgH2 anode for lithium ion batteries

•Reproducible MgH2 anodes (26 μm thick) optimized and electrochemically tested.•Morphology-cycling relationship demonstrated for MgH2 electrodes upon milling time.•Mg/LiH byproducts become inactive and dependent on cycling rate and particle size.•Failure mechanism may be associated to solid-liquid interface degradation aspects.

In order to acquire reproducible electrodes relevant for Li ion batteries new MgH2 electrodes are successfully obtained from homogenous slurries in N-Methyl-2-Pyrrolidone “NMP” solvent. The electrodes are aimed to elucidate the contribution of the cell components to the electrochemical cycling, in terms of morphology and composition. Various electrode preparations were tested and compared regarding their interaction with Li in a half-cell. The obtained electrochemical cycling curves are discussed according to the ball-milling-induced structural morphology changes and presence of carbon additives, along with the effect of the kinetic rate on the conversion reaction mechanism.