Reversible Delithiation of Disordered Rock Salt LiVO 2

A rigid crystal lattice, in which cations occupy specific positions, is generally regarded as a critical requirement to enable Li + diffusion in the bulk of conventional cathode materials, whereas disorder is generally considered as detrimental. Herein, we demonstrate that facile and reversible insertion and extraction of Li + is possible with LiVO 2 , a new cation‐disordered rock salt compound (space group: Fm 3 ‾ m ), which is, to the best of our knowledge, described for the first time. This new polymorph of LiVO 2 is synthesized by mechanical alloying. Rietveld refinements of the X‐ray diffractions patterns and SAED (selected‐area electron diffraction) patterns attested the formation of the disordered LiVO 2 rock salt phase. Galvanostatic cycling experiments were employed to characterize the electrochemical performance of the material, demonstrating that reversible cycling over 100 cycles with a discharge capacity around 100 mAh g −1 is possible.