Synthesis, Structure and Electrochemical Lithium Intercalation Chemistry of Ramsdellite‐Type LiCrTiO 4

LiCrTiO 4 , which crystallizes in the orthorhombic ramsdellite structure, has been obtained by heating spinel LiCrTiO 4 at 1250 °C in air. The refined cell parameters are a = 4.9835(6) Å, b = 9.5095(8) Å and c = 2.9282(2) Å, space group Pbnm , as determined from Rietveld refinement of X‐ray powder diffraction data. The intercalation chemistry of LiCrTiO 4 has been investigated. Lithium can be extracted from LiCrTiO 4 due to oxidation of Cr III at rather high potential 4 V. On the other hand, lithium intercalation proceeds readily at 1.5 V due to the reduction of tetravalent titanium. Regarding practical applications, as an electrode for lithium rechargeable batteries, specific capacities of 100 and 120 mAh·g −1 are developed at 0.1 mA·cm −2 , respectively. These findings point out that the ramsdellite form of LiCrTiO 4 may be an ambivalent electrode, which can be used either as the positive electrode or the negative electrode of a lithium ion rechargeable battery.