LOW-VOLTAGE BEHAVIOR OF LITHIUM-METAL DICHALCOGENIDE TOPOCHEMICAL CELLS

The formation of Li2VX2 (X = S, Se) in Li/Li+, propylene carbonate (PC)/LiVX2 cells occurs near 1.0V. The selenide, Li2VSe2, has been previously described. Magnetic susceptibility and x-ray powder diffraction data are presented for Li2VS2. The LiVX2/Li2VX2 couples are reversible and two phase between the limiting compositions. The selenide is reversible over the range VSe2 to Li2VSe2, but the sulfide deteriorates if not confined to the LiVS2/Li2VS2 couple. TiS2 has a similar voltage profile, near 0.5V assigned to the LiTiS2/Li2TiS2 couple, which appears to be reversible, but is accompanied by either side reaction with the electrolyte or slow decomposition of Li2TiS2. © 1979, The Electrochemical Society, Inc. All rights reserved.