S. Komaba et al., Hydrothermal synthesis of hexagonal tungsten trioxide from Li2WO4 solutionand electrochemical lithium intercalation into the oxide, SOL ST ION, 135(1-4), 2000, pp. 193-197
Tungsten trioxides with an open structure were synthesized by a hydrotherma
l reaction at 120-180 degreesC from an aqueous Li2WO4 solution at pH values
from 0.5 to 2.0. The products contained some water molecules and Lithium i
ons, e.g. as x(Li2O) . WO3 . y(H2O) (x = 0.05-0.11, y - 0.6-0.8), and they
formed at pH 0.5-1.0 and 1.5-2.0 with hexagonal and orthorhombic cells, res
pectively. The x value increased with increasing pH of the Li2WO4 solution
and synthesis temperature. Electrochemical lithium intercalation into the t
ungsten trioxides was investigated in a LiClO4-propylene carbonate electrol
yte solution. The x(Li2O) . WO3 . y(H2O) electrode underwent lithium interc
alation up to Li/W = similar to1 on discharge until 1.5 V vs. Li/Li+. (C) 2
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