Process for the preparation of crystalline lithium-, vanadium-and phosphate-comprising materials

A process for the preparation of a mixture comprising at least one compound according to general formula (I)

• (I) Lia-bM1bV2-cM2c(PO4)x (I)
• wherein M1, M2, a, b, c and x have the following meanings:
• M1:
• Na, K, Rb and/or Cs,
• M2:
• Ti, Zr, Nb, Cr, Mn, Fe, Co, Ni, Al, Mg and/or Sc,
• a:
• 1.5-4.5,
• b:
• 0-0.6,
• c:
• 0-1.98 and
• x:
• number to equalize the charge of Li and V, and M1 and/or M2, if present, wherein a-b is >0, wherein the compound is in a form consisting essentially of spherical particles or agglomerates having a diameter of from 3 to 200 μm;
• and at least one electrically conducting material;
• wherein the process comprises:
• (A) providing an essentially aqueous mixture comprising at least one lithium-containing compound, at least one vanadium-containing compound in which vanadium has the oxidation state +5 and/or +4, and at least one M1-containing compound, if present, and/or at least one M2-containing compound, if present, and at least one reducing agent which is oxidized to at least one compound comprising at least one phosphorous atom in oxidation state +5,
• (B) drying the mixture provided in (A), in order to obtain a solid compound and
• (C) calcining the solid compound obtained from (B) at a temperature of 300 to 950° C.