| abstract |
There are disclosed spinel-type lithium cobalt manganese-containing complex oxides having a crystal structure classified as a space group Fd-3m wherein the oxides have a crystallite size measured by a Rietveld method using the fundamental method of 100 nm to 200 nm, an interatomic distance of Li-0 of 1.80 Å to 2.00 Å. and a strain of 0.20 to 0,50. The oxides are represented by the general formulae Lix(CoyMn3-x-y)O4-δ (wherein 0.90 ≤ x ≤1.15 and 0.75 ≤ y ≤1.25) or Lix(CoyMzMn3-x-y-z)O4-δ (wherein 0.90 ≤ x ≤1.15 and 0.90 ≤ y ≤1.25 and 0 < z ≤ 0.3) and M is Ni or a combination of Ni with one or more of Mg, Ti, Al, Ba, Cr, Fe, Mo, W, Zr, Y and Nb. The use of δ symbolises the general oxygen deficiency of spinel oxide structures. The materials may be used as a positive electrode active substance in a lithium secondary cell. |