Positive electrode active material, non-aqueous electrolyte secondary cell and method for preparation thereof
AssigneeSony Corporation
InventorYosuke Hosoya
Life of this patent
Estimating the term…
Abstract
A non-aqueous electrolyte cell having improved cyclic characteristics at elevated temperatures. The non-aqueous electrolyte cell includes a positive electrode, a negative electrode and a non-aqueous electrolyte. The positive electrode contains, as a positive electrode active material, a lithium transition metal composite oxide represented by the general formula LiCoxAyBzO2 where A denotes at least one selected from the group consisting of Al, Cr, V, Mn and Fe, B denotes at least one selected from the group consisting of Mg and Ca and x, y and z are such that 0.9≦x<1, 0.001≦y≦0.05 and 0.001≦z≦0.05.
Claims11
A method for the preparation of a positive electrode active material comprising the steps of:
- (a) mixing a cobalt compound, a lithium compound, a compound of at least one element selected from the group consisting of aluminum, chromium, vanadium, manganese and iron and a compound of at least one element selected from the group consisting of magnesium and calcium, at a pre-set ratio;
- and
- (b) sintering a mixture from the mixing step to produce a compound represented by the general formula LiCoxAyBzO2 where A denotes at least one element selected from the group consisting of Al, Cr, V, Mn and Fe, and B denotes at least one element selected from the group consisting of Mg and Ca, and x, y and z are such that 0.9≦x<1, 0.001≦y≦0.05, and 0.001≦z≦0.05;
- the compound of at least one element selected from the group selected from the group consisting of magnesium and calcium, as used in the mixing step, being magnesium carbonate or calcium carbonate.
A method for the preparation of a non-aqueous electrolyte secondary cell comprising a positive electrode, a negative electrode, and a non-aqueous electrolyte interposed between the positive and negative electrodes, comprising, in producing the positive electrode, the steps of:
- (a) mixing a cobalt compound, a lithium compound, a compound of at least one element selected from the group consisting of aluminum, chromium, vanadium, manganese and iron and a compound of at least one element selected from the group consisting of magnesium and calcium, at a pre-set ratio;
- and
- (b) sintering a mixture from the mixing step to produce a compound represented by the general formula LiCoxAyBzO2 where A denotes at least one element selected from the group consisting of Al, Cr, V, Mn and Fe, and B denotes at least one element selected from the group consisting of Mg and Ca, and x, y and z are such that 0.90≦x<1, and 0.001≦y≦0.05, and 0.001≦z≦0.05;
- and the compound of at least one element selected from the group consisting of magnesium and calcium, as used in the mixing step, being magnesium carbonate or calcium carbonate.
Dependencies are inferred from the claim text.