CATHODE ACTIVE MATERIAL AND METHOD FOR MAKING SUCH CATHODE ACTIVE MATERIAL

Abstract

Cathode active material in particulate form with a mean particle diameter in the range from 2 to 16 .Math.m (D50), wherein the cathode active material has the composition Li.sub.1+xTM.sub.1-xO.sub.2 wherein x is in the range of from 0.1 to 0.2 and TM is a combination of elements according to general formula (I), (Ni.sub.aCo.sub.bMn.sub.c).sub.1-d-eM.sup.1.sub.dM.sup.2.sub.e where the variables are each defined as follows: a is in the range from 0.20 to 0.40, b is in the range of from zero to 0.15, c is in the range of from 0.50 to 0.75, d is in the range of from zero to 0.015, and e is in the range of from zero to 0.02, M.sup.1 is selected from Al, Ti, Zr, Mo, W, Fe, Nb, and Mg, M.sup.2 is selected from B and K, with a + b + c = 1.0 wherein said composite oxide has a specific surface (BET) in the range from 0.5 m.sup.2/gto 10 m.sup.2/gand a pressed density of at least 2.9 g/cm.sup.3, and wherein said cathode active material has an average primary particle diameter in the range of from 200 to 3,000 nm.

Claims

1-10. (canceled)

11. A cathode active material in particulate form with a mean particle diameter ranging from 2 .Math.m to 16 .Math.m (D50), wherein the cathode active material has a composition Li.sub.1+xTM.sub.1-xO.sub.2, wherein x ranges from 0.1 to 0.2 and TM is a combination of elements according to general formula (I), ##STR00008## wherein: a ranges from 0.20 to 0.40, b ranges from zero to 0.15, c ranges from 0.50 to 0.75, d ranges from zero to 0.015, and e ranges of from zero to 0.02, M.sup.1 is selected from Al, Ti, Zr, Mo, Fe, Nb, and Mg, M.sup.2 is selected from B and K, with a + b + c = 1.0 wherein the composite oxide has a specific surface (BET) ranging from 0.5 m.sup.2/g to 10 m.sup.2/g and a pressed density of at least 2.9 g/cm.sup.3, and wherein the cathode active material has an average primary particle diameter in the range of from 200 nm to 3,000 nm.

12. The cathode active material according to claim 11, wherein the specific surface ranges from 0.7 m.sup.2/g to 5 m.sup.2/g.

13. The cathode active material according to claim 11, wherein the pressed density ranges from 3 to 3.6 g/cm.sup.3.

14. The cathode active material according to claim 11, wherein the material has a structural strain of 0.6 % or less for the reflection peak between 29.8° to 30.6° of a corresponding X-Ray diffraction pattern using Mo-Kα X-radiation.

15. The cathode active material according to claim 11, wherein the mean particle diameter D50 ranges from 2 .Math.m to 6 .Math.m.

16. A process for making a cathode active material for lithium ion batteries wherein the process comprises: (a1) mixing a manganese composite (oxy)hydroxide whose metal part has a general formula (II a) ##STR00009## with a source of lithium and a flux agent based on M.sup.2, or (a2) mixing a manganese composite (oxy)hydroxide whose metal part has a general formula (II b) ##STR00010## with a source of lithium and at least one compound of M.sup.1 and a flux agent based on M.sup.2, and (b) calcining the mixture at a temperature ranging from 800° C. to 1050° C., wherein a ranges from 0.20 to 0.40, b ranges from zero to 0.15, c ranges from 0.50 to 0.75, d ranges from zero to 0.015, and e ranges from zero to 0.02, wherein M.sup.1 is selected from Al, Ti, Zr, Mo, W, Fe, Nb, and Mg, and M.sup.2 is selected from B, and with a + b + c = 1.0.

17. The process according to claim 16, wherein the process comprises the additional steps of (c) contacting the resultant lithiated oxide with a mineral acid or an aqueous solution of a compound of M.sup.1 or a combination thereof, wherein M.sup.1 is selected from Al, Ti, Zr, Mo, W, Fe, Nb, and Mg, followed by removal of water, and (d) treating the resultant solid residue thermally, or (e) treating the resultant solid residue with boric acid, followed by thermal treatment.

18. The process according to claim 17, wherein the removal of water is performed by a solid-liquid separation step.

19. The process according to claim 16, wherein the flux agent is boric acid.

20. The process according to claim 16, wherein from 0.1% to 2 % by weight of flux agent is added in step (a1) or (a2) and the percentage referring to the manganese composite (oxy)hydroxide.

Description