Production method of lithium-containing composite oxide and lithium-containing composite oxide
There is provided a production method of a lithium-containing composite oxide capable of improving performances of cycle characteristics, rate characteristics, and the like of a lithium ion secondary battery. A production method of a lithium-containing composite oxide is characterized in that when producing a lithium-containing composite oxide by mixing a transition metal hydroxide containing Ni and Mn essentially and a lithium source and heating the mixture, a transition metal hydroxide having a crystallite diameter of the (100) plane being 35 nm or less in a crystal structure model in the space group P-3m1 of an X-ray diffraction pattern is used.
1. A process for producing a lithium-comprising composite oxide, the process comprising:
mixing (i) a lithium source, and (ii) a zirconium compound or a tungsten compound, and (iii) a transition metal hydroxide that comprises Ni and Mn and has a (100) plane crystallite size of 35 nm or less in a crystal structure model in the P-3 ml space group of an X-ray diffraction pattern, to obtain a mixture; and
heating the mixture.
2. The process of claim 1 , wherein the transition metal hydroxide is of Formula 1:
Ni x Mn y Co z Me a ( 1 )
wherein
Me is Mg, Ca, Al, Ti, V, Cr, Nb, Mo, W, and/or Zr,
0.3<x<1,
0<y<0.7,
0≤z0.7,
0≤a≤0.1, and
x+y+z+a=1.
3. The process of claim 1 , wherein the heating is at a temperature in a range of from 850 to 930° C.
4. The process of claim 1 , wherein the transition metal hydroxide is obtained by continuously adding transition metal compound solution comprising Ni and Mn essentially and alkali to an aqueous medium containing seed crystals and growing the seed crystals by coprecipitation.
5. The process of claim 4 , wherein the seed crystals are obtained by continuously adding alkali to an aqueous transition metal solution comprising Ni and Mn by coprecipitation method.
6. The process of claim 1 , wherein a quantitative ratio of a total molar quantity, M T , of metal elements comprised in the transition metal hydroxide and a molar quantity, M L , of Li comprised in the lithium source follows Equation 2:
M L /M T >1.02 ( 2 ).
7. The process of claim 6 , wherein a quantitative ratio of the sum molar quantity, M T +Mz, of the M T and a molar quantity, M z , of Zr contained in the zirconium compound or a molar quantity, M z , of W contained in the tungsten compound and the M L of Li follows Equation 3:
M L /(M T +M z )>1.02 ( 3 ).
8. The process of claim 1 , wherein a composition of the lithium comprising composite oxide has Formula 5-A:
Li α ,Ni x Mn y Co z Me a1 O b (5-A),
wherein
Me is W or Zr and optionally further Mg, Ca, Al, Ti, V, Cr, Nb, and/or Mo,
1.02<α<1.2,
0.3<x<1,
0<y<0.7,
0<z<0.7,
0<a1≤0.1,
x+y+z+a1=1, and
1.9≤b≤2.1.
9. The process of claim 2 , wherein Me is Mg.
10. The process of claim 2 , wherein Me is Ca.
11. The process of claim 2 , wherein Me is Al.
12. The process of claim 2 , wherein Me is Ti.
13. The process of claim 2 , wherein Me is V.
14. The process of claim 2 , wherein Me is Cr.
15. The process of claim 2 , wherein Me is Nb.
16. The process of claim 2 , wherein Me is Mo.
17. The process of claim 2 , wherein Me is W.
18. The process of claim 2 , wherein Me is Zr.
19. The process of claim 2 , wherein 0.33<x<0.8.
20. The process of claim 2 , wherein 0.1<z<0.6.