Mixed metal oxidized hydroxide and method for production
Disclosed are mixed metal oxidized hydroxide precursors that can be used for the preparation of lithium mixed metal oxide cathode materials for secondary lithium ion batteries and methods of making such mixed metal precursors. The precursors typically are particles of nickel, cobalt, and manganese mixed metal oxidized hydroxides with varying metal molar ratios prepared in co-precipitation reactions in two sequential reactors.
1. A mixed metal oxidized hydroxide precursor material represented by the chemical formula:
(1− z )(Ni a Co b Mn c (OH) 2(a+b+c) .Co b′ Mn c′ (OOH) b′+c′ .Mn c″ O 2c″ ). z (Ni d Co e Mn f (OH) 2(d+e+f) .Co e′ Mn f′ (OOH) e′+f′ .Mn f″ O 2f″ ), wherein
0<z<0.1;
A=a, B=b+b′, C=c+c′+c″, A+B+C=1 and 0<A<1, 0<B<1, 0<C<1;
D=d, E=e+e′, F=f+f′+f″ D+E+F=1 and 0<D<1, 0<E<1, 0<F<1; and
A<D, B>E, C>F.
the precursor material comprises spherical and non-spherical particles having a surface and an interior, and
the particles have a gradient structure wherein a molar ratio of Ni, in comparison to Co and Mn, is in the majority at the surface, and a composition with a metal molar ratio that varies from the surface towards the interior of the particles, and
the surface of the particles has a Ni:Co:Mn ratio of about 8:1:1.
2. The precursor material of claim 1 , wherein the particles are doped with at least one metal ion selected from the group consisting of Mg, Al, Zr, Ti, Ni, Co, and Mn.
3. The precursor material of claim 1 , wherein the precursor material has an average particle size (D50) in the range from 3-30 microns.
4. The precursor material of claim 3 , wherein the precursor material has an average particle size (D50) in the range from 7-13 microns.
5. The precursor material of claim 1 , wherein the precursor material has a tap density in the range from 0.8-2.8 g/cm 3 .
6. The precursor material of claim 5 , wherein the precursor material has a tap density in the range from 1.8-2.3 g/cm 3 .
7. The precursor material of claim 1 , wherein the precursor material has a surface area in the range from 2-20 m 2 /g.
8. The precursor material of claim 7 , wherein the precursor material has a surface area in the range from 2-8 m 2 /g.
9. The precursor material of claim 1 , wherein a sodium level within the precursor material is less than 500 ppm.
10. The precursor material of claim 9 , wherein a sodium level within the precursor material is less than 300 ppm.
11. A lithiated cathode active material for lithium ion batteries prepared with the precursor material of claim 1 .