PROCESS FOR PRODUCING A SURFACE-MODIFIED PARTICULATE LITHIUM NICKEL METAL OXIDE MATERIAL
A process for producing a surface-modified particulate lithium nickel metal oxide material is provided. The process comprises the addition of a controlled quantity of a coating liquid comprising a metal-containing compound and a lithium-containing compound to nickel metal precursor particles using an incipient wetness process followed by a calcination step.
1 . A process for producing a surface-modified particulate lithium nickel metal oxide material having a composition according to Formula 1:
Li a Ni x Co y A z O 2+b Formula 1
in which:
A is one or more of Al, V, Ti, B, Zr, Cu, Sn, Cr, Fe, Ga, Si, Zn, Mg, Sr, Mn, Ca, S, Ce, La, Mo, Nb, P, Sb, and W;
0.8<a<1.2
0.5<x≤1
0<y<0.5
0<z<0.2
0.2<b≤ 0.2
x+y+z=1
the process comprising the steps of:
(i) providing nickel metal precursor particles in the form of secondary particles comprising a plurality of primary particles;
(ii) providing a coating liquid comprising a metal-containing compound and a lithium-containing compound;
(iii) adding the coating liquid to the nickel metal precursor particles using an incipient wetness process to form an impregnated powder;
(iv) calcining the impregnated powder to form the surface-modified particulate lithium nickel metal oxide material.
2 . The, process according to claim 1 wherein A is one or more of Al, V, Ti, B, Zr, Cu, Sn, Cr, Fe, Ga, Si, Zn, Mg, Sr, Mn, and Ca.
3 . The, process according to claim 1 , wherein the incipient wetness process comprises the addition of the coating liquid in a volume corresponding to 50 to 150% of the apparent pore volume of the nickel metal precursor particles.
4 . The process according to claim 1 , wherein the nickel metal precursor is a nickel metal hydroxide or oxyhydroxide precursor.
5 . The, process according to claim 1 , wherein A includes Al and/or Mg, or is A and/or Mg.
6 . The process according to claim 1 , wherein the metal-containing compound is a cobalt-containing compound.
7 . The, process according to claim 1 , wherein A includes Al and the coating liquid comprises an aluminium-containing compound.
8 . The process according to claim 1 , wherein the coating liquid comprises lithium nitrate.
9 . The, process according to claim 1 , wherein the impregnated powder is mixed with lithium hydroxide prior to calcination step (iv).
10 . The process according to claim 1 , wherein the nickel metal precursor particles are mixed with a lithium-containing compound, such as lithium hydroxide, prior to the addition of the coating liquid.
11 . The process according to claim 1 , wherein the coating liquid is provided at a temperature from 50 to 80° C.
12 . The process according to claim 1 , wherein the addition step is carried out at temperature from 40 to 80° C.
13 . The process according to claim 1 , wherein the coating liquid is formed by heating at least one hydrated metal salt.
14 . The process according to claim 1 , wherein the total molar concentration of metal in the coating liquid is et4east from 0.5 mol/L to 3 mol/L.
15 . The, process according to claim 1 , wherein the coating liquid is added to the nickel metal precursor particles by spraying the coating liquid onto the particles.
16 . The process according to claim 1 , wherein the calcination step comprises heating to a temperature from 600 to 800° C.
17 . The process according to claim 1 , wherein the volume of coating liquid added corresponds to 70 to 150% of the apparent pore volume of the nickel metal precursor particle.
18 . The process according to claim 17 , wherein the volume of coating liquid added corresponds to 100 to 150% of the apparent pore volume of the nickel metal precursor particles.
19 . The process according to claim 1 , further comprising the step of forming an electrode comprising the surface-modified lithium nickel metal oxide material.
20 . The process according to claim 19 , further comprising the step of constructing a battery or electrochemical cell including the electrode comprising the surface-modified lithium nickel metal oxide material.