Method for making precursors of cathode active materials for lithium ion batteries
Disclosed herein is a process for making a particulate (oxy)hydroxide of TM, where TM represents a combination of metals and includes nickel and at least one metal selected from cobalt and aluminum and manganese. The process includes: (a) combining an aqueous slurry of metallic nickel and at least one metal selected from aluminum and transition metals other than nickel with an oxidant selected from oxygen and nitrate in a first reaction vessel or in a first group of reaction vessels at a temperature of from 5° to 40° C., (b) transferring aqueous reaction medium from the first reaction vessel to a second reaction vessel, where the second reaction vessel contains a slurry of a hydroxide of TM, (c) removing the particles from step (b) from the liquid by a solid-liquid separation method, and drying the particles, and (d) returning liquid phase obtained in step (c) to the first reaction vessel.
1 . A particulate (oxy)hydroxide of TM selected from the group consisting of hydroxides and oxyhydroxides of TM, wherein TM comprises nickel and at least one metal selected from the group consisting of cobalt and manganese and aluminum, and wherein said particulate (oxy)hydroxide of TM further comprises 0.1 mol-% to 10 mol-% referring to TM of metal of TM in an oxidation state of zero, wherein the particulate (oxy)hydroxide of TM is comprised of secondary particles that are each individually composed of primary particles, and wherein the metal of TM in the oxidation state of zero is incorporated in the particulate (oxy)hydroxide of TM in the form of particles having a maximum size of the particulate (oxy)hydroxide itself.
2 . The particulate (oxy)hydroxide according to claim 1 comprising 0.1 mol-% to 10 mol-% of metal in the oxidation state zero, wherein said metal is nickel, and wherein the percentages refer to TM.
3 . A process for making a particulate (oxy)hydroxide of TM, of claim 1 wherein said process comprises the steps of:
(a) combining an aqueous slurry of metallic nickel and at least one metal selected from the group consisting of aluminum and transition metals other than nickel in the presence of ammonia with an oxidant selected from the group consisting of oxygen and nitrate in a first reaction vessel or in a first group of reaction vessels at a temperature of from 5° C. to 40° C.,
(b) transferring aqueous reaction medium from step (a) to a second reaction vessel, wherein said second reaction vessel contains a slurry of a hydroxide of TM, wherein a pH value in step (b) is higher than a pH value in step (a) and a temperature is in a range of from 45° C. to 80° C., thereby forming and growing particles of hydroxide of TM,
(c) removing the particles from step (b) from the liquid by a solid-liquid separation method, and drying the particles, and
(d) returning liquid phase obtained in step (c) to the first reaction vessel.
4 . The process according to claim 3 , wherein the particulate (oxy)hydroxide is selected from the group consisting of hydroxides and oxyhydroxides of TM, wherein TM is a combination of metals according to general formula (I)
with
a being in a range of from 0.6 to 0.95,
b being in a range of from zero to 0.2,
c being in a range of from zero to 0.2,
d being in a range of from zero to 0.1,
M is selected from the group consisting of Mg, Al, Ti, Zr, Mo, W, Al, Mg, Nb, and Ta,
a
+
b
+
c
=
1
,
and
c
+
d
>
zero
.
5 . The process according to claim 3 , wherein step (a) is performed in a presence of a complexing agent selected from the group consisting of ammonia, borate, polyborate, glycine, tartrate, citrate, and oxalate.
6 . The process according to claim 4 , wherein M is Al, and wherein zero<c≤0.1.
7 . The process according to claim 3 , wherein between steps (a) and (b), metal particles are removed from the aqueous reaction medium of step (a) by filtration or sedimentation or magnetic separation and returned to the first reaction vessel.
8 . The process according to claim 3 , wherein step (b) is performed under an atmosphere that contains up to 500 ppm O 2 .
9 . The process according to claim 3 , wherein step (a) is performed in an absence of oxygen.
10 . The process according to claim 3 , wherein in step (b), a compound of manganese or aluminum is added.
11 . The process according to claim 3 , wherein in step (d), 80 vol.-% to 95 vol.-% of the liquid phase from step (c) is returned to the first reaction vessel.
12 . The process according to claim 3 , wherein steps (a) and (b) are both performed without addition of alkali metal hydroxide.
13 . The process according to claim 3 , wherein the pH value in step (a) is in a range of from 7.0 to 10.0, and wherein the pH value in step (b) is in a range of from 9.0 to 13.0.