Method for producing lithium metal composite oxide
A method for producing a lithium metal composite oxide including a step of calcining, at 600° C. or higher, one of a mixture of a lithium compound and a metal composite compound containing at least Ni and a reactant obtained by preliminarily calcining the mixture to obtain a calcined product, a step of cooling the calcined product from a calcining temperature in the step of obtaining the calcined product to 150° C. or lower to obtain a cooled product, and a step of pulverizing the cooled product such that a BET specific surface area becomes 0.90 to 1.55 m 2 /g, in which, in the step of obtaining the cooled product, an average cooling rate in a temperature range from 600° C. to 150° C. is 150 to 3500° C./h.
1 . A method for producing a lithium metal composite oxide comprising:
a step of calcining, at 600° C. or higher, (a) a mixture of a lithium compound and a metal composite compound containing at least Ni, or (b) a reactant obtained by preliminarily calcining the mixture, to obtain a calcined product;
a step of cooling the calcined product from a calcining temperature in the step of obtaining the calcined product to 150° C. or lower to obtain a cooled product; and
a step of pulverizing the cooled product such that a BET specific surface area becomes 0.90 to 1.55 m 2 /g,
wherein, in the step of obtaining the cooled product, an average cooling rate in a temperature range from 600° C. to 150° C. is 150 to 3500° C./h,
an average cooling rate in a temperature range from 600° C. to 400° C. in the step of obtaining the cooled product is 243 to 7357° C./h,
an average cooling rate in a temperature range from 400° C. to 150° C. in the step of obtaining the cooled product is 10 to 3500° C./h, and
the average cooling rate in the temperature range from 600° C. to 400° C. and the average cooling rate in the temperature range from 400° C. to 150° C. are different, and
the average cooling rate in the temperature range from 400° C. to 150° C. is smaller than the average cooling rate in the temperature range from 600° C. to 400° C., and a temperature difference between the average cooling rate from 600-400° C. and the average cooling rate from 400-150° C. is 233° C./h to 3857° C./h.
2 . The method for producing the lithium metal composite oxide according to claim 1 ,
wherein the lithium metal composite oxide is represented by a composition formula (I),
Li[Li x (Ni (1-y-z) CO y X z ) 1-x ]O 2 (I)
in the formula (I), X represents one or more elements selected from the group consisting of Mn, Cu, Ti, Mg, Al, W, B, Mo, Nb, Zn, Sn, Zr, Ga, and V, and −0.1≤x≤0.2, 0≤y≤0.5, 0≤z≤0.8, and y+z<1 are satisfied.
3 . The method for producing the lithium metal composite oxide according to claim 1 ,
wherein the step of obtaining the calcined product and the step of obtaining the cooled product are performed in an oxygen-containing atmosphere.
4 . The method for producing the lithium metal composite oxide according to claim 3 ,
wherein an oxygen concentration in the oxygen-containing atmosphere in the step of obtaining the cooled product is higher than an oxygen concentration in the oxygen-containing atmosphere in the step of obtaining the calcined product.
5 . The method for producing the lithium metal composite oxide according to claim 1 ,
wherein the step of obtaining the calcined product is performed using a rotary kiln, and the step of obtaining the cooled product is performed using one of a rotary cooler and a fluidized-bed cooler.
6 . The method for producing the lithium metal composite oxide according to claim 5 ,
wherein the step of obtaining the cooled product is performed using the rotary cooler, and a ratio of a volume of a rotary cylinder of the rotary cooler to a volume of a rotary cylinder of the rotary kiln is 0.05 to 2.
7 . The method for producing the lithium metal composite oxide according to claim 6 ,
wherein a rotation speed of the rotary cooler in the step of obtaining the cooled product is 0.4 to 130 m/min.
8 . The method for producing the lithium metal composite oxide according to claim 1 ,
wherein the step of pulverizing the cooled product is performed using a disc mill or a pin mill.
9 . The method for producing the lithium metal composite oxide according to claim 8 ,
wherein, in the step of pulverizing the cooled product, the disc mill is operated such that a rotation speed becomes 120 to 12000 rpm, and the cooled product is pulverized.
10 . The method for producing the lithium metal composite oxide according to claim 8 ,
wherein, in the step of pulverizing the cooled product, the pin mill is operated such that a rotation speed becomes 300 rpm or more and less than 20000 rpm, and the cooled product is pulverized.
11 . The method for producing the lithium metal composite oxide according to claim 2 ,
wherein the step of obtaining the calcined product and the step of obtaining the cooled product are performed in an oxygen-containing atmosphere.
12 . The method for producing the lithium metal composite oxide according to claim 2 , wherein X represents one or more elements selected from the group consisting of Cu, Ti, Mg, Al, W, B, Mo, Nb, Zn, Sn, Zr, Ga, and V.
13 . The method for producing the lithium metal composite oxide according to claim 2 , wherein z=0.
14 . The method for producing the lithium metal composite oxide according to claim 1 , wherein the average cooling rate in the temperature range from 600° C. to 400° C. is 6000 to 7357° C./h.