A method for preparing a positive electrode active material precursor having a narrow particle size distribution in a reproducible manner. The method utilizes a reaction device in which a reactor and a continuous grinder are connected. The method includes the steps of: (S1) introducing a reaction solution including a transition metal-containing solution, an ammonium ion-containing solution, and a basic aqueous solution into the reactor to form and discharge a positive electrode active material precursor seed; and (S2) introducing the positive electrode active material precursor seed discharged from the reactor into the continuous grinder, and discharging and re-introducing the positive electrode active material precursor seed into the reactor. Steps (S1) and (S2) are carried out simultaneously.

A method for preparing a positive electrode active material precursor having a narrow particle size distribution in a reproducible manner. The method utilizes a reaction device in which a reactor and a continuous grinder are connected. The method includes the steps of: (S1) introducing a reaction solution including a transition metal-containing solution, an ammonium ion-containing solution, and a basic aqueous solution into the reactor to form and discharge a positive electrode active material precursor seed; and (S2) introducing the positive electrode active material precursor seed discharged from the reactor into the continuous grinder, and discharging and re-introducing the positive electrode active material precursor seed into the reactor. Steps (S1) and (S2) are carried out simultaneously.

The present disclosure relates to a method of producing particles that include first particles each having a core portion, a gap portion, and an outer portion and each made of a nickel-containing transition metal composite hydroxide. In the method of producing particles according to the present disclosure, a pH of the Taylor vortex reaction field at a liquid temperature of 25 C. is 12.5 or less, a first crystallization is performed in which the crystallization is allowed to proceed at an oxygen concentration of the Taylor vortex reaction field of 3.5 vol % or less, a second crystallization is performed in which the oxygen concentration of the Taylor vortex reaction field is changed to a range of 5 vol % to 65 vol % and the crystallization is allowed to proceed, and a duration of the first crystallization is from 40% to 90% of a total crystallization duration.

The present disclosure relates to a method of producing particles that include first particles each having a core portion, a gap portion, and an outer portion and each made of a nickel-containing transition metal composite hydroxide. In the method of producing particles according to the present disclosure, a pH of the Taylor vortex reaction field at a liquid temperature of 25 C. is 12.5 or less, a first crystallization is performed in which the crystallization is allowed to proceed at an oxygen concentration of the Taylor vortex reaction field of 3.5 vol % or less, a second crystallization is performed in which the oxygen concentration of the Taylor vortex reaction field is changed to a range of 5 vol % to 65 vol % and the crystallization is allowed to proceed, and a duration of the first crystallization is from 40% to 90% of a total crystallization duration.

A method of preparing a cathode precursor material comprising combining a Tutton's salt exhibiting the chemical formula (NH.sub.4).sub.2M(SO.sub.4).sub.2.Math.6H.sub.2O, wherein M comprises one or more metals, and water to form a Tutton's salt solution, adding a chelating agent to the Tutton's salt solution to form a Tutton's salt/chelating agent solution, and heating the Tutton's salt/chelating agent solution to form a cathode precursor material comprising a mixed metal composition of the Tutton's salt. Additional methods are disclosed.

A method of preparing a cathode precursor material comprising combining a Tutton's salt exhibiting the chemical formula (NH.sub.4).sub.2M(SO.sub.4).sub.2.Math.6H.sub.2O, wherein M comprises one or more metals, and water to form a Tutton's salt solution, adding a chelating agent to the Tutton's salt solution to form a Tutton's salt/chelating agent solution, and heating the Tutton's salt/chelating agent solution to form a cathode precursor material comprising a mixed metal composition of the Tutton's salt. Additional methods are disclosed.

The present invention relates to a metal composite compound used as a precursor of a positive electrode active material for a lithium secondary battery, said metal composite compound comprising at least one metal element selected from the group consisting of Ni, Co, and Mn, and satisfying all of the following requirements (1) to (3): (1) An average particle strength is 10 MPa or more and less than 45 MPa; (2) An average particle diameter D.sub.50 is 1.0 m or more and 4.0 m or less; (3) A BET specific surface area is 40 m.sup.2/g or more and 100 m.sup.2/g or less.

The present invention relates to a metal composite compound used as a precursor of a positive electrode active material for a lithium secondary battery, said metal composite compound comprising at least one metal element selected from the group consisting of Ni, Co, and Mn, and satisfying all of the following requirements (1) to (3): (1) An average particle strength is 10 MPa or more and less than 45 MPa; (2) An average particle diameter D.sub.50 is 1.0 m or more and 4.0 m or less; (3) A BET specific surface area is 40 m.sup.2/g or more and 100 m.sup.2/g or less.

The positive electrode active material includes a single particle composed of one single nodule, a quasi-single particle, which is a composite of at most 30 nodules, or a combination thereof. The positive electrode active material includes a lithium nickel-based oxide having a molar ratio of Ni of at least 60 mol % in the total transition metals, and a negative skewness factor (NSF) represented by Equation 1 below is 0.20 to 0.35:

[00001]$\begin{array}{cc}\mathrm{NSF}=\left(D_{50}-D_{10}\right)/I_{\max }.& \left[\mathrm{Equation}1\right]\end{array}$

D.sub.50 is a particle diameter at a cumulative volume of 50% in a volume cumulative particle size distribution graph of the positive electrode active material. D.sub.10 is a particle diameter at a cumulative volume of 10% in a volume cumulative particle size distribution graph of the positive electrode active material. I.sub.max is a maximum volume fraction in the volume cumulative particle size distribution graph of the positive electrode active material.

The positive electrode active material includes a single particle composed of one single nodule, a quasi-single particle, which is a composite of at most 30 nodules, or a combination thereof. The positive electrode active material includes a lithium nickel-based oxide having a molar ratio of Ni of at least 60 mol % in the total transition metals, and a negative skewness factor (NSF) represented by Equation 1 below is 0.20 to 0.35:

[00001]$\begin{array}{cc}\mathrm{NSF}=\left(D_{50}-D_{10}\right)/I_{\max }.& \left[\mathrm{Equation}1\right]\end{array}$

D.sub.50 is a particle diameter at a cumulative volume of 50% in a volume cumulative particle size distribution graph of the positive electrode active material. D.sub.10 is a particle diameter at a cumulative volume of 10% in a volume cumulative particle size distribution graph of the positive electrode active material. I.sub.max is a maximum volume fraction in the volume cumulative particle size distribution graph of the positive electrode active material.