Embodiments of the present disclosure disclose a low-cost alkaline secondary battery positive electrode material and a preparation method and application thereof, which belongs to the technical field of alkaline secondary battery. The positive electrode material includes a composite positive electrode material including manganese dioxide and partially oxidized layered hydroxide, etc. The composite positive electrode material prepared by the embodiments of the present disclosure has the advantage of a high discharge platform, or the like, with respect to a conventional manganese electrode, which significantly improves the cycling stability and reversibility of the zinc-manganese alkaline secondary battery.

Embodiments of the present disclosure disclose a low-cost alkaline secondary battery positive electrode material and a preparation method and application thereof, which belongs to the technical field of alkaline secondary battery. The positive electrode material includes a composite positive electrode material including manganese dioxide and partially oxidized layered hydroxide, etc. The composite positive electrode material prepared by the embodiments of the present disclosure has the advantage of a high discharge platform, or the like, with respect to a conventional manganese electrode, which significantly improves the cycling stability and reversibility of the zinc-manganese alkaline secondary battery.

Disclosed herein is a process for making a particulate (oxy)hydroxide of TM where TM refers to a combination of nickel and at least one metal selected from Co and Mn and where the process includes the steps of: (a) providing one or more aqueous solution(s) () containing water-soluble salts of Ni and of at least one transition metal selected from Co and Mn, and, optionally, at least one further metal selected from Ti, Zr, Mo, W, Al, Mg, Nb, and Ta, and an aqueous solution () containing an alkali metal hydroxide and, optionally, an aqueous solution () containing a complexing agent, and (b) combining in a stirred tank reactor solution(s) () and solution () and, if applicable, solution () in one or more sub-steps, at a pH value in the range of from 10.5 to 12.5 determined at 23 C., thereby creating solid particles of hydroxide, the solid particles being slurried, where the stirred tank reactor used in step (b) or in at least one of the sub-steps (b) is equipped with a solid-liquid separation device through which mother liquor containing in the range of from 2 mg/l to 20 g/l of slurried particles of hydroxide is withdrawn.

Disclosed herein is a process for making a particulate (oxy)hydroxide of TM where TM refers to a combination of nickel and at least one metal selected from Co and Mn and where the process includes the steps of: (a) providing one or more aqueous solution(s) () containing water-soluble salts of Ni and of at least one transition metal selected from Co and Mn, and, optionally, at least one further metal selected from Ti, Zr, Mo, W, Al, Mg, Nb, and Ta, and an aqueous solution () containing an alkali metal hydroxide and, optionally, an aqueous solution () containing a complexing agent, and (b) combining in a stirred tank reactor solution(s) () and solution () and, if applicable, solution () in one or more sub-steps, at a pH value in the range of from 10.5 to 12.5 determined at 23 C., thereby creating solid particles of hydroxide, the solid particles being slurried, where the stirred tank reactor used in step (b) or in at least one of the sub-steps (b) is equipped with a solid-liquid separation device through which mother liquor containing in the range of from 2 mg/l to 20 g/l of slurried particles of hydroxide is withdrawn.

A positive electrode active material for a lithium-ion secondary battery, containing, as a main component, a lithium transition metal composite oxide that is in a form of a particle having an outer layer on a surface thereof, and is represented by:

##STR00001## where 0.95x1.05, 0.78y0.95, 0.01z0.15, and 0.01w0.15, and x+y+z+w=2, a ratio between a ratio of the number of atoms of Fe to that of Ni in the outer layer and a ratio of the number of atoms of Fe to that of Ni in the entire particle is 0.7 to 1.7, inclusive and a ratio (I.sub.1/I.sub.2) between integrated intensities (I.sub.1) and (I.sub.2) of diffraction peaks of a 003 plane and a 104 plane, respectively, in a space group R-3m is 1.15 to 1.35, inclusive.

A positive electrode active material for a lithium-ion secondary battery, containing, as a main component, a lithium transition metal composite oxide that is in a form of a particle having an outer layer on a surface thereof, and is represented by:

##STR00001## where 0.95x1.05, 0.78y0.95, 0.01z0.15, and 0.01w0.15, and x+y+z+w=2, a ratio between a ratio of the number of atoms of Fe to that of Ni in the outer layer and a ratio of the number of atoms of Fe to that of Ni in the entire particle is 0.7 to 1.7, inclusive and a ratio (I.sub.1/I.sub.2) between integrated intensities (I.sub.1) and (I.sub.2) of diffraction peaks of a 003 plane and a 104 plane, respectively, in a space group R-3m is 1.15 to 1.35, inclusive.

A metal composite compound includes at least Ni. In a scatter plot obtained by measuring a powder of the metal composite compound using a scanning electron microscope-energy dispersive X-ray spectroscopy, with a horizontal axis representing a projected area circle equivalent diameter (m) of particles of the metal composite compound and a vertical axis representing an Ni content ratio (mol %) of the particles of the metal composite compound, a slope S of an approximate straight line calculated by a least squares method is 0.2 or more and 0.2 or less. When a particle diameter at which a cumulative volume ratio from a small particle side in a volume-based particle size distribution reaches 10% is defined as D.sub.10 (m), a standard deviation X of the Ni content ratio (mol %) in particles having a projected area circle equivalent diameter of the D.sub.10 (m) or less is 2.0 mol % or less.

A metal composite compound includes at least Ni. In a scatter plot obtained by measuring a powder of the metal composite compound using a scanning electron microscope-energy dispersive X-ray spectroscopy, with a horizontal axis representing a projected area circle equivalent diameter (m) of particles of the metal composite compound and a vertical axis representing an Ni content ratio (mol %) of the particles of the metal composite compound, a slope S of an approximate straight line calculated by a least squares method is 0.2 or more and 0.2 or less. When a particle diameter at which a cumulative volume ratio from a small particle side in a volume-based particle size distribution reaches 10% is defined as D.sub.10 (m), a standard deviation X of the Ni content ratio (mol %) in particles having a projected area circle equivalent diameter of the D.sub.10 (m) or less is 2.0 mol % or less.

A metal composite compound includes at least Ni. In a scatter plot obtained by measuring a powder of the metal composite compound using a scanning electron microscope-energy dispersive X-ray spectroscopy, with a horizontal axis representing a projected area circle equivalent diameter (m) of particles of the metal composite compound and a vertical axis representing an Ni content ratio (mol %) of the particles of the metal composite compound, a slope S of an approximate straight line calculated by a least squares method is more than 0.2. When a particle diameter at which a cumulative volume ratio from a small particle side in a volume-based particle size distribution reaches 10% is defined as D.sub.10 (m), a standard deviation X of the Ni content ratio (mol %) in particles having a projected area circle equivalent diameter of the D.sub.10 (m) or less is 1.6 mol % or more.

A metal composite compound includes at least Ni. In a scatter plot obtained by measuring a powder of the metal composite compound using a scanning electron microscope-energy dispersive X-ray spectroscopy, with a horizontal axis representing a projected area circle equivalent diameter (m) of particles of the metal composite compound and a vertical axis representing an Ni content ratio (mol %) of the particles of the metal composite compound, a slope S of an approximate straight line calculated by a least squares method is more than 0.2. When a particle diameter at which a cumulative volume ratio from a small particle side in a volume-based particle size distribution reaches 10% is defined as D.sub.10 (m), a standard deviation X of the Ni content ratio (mol %) in particles having a projected area circle equivalent diameter of the D.sub.10 (m) or less is 1.6 mol % or more.