Core-shell structured lithium nickel manganese cobalt precursor, fabrication method thereof and application thereof in lithium ion battery

Abstract

The invention relates to a core-shell structured lithium nickel manganese cobalt precursor, a fabrication method thereof and application thereof in a lithium ion battery. The precursor is nickel manganese cobalt carbonate and sequentially comprises an inner core and more than one shell layer from inside to outside, and mole concentration of the corresponding Ni is gradually reduced from the innercore to the shell layers sequentially arranged outside. The invention also provides a surface coated lithium nickel manganese cobalt composite material prepared by employing the precursor and the lithium ion battery employing the composite material as a positive electrode material. By the precursor, the problems that the synthesis process of a ternary nickel manganese cobalt positive electrode material is not mature and is complicated, the precursor research is neglected and the improvement of the performance of the ternary nickel manganese cobalt material is limited are solved. In the batteryprepared from a nickel-rich gradient-concentration ternary nickel manganese cobalt positive electrode material, the initial discharge specific capacity under 0.1C rate is larger 194mAh / g, the initialcharge-discharge efficiency is larger than 92%, and the capacity retention rate after circulation for 300 times under 1C rate is larger than 80%.

Description

technical field

[0001] The invention belongs to the field of lithium-ion batteries and lithium-ion battery cathode materials, and relates to a nickel-cobalt-lithium manganese oxide precursor with a core-shell structure, its preparation method and its application in lithium-ion batteries, in particular to a nickel-cobalt with a core-shell structure A lithium manganate precursor, a surface-coated nickel-cobalt lithium manganese oxide composite material prepared by using the precursor, and a lithium ion battery containing the composite material as a positive electrode material. Background technique

[0002] The global energy crisis and environmental pollution are becoming more and more serious. Advanced lithium-ion battery cathode materials constitute the core technology for the current lithium-ion battery replacement. It is urgent to develop low-cost, high-performance lithium-ion battery cathode materials in the development of the national economy and society. One of the key s...

Examples

Embodiment 1

[0102] 1. Preparation of nickel-cobalt-manganese carbonate precursor with core-shell structure

[0103] (1) Weigh the sulfate salt of nickel, cobalt, manganese, be mixed with the mixed salt solution A that concentration is 2.5mol / L according to Ni, Co, M molar ratio is 8:1:1, mix solution A, precipitant Na 2 CO 3 solution, complexing agent sodium acetate solution, under continuous stirring, flow into the reactor, so that Ac - :(Ni+Mn+Co)=1:1, Na 2 CO 3 The concentration of the solution is 2.5mol / L, adding the pH regulator NH 4 HCO 3 Solution, the pH value of the solution was adjusted to 8.5, and the inner core precursor slurry M1 was obtained by a controlled crystallization precipitation method.

[0104] (2) Weigh the sulfate salt of nickel, cobalt and manganese, according to Ni, Co, M molar ratio is 6:2:2, be mixed with the mixed salt solution B that concentration is 3.0mol / L, solution B, precipitant Na 2 CO 3 Solution, complexing agent sodium acetate solution, under c...

Embodiment 2

[0117] Except the following content, other methods and conditions are identical with embodiment 1:

[0118] When preparing the core-shell structure nickel-cobalt-manganese carbonate precursor, in the step (1), according to Ni, Co, M molar ratio is 7:1:1 to be mixed with the mixed salt solution A that concentration is 2.5mol / L; Step (2 ) in according to Ni, Co, M molar ratio is 5:3:2, is mixed with the mixed salt solution B that concentration is 3.0mol / L;

[0119] When preparing the nitrogen-doped M element oxide, M=Ce, and the particle size of the cerium oxide is 20nm, and the doping amount of nitrogen in the cerium oxide is 1wt%.

[0120] When preparing the surface-coated nickel-cobalt lithium manganese oxide positive electrode material, in the first coating, the ratio of the total amount of zirconia and titanium oxide to the total amount of nickel, cobalt, and manganese is 0.001:1; The drying temperature is 105°C; the calcination temperature is 950°C, and the calcination ti...

Embodiment 3

[0124] Except the following content, other methods and conditions are identical with embodiment 1:

[0125] When preparing the core-shell structure nickel-cobalt-manganese carbonate precursor, in the step (1), according to Ni, Co, M molar ratio is 7.5:1:1 to be mixed with the mixed salt solution A that concentration is 2.5mol / L; Step (2 ) in according to Ni, Co, M molar ratio is 4:3:3, is mixed with the mixed salt solution B that concentration is 3.0mol / L;

[0126] When preparing the nitrogen-doped M element oxide, M=Mg, and the particle size of the magnesium oxide is 85nm, and the doping amount of nitrogen in the magnesium oxide is 0.5wt%.

[0127] When preparing the surface-coated nickel-cobalt lithium manganese oxide positive electrode material, in the first coating, the ratio of the total amount of zirconia and titanium oxide to the total amount of nickel, cobalt, and manganese is 0.1:1; microwave The drying temperature is 80°C; the calcination temperature is 550°C, and t...

technical field

[0001] The invention belongs to the field of lithium-ion batteries and lithium-ion battery cathode materials, and relates to a nickel-cobalt-lithium manganese oxide precursor with a core-shell structure, its preparation method and its application in lithium-ion batteries, in particular to a nickel-cobalt with a core-shell structure A lithium manganate precursor, a surface-coated nickel-cobalt lithium manganese oxide composite material prepared by using the precursor, and a lithium ion battery containing the composite material as a positive electrode material. Background technique

[0002] The global energy crisis and environmental pollution are becoming more and more serious. Advanced lithium-ion battery cathode materials constitute the core technology for the current lithium-ion battery replacement. It is urgent to develop low-cost, high-performance lithium-ion battery cathode materials in the development of the national economy and society. One of the key s...

Examples

Embodiment 1

[0102] 1. Preparation of nickel-cobalt-manganese carbonate precursor with core-shell structure

[0103] (1) Weigh the sulfate salt of nickel, cobalt, manganese, be mixed with the mixed salt solution A that concentration is 2.5mol / L according to Ni, Co, M molar ratio is 8:1:1, mix solution A, precipitant Na 2 CO 3 solution, complexing agent sodium acetate solution, under continuous stirring, flow into the reactor, so that Ac - :(Ni+Mn+Co)=1:1, Na 2 CO 3 The concentration of the solution is 2.5mol / L, adding the pH regulator NH 4 HCO 3 Solution, the pH value of the solution was adjusted to 8.5, and the inner core precursor slurry M1 was obtained by a controlled crystallization precipitation method.

[0104] (2) Weigh the sulfate salt of nickel, cobalt and manganese, according to Ni, Co, M molar ratio is 6:2:2, be mixed with the mixed salt solution B that concentration is 3.0mol / L, solution B, precipitant Na 2 CO 3 Solution, complexing agent sodium acetate solution, under c...

Embodiment 2

[0117] Except the following content, other methods and conditions are identical with embodiment 1:

[0118] When preparing the core-shell structure nickel-cobalt-manganese carbonate precursor, in the step (1), according to Ni, Co, M molar ratio is 7:1:1 to be mixed with the mixed salt solution A that concentration is 2.5mol / L; Step (2 ) in according to Ni, Co, M molar ratio is 5:3:2, is mixed with the mixed salt solution B that concentration is 3.0mol / L;

[0119] When preparing the nitrogen-doped M element oxide, M=Ce, and the particle size of the cerium oxide is 20nm, and the doping amount of nitrogen in the cerium oxide is 1wt%.

[0120] When preparing the surface-coated nickel-cobalt lithium manganese oxide positive electrode material, in the first coating, the ratio of the total amount of zirconia and titanium oxide to the total amount of nickel, cobalt, and manganese is 0.001:1; The drying temperature is 105°C; the calcination temperature is 950°C, and the calcination ti...

Embodiment 3

[0124] Except the following content, other methods and conditions are identical with embodiment 1:

[0125] When preparing the core-shell structure nickel-cobalt-manganese carbonate precursor, in the step (1), according to Ni, Co, M molar ratio is 7.5:1:1 to be mixed with the mixed salt solution A that concentration is 2.5mol / L; Step (2 ) in according to Ni, Co, M molar ratio is 4:3:3, is mixed with the mixed salt solution B that concentration is 3.0mol / L;

[0126] When preparing the nitrogen-doped M element oxide, M=Mg, and the particle size of the magnesium oxide is 85nm, and the doping amount of nitrogen in the magnesium oxide is 0.5wt%.

[0127] When preparing the surface-coated nickel-cobalt lithium manganese oxide positive electrode material, in the first coating, the ratio of the total amount of zirconia and titanium oxide to the total amount of nickel, cobalt, and manganese is 0.1:1; microwave The drying temperature is 80°C; the calcination temperature is 550°C, and t...

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