Carbon-coated ternary positive electrode material and preparation method thereof

Abstract

The invention discloses a carbon-coated ternary positive electrode material and a preparation method thereof. The preparation method comprises the following steps: S1, preparing a ternary positive electrode material precursor by taking nickel salt, cobalt salt and manganese salt as raw materials; S2, preparing a conductive carbon dispersion system, wherein conductive carbon is dispersed in water containing an organic carbon source; S3, adding the ternary positive electrode material precursor and a lithium compound into the conductive carbon dispersion system, and mixing uniformly to obtain a mixture; S4, drying the mixture under a vacuum condition; S5, carrying out high temperature treatment on the dried mixture under a closed condition or in an inert gas protection atmosphere so as to obtain the carbon-coated ternary positive electrode material. The carbon-coated ternary positive electrode material is uniform in coating, simple to operate, low in cost and high in efficiency; the conductive carbon and the ternary positive electrode material are simultaneously coated with network-shaped amorphous carbon which serves as a conductive medium or a channel of the conductive carbon and the ternary positive electrode material, thereby greatly improving the rate performance of the ternary positive electrode material.

Description

technical field

[0001] The invention relates to the technical field of lithium-ion battery materials, in particular to a method for preparing a carbon-coated ternary positive electrode material for lithium-ion batteries and the carbon-coated ternary positive electrode material. Background technique

[0002] Lithium-ion batteries have a series of advantages such as high specific energy, high working voltage, good safety, and no memory effect. They are not only widely used as power sources for portable electronic products such as notebook computers, digital cameras, mobile phones, and video cameras, but also Become one of the main power sources of electric bicycles, electric motorcycles and electric vehicles. On the one hand, this provides a broad space for the development of lithium-ion batteries; The most direct way to improve the overall performance of batteries is to improve the performance of battery materials.

[0003] As one of the core components of the battery, the ...

Examples

preparation example Construction

[0034] Such as figure 1 As shown, the preparation method of the carbon-coated ternary positive electrode material of the present invention comprises the following steps:

[0035] S1. Using nickel salt, cobalt salt and manganese salt as raw materials, prepare a precursor of ternary cathode material.

[0036] In this step S1, the nickel salt is a soluble salt such as nickel sulfate, nitrate or hydrochloride, the cobalt salt is a soluble salt such as cobalt sulfate, nitrate or hydrochloride, and the manganese salt is manganese sulfate, nitric acid Soluble salts such as salt or hydrochloride. The semi-liquid and semi-solid method is used to make the raw material into the precursor of the ternary positive electrode material; the semi-liquid and semi-solid method is to prepare a mixed solution of nickel salt, cobalt salt and manganese salt, and obtain nickel salt and cobalt salt by liquid phase precipitation method and a slurry-like mixture of manganese salt, and then adopt a low-...

Embodiment 1

[0050] S1. Prepare a mixed solution of 0.2mol / L nickel sulfate, cobalt sulfate and manganese sulfate according to the stoichiometric ratio, and prepare the precursor Ni of the ternary positive electrode material by the semi-liquid and semi-solid method 1 / 3 co 1 / 3 mn 1 / 3 (OH) 2 ;

[0051] S2. Disperse 5 grams of graphite in an aqueous solution of 500 grams of sucrose (10% by weight of sucrose) by mechanical stirring, and stir for 15 minutes to obtain a conductive carbon dispersion system;

[0052] S3, adding 125 grams of ternary positive electrode material precursor and 55 grams of lithium carbonate to the conductive carbon dispersion system, using mechanical stirring to make it evenly mixed to obtain a mixture;

[0053] S4. Dry the mixture obtained above at 50° C. under vacuum conditions for 10 hours;

[0054] S5. Treat the dried mixture at a high temperature for 15 hours in a high-temperature furnace at 500° C. and a nitrogen flow rate of 0.2 L / min to obtain a carbon-coat...

Embodiment 2

[0056] S1. Prepare a mixed solution of 0.5mol / L nickel sulfate, cobalt sulfate and manganese sulfate according to the stoichiometric ratio, and prepare the precursor Ni of the ternary cathode material by the semi-liquid and semi-solid method 1 / 3 co 1 / 3 mn 1 / 3 (OH) 2 ;

[0057] S2, adopt mechanical stirring method to disperse 4 grams of acetylene carbon black in the aqueous solution of 300 grams of glucose (the weight percent composition of glucose is 30%), stirring time is 30 minutes;

[0058] S3, adding 76 grams of ternary positive electrode material precursor and 45 grams of lithium carbonate to the conductive carbon dispersion system, using mechanical stirring to make it evenly mixed to obtain a mixture;

[0059] S4. Dry the mixture obtained above at 60°C for 5 hours under vacuum conditions;

[0060] S5. Treat the dried mixture at 800° C. in a closed high-temperature furnace for 10 hours to obtain a carbon-coated ternary positive electrode material.

technical field

[0001] The invention relates to the technical field of lithium-ion battery materials, in particular to a method for preparing a carbon-coated ternary positive electrode material for lithium-ion batteries and the carbon-coated ternary positive electrode material. Background technique

[0002] Lithium-ion batteries have a series of advantages such as high specific energy, high working voltage, good safety, and no memory effect. They are not only widely used as power sources for portable electronic products such as notebook computers, digital cameras, mobile phones, and video cameras, but also Become one of the main power sources of electric bicycles, electric motorcycles and electric vehicles. On the one hand, this provides a broad space for the development of lithium-ion batteries; The most direct way to improve the overall performance of batteries is to improve the performance of battery materials.

[0003] As one of the core components of the battery, the ...

Examples

preparation example Construction

[0034] Such as figure 1 As shown, the preparation method of the carbon-coated ternary positive electrode material of the present invention comprises the following steps:

[0035] S1. Using nickel salt, cobalt salt and manganese salt as raw materials, prepare a precursor of ternary cathode material.

[0036] In this step S1, the nickel salt is a soluble salt such as nickel sulfate, nitrate or hydrochloride, the cobalt salt is a soluble salt such as cobalt sulfate, nitrate or hydrochloride, and the manganese salt is manganese sulfate, nitric acid Soluble salts such as salt or hydrochloride. The semi-liquid and semi-solid method is used to make the raw material into the precursor of the ternary positive electrode material; the semi-liquid and semi-solid method is to prepare a mixed solution of nickel salt, cobalt salt and manganese salt, and obtain nickel salt and cobalt salt by liquid phase precipitation method and a slurry-like mixture of manganese salt, and then adopt a low-...

Embodiment 1

[0050] S1. Prepare a mixed solution of 0.2mol / L nickel sulfate, cobalt sulfate and manganese sulfate according to the stoichiometric ratio, and prepare the precursor Ni of the ternary positive electrode material by the semi-liquid and semi-solid method 1 / 3 co 1 / 3 mn 1 / 3 (OH) 2 ;

[0051] S2. Disperse 5 grams of graphite in an aqueous solution of 500 grams of sucrose (10% by weight of sucrose) by mechanical stirring, and stir for 15 minutes to obtain a conductive carbon dispersion system;

[0052] S3, adding 125 grams of ternary positive electrode material precursor and 55 grams of lithium carbonate to the conductive carbon dispersion system, using mechanical stirring to make it evenly mixed to obtain a mixture;

[0053] S4. Dry the mixture obtained above at 50° C. under vacuum conditions for 10 hours;

[0054] S5. Treat the dried mixture at a high temperature for 15 hours in a high-temperature furnace at 500° C. and a nitrogen flow rate of 0.2 L / min to obtain a carbon-coat...

Embodiment 2

[0056] S1. Prepare a mixed solution of 0.5mol / L nickel sulfate, cobalt sulfate and manganese sulfate according to the stoichiometric ratio, and prepare the precursor Ni of the ternary cathode material by the semi-liquid and semi-solid method 1 / 3 co 1 / 3 mn 1 / 3 (OH) 2 ;

[0057] S2, adopt mechanical stirring method to disperse 4 grams of acetylene carbon black in the aqueous solution of 300 grams of glucose (the weight percent composition of glucose is 30%), stirring time is 30 minutes;

[0058] S3, adding 76 grams of ternary positive electrode material precursor and 45 grams of lithium carbonate to the conductive carbon dispersion system, using mechanical stirring to make it evenly mixed to obtain a mixture;

[0059] S4. Dry the mixture obtained above at 60°C for 5 hours under vacuum conditions;

[0060] S5. Treat the dried mixture at 800° C. in a closed high-temperature furnace for 10 hours to obtain a carbon-coated ternary positive electrode material.

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