Spherical aluminum-doped nickel cobalt lithium for lithium ion battery and its making method

Abstract

The invention discloses a preparation method of a spherical doped Al-Ni lithium cobalt oxide for lithium-ion battery. The preparation steps are that: first, sulfate, nitrate or chlorate of Al-Ni-Co react with strong alkali that is added with complex agent in liquid phase; the pH value, the temperature and the feeding speed of the reaction solution are controlled so as to produce a spherical precursor of Al-Ni-Co hydroxide; then the spherical precursor of Al-Ni-Co hydroxide is dried and evenly mixed with lithium hydroxide, lithium nitrate or lithium carbonate and dried; the obtained mixture is roasted into a spherical doped Al-Ni lithium cobalt oxide. The spherical doped Al-Ni lithium cobalt oxide has comparatively high tap density and remarkable cycle stability in the process of high-rate charge / discharge cycle, which improves over charge performance of Ni-Co substance and first obviously enhances charge / discharge efficiency; in addition, the preparation method of the spherical doped Al-Ni lithium cobalt oxide has the advantages of being simple, controllable and suitable for industrialized production with low energy consumption, high efficiency, short reaction time and low cost.

Description

Technical field:

[0001] The invention relates to the field of secondary batteries, in particular to a spherical aluminum-nickel-doped lithium cobaltate lithium ion battery positive electrode material and a preparation method thereof. Background technique:

[0002] At present, lithium-ion batteries have been widely used in various mobile electronic appliances, such as mobile phones, cameras, notebook computers, etc. In order to adapt to the rapid development of these The demand for ion secondary batteries continues to increase. LiNiO 2 The positive electrode material doped with Co element also has LiNiO 2 The higher discharge specific capacity of the material stabilizes the layered structure of the material and enhances the cycle stability of the material. However, this material also has defects such as poor overcharge resistance, poor thermal stability, and high irreversible capacity for the first discharge. In order to solve the above problems and make nickel-cobalt mat...

Examples

example 1

[0024] First, nickel nitrate, cobalt nitrate and aluminum nitrate were mixed in a molar ratio of 0.8:0.15:0.05 to prepare a 2M aqueous solution, sodium hydroxide was prepared to 2L of a 6M solution, and 0.4L of 1M ammonia water was added. Then the prepared salt solution is added into a 10L reaction kettle filled with 2000ml 0.5M sodium carbonate aqueous solution at a flow rate of 0.5L / h, stirred and heated to 25°C, and the feed rate of the prepared alkali solution is adjusted to control the reaction The pH value of the system is between 10.0 and 10.2. After 24 hours, the particle size of the precursor in the solid-liquid mixture reaches 12.077. After the feeding is completed, the spherical aluminum-nickel-cobalt-doped lithium precursor is separated. The electron microscope photo is as follows image 3 shown. Then the prepared precursor was washed and filtered with deionized water, and then dried at 120° C. for 24 h. Lithium hydroxide and the precursor were mixed evenly at a r...

example 2

[0027] According to the method of Example 1, the precursor of aluminum-doped nickel-cobalt hydroxide was prepared and mixed with lithium salt, and the temperature was controlled at 750° C. for 24 hours. After cooling, it was crushed and classified to obtain a spherical aluminum-nickel-cobaltate lithium material.

[0028] After inspection, the aluminum-nickel-cobalt oxide has a tap density of 2.12g / cm3, a particle size of 9.421μm, an initial capacity of 181mAh / g, a 100-cycle capacity retention rate of 84%, and an initial charge-discharge efficiency of 91%.

example 3

[0030] According to the method of Example 1, the precursor of aluminum-doped nickel-cobalt hydroxide was prepared and mixed with lithium salt, and the temperature was controlled at 800° C. for 24 hours. After cooling, it was crushed and classified to obtain a spherical aluminum-nickel-cobaltate lithium material.

[0031] After inspection, the aluminum-nickel-cobalt oxide has a tap density of 2.21g / cm3, a particle size of 10.215μm, an initial capacity of 171mAh / g, a 100-cycle capacity retention rate of 83%, and an initial charge-discharge efficiency of 84%.

Technical field:

[0001] The invention relates to the field of secondary batteries, in particular to a spherical aluminum-nickel-doped lithium cobaltate lithium ion battery positive electrode material and a preparation method thereof. Background technique:

[0002] At present, lithium-ion batteries have been widely used in various mobile electronic appliances, such as mobile phones, cameras, notebook computers, etc. In order to adapt to the rapid development of these The demand for ion secondary batteries continues to increase. LiNiO 2 The positive electrode material doped with Co element also has LiNiO 2 The higher discharge specific capacity of the material stabilizes the layered structure of the material and enhances the cycle stability of the material. However, this material also has defects such as poor overcharge resistance, poor thermal stability, and high irreversible capacity for the first discharge. In order to solve the above problems and make nickel-cobalt mat...

Examples

example 1

[0024] First, nickel nitrate, cobalt nitrate and aluminum nitrate were mixed in a molar ratio of 0.8:0.15:0.05 to prepare a 2M aqueous solution, sodium hydroxide was prepared to 2L of a 6M solution, and 0.4L of 1M ammonia water was added. Then the prepared salt solution is added into a 10L reaction kettle filled with 2000ml 0.5M sodium carbonate aqueous solution at a flow rate of 0.5L / h, stirred and heated to 25°C, and the feed rate of the prepared alkali solution is adjusted to control the reaction The pH value of the system is between 10.0 and 10.2. After 24 hours, the particle size of the precursor in the solid-liquid mixture reaches 12.077. After the feeding is completed, the spherical aluminum-nickel-cobalt-doped lithium precursor is separated. The electron microscope photo is as follows image 3 shown. Then the prepared precursor was washed and filtered with deionized water, and then dried at 120° C. for 24 h. Lithium hydroxide and the precursor were mixed evenly at a r...

example 2

[0027] According to the method of Example 1, the precursor of aluminum-doped nickel-cobalt hydroxide was prepared and mixed with lithium salt, and the temperature was controlled at 750° C. for 24 hours. After cooling, it was crushed and classified to obtain a spherical aluminum-nickel-cobaltate lithium material.

[0028] After inspection, the aluminum-nickel-cobalt oxide has a tap density of 2.12g / cm3, a particle size of 9.421μm, an initial capacity of 181mAh / g, a 100-cycle capacity retention rate of 84%, and an initial charge-discharge efficiency of 91%.

example 3

[0030] According to the method of Example 1, the precursor of aluminum-doped nickel-cobalt hydroxide was prepared and mixed with lithium salt, and the temperature was controlled at 800° C. for 24 hours. After cooling, it was crushed and classified to obtain a spherical aluminum-nickel-cobaltate lithium material.

[0031] After inspection, the aluminum-nickel-cobalt oxide has a tap density of 2.21g / cm3, a particle size of 10.215μm, an initial capacity of 171mAh / g, a 100-cycle capacity retention rate of 83%, and an initial charge-discharge efficiency of 84%.

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