Cobalt-free power battery positive electrode material as well as preparation method and application thereof

A power battery and positive electrode material technology, which is applied in the field of cobalt-free power battery positive electrode materials and its preparation, can solve the problems that restrict the expansion of nickel-cobalt-lithium manganese oxide, magnetic foreign matter is easy to exceed the standard, and the process control is difficult, so as to avoid particle surface Effects of cracking, low cost, and shortened sintering time

Active Publication Date: 2020-08-18
HUNAN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Due to the high price of metal cobalt, the cobalt-containing nickel-cobalt lithium manganese oxide material is difficult to compete with lithium iron phosphate in terms of price, which restricts the further expansion of the application of nickel-cobalt lithium manganese oxide.
[0004] The magnetic foreign matter in the positive electrode material (such as iron, zinc, chromium) will dissolve during the charging process, and gradually form dendrites in the negative electrode, causing the diaphragm to perforate, causing the battery Internal short circuit, causing the battery to self-discharge, even catch fire and explode
Lithium-ion battery cathode material manufacturers generally require that the content of magnetic foreign matter in the cathode material precursor is generally less than 50ppb, and the process control is very difficult. The magnetic foreign matter in the obtained product is easy to exceed the standard, and the safety cannot be guaranteed.

Method used

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  • Cobalt-free power battery positive electrode material as well as preparation method and application thereof
  • Cobalt-free power battery positive electrode material as well as preparation method and application thereof
  • Cobalt-free power battery positive electrode material as well as preparation method and application thereof

Examples

Experimental program
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Effect test

Embodiment 1

[0075] The preparation method of the cobalt-free power battery positive electrode material in this embodiment includes the following specific steps:

[0076] (1) Mix nickel-manganese hydroxide (the molar ratio of nickel and manganese elements is 90:10) and lithium carbonate in a molar ratio of 1:1.0, add tricobalt tetroxide at 0.05%, and add water at a solid-to-liquid ratio of 1:0.2, High energy ball milling (the ratio of ball to material is 5:1, the rotational speed of the ball mill is 1200rpm, and the milling time is 1h), stirring at 60°C to obtain the slime A;

[0077] (2) Lubricate the inner wall of the mold cavity with lithium-based grease, put the sludge A into the mold, apply a preload of 1MPa, heat from room temperature to 160°C at 0.2°C / min, and keep the temperature constant for 1h;

[0078] (3) The mixed powder is subjected to high-energy pressing, the pressing speed is 5m / s, the ratio of pressing energy to powder loading is 800:8g, and a green compact is obtained; ...

Embodiment 2

[0086] The preparation method of the cobalt-free power battery positive electrode material in this embodiment comprises the following steps:

[0087] (1) Mix nickel-manganese hydroxide (where the molar ratio of nickel and manganese is 65:35) and lithium hydroxide in a molar ratio of 1:1.2, add magnesium oxide at 1%, and add ethanol at a solid-to-liquid ratio of 1:0.6 , high-energy ball milling (ball-to-material ratio 25:1, ball mill speed 800rpm, ball milling time 5h), stirring at 95°C to obtain a slime;

[0088] (2) Use lithium-based grease to lubricate the inner wall of the mold cavity, put the mud into the mold, apply a 5MPa preload, heat from room temperature to 100°C at 3°C / min, and keep the temperature for 3h to obtain a mixed powder;

[0089] (3) The mixed powder is subjected to high-energy pressing, the pressing speed is 17m / s, the ratio of pressing energy to powder loading is 2500J: 30g, and a green compact is obtained;

[0090] (4) Heat the compact to 1000°C in an o...

Embodiment 3

[0096] The preparation method of the cobalt-free power battery positive electrode material in this embodiment comprises the following steps:

[0097] (1) Mix nickel-manganese hydroxide (the molar ratio of nickel and manganese elements is 25:75) and lithium hydroxide in a molar ratio of 1:1.1, add cerium citrate at 3%, and add at a solid-to-liquid ratio of 1:0.4 Acetone, high-energy ball milling (ball-to-material ratio 10:1, ball mill speed 1000rpm, ball milling time 3h), stirring at 80°C to obtain a sludge;

[0098] (2) Use lithium base grease to lubricate the inner wall of the mold cavity, put the mud into the mold, apply 3MPa preload, heat from room temperature to 130°C at 3°C / min, and keep the temperature for 2h to obtain the mixed powder;

[0099] (3) The mixed powder is subjected to high-energy pressing, the pressing speed is 10m / s, the ratio of pressing energy to powder loading is 1500J: 15g, and a green compact is obtained;

[0100] (4) Heat the compact to 800°C in an ...

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Abstract

The invention discloses a preparation method of a cobalt-free power battery positive electrode material. The method comprises the following steps of (1) mixing nickel-manganese hydroxide and a lithiumsource, adding a dopant and a dispersing agent, carrying out ball milling, and stirring to obtain a muddy substance A; (2) adding the muddy matter A into a mold for pre-pressing to obtain the mixed powder; (3) pressing the mixed powder to obtain a pressed blank, sintering, cooling, and applying a pulsed magnetic field to obtain a blank; (4) carrying out crushing, magnetization and magnetic separation on the blank to obtain the non-magnetic particles, adding a coating material and a dispersing agent, and carrying out ball milling and stirring to obtain a muddy material B; and (5) carrying outstatic pressure sintering on the muddy substance B, crushing and screening to obtain the cobalt-free power battery positive electrode material. When the doped material is pressed and sintered with high energy, the density of a finished product is high by utilizing the high instantaneous impact force; and by adopting the static pressure sintering coating type material, the material has very high density, and under the synergistic effect of the two materials, the overall density of the material is improved.

Description

technical field [0001] The invention belongs to the field of positive electrode materials for batteries, and in particular relates to a cobalt-free power battery positive electrode material and a preparation method and application thereof. Background technique [0002] According to data from the Ministry of Industry and Information Technology, in 2019, the production and sales of new energy vehicles were 1.242 million and 1.206 million respectively. Among them, the production and sales of pure electric vehicles were 1.02 million and 972,000 respectively. Driven by the new energy vehicle industry, the power battery industry has developed rapidly. [0003] Lithium-ion batteries are widely used in power batteries due to their advantages such as high platform voltage, high energy density, long cycle life, low self-discharge rate, no memory effect, and environmental protection. Lithium battery technology currently has different types such as lithium cobalt oxide, lithium mangane...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/04H01M4/36H01M4/58H01M10/0525
CPCH01M4/0433H01M4/0471H01M4/366H01M4/5825H01M10/0525Y02E60/10
Inventor 余海军戴宏亮
Owner HUNAN UNIV
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