Cathode active material and preparation method thereof, cathode material and lithium ion battery

A cathode active material, cathode material technology, applied in battery electrodes, secondary batteries, circuits, etc., can solve problems such as poor cycle performance and poor battery rate performance

Active Publication Date: 2012-07-11
BYD CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0011] In order to overcome the problems of poor rate performance and poor cycle performance of lithium-ion batteries made of positive active materials in the prior art, the invention provides a positive active material

Method used

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  • Cathode active material and preparation method thereof, cathode material and lithium ion battery
  • Cathode active material and preparation method thereof, cathode material and lithium ion battery
  • Cathode active material and preparation method thereof, cathode material and lithium ion battery

Examples

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preparation example Construction

[0032] The present invention also discloses a preparation method of the above positive electrode active material, including:

[0033] a. Mixing the lithium-rich manganese-based material with an aqueous sulfate solution to obtain a first mixture;

[0034] b. heating the first mixture, and performing heat treatment at 300-1000° C., the heat treatment time being 10-15 hours, to obtain a positive electrode active material precursor;

[0035] c. Adding the boron-containing compound and the positive electrode active material precursor into water, and mixing uniformly to obtain a second mixture;

[0036] d. The second mixture is heated and calcined at 300-1000° C. for 10-15 hours, and then the calcined product is washed, filtered and dried to obtain the positive electrode active material.

[0037] Wherein, the composition of the lithium-rich manganese-based material is as described above, and will not be repeated here. For the average particle size of the lithium-rich manganese-bas...

Embodiment 1

[0067] This example is used to illustrate the positive electrode active material disclosed in the present invention and its preparation method.

[0068] Li with an average particle size of 15.22um 1.5 mn 0.75 Ni 0.25 o 2.5 with a concentration of 50g / l MnSO 4 aqueous solution mixed to obtain the first mixture. Among them, MnSO 4 with Li 1.5 mn 0.75 Ni 0.25 o 2.5 The weight ratio is 5:100.

[0069] The first mixture was heated to 500° C. at a heating rate of 15° C. / h, and heat-treated at 500° C. for 10 hours to obtain a positive electrode active material precursor.

[0070] Add lithium borate and positive electrode active material precursor into water and mix uniformly to obtain a second mixture. Wherein, the weight ratio of lithium borate to the positive electrode active material precursor is 25:100.

[0071] The second mixture was heated to 550° C. at a heating rate of 20° C. / h, and calcined at 550° C. for 15 hours, and then the calcined product was washed, filter...

Embodiment 2

[0073] This example is used to illustrate the positive electrode active material disclosed in the present invention and its preparation method.

[0074] Li with an average particle size of 7um 1.5 mn 0.75 Ni 0.25 o 2.5 With a concentration of 200g / l (NH 4 ) 2 SO 4 aqueous solution mixed to obtain the first mixture. Among them, (NH 4 ) 2 SO 4 with Li 1.5 mn 0.75 Ni 0.25 o 2.5 The weight ratio is 15:100.

[0075] The first mixture was heated to 350° C. at a heating rate of 5° C. / h, and heat-treated at 350° C. for 10 hours to obtain a positive electrode active material precursor.

[0076] Add boric acid and positive electrode active material precursor into water and mix uniformly to obtain a second mixture. Wherein, the weight ratio of boric acid to the positive electrode active material precursor is 2:100.

[0077] The second mixture was heated to 310° C. at a heating rate of 10° C. / h, and calcined at 310° C. for 12 hours, and then the calcined product was washed...

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Abstract

The invention provides a cathode active material and a preparation method thereof, a cathode material and a lithium ion battery. The cathode active material is provided with a kernel and a shell wrapped on the surface of the kernel, wherein the kernel is made of a lithium-enriched manganese-based material; the composition of the lithium-enriched manganese-based material is Li1+xMnaMbOz, wherein x is more than or equal to 0 and less than or equal to 1, a is more than 0 and less than or equal to 2, b is more than or equal to 0 and less than or equal to 2, z is more than or equal to 2 and less than or equal to 5, and M is selected from one or more of Co, Ni, Fe, Mg, Ca, Sn, Ti, Zr, Zn and Cr; and the shell is made of boron oxide. The rate capability and the circulation performance of the lithium ion battery prepared by adopting the cathode active material are high.

Description

technical field [0001] The invention relates to a positive electrode active material and a preparation method thereof, a positive electrode material and a lithium ion battery. Background technique [0002] Lithium-ion batteries are widely used in portable electronic devices, and the core part of lithium-ion batteries is its positive electrode active material. Currently, LiCoO 2 , LiNiO 2 and LiMn 2 o 4 Considered as the most attractive cathode material, LiCoO 2 and LiNiO 2 The theoretical specific capacity of LiCoO is about 275 mAh / g, but the actual specific capacity is only about 145 mAh / g, and LiCoO 2 The material is expensive, LiNiO 2 Material preparation is more difficult, and these two materials especially LiNiO 2 Oxygen is released under high voltage, which poses a safety hazard. LiMn 2 o 4 The theoretical specific capacity is only 148 mAh / g, and the actual specific capacity is about 120 mAh / g. [0003] At present, surface coating is mainly used to improve...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/505H01M4/1391H01M10/0525
CPCY02E60/122Y02E60/10
Inventor 杨鹏巢亚军王夏芬罗倩高雪庆
Owner BYD CO LTD
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