Preparation method of lithium iron phosphate cathode material and lithium iron phosphate cathode material

A technology for lithium iron phosphate and positive electrode materials, applied in battery electrodes, electrical components, circuits, etc., can solve problems such as uneven distribution, affecting the quality of lithium iron phosphate materials, and agglomeration, so as to improve overall performance, avoid uneven distribution and Agglomeration, uniform distribution effect

Pending Publication Date: 2016-07-20
SHENZHEN BAK POWER BATTERY CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In terms of coated carbon, the patent with the publication number CN101546830A discloses a lithium iron phosphate material coated with carbon nanotubes (CNTs). In this method, the carbon nanotubes are directly dispersed into the reactant solution for reaction and coating. The carbon nanotube-coated lithium iron phosphate material has good rate and cycle performance; however, this method directly adds carbon nanotubes to the lithium iron phosphate reactant solution, which is prone to uneven distribution, agglomeration, etc., which affects The quality of lithium iron phosphate material

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0030] Weigh 42.8g lithium hydroxide LiOH·H 2 O, 187g iron phosphate FePO 4 2H 2 O, and 11.5g glucose C 6 h 12 o 6 ·H 2 O, put in a ball mill tank, add 500mL deionized water, and ball mill to disperse evenly. It was dried in a blast oven at 60°C for 8h, and the obtained solid was pulverized in an agate mortar, then put into a tube furnace, heated to 450°C under a nitrogen atmosphere, and then fed with 10% of the total volume of nitrogen and acetylene Acetylene gas, keep warm for 3 hours; then stop feeding acetylene, raise the temperature to 650°C, keep warm for 4 hours, and get LiFePO after cooling at room temperature 4 / CNT / C composite lithium iron phosphate cathode material.

[0031] It has been determined that the carbon content of the lithium iron phosphate cathode material prepared in this example is 5.1%, and the carbon nanotubes, coated carbon and lithium iron phosphate are uniformly dispersed. The lithium iron phosphate cathode material prepared in this example...

Embodiment 2

[0033] Weigh 42.8g lithium hydroxide LiOH·H 2 O, 187g iron phosphate FePO 4 2H 2 O, and 11.5g lactose C 6 h 12 o 6 ·H 2O, put in a ball mill tank, add 500mL deionized water, and ball mill to disperse evenly. Dry it in a blast drying oven at 60°C for 8 hours, and pulverize the obtained solid in an agate mortar; then put it into a tube furnace, raise the temperature to 400°C under a nitrogen atmosphere, and then feed 10% of the total volume of nitrogen and acetylene into acetylene Gas, keep warm for 3 hours; then stop feeding acetylene, heat up to 650°C, keep warm for 4 hours, and get LiFePO after cooling at room temperature 4 / CNT / C composite lithium iron phosphate cathode material. The preparation of the button battery and the electrochemical performance test are the same as in Example 1; the test results show that the positive electrode material of this example has a 0.1C initial gram capacity of 167mAh / g, which is close to the theoretical gram capacity of 170mAh / g, an...

Embodiment 3

[0035] Weigh 40g nano iron oxide Fe 2 o 3 , 187g iron phosphate FePO 4 2H 2 O, 59g lithium phosphate Li 3 PO 4 , and 14g glucose C 6 h 12 o 6 ·H 2 O, put it in a ball mill jar, add 500mL of ethanol, disperse evenly by ball milling, dry it in a blast drying oven at 60°C for 8 hours, and pulverize the obtained solid in an agate mortar. Then put it into a tube furnace, raise the temperature to 450°C under a nitrogen atmosphere, then feed acetylene gas accounting for 10% of the total volume of nitrogen and acetylene, and keep warm for 3 hours; then stop feeding acetylene, heat up to 650°C, and keep warm for 4 hours, then LiFePO was obtained after cooling at room temperature 4 / CNT / C composite lithium iron phosphate cathode material. The preparation and electrochemical performance test of the button cell are the same as in Example 1. The test results show that the positive electrode material of this example has a 0.1C initial gram capacity of 164mAh / g, a 1C discharge gra...

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PUM

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Abstract

The invention discloses a preparation method of a lithium iron phosphate cathode material and the lithium iron phosphate cathode material. The preparation method comprises the steps as follows: lithium iron phosphate is prepared by a solid-phase synthesis method; the solid-phase synthesis method comprises ball-mill mixing and high-temperature calcination; acetylene is introduced into an inert atmosphere during calcination; and carbon nano tubes are formed in generated lithium iron phosphate particles and among the lithium iron phosphate particles to obtain the lithium iron phosphate cathode material with high conductivity. According to the preparation method, a chemical vapor deposition method for the carbon nano tubes is ingeniously combined with the solid-phase synthesis method of the lithium iron phosphate; the carbon nano tubes are gradually deposited on the surfaces of the lithium iron phosphate particles along with synthesis of the lithium iron phosphate during high-temperature calcination; a three-dimensional conductive path is formed in the particles and among the particles; and the conductivity of the cathode material is improved. According to the method, the lithium iron phosphate and the carbon nano tubes are crossly generated in a same reaction container, so that the process is simplified; the carbon nano tubes are evenly distributed; and the quality of the lithium iron phosphate cathode material is improved.

Description

technical field [0001] The present application relates to the field of preparation of positive electrode materials for lithium ion batteries, in particular to a method for preparing a lithium iron phosphate positive electrode material, and the prepared lithium iron phosphate positive electrode material. Background technique [0002] LiFePO 4 It is a positive electrode material widely used in lithium-ion batteries. 1997LiFePO 4 It has been proposed to be used in cathode materials, and has broad application prospects due to its wide source of raw materials, low price, environmental friendliness, stable material structure, good chemical compatibility, and outstanding cycle stability. [0003] However, pure LiFePO 4 There are two obvious shortcomings in the material, one is its low electrical conductivity, which makes it poor in high-rate charge and discharge performance, and it is difficult to adapt to high-current conditions, which is not conducive to the application in pow...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01M4/58
CPCY02E60/10
Inventor 滕晓波
Owner SHENZHEN BAK POWER BATTERY CO LTD
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