Preparation method for lithium ion secondary battery positive pole active substance lithium iron phosphate

A positive electrode active material, lithium iron phosphate technology, applied in battery electrodes, chemical instruments and methods, circuits, etc., can solve the problems of low battery capacity and poor cycle performance

Inactive Publication Date: 2008-07-02
BYD CO LTD
View PDF2 Cites 9 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to overcome the defects of low battery capacity and poor cycle performance of lithium iron phosphate prepared by the prior art, and to provide a preparation of lithium iron phosphate that makes the battery have high capacity and good cycle performance method

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Preparation method for lithium ion secondary battery positive pole active substance lithium iron phosphate
  • Preparation method for lithium ion secondary battery positive pole active substance lithium iron phosphate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] This embodiment illustrates the preparation of the positive electrode active material lithium iron phosphate provided by the invention

[0030] (1) 46.92 grams of Li 2 CO 3 , 45.69 grams of FeC 2 o 4 2H 2 O, 152.93 g FePO 4 , 29.22 g NH 4 h 2 PO 4 Mix with glucose and 350 ml of absolute ethanol (Li:Fe:P molar ratio is 1:1:1), ball mill at 300 rpm for 20 hours, take it out, and dry at 70°C;

[0031] (2) Under the protection of argon gas with a flow rate of 10 liters / minute, the mixture in step (1) was heated to 700° C. for sintering at a constant temperature at a rate of 2° C. / minute for 18 hours, cooled to room temperature naturally, and then jet crushed. Obtain lithium iron phosphate lithium ion secondary battery cathode active material; the amount of glucose so that the carbon content in the generated lithium iron phosphate is 5% by weight. The tap density of the lithium ferrous phosphate is 1.28 g / ml, and the median particle diameter D 50 is 4.3 microns.

...

Embodiment 2

[0034] This embodiment illustrates the preparation of the positive electrode active material lithium iron phosphate provided by the invention

[0035] (1) 46.92 grams of Li 2 CO 3 , 18.29 g FeC 2 o 4 2H 2 O, 172.09 g FePO 4 , 14.61 g NH 4 h 2 PO 4 and glucose 3.81 g SnO 2 Mix it with 350 ml of absolute ethanol (the molar ratio of Li:Fe:Sn:P is 1:0.98:0.02:1), ball mill at 300 rpm for 20 hours, take it out, and dry it at 70°C;

[0036] (2) Under the protection of argon gas with a flow rate of 10 liters / min, the mixture in step (1) was heated to 750° C. for sintering at a constant temperature of 1° C. / min at a rate of 1° C. / min, and was sintered at a constant temperature for 15 hours, naturally cooled to room temperature, and then airflow pulverized, Obtain lithium iron phosphate lithium ion secondary battery cathode active material; the amount of glucose so that the carbon content in the generated lithium iron phosphate is 4% by weight. The tap density of the lithium ...

Embodiment 3

[0038] This embodiment illustrates the preparation of the positive electrode active material lithium iron phosphate provided by the invention

[0039] (1) 46.92 grams of Li 2 CO 3 , 21.24 g Fe 3 (PO 4 ) 2 ·8H 2 O, 172.09 g FePO 4 , 4.87 g NH 4 h 2 PO 4 Mix it with sucrose and 250 ml of absolute ethanol (Li:Fe:P molar ratio is 1:1:1), ball mill at 300 rpm for 20 hours, take it out, and dry it at 70°C;

[0040] (2) Under the protection of argon gas with a flow rate of 10 liters / min, the mixture in step (1) was heated to 800° C. for sintering at a constant temperature of 3° C. / min for 15 hours, cooled to room temperature naturally, and then jet crushed. Obtain lithium iron phosphate lithium ion secondary battery cathode active material; the amount of the sucrose so that the carbon content in the generated lithium iron phosphate is 3% by weight. The tap density of the lithium ferrous phosphate is 1.22 g / ml, and the median particle diameter D 50 is 4.2 microns.

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

PropertyMeasurementUnit
particle sizeaaaaaaaaaa
particle sizeaaaaaaaaaa
particle sizeaaaaaaaaaa
Login to view more

Abstract

The invention relates to a preparation method of lithium iron phosphate, an active substance applied in anode of lithium-ion secondary batteries. The method comprises that a mixture that contains lithium compound, iron compound, phosphorus compound and carbon source additive is sintered, cooled to obtain sintering product; wherein, the iron compound comprises ferrous iron compound and ironic phosphate; the sintering method is one-time sintering which is carried out at constant temperature in inert atmosphere or reducing atmosphere. The lithium iron phosphate acquired by the method of the invention has good appearance, small grain size and big tap density, and batteries made of the lithium iron phosphate have high capacity and good cycling performance.

Description

technical field [0001] The present invention relates to a preparation method of a positive electrode active material of a battery, more specifically, to a preparation method of lithium iron phosphate, a positive electrode active material of a lithium ion secondary battery. Background technique [0002] As a high-energy chemical power source, lithium-ion batteries have been widely used in mobile communications, notebook computers, video cameras, cameras, portable instruments and other fields. . LiFePO 4 It is a research hotspot of positive electrode active materials for lithium-ion batteries. LiFePO 4 As a positive electrode active material for lithium-ion batteries, compared with other batteries, it has good electrochemical performance, the charging and discharging platform is very stable, and the structure is stable during charging and discharging. The advantages of use and wide range of raw material sources are currently hot spots in the battery industry's development ...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C01B25/45H01M4/58
CPCY02E60/10
Inventor 冯克光程堂利田野
Owner BYD CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap