Lithium iron phosphate anode material for lithium ion battery and modification method

A technology of lithium iron phosphate and cathode material, which is applied in battery electrodes, electrode manufacturing, chemical instruments and methods, etc., can solve the problems of difficulty in obtaining high-rate electrochemical performance, poor chemical uniformity of products, and deterioration of electrochemical performance, etc. Achieve the effect of solving the inconsistency between preparation conditions and modification conditions, excellent electrochemical performance, and overcoming poor repeatability

Inactive Publication Date: 2008-12-03
HEFEI UNIV OF TECH
View PDF4 Cites 24 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, in the methods reported in these literatures, due to the addition of the basic raw materials for the synthesis of lithium ferrous phosphate in the hydrothermal synthesis stage due to the doping of metal ion salts and conductive material precursors, it cannot be used with the basic raw materials for the synthesis of lithium ferrous phosphate. To avoid mutual interference and side reactions, the chemical uniformity of the product is poor, and even impurity phases will be generated, which will lead to the deterioration of the electrochemical performance of the product, and it is difficult to obtain the ideal high-rate electrochemical performance

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
  • Lithium iron phosphate anode material for lithium ion battery and modification method
  • Lithium iron phosphate anode material for lithium ion battery and modification method
  • Lithium iron phosphate anode material for lithium ion battery and modification method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0037] 1. Preparation of lithium iron phosphate precursor

[0038] 34.506g NH 4 h 2 PO 4 (0.3mol) into a 1L autoclave, add 250ml of distilled water to form 1.2mol / L NH 4 h 2 PO 4 solution, then 83.406gFeSO 4 ·7H 2 O (0.3mol) add NH 4 h 2 PO 4 Form uniform milky white suspension in the solution, then 187.5ml LiOH solution (c LiOH =4mol / L) was added in the suspension, gray-green precipitate appeared, stirred vigorously, and after the reaction was complete, 62.5ml Vc solution was added (c Vc =0.32mol / L). Sealed reaction at 210°C and autogenous pressure of 0.8MPa for 12-60 hours, after cooling, the product was washed, filtered, and dried at 60°C to obtain a lithium iron phosphate precursor. X-ray diffraction pattern as figure 1 , indicating that the product is LiFePO 4 , TEM photo as figure 2 , it can be seen that the crystal particles are flakes with a length of about 500 nm.

[0039] 2. Preparation of modified lithium iron phosphate cathode material

[0040] We...

Embodiment 2

[0046] 34.506g NH 4 h 2 PO 4 (0.3mol) into a 1L autoclave, add 250ml of distilled water to form 1.2mol / L NH 4 h 2 PO 4 solution, then 83.406g FeSO 4 ·7H 2 O (0.3mol) add NH 4 h 2 PO 4Form uniform milky white suspension in the solution, then 225ml LiOH solution (c LiOH =4mol / L) was added into the suspension, gray-green precipitate appeared, vigorously stirred, and 25ml Vc solution was added after the reaction was complete (c Vc = 1.2 mol / L). Sealed reaction at 210°C and autogenous pressure of 0.8MPa for 12-60 hours, after cooling, the product was washed, filtered, and dried at 60°C to obtain a lithium iron phosphate precursor.

[0047] Weigh 10g of lithium iron phosphate precursor, 0.3g of acetylene black, 0.135g of Mg(CH 3 COO) 2 After uniform mixing, absolute ethanol was used as a ball milling medium, and the mixture was dried at 80° C. after ball milling for 4-8 hours. Finally, it was calcined at 650°C for 8h. A lithium iron phosphate cathode material coated w...

Embodiment 3

[0050] 41.407g NH 4 h 2 PO 4 (0.36mol) into a 1L autoclave, add 300ml of distilled water to form 1.2mol / L NH 4 h 2 PO 4 solution, and then 100.087g FeSO 4 ·7H 2 O (0.36mol) add NH 4 h 2 PO 4 A uniform milky white suspension was formed in the solution, and then 225ml of 4mol / L LiOH solution (LiOH was 0.9mol) was added to the suspension, a gray-green precipitate appeared, stirred vigorously, and 75ml of Vc solution was added after the reaction was complete (c Vc =0.32mol / L). Sealed reaction at 210°C and autogenous pressure of 0.8MPa for 12-60 hours, after cooling, the product was washed, filtered, and dried at 60°C to obtain a lithium iron phosphate precursor.

[0051] Weigh 10 g of lithium ferrous phosphate, 1.5 g of glucose, 0.14 g of Zn(CH 3 COO) 2 Add 10 mL of distilled water and stir for 10 minutes. Drying at 105°C gave the mixture. The mixture was calcined at 600° C. for 8 hours in nitrogen to obtain a lithium iron phosphate cathode material coated with a con...

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
Login to view more

Abstract

The invention provides a lithium iron phosphate anode material used for lithium ion batteries; the lithium iron phosphate which is prepared by a water heating method is taken as a precursor which is then uniformly mixed with a conductive matter precursor and metal ion salt, and finally baked in inert gas to obtain the lithium iron phosphate anode material which is coated by the conductive matter and doped by the metal ions. Compared with a pure solid phase reaction method, the method of the invention has small energy dissipation, the chemical uniformity of the synchronized outcome is good, the dimension and the appearance of the outcome are uniform, and the electromechanical performance and the processing performance have good stability and repeatability. Compared with the a pure water heating method, as the coating of the conductive matter, the doping and modifying performance of the metal ions are added during the anaphase, the electric conductivity of the material is greatly improved, and the high magnification electromechanical performance of the material is excellent; wherein, under the 10C discharging magnification, the discharging content of the lithium iron phosphate anode material with the copper ion doped is kept at 107mAh / g. After circulation for 50 times, the discharging content of the material is kept unchangeable basically, which can certify that the material has good circulation performance.

Description

1. Technical field [0001] The invention belongs to the technical field of preparation of electrochemical power source materials, and relates to a modified lithium iron phosphate cathode material for lithium ion batteries and a modification method thereof. 2. Background technology [0002] The 20th century was a gasoline-powered society. However, the limited reserves of oil and the pollution caused by automobiles are problems to be solved in the 21st century and have attracted widespread attention. Actively developing alternative energy can fundamentally solve the above problems. Therefore, the development of power batteries is a key measure to solve this problem. At present, there are four types of secondary batteries commonly used: lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries and lithium-ion batteries. Although lead-acid batteries are cheap, they have small specific capacity, a short charging trip, fewer charge and discharge times, short s...

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): H01M4/58H01M4/48H01M4/04C01B25/45B01J19/00
CPCY02E60/10
Inventor 张卫新杨则恒王强王华
Owner HEFEI UNIV OF TECH
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