Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Method for producing lithium iron phosphate

A lithium iron phosphate, precursor technology, applied in chemical instruments and methods, phosphorus compounds, inorganic chemistry, etc., can solve the problems of adhesion to precursors, affecting product quality, low tap density, etc., to achieve easy scale The effect of chemical production, lower production cost and good compactness

Active Publication Date: 2009-12-09
YUNNAN NENGTOU HUILONG TECH
View PDF3 Cites 3 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In this invention, as the temperature rises, the material as the precursor will react and release gas, and the invention is covered with a corundum sheet, which is carried out in a relatively airtight container, and there is no channel for the gas to be discharged smoothly , there are the following deficiencies: 1. the gas expands and the pressure rises, causing safety problems; 2. when the invention uses ammonium hydrogen phosphate and ammonium dihydrogen phosphate, the ammonia, water and carbon dioxide produced in the sintering process are in the process of cooling the reaction material boat Ammonium bicarbonate crystal particles will be produced and cause product pollution; ③The precursor body will melt during the roasting process, and the carbon powder will be directly covered on the precursor body, which will cause the carbon powder to stick to the precursor body during sintering, affecting the quality of the final product. quality, and the sinking of the melted precursor causes a space on the top of the reaction boat, and the gas generated by the reaction exists in this space to pollute the finished product; ④The synthesized lithium ferrous phosphate is loose and porous, so the tap density is low, and the general gram capacity is less than 120mMh / g

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
  • Method for producing lithium iron phosphate
  • Method for producing lithium iron phosphate
  • Method for producing lithium iron phosphate

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0036] Such as figure 1 As shown, lithium hydroxide: ferrous oxalate: ammonium dihydrogen phosphate was mixed in a molar ratio of 1.1:1:1, and 5% carbon black was added by mass ratio, and placed in a stirring ball mill for mixing and grinding for 5 hours; The precursor prepared by mixing and grinding is put into a stainless steel box, the precursor powder is compacted with a hydraulic press, and the high temperature resistant plate that is higher than the box is pressed on the precursor material, leaving a gap between the high temperature resistant plate and the box, and then Put the stainless steel box and the high temperature plate upside down into a semi-closed container, add carbon powder to fill up the semi-closed box, and finally spread the high temperature plate with fine holes on the carbon powder; then put it in a vacuum The box was evacuated for 0.5 hours and then filled with high-purity nitrogen. Finally, the precursor was sent to a tunnel kiln for calcination. It w...

Embodiment 2

[0038] Lithium carbonate: ferrous oxalate: ammonium dihydrogen phosphate: Mg(OH) 2 Mix at a molar ratio of 0.5:0.95:1:0.05, add 8% glucose by mass ratio, place in a stirring ball mill for mixing and grinding for 5 hours; put the precursor prepared by fully mixing and grinding into a stainless steel box, and use a hydraulic press Compact the precursor powder, press the high temperature resistant plate above the box body on the precursor material, so that there is a gap of 5 wires between the high temperature resistant plate and the box body, and then turn the stainless steel box body together with the high temperature resistant plate upside down. Put it into a semi-closed container, add charcoal powder to fill up the semi-closed box, and finally spread the high-temperature plate on the charcoal powder, so that there is a gap of 5 wires between the high-temperature plate and the box; then place it in a vacuum The box was evacuated for 0.5 hours and then filled with high-purity n...

Embodiment 3

[0040] Lithium carbonate and iron phosphate were mixed in a molar ratio of 0.5:1, and 10% glucose was added in a mass ratio, and placed in a stirring ball mill for mixing and grinding for 5 hours; the precursor prepared by fully mixing and grinding was loaded into a stainless steel box, Use a hydraulic press to compact the precursor powder, and press the high temperature resistant plate out of the box body on the precursor material, leaving a gap between the high temperature resistant plate and the box body, and then put the stainless steel box body together with the high temperature resistant plate upside down into a In the semi-closed container, add charcoal powder to fill the semi-closed box around, and finally spread the high-temperature resistant plate with fine holes on the charcoal powder; finally send the precursor into the tunnel kiln for roasting, and start heating from room temperature , the heating rate is 10°C / min, heated to 700°C and roasted for 6 hours, then cool...

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

No PUM Login to View More

Abstract

The invention discloses a method for producing lithium iron phosphate without inert atmosphere protection, aiming at realizing the aim of reducing the manufacturing cost of positive material of a lithium iron phosphate battery. The method comprises the steps: the prepared precursor material is put into a semi-enclosed box body and pressed to be compact to exhaust the air in the precursor material; a high temperature resistant plate which is higher than the box body is arranged, and a gap is left between the high temperature resistant plate and the box body; then, the semi-enclosed box body and the high temperature resistant plate are arranged inside another semi-enclosed box body in a inverted way, and a carbon dust layer is filled into the box body; the high temperature resistant plate provided with the slim holes is laid on carbon dust or the gap is left between the high temperature resistant plate and the box body; the obtained semi-enclosed box body that is provided with the precursor and the carbon dust is firstly vacuumized and then filled with non-oxidizing gas for replacing the air in the precursor and the carbon dust; the box body is placed into a calcination device and heated from the room temperature to be 600-800 DEG C at the speed of 5-20 DEG C / min; after that, the temperature is maintained for 6-24h for calcination, and then the product is cooled to be the room temperature along with a furnace.

Description

technical field [0001] The invention relates to a positive electrode material of a lithium battery, and more particularly to a preparation method of lithium iron phosphate, a positive electrode material of a lithium ion battery. Background technique [0002] Lithium ferrous phosphate is a new electrode material for lithium-ion batteries. Its characteristics are: ① High energy density, the theoretical specific capacity is 170mAh / g, and the actual specific capacity of the product can exceed 140mAh / g (0.2C, 25℃); ② , safe, is currently the safest lithium-ion battery cathode material, does not contain any heavy metal elements harmful to the human body; ③, long life, under 100% DOD conditions, can charge and discharge more than 2000 times; no memory effect; ④, charging Performance, lithium iron phosphate lithium battery as the positive electrode material can be charged at a high rate to achieve fast charging. Although lithium iron phosphate battery has high safety and long life ...

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
IPC IPC(8): C01B25/45
Inventor 杨成云
Owner YUNNAN NENGTOU HUILONG TECH
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com