A kind of method for preparing ferrous phosphate-based lithium salt material in high-pressure liquid phase

A ferrous phosphate-based, high-pressure liquid-phase technology, applied in chemical instruments and methods, phosphorus compounds, inorganic chemistry, etc., can solve the problem of affecting the electrochemical performance of materials and electrodes, battery electrochemical performance, difficult to control crystallization uniformity, and complex preparation processes, etc. problem, to achieve the effect of improving electron mobility, reducing radius, and high purity

Inactive Publication Date: 2011-12-14
IRICO
View PDF6 Cites 2 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] In 1997, Goodenough et al. synthesized an olivine-type iron-containing lithium salt LiFePO 4 , the structure of the substance is stable, charging and discharging During the process, the volume change of the unit cell is small, and the cycle performance is excellent. Using this material as the positive electrode material of lithium-ion batteries has a high theoretical specific capacity (170mAh / g), which is greater than that of commercial LiCoO 2 The actual capacity performance of 140mAh / g has attracted great attention of researchers. At present, the preparation of this material is not very mature, there are many preparation methods, and the preparation process is still very complicated, especially some solid-phase methods, which are not easy to control. Its crystallization uniformity affects the electrode processing performance of the material and the electrochemical performance of the actual battery

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
  • A kind of method for preparing ferrous phosphate-based lithium salt material in high-pressure liquid phase
  • A kind of method for preparing ferrous phosphate-based lithium salt material in high-pressure liquid phase
  • A kind of method for preparing ferrous phosphate-based lithium salt material in high-pressure liquid phase

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0049] The lithium iron phosphate material is prepared by a high-pressure liquid phase method, and the preparation process is as follows:

[0050] 1) Under the reducing atmosphere of hydrogen, the mass percentage is 99.5% FeSO 4 ·7H 2 Adding 0.5% ascorbic acid in O to prepare iron salt solution, FeSO 4 ·7H 2 O solution and H 3 PO 4 According to the molar ratio of 1:1, the mixture is mixed in the liquid phase by stirring;

[0051] 2) LiOH·H 2 O and H in the above step 1) 3 PO 4 According to the molar ratio of 3:1, add it into the mixed solution and stir evenly, then add deionized water, and mix it into a white emulsion with a concentration of 3M;

[0052] 3) Transfer the homogeneously stirred emulsion in step 2) to a stainless steel hydrothermal reactor with polytetrafluoroethylene PTFE lining (the emulsion accounts for 50% of the volume of the reactor), and add the iron salt FeSO added in step 1). 4 ·7H 2 O mass percentage is 10% conductive agent carbon black, pass i...

Embodiment 2

[0057] The lithium iron phosphate material is prepared by a high-pressure liquid phase method, and the preparation process is as follows:

[0058] 1) LiOH·H 2 O solution and NH 4 h 2 PO 4 According to the molar ratio of 3:1, it is mixed in the liquid phase by stirring to form a mixed solution;

[0059] 2) Under a nitrogen reducing atmosphere, the mass percentage of 80% FeSO 4 ·7H 2 O solution was prepared by adding 20% ​​tartaric acid, and the dissolved FeSO 4 ·7H 2 O with step 1) NH 4 h 2 PO 4 According to the molar ratio of 1:1, add it into the uniformly mixed solution and stir evenly, then add deionized water, and mix to form a white emulsion with a concentration of 1M;

[0060] 3) Transfer the homogeneously stirred emulsion in step 2) to a stainless steel hydrothermal reactor with polytetrafluoroethylene PTFE lining (the emulsion accounts for 80% of the volume of the reactor), and add the iron salt FeSO added in step 2). 4 ·7H 2 O mass percentage is 1% conducti...

Embodiment 3

[0065] Preparation of doped lithium iron phosphate LiFe by high-pressure liquid phase method 1-x m x PO 4 , and its preparation process is as follows:

[0066] 1) Under a reducing atmosphere where nitrogen and hydrogen are mixed at a volume ratio of 9.5:0.5, according to FeSO 4 ·7H 2 O and MgSO 4 ·7H 2 O molar ratio is that the ratio of 99.9:0.1 is mixed with doped iron salt, is that 0.1% ascorbic acid is mixed with the ascorbic acid that adds mass percentage in 99.9% doping iron salt in mass percentage and is mixed with solution, FeSO 4 ·7H 2 O and MgSO 4 ·7H 2 O solution and H 3 PO 4 According to the molar ratio of 1:1, it is mixed into a solution in the liquid phase by stirring;

[0067] 2) LiOH·H 2 O follow with H 3 PO 4 Add the molar ratio of 3:1 to step 1) in the uniformly mixed solution and stir evenly, then add deionized water, and mix to form a 0.5M white emulsion;

[0068] 3) Transfer the homogeneously stirred emulsion in step 2) to a stainless steel h...

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 preparing a ferrous phosphate-based lithium salt material in a high-pressure liquid phase, comprising: firstly mixing the iron salt solution prepared with an organic reductive weak acid or deionized water and a phosphate-containing raw material, and then mixing the LiOH·H2O was added to the mixed solution and fully stirred with distilled water to form a white emulsion. Method B: first mix the phosphate-containing raw material with LiOH·H2O, then add the iron salt solution prepared with organic reducing weak acid or deionized water, and stir the mixed solution with distilled water to form a white emulsion. Add a conductive agent to the emulsion, adjust the pH value under a protective atmosphere, and seal the reaction; drop to room temperature, filter and precipitate to obtain a powder, and after vacuum baking, the powder is dried at a high temperature under a protective atmosphere to obtain a ferrous phosphate-based lithium salt material . The invention has simple preparation process and no pollution to the environment; the crystallization of the obtained substance is uniform and fine, and the product purity is high; the high-temperature reaction time is short, the temperature is low, the doping is simple and the cost is low, and it has good electrochemical performance.

Description

technical field [0001] The invention relates to the preparation of a lithium ion battery cathode active material, in particular to a preparation method of a lithium ion battery ferrous phosphate-based lithium salt material. Background technique [0002] Since the first lithium-ion battery came out in 1991, its cathode material has been a hot spot in material research. The development of cathode materials has experienced lithium cobaltate and its derivatives, lithium nickelate and its derivatives, lithium manganate and its derivatives, and so on. In recent years, due to the abundance of iron in the earth's crust, its cheap price, and environmental friendliness, based on Fe 2+ / Fe 3+ The substances of redox couples have aroused great interest, so people are racing to study iron-containing lithium salts and their derivatives to replace the current cathode materials. [0003] In 1997, Goodenough et al. synthesized an olivine-type iron-containing lithium salt LiFePO 4 , the 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): C01B25/45
Inventor 高洪森
Owner IRICO
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