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CN-121988274-A - Fluorine doped ion sieve precursor, preparation method and application thereof

CN121988274ACN 121988274 ACN121988274 ACN 121988274ACN-121988274-A

Abstract

The invention discloses a fluorine doped ion sieve precursor, wherein the fluorine content of the fluorine doped ion sieve precursor is 0.2% -2%, and the particle size is 80-150nm. The invention also discloses a preparation method of the fluorine-doped ion sieve precursor, which comprises the steps of preparing a metal salt solution A of manganese and lithium, preparing a citric acid solution B and a fluorine-containing salt solution D, mixing the solution A and the solution B, heating and stirring to obtain a colloidal solution C, vacuum drying the solution C to obtain a solid intermediate, grinding the solid intermediate, calcining in a muffle furnace to obtain the ion sieve precursor, marking the ion sieve precursor as LMO powder, weighing the LMO powder, placing the LMO powder in a reaction kettle, adding the fluorine-containing salt solution D and deionized water, placing the reaction kettle in the muffle furnace for heat treatment to obtain precursor slurry, and performing suction filtration, washing and drying on the precursor slurry to obtain the fluorine-doped ion sieve precursor. According to the invention, through fluorine doped ion sieve precursors, a disproportionation reaction electron transmission path is changed, and the problem of manganese dissolution loss phenomenon of LiMn 2 O 4 in the process of adsorbing and extracting lithium is solved.

Inventors

  • XU HUI
  • JIANG LONG
  • ZHANG XIANG
  • BAI XIAOLIANG
  • CAI KE

Assignees

  • 中国石油天然气集团有限公司
  • 中国石油集团工程材料研究院有限公司

Dates

Publication Date
20260508
Application Date
20241104

Claims (10)

  1. 1. The fluorine doped ion sieve precursor is characterized in that the fluorine content of the fluorine doped ion sieve precursor is 0.2% -2%, and the particle size is 80-150nm.
  2. 2. The preparation method of the fluorine doped ion sieve precursor is characterized by comprising the following steps of: step 1, preparing a metal salt solution A containing manganese and lithium ions, and preparing a citric acid solution B and a fluorine-containing salt solution D; Step 2, mixing the solution A and the solution B, heating and stirring to obtain a colloidal solution C; step 3, carrying out vacuum drying on the solution C to obtain a solid intermediate; step 4, grinding the solid intermediate, and then placing the solid intermediate in a muffle furnace for calcination to obtain an ion sieve precursor which is marked as LMO powder; step 5, weighing LMO powder, placing the LMO powder in a reaction kettle, adding fluorine-containing salt solution D and deionized water, stirring and performing ultrasonic treatment; step 6, placing the reaction kettle in a muffle furnace for heat treatment to obtain precursor slurry; And 7, carrying out suction filtration, washing, drying and sieving on the precursor slurry to obtain a fluorine doped ion sieve precursor, which is marked as F-LMO.
  3. 3. The method for preparing a fluorine-doped ion sieve precursor according to claim 2, wherein the manganese metal salt in the solution A is one or two of manganese acetate tetrahydrate and manganese nitrate, and the lithium metal salt is lithium nitrate.
  4. 4. The method for preparing fluorine-doped ion sieve precursor according to claim 3, wherein the molar ratio of lithium ions to manganese ions in the solution A is 1 (1-4).
  5. 5. The method for preparing fluorine-doped ion sieve precursor according to claim 3, wherein the solution A and the solution B are mixed, and the molar ratio of citric acid to nitrate in the mixed system is 1 (1-4).
  6. 6. The method for preparing a fluorine-doped ion sieve precursor according to claim 2, wherein the fluorine-containing salt in the solution D is one or more of 1-butyl-3-methylimidazolium tetrafluoroborate, 1-butyl-3-methylimidazolium hexafluorophosphate and 1-ethyl-3-methylimidazolium bistrifluoromethane sulfonyl imide salt.
  7. 7. The method for preparing a fluorine-doped ion sieve precursor according to claim 2, wherein the calcining condition is that the furnace temperature is raised from room temperature to 350-420 ℃ and kept for 4-10h, and the furnace temperature is continuously raised from 350-420 ℃ to 450-500 ℃ and kept for 1-6h.
  8. 8. The method for preparing a fluorine-doped ion sieve precursor according to claim 2, wherein the heat treatment condition is specifically a reaction temperature of 40-150 ℃ and a reaction time of 0.5-3h.
  9. 9. The method of preparing a fluorine doped ion screen precursor according to claim 2, wherein the molar ratio of LMO powder to solution D is 1 (1-2).
  10. 10. Use of a fluorine-doped ion sieve precursor according to claim 1 or prepared by a preparation method according to any one of claims 2 to 9 for preparing a fluorine-doped lithium ion sieve.

Description

Fluorine doped ion sieve precursor, preparation method and application thereof Technical Field The invention belongs to the technical field of battery materials, relates to a fluorine-doped ion sieve precursor, and further relates to a preparation method and application of the fluorine-doped ion sieve precursor. Background Liquid lithium is a main form of lithium resources in China, and is mainly located in salt lakes, oil-gas fields, geothermal brine and the like in northwest regions of China. Brine extraction of lithium is of great significance in relieving the lithium resource market supply relationship and promoting energy form transformation. At present, the main forms of extracting lithium from brine include a salt pan precipitation method, a solution extraction method, electrodialysis, an adsorption method, a membrane method, an electrochemical method, a calcination method and the like. The inorganic adsorbent in the adsorption method is considered as one of the materials with the most application prospect, and the manganese-based lithium ion sieve is the current research focus due to the excellent lithium extraction effect, liMn 2O4 is one of representative precursors of the manganese-based lithium ion sieve, and the HMn 2O4 ion sieve is obtained through acidification, so that the HMn 2O4 ion sieve has better lithium extraction amount and selectivity compared with other ion sieves. LiMn 2O4 is mainly used for lithium battery electrodes and has good Li + transmission efficiency, but the substance contains Mn 3+ and Mn 4+, wherein Mn 3+ is easy to perform disproportionation reaction under acidic conditions to generate Mn 2+ and Mn 4+, so that manganese dissolution loss, namely Mn 2+, is dissolved in a solution, and the severity of the manganese dissolution loss is higher than that of Li 1.6Mn1.6O4. Therefore, it is necessary to solve the phenomenon of manganese dissolution loss of LiMn 2O4 in the adsorption and lithium extraction process. Disclosure of Invention The first object of the invention is to provide a fluorine doped ion sieve precursor, which solves the problem of manganese dissolution loss phenomenon of LiMn 2O4 in the adsorption and lithium extraction process in the prior art. The second object of the invention is to provide a preparation method of fluorine-doped ion sieve precursors, wherein the fluorine-doped lithium ion sieve precursors are used for synthesizing fluorine-doped lithium ion sieves. The first technical scheme adopted by the invention is that fluorine content of the fluorine doped ion sieve precursor is 0.2% -2%, and particle size is 80-150nm. The second technical scheme adopted by the invention is that the preparation method of the fluorine doped ion sieve precursor comprises the following steps: step 1, preparing a metal salt solution A containing manganese and lithium ions, and preparing a citric acid solution B and a fluorine-containing salt solution D; step 2, mixing the solution A and the solution B, heating and stirring to obtain a colloidal solution C; step 3, carrying out vacuum drying on the solution C to obtain a solid intermediate; Step 4, grinding the solid intermediate, and then placing the solid intermediate in a muffle furnace for calcination to obtain an ion sieve precursor, which is marked as LMO powder; step 5, weighing LMO powder, placing the LMO powder in a reaction kettle, adding fluorine-containing salt solution D and deionized water, stirring and performing ultrasonic treatment; step 6, placing the reaction kettle in a muffle furnace for heat treatment to obtain precursor slurry; And 7, carrying out suction filtration, washing, drying and sieving on the precursor slurry to obtain a fluorine doped ion sieve precursor, which is marked as F-LMO. The second technical scheme of the invention is characterized in that: The manganese metal salt in the solution A is one or two of tetrahydrate manganese acetate and manganese nitrate, and the lithium metal salt is lithium nitrate. The molar ratio of lithium and manganese ions in the solution A is 1 (1-4). The solution A and the solution B are mixed, and the molar ratio of citric acid to nitrate in the mixed system is 1 (1-4). The fluorine-containing salt in the solution D is one or more of 1-butyl-3-methylimidazole tetrafluoroborate, 1-butyl-3-methylimidazole hexafluorophosphate and 1-ethyl-3-methylimidazole bis (trifluoromethanesulfonyl) imide salt. The calcining condition is that the furnace temperature is raised from room temperature to 350-420 ℃, and the temperature is kept for 4-10h, and the furnace temperature is continuously raised from 350-420 ℃ to 450-500 ℃ and the temperature is kept for 1-6h. The heat treatment condition is specifically that the reaction temperature is 40-150 ℃ and the reaction time is 0.5-3h. The molar ratio of LMO powder to solution D was 1 (1-2). Application of fluorine doped ion sieve precursor in preparing fluorine doped lithium ion sieve. The beneficial effects of the invention