Search

CN-122025767-A - Nanoscale oxide solid electrolyte and preparation method and application thereof

CN122025767ACN 122025767 ACN122025767 ACN 122025767ACN-122025767-A

Abstract

The invention belongs to the technical field of battery materials, and provides a nanoscale oxide solid electrolyte, a preparation method and application thereof, wherein the preparation method is used for preparing nano inverse microemulsion by mixing high-steric-hindrance phosphate modified carbon quantum dots, oxide solid electrolyte raw materials and water-soluble polymers; then mixing the solution with a precipitator to carry out precipitation reaction, and then washing and calcining the precipitate to obtain the nano-scale oxide solid electrolyte with micropores. The prepared nanoscale oxide solid electrolyte has the characteristics of difficult agglomeration, good dispersibility and the like, and has high uniformity, high sphericity and rich micropores by using phosphate modified carbon quantum dots with high steric hindrance effect as an emulsifier. The preparation method is favorable for solving the problems of high energy consumption, long period, multiple synthesis procedures, large product granularity, low ion conductivity, high solid-solid interface impedance and the like of the main flow production route such as the traditional high-temperature solid phase method, the high-energy ball milling method and the like of the oxide solid electrolyte in the current market.

Inventors

  • Zhai Xiangang
  • YAN DONGWEI
  • ZHU WU
  • Lei Tidie
  • SONG SHIWEN

Assignees

  • 天津国安盟固利新材料科技股份有限公司

Dates

Publication Date
20260512
Application Date
20260410

Claims (10)

  1. 1. The preparation method of the nanoscale oxide solid electrolyte is characterized by comprising the following steps of: Providing a high sterically hindered phosphate modified carbon quantum dot, the carbon quantum dot having amphiphilicity, the high sterically hindered phosphate comprising at least one of sodium tripolyphosphate, sodium pyrophosphate, or sodium hexametaphosphate; Mixing an oxide solid electrolyte raw material comprising a lithium source, the high-steric hindrance phosphate modified carbon quantum dots and a water-soluble polymer to form an aqueous phase mixed solution; mixing the nano reverse microemulsion with a precipitator, and performing precipitation reaction to obtain a precipitate; and washing the obtained precipitate, and calcining to obtain the nano-scale oxide solid electrolyte with micropores.
  2. 2. The method for producing a nanoscale oxide solid state electrolyte according to claim 1, wherein the production method satisfies at least one of the following conditions: (A1) Mixing a carbon source with high-steric-hindrance phosphate, and performing microwave carbonization reaction to obtain the high-steric-hindrance phosphate modified carbon quantum dot; (A2) The carbon source comprises at least one of citric acid, ammonium citrate, glucose, sucrose and urea; (A3) After the carbon source is mixed with the high-steric-hindrance phosphate, the concentration of the carbon source is 0.25 g/mL-1 g/mL; (A4) The mass ratio of the high-steric-hindrance phosphate to the carbon source is 1 (5-20); (A5) The microwave power of the microwave carbonization reaction is 600-800W, and the time is 120-180 s; (A6) The particle size range of the high-steric-hindrance phosphate modified carbon quantum dot is 1 nm-5 nm.
  3. 3. The method for producing a nanoscale oxide solid state electrolyte according to claim 1, wherein the production method satisfies at least one of the following conditions: (B1) The oxide solid electrolyte includes at least one of a NASICON type including LATP, a garnet type including LLZO, or a perovskite type including LLTO; (B2) The lithium source comprises lithium nitrate and/or lithium hydroxide, and the total mass excess of the lithium source relative to other oxide solid electrolyte raw materials is 5% -10%; (B3) In the water phase mixed solution, the mass of the high-steric-hindrance phosphate modified carbon quantum dots accounts for 0.6% -4.8% of the mass of the oxide solid electrolyte which is theoretically generated; (B4) The water-soluble polymer comprises at least one of polymethacrylic acid, carboxymethyl cellulose, polyethylene glycol, polyvinyl alcohol or polyacrylamide; (B5) In the water phase mixed solution, the mass of the water-soluble polymer accounts for 1% -5% of the mass of the oxide solid electrolyte generated by theory; (B6) In the water phase mixed solution, the concentration of the water-soluble polymer is 1 g/L-10 g/L; (B7) The volume of the oily solvent is 1-5 times of the volume of the water phase mixed solution; (B8) The oily solvent comprises at least one of industrial oil, long carbon chain organic alcohols, esters, alkanes or aromatic hydrocarbons; (B9) The emulsification treatment is carried out under ultrasound, and the ultrasound time is 10-20 min; (B10) In the nano reverse microemulsion, the size range of micro liquid drops is 40 nm-200 nm.
  4. 4. The method for producing a nanoscale oxide solid state electrolyte according to claim 1, wherein the production method satisfies at least one of the following conditions: (C1) The precipitant comprises ammonia water and/or ammonium bicarbonate solution; (C2) The pH of the precipitation reaction is 7-9, the temperature is 30-60 ℃ and the time is 0.5-1 h; (C3) After the precipitation reaction is finished, performing centrifugal demulsification, washing to remove the oily solvent and the high-steric-hindrance phosphate modified carbon quantum dots to obtain the precipitate, and drying the precipitate at 80-120 ℃ for 12-24 hours to obtain dried powder; (C4) The calcination is carried out in an oxygen-containing atmosphere, the temperature is 400-600 ℃, and the time is 2-4 hours.
  5. 5. A nanoscale oxide solid state electrolyte, characterized in that it is obtainable by the preparation method according to any one of claims 1 to 4.
  6. 6. The nanoscale oxide solid state electrolyte of claim 5, wherein the nanoscale oxide solid state electrolyte has a median particle diameter Dv50 of 40nm to 100nm.
  7. 7. A method for producing a solid electrolyte membrane sheet, comprising the step of press-molding the nano-scale oxide solid electrolyte according to claim 5 or 6 to obtain a solid electrolyte membrane sheet.
  8. 8. The method according to claim 7, wherein the pressing is followed by secondary calcination, the secondary calcination is performed at 600 ℃ to 900 ℃ for 5h to 10h, and the solid electrolyte membrane is obtained.
  9. 9. A solid electrolyte membrane sheet, characterized by being obtained according to the manufacturing method of claim 7 or 8.
  10. 10. A battery comprising the oxide solid electrolyte according to claim 5 or 6, or the solid electrolyte membrane sheet according to claim 9.

Description

Nanoscale oxide solid electrolyte and preparation method and application thereof Technical Field The invention belongs to the technical field of battery materials, and relates to a nanoscale oxide solid electrolyte, a preparation method and application thereof. Background The oxide solid electrolyte has the advantages of high safety, strong chemical stability, high mechanical strength, wide electrochemical window and the like, is one of main stream electrolytes of solid batteries, and can be suitable for high-voltage anodes and lithium metal cathodes. Currently, the main mass production route of oxide solid electrolyte is a high-temperature solid phase method, namely, a solid raw material is subjected to chemical reaction by high-temperature heating to directly generate a target product. The method is mature in process, but the product has the problems of coarse particles (usually 1-5 mu m), wide particle size distribution, poor uniformity, high amorphous ratio, low room-temperature ion conductivity, high solid-solid interface impedance and the like. Therefore, multiple grinding, dispersing, drying or sintering processes are often required for improvement, which in turn complicates the preparation steps, greatly prolongs the synthesis period, and results in low production efficiency of the small-particle-size high-dispersion product. Disclosure of Invention In view of the problems existing in the prior art, the invention aims to provide a nanoscale oxide solid electrolyte, a preparation method and application thereof, wherein the preparation method can obtain the nanoscale oxide solid electrolyte which is super-dispersed, high in particle uniformity, high in sphericity and internally rich in micropores, can remarkably improve the ion conductivity of the oxide solid electrolyte, is beneficial to increasing the contact area between the oxide solid electrolyte and an electrode material, and is beneficial to reducing the solid-solid interface impedance between the oxide solid electrolyte and the electrode material. To achieve the purpose, the invention adopts the following technical scheme: In a first aspect, the present invention provides a method for preparing a nanoscale oxide solid electrolyte, comprising the steps of: Providing a high sterically hindered phosphate modified carbon quantum dot, the carbon quantum dot having amphiphilicity, the high sterically hindered phosphate comprising at least one of sodium tripolyphosphate, sodium pyrophosphate, or sodium hexametaphosphate; Mixing an oxide solid electrolyte raw material comprising a lithium source, the high-steric hindrance phosphate modified carbon quantum dots and a water-soluble polymer to form an aqueous phase mixed solution; mixing the nano reverse microemulsion with a precipitator, and performing precipitation reaction to obtain a precipitate; and washing the obtained precipitate, and calcining to obtain the nano-scale oxide solid electrolyte with micropores. The nanocrystallization means is beneficial to improving the ion conductivity of the oxide solid electrolyte and increasing the contact area with electrode materials (including active materials), thereby reducing the solid-solid interface impedance between the oxide solid electrolyte and the electrode materials such as high-voltage positive electrode materials. However, the existing nanocrystallization scheme, such as the traditional ball milling method, cannot meet the requirements of consistency and sphericity of particles, has limited improvement on solid-solid interface impedance, and has long time consumption, high energy consumption and large material consumption, while the chelating agent used in the sol-gel method has high cost, low yield of the hydrothermal synthesis method and high requirements on equipment, and is difficult to be suitable for large-scale production. In the preparation method of the nanoscale oxide solid electrolyte, high-steric-hindrance phosphate modified carbon quantum dots are adopted to participate in synthesis, wherein the high-steric-hindrance phosphate refers to anions in the phosphate with a larger steric hindrance effect in a three-dimensional space, and the modified carbon quantum dots refer to carbon quantum dots loaded, adsorbed or combined with anions of the phosphate and/or the phosphate so as to utilize the steric hindrance effect generated by the phosphate and/or the anions of the phosphate. The high-steric-hindrance phosphate-modified carbon quantum dot has amphiphilicity and high particle stability, can be used as an emulsifier to form stable nano reverse microemulsion together with an oxide solid electrolyte raw material and a water-soluble polymer, wherein the water-soluble polymer and the oxide solid electrolyte raw material are dissolved in micro-droplets of a water phase, the micro-droplets are wrapped by the water-soluble polymer and oil-water interface due to the existence of the high-steric-hindrance phosphate-modified carbon quantum dot,