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CN-121983651-A - Preparation method of doped modified lithium titanium aluminum phosphorus solid electrolyte

CN121983651ACN 121983651 ACN121983651 ACN 121983651ACN-121983651-A

Abstract

The invention relates to a preparation method of a doped modified lithium titanium aluminum phosphorus solid electrolyte, and belongs to the technical field of solid electrolyte materials. Adding lithium carbonate, titanium dioxide, aluminum dihydrogen phosphate, zinc oxide, a modified zinc ion stabilizer and absolute ethyl alcohol into a ball milling tank for ball milling, drying, sieving and granulating to obtain a granular material; placing the granular materials in a muffle furnace, sintering at high temperature, grinding, and sieving to obtain the doped modified lithium titanium aluminum phosphorus solid electrolyte; the modified zinc ion stabilizer is prepared from 2- [ (thiophene-2-ylmethoxy) methyl ] ethylene oxide, DMF, octa (aminophenyltrialkoxysilane), potassium ethoxide, zinc maleate and dibutyl tin dilaurate, and the solid electrolyte prepared by the method has the advantages of remarkably improved ion conductivity at room temperature and excellent cycle performance, and is suitable for high-energy-density solid lithium ion batteries.

Inventors

  • HUANG BIYING
  • LI HONGKE
  • HUANG YAOMING
  • ZHOU JING
  • ZHANG YIN

Assignees

  • 联合能源控股集团有限公司

Dates

Publication Date
20260505
Application Date
20260129

Claims (8)

  1. 1. The preparation method of the doped modified lithium titanium aluminum phosphorus solid electrolyte comprises the following operation steps of: S1, mixing raw materials, namely adding 50-58 parts of lithium carbonate, 23-35 parts of titanium dioxide, 12-19 parts of aluminum dihydrogen phosphate, 0.5-2.5 parts of zinc oxide and 0.1-0.5 part of modified zinc ion stabilizer into a ball milling tank, adding 80-120 parts of absolute ethyl alcohol as a dispersing agent, and performing ball milling to obtain mixed slurry; S2, drying and granulating, namely vacuum drying the mixed slurry, removing absolute ethyl alcohol to obtain dry powder, and sieving the dry powder with a 80-120-mesh sieve to granulate to obtain a granular material; s3, sintering at high temperature, namely placing the granular materials into a muffle furnace, and sintering at high temperature in an argon atmosphere; s4, grinding, namely putting the sintered blocks after high-temperature sintering into a planetary ball mill, adding agate grinding balls, grinding under the protection of argon, and sieving with a 200-300-mesh sieve to obtain the doped modified lithium titanium aluminum phosphorus solid electrolyte; The modified zinc ion stabilizer is prepared by reacting 2- [ (thiophene-2-ylmethoxy) methyl ] ethylene oxide, eight (aminophenyl trioxysilane), potassium ethoxide, zinc maleate and dibutyl tin dilaurate.
  2. 2. The preparation method of the doped and modified lithium titanium aluminum phosphorus solid electrolyte according to claim 1, wherein the ball milling tank and the grinding balls of the S1 are made of agate, and the ball-material ratio is 10-15:1.
  3. 3. The preparation method of the doped and modified lithium titanium aluminum phosphorus solid electrolyte according to claim 1, wherein the rotation speed of the S1 ball milling is 300-500r/min, and the ball milling time is 6-10h.
  4. 4. The method for preparing the doped and modified lithium titanium aluminum phosphorus solid electrolyte according to claim 1, wherein the S2 is dried in vacuum at 60-80 ℃ for 8-12 hours.
  5. 5. The preparation method of the doped and modified lithium titanium aluminum phosphorus solid electrolyte according to claim 1 is characterized in that the S3 high-temperature sintering step is that the temperature is firstly increased to 400-500 ℃ at the temperature increasing rate of 5-8 ℃ per minute, the temperature is kept for 2-3 hours, the temperature is then increased to 850-950 ℃ at the temperature increasing rate of 3-5 ℃ per minute, and the temperature is kept for 6-10 hours.
  6. 6. The preparation method of the doped and modified lithium titanium aluminum phosphorus solid electrolyte according to claim 1, wherein the grinding speed of S4 is 200-300r/min, and the grinding time is 2-4h.
  7. 7. The method for preparing the doped modified lithium titanium aluminum phosphorus solid electrolyte according to claim 1, wherein the method for preparing the modified zinc ion stabilizer is as follows: A1, adding 17-34 parts of 2- [ (thiophen-2-ylmethoxy) methyl ] ethylene oxide, 350-480 parts of DMF, 11-23 parts of octa (aminophenyl trioxysilane) and 5-8 parts of potassium ethoxide into a reaction kettle according to parts by weight, stirring and heating to 50-60 ℃ under the atmosphere of nitrogen, and reacting for 2-5 hours; A2, adding 3-6 parts of zinc maleate and 0.5-0.8 part of dibutyl tin dilaurate, heating to 75-85 ℃, reacting for 3-8 hours, cooling to room temperature after the reaction is finished, adding 200-250 parts of deionized water into the reaction solution, precipitating solid, filtering, collecting, recrystallizing with absolute ethyl alcohol for 2-3 times, and drying in vacuum to obtain the modified zinc ion stabilizer.
  8. 8. The method for preparing the doped modified lithium titanium aluminum phosphorus solid electrolyte according to claim 7, wherein the vacuum drying temperature is 55-65 ℃ and the time is 7-9h.

Description

Preparation method of doped modified lithium titanium aluminum phosphorus solid electrolyte Technical Field The invention relates to the technical field of solid electrolyte materials, in particular to a preparation method of a doped modified lithium titanium aluminum phosphorus solid electrolyte. Background With the wide application of lithium ion batteries in the fields of electric automobiles, energy storage systems, portable electronic equipment and the like, potential safety hazards such as liquid leakage, flammability, explosiveness and the like of the traditional liquid electrolyte lithium ion battery are increasingly prominent, and the further development of the lithium ion battery in the fields of high energy density and high safety is severely limited. The solid electrolyte is used as a core component of the solid lithium ion battery, has the advantages of no liquid leakage, incombustibility, good thermal stability and the like, can fundamentally solve the safety problem caused by the liquid electrolyte, and becomes a research hot spot in the current lithium ion battery field. The lithium titanium aluminum phosphorus system solid electrolyte is considered to be one of the most potential solid electrolytes because of higher ionic conductivity and good chemical stability. Chinese patent CN120527441A, which belongs to the field of battery materials, discloses a modified PEO-based composite solid electrolyte, a preparation method and application thereof. The modified PEO-based composite solid electrolyte comprises a modified microporous metal oxide, PEO and lithium salt, wherein the modified microporous metal oxide comprises a core, an intermediate layer and a coating layer, the intermediate layer is at least coated on part of the surface of the core, and the coating layer is at least coated on part of the surface of solid particles formed by the core and the intermediate layer. Chinese patent CN120565789A discloses an iodine compound coated sulfide solid electrolyte, a preparation method and application thereof, and relates to the technical field of batteries. The preparation method comprises the steps of mixing and ball-milling the coating liquid and sulfide solid electrolyte powder to obtain a mixture, carrying out solid-liquid separation on the mixture to obtain a solid, washing the solid, drying, and carrying out heat treatment to obtain the sulfide solid electrolyte with the surface coated with the iodine compound. In the preparation process of the existing lithium titanium aluminum phosphorus solid electrolyte, the problems of crystal structure defects, unsmooth lithium ion transmission channel and the like are easy to occur, so that the room-temperature ionic conductivity is low, and the application requirements of a high-power solid lithium ion battery are difficult to meet. Meanwhile, the high-temperature sintering process is easy to cause electrolyte particle agglomeration and uneven grain growth, so that the ion transmission performance and electrochemical stability of the electrolyte are further reduced, and the large-scale industrialized application of the electrolyte is limited. Disclosure of Invention In order to solve the problems, the invention provides a preparation method of a doped modified lithium titanium aluminum phosphorus solid electrolyte, which comprises the following operation steps in parts by weight: S1, mixing raw materials, namely adding 50-58 parts of lithium carbonate, 23-35 parts of titanium dioxide, 12-19 parts of aluminum dihydrogen phosphate, 0.5-2.5 parts of zinc oxide and 0.1-0.5 part of modified zinc ion stabilizer into a ball milling tank, adding 80-120 parts of absolute ethyl alcohol as a dispersing agent, and performing ball milling to obtain mixed slurry; S2, drying and granulating, namely vacuum drying the mixed slurry, removing absolute ethyl alcohol to obtain dry powder, and sieving the dry powder with a 80-120-mesh sieve to granulate to obtain a granular material; s3, sintering at high temperature, namely placing the granular materials into a muffle furnace, and sintering at high temperature in an argon atmosphere; S4, grinding, namely putting the sintered blocks after high-temperature sintering into a planetary ball mill, adding agate grinding balls, grinding under the protection of argon, and sieving with a 200-300-mesh sieve to obtain the doped modified lithium titanium aluminum phosphorus solid electrolyte. The ball milling tank and the grinding balls of the S1 are made of agate, and the ball-material ratio is 10-15:1. The ball milling speed of the S1 is 300-500r/min, and the ball milling time is 6-10h. The vacuum drying temperature of the S2 is 60-80 ℃ and the time is 8-12h. The step of S3 high-temperature sintering is that the temperature is firstly increased to 400-500 ℃ at the temperature increasing rate of 5-8 ℃ per minute, the temperature is kept for 2-3h, and then the temperature is increased to 850-950 ℃ at the temperature increasing rate o