CN-122000612-A - High heat-resistant conductive polymer coating diaphragm and preparation method and application thereof

Abstract

The invention relates to the technical field of battery diaphragms, and provides a high heat-resistant conductive polymer coating diaphragm, a preparation method and application thereof, wherein the high heat-resistant conductive polymer coating diaphragm comprises a base film and a coating coated on at least one side of the base film, the components of the coating comprise a polymer and a modifier, and the modifier comprises carboxylation LLZTO and PPTA. Through the technical scheme, the problems of insufficient high temperature resistance and lower ion conductivity of the polymer coating diaphragm in the related technology are solved.

Inventors

• XU FENG
• GAO JINGJING
• YUAN HAICHAO
• Su bihai
• WANG XIAOJING
• WU HUI
• HU XIAOKAI
• WANG RANRAN

Assignees

• 河北金力新能源科技有限公司

Dates

Publication Date

20260508

Application Date

20260113

Claims (10)

1. 1. The high heat-resistant conductive polymer coating diaphragm is characterized by comprising a base film and a coating coated on at least one side of the base film, wherein the coating comprises a polymer and a modifier, and the modifier comprises carboxylation LLZTO and PPTA.
2. 2. The high heat-resistant conductive polymer coating diaphragm according to claim 1, wherein the mass ratio of the polymer to the carboxylated LLZTO to the PPTA is 1-3:1-3:0.5-1; the polymer includes at least one of PEO, PAA, PAN, PMMA, PVDF-HFP.
3. 3. The high heat-resistant conductive polymer coating diaphragm according to claim 1, wherein the components of the coating further comprise lithium salt, and the mass ratio of the polymer to the lithium salt is 1-3:0.1-0.3.
4. 4. A highly heat resistant conductive polymer coated separator according to claim 3 wherein said lithium salt comprises at least one of lithium bis (trifluorosulfonimide), lithium hexafluorophosphate, lithium tetrafluoroborate.
5. 5. The high heat resistant conductive polymer coated separator according to claim 1, wherein carboxylated LLZTO is prepared by reacting LLZTO powder with polycarboxylic acid in the presence of a catalyst.
6. 6. The high heat-resistant conductive polymer coating diaphragm according to claim 1, wherein the particle size of LLZTO is 400-800 nm.
7. 7. The high heat-resistant conductive polymer coating diaphragm according to claim 1, wherein the PPTA is prepared by polycondensation reaction of p-phenylene diamine and terephthaloyl chloride.
8. 8. The high heat resistant conductive polymer coated separator according to claim 7, wherein the preparation method of PPTA comprises the following steps: under the protection of nitrogen, dissolving a cosolvent in an organic solvent, adding p-phenylenediamine, mixing, adding terephthaloyl chloride, reacting, adding imidazole, reacting, and filtering to obtain PPTA.
9. 9. A method for preparing the high heat-resistant conductive polymer coating diaphragm, which is used for preparing the high heat-resistant conductive polymer coating diaphragm according to any one of claims 1 to 8, and is characterized by comprising the following steps: stirring the components of the coating for 2-4 hours at the temperature of 40-60 ℃ and the speed of 300-500 r/min to obtain mixed slurry; and coating the mixed slurry on at least one side of the base film, and drying at 70-80 ℃ for 5-10 min to obtain the high heat-resistant conductive polymer coating diaphragm.
10. 10. The use of a highly heat-resistant conductive polymer coated separator according to any one of claims 1 to 8 or a highly heat-resistant conductive polymer coated separator manufactured by the manufacturing method of claim 9 in a solid state battery.

Description

High heat-resistant conductive polymer coating diaphragm and preparation method and application thereof Technical Field The invention relates to the technical field of battery diaphragms, in particular to a high heat-resistant conductive polymer coating diaphragm and a preparation method and application thereof. Background PEO composite LLZTO (polyethylene oxide composite lithium lanthanum zirconium titanium oxide) electrolyte membrane is the hot spot direction of current solid-state battery research, and the battery performance is remarkably improved by combining the flexibility of the polymer and the high ionic conductivity of LLZTO. By polymer-ceramic interfacial targeting effect, LLZTO agglomeration and polymer crystallization are inhibited, forming a uniform film structure of high mechanical strength. But currently there are several key issues faced: 1. LLZTO the filler is easy to agglomerate, LLZTO particles are easy to phase separate from the PEO matrix, so that an ion transmission path is discontinuous, 2 the PEO matrix has low ion conductivity (about 10 -8~10-6S·cm- 1) at room temperature and is not high-temperature resistant and only acts below 80 ℃,3 the flexibility of the PEO matrix is determined, the growth of lithium dendrites is difficult to inhibit, the mechanical strength is insufficient, 4 the PEO matrix is easy to oxidize and decompose under the voltage of about 4V, and the high-voltage application is limited. Thus, there is a need for a high temperature resistant conductive polymer coated separator. Disclosure of Invention The invention provides a high heat-resistant conductive polymer coating diaphragm, a preparation method and application thereof, and solves the problems of insufficient high temperature resistance and lower ionic conductivity of the polymer coating diaphragm in the related technology. The technical scheme of the invention is as follows: the invention provides a high heat-resistant conductive polymer coating diaphragm which comprises a base film and a coating coated on at least one side of the base film, wherein the coating comprises a polymer and a modifier, and the modifier comprises carboxylation LLZTO and PPTA. As a further technical scheme, the mass ratio of the polymer to the carboxylated LLZTO to the PPTA is 1-3:1-3:0.5-1; the polymer includes at least one of PEO, PAA, PAN, PMMA, PVDF-HFP. As a further technical scheme, the coating further comprises lithium salt, wherein the mass ratio of the polymer to the lithium salt is 1-3:0.1-0.3. As a further technical scheme, the lithium salt comprises at least one of lithium bis (trifluorosulfonimide), lithium hexafluorophosphate and lithium tetrafluoroborate. As a further technical scheme, the carboxylation LLZTO is prepared by reacting LLZTO powder with polycarboxylic acid under the action of a catalyst. As a further embodiment, the polycarboxylic acid comprises oxalic acid. In the invention, LLZTO is modified, polar group carboxyl is introduced through oxalic acid to induce a PEO amorphous region, thereby providing an ion transmission path and optimizing interface stability. The carboxyl group and PEO ether oxygen atom form a hydrogen bond network to strengthen the bonding force of the filler-matrix interface, and the PPTA rigid skeleton is introduced to form an interpenetrating network structure with PEO, so that the coating maintains mechanical integrity at high temperature and lithium dendrite penetration is avoided. As a further technical scheme, the catalyst comprises a quaternary ammonium salt catalyst, wherein the quaternary ammonium salt catalyst comprises tetrabutylammonium bromide. As a further technical scheme, the preparation method of carboxylation LLZTO comprises the following steps: As a further technical scheme, LLZTO powder is mixed with polycarboxylic acid, catalyst is added, reaction, centrifugation, washing and drying are carried out, and carboxylation LLZTO powder is obtained. As a further technical scheme, the mass ratio of LLZTO powder to polycarboxylic acid is 1-2:2-4. As a further technical scheme, the temperature during the reaction is 60-80 ℃, the time is 30-60 min, and the stirring speed is 300-500 r/min. As a further technical scheme, the grain size of LLZTO powder is 400-800 nm. As a further technical scheme, the PPTA is prepared by polycondensation reaction of p-phenylenediamine and terephthaloyl chloride serving as raw materials. As a further technical scheme, the preparation method of the PPTA comprises the following steps: under the protection of nitrogen, dissolving a cosolvent in an organic solvent, adding p-phenylenediamine, mixing, adding terephthaloyl chloride, reacting, adding imidazole, reacting, and filtering to obtain PPTA. As a further technical scheme, the cosolvent comprises a chloride of alkaline earth metal, and the chloride of alkaline earth metal comprises anhydrous lithium chloride. The invention also provides a preparation method of the high heat-resistant conductive