Diaphragm with piezoceramic coating and method for manufacturing same

Abstract

The embodiment of the present application provides a diaphragm with piezoelectric ceramic coating and a manufacturing method thereof, the method is as follows: after the polymer film is stretched, the polymer film is immersed in liquid ammonia to obtain a modified polymer film; piezoelectric ceramic powder is mixed with an adhesive and pre-pressed to obtain a pre-pressed block, the pre-pressed block is ground and sieved, and then is injected into a mold to be dry-pressed to obtain a blank, the blank is sintered at high temperature to obtain a piezoelectric ceramic body, the piezoelectric ceramic body is ground and sieved, and then is mixed with an adhesive solvent to form a piezoelectric ceramic powder suspension, the suspension is uniformly coated on the surface of the modified polymer film and heated, and the obtained diaphragm is polarized under an electric field to obtain the diaphragm with piezoelectric ceramic coating. The diaphragm with piezoelectric ceramic coating is manufactured by using the above method, a direct current pulse current is passed in to drive the piezoelectric ceramic particles on the diaphragm to vibrate, and the metal ion crystals on the diaphragm are broken by mechanical force, so that the crystal nucleus generated on the inner side of the battery pole piece can be effectively prevented.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of thin film material manufacturing, and particularly relates to a diaphragm with piezoelectric ceramic cladding and a manufacturing method thereof. BACKGROUND

[0002] With the rapid development of new energy technology, rechargeable batteries are widely used in various electrical appliances. In order to increase the strength of the diaphragm inside the battery pole piece and the ion migration efficiency, the rechargeable battery in the prior art method usually dopes aluminum oxide (Al2O3) in the diaphragm or lays aluminum oxide particles on the surface of the diaphragm. However, in the actual application process, the rechargeable battery using the traditional diaphragm will deposit and grow dendrites on the motor pole piece due to the change of the electrochemical properties of metal ions after repeated charging and discharging, which will seriously reduce the coulomb efficiency of the battery and will damage the diaphragm arranged inside the pole piece, that is, it will affect the charging efficiency and effective charging capacity of the rechargeable battery. At the same time, the generation of dendrites will significantly increase the charging heat, thereby seriously affecting the charging safety of the battery. Therefore, the diaphragm for the rechargeable battery in the prior art method has the problem of easy deposition of metal ions and generation of dendrites. SUMMARY

[0003] The embodiments of the present application provide a diaphragm with piezoelectric ceramic cladding and a manufacturing method thereof, aiming at solving the problem of easy deposition of metal ions and generation of dendrites of the diaphragm for the rechargeable battery in the prior art method.

[0004] The embodiments of the present application provide a manufacturing method of a diaphragm with piezoelectric ceramic cladding, which comprises the following steps:

[0005] The polymer thin film is longitudinally stretched at 165-235 DEG C, and the longitudinal stretching ratio is 4-9; then the polymer thin film is transversely stretched at 135-185 DEG C, and the stretching ratio is 2.5-5;

[0006] The stretched polymer thin film is immersed in liquid ammonia for 2-5 minutes to cool the polymer thin film and obtain a modified polymer thin film;

[0007] The piezoelectric ceramic powder and the binder are mixed and stirred uniformly according to the mass ratio (92-96):(2-5), and a pre-pressed block is obtained by pre-pressing under a pressure of 6-15 MPa. The pre-pressed block is ground and sieved, and then the sieved piezoelectric ceramic powder is injected into a mold and dry-pressed into a blank under a pressure of 8-22 MPa.

[0008] The blank is sintered at 900-1200 DEG C for 2-5 hours to obtain a piezoelectric ceramic body.

[0009] The piezoelectric ceramic body is ground and sieved, and the sieved piezoelectric ceramic powder is mixed with a viscous solvent to form a piezoelectric ceramic powder suspension.

[0010] The piezoelectric ceramic powder suspension is uniformly coated on the surface of the modified polymer film, and the modified polymer film is placed in an oven and the heating temperature is set to 95-110℃ to evaporate the viscous solvent, thus obtaining the initial diaphragm.

[0011] The initial diaphragm was polarized in an environment of 140-180℃ and under a polarized electric field with a fixed field strength direction to obtain a diaphragm with piezoelectric ceramic coating.

[0012] The method for manufacturing a diaphragm coated with piezoelectric ceramic, wherein the method for preparing the polymer film includes:

[0013] Polytetrafluoroethylene powder, petroleum ether, and silane coupling agent are mixed evenly in a reaction vessel at a mass ratio of 10:2.2:(0.2-0.5), and then sealed and cured at 40-50℃ for 6-8 hours to obtain a paste.

[0014] The above paste is flattened and stretched using a pressure bar under a pressure of 5-9.5 MPa to form a polymer sheet; the flattening and stretching temperature is 62-75℃.

[0015] The polymer sheet was placed in an oven and the heating temperature was set to 120-130℃ to dry and remove the petroleum ether.

[0016] The membrane is further fed into a radiation chamber for radiation cross-linking treatment to obtain a cross-linked polytetrafluoroethylene membrane.

[0017] A solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] dissolved in chlorobenzene at a concentration of 6-25 mg / mL was uniformly coated onto the cross-linked polytetrafluoroethylene membrane and then annealed to obtain a polymer film.

[0018] The method for manufacturing a diaphragm coated with piezoelectric ceramics, wherein the piezoelectric ceramic powder is obtained by mixing Pb3O4 powder, GeO2 powder, NiO powder, BaCO3 powder, ZrO2 powder, SnO2 powder and TiO2 powder in a mass ratio of (7.5-9.5):(0.2-0.5):(0.3-0.8):(0.6-1.8):(4.6-5):(3.2-3.8):(0.6-1.3).

[0019] The method for manufacturing a diaphragm coated with piezoelectric ceramics, wherein the viscous solvent is one or more combinations of isopropanol, cyclohexane, and methylcyclohexanol.

[0020] The method for manufacturing a diaphragm coated with piezoelectric ceramics, wherein the step of grinding the piezoelectric ceramic body and then sieving it includes: sieving the ground piezoelectric ceramic powder through a 1200-4000 mesh sieve.

[0021] The method for manufacturing a diaphragm coated with piezoelectric ceramics, wherein the piezoelectric ceramic powder in the piezoelectric ceramic powder suspension accounts for 0.8-2% by mass.

[0022] The method for manufacturing a diaphragm coated with piezoelectric ceramics, wherein the coating amount of the piezoelectric ceramic powder suspension on the surface of the modified polymer film is 45-200 ml / m. 2 .

[0023] The method for manufacturing a diaphragm coated with piezoelectric ceramics, wherein the electric field strength of the polarization electric field is 160-350 V / m.

[0024] The method for manufacturing a diaphragm coated with piezoelectric ceramics, wherein the polarization time is 20-45 minutes.

[0025] This invention also provides a diaphragm with piezoelectric ceramic coating, which is prepared by the above-described method for manufacturing a diaphragm with piezoelectric ceramic coating. The diaphragm includes a polymer film and piezoelectric ceramic particles deposited on the surface of the polymer film.

[0026] The polymer film is composed of a cross-linked polytetrafluoroethylene film and a poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] film laminated together; the piezoelectric ceramic particles are laid on both sides of the polymer film.

[0027] The polymer film has uniformly distributed through holes, the thickness of the polymer film is 20-140 μm, and the pore size of the through holes is 20-50 μm.

[0028] The piezoelectric ceramic particles are lead zirconate titanate ceramic particles, and the particle size of the piezoelectric ceramic particles is 0.5-25μm.

[0029] This invention provides a separator with piezoelectric ceramic coating and its manufacturing method. The method involves stretching a polymer film and immersing it in liquid ammonia for cooling to obtain a modified polymer film. Piezoelectric ceramic powder is mixed with a binder and pre-pressed to obtain a pre-pressed block. This block is then ground, sieved, and injected into a mold for dry pressing to obtain a blank. The blank is sintered at high temperature to obtain a piezoelectric ceramic body, which is then ground, sieved, and mixed with a viscous solvent to form a piezoelectric ceramic powder suspension. The suspension is uniformly coated onto the surface of the modified polymer film and heated. The resulting separator is then placed in an environment of 140-180°C and under a polarized electric field with a fixed field strength direction for polarization, resulting in a separator with piezoelectric ceramic coating. The above method involves stretching and cooling the polymer film to form through-holes. Piezoelectric ceramic particles are then laid on the surface of the polymer film to obtain a separator with piezoelectric ceramic coating. A DC pulse current is applied to drive the piezoelectric ceramic particles on the separator to vibrate, causing the separator to mechanically expand and contract, thereby breaking up metal ion crystals on the separator through mechanical force. This effectively prevents the formation of crystal nuclei on the inner side of the battery electrodes. Attached Figure Description

[0030] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 A flowchart illustrating a method for manufacturing a diaphragm coated with piezoelectric ceramics according to an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the cross-sectional structure of a diaphragm covered with piezoelectric ceramics, provided in an embodiment of the present invention. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0035] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0036] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0037] Please see Figure 1 , Figure 1 This is a flowchart illustrating a method for manufacturing a separator with piezoelectric ceramic coating according to an embodiment of the present invention. This separator manufacturing method is used to produce the separator with piezoelectric ceramic coating as described in this application embodiment. As shown, the method for manufacturing the separator with piezoelectric ceramic coating includes steps S110-S170.

[0038] S110. The polymer film is longitudinally stretched at 165-235℃ with a longitudinal stretching ratio of 4-9; then it is transversely stretched at 135-185℃ with a stretching ratio of 2.5-5.

[0039] The polymer film can be longitudinally stretched at 165-235°C, with a stretching ratio of 4-9, preferably 6-7; then, the film is transversely stretched at 135-185°C, with a stretching ratio of 2.5-5, preferably 3.5-4.5. Specifically, the polymer film can be polytetrafluoroethylene (PTFE). This stretching process creates tiny through-holes in the polymer film, stretching the fibers and forming the gaps between them.

[0040] Specifically, the preparation method of the polymer film includes the following steps: Polytetrafluoroethylene powder, petroleum ether, and silane coupling agent are mixed evenly in a reaction vessel at a mass ratio of 10:2.2:(0.2-0.5), and cured in a sealed container at 40-50°C for 6-8 hours to obtain a paste; the paste is flattened and stretched under a pressure of 5-9.5 MPa using a pressure bar to form a polymer sheet; the flattening and stretching temperature is 62-75°C; the polymer sheet is placed in an oven and the heating temperature is set to 120-130°C to dry and remove the petroleum ether; it is further sent to a radiation chamber for radiation crosslinking treatment to obtain a crosslinked polytetrafluoroethylene film; a solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] dissolved in chlorobenzene at a concentration of 6-25 mg / mL is uniformly coated onto the crosslinked polytetrafluoroethylene film and annealed to obtain the polymer film.

[0041] Polytetrafluoroethylene (PTFE) powder, petroleum ether, and KH-550 silane coupling agent (γ-aminopropyltriethoxysilane) are mixed in a predetermined mass ratio and heated to prepare a paste. This paste is then flattened and stretched under a pressure of 5-9.5 MPa using multi-stage pressure bars to form polymer sheets. The pressing pressure and temperature of the multi-stage pressure bars gradually increase. For example, the first-stage pressure is 5.5 MPa and the pressing temperature is 62°C; the second-stage pressure is 5.8 MPa and the pressing temperature is 64°C; the third-stage pressure is 6.2 MPa and the pressing temperature is 66°C, and so on. The polymer sheets are then heated to remove the petroleum ether and then placed in a radiation chamber for radiation crosslinking treatment. The radiation metering is controlled at 6-30 kGy to obtain a crosslinked PTFE film. The poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] dissolved in chlorobenzene is then uniformly coated onto a cross-linked polytetrafluoroethylene film and annealed at 105-125℃ for 7-10 minutes to obtain a polymer film.

[0042] S120. Immerse the stretched polymer film in liquid ammonia for 2-5 minutes to cool the polymer film and obtain a modified polymer film.

[0043] Furthermore, the stretched polymer film is placed in liquid ammonia for 2-5 minutes to cool and modify the polymer film, and to tighten and shape the through-holes in the polymer film, so as to prevent the through-holes from reclosing due to film shrinkage. After soaking in liquid ammonia, the modified polymer film can be obtained.

[0044] S130. Mix the piezoelectric ceramic powder and binder at a mass ratio of (92-96):(2-5) and stir evenly. Pre-press the mixture under a pressure of 6-15MPa to obtain a pre-pressed block. Grind the pre-pressed block, sieve it, inject it into a mold, and dry press it under a pressure of 8-22MPa to obtain a blank.

[0045] The piezoelectric ceramic powder and binder are mixed and stirred evenly at a certain mass ratio. The piezoelectric ceramic powder can be PZT powder. For example, it can be obtained by mixing Pb3O4 powder, GeO2 powder, NiO powder, BaCO3 powder, ZrO2 powder, SnO2 powder, and TiO2 powder in a mass ratio of (7.5-9.5):(0.2-0.5):(0.3-0.8):(0.6-1.8):(4.6-5):(3.2-3.8):(0.6-1.3). The binder is obtained by mixing glycerin, alcohol, and distilled water in a mass ratio of 16:4:80. A lower pressure is first used for pre-pressing, followed by higher pressure for dry pressing to obtain the blank.

[0046] S140. The blank is sintered at 900-1200℃ for 2-5 hours to obtain a piezoelectric ceramic body.

[0047] The blank is sintered at high temperature to obtain a piezoelectric ceramic body. The blank can be heated from room temperature to 900-1000℃ for 0.5 hours, and then heated from the current temperature to 1001-1200℃ for 1.5-4.5 hours to complete the sintering operation.

[0048] S150. The piezoelectric ceramic body is ground and then sieved. The sieved piezoelectric ceramic powder is mixed with a viscous solvent to form a piezoelectric ceramic powder suspension.

[0049] The piezoelectric ceramic body is ground into powder, and the ground ceramic particles are sieved, specifically the piezoelectric ceramic powder obtained by sieving through a 1200-4000 mesh sieve. The sieved piezoelectric ceramic powder is then mixed with a viscous solvent to obtain a piezoelectric ceramic powder suspension; wherein the viscous solvent is one or a combination of isopropanol, cyclohexane, and methylcyclohexanol. The mass percentage of piezoelectric ceramic powder in the piezoelectric ceramic powder suspension is 0.8-2%.

[0050] S160. The piezoelectric ceramic powder suspension is uniformly coated on the surface of the modified polymer film, and the modified polymer film is placed in an oven and the heating temperature is set to 95-110℃ to allow the viscous solvent to evaporate, thus obtaining the initial diaphragm.

[0051] A piezoelectric ceramic powder suspension is uniformly coated onto both surfaces of a modified polymer film. The modified polymer film is then placed in an oven and heated to 95-110°C to evaporate the viscous solvent. Specifically, the piezoelectric ceramic powder suspension can be uniformly coated onto both surfaces of the modified polymer film simultaneously and then heated. Alternatively, the piezoelectric ceramic powder suspension can be uniformly coated onto one surface of the modified polymer film and heated, followed by uniform coating onto the other surface and heating. After heating to evaporate the viscous solvent, the initial separator is obtained. The coating amount of the piezoelectric ceramic powder suspension on the surface of the modified polymer film is 45-200 ml / m. 2 .

[0052] S170. The initial diaphragm is placed in an environment of 140-180℃ and a polarized electric field with a fixed field strength direction for polarization to obtain a diaphragm with piezoelectric ceramic coating.

[0053] The initial diaphragm obtained in the above steps is placed in a thermal environment of 140-180℃ and a polarization electric field with a fixed field strength direction for polarization. Specifically, the electric field strength of the polarization electric field is 160-350V / m, and the polarization time is 20-45 minutes. After polarization is completed, a diaphragm with piezoelectric ceramic coating can be obtained.

[0054] The diaphragm with piezoelectric ceramic coating prepared by the above method is as follows: Figure 2 As shown, the diaphragm with piezoelectric ceramic coating includes a polymer film 1 and piezoelectric ceramic particles 2 deposited on the surface of the polymer film 1. The polymer film 1 is formed by bonding a cross-linked polytetrafluoroethylene film 11 and a poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] film 12. The piezoelectric ceramic particles 2 are deposited on both sides of the polymer film 1. Through-holes 101 are uniformly distributed on the polymer film 1. The thickness of the polymer film 1 is 20-140 μm, and the pore size of the through-holes 101 is 20-50 μm. The piezoelectric ceramic particles 2 are lead zirconate titanate ceramic particles with a particle size of 0.5-25 μm. The overall thickness ratio of the cross-linked polytetrafluoroethylene film 11 to the polymer film 1 is 0.55-0.7.

[0055] The following comparison of multiple embodiments illustrates the specific implementation process and beneficial effects of the solution.

[0056] Example 1

[0057] The polymer film was longitudinally stretched at 210°C with a stretch ratio of 6.8; then it was transversely stretched at 170°C with a stretch ratio of 4.

[0058] Specifically, the preparation method of the polymer film includes the following steps: Polytetrafluoroethylene powder, petroleum ether, and KH-550 silane coupling agent (γ-aminopropyltriethoxysilane) are mixed evenly in a reaction vessel at a mass ratio of 10:1.8:0.3, and the mixture is sealed and cured at 45°C for 6.5 hours to obtain a paste. The paste is then flattened and stretched using an eight-stage pressure bar to obtain a polymer sheet. The first stage pressure bar has a pressing pressure of 5.5 MPa and a pressing temperature of 62°C; the second stage pressure bar has a pressing pressure of 5.8 MPa. a. The pressing temperature is 64℃; the pressing pressure of the third-stage pressing rod is 6.2MPa and the pressing temperature is 66℃; the pressing pressure of the fourth-stage pressing rod is 6.8MPa and the pressing temperature is 68℃; the pressing pressure of the fifth-stage pressing rod is 7.4MPa and the pressing temperature is 70℃; the pressing pressure of the sixth-stage pressing rod is 8MPa and the pressing temperature is 72℃; the pressing pressure of the seventh-stage pressing rod is 8.8MPa and the pressing temperature is 74℃; the pressing pressure of the eighth-stage pressing rod is 9.5MPa and the pressing temperature is 75℃. The polymer sheet was placed in an oven and heated to 125°C to remove petroleum ether; it was then further subjected to radiation crosslinking treatment in a radiation chamber at an intensity of 12 kGy to obtain a crosslinked polytetrafluoroethylene membrane; a solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] dissolved in chlorobenzene at a concentration of 15 mg / mL was uniformly coated onto the crosslinked polytetrafluoroethylene membrane and annealed at 108°C for 8 minutes to obtain a polymer film.

[0059] Furthermore, the stretched polymer film was placed in liquid ammonia for 4 minutes to cool and modify the polymer film.

[0060] Lead zirconate titanate powder and binder were mixed and stirred evenly at a mass ratio of 95:5, and pre-pressed under 10 MPa pressure to obtain pre-pressed blocks. The pre-pressed blocks were ground, sieved, and then injected into a mold and dry-pressed under 18 MPa pressure to obtain blanks. The lead zirconate titanate powder was obtained by mixing Pb3O4 powder, GeO2 powder, NiO powder, BaCO3 powder, ZrO2 powder, SnO2 powder, and TiO2 powder in a mass ratio of 8:0.3:0.5:1.5:5:3.6:1.1, and the binder was obtained by mixing glycerol, alcohol, and distilled water in a mass ratio of 16:4:80.

[0061] The blank is sintered at high temperature to obtain a piezoelectric ceramic body. The blank is first heated from room temperature to 960°C and held for 0.5 hours, and then heated from the current temperature to 1120°C and held for 3.5 hours to complete the sintering operation.

[0062] The piezoelectric ceramic body is ground into powder, and the resulting powder is sieved through a 2500-mesh sieve. The sieved piezoelectric ceramic powder is then mixed with a viscous solvent to obtain a piezoelectric ceramic powder suspension; wherein the viscous solvent is cyclohexane. The mass percentage of piezoelectric ceramic powder in the suspension is 1.5%.

[0063] A piezoelectric ceramic powder suspension was uniformly coated onto both surfaces of a modified polymer film. The modified polymer film was then placed in an oven and heated to 98°C to allow the viscous solvent to evaporate. The amount of piezoelectric ceramic powder suspension applied to the modified polymer film surface was 120 ml / m². 2 .

[0064] The initial diaphragm obtained in the above steps is placed in a thermal environment of 165°C and a polarization electric field with a fixed field strength direction for polarization. Specifically, the electric field strength of the polarization electric field is 220V / m, and the polarization time is 30 minutes. After polarization is completed, a diaphragm with piezoelectric ceramic coating can be obtained.

[0065] Example 2

[0066] The polymer film was longitudinally stretched at 210°C with a stretch ratio of 6.8; then it was transversely stretched at 170°C with a stretch ratio of 4.

[0067] Specifically, the preparation method of the polymer film includes the following steps: Polytetrafluoroethylene powder, petroleum ether, and KH-550 silane coupling agent (γ-aminopropyltriethoxysilane) are mixed evenly in a reaction vessel at a mass ratio of 10:1.8:0.3, and the mixture is sealed and cured at 45°C for 6.5 hours to obtain a paste. The paste is then flattened and stretched using an eight-stage pressure bar to obtain a polymer sheet. The first stage pressure bar has a pressing pressure of 5.5 MPa and a pressing temperature of 62°C; the second stage pressure bar has a pressing pressure of 5.8 MPa. a. The pressing temperature is 64℃; the pressing pressure of the third-stage pressing rod is 6.2MPa and the pressing temperature is 66℃; the pressing pressure of the fourth-stage pressing rod is 6.8MPa and the pressing temperature is 68℃; the pressing pressure of the fifth-stage pressing rod is 7.4MPa and the pressing temperature is 70℃; the pressing pressure of the sixth-stage pressing rod is 8MPa and the pressing temperature is 72℃; the pressing pressure of the seventh-stage pressing rod is 8.8MPa and the pressing temperature is 74℃; the pressing pressure of the eighth-stage pressing rod is 9.5MPa and the pressing temperature is 75℃. The polymer sheet was placed in an oven and heated to 125°C to remove petroleum ether; it was then further subjected to radiation crosslinking treatment in a radiation chamber at an intensity of 12 kGy to obtain a crosslinked polytetrafluoroethylene membrane; a solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] dissolved in chlorobenzene at a concentration of 15 mg / mL was uniformly coated onto the crosslinked polytetrafluoroethylene membrane and annealed at 108°C for 8 minutes to obtain a polymer film.

[0068] Furthermore, the stretched polymer film was placed in liquid ammonia for 4 minutes to cool and modify the polymer film.

[0069] Lead zirconate titanate powder and binder were mixed and stirred evenly at a mass ratio of 95:5, and pre-pressed under 10 MPa pressure to obtain pre-pressed blocks. The pre-pressed blocks were ground, sieved, and then injected into a mold and dry-pressed under 18 MPa pressure to obtain blanks. The lead zirconate titanate powder was obtained by mixing Pb3O4 powder, GeO2 powder, NiO powder, BaCO3 powder, ZrO2 powder, SnO2 powder, and TiO2 powder at a mass ratio of 9:0.2:0.3:1.2:4.8:3.5:1, and the binder was obtained by mixing glycerol, alcohol, and distilled water at a mass ratio of 16:4:80.

[0070] The blank is sintered at high temperature to obtain a piezoelectric ceramic body. The blank is first heated from room temperature to 960°C and held for 0.5 hours, and then heated from the current temperature to 1120°C and held for 3.5 hours to complete the sintering operation.

[0071] The piezoelectric ceramic body is ground into powder, and the resulting powder is sieved through a 2500-mesh sieve. The sieved piezoelectric ceramic powder is then mixed with a viscous solvent to obtain a piezoelectric ceramic powder suspension; wherein the viscous solvent is cyclohexane. The mass percentage of piezoelectric ceramic powder in the suspension is 1.5%.

[0072] A piezoelectric ceramic powder suspension was uniformly coated onto both surfaces of a modified polymer film. The modified polymer film was then placed in an oven and heated to 98°C to allow the viscous solvent to evaporate. The amount of piezoelectric ceramic powder suspension applied to the modified polymer film surface was 120 ml / m². 2 .

[0073] The initial diaphragm obtained in the above steps is placed in a thermal environment of 165°C and a polarization electric field with a fixed field strength direction for polarization. Specifically, the electric field strength of the polarization electric field is 220V / m, and the polarization time is 30 minutes. After polarization is completed, a diaphragm with piezoelectric ceramic coating can be obtained.

[0074] Example 3

[0075] The polymer film was longitudinally stretched at 210°C with a stretch ratio of 6.8; then it was transversely stretched at 170°C with a stretch ratio of 4.

[0076] Specifically, the preparation method of the polymer film includes the following steps: Polytetrafluoroethylene powder, petroleum ether, and KH-550 silane coupling agent (γ-aminopropyltriethoxysilane) are mixed evenly in a reaction vessel at a mass ratio of 10:1.8:0.3, and the mixture is sealed and cured at 45°C for 6.5 hours to obtain a paste. The paste is then flattened and stretched using an eight-stage pressure bar to obtain a polymer sheet. The first stage pressure bar has a pressing pressure of 5.5 MPa and a pressing temperature of 62°C; the second stage pressure bar has a pressing pressure of 5.8 MPa. a. The pressing temperature is 64℃; the pressing pressure of the third-stage pressing rod is 6.2MPa and the pressing temperature is 66℃; the pressing pressure of the fourth-stage pressing rod is 6.8MPa and the pressing temperature is 68℃; the pressing pressure of the fifth-stage pressing rod is 7.4MPa and the pressing temperature is 70℃; the pressing pressure of the sixth-stage pressing rod is 8MPa and the pressing temperature is 72℃; the pressing pressure of the seventh-stage pressing rod is 8.8MPa and the pressing temperature is 74℃; the pressing pressure of the eighth-stage pressing rod is 9.5MPa and the pressing temperature is 75℃. The polymer sheet was placed in an oven and heated to 125°C to remove petroleum ether; it was then further subjected to radiation crosslinking treatment in a radiation chamber at an intensity of 12 kGy to obtain a crosslinked polytetrafluoroethylene membrane; a solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] dissolved in chlorobenzene at a concentration of 15 mg / mL was uniformly coated onto the crosslinked polytetrafluoroethylene membrane and annealed at 108°C for 8 minutes to obtain a polymer film.

[0077] Furthermore, the stretched polymer film was placed in liquid ammonia for 4 minutes to cool and modify the polymer film.

[0078] Lead zirconate titanate powder and binder were mixed and stirred evenly at a mass ratio of 95:5, and pre-pressed under 10 MPa pressure to obtain pre-pressed blocks. The pre-pressed blocks were ground, sieved, and then injected into a mold and dry-pressed under 18 MPa pressure to obtain blanks. The lead zirconate titanate powder was obtained by mixing Pb3O4 powder, GeO2 powder, NiO powder, BaCO3 powder, ZrO2 powder, SnO2 powder, and TiO2 powder at a mass ratio of 8:0.4:0.6:1.2:5:3.6:1, and the binder was obtained by mixing glycerol, alcohol, and distilled water at a mass ratio of 16:4:80.

[0079] The blank is sintered at high temperature to obtain a piezoelectric ceramic body. The blank is first heated from room temperature to 960°C and held for 0.5 hours, and then heated from the current temperature to 1120°C and held for 3.5 hours to complete the sintering operation.

[0080] The piezoelectric ceramic body is ground into powder, and the resulting powder is sieved through a 2500-mesh sieve. The sieved piezoelectric ceramic powder is then mixed with a viscous solvent to obtain a piezoelectric ceramic powder suspension; wherein the viscous solvent is cyclohexane. The mass percentage of piezoelectric ceramic powder in the suspension is 1.5%.

[0081] A piezoelectric ceramic powder suspension was uniformly coated onto both surfaces of a modified polymer film. The modified polymer film was then placed in an oven and heated to 98°C to allow the viscous solvent to evaporate. The amount of piezoelectric ceramic powder suspension applied to the modified polymer film surface was 120 ml / m². 2 .

[0082] The initial diaphragm obtained in the above steps is placed in a thermal environment of 165°C and a polarization electric field with a fixed field strength direction for polarization. Specifically, the electric field strength of the polarization electric field is 220V / m, and the polarization time is 30 minutes. After polarization is completed, a diaphragm with piezoelectric ceramic coating can be obtained.

[0083] Example 4

[0084] The polymer film was longitudinally stretched at 210°C with a stretch ratio of 6.8; then it was transversely stretched at 170°C with a stretch ratio of 4.

[0085] Specifically, the preparation method of the polymer film includes the following steps: Polytetrafluoroethylene powder, petroleum ether, and KH-550 silane coupling agent (γ-aminopropyltriethoxysilane) are mixed evenly in a reaction vessel at a mass ratio of 10:1.8:0.3, and the mixture is sealed and cured at 45°C for 6.5 hours to obtain a paste. The paste is then flattened and stretched using a ten-stage pressing rod to obtain a polymer sheet. The pressing pressure of the first stage is 5.5 MPa, and the pressing temperature is 62°C; the pressing pressure of the second stage is 5.8 MPa, and the pressing temperature is 64°C; the pressing pressure of the third stage is 6.2 MPa. a. The pressing temperature is 66℃; the pressing pressure of the fourth-stage pressing rod is 6.5MPa and the pressing temperature is 67℃; the pressing pressure of the fifth-stage pressing rod is 6.8MPa and the pressing temperature is 68℃; the pressing pressure of the sixth-stage pressing rod is 7.2MPa and the pressing temperature is 69℃; the pressing pressure of the seventh-stage pressing rod is 7.5MPa and the pressing temperature is 70℃; the pressing pressure of the eighth-stage pressing rod is 8MPa and the pressing temperature is 72℃; the pressing pressure of the ninth-stage pressing rod is 8.8MPa and the pressing temperature is 74℃; the pressing pressure of the tenth-stage pressing rod is 9.5MPa and the pressing temperature is 75℃. The polymer sheet was placed in an oven and heated to 125°C to remove petroleum ether; it was then further subjected to radiation crosslinking treatment in a radiation chamber at an intensity of 12 kGy to obtain a crosslinked polytetrafluoroethylene membrane; a solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] dissolved in chlorobenzene at a concentration of 15 mg / mL was uniformly coated onto the crosslinked polytetrafluoroethylene membrane and annealed at 108°C for 8 minutes to obtain a polymer film.

[0086] Furthermore, the stretched polymer film was placed in liquid ammonia for 4 minutes to cool and modify the polymer film.

[0087] Lead zirconate titanate powder and binder were mixed and stirred evenly at a mass ratio of 95:5, and pre-pressed under 10 MPa pressure to obtain pre-pressed blocks. The pre-pressed blocks were ground, sieved, and then injected into a mold and dry-pressed under 18 MPa pressure to obtain blanks. The lead zirconate titanate powder was obtained by mixing Pb3O4 powder, GeO2 powder, NiO powder, BaCO3 powder, ZrO2 powder, SnO2 powder, and TiO2 powder in a mass ratio of 8:0.3:0.5:1.5:5:3.6:1.1, and the binder was obtained by mixing glycerol, alcohol, and distilled water in a mass ratio of 16:4:80.

[0088] The blank is sintered at high temperature to obtain a piezoelectric ceramic body. The blank is first heated from room temperature to 960°C and held for 0.5 hours, and then heated from the current temperature to 1120°C and held for 3.5 hours to complete the sintering operation.

[0089] The piezoelectric ceramic body is ground into powder, and the resulting powder is sieved through a 2500-mesh sieve. The sieved piezoelectric ceramic powder is then mixed with a viscous solvent to obtain a piezoelectric ceramic powder suspension; wherein the viscous solvent is cyclohexane. The mass percentage of piezoelectric ceramic powder in the suspension is 1.5%.

[0090] A piezoelectric ceramic powder suspension was uniformly coated onto both surfaces of a modified polymer film. The modified polymer film was then placed in an oven and heated to 98°C to allow the viscous solvent to evaporate. The amount of piezoelectric ceramic powder suspension applied to the modified polymer film surface was 120 ml / m². 2 .

[0091] The initial diaphragm obtained in the above steps is placed in a thermal environment of 165°C and a polarization electric field with a fixed field strength direction for polarization. Specifically, the electric field strength of the polarization electric field is 220V / m, and the polarization time is 30 minutes. After polarization is completed, a diaphragm with piezoelectric ceramic coating can be obtained.

[0092] Example 5

[0093] The polymer film was longitudinally stretched at 210°C with a stretch ratio of 6.8; then it was transversely stretched at 170°C with a stretch ratio of 4.

[0094] Specifically, the preparation method of the polymer film includes the following steps: Polytetrafluoroethylene powder, petroleum ether, and KH-550 silane coupling agent (γ-aminopropyltriethoxysilane) are mixed evenly in a reaction vessel at a mass ratio of 10:1.8:0.3, and the mixture is sealed and cured at 45°C for 6.5 hours to obtain a paste. The paste is then flattened and stretched using a ten-stage pressing rod to obtain a polymer sheet. The pressing pressure of the first stage is 5.5 MPa, and the pressing temperature is 62°C; the pressing pressure of the second stage is 5.8 MPa, and the pressing temperature is 64°C; the pressing pressure of the third stage is 6.2 MPa. a. The pressing temperature is 66℃; the pressing pressure of the fourth-stage pressing rod is 6.5MPa and the pressing temperature is 67℃; the pressing pressure of the fifth-stage pressing rod is 6.8MPa and the pressing temperature is 68℃; the pressing pressure of the sixth-stage pressing rod is 7.2MPa and the pressing temperature is 69℃; the pressing pressure of the seventh-stage pressing rod is 7.5MPa and the pressing temperature is 70℃; the pressing pressure of the eighth-stage pressing rod is 8MPa and the pressing temperature is 72℃; the pressing pressure of the ninth-stage pressing rod is 8.8MPa and the pressing temperature is 74℃; the pressing pressure of the tenth-stage pressing rod is 9.5MPa and the pressing temperature is 75℃. The polymer sheet was placed in an oven and heated to 125°C to remove petroleum ether; it was then further subjected to radiation crosslinking treatment in a radiation chamber at an intensity of 12 kGy to obtain a crosslinked polytetrafluoroethylene membrane; a solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] dissolved in chlorobenzene at a concentration of 15 mg / mL was uniformly coated onto the crosslinked polytetrafluoroethylene membrane and annealed at 108°C for 8 minutes to obtain a polymer film.

[0095] Furthermore, the stretched polymer film was placed in liquid ammonia for 4 minutes to cool and modify the polymer film.

[0096] Lead zirconate titanate powder and binder were mixed and stirred evenly at a mass ratio of 95:5, and pre-pressed under 10 MPa pressure to obtain pre-pressed blocks. The pre-pressed blocks were ground, sieved, and then injected into a mold and dry-pressed under 18 MPa pressure to obtain blanks. The lead zirconate titanate powder was obtained by mixing Pb3O4 powder, GeO2 powder, NiO powder, BaCO3 powder, ZrO2 powder, SnO2 powder, and TiO2 powder at a mass ratio of 9:0.2:0.3:1.2:4.8:3.5:1, and the binder was obtained by mixing glycerol, alcohol, and distilled water at a mass ratio of 16:4:80.

[0097] The blank is sintered at high temperature to obtain a piezoelectric ceramic body. The blank is first heated from room temperature to 960°C and held for 0.5 hours, and then heated from the current temperature to 1120°C and held for 3.5 hours to complete the sintering operation.

[0098] The piezoelectric ceramic body is ground into powder, and the resulting powder is sieved through a 2500-mesh sieve. The sieved piezoelectric ceramic powder is then mixed with a viscous solvent to obtain a piezoelectric ceramic powder suspension; wherein the viscous solvent is cyclohexane. The mass percentage of piezoelectric ceramic powder in the suspension is 1.5%.

[0099] A piezoelectric ceramic powder suspension was uniformly coated onto both surfaces of a modified polymer film. The modified polymer film was then placed in an oven and heated to 98°C to allow the viscous solvent to evaporate. The amount of piezoelectric ceramic powder suspension applied to the modified polymer film surface was 120 ml / m². 2 .

[0100] The initial diaphragm obtained in the above steps is placed in a thermal environment of 165°C and a polarization electric field with a fixed field strength direction for polarization. Specifically, the electric field strength of the polarization electric field is 220V / m, and the polarization time is 30 minutes. After polarization is completed, a diaphragm with piezoelectric ceramic coating can be obtained.

[0101] Example 6

[0102] The polymer film was longitudinally stretched at 210°C with a stretch ratio of 6.8; then it was transversely stretched at 170°C with a stretch ratio of 4.

[0103] Specifically, the preparation method of the polymer film includes the following steps: Polytetrafluoroethylene powder, petroleum ether, and KH-550 silane coupling agent (γ-aminopropyltriethoxysilane) are mixed evenly in a reaction vessel at a mass ratio of 10:1.8:0.3, and the mixture is sealed and cured at 45°C for 6.5 hours to obtain a paste. The paste is then flattened and stretched using a ten-stage pressing rod to obtain a polymer sheet. The pressing pressure of the first stage is 5.5 MPa, and the pressing temperature is 62°C; the pressing pressure of the second stage is 5.8 MPa, and the pressing temperature is 64°C; the pressing pressure of the third stage is 6.2 MPa. a. The pressing temperature is 66℃; the pressing pressure of the fourth-stage pressing rod is 6.5MPa and the pressing temperature is 67℃; the pressing pressure of the fifth-stage pressing rod is 6.8MPa and the pressing temperature is 68℃; the pressing pressure of the sixth-stage pressing rod is 7.2MPa and the pressing temperature is 69℃; the pressing pressure of the seventh-stage pressing rod is 7.5MPa and the pressing temperature is 70℃; the pressing pressure of the eighth-stage pressing rod is 8MPa and the pressing temperature is 72℃; the pressing pressure of the ninth-stage pressing rod is 8.8MPa and the pressing temperature is 74℃; the pressing pressure of the tenth-stage pressing rod is 9.5MPa and the pressing temperature is 75℃. The polymer sheet was placed in an oven and heated to 125°C to remove petroleum ether; it was then further subjected to radiation crosslinking treatment in a radiation chamber at an intensity of 12 kGy to obtain a crosslinked polytetrafluoroethylene membrane; a solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] dissolved in chlorobenzene at a concentration of 15 mg / mL was uniformly coated onto the crosslinked polytetrafluoroethylene membrane and annealed at 108°C for 8 minutes to obtain a polymer film.

[0104] Furthermore, the stretched polymer film was placed in liquid ammonia for 4 minutes to cool and modify the polymer film.

[0105] Lead zirconate titanate powder and binder were mixed and stirred evenly at a mass ratio of 95:5, and pre-pressed under 10 MPa pressure to obtain pre-pressed blocks. The pre-pressed blocks were ground, sieved, and then injected into a mold and dry-pressed under 18 MPa pressure to obtain blanks. The lead zirconate titanate powder was obtained by mixing Pb3O4 powder, GeO2 powder, NiO powder, BaCO3 powder, ZrO2 powder, SnO2 powder, and TiO2 powder at a mass ratio of 8:0.4:0.6:1.2:5:3.6:1, and the binder was obtained by mixing glycerol, alcohol, and distilled water at a mass ratio of 16:4:80.

[0106] The blank is sintered at high temperature to obtain a piezoelectric ceramic body. The blank is first heated from room temperature to 960°C and held for 0.5 hours, and then heated from the current temperature to 1120°C and held for 3.5 hours to complete the sintering operation.

[0107] The piezoelectric ceramic body is ground into powder, and the resulting powder is sieved through a 2500-mesh sieve. The sieved piezoelectric ceramic powder is then mixed with a viscous solvent to obtain a piezoelectric ceramic powder suspension; wherein the viscous solvent is cyclohexane. The mass percentage of piezoelectric ceramic powder in the suspension is 1.5%.

[0108] A piezoelectric ceramic powder suspension was uniformly coated onto both surfaces of a modified polymer film. The modified polymer film was then placed in an oven and heated to 98°C to allow the viscous solvent to evaporate. The amount of piezoelectric ceramic powder suspension applied to the modified polymer film surface was 120 ml / m². 2 .

[0109] The initial diaphragm obtained in the above steps is placed in a thermal environment of 165°C and a polarization electric field with a fixed field strength direction for polarization. Specifically, the electric field strength of the polarization electric field is 220V / m, and the polarization time is 30 minutes. After polarization is completed, a diaphragm with piezoelectric ceramic coating can be obtained.

[0110] Example 7

[0111] The polymer film was longitudinally stretched at 210°C with a stretch ratio of 6.8; then it was transversely stretched at 170°C with a stretch ratio of 4.

[0112] Specifically, the preparation method of the polymer film includes the following steps: Polytetrafluoroethylene powder, petroleum ether, and KH-550 silane coupling agent (γ-aminopropyltriethoxysilane) are mixed evenly in a reaction vessel at a mass ratio of 10:1.8:0.3, and the mixture is sealed and cured at 45°C for 6.5 hours to obtain a paste. The paste is then flattened and stretched using a ten-stage pressing rod to obtain a polymer sheet. The pressing pressure of the first stage is 5.5 MPa, and the pressing temperature is 62°C; the pressing pressure of the second stage is 5.8 MPa, and the pressing temperature is 64°C; the pressing pressure of the third stage is 6.2 MPa. a. The pressing temperature is 66℃; the pressing pressure of the fourth-stage pressing rod is 6.5MPa and the pressing temperature is 67℃; the pressing pressure of the fifth-stage pressing rod is 6.8MPa and the pressing temperature is 68℃; the pressing pressure of the sixth-stage pressing rod is 7.2MPa and the pressing temperature is 69℃; the pressing pressure of the seventh-stage pressing rod is 7.5MPa and the pressing temperature is 70℃; the pressing pressure of the eighth-stage pressing rod is 8MPa and the pressing temperature is 72℃; the pressing pressure of the ninth-stage pressing rod is 8.8MPa and the pressing temperature is 74℃; the pressing pressure of the tenth-stage pressing rod is 9.5MPa and the pressing temperature is 75℃. The polymer sheet was placed in an oven and heated to 125°C to remove petroleum ether. It was then further subjected to radiation crosslinking treatment in a radiation chamber at an intensity of 12 kGy to obtain a crosslinked polytetrafluoroethylene (PTFE) membrane. A solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] dissolved in chlorobenzene at a concentration of 10 mg / mL was uniformly coated onto the crosslinked PTFE membrane and annealed at 108°C for 8 minutes to obtain a polymer film.

[0113] Furthermore, the stretched polymer film was placed in liquid ammonia for 4 minutes to cool and modify the polymer film.

[0114] Lead zirconate titanate powder and binder were mixed and stirred evenly at a mass ratio of 95:5, and pre-pressed under 10 MPa pressure to obtain pre-pressed blocks. The pre-pressed blocks were ground, sieved, and then injected into a mold and dry-pressed under 18 MPa pressure to obtain blanks. The lead zirconate titanate powder was obtained by mixing Pb3O4 powder, GeO2 powder, NiO powder, BaCO3 powder, ZrO2 powder, SnO2 powder, and TiO2 powder in a mass ratio of 8:0.3:0.5:1.5:5:3.6:1.1, and the binder was obtained by mixing glycerol, alcohol, and distilled water in a mass ratio of 16:4:80.

[0115] The blank is sintered at high temperature to obtain a piezoelectric ceramic body. The blank is first heated from room temperature to 960°C and held for 0.5 hours, and then heated from the current temperature to 1120°C and held for 3.5 hours to complete the sintering operation.

[0116] The piezoelectric ceramic body is ground into powder, and the resulting powder is sieved through a 2500-mesh sieve. The sieved piezoelectric ceramic powder is then mixed with a viscous solvent to obtain a piezoelectric ceramic powder suspension; wherein the viscous solvent is cyclohexane. The mass percentage of piezoelectric ceramic powder in the suspension is 1.5%.

[0117] A piezoelectric ceramic powder suspension was uniformly coated onto both surfaces of a modified polymer film. The modified polymer film was then placed in an oven and heated to 98°C to allow the viscous solvent to evaporate. The amount of piezoelectric ceramic powder suspension applied to the modified polymer film surface was 120 ml / m². 2 .

[0118] The initial diaphragm obtained in the above steps is placed in a thermal environment of 165°C and a polarization electric field with a fixed field strength direction for polarization. Specifically, the electric field strength of the polarization electric field is 220V / m, and the polarization time is 30 minutes. After polarization is completed, a diaphragm with piezoelectric ceramic coating can be obtained.

[0119] Example 8

[0120] The polymer film was longitudinally stretched at 210°C with a stretch ratio of 6.8; then it was transversely stretched at 170°C with a stretch ratio of 4.

[0121] Specifically, the preparation method of the polymer film includes the following steps: Polytetrafluoroethylene powder, petroleum ether, and KH-550 silane coupling agent (γ-aminopropyltriethoxysilane) are mixed evenly in a reaction vessel at a mass ratio of 10:1.8:0.3, and the mixture is sealed and cured at 45°C for 6.5 hours to obtain a paste. The paste is then flattened and stretched using a ten-stage pressing rod to obtain a polymer sheet. The pressing pressure of the first stage is 5.5 MPa, and the pressing temperature is 62°C; the pressing pressure of the second stage is 5.8 MPa, and the pressing temperature is 64°C; the pressing pressure of the third stage is 6.2 MPa. a. The pressing temperature is 66℃; the pressing pressure of the fourth-stage pressing rod is 6.5MPa and the pressing temperature is 67℃; the pressing pressure of the fifth-stage pressing rod is 6.8MPa and the pressing temperature is 68℃; the pressing pressure of the sixth-stage pressing rod is 7.2MPa and the pressing temperature is 69℃; the pressing pressure of the seventh-stage pressing rod is 7.5MPa and the pressing temperature is 70℃; the pressing pressure of the eighth-stage pressing rod is 8MPa and the pressing temperature is 72℃; the pressing pressure of the ninth-stage pressing rod is 8.8MPa and the pressing temperature is 74℃; the pressing pressure of the tenth-stage pressing rod is 9.5MPa and the pressing temperature is 75℃. The polymer sheet was placed in an oven and heated to 125°C to remove petroleum ether. It was then further subjected to radiation crosslinking treatment in a radiation chamber at an intensity of 12 kGy to obtain a crosslinked polytetrafluoroethylene (PTFE) membrane. A solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] dissolved in chlorobenzene at a concentration of 10 mg / mL was uniformly coated onto the crosslinked PTFE membrane and annealed at 108°C for 8 minutes to obtain a polymer film.

[0122] Furthermore, the stretched polymer film was placed in liquid ammonia for 4 minutes to cool and modify the polymer film.

[0123] Lead zirconate titanate powder and binder were mixed and stirred evenly at a mass ratio of 95:5, and pre-pressed under 10 MPa pressure to obtain pre-pressed blocks. The pre-pressed blocks were ground, sieved, and then injected into a mold and dry-pressed under 18 MPa pressure to obtain blanks. The lead zirconate titanate powder was obtained by mixing Pb3O4 powder, GeO2 powder, NiO powder, BaCO3 powder, ZrO2 powder, SnO2 powder, and TiO2 powder at a mass ratio of 9:0.2:0.3:1.2:4.8:3.5:1, and the binder was obtained by mixing glycerol, alcohol, and distilled water at a mass ratio of 16:4:80.

[0124] The blank is sintered at high temperature to obtain a piezoelectric ceramic body. The blank is first heated from room temperature to 960°C and held for 0.5 hours, and then heated from the current temperature to 1120°C and held for 3.5 hours to complete the sintering operation.

[0125] The piezoelectric ceramic body is ground into powder, and the resulting powder is sieved through a 2500-mesh sieve. The sieved piezoelectric ceramic powder is then mixed with a viscous solvent to obtain a piezoelectric ceramic powder suspension; wherein the viscous solvent is cyclohexane. The mass percentage of piezoelectric ceramic powder in the suspension is 1.5%.

[0126] A piezoelectric ceramic powder suspension was uniformly coated onto both surfaces of a modified polymer film. The modified polymer film was then placed in an oven and heated to 98°C to allow the viscous solvent to evaporate. The amount of piezoelectric ceramic powder suspension applied to the modified polymer film surface was 120 ml / m². 2 .

[0127] The initial diaphragm obtained in the above steps is placed in a thermal environment of 165°C and a polarization electric field with a fixed field strength direction for polarization. Specifically, the electric field strength of the polarization electric field is 220V / m, and the polarization time is 30 minutes. After polarization is completed, a diaphragm with piezoelectric ceramic coating can be obtained.

[0128] Example 9

[0129] The polymer film was longitudinally stretched at 210°C with a stretch ratio of 6.8; then it was transversely stretched at 170°C with a stretch ratio of 4.

[0130] Specifically, the preparation method of the polymer film includes the following steps: Polytetrafluoroethylene powder, petroleum ether, and KH-550 silane coupling agent (γ-aminopropyltriethoxysilane) are mixed evenly in a reaction vessel at a mass ratio of 10:1.8:0.3, and the mixture is sealed and cured at 45°C for 6.5 hours to obtain a paste. The paste is then flattened and stretched using a ten-stage pressing rod to obtain a polymer sheet. The pressing pressure of the first stage is 5.5 MPa, and the pressing temperature is 62°C; the pressing pressure of the second stage is 5.8 MPa, and the pressing temperature is 64°C; the pressing pressure of the third stage is 6.2 MPa. a. The pressing temperature is 66℃; the pressing pressure of the fourth-stage pressing rod is 6.5MPa and the pressing temperature is 67℃; the pressing pressure of the fifth-stage pressing rod is 6.8MPa and the pressing temperature is 68℃; the pressing pressure of the sixth-stage pressing rod is 7.2MPa and the pressing temperature is 69℃; the pressing pressure of the seventh-stage pressing rod is 7.5MPa and the pressing temperature is 70℃; the pressing pressure of the eighth-stage pressing rod is 8MPa and the pressing temperature is 72℃; the pressing pressure of the ninth-stage pressing rod is 8.8MPa and the pressing temperature is 74℃; the pressing pressure of the tenth-stage pressing rod is 9.5MPa and the pressing temperature is 75℃. The polymer sheet was placed in an oven and heated to 125°C to remove petroleum ether. It was then further subjected to radiation crosslinking treatment in a radiation chamber at an intensity of 12 kGy to obtain a crosslinked polytetrafluoroethylene (PTFE) membrane. A solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] dissolved in chlorobenzene at a concentration of 10 mg / mL was uniformly coated onto the crosslinked PTFE membrane and annealed at 108°C for 8 minutes to obtain a polymer film.

[0131] Furthermore, the stretched polymer film was placed in liquid ammonia for 4 minutes to cool and modify the polymer film.

[0132] Lead zirconate titanate powder and binder were mixed and stirred evenly at a mass ratio of 95:5, and pre-pressed under 10 MPa pressure to obtain pre-pressed blocks. The pre-pressed blocks were ground, sieved, and then injected into a mold and dry-pressed under 18 MPa pressure to obtain blanks. The lead zirconate titanate powder was obtained by mixing Pb3O4 powder, GeO2 powder, NiO powder, BaCO3 powder, ZrO2 powder, SnO2 powder, and TiO2 powder at a mass ratio of 8:0.4:0.6:1.2:5:3.6:1, and the binder was obtained by mixing glycerol, alcohol, and distilled water at a mass ratio of 16:4:80.

[0133] The blank is sintered at high temperature to obtain a piezoelectric ceramic body. The blank is first heated from room temperature to 960°C and held for 0.5 hours, and then heated from the current temperature to 1120°C and held for 3.5 hours to complete the sintering operation.

[0134] The piezoelectric ceramic body is ground into powder, and the resulting powder is sieved through a 2500-mesh sieve. The sieved piezoelectric ceramic powder is then mixed with a viscous solvent to obtain a piezoelectric ceramic powder suspension; wherein the viscous solvent is cyclohexane. The mass percentage of piezoelectric ceramic powder in the suspension is 1.5%.

[0135] A piezoelectric ceramic powder suspension was uniformly coated onto both surfaces of a modified polymer film. The modified polymer film was then placed in an oven and heated to 98°C to allow the viscous solvent to evaporate. The amount of piezoelectric ceramic powder suspension applied to the modified polymer film surface was 120 ml / m². 2 .

[0136] The initial diaphragm obtained in the above steps is placed in a thermal environment of 165°C and a polarization electric field with a fixed field strength direction for polarization. Specifically, the electric field strength of the polarization electric field is 220V / m, and the polarization time is 30 minutes. After polarization is completed, a diaphragm with piezoelectric ceramic coating can be obtained.

[0137] Comparative Example 1

[0138] Alumina powder and binder were mixed and stirred evenly at a mass ratio of 95:5, and pre-pressed at 10 MPa to obtain pre-pressed blocks. The pre-pressed blocks were then ground, sieved, and injected into a mold, where they were dry-pressed at 18 MPa to obtain blanks. The binder was prepared by mixing glycerin, alcohol, and distilled water at a mass ratio of 16:4:80. The blanks were sintered at high temperature and then ground. The resulting alumina solid powder was sieved through a 2500-mesh sieve. The sieved alumina solid powder was mixed with a viscous solvent to obtain an alumina solid powder suspension.

[0139] The poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] film was longitudinally stretched at 210°C with a longitudinal stretching ratio of 6.8; then it was transversely stretched at 170°C with a stretching ratio of 4.

[0140] Alumina solid powder suspension was uniformly coated on both surfaces of the stretched poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] membrane. The poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] membrane was then placed in an oven and heated to evaporate the viscous solvent, thus obtaining the initial diaphragm.

[0141] The initial diaphragm obtained in the above steps is placed in a thermal environment of 165°C and a polarization electric field with a fixed field strength direction for polarization. Specifically, the electric field strength of the polarization electric field is 220V / m, and the polarization time is 30 minutes, to obtain an alumina diaphragm.

[0142] Comparative Example 2

[0143] Alumina powder and binder were mixed and stirred evenly at a mass ratio of 95:5, and pre-pressed at 10 MPa to obtain pre-pressed blocks. The pre-pressed blocks were then ground, sieved, and injected into a mold, where they were dry-pressed at 18 MPa to obtain blanks. The binder was prepared by mixing glycerin, alcohol, and distilled water at a mass ratio of 16:4:80. The blanks were then sintered at high temperature and ground. The resulting alumina solid powder was sieved through a 2500-mesh sieve.

[0144] Polytetrafluoroethylene powder, petroleum ether, and alumina solid powder were mixed evenly in a reactor at a mass ratio of 10:1.8:0.3. The mixture was then sealed and cured at 45°C for 6.5 hours to obtain a paste. This paste was then flattened and stretched using a ten-stage pressing rod to obtain polymer sheets. The first stage pressing rod had a pressing pressure of 5.5 MPa and a pressing temperature of 62°C; the second stage pressing rod had a pressing pressure of 5.8 MPa and a pressing temperature of 64°C; the third stage pressing rod had a pressing pressure of 6.2 MPa and a pressing temperature of 66°C; and the fourth stage pressing rod had a pressing temperature of... The pressure of the first stage was 6.5 MPa, and the pressing temperature was 67°C; the fifth stage pressure was 6.8 MPa, and the pressing temperature was 68°C; the sixth stage pressure was 7.2 MPa, and the pressing temperature was 69°C; the seventh stage pressure was 7.5 MPa, and the pressing temperature was 70°C; the eighth stage pressure was 8 MPa, and the pressing temperature was 72°C; the ninth stage pressure was 8.8 MPa, and the pressing temperature was 74°C; and the tenth stage pressure was 9.5 MPa, and the pressing temperature was 75°C. The polymer sheets were placed in an oven and the heating temperature was set to 125°C to dry and remove petroleum ether, thus obtaining the initial diaphragm.

[0145] The initial diaphragm was longitudinally stretched at 210°C with a stretching ratio of 6.8; then it was transversely stretched at 170°C with a stretching ratio of 4.

[0146] The initial diaphragm obtained in the above steps is placed in a thermal environment of 165°C and a polarization electric field with a fixed field strength direction for polarization. Specifically, the electric field strength of the polarization electric field is 220V / m, and the polarization time is 30 minutes, to obtain an alumina diaphragm.

[0147] Comparative Example 3

[0148] Alumina powder and binder were mixed and stirred evenly at a mass ratio of 95:5, and pre-pressed at 10 MPa to obtain pre-pressed blocks. The pre-pressed blocks were then ground, sieved, and injected into a mold, where they were dry-pressed at 18 MPa to obtain blanks. The binder was prepared by mixing glycerin, alcohol, and distilled water at a mass ratio of 16:4:80. The blanks were sintered at high temperature and then ground. The resulting alumina solid powder was sieved through a 2500-mesh sieve. The sieved alumina solid powder was mixed with a viscous solvent to obtain an alumina solid powder suspension.

[0149] The polytetrafluoroethylene film was longitudinally stretched at 210°C with a longitudinal stretching ratio of 6.8; then it was transversely stretched at 170°C with a stretching ratio of 4.

[0150] Specifically, the preparation method of polytetrafluoroethylene (PTFE) film includes the following steps: PTFE powder is mixed evenly with petroleum ether and KH-550 silane coupling agent (γ-aminopropyltriethoxysilane) at a mass ratio of 10:1.8:0.3 in a reaction vessel, and then cured in a sealed container at 45°C for 6.5 hours to obtain a paste. The paste is then flattened and stretched using a ten-stage pressing rod to obtain a polymer sheet. The pressing pressure of the first stage is 5.5 MPa, and the pressing temperature is 62°C; the pressing pressure of the second stage is 5.8 MPa, and the pressing temperature is 64°C; the pressing pressure of the third stage is 6.2 MPa. The pressing pressure of the fourth-stage press bar is 6.5 MPa, and the pressing temperature is 67°C; the pressing pressure of the fifth-stage press bar is 6.8 MPa, and the pressing temperature is 68°C; the pressing pressure of the sixth-stage press bar is 7.2 MPa, and the pressing temperature is 69°C; the pressing pressure of the seventh-stage press bar is 7.5 MPa, and the pressing temperature is 70°C; the pressing pressure of the eighth-stage press bar is 8 MPa, and the pressing temperature is 72°C; the pressing pressure of the ninth-stage press bar is 8.8 MPa, and the pressing temperature is 74°C; the pressing pressure of the tenth-stage press bar is 9.5 MPa, and the pressing temperature is 75°C. The polymer sheet is placed in an oven and the heating temperature is set to 125°C to dry and remove petroleum ether, thus obtaining a polytetrafluoroethylene (PTFE) film.

[0151] Alumina solid powder suspension is uniformly coated on both surfaces of the stretched polytetrafluoroethylene membrane. The polytetrafluoroethylene membrane is then placed in an oven and heated to evaporate the viscous solvent, thus obtaining the initial diaphragm.

[0152] The initial diaphragm obtained in the above steps is placed in a thermal environment of 165°C and a polarization electric field with a fixed field strength direction for polarization. Specifically, the electric field strength of the polarization electric field is 220V / m, and the polarization time is 30 minutes, to obtain an alumina diaphragm.

[0153] Test Example 1

[0154] Conduction efficiency test: The ion conduction efficiency of the separators obtained in Examples 4-9 and Comparative Examples 1-3 of the present invention was tested. A positive electrode material layer and a negative electrode material layer were disposed on both sides of the separators in the above examples and comparative examples. The positive electrode material layer was rich in lithium-ion salt, and the negative electrode material layer was rich in lithium-silicon composite active material. A silver metal sheet was disposed on the outer side of the positive electrode material layer as a positive electrode contact plate, and a silver metal sheet was disposed on the outer side of the negative electrode material layer as a negative electrode contact plate, thereby forming a rechargeable battery assembly. A rated voltage of 5V was applied to the two contact plates, and the current between the positive and negative electrodes was tested to perform a conduction efficiency test on the separator. The results are shown in Table 1.

[0155] Table 1

[0156] Serial number Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Current (mA) 453 462 450 475 481 464 Serial number Comparative Example 1 Comparative Example 2 Comparative Example 3 Current (mA) 421 407 434

[0157] Through comparative testing, it was found that by stretching the polymer film and then immersing it in liquid ammonia for modification, the pores in the polymer film can be compressed and shaped, thereby maintaining the pore size and improving the ion conduction efficiency.

[0158] Test Example 2

[0159] Battery capacity testing: The separators obtained in Examples 1-9 and Comparative Examples 1-3 of this invention were subjected to battery capacity testing. Positive and negative electrode material layers were disposed on both sides of the separators in the above examples and comparative examples. A silver metal sheet was disposed on the outer side of the positive electrode material layer as a positive electrode contact plate, and a silver metal sheet was disposed on the outer side of the negative electrode material layer as a negative electrode contact plate, thereby forming a rechargeable battery assembly. A pulsed DC current with a rated voltage of 5V was applied to the two contact plates to repeatedly charge the rechargeable battery assembly. The pulse frequency was 40kHz, and the number of charging cycles was 500. The ratio of the current battery capacity to the initial battery capacity of the rechargeable battery assembly after 500 charging cycles was tested. The results are shown in Table 2.

[0160] Table 2

[0161] Serial number Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Capacity ratio 0.937 0.933 0.946 0.956 0.952 0.957 Serial number Example 7 Example 8 Example 9 Comparative Example 1 Comparative Example 2 Comparative Example 3 Capacity ratio 0.946 0.942 0.950 0.733 0.695 0.726

[0162] Through comparative testing, it was found that by adding piezoelectric ceramic particles to the surface of the polymer film, when a pulsed DC current is applied for charging, the piezoelectric ceramic particles can vibrate and effectively prevent the formation of dendrites, thereby significantly reducing the capacity loss of the rechargeable battery after repeated charging and improving the utilization efficiency of the rechargeable battery.

[0163] The piezoelectric ceramic-coated separator and its manufacturing method provided in this embodiment of the invention involve stretching a polymer film and immersing it in liquid ammonia for cooling to obtain a modified polymer film. Piezoelectric ceramic powder is mixed with a binder and pre-pressed to obtain a pre-pressed block. This block is then ground, sieved, and injected into a mold for dry pressing to obtain a blank. The blank is sintered at high temperature to obtain a piezoelectric ceramic body, which is then ground, sieved, and mixed with a viscous solvent to form a piezoelectric ceramic powder suspension. The suspension is uniformly coated onto the surface of the modified polymer film and heated. The resulting separator is then placed in an environment of 140-180°C and under a polarized electric field with a fixed field strength direction for polarization to obtain a separator with piezoelectric ceramic coating. The above method involves stretching and cooling the polymer film to form through-holes. Piezoelectric ceramic particles are then laid on the surface of the polymer film to obtain a separator with piezoelectric ceramic coating. A DC pulse current is applied to drive the piezoelectric ceramic particles on the separator to vibrate, causing the separator to mechanically expand and contract, thereby breaking up metal ion crystals on the separator through mechanical force. This effectively prevents the formation of crystal nuclei on the inner side of the battery electrode.

[0164] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for manufacturing a diaphragm coated with piezoelectric ceramic, characterized in that, The method includes: The polymer film is longitudinally stretched at 165-235℃ with a longitudinal stretching ratio of 4-9; then it is transversely stretched at 135-185℃ with a stretching ratio of 2.5-5. The stretched polymer film is immersed in liquid ammonia for 2-5 minutes to cool it and obtain a modified polymer film. Piezoelectric ceramic powder and binder are mixed and stirred evenly at a mass ratio of (92-96):(2-5), and pre-pressed under a pressure of 6-15MPa to obtain pre-pressed blocks. The pre-pressed blocks are ground, sieved, and then injected into a mold and dry-pressed under a pressure of 8-22MPa to obtain blanks. The blank is sintered at 900-1200℃ for 2-5 hours to obtain a piezoelectric ceramic body; The piezoelectric ceramic body is ground and then sieved. The sieved piezoelectric ceramic powder is mixed with a viscous solvent to form a piezoelectric ceramic powder suspension. The piezoelectric ceramic powder suspension is uniformly coated on the surface of the modified polymer film, and the modified polymer film is placed in an oven and the heating temperature is set to 95-110℃ to evaporate the viscous solvent, thus obtaining the initial diaphragm. The initial diaphragm was polarized in an environment of 140-180℃ and under a polarized electric field with a fixed field strength direction to obtain a diaphragm with piezoelectric ceramic coating. The piezoelectric ceramic powder is obtained by mixing Pb3O4 powder, GeO2 powder, NiO powder, BaCO3 powder, ZrO2 powder, SnO2 powder and TiO2 powder in a mass ratio of (7.5-9.5):(0.2-0.5):(0.3-0.8):(0.6-1.8):(4.6-5):(3.2-3.8):(0.6-1.3); the viscous solvent is one or more combinations of isopropanol, cyclohexane and methylcyclohexanol. The piezoelectric ceramic powder suspension contains 0.8-2% piezoelectric ceramic powder by mass; the coating amount of the piezoelectric ceramic powder suspension on the modified polymer film surface is 45-200 ml / m. 2 .

2. The method for manufacturing a diaphragm coated with piezoelectric ceramic according to claim 1, characterized in that, The method for preparing the polymer film includes: Polytetrafluoroethylene powder, petroleum ether, and silane coupling agent are mixed evenly in a reaction vessel at a mass ratio of 10:2.2:(0.2-0.5), and then sealed and cured at 40-50℃ for 6-8 hours to obtain a paste. The above paste is flattened and stretched using a pressure bar under a pressure of 5-9.5 MPa to form a polymer sheet; the flattening and stretching temperature is 62-75℃. The polymer sheet was placed in an oven and the heating temperature was set to 120-130℃ to dry and remove the petroleum ether. The membrane is further fed into a radiation chamber for radiation cross-linking treatment to obtain a cross-linked polytetrafluoroethylene membrane. A solution of poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] dissolved in chlorobenzene at a concentration of 6-25 mg / mL was uniformly coated onto the cross-linked polytetrafluoroethylene membrane and then annealed to obtain a polymer film.

3. The method for manufacturing a diaphragm coated with piezoelectric ceramic according to claim 1, characterized in that, The step of grinding the piezoelectric ceramic body and then sieving it includes: sieving the ground piezoelectric ceramic powder through a 1200-4000 mesh sieve.

4. The method for manufacturing a diaphragm coated with piezoelectric ceramic according to claim 1, characterized in that, The electric field strength of the polarized electric field is 160-350 V / m.

5. The method for manufacturing a diaphragm coated with piezoelectric ceramic according to claim 4, characterized in that, The polarization duration is 20-45 minutes.

6. A diaphragm coated with piezoelectric ceramic, characterized in that, The diaphragm is prepared by the manufacturing method of the diaphragm with piezoelectric ceramic coating as described in any one of claims 1-5, wherein the diaphragm comprises a polymer film and piezoelectric ceramic particles laid on the surface of the polymer film. The polymer film is composed of a cross-linked polytetrafluoroethylene film and a poly[bis(4-phenyl)(2,4,6-trimethylphenyl)amine] film laminated together; the piezoelectric ceramic particles are laid on both sides of the polymer film. The polymer film has uniformly distributed through holes, the thickness of the polymer film is 20-140 μm, and the pore size of the through holes is 20-50 μm. The piezoelectric ceramic particles are lead zirconate titanate ceramic particles, and the particle size of the piezoelectric ceramic particles is 0.5-25μm.

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