An ultrahigh inverse piezoelectric performance anti-reduction potassium sodium niobate-based lead-free piezoelectric ceramic, a preparation method and application thereof

Abstract

The application relates to the technical field of piezoelectric ceramic devices, and particularly discloses a super-high inverse piezoelectric performance anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic with a chemical formula of (1-x)(Na 1‑y K y ) z Nb 1‑h Ta h O3-xAZr t O3+i% M+k% N, wherein x, y, z, h, t, i and k represent molar fractions, 0.04<=x<0.08, 0.45

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of piezoelectric ceramic devices, and particularly relates to a super-high inverse piezoelectric performance anti-reduction potassium-sodium niobate-based lead-free piezoelectric ceramic and a preparation method and application thereof. BACKGROUND

[0002] As an important functional material for mutual conversion between mechanical energy and electrical energy, piezoelectric materials are widely used in ultrasonic imaging, buzzer, sonar, micro-driver and other fields. The inverse piezoelectric performance of piezoelectric ceramics is an important indicator of piezoelectric drivers. At present, the material system dominating the piezoelectric device market is mainly lead-based material. However, due to the production and abandonment of lead-based materials, it will cause serious toxic hazards to the human body and the environment. Many countries or regions have introduced laws and regulations to restrict the application of lead-containing materials in electronic and electrical equipment. The restriction of lead-containing piezoelectric devices will have a huge impact on China's electronic information field. In order to achieve the sustainable development of China's electronic information industry, the research of green and environmentally friendly lead-free piezoelectric materials is very urgent.

[0003] Among many lead-free piezoelectric systems, potassium-sodium niobate (KNN)-based materials have attracted much attention due to their high Curie temperature, large electromechanical coupling coefficient, and environmental friendly characteristics. After years of development, the piezoelectric performance of KNN-based lead-free piezoelectric ceramics has been significantly improved, and the piezoelectric performance of some KNN-based materials has been better than that of lead-based materials, which indicates that KNN-based lead-free piezoelectric ceramics have the potential to replace lead-based ceramics for commercial applications.

[0004] Although KNN-based piezoelectric materials have shown great commercial potential, the comprehensive performance still cannot fully surpass the lead-containing system. To achieve the goal of replacing lead-based materials with KNN-based ceramics, it is necessary to further improve the piezoelectric performance of KNN-based ceramics and realize the multi-layer design of devices. Multi-layer design is also listed as a major trend in the development of future piezoelectric devices. The inner electrode of existing multi-layer devices is mainly silver-palladium electrode. The high price of silver-palladium electrode will inevitably lead to an increase in the cost of piezoelectric multi-layer devices. The promotion of nickel electrode piezoelectric multi-layer devices has obvious price advantage and great scientific research value. KNN-based materials have obvious comprehensive advantages and great commercial value in matching with nickel electrode co-firing and piezoelectric performance regulation.

[0005] However, the oxidation resistance of nickel electrode is poor, and strong reducing atmosphere is needed to protect the co-firing process of nickel electrode and KNN-based materials. Strong reducing atmosphere will induce more oxygen vacancies and free electrons in the ceramic, reduce the band gap of KNN-based ceramic, and deteriorate the room temperature and high temperature insulation performance of the ceramic. Low insulation performance will lead to insufficient polarization of the ceramic and poor piezoelectric performance. Therefore, the research on high-performance anti-reduction KNN-based ceramic materials is not only of great significance but also of great difficulty.

[0006] In addition, since the sintering temperature of KNN-based piezoelectric ceramics is very high (generally greater than 1100 DEG C), a large amount of K and Na volatilizes during the sintering process of the system, a large amount of A-site defects and oxygen vacancies are generated, and many researchers believe that the volatilization of K and Na is the cause of the decrease of the inverse piezoelectric performance of KNN-based piezoelectric ceramics. However, the inventors of the present application found in the research that the regulation of phase structure heterogeneity by inducing appropriate A-site defects according to the component can significantly improve the piezoelectric performance of the reduction-resistant KNN-based piezoelectric ceramics, and the present application aims to provide a reduction-resistant potassium sodium niobate-based lead-free piezoelectric ceramic with ultra-high inverse piezoelectric performance. SUMMARY

[0007] In view of the above shortcomings, the present application provides a reduction-resistant potassium sodium niobate-based lead-free piezoelectric ceramic with ultra-high inverse piezoelectric performance and a preparation method thereof. The inverse piezoelectric performance and temperature stability of the potassium sodium niobate-based lead-free piezoelectric ceramic are improved by ceramic component design, and the specific technical solutions are as follows:

[0008] A reduction-resistant potassium sodium niobate-based lead-free piezoelectric ceramic with ultra-high inverse piezoelectric performance has a chemical formula of: (1-x)(Na 1-y K y ) z Nb 1-h Ta h O3-xAZr t O3+i%M+k%N, wherein x, y, z, h, t, i and k represent molar fractions, 0.04<=x<0.08, 0.45<y<0.52, 0.95<=z<1, 0<=h<=0.07, 1<=t<=2, 8<=i<=15, 0<=k<=1; M represents a manganese compound, the manganese compound is MnO, Mn2O3, MnCO3 or MnO2, A is Ba, Sr or Ca, and N is Li2CO3.

[0009] Preferably, the reduction-resistant potassium sodium niobate-based lead-free piezoelectric ceramic with ultra-high inverse piezoelectric performance has a chemical formula of: (1-x)(Na 1-y K y ) z Nb 1-h Ta h O3-xAZr t O3+i%M+k%N, wherein x, y, z, h, t, i and k represent molar fractions, 0.04<=x<0.08, 0.45<y<0.52, 0.95<=z<1, 0<=h<=0.07, 1<=t<=2, 8<=i<=15, 0<=k<=1; M represents a manganese compound, the manganese compound is MnO, Mn2O3, MnCO3 or MnO2, A is Ba, Sr or Ca, and N is Li2CO3.

[0010] Preferably, the above-mentioned super-high inverse piezoelectric performance anti-reduction potassium sodium niobate-based lead-free piezoelectric ceramic has a chemical formula of: 0.94(Na 0.5 K 0.5 ) 0.98 Nb 0.96 Ta 0.04 O3-0.06BaZr 1.5 O3+8.5%MnO+0.1mol%Li2CO3.

[0011] In another aspect, the present application also provides a preparation method of the above-mentioned super-high inverse piezoelectric performance anti-reduction potassium sodium niobate-based lead-free piezoelectric ceramic, comprising the following steps:

[0012] (1) weighing raw materials Na2CO3, K2CO3, Nb2O5, ZrO2, ACO3, Ta2O5, Li2CO3 and manganese compound according to stoichiometric ratio in the chemical formula, and then sequentially performing ball milling, drying and calcination to obtain a ceramic material;

[0013] (2) sequentially performing ball milling, granulation, compression molding, degassing, sintering and re-oxidation in a reducing atmosphere to obtain the super-high inverse piezoelectric performance anti-reduction potassium sodium niobate-based lead-free piezoelectric ceramic.

[0014] Preferably, in the above-mentioned preparation method of the super-high inverse piezoelectric performance anti-reduction potassium sodium niobate-based lead-free piezoelectric ceramic, in the step (1), the ball milling process parameters are: the ball milling medium is anhydrous ethanol, the ball milling rotation speed is 300-400 r / min, and the time is 20-30 h; and the calcination process parameters are: the temperature is 800-950 ℃, and the time is 2-6 h.

[0015] Preferably, in the above-mentioned preparation method of the super-high inverse piezoelectric performance anti-reduction potassium sodium niobate-based lead-free piezoelectric ceramic, in the step (2), the sintering process parameters are: the heating rate is 4-6 ℃ / min, the sintering temperature is 1050-1090 ℃, the holding time is 2-4 h, the reducing atmosphere is composed of 0.6-1.5% (by volume fraction) H2 and 98.5-99.4% N2, the oxygen partial pressure P O2 is 1×10 -10 -1×10 -13 atm.

[0016] Preferably, in the above-mentioned preparation method of the super-high inverse piezoelectric performance anti-reduction potassium sodium niobate-based lead-free piezoelectric ceramic, in the step (2), the re-oxidation is: after the sintering holding is completed, the temperature is reduced to 800-900 ℃ at a cooling rate of 4-7 ℃ / min, and by adjusting the ratio of N2 and H2, the oxygen partial pressure of the reducing atmosphere is controlled to be 10 -6 -10 -9atm, and the atmosphere is maintained for 4 to 10 hours, and after the end, the atmosphere is maintained to be reduced to room temperature.

[0017] Preferably, the preparation method of the super-high inverse piezoelectric performance anti-reduction potassium sodium niobate-based lead-free piezoelectric ceramic further comprises: after sintering and re-oxidation, gold electrode and polarization are performed.

[0018] The gold electrode is performed by a magnetron sputtering method.

[0019] The polarization is performed in silicone oil, and the polarization conditions are: a polarization temperature is 80 to 130 DEG C, a polarization electric field is 3 to 4 kV / mm, and a polarization time is 20 to 30 min.

[0020] In another aspect, the application also provides the application of the super-high inverse piezoelectric performance anti-reduction potassium sodium niobate-based lead-free piezoelectric ceramic in the preparation of a micro piezoelectric driver.

[0021] Preferably, in the application, the preparation of the micro piezoelectric driver comprises co-firing the super-high inverse piezoelectric performance anti-reduction potassium sodium niobate-based lead-free piezoelectric ceramic and a Ni electrode.

[0022] Compared with the prior art, the application has the following beneficial effects:

[0023] The super-high inverse piezoelectric performance anti-reduction potassium sodium niobate-based lead-free piezoelectric ceramic of the application can drive out a super-high inverse piezoelectric coefficient d * 33 of 1730 pm / V (extremely low driving electric field E = 9.0 kV / cm) by appropriately reducing the amount of K and Na to induce an appropriate amount of A-site defects to regulate the phase structure heterogeneity. * 33 Meanwhile, the piezoelectric potassium sodium niobate-based lead-free piezoelectric ceramic has high temperature stability, high resistivity, good anti-reduction properties, and excellent comprehensive performance, which is conducive to the application in the preparation of micro multi-layer devices. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without any creative labor on the basis of these drawings.

[0025] Figure 1 The single-pole strain and electric field relationship diagram of the potassium sodium niobate-based lead-free piezoelectric ceramic prepared for the embodiment 1 of the application. DETAILED DESCRIPTION

[0026] The specific embodiments of the present application are described in detail below, but the scope of protection of the present application is not limited by the specific embodiments. Unless otherwise defined, all the professional terms used below have the same meaning as generally understood by those skilled in the art. The professional terms used herein are only for the purpose of describing the specific embodiments and are not intended to limit the scope of protection of the present application. Unless otherwise specified, the various raw materials, reagents, instruments and equipment used in the present application can be purchased on the market or can be prepared by existing methods.

[0027] Example 1

[0028] An ultra-high inverse piezoelectric performance anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic has a chemical formula of:

[0029] 0.94(Na 0.5 K 0.5 ) 0.98 Nb 0.96 Ta 0.04 O3-0.06BaZr 1.5 O3+8.5mol%MnO+0.1mol%Li2CO3.

[0030] The present embodiment also provides a preparation method of an ultra-high inverse piezoelectric performance anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic, comprising the following steps:

[0031] (1) The raw materials Na2CO3, K2CO3, Nb2O5, ZrO2, BaCO3, Ta2O5, Li2CO3 and MnO are weighed according to the stoichiometric ratio in the chemical formula, and the weighed raw materials are put into a ball mill tank, anhydrous ethanol is added, the amount of anhydrous ethanol is 15 times the weight of the raw materials, ball milling is carried out at a speed of 350 r / min for 24 h, the powder is dried by rotary evaporation (temperature is 60℃, time is 1h), then calcination is carried out at 850℃ for 5h, and the ceramic material is obtained;

[0032] (2) The ceramic material obtained in step (1) is ball milled again, anhydrous ethanol is used as the ball milling medium, the amount of anhydrous ethanol is 15 times the weight of the ceramic material, ball milling is carried out at a speed of 300 r / min for 24 h; 5% of polyvinyl butyral binder is added to the ceramic material for granulation, and then the ceramic material is pressed into a shape under the condition of 100 MPa, and then the glue is removed by heating to 600℃ at a heating rate of 3℃ / min and keeping for 2h;

[0033] Then sintering is carried out in an atmosphere furnace, the sintering process parameters are: the heating rate is 5℃ / min, the sintering temperature is 1080℃, the holding time is 3h, the reducing atmosphere is composed of 1% H2 and 99% N2 by volume fraction, the oxygen partial pressure P O2 is controlled at 1×10 -10 ~1×10-12 atm; after sintering, the temperature is decreased to 850℃ at a rate of 5℃ / min, and the oxygen partial pressure of the reducing atmosphere is controlled to be 10 -6 ~10 -7 atm by adjusting the ratio of N2 and H2, and the re-oxidation is carried out for 5h, and then the temperature is decreased to room temperature under the same atmosphere, to obtain a ceramic sheet;

[0034] (3) The ceramic sheet obtained in step (2) is polished, and a gold electrode with a thickness of ~3μm is formed by magnetron sputtering, and then the polarization is carried out in silicon oil at 100℃, the polarization electric field is 3kV / mm, and the polarization time is 30min, to obtain a super-high inverse piezoelectric performance anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic.

[0035] Example 2

[0036] A super-high inverse piezoelectric performance anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic has a chemical formula of:

[0037] 0.935(Na 0.5 K 0.5 ) 0.99 Nb 0.96 Ta 0.04 O3-0.065BaZr 1.4 O3+9mol%MnO+0.1mol%Li2CO3.

[0038] The preparation method of the super-high inverse piezoelectric performance anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic of the present example is the same as that of Example 1, except that the stoichiometric ratio of the raw materials is different.

[0039] Example 3

[0040] A super-high inverse piezoelectric performance anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic has a chemical formula of:

[0041] 0.94(Na 0.5 K 0.5 ) 0.98 Nb 0.97 Ta 0.03 O3-0.06BaZr 1.4 O3+8mol%Mn2O3+0.1mol%Li2CO3.

[0042] The preparation method of the super-high inverse piezoelectric performance anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic of the present example is the same as that of Example 1, except that Mn2O3 is used to replace MnO in the raw materials, and the stoichiometric ratio of the raw materials is different.

[0043] Example 4

[0044] A super-high inverse piezoelectric performance anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic has a chemical formula of:

[0045] 0.955(Na 0.53 K 0.47 ) 0.99 Nb 0.96 Ta 0.04 O3-0.045SrZr 1.4 O3+8mol%MnO2+0.3mol%Li2CO3.

[0046] The preparation method of the super-high inverse piezoelectric performance anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic of the embodiment is the same as that of embodiment 1, except that SrCO3 is used to replace BaCO3 and MnO2 is used to replace MnO in the raw materials, and the stoichiometric ratio of the raw materials is different.

[0047] Embodiment 5

[0048] A super-high inverse piezoelectric performance anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic has a chemical formula of:

[0049] 0.94(Na 0.51 K 0.49 ) 0.97 Nb 0.98 Ta 0.02 O3-0.06BaZr 1.5 O3+8mol%MnCO3.

[0050] The preparation method of the super-high inverse piezoelectric performance anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic of the embodiment is the same as that of embodiment 1, except that no Li2CO3 is added in the raw materials, MnCO3 is used to replace MnO, and the stoichiometric ratio of the raw materials is different.

[0051] Embodiment 6

[0052] A super-high inverse piezoelectric performance anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic has a chemical formula of:

[0053] 0.94(Na 0.52 K 0.48 ) 0.98 Nb 0.97 Ta 0.03 O3-0.06CaZr 1.2 O3+8mol%Mn3O4+0.3mol%Li2CO3.

[0054] The preparation method of the super-high inverse piezoelectric performance anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic of the embodiment is the same as that of embodiment 1, except that CaCO3 is used to replace BaCO3 and Mn3O4 is used to replace MnO in the raw materials, and the stoichiometric ratio of the raw materials is different.

[0055] Comparative Example 1

[0056] A lead-free piezoelectric ceramic based on sodium potassium niobate, with the chemical formula:

[0057] 0.94Na 0.5 K 0.5 Nb 0.96 Ta 0.04 O3-0.06BaZr 1.5 O3+8.5mol%MnO+0.1mol%Li2CO3.

[0058] The preparation method of the potassium sodium niobate-based lead-free piezoelectric ceramic in this comparative example is the same as that in Example 1, except that the stoichiometric ratio of the raw materials is different.

[0059] Comparative Example 2

[0060] A lead-free piezoelectric ceramic based on sodium potassium niobate, with the chemical formula:

[0061] 0.94(Na 0.5 K 0.5 ) 0.94 Nb 0.96 Ta 0.04 O3-0.06BaZr 1.5 O3+8.5mol%MnO+0.1mol%Li2CO3.

[0062] The preparation method of the potassium sodium niobate-based lead-free piezoelectric ceramic in this comparative example is the same as that in Example 1, except that the stoichiometric ratio of the raw materials is different. This component material is semiconductor with very low electrical resistance, making it impossible to test its piezoelectric strain properties.

[0063] The performance of the sodium potassium niobate-based lead-free piezoelectric ceramics prepared in Examples 1-6 and Comparative Examples 1-2 was tested after being placed at room temperature for 24 hours.

[0064] Figure 1 The inverse piezoelectric coefficient d of the sodium potassium niobate-based lead-free piezoelectric ceramic of Example 1 is shown. * 33 The graph shows the relationship between the inverse piezoelectric coefficient and the electric field. As can be seen from the graph, the electric field corresponding to the maximum inverse piezoelectric coefficient (1730 pm / V) produced by the potassium sodium niobate-based lead-free piezoelectric ceramic in Example 1 is 9.0 kV / cm, and the inverse piezoelectric coefficient d... * 33 It exhibits excellent performance with a very low driving electric field, making it a promising candidate for future applications in micro multilayer devices.

[0065] The performance data of the sodium potassium niobate-based lead-free piezoelectric ceramics in Examples 1-6 and Comparative Examples 1-2 are shown in Table 1. In Comparative Example 2, the material is semiconductive with low electrical resistance, making it impossible to test its piezoelectric strain performance. Table 1 shows that the inverse piezoelectric coefficient d of the sodium potassium niobate-based lead-free piezoelectric ceramics prepared in the embodiments of this invention is... * 33Excellent, high temperature stability, very low driving electric field, high resistivity, good resistance to reduction, excellent comprehensive performance, great potential in micro multi-layer device applications.

[0066] Table 1 Properties of potassium sodium niobate-based lead-free piezoelectric ceramics

[0067]

[0068] The foregoing description of specific exemplary embodiments of the application has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the application to the precise form disclosed, and various modifications and variations are possible in light of the above teachings. It is intended that the application encompass all such modifications and variations as fall within the scope of the claims and their equivalents. The exemplary embodiments were chosen and described in order to explain the principles of the application and its practical application to thereby enable others skilled in the art to best utilize the application and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the scope of the application be defined by the claims and their equivalents.

Claims

1. An anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic with ultrahigh inverse piezoelectric properties, characterized by, Chemical formula: (1-x)(Na 1-y K y ) z Nb 1-h Ta h O3- x AZr t O3+ i %M+ k %N, wherein x, y, z, h, t, i and k represent molar fractions, 0.04≤x<0.08, 0.45<y<0.52, 0.95≤z<1, 0≤h≤0.07, 1≤t≤2, 8≤i≤15, 0≤k≤1; M represents a manganese compound, the manganese compound being MnO, Mn2O3, MnCO3 or MnO2, A being Ba, Sr or Ca, N being Li2CO3; the preparation method of the super-high inverse piezoelectric performance reduction-resistant sodium potassium niobate-based lead-free piezoelectric ceramic comprises the following steps: (1) The raw materials Na2CO3, K2CO3, Nb2O5, ZrO2, ACO3, Ta2O5, Li2CO3 and manganese compounds are weighed according to the stoichiometric ratio in the chemical formula, and then ball milling, drying and calcination are sequentially performed to obtain the porcelain material; (2) The porcelain material obtained in step (1) is sequentially subjected to ball milling, granulation, compression molding, degassing, sintering in a reducing atmosphere and re-oxidation to obtain the super-high inverse piezoelectric performance reduction-resistant sodium potassium niobate-based lead-free piezoelectric ceramic.

2. The anti-reducing potassium-sodium niobate-based lead-free piezoelectric ceramics with ultrahigh inverse piezoelectric property according to claim 1, characterized in that, having the chemical formula: (1-x)(Na 1-y K y ) z Nb 1-h Ta h O3- x AZr t O3+ i %M+ k %N, wherein x, y, z, h, t, i and k represent molar fractions, 0.04≤x≤0.065, 0.46≤y≤0.5, 0.97≤z≤0.995, 0.01≤h≤0.04, 1.2≤t≤1.6, 8≤i≤10, 0≤k≤0.8; M represents a manganese compound, the manganese compound being MnO, Mn2O3, MnCO3 or MnO2, A is Ba, Sr or Ca, and N is Li2CO3.

3. The anti-reducing potassium-sodium niobate-based lead-free piezoelectric ceramics with ultrahigh inverse piezoelectric property according to claim 2, characterized in that, Chemical formula: 0.94(Na 0.5 K 0.5 ) 0.98 Nb 0.96 Ta 0.04 O3-0.06BaZr 1.5 O3+8.5%MnO+0.1%Li2CO3.

4. A method for preparing the anti-reduction sodium potassium niobate-based lead-free piezoelectric ceramic having ultra-high inverse piezoelectric properties according to any one of claims 1 to 3, characterized in that, The method comprises the following steps: (1) The raw materials Na2CO3, K2CO3, Nb2O5, ZrO2, ACO3, Ta2O5, Li2CO3 and manganese compounds are weighed according to the stoichiometric ratio in the chemical formula, and then ball milling, drying and calcination are sequentially performed to obtain the porcelain material; (2) The porcelain material obtained in step (1) is sequentially subjected to ball milling, granulation, compression molding, degassing, sintering in a reducing atmosphere and re-oxidation to obtain the super-high inverse piezoelectric performance reduction-resistant sodium potassium niobate-based lead-free piezoelectric ceramic.

5. The method of claim 4, wherein the method is characterized by: In step (1), the ball milling process parameters are as follows: the ball milling medium is anhydrous ethanol, the ball milling speed is 300-400 r / min, and the time is 20-30 h; the calcination process parameters are as follows: the temperature is 800-950 ℃, and the time is 2-6 h.

6. The method of claim 4, wherein the method is characterized by: In the step (2), the sintering process parameters are as follows: the temperature rising rate is 4-6 ℃ / min, the sintering temperature is 1050-1090 ℃, the holding time is 2-4 h, the reducing atmosphere is composed of H2 with a volume fraction of 0.6-1.5% and N2 with a volume fraction of 98.5-99.4%, and the oxygen partial pressure P O2 is 1×10 -10 -1×10 -13 atm.

7. The method of claim 4, wherein the method is characterized by: In step (2), re-oxidation is performed as follows: after sintering and heat preservation, the temperature is reduced to 800-900°C at a rate of 4-7°C / min, and the oxygen partial pressure of the reducing atmosphere is controlled to 10 -6 ~10 -9 atm by adjusting the ratio of N2 and H2, and the temperature is maintained for 4-10 h, after which the temperature is reduced to room temperature under the same atmosphere.

8. The method of claim 4, wherein the method is characterized by: Further comprising: After sintering and re-oxidation, gold electrode and polarization are performed; The gold electrode is performed by a magnetron sputtering method; The polarization is performed in silicone oil, and the polarization conditions are as follows: the polarization temperature is 80-130 ℃, the polarization electric field is 3-4 kV / mm, and the polarization time is 20-30 min.

9. Use of the super-high inverse piezoelectric performance reduction-resistant sodium potassium niobate-based lead-free piezoelectric ceramic according to any one of claims 1-3 in the preparation of a micro piezoelectric driver.

10. Use according to claim 9, characterized in that, The preparation of the micro piezoelectric driver comprises co-firing the super-high inverse piezoelectric performance reduction-resistant sodium potassium niobate-based lead-free piezoelectric ceramic and a Ni electrode.

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