A lithium-doped nickel oxide / calcium manganate interface layer ceramic capacitor and its preparation method

Abstract

This invention discloses a lithium-doped nickel oxide / calcium manganate interface layer ceramic capacitor and its preparation method, wherein the method involves mixing CaMnO3 and Ni 1‑ x Li x O powder was ball-milled in polyvinyl alcohol, acetic acid solution, and deionized water, wherein O

Description

Technical Field

[0001] The present invention relates to the field of dielectric ceramic capacitors, and in particular to a lithium-doped nickel oxide / calcium manganate interface layer ceramic capacitor and a preparation method thereof. Background Art

[0002] With the rapid development of the semiconductor-based microelectronics industry, miniaturization, integration and good environmental stability of electronic components have become important development directions in the modern information field.

[0003] Since the 21st century, capacitors with small relative volume and large capacitance have been increasingly demanded, so high dielectric constant materials have wide potential applications in various aspects of the electronic technology field. Among them, liquid supercapacitors are widely used due to their large capacitance, but the risk factor is high caused by factors such as the fluidity of the electrolyte, which limits their application in energy equipment to a certain extent. Therefore, pure solid ceramic materials with high dielectric constant and large capacitance have great application prospects. Their high safety factor and large capacitance have greatly promoted the development of the electronic field.

[0004] At present, the large-capacity pure solid ceramic materials with high dielectric constant still have a dielectric constant of 10 3 , which is a relatively low value, and also has the disadvantages of small capacitance and large volume. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the present invention provides a lithium-doped nickel oxide / calcium manganate interface layer ceramic capacitor and a preparation method thereof, which improves the dielectric properties of ceramics through the combined action of doping modification, sintering matching and defect compensation, and has high dielectric constant, large capacitance and small volume.

[0006] The present invention is achieved through the following technical solutions:

[0007] A preparation method of a lithium-doped nickel oxide / calcium manganate interface layer ceramic capacitor, comprising the following steps:

[0008] S1, ball-milling CaMnO3 powder and Ni 1-x Li x O powder in a system of polyvinyl alcohol, acetic acid solution and deionized water respectively, wherein 0 < x < 0.07, then drying to a gel state, the CaMnO3 powder correspondingly obtains a first gel, and the Ni 1-x Li x O powder correspondingly obtains a second gel;

[0009] S2, preparing the first gel and the second gel into a first single-layer film and a second single-layer film sequentially by a tape rolling process, laminating the second single-layer film on both the upper and lower surfaces of the first single-layer film, then performing rolling molding to obtain a laminated film with a thickness of 250-300 μm;

[0010] S3, after removing the polyvinyl alcohol from the laminated film described in S2, heat it at 1300-1350℃ for 2-8 hours to obtain a lithium-doped nickel oxide / calcium manganate interface layer ceramic capacitor.

[0011] Preferably, the CaMnO3 powder and Ni described in S1 1-x Li x All O powders were first ground, then passed through a 120-mesh sieve, and then ball-milled.

[0012] Preferably, the CaMnO3 powder described in S1 is obtained through the following process:

[0013] CaCO3 and MnO2 were ball-milled evenly in a 1:1 molar ratio and then dried. The mixture was then passed through a 120-mesh sieve and heated from room temperature to 1050-1150℃ at a heating rate of 2-5℃ / min, and held at that temperature for 3-5 hours. Finally, the mixture was cooled to 200-500℃ at a cooling rate of 2-5℃ / min to obtain CaMnO3 powder.

[0014] Preferably, the Ni described in S1 1-x Li x O powder is obtained through the following process:

[0015] NiO and Li₂CO₃ were ball-milled uniformly at a molar ratio of (0.95-0.99):(0.005-0.025), dried, and then passed through a 120-mesh sieve. The mixture was then heated from room temperature to 1020-1080℃ at a heating rate of 2-5℃ / min and held at that temperature for 4-8 hours. Finally, it was cooled to 100-500℃ at a cooling rate of 2-5℃ / min to obtain Ni. 1-x Li x O powder.

[0016] Preferably, the polyvinyl alcohol in S1 is all CaMnO3 powder or Ni 1-x Li x 25% of the O powder mass, the volume ratio of acetic acid solution to deionized water is 1:33, and the deionized water is mixed with CaMnO3 powder or Ni 1-x Li x The mass ratio of O powder is 1:1, and the CaMnO3 powder or Ni powder is... 1-x Li x The O powder was ball-milled for 0.5–2 hours in a system of polyvinyl alcohol, acetic acid solution and deionized water.

[0017] Furthermore, the acetic acid solution has a mass percentage of 99%, and the deionized water is at a temperature of 80–100°C.

[0018] Preferably, the thickness of the first monolayer and the second monolayer in S2 is 100-150 μm.

[0019] Preferably, in S3, the laminated film described in S2 is first incubated at 700 to 800°C for 2 to 4h, and then incubated at 1300 to 1350°C.

[0020] Further, in S3, the laminated film described in S2 is heated from room temperature to 700 to 800°C at a heating rate of 0.2 to 1°C / min for incubation, and then heated from 700 to 800°C to 1300 to 1350°C at a heating rate of 2 to 5°C / min for incubation.

[0021] A lithium-doped nickel oxide / calcium manganite interface layer ceramic capacitor obtained by the preparation method of the lithium-doped nickel oxide / calcium manganite interface layer ceramic capacitor described in any one of the above items.

[0022] Compared with the prior art, the present invention has the following beneficial technical effects:

[0023] The preparation method of a lithium-doped nickel oxide / calcium manganite interface layer ceramic capacitor according to the present invention has simple process, low price of raw materials, low manufacturing cost and is environment-friendly. At room temperature, an ultra-high dielectric constant (10 5 ~10 7 ), the loss is greatly reduced, the insulation resistivity is high, the resistance is significantly improved, and the performance is excellent. It becomes an important candidate material for high-end industrial application materials, and at the same time provides ideas for the development of high-temperature co-fired ceramics and solid-state supercapacitors. By utilizing the matching of electrical conductivity, radial shrinkage and sintering temperature of P-type semiconductor ceramics and N-type semiconductor ceramics, CaMnO3 and Ni 1- x Li x O is firstly made into a single-layer film by a roll film process, then Ni 1-x Li x O single-layer films obtained from powder are laminated on the upper and lower surfaces of the single-layer film obtained from CaMnO3 powder, and finally roll-formed and co-fired to prepare an interface layer ceramic capacitor. Due to the co-firing, a high-resistance insulating layer is generated at the interface, which is conducive to charge storage, thereby obtaining excellent dielectric properties. This is the result of the action of the ceramic laminated co-fired interface layer, which can effectively reduce production costs. The present invention uses Ni modified by doping with appropriate concentration of Li ions 1-x Li x O (0<x<0.07) is co-fired with CaMnO3, and the two materials have opposite electrical charges, which enables a defect compensation mechanism to be formed at the contact surface to generate a high-resistance interface layer, which increases the capacitance per unit volume. It can be applied and promoted to the preparation of multi-layer ceramic capacitors, so that the prepared electronic products have large capacity, small volume and are easier to carry. Description of Drawings

[0024] Figure 1 Ni obtained in the embodiments of the present invention 1-x Li x XRD pattern of O.

[0025] Figure 2 This is the XRD pattern of CaMnO3 obtained in an embodiment of the present invention.

[0026] Figure 3 Ni obtained in the embodiments of the present invention 1-x Li x The conductivity of O varies with frequency.

[0027] Figure 4 The graph shows the change in conductivity of CaMnO3 with frequency obtained in an embodiment of the present invention.

[0028] Figure 5 Ni obtained in Example 1 of the present invention 0.97 Li 0.03 O / CaMnO3 / Ni 0.97 Li 0.03 Microscopic morphology of the cross section of the O-layered ceramic sample.

[0029] Figure 6 Ni obtained in Example 1 of the present invention 0.97 Li 0.03 O / CaMnO3 / Ni 0.97 Li 0.03 The dielectric constant of the O-layer ceramic sample varies with frequency.

[0030] Figure 7 Ni obtained in Example 1 of the present invention 0.97 Li 0.03 O / CaMnO3 / Ni 0.97 Li 0.03 The dielectric loss of the O-layer ceramic sample varies with frequency.

[0031] Figure 8 Ni obtained in Example 1 of the present invention 0.97 Li 0.03 O / CaMnO3 / Ni 0.97 Li 0.03 Complex impedance spectra of O-layered ceramic samples.

[0032] Figure 9 Ni obtained in Example 2 of the present invention 0.95 Li 0.05 O / CaMnO3 / Ni 0.95 Li 0.05 Microscopic morphology of the cross section of the O-layered ceramic sample.

[0033] Figure 10Ni obtained from Example 2 of the present invention 0.95 Li 0.05 O / CaMnO3 / Ni 0.95 Li 0.05 O is a graph showing the variation of dielectric constant of laminated ceramic samples with frequency.

[0034] Figure 11 Ni obtained from Example 2 of the present invention 0.95 Li 0.05 O / CaMnO3 / Ni 0.95 Li 0.05 O is a graph showing the variation of dielectric loss of laminated ceramic samples with frequency.

[0035] Figure 12 Ni obtained from Example 2 of the present invention 0.95 Li 0.05 O / CaMnO3 / Ni 0.95 Li 0.05 O is a complex impedance graph of the laminated ceramic sample.

[0036] Figure 13 is a mechanism diagram of the present invention for producing good dielectric properties. DETAILED DESCRIPTION

[0037] The present invention will be described in detail below with reference to the accompanying drawings and examples, but the present invention is not limited to the following examples.

[0038] The invention discloses a preparation method of a lithium-doped nickel oxide / calcium manganite interface layer ceramic capacitor, comprising the following steps:

[0039] Step 1, prepare CaMnO3 powder and Ni 1-x Li x O (0<x<0.07) powder respectively, grind the two powders and pass through a 120-mesh sieve;

[0040] Step 2, add polyvinyl alcohol (PVA) accounting for 25% of the powder mass, acetic acid solution (99%) and hot water at 80-100°C respectively, and carry out ball milling for 0.5-2h, the volume ratio of acetic acid solution to hot water is 1:33; adding polyvinyl alcohol is to provide viscosity and toughness for subsequent tape calendering, adding hot water is to reduce the viscosity of polyvinyl alcohol during ball milling so that it can be uniformly dispersed, and acetic acid is to avoid the reaction between polyvinyl alcohol and slurry and eliminate bubbles generated during ball milling. The mass ratio of CaMnO3 to Ni 1- x Li x O to hot water is both 1:1, then dried to a gel state;

[0041] Step 3: Perform a rolling process separately to make both films into 100-150 μm monolayers. Through the same process, two Ni atoms are obtained. 1-x Li x O single-layer film, then the two films are laminated and rolled together, Ni 1-x Li x O monolayer films are located on the upper and lower surfaces of CaMnO3 monolayer films, respectively, to obtain stacked films with a thickness of 250-300 μm;

[0042] Step 4: The temperature was increased from room temperature to 700–800°C in air at a rate of 0.2–1°C / min and held for 2–4 hours to remove PVA. Then, the temperature was increased to 1300–1350°C at a rate of 2–5°C / min and held for 2–8 hours to obtain Ni. 1-x Li x O / CaMnO3 / Ni 1-x Li x O-interface layer ceramic capacitor.

[0043] Reference Figure 13 The mechanism for obtaining good dielectric properties is Ni 1-x Li x A high-resistivity insulating layer is formed at the interface between O and CaMnO3 (i.e., the high-resistivity interface layer in the figure). The main reason for the high-resistivity state at the interface is the structural anisotropy of the two materials; Ni... 1-x Li x O represents rock salt minerals, CaMnO3 represents perovskite, and Ni represents... 0.95 Li 0.05 O and CaMnO3 are p-type and n-type semiconductor ceramics, respectively, with opposite charges. This leads to a defect compensation mechanism at the contact surface, resulting in decreased conductivity. For example, Ni and Li ions can be lightly dissolved in CaMnO3 to form acceptor doping, thereby improving the interfacial insulation.

[0044] Example 1

[0045] The chemical formula of this interface layer ceramic capacitor is Ni. 1-x Li x O / CaMnO3 / Ni 1-x Li x O, where x represents the mole percentage and x = 0.03, specifically includes the following steps:

[0046] (1) According to the chemical formula CaMnO3, analytical grade CaCO3 and MnO2 were prepared in a molar ratio of 1:1 and mixed evenly by mechanical ball milling. Then, the mixture was dried, passed through a 120-mesh sieve, and then heated from room temperature to 1100℃ at a heating rate of 3℃ / min, held for 4h, and then cooled to 300℃ at a cooling rate of 3℃ / min. The mixture was then cooled to room temperature in the furnace to synthesize CaMnO3 powder.

[0047] According to the chemical formula Ni 1-x Li x O(x=0.03) was prepared by mixing analytically pure NiO and Li2CO3 at a molar ratio of 0.97:0.015 using mechanical ball milling. The mixture was then dried, passed through a 120-mesh sieve, and heated from room temperature to 1050℃ at a rate of 3℃ / min, held at that temperature for 6 hours, and then cooled to 300℃ at a rate of 3℃ / min. The mixture was then cooled to room temperature in the furnace to synthesize Ni. 0.97 Li 0.03 O powder;

[0048] (2) CaMnO3 powder and Ni 0.97 Li 0.03 The O powder was ground again and passed through a 120-mesh sieve to obtain uniformly sized CaMnO3 powder and Ni. 0.97 Li 0.03 O powder;

[0049] (3) Add polyvinyl alcohol, 99% acetic acid solution and 90℃ hot water to the obtained CaMnO3 powder and ball mill for 40 min. The polyvinyl alcohol is 25% of the mass of CaMnO3 powder, the volume ratio of acetic acid solution and hot water is 1:33, the mass ratio of CaMnO3 and 90℃ hot water is 1:1, and dry to gel state, which is recorded as gel A.

[0050] In the obtained Ni 0.97 Li 0.03 O powder was ball-milled for 40 minutes with polyvinyl alcohol, 99% acetic acid solution, and 90°C hot water. Polyvinyl alcohol is Ni... 0.97 Li 0.03 O powder mass 25%, acetic acid solution and hot water volume ratio 1:33, Ni 0.97 Li 0.03 The mass ratio of O and 90℃ hot water is 1:1. After drying to a gel state, it is denoted as gel B. Two gels B are obtained through the same process.

[0051] (4) Perform rolling processes to make gel A and gel B into 120μm single-layer films, and then roll the two films together to form a 280μm laminated film, with gel B located on the upper and lower surfaces of gel A respectively.

[0052] (5) The laminated film was heated from room temperature to 750℃ in air at a heating rate of 0.5℃ / min, held at that temperature for two hours, and then heated to 1320℃ at a heating rate of 2℃ / min and held at that temperature for 3 hours to obtain Ni. 1-x Li x O / CaMnO3 / Ni 1-x Li xO-interface layer ceramic capacitor;

[0053] Reference Figure 1 and Figure 2 ,Depend on Figure 1 It can be seen that pure-phase Ni was synthesized when x = 0.03. 0.99 Li 0.03 O ceramic powder, made from Figure 2 It can be seen that pure-phase CaMnO3 ceramic powder was synthesized.

[0054] Reference Figure 3 and Figure 4 ,Depend on Figure 3 It can be seen that the prepared monolayer Ni 0.99 Li 0.03 O-ceramics maintain good electrical conductivity (~0.15 S / cm) and this conductivity does not change with frequency. Figure 4 It can be seen that the monolayer CaMnO3 ceramic maintains good electrical conductivity (~0.035S / cm).

[0055] Reference Figure 5 It can be seen that Ni 0.97 Li 0.03 O / CaMnO3 / Ni 0.97 Li 0.03 Ni located on the upper and lower surfaces of the O-interface layer ceramic capacitor 0.97 Li 0.03 The O layer and the CaMnO3 layer have a tight contact, and the interface is clear and smooth. It should be noted that... Figure 5 The two dark black sections at the top and bottom are part of the test setup and do not belong to the interface layer ceramic capacitor.

[0056] After the sintered sample is polished and cleaned in step (5), silver electrode paste is evenly coated on both sides, and heat-treated at 550℃ for 25 minutes. Dielectric performance is then tested according to relevant standards.

[0057] Reference Figure 6 It can be seen that Ni 0.97 Li 0.03 O / CaMnO3 / Ni 0.97 Li 0.03 The O-interface layer ceramic capacitor has a dielectric constant of ~10 at 0.05 Hz. 5 .

[0058] Reference Figure 7 From the overall trend of its curve, it can be seen that Ni 0.97 Li 0.03 O / CaMnO3 / Ni 0.97 Li 0.03The dielectric loss of the O-interface layer ceramic capacitor at 0.05 Hz is ~10, which is comparable to that of Ni. 0.97 Li 0.03 The O and CaMnO3 monolayers decreased by three orders of magnitude.

[0059] Reference Figure 8 The intercept of the impedance spectrum represents the resistance of the sample under the measurement voltage. After removing the shape factor, the resistance of Ni can be obtained. 0.97 Li 0.03 O / CaMnO3 / Ni 0.97 Li 0.03 The resistivity of the O-interface layer ceramic capacitor is increased to 10. 7 Ω·cm means that the conductivity has dropped to 10. -7 S / cm significantly improves the resistance value.

[0060] Example 2

[0061] The chemical formula of this interface layer ceramic capacitor is: Ni 1-x Li x O / CaMnO3 / Ni 1-x Li x O, where x represents the mole percentage and x = 0.05, specifically includes the following steps:

[0062] (1) According to the chemical formula CaMnO3, analytical grade CaCO3 and MnO2 were prepared and mixed evenly by mechanical ball milling. Then, the mixture was dried, passed through a 120-mesh sieve, heated to 1100℃ at a heating rate of 3℃ / min, held for 4h, and then cooled to 300℃ at a cooling rate of 3℃ / min. The mixture was then cooled to room temperature in the furnace to synthesize CaMnO3 powder.

[0063] According to the chemical formula Ni 1-x Li x O(x=0.05) Analytical grade NiO and Li2CO3 were prepared at a molar ratio of 0.95:0.025 and mixed uniformly by mechanical ball milling. The mixture was then dried, passed through a 120-mesh sieve, and heated to 1050℃ at a rate of 3℃ / min, held at that temperature for 6 hours, and then cooled to 300℃ at a rate of 3℃ / min. The mixture was then cooled to room temperature in the furnace to synthesize Ni. 0.95 Li 0.05 O powder;

[0064] (2) CaMnO3 powder and Ni 0.97 Li 0.03 The O powder was ground again and passed through a 120-mesh sieve to obtain uniformly sized CaMnO3 powder and Ni. 0.95 Li 0.05 O powder;

[0065] (3) Add polyvinyl alcohol, 99% acetic acid solution and 95℃ hot water to the obtained CaMnO3 powder and ball mill for 40 min. The polyvinyl alcohol is 25% of the mass of CaMnO3 powder, the volume ratio of acetic acid solution to hot water is 1:33, the mass ratio of CaMnO3 to 95℃ hot water is 1:1, and dry to gel state, which is recorded as gel A.

[0066] In the obtained Ni 0.97 Li 0.03 Polyvinyl alcohol, 99% acetic acid solution, and hot water were added to the O powder and ball-milled for 40 minutes. The polyvinyl alcohol was 25% of the mass of the CaMnO3 powder, and the volume ratio of acetic acid solution to hot water was 1:33. Ni 0.97 Li 0.03 The mass ratio of O and 95℃ hot water is 1:1. After drying to a gel state, it is denoted as gel B. Two gels B are obtained through the same process.

[0067] (4) Perform rolling processes to make gel A and gel B into 120μm single-layer films, and then roll the two films together to form a 300μm laminated film, with gel B located on the upper and lower surfaces of gel A respectively.

[0068] (5) The laminated film was heated from room temperature to 750℃ in air at a heating rate of 0.5℃ / min, held at that temperature for two hours, and then heated to 1300℃ at a heating rate of 2℃ / min and held at that temperature for 3 hours to obtain Ni. 0.95 Li 0.05 O / CaMnO3 / Ni 0.95 Li 0.05 O-interface layer ceramic capacitor;

[0069] Reference Figure 1 and Figure 2 ,Depend on Figure 1 It can be seen that pure-phase Ni was synthesized when x = 0.05. 0.99 Li 0.05 O ceramic powder, made from Figure 2 It can be seen that pure-phase CaMnO3 ceramic powder was synthesized.

[0070] Reference Figure 3 and Figure 4 ,Depend on Figure 3 It can be seen that the prepared monolayer Ni 0.99 Li 0.03 O-ceramics maintain good electrical conductivity (~0.2 S / cm) and this conductivity does not change with frequency. Figure 4 It can be seen that the monolayer CaMnO3 ceramic maintains good electrical conductivity (~0.035S / cm).

[0071] Reference Figure 9 It can be seen that Ni0.95 Li 0.05 O / CaMnO3 / Ni 0.95 Li 0.05 Ni interface layer ceramic capacitor 0.95 Li 0.05 The O layer and the CaMnO3 layer are in close contact, and the interface is clear and flat, which also indicates that there is no diffusion of elements other than Li.

[0072] After the sintered sample is polished and cleaned in step (5), silver electrode paste is evenly coated on both sides, and heat-treated at 550℃ for 25 minutes. Dielectric performance is then tested according to relevant standards.

[0073] Reference Figure 10 It can be seen that Ni 0.95 Li 0.05 O / CaMnO3 / Ni 0.95 Li 0.05 O-interface layer ceramic capacitor, dielectric constant >10 at 0.05Hz. 6 .

[0074] Reference Figure 11 It can be seen that Ni 0.95 Li 0.05 O / CaMnO3 / Ni 0.95 Li 0.05 The dielectric loss of the O-interface layer ceramic capacitor decreases to ~5 at 0.05 Hz.

[0075] Reference Figure 12 The intercept of the impedance spectrum represents the resistance of the sample under the measurement voltage. After removing the shape factor, the resistance of Ni can be obtained. 0.95 Li 0.05 O / CaMnO3 / Ni 0.95 Li 0.05 The resistivity of the O-interface layer ceramic capacitor is increased to >10. 5 Ω·cm means that the conductivity has dropped to <10 -5 The resistance was significantly optimized by S / cm.

[0076] Example 3

[0077] The chemical formula of this interface layer ceramic capacitor is: Ni 1-x Li x O / CaMnO3 / Ni 1-x Li x O, where x represents the mole percentage and x = 0.01, specifically includes the following steps:

[0078] (1) According to the chemical formula CaMnO3, analytical grade CaCO3 and MnO2 were prepared and mixed evenly by mechanical ball milling. Then, the mixture was dried, passed through a 120-mesh sieve, heated to 1100℃ at a heating rate of 3℃ / min, held for 4h, and then cooled to 300℃ at a cooling rate of 3℃ / min. The mixture was then cooled to room temperature in the furnace to synthesize CaMnO3 powder.

[0079] According to the chemical formula Ni 1-x Li x O(x=0.01) was prepared by mixing analytically pure NiO and Li2CO3 at a molar ratio of 0.99:0.005 using mechanical ball milling. The mixture was then dried, passed through a 120-mesh sieve, and heated to 1050℃ at a rate of 3℃ / min, held for 6 hours, and then cooled to 300℃ at a rate of 3℃ / min. The mixture was then cooled to room temperature in the furnace to synthesize Ni. 0.95 Li 0.05 O powder;

[0080] (2) CaMnO3 powder and Ni 0.99 Li 0.01 The O powder was ground again and passed through a 120-mesh sieve to obtain uniformly sized CaMnO3 powder and Ni. 0.99 Li 0.01 O powder;

[0081] (3) Add polyvinyl alcohol, 99% acetic acid solution and 90℃ hot water to the obtained CaMnO3 powder and ball mill for 50 min. The polyvinyl alcohol is 25% of the mass of CaMnO3 powder, the volume ratio of acetic acid solution and hot water is 1:33, and the mass ratio of CaMnO3 and 90℃ hot water is 1:1. Dry until gel-like and record as gel A.

[0082] In the obtained Ni 0.99 Li 0.01 Polyvinyl alcohol, 99% acetic acid solution, and hot water were added to the O powder and ball-milled for 50 min. The polyvinyl alcohol content was 25% of the mass of the CaMnO3 powder, and the volume ratio of acetic acid solution to hot water was 1:33. Ni 0.99 Li 0.01 The mass ratio of O and 90℃ hot water is 1:1. The mixture is dried until it becomes gel-like and is denoted as gel B.

[0083] (4) Perform rolling processes separately to make gel A and gel B into 130μm single-layer films, and then roll the two films together to form a 300μm laminated film.

[0084] (5) The laminated film was placed in air and heated from room temperature to 750°C at a heating rate of 0.5°C / min, held at that temperature for two hours, and then heated to 1330°C at a heating rate of 2°C / min and held at that temperature for 3 hours to obtain Ni.0.99 Li 0.01 O / CaMnO3 / Ni 0.99 Li 0.01 O-interface layer ceramic capacitor.

Claims

1. A method for preparing a lithium-doped nickel oxide / calcium manganate interface layer ceramic capacitor, characterized in that, Includes the following steps: S1, CaMnO3 powder and Ni 1-x Li x The O powder was ball-milled for 0.5–2 hours in a system of polyvinyl alcohol, acetic acid solution, and deionized water. The polyvinyl alcohol content was all CaMnO3 powder or Ni. 1-x Li x 25% of the O powder mass, acetic acid solution and deionized water volume ratio of 1:33, deionized water and CaMnO3 powder or Ni 1-x Li x The mass ratio of O powder is 1:1, where 0 < x <0.07, then dried to a gel state, CaMnO3 powder corresponding to the first gel, Ni 1-x Li x O powder corresponds to the second gel; The CaMnO3 powder is obtained as follows: CaCO3 and MnO2 are ball-milled evenly in a 1:1 molar ratio and then dried. The mixture is then passed through a 120-mesh sieve, heated from room temperature to 1050-1150 ℃ at a heating rate of 2-5 ℃ / min, and held at that temperature for 3-5 h. Finally, the temperature is cooled to 200-500 ℃ at a cooling rate of 2-5 ℃ / min to obtain the CaMnO3 powder. The Ni 1-x Li x NiO powder is obtained as follows: NiO and Li2CO3 are ball-milled uniformly in a molar ratio of (0.95-0.99):(0.005-0.025), dried, and then passed through a 120-mesh sieve. The temperature is then increased from room temperature to 1020-1080 °C at a heating rate of 2-5 °C / min and held for 4-8 h. Finally, the temperature is decreased to 100-500 °C at a cooling rate of 2-5 °C / min to obtain Ni. 1- x Li x O powder; S2, the first gel and the second gel are sequentially made into a first monolayer film and a second monolayer film by a rolling process. The second monolayer film is stacked on both the upper and lower surfaces of the first monolayer film and then rolled to form a laminated film with a thickness of 250-300 μm. S3, after removing the polyvinyl alcohol from the laminated film described in S2, keep it at 1300-1350 ℃ for 2~8 h to obtain a lithium-doped nickel oxide / calcium manganate interface layer ceramic capacitor.

2. The method for preparing a lithium-doped nickel oxide / calcium manganate interface layer ceramic capacitor according to claim 1, characterized in that, The CaMnO3 powder and Ni mentioned in S1 1-x Li x All O powders were first ground, then passed through a 120-mesh sieve, and then ball-milled.

3. The method for preparing a lithium-doped nickel oxide / calcium manganate interface layer ceramic capacitor according to claim 1, characterized in that, The acetic acid solution has a mass percentage of 99%, and the deionized water is at a temperature of 80~100℃.

4. The method for preparing a lithium-doped nickel oxide / calcium manganate interface layer ceramic capacitor according to claim 1, characterized in that, In S2, the thickness of both the first and second monolayer films is 100-150 μm.

5. The method for preparing a lithium-doped nickel oxide / calcium manganate interface layer ceramic capacitor according to claim 1, characterized in that, S3 first heats the laminated film described in S2 at 700~800 ℃ for 2~4 h, and then heats it at 1300-1350 ℃.

6. The method for preparing a lithium-doped nickel oxide / calcium manganate interface layer ceramic capacitor according to claim 5, characterized in that, S3 heats the laminated film described in S2 from room temperature to 700-800℃ at a heating rate of 0.2-1℃ / min and holds it thereafter, and then heats it from 700-800℃ to 1300-1350℃ at a heating rate of 2-5℃ / min and holds it thereafter.

7. A lithium-doped nickel oxide / calcium manganate interface layer ceramic capacitor obtained by the preparation method of the lithium-doped nickel oxide / calcium manganate interface layer ceramic capacitor according to any one of claims 1-6.

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