JP6362883B2 - Solid ion capacitor and method of manufacturing solid ion capacitor - Google Patents

Description

  The present application relates to a solid ion capacitor and a method of manufacturing the solid ion capacitor.

  In the field of capacitors, film capacitors, ceramic capacitors, mica capacitors, electrolytic capacitors and the like have been developed and used. Among these, electrolytic capacitors using an electrolytic solution have characteristics such as a large capacity, and are widely used for smoothing power supply circuits.

  Since the electrolytic solution is used for the electrolytic capacitor as described above, it may be difficult to reliably hold the electrolytic solution in the container for a long period of time depending on the use conditions. When leakage of the electrolytic solution occurs, a change in characteristics such as a decrease in the capacity of the electrolytic capacitor occurs.

For this reason, it has been proposed to realize a capacitor using an ionic conductor instead of an electrolytic solution as a solid material capacitor that is equal to or larger than the capacity of the electrolytic capacitor, and has been actively studied in recent years. Such a solid material is called an ionic conductor or a solid electrolyte, and in particular, an ionic conductor capable of conducting hydrogen ions, lithium ions, sodium ions, oxygen ions, and the like has attracted attention. This is because a solid material capable of conducting these ions can be used for a device that stores and converts energy, such as a fuel cell, a secondary battery, a capacitor, and hydrogen generation. For example, Patent Document 1 discloses Li _{1 + X} M ¹ _X Ti _2-X (PO ₄ ) ₃ (where M ¹ is at least one metal selected from the group consisting of Al, Y, Ga, In, and La). And 0 ≦ X ≦ 0.6), Na _{1 + γ} Zr _2-β Y _β P _3-γ Si _γ O ₁₂ (where 0 ≦ γ ≦ 3, 0 ≦ β ≦ 2), Na _{1 + α} M ⁴ _α M ⁵ _2-α (PO ₄ ) ₃ (where M ⁴ is at least one metal selected from Al and In, and M ⁵ is Ge, Sn, Ti, Zr) , And at least one metal selected from the group consisting of Hf, and 0 ≦ α ≦ 2), and an electrode such as gold or nickel formed by sputtering. An electric double layer capacitor is disclosed.

JP 2008-130844 A

  In an electric double layer capacitor using an ionic conductor instead of an electrolytic solution, the dielectric constant of the ionic conductor affects the capacitance of the electric double layer capacitor. In the electric double layer capacitor disclosed in Patent Document 1, it is difficult to realize an electric double layer capacitor having a sufficiently large capacity as compared with a conventional electrolytic capacitor. An object of this invention is to provide the solid ion capacitor which can be provided with a big capacity | capacitance, and its manufacturing method.

  The solid ion capacitor of the present invention is composed of a first electrode layer containing Ag and a second electrode layer, and a solid electrolyte material made of ceramics containing Na, and is located between the first electrode layer and the second electrode layer. An electrolyte layer, the metal material and the solid electrolyte material distributed intricately, and between the first electrode layer and the electrolyte layer, and between the second electrode layer and the electrolyte layer An interfacial composite layer provided on at least one of them, and the first or second electrode layer and the metal material of the interfacial composite layer are electrically connected.

  The electrolyte layer, the first and second electrode layers, and the interface composite layer preferably constitute a co-sintered body.

  The interface composite layer preferably contains the metal material in a proportion of 30% to 70% with respect to the total volume of the metal material and the solid electrolyte material.

The ceramics having a composition represented by _{Na 1 + x + y (Al} y Zr 2-y) (Si x P 3-x) O 12, 0 ≦ x ≦ 2,0 <y ≦ 0.4 Is preferred.

  The solid ion capacitor includes a plurality of each of the electrolyte layer, the interface composite layer, the first electrode layer, and the second electrode layer, and includes a plurality of the electrolyte layer, the interface composite layer, and the first electrode layer. The electrode layer and the second electrode layer are laminated, the first electrode layer and the second electrode layer are alternately positioned in the lamination direction, and the electrolyte layer is the first electrode layer. Located between the electrode layer and the second electrode layer, the interface composite layer is formed between the first electrode layer and the electrolyte layer, and between the second electrode layer and the electrolyte layer. Each may be provided between them.

  The solid ion capacitor manufacturing method of the present invention includes a pair of metal paste layers, a green sheet for an electrolyte layer positioned between the pair of metal paste layers, one of the pair of metal paste layers, and the green for the electrolyte layer. Forming a green sheet laminate including a green sheet for an interfacial composite layer positioned between at least one of the sheet and the other of the pair of metal paste layers and the green sheet for the electrolyte layer; and the green sheet Including the step of co-sintering the pair of metal paste layers, the electrolyte layer green sheet and the interfacial composite layer green sheet by holding the laminate at a temperature of 850 ° C. or higher and 1000 ° C. or lower, The metal paste contains Ag, and the green sheet for ceramics includes a raw material of a main component of ceramics. Te, including the Na.

The ceramic green sheet, as a material of the main component of the ceramics, Na, Al, Zr, P, and Si, after _{sintering, Na 1 + x + y (} Al y Zr 2-y) (Si x P 3- _x ) O ₁₂ ,
It is preferable to include the composition ratio represented by 0 ≦ x ≦ 2 and 0 <y ≦ 0.4.

  According to the present invention, by including the interface composite layer, the area of the electrode in contact with the solid electrolyte material can be increased, and a solid ion capacitor having a large capacity can be realized.

(A) is one Embodiment of the solid ion capacitor of this invention, Comprising: It is typical sectional drawing which shows the form of a single plate capacitor, (b) expands the interface composite layer of a solid ion capacitor. It is a schematic diagram shown. (A) to (e) are process cross-sectional views showing a method of manufacturing the solid ion capacitor shown in FIG. It is one Embodiment of the solid ion capacitor of this invention, Comprising: It is typical sectional drawing which shows the form of a multilayer capacitor. FIGS. 4A to 4D are process cross-sectional views illustrating a method of manufacturing the solid ion capacitor shown in FIG. The frequency characteristic of a dielectric constant in the solid ion capacitor of an Example and a comparative example is shown. (A)-(d) shows the SEM image of the cross section which carried out the mirror surface polishing of the solid ion capacitor of an Example.

  Hereinafter, embodiments of the solid ion capacitor of the present embodiment will be described with reference to the drawings. The solid ion capacitor of the present invention can be implemented in any form of a single plate capacitor and a multilayer capacitor.

(Single plate capacitor)
FIG. 1A schematically shows a cross-sectional structure of the solid ion capacitor 11 of the present embodiment. The solid ion capacitor 11 includes an electrolyte layer 1, first and second electrode layers 2 and 3, and first and second interface composite layers 32 and 33. The electrolyte layer 1, the first and second electrode layers 2 and 3, and the first and second interface composite layers 32 and 33 constitute a co-sintered body 7 as a whole. In the present embodiment, the solid ion capacitor 11 includes the first and second interface composite layers 32 and 33, but may include only one of them.

  The electrolyte layer 1 is made of a ceramic solid electrolyte layer containing Na. Further, it is located between the electrode layers 2 and 3.

The ceramic of the ion conductor containing Na used for the electrolyte layer 1 has a composition represented by A · M ₂ (XO ₄ ) ₃ . The oxide represented by the composition formula of A · M ₂ (XO ₄ ) ₃ has a NASICON type crystal structure. Here, A is an alkali metal, M is a transition metal, and X is S, P, As, Mo, W, or the like. The NASICON crystal structure is a three-dimensional structure in which an octahedron in which oxygen is located at the vertex indicated by the composition of MO ₆ and a tetrahedron in which oxygen is located at the vertex indicated by the composition of XO ₄ share the oxygen at the vertex. It is constituted by arranging in order.

For example, when it is composed of elements of Na, Al, Zr, P, and Si, Al and Zr are located at the M site of the NASICON type crystal structure, and P and Si are located at the X site. Since Zr is a tetravalent element and Al is a trivalent element, the ceramic further contains an amount of Na corresponding to the amount obtained by replacing Zr with Al. In addition, since P is a pentavalent element and Si is a tetravalent element, the ceramic further includes an amount of Na corresponding to the amount of P substituted with Si. This crystal structure has large gaps between the octahedrons and tetrahedrons described above, and Na ⁺ ions or the like can be inserted into the gaps. Also, the inserted Na ⁺ ions can be moved by applying electrolysis. As a preferable form, for example, it is represented by the following composition formula (1).

_{Na 1 + x + y (Al} y Zr 2-y) (Si x P 3-x) O 12
Here, 0 ≦ x ≦ 2, 0 <y ≦ 0.4 Formula (1)

  The first and second electrode layers 2 and 3 contain Ag. According to a detailed examination by the inventors of the present application, when a ceramic material having a NASICON crystal structure containing Li and a metal material containing Ag are co-sintered, substitution of Li and Ag occurs, and an electrode is formed. Ag disappears. On the other hand, Ag does not disappear even if a ceramic material having a NASICON crystal structure containing Na and not containing Li and a metal material containing Ag are co-sintered. I understood. Further, it was found that other elements constituting the ceramic do not react with Ag and do not greatly affect the electrode layer.

  Therefore, a ceramic green sheet containing Na, Al, Zr, P, and Si is disposed between a pair of metal material layers and co-sintered so as to satisfy the composition formula (1). The co-sintered body 7 including the first and second electrode layers 2 and 3 and the electrolyte layer 1 positioned therebetween can be obtained. According to this embodiment, a manufacturing process can be shortened compared with the case where an electrode layer is formed later, manufacturing time and manufacturing cost can be reduced. Moreover, the solid ion capacitor which does not contain electrolyte solution is excellent in long-term reliability.

  The metal material of the first and second electrode layers 2 and 3 is highly conductive and sufficiently contracts at a temperature at which it can be co-sintered with the electrolyte layer 1, and diffuses and disappears into the electrolyte layer 1 and the like after co-sintering It is preferable that the material does not constitute the electrode layer. In addition, the metal material of the first and second electrode layers 2 and 3 includes the control of the sintering temperature, the denseness of the first and second electrode layers 2 and 3 after the sintering, and the first and second interfaces. In order to control the adhesion with the composite layers 32 and 33, an additive such as glass may be included. For example, the first and second electrode layers 2 and 3 are preferably made of Ag single metal, and the metal material containing Ag may contain unavoidable impurities. Moreover, the glass for shrinkage | contraction amount adjustment etc. may be included. In order to use as a capacitor, the first electrode layer and the second electrode layer preferably include the same metal material.

  The ceramic according to the present embodiment has a composition satisfying the composition formula (1), whereby the co-sintered body 7 can be sintered at a temperature of 850 ° C. or higher. In particular, when the metal material of the first and second electrode layers 2 and 3 is Ag, the co-sintered body 7 is at a temperature of 850 ° C. or higher and 950 ° C., which is slightly lower than 962 ° C. which is the melting point of Ag. Co-sintering is possible, and a dense co-sintered body 7 can be obtained. In particular, when the composition ratio x, y in the composition formula (1) satisfies 0.1 ≦ x ≦ 0.67 and 0.1 ≦ y ≦ 0.4, the co-sintered body 7 is 850 ° C. or higher and 1000 or lower. It was found that the dielectric constant of the electrolyte layer 1 in the obtained solid ion capacitor 11 was 3000 or more, and it was possible to realize a high-capacitance capacitor with a high dielectric constant.

  The first and second interface composite layers 32 and 33 include the metal material of the first and second electrode layers 2 and 3 and the solid electrolyte material of the electrolyte layer 1, respectively. The first interface composite layer 32 is located between the first electrode layer 2 and the electrolyte layer 1, and the second interface composite layer 33 is located between the second electrode layer 3 and the electrolyte layer 1. doing.

  The metal material and the solid electrolyte material may be one selected from the above-described plurality of materials used for the first and second electrode layers 2, 3 and the electrolyte layer 1, respectively. As long as it is selected from the materials described above, the material used for the first and second electrode layers 2 and 3 and the electrolyte layer 1 may be different from the material used for the first and second interface composite layers 32 and 33. Good. However, as will be described below, the first and second electrode layers 2 and 3 and the electrolyte can be used in terms of stress relaxation and improvement in adhesion between the first and second electrode layers 2 and 3 and the electrolyte layer 1. The material used for the layer 1 and the material used for the first and second interface composite layers 32 and 33 are preferably the same. As described above, the solid electrolyte material is a ceramic having a NASICON type crystal structure having ion conductivity.

  FIG. 1B is a schematic view showing the vicinity of the first interface composite layer 32 in an enlarged manner. As shown in FIG. 1B, in the first interface composite layer 32, the metal material 34 and the solid electrolyte material 35 are intricately distributed.

The metal material 34 of the first interface composite layer 32 is in contact with and electrically connected to the first electrode layer 2. The solid electrolyte material 35 of the first interface composite layer 32 is in contact with the electrolyte layer 1, and Na ⁺ ions can move between the electrolyte layer 1 and the solid electrolyte material 35 of the first interface composite layer 32. It is.

  Although not shown, the second interface composite layer 33 is positioned symmetrically with the first interface composite layer 32 with the electrolyte layer 1 interposed therebetween, and has the same structure as the first interface composite layer 32. For this reason, the contact area between the metal material 34 and the solid electrolyte material 35 is larger than the contact area when the first and second metal layers 2 and 3 and the electrolyte layer 1 are in direct contact. Thereby, in the solid ion capacitor 11, the metal material 34 of the first interface composite layer 32 and the second interface composite layer 33 functions as an enlarged surface of the first electrode layer 2 and the second electrode layer 3. To do. Therefore, the capacity of the solid ion capacitor 11 is increased by increasing the electrode area of the capacitor.

However, in the first interface composite layer 32, the portion of the metal material 34 that is not electrically connected to the first electrode layer 2 and the portion of the solid electrolyte material 35 that is not connected to the electrolyte layer 1 are the first Electrons cannot be conducted from the electrode layer 2 and Na ⁺ ions cannot move between the electrode layer 2 and the electrode layer 2. The same applies to the second interface composite layer 33.

  For this reason, in the 1st interface composite layer 32 and the 2nd interface composite layer 33, it is preferable that the metal material 34 is mutually connected as much as possible and there are few isolated parts. Similarly, in the first interface composite layer 32 and the second interface composite layer 33, it is preferable that the solid electrolyte materials 35 are connected to each other as much as possible, and there are few isolated portions.

  According to a detailed study by the inventor of the present application, the first interface composite layer 32 and the second interface composite layer 33 each have the metal material 34 to the total volume of the metal material 34 and the solid electrolyte material 35. It was found that the metal material 34 and the solid electrolyte material 35 have a substantially connected structure as long as it is contained in a proportion of 30% to 70%. When the ratio of the metal material 34 is less than 30% by volume, a part of the metal material 34 included in the first interface composite layer 32 and the second interface composite layer 33 is easily isolated. Further, when the proportion of the metal material exceeds 70%, a part of the electrolyte material 35 is easily isolated.

  When such an interface is made into a composite, the contact surface increases due to the complicated structure of metal particles and solid electrolyte material particles, compared to the case where there is no composite. This means that the electrode area has been increased, which is advantageous as a capacitor.

  The first and second interface composite layers 32 and 33 alleviate the stress difference between the electrolyte layer 1 and the first and second electrode layers 2 and 3 in the co-sintered body 7 and improve the adhesion. Let As described above, the electrolyte layer 1 and the first and second electrode layers 2 and 3 are made of different materials. For this reason, the shrinkage rates during the sintering are also different from each other, and stress can be generated at the interface between the electrolyte layer 1 and the first and second electrode layers 2 and 3. In addition, since the electrolyte layer 1 and the first and second electrode layers 2 and 3 include different materials, when the electrolyte layer 1 and the first and second electrode layers 2 and 3 are in contact with each other, different materials are used. Therefore, the adhesion may not be good.

  On the other hand, the first and second interface composite layers 32 and 33 include the metal material of the first and second electrode layers 2 and 3 and the solid electrolyte material of the electrolyte layer 1, and these materials are Since they are intricately distributed, in the first and second interface composite layers 32 and 33, stress due to shrinkage of the two sintered materials is relieved and adhesion is improved.

  The solid ion capacitor 11 can be used in various applications with the co-sintered body 7 including the electrolyte layer 1, the first and second electrode layers 2 and 3, and the first and second interface composite layers 32 and 33. It may be used, or the co-sintered body 7 may be covered with a resin. For example, the solid ion capacitor 11 includes a pair of extraction electrodes 5, solder 4 that electrically connects the pair of extraction electrodes 5 to the first and second electrode layers 2 and 3, and the solder 4 and the extraction electrode 5. You may further provide the resin mold 6 which covers the provided co-sintered body 7 whole. Preferably, by forming the circuit by simultaneous firing with other elements such as a resistor and a coil, the number of circuit manufacturing steps can be reduced.

In the solid ion capacitor 11 of this embodiment, for example, when the first electrode layer 2 is connected to a high potential and the second electrode layer 3 is connected to a low potential, Na ⁺ ions in the electrolyte layer 1 are It moves to the electrode layer 3 side. Since Na ⁺ ions do not move to the second electrode layer 3 that is not an ion conductor, positive charges due to Na ⁺ ions are accumulated on the second electrode layer 3 side in the electrolyte layer 1, and Na ⁺ ions are Negative charges resulting from the movement are accumulated on the first electrode layer 2 side. For this reason, the solid ion capacitor 11 functions as a capacitor. Further, by providing the first and second interface composite layers 32 and 33, which are a composite of both, at the interface between the first and second electrode layers 2 and 3 and the solid electrolyte layer 1, the effective electrode area can be reduced. Since it can be increased, a capacitor having a large capacitance can be obtained.

  Next, a method for manufacturing the solid ion capacitor 11 will be described with reference to FIG. The solid ion capacitor 11 can be manufactured by the same method as the conventional LTCC manufacturing method.

  First, raw materials containing Na, Al, Zr, P, and Si are prepared as ceramic raw materials. For example, oxides, carbonates, oxalates, ammonium salts, and the like each containing Na, Al, Zr, P, and Si are weighed with the content ratio shown in the above composition formula (1).

Examples of raw materials containing Na, Al, Zr, P and Si include Na ₂ CO ₃ , Al ₂ O ₃ , ZrO ₂ , (NH ₄ ) H ₂ (PO ₄ ) ₃ , SiO _{2 and the} like. . In accordance with a general procedure for producing ceramics by sintering, the raw materials are thoroughly mixed and pulverized using a ball mill or the like.

  Next, the mixed raw materials are calcined in the atmosphere, for example. The calcination may be performed in one stage, or may be performed in two or more stages at different temperatures. For example, when calcining in two stages, calcining is performed at 300 ° C. for 2 hours and 700 ° C. for 2 hours.

  Then, the obtained calcined body is pulverized with a ball mill or the like. An organic binder and, if necessary, a solvent and a plasticizer are added to the obtained powder to obtain a raw material slurry for the electrolyte layer.

  Also, a metal paste is prepared. For example, a commercially available metal paste may be used, and an organic binder, a solvent, a plasticizer, etc. may be added to Ag powder and a metal paste may be produced.

  The powder after calcining for the electrolyte layer and the powder of the metal material are weighed at a predetermined ratio, added with a solvent, and then mixed using a ball mill or the like. An organic binder and, if necessary, a solvent and a plasticizer are added to the obtained powder to obtain a raw material slurry for the interface composite layer.

  Next, as shown in FIG. 2A, for example, a resin film 20 such as a PET film is prepared. First, a first metal paste layer 2 ′ is formed on the resin film 20 by a doctor blade method or the like. Similarly, a second metal paste layer 3 ′ is formed on the resin film 20. As shown in FIG. 2 (b), the first interface composite layer molded body 32 ′ and the second interface composite layer molded body 33 ′ are formed on the resin film 20 by a screen printing method, a doctor blade method, or the like. Form. Further, as shown in FIG. 2C, an electrolyte layer green sheet 1 ′ is formed on the resin film 30.

The first metal paste layer 2 ', the second metal paste layer 3', the first interface composite layer molded body 32 ', the second interface composite layer molded body 33', and the electrolyte layer green sheet 1 'are dried. Then, these are peeled off from the resin film, and as shown in FIG. 2 (d), the second metal paste layer 3 ′, the second interface composite layer molded body 33 ′, the electrolyte layer green sheet 1 ′, These are laminated | stacked in order of 1st interface composite-layer molded object 32 'and 1st metal paste layer 2', and the green sheet laminated body 21 is obtained. This is pressurized and pressure-bonded at 85 ° C. and 200 kg / cm ² .

  The size of the first metal paste layer 2 ′, the second metal paste layer 3 ′, the first interface composite layer molded body 32 ′, the second interface composite layer molded body 33 ′ and the electrolyte layer green sheet 1 ′ The thickness is determined in consideration of shrinkage due to sintering based on the thickness and size of the electrolyte layer 1, the first electrode layer 2, and the second electrode layer 3 after sintering.

  Thereafter, as shown in FIG. 2 (d), the resin film 20 is peeled from the green sheet laminate 21, and the green sheet laminate 21 is sintered. The sintering temperature is 850 ° C. or higher and 1200 ° C. or lower. The sintering time is, for example, 1 minute or more and 24 hours or less. Moreover, sintering can be performed in air | atmosphere, for example in the case of Ag.

  By sintering, the first metal paste layer 2 ′, the second metal paste layer 3 ′, the first interface composite layer molded body 32 ′, the second interface composite layer molded body 33 ′, and the electrolyte layer green sheet 1 'From which volatile components such as organic binders and solvents are removed. Further, the respective layers are sintered, and as shown in FIG. 2 (e), the first and second layers made of the metal material contained in the first metal paste layer 2 ′ and the second metal paste layer 3 ′. Electrode layers 2 and 3, electrolyte layer 1 having a composition represented by the above composition formula (1) and including a solid electrolyte material made of ceramics having a NASICON type crystal structure, and a first and a second including a solid electrolyte and a metal material A co-sintered body 7 including the second interface composite layers 32 and 33 is obtained.

  Thereafter, the lead electrode 5 is connected to the first and second electrode layers 2 and 3 using the solder 4 and the entire co-sintered body 7 is covered with the resin mold 6 to complete the solid ion capacitor 11. .

(Multilayer capacitor)
An embodiment of a multilayer capacitor will be described. FIG. 3 schematically shows a cross-sectional structure of the solid ion capacitor 12 of the present embodiment. The solid ion capacitor 12 includes a plurality of electrolyte layers 1, a plurality of first electrode layers 2, a plurality of second electrode layers 3, a plurality of first interface composite layers 32, and a plurality of second interface composite layers 33. Prepare. These layers are stacked, and the first electrode layers 2 and the second electrode layers 3 are alternately positioned in the stacking direction. Further, each electrolyte layer 1 is located between the first electrode layer 2 and the second electrode layer 3. Each first interface composite layer 32 is located between the first electrode layer 2 and the electrolyte layer 1, and each second interface composite layer is provided between the second electrode layer 3 and the electrolyte layer 1. Layer 33 is located. The plurality of electrolyte layers 1, the plurality of first electrode layers 2, the plurality of second electrode layers 3, the plurality of first interface composite layers 32, and the plurality of second interface composite layers 33 are co-sintered bodies 7. Is configured. In the present embodiment, the solid ion capacitor 12 includes the first interface composite layer 32 and the second interface composite layer 33, but may include only one of them.

  As described with reference to FIG. 1, each first interface composite layer 32 and each second interface composite layer 33 include a metal material 34 and a solid electrolyte material 35, and each of the first interface composite layers 32 and 33. The interface composite layer 32 and the second interface composite layer 33 have the same structure.

  The co-sintered body 7 has side surfaces 7a and 7b positioned on opposite sides, and the end surfaces of the plurality of first electrode layers 2 are exposed on the side surface 7a. Similarly, the end surfaces of the plurality of second electrode layers 3 are exposed on the side surface 7b.

  The solid ion capacitor 12 further includes a first external electrode 8 and a second external electrode 9. The first external electrode 8 is provided on the side surface 7 a and is electrically connected to the plurality of first electrode layers 2. It is connected to the. Similarly, the second external electrode 9 is provided on the side surface 7 b and is electrically connected to the plurality of second electrode layers 3.

  In the solid ion capacitor 12, the plurality of electrolyte layers 1, the plurality of first electrode layers 2, the plurality of second electrode layers 3, the plurality of first interface composite layers 32, and the second interface composite layers 33 are solid. The electrolyte layer 1, the first and second electrode layers 2 and 3, and the first and second interface composite layers 32 and 33 of the ion capacitor 11 are made of the same material. As described above, since the plurality of first electrode layers 2 and the plurality of second electrode layers 3 formed therein can be co-sintered with the plurality of electrolyte layers 1, the multilayer capacitor is similar to the conventional LTCC. It can be manufactured using a process. In addition, since the solid ion capacitor 12 includes the plurality of first interface composite layers 32 and the plurality of second interface composite layers 33, the solid ion capacitor 12 includes the first interface composite layer 32 and the second interface composite layer 33. It has a large capacity compared to the case without it.

  Next, a method for manufacturing the solid ion capacitor 12 will be described with reference to FIG.

  First, as in the case of the solid ion capacitor 11, a raw material slurry for the electrolyte layer, a metal paste, and a raw material slurry for the interface composite layer are prepared.

  As shown in FIG. 4A, for example, a resin film 20 such as a PET film is prepared. First, a green sheet 1 ′ of an electrolyte layer is formed on the resin film 20 by a doctor blade method or the like. The size and thickness of the green sheet 1 ′ of the electrolyte layer are determined in consideration of shrinkage due to sintering based on the thickness and size of the electrolyte layer 1 after sintering. As shown in FIG. 4B, separately, a green sheet 1 ′ of the electrolyte layer is formed on the resin film 20 by a doctor blade method or the like, and on the green sheet 1 ′ of the electrolyte layer by a screen printing method. A second interface composite layer molded body 33 ′, a second metal paste layer 3 ′, and a second interface composite layer molded body 33 ′ are formed.

  On the green sheet 1 ′ of the electrolyte layer formed in FIG. 4 (a), the laminate prepared in FIG. 4 (b) is placed so that the second interface composite layer 33 ′ is in contact with the green sheet 1 ′ of the electrolyte layer. In addition, the resin film 20 is peeled off while being superimposed on the green sheet 1 ′ of the electrolyte layer while aligning. At this time, in order to prevent displacement and peeling, the pressure may be weakly applied.

Thereafter, the laminate shown in FIG. 4B is produced in the same procedure, and the produced laminate is repeated a predetermined number of times. Thereby, the green sheet laminated body 21 shown in FIG.4 (c) is obtained. This is pressed and pressure-bonded at 85 ° C. and 200 kg / cm ² , for example.

  Thereafter, as shown in FIG. 4 (d), the resin film 20 is peeled from the green sheet laminate 21, and the green sheet laminate is sintered. The sintering temperature is 850 ° C. or higher and 950 ° C. or lower. The sintering time is, for example, 1 minute or more and 24 hours or less. Moreover, sintering can be performed in air | atmosphere, for example in Ag.

  By sintering, a plurality of first metal paste layers 2 ′, a plurality of second metal paste layers 3 ′, a plurality of first interface composite layer molded bodies 32 ′, and a plurality of second interface composite layer molded bodies 33 ′. And volatile components, such as an organic binder and a solvent, are removed from the green sheet 1 'of a plurality of electrolyte layers. Each layer is sintered, and as shown in FIG. 4 (d), a plurality of first electrodes made of a metal material contained in the first metal paste layer 2 ′ and the second metal paste layer 3 ′. A plurality of electrolyte layers 1 including a layer 2 and a plurality of second electrode layers 3, a solid electrolyte material having a composition represented by the above composition formula (1) and made of ceramics having a NASICON crystal structure, and a solid electrolyte And the co-sintered body 7 containing the 1st and 2nd interface composite layers 32 and 33 containing a metal material is obtained.

  Thereafter, the first and second external electrodes 8 and 9 are respectively formed on the side surfaces 7a and 7b of the co-sintered body 7, thereby completing the solid ion capacitor 12.

(Example)
(1) Production of Solid Ion Capacitor, Measurement of Electrical Characteristics, and Confirmation of Cross Section Structure Hereinafter, ceramics used in the solid ion capacitor of this embodiment will be produced, and the results of examining various characteristics will be described.

As raw materials, Na ₂ CO ₃ , Al ₂ O ₃ , ZrO ₂ , SiO ₂ , ammonium phosphate (NH ₄ ) ₂ H (PO ₄ ) ₃ powder was prepared, and Na _3.2 (A _0.1 Zr _0.9 ) ₂ ( P _1-x Si _x O ₄ ) ₃ , and weighed so that the composition ratio was x = 0.1.

  Raw materials weighed with ethanol and zirconia balls were put into a ball mill container, and mixed by ball mill at 100 rpm for 20 hours. The mixed raw material was taken out, dried, put into a Teflon (registered trademark) container, and heated in air at 300 ° C. for 2 hours to perform primary calcining. The primary calcined raw material was taken out from the Teflon (registered trademark) container, dried, put into an alumina container, and heated in the atmosphere at 700 ° C. for 2 hours to perform secondary calcining.

  Next, after the secondary calcined raw material was crushed with a mortar, it was pulverized and mixed with a ball mill. The calcined raw material pulverized from the ball mill was taken out, dried and passed through a 500 μm mesh. This is the electrolyte layer powder.

  The electrolyte layer powder and the pure Ag powder having a particle diameter of 2 μm are weighed so that the volume ratio is 1: 1 (Ag powder is 50% with respect to the total volume of the electrolyte layer powder and the pure Ag powder), and the ethanol medium is added. For 20 hours. The mixture was taken out from the ball mill, dried, and passed through a 500 μm mesh. This powder was used as an interface composite layer powder.

  The electrolyte layer powder, the interface composite layer powder, and the pure Ag powder were mixed with ethanol, PVB, and a plasticizer, respectively, to prepare an electrolyte layer slurry, an interface composite layer slurry, and an electrode layer slurry, respectively. The powder and organic material at this time were weighed at a weight ratio of 5: 4.

  Next, these slurries were applied onto a PET film, and an electrolyte green sheet having a thickness of 0.1 mm, a green sheet having an interface composite layer having a thickness of 0.03 mm, and a green sheet having an electrode layer having a thickness of 0.04 mm were formed. Produced. Thereafter, these green sheets were dried.

  Three green sheets of the electrolyte layer were punched into a circle having a diameter of 14 mm, and three sheets were stacked. Each of the green sheet of the interface composite layer and the green sheet of the electrode layer was punched into a circle having a diameter of 14 mm and a diameter of 6 mm. The green sheet of the interface composite layer and the electrode layer having a diameter of 14 mm are arranged on one side of the green sheet of the electrolyte layer, and the green sheet of the interface composite layer and the electrode layer of 6 mm in diameter are arranged on the other side. A green sheet laminate was obtained. The laminated body is press-welded at 85 ° C., and thereafter. It heated at the temperature increase rate of 200 degreeC / Hr, and sintered at 900 degreeC in air | atmosphere for 2 hours. The obtained sample is called the solid ion capacitor of the example.

  The characteristics of the solid ion capacitor of the example were measured. The frequency was swept with an impedance meter, Z-θ measurement of the solid ion capacitor of the example was performed, and the capacity was obtained. Further, the cross section was CP processed and observed by SEM.

  For comparison, a capacitor having no interface composite layer was also produced. The obtained sample is called a comparative solid ion capacitor. For the solid ion capacitor of the comparative example, the Z-θ measurement was performed in the same manner to obtain the capacity.

  FIG. 5 shows the frequency characteristics of the capacitance. As shown in FIG. 5, the frequency characteristics of the capacitance are almost the same, but a larger capacitance is obtained in the embodiment. This is presumably because the interfacial composite layer expands the electrode area and increases the capacity.

  6A shows a cross section of the entire co-sintered body portion of the solid ion capacitor of the example, and FIG. 6B shows an enlarged cross section of the electrolyte layer (electrolyte layer 1) portion. (C) shows a cross section of the electrode layer (first electrode layer 2, second electrode layer 3) and interface composite layer portion, and (d) shows the interface composite layer (first interface composite layer 32, second interface layer). The cross section which expanded further the interface composite layer 33 part part is shown.

  From FIG. 6A, the electrode layer, the electrolyte layer, and the interface composite layer constitute an integral co-sintered body, and the metal material does not react with the solid electrolyte material or disappear due to the reaction. I understood that. FIG. 6B shows that the electrolyte layer is composed of a dense sintered body. Also, from FIGS. 6A and 6C, there is no cavity at the interface between the electrode layer and the interface composite layer and the interface between the electrolyte layer and the interface composite layer, and the adhesion at these interfaces is good. I understood that. Further, from FIG. 6 (d), it was found that the metal material and the solid electrolyte material are intricately distributed in the interface composite layer.

(2) Examination of interfacial composite layer In order to examine the mixing ratio in the interfacial composite layer, the electrolyte layer powder and pure Ag powder having a particle size of 2 μm were mixed at a volume ratio of 8: 2, 7: 3, 5: 5 (electrolyte layer powder and The Ag powder was weighed at a ratio of 20%, 30%, and 50%) with respect to the total volume of the pure Ag powder, mixed, press-molded, and sintered at 900 ° C. When the electrical resistance of the obtained sintered body was measured, the sintered body having a mixing ratio of 8: 2 had electronic insulation, but the other sintered bodies were conductors. Therefore, if the ratio of the metal material in the interface composite layer is 30% or more in terms of the total volume of the metal material and the solid electrolyte material, the metal material may be connected in the interface composite layer and have electronic conductivity. I understood. Further, from this result, when the mixing ratio of the metal material to the electrolyte material is larger than 7: 3, that is, when the ratio of the metal material exceeds 70% in the total volume of the metal material and the solid electrolyte material, the solid It has been found that there is a possibility that the electrolyte material is not connected and the solid electrolyte material is isolated in the interface composite layer. From this, it was found that the ratio of the metal material in the interface composite layer is preferably 30% or more and 70% or less in terms of the total volume of the metal material and the solid electrolyte material.

(3) Summary From this example, it was found that the capacity of the solid ion capacitor can be increased by providing the interface composite layer. It was also found that the adhesion between the electrode layer and the electrolyte layer can be improved by providing the interface composite layer.

  Furthermore, it was found that the electrode layer, the electrolyte layer, and the interface composite layer constitute an integral co-sintered body, and the metal material did not react with the solid electrolyte material or disappear due to the reaction.

  Therefore, from this example, it was confirmed that a solid ion capacitor using Na as a ceramic material having a NASICON crystal structure as an electrolyte material could be realized.

  The present invention can be suitably used for a capacitor having a large capacity that can be used in various applications.

1 'green sheet of electrolyte layer 1 electrolyte layer 2' first metal paste layer 2 first electrode layer 3 'second metal paste layer 3 second electrode layer 4 solder 5 lead electrode 6 resin mold 7 co-sintering Body 7a, 7b Side surface 8 First external electrode 9 Second external electrode 11, 12 Solid ion capacitor 13 Electrolyte layer 20 Resin film 21 Green sheet laminate 32 First interface composite layer 33 Second interface composite layer 32 ′ First interface composite layer molded body 33 ′ Second interface composite layer molded body 34 Metal material 35 Solid electrolyte material

Claims (7)

A first electrode layer and a second electrode layer made of a metal material containing Ag;
An electrolyte layer made of a solid electrolyte material made of ceramic containing Na, and located between the first and second electrode layers;
The metal material and the solid electrolyte material that are intricately distributed to each other, and at least one of the first electrode layer and the electrolyte layer, and the second electrode layer and the electrolyte layer An interfacial composite layer provided in
A solid ion capacitor in which the first or second electrode layer and the metal material of the interface composite layer are electrically connected.   2. The solid ion capacitor according to claim 1, wherein the electrolyte layer, the first and second electrode layers, and the interface composite layer constitute a co-sintered body.   3. The solid ion capacitor according to claim 1, wherein the interface composite layer includes the metal material in a ratio of 30% to 70% with respect to a total volume of the metal material and the solid electrolyte material. . The ceramics are
_{Na 1 + x + y (Al} y Zr 2-y) (Si x P 3-x) O 12,
0 ≦ x ≦ 2, 0 <y ≦ 0.4
The solid ion capacitor according to claim 1, having a composition represented by: Each of the electrolyte layer, the interface composite layer, the first electrode layer, and the second electrode layer includes a plurality of the electrolyte layer, the interface composite layer, the first electrode layer, and the second electrode layer. The second electrode layer is laminated,
The first electrode layer and the second electrode layer are alternately positioned in the stacking direction,
The electrolyte layer is located between the first electrode layer and the second electrode layer;
The interfacial composite layer is provided between the first electrode layer and the electrolyte layer and between the second electrode layer and the electrolyte layer, respectively. The solid ion capacitor described. A pair of metal paste layers; an electrolyte layer green sheet positioned between the pair of metal paste layers; one of the pair of metal paste layers and between the electrolyte layer green sheets and the pair of metal paste layers. Forming a green sheet laminate including an interfacial composite layer green sheet positioned between at least one of the other and the electrolyte layer green sheet;
Including co-sintering the pair of metal paste layers, the electrolyte layer green sheet, and the interfacial composite layer green sheet by holding the green sheet laminate at a temperature of 850 ° C. to 1000 ° C. And
The metal paste includes Ag,
The method for producing a solid ion capacitor, wherein the green sheet for electrolyte includes Na as a main component material of ceramics. The green sheet electrolyte layer, as materials of the main component of the ceramic, Na, Al, Zr, P, and Si, after sintering,
_{Na 1 + x + y (Al} y Zr 2-y) (Si x P 3-x) O 12,
0 ≦ x ≦ 2, 0 <y ≦ 0.4
The manufacturing method of the solid ion capacitor of Claim 6 included by the composition ratio represented by these.