JP2019087348A - All-solid battery - Google Patents

Abstract

To provide an all-solid battery in which the mutual diffusion of a solid electrolyte layer and a cover layer during burning can be suppressed and unexpected battery reaction through the cover layer can be suppressed.SOLUTION: An all-solid battery comprises: a solid electrolyte layer; a positive electrode layer formed on one face of the solid electrolyte layer; a negative electrode layer formed on the other face of the solid electrolyte layer; a first cover layer laminated on a first outermost layer in a lamination direction in a laminate structure including the solid electrolyte layer, the positive electrode layer and the negative electrode layer; and a second cover layer laminated on a second outermost layer on a side opposite to the first outermost layer in the laminate structure. The first and second cover layers include, as a primary component, a solid electrolyte lower in ion conductivity than the solid electrolyte layer.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an all solid state battery.

  In recent years, secondary batteries are used in various fields. The secondary battery using the electrolytic solution has problems such as leakage of the electrolytic solution. Then, development of the all-solid-state battery which was equipped with the solid electrolyte and also comprised the other component by solid is performed. Moreover, in order to improve the capacity density, it is desired to make the battery unit multi-layered. The art which provides a cover layer in the upper and lower sides of the lamination direction of all the solid batteries at the time of multi-layering is indicated (for example, refer to patent documents 1-4).

JP 2007-80812 A JP, 2011-198692, A JP 2008-198402 A JP, 2016-207540, A

  The cover layer is preferably made of a material that does not interdiffuse during firing with the solid electrolyte layer. Therefore, it is conceivable to use a material having the same composition as the solid electrolyte layer as the cover layer. However, when a plurality of all the solid batteries described above are stacked to constitute a battery module, there is a possibility that an unexpected battery reaction may occur through the cover layer due to ion conduction in the cover layer.

  The present invention has been made in view of the above problems, and provides an all-solid battery in which mutual diffusion between the solid electrolyte layer and the cover layer at the time of firing is suppressed and unexpected battery reaction via the cover layer is suppressed. The purpose is

  The all solid battery according to the present invention comprises a solid electrolyte layer, a positive electrode layer formed on one surface of the solid electrolyte layer, a negative electrode layer formed on the other surface of the solid electrolyte layer, and the solid layer. A first cover layer laminated on a first outermost layer in a lamination direction in the laminated structure including the electrolyte layer, the positive electrode layer, and the negative electrode layer; and a second cover layer opposite to the first outermost layer in the laminated structure And a second cover layer laminated on the outermost layer, wherein the first cover layer and the second cover layer are mainly composed of a solid electrolyte whose ion conductivity is lower than that of the solid electrolyte layer. Do.

  In the all solid battery, the solid electrolyte layer may be mainly composed of a solid electrolyte of NASICON type crystal structure.

  In the all solid state battery, the total ion conductivity of the first cover layer and the second cover layer may be two digits or more lower than the total ion conductivity of the solid electrolyte layer at the same temperature.

  In the all solid battery, the first cover layer and the second cover layer may contain as a main component a solid electrolyte in which a ratio of Zr is larger than that of the main component solid electrolyte of the solid electrolyte layer.

  According to the present invention, it is possible to provide an all-solid battery in which mutual diffusion at the time of firing between the solid electrolyte layer and the cover layer is suppressed, and an unexpected battery reaction via the cover layer is suppressed.

It is a typical sectional view of the all-solid-state battery concerning an embodiment. It is an exploded view showing the layered structure of an anode and a cathode. It is a typical sectional view of the all-solid-state battery concerning an embodiment. It is an exploded view showing the layered structure of an anode and a cathode. (A)-(c) is a figure which illustrates a battery module. It is a figure which illustrates the synthetic | combination ionic conductivity of LAZP. It is a figure which illustrates the synthetic | combination ionic conductivity of LAGP. It is a figure which illustrates the flow of the manufacturing method of an all-solid-state battery.

  Hereinafter, embodiments will be described with reference to the drawings.

(Embodiment)
FIG. 1 is a schematic cross-sectional view of an all-solid battery 100 according to an embodiment. FIG. 2 is an exploded view showing a laminated structure of a positive electrode 20 and a negative electrode 40 described later. FIG. 1 corresponds to a cross section taken along line A-A of FIG. In addition, in FIG. 2, the solid electrolyte layer 30 mentioned later is abbreviate | omitted.

  All solid battery 100 has a substantially rectangular parallelepiped shape. As illustrated in FIG. 1, in the all-solid battery 100, the first stacked unit in which the solid electrolyte layer 30 is stacked on the positive electrode 20 on the first cover layer 10, and the solid electrolyte layer 30 on the negative electrode 40. And the second stacked units, which are alternately stacked. In the case where the uppermost lamination unit is the first lamination unit, the negative electrode 40 and the second cover layer 50 are laminated in this order on the uppermost first lamination unit. When the uppermost lamination unit is the second lamination unit, the positive electrode 20 and the second cover layer 50 are laminated in this order on the uppermost second lamination unit. Each solid electrolyte layer 30 has substantially the same shape. Adjacent two solid electrolyte layers 30 face each other with the positive electrode 20 or the negative electrode 40 interposed therebetween.

  As illustrated in FIGS. 1 and 2, in the first stacked unit, the positive electrode 20 reaches the first edge 25 which is a part of one end face of the solid electrolyte layer 30 on the lower surface of the solid electrolyte layer 30. There is. On the lower surface of the solid electrolyte layer 30, a first blank layer 60 having substantially the same thickness as that of the positive electrode 20 is provided in a peripheral portion where the positive electrode 20 is not provided.

  In the second stacked unit, the negative electrode 40 partially reaches the second edge 45 which is the other end face of the solid electrolyte layer 30 on the lower surface of the solid electrolyte layer 30. Both end surfaces of the solid electrolyte layer 30 have a positional relationship in which they face each other. On the lower surface of the solid electrolyte layer 30, a second blank layer 70 having substantially the same thickness as that of the negative electrode 40 is provided in a peripheral portion where the negative electrode 40 is not provided.

  The positive electrode 20 includes a positive electrode layer 21 and a current collector layer 22. As an example, the positive electrode 20 has a structure in which the current collector layer 22 is sandwiched between two positive electrode layers 21. At the first edge, a first external electrode 80 connected to each current collector layer 22 is provided. The negative electrode 40 includes a negative electrode layer 41 and a current collector layer 42. As an example, the negative electrode 40 has a structure in which the current collector layer 42 is sandwiched by two negative electrode layers 41. At the second edge, a second external electrode 90 connected to each current collector layer 42 is provided. The thickness of each layer is not particularly limited. However, if the electrode layer is too thin, the capacity density may be difficult to increase. If the electrode layer is too thick, the response (output characteristics) of the all solid battery 100 may be reduced. Therefore, the layer thickness of the positive electrode layer 21 and the negative electrode layer 41 is preferably 1 μm to 100 μm, and more preferably 2 μm to 50 μm. If the current collector layer is too thin, the continuity of the current collector may be reduced, that is, the effective area of the all-solid battery 100 may be reduced. Since the current collector layer itself is a portion that does not contribute to the battery capacity, if the current collector layer is too thick, the capacity density may be reduced. Therefore, the layer thickness of the current collector layer 22 and the current collector layer 42 is preferably 0.1 μm to 5 μm, and more preferably 1 μm to 3 μm.

  The cross section of FIG. 1 is a cross section passing through a portion where the positive electrode 20 reaches the first edge 25 and a portion where the negative electrode 40 reaches the second edge 45. Therefore, in the stacking direction of FIG. 1, the negative electrode 40 is interposed between the first blank layer 60 and the other first blank layer 60. Further, in the stacking direction of FIG. 1, the positive electrode 20 is interposed between the second blank layer 70 and the other second blank layer 70.

  FIG. 3 is a schematic cross-sectional view of the all-solid battery 100. FIG. 4 is an exploded view showing a laminated structure of the positive electrode 20 and the negative electrode 40. FIG. 3 corresponds to a cross section taken along line B-B of FIG. The B-B line cross section does not pass through a portion where the positive electrode 20 reaches the first edge 25 and a portion where the negative electrode 40 reaches the second edge 45. Therefore, not the negative electrode 40 but the second blank layer 70 intervenes between the first blank layer 60 and the other first blank layer 60 in the stacking direction of FIG. 3. Further, in the stacking direction of FIG. 3, the first blank layer 60 rather than the positive electrode 20 intervenes between the second blank layer 70 and the other second blank layer 70.

  The battery module including the all-solid battery 100 has a configuration in which a plurality of all-solid batteries 100 are connected in parallel. For example, as illustrated in FIG. 5A, the first cover layer 10 of the second all-solid-state battery 100 is opposed to the second cover layer 50 of the first all-solid-state battery 100. All-solid battery 100 and second all-solid battery 100 are stacked. In addition, as illustrated in FIG. 5B, the second external electrode 90 of the first all-solid battery 100 and the second external electrode 90 of the second all-solid battery 100 are flush with each other. One all-solid battery 100 and the second all-solid battery 100 are stacked. The first external electrode 80 of the first all solid state battery 100 and the first external electrode 80 of the second all solid state battery 100 are connected, and the second external electrode 90 of the first all solid state battery 100 and the second all solid state battery 100 By connecting the second external electrode 90 of the solid battery, the first all solid battery 100 and the second all solid battery 100 can be connected in parallel.

  A similar stack may be further stacked on the stack of the first all-solid battery 100 and the second all-solid battery 100. In addition, by connecting the second external electrode 90 of another all-solid battery 100 to the first external electrode 80, two all-solid batteries 100 can be connected in series.

  In the present embodiment, as illustrated in FIG. 5C, as an example, the battery module 200 connects a pair of all solid batteries 100 in series and connects eight pairs of all solid batteries 100 in parallel. It has a structure that These all-solid-state batteries 100 are accommodated, for example, in an outer can 300.

The solid electrolyte layer 30 is not particularly limited as long as it is an oxide-based solid electrolyte, and, for example, mainly contains an oxide-based solid electrolyte having a NASICON structure. An oxide-based solid electrolyte having a NASICON structure has high ionic conductivity and has the property of being stable in the atmosphere. The oxide-based solid electrolyte having the NASICON structure is, for example, a lithium-containing phosphate or the like. The phosphate is not particularly limited, for example, a composite lithium phosphate salts with Ti _{(e.g., Li 1 + x Al x Ti} 2-x (PO 4) 3) , and the like. Hereinafter, Li _{1 + x} Al _x Ti _2-x (PO ₄ ) ₃ may be referred to as LATP. Alternatively, Ti can be partially or totally substituted with a tetravalent transition metal such as Ge, Sn, Hf, Zr or the like. Further, in order to increase the Li content, trivalent transition metals such as Al, Ga, In, Y, La may be partially substituted. Phosphate having the NASICON structure comprises lithium, more specifically, for example, Li-Al-Ge-PO-based material _{(Li 1 + x Al x Ge} 2-x (PO 4) 3) and, Li- Al-Zr-PO-based material _{(Li 1 + x Al x Zr} 2-x (PO 4) 3) or, Li-Al-Ti-PO-based material _{(Li 1 + x Al x Ti} 2-x (PO 4) ₃ ) etc. Hereinafter, Li _{1 + x} Al _x Ge _2-x (PO ₄ ) ₃ may be referred to as LAGP, and Li _{1 + x} Al _x Zr _2-x (PO ₄ ) ₃ may be referred to as LAZP. For example, it is preferable to use an LAGP-based material in which the same transition metal as the transition metal contained in the phosphate having an olivine-type crystal structure contained in the positive electrode layer 21 and the negative electrode layer 41 is added in advance. For example, when the positive electrode layer 21 and the negative electrode layer 41 contain a phosphate containing Co and Li, it is preferable that the solid electrolyte layer 30 contain a LAGP-based material to which Co has been added in advance. In this case, the effect of suppressing the elution of the transition metal contained in the electrode active material into the electrolyte can be obtained.

  The positive electrode layer 21 contains a substance having an olivine type crystal structure as an electrode active material. The negative electrode layer 41 also preferably contains the electrode active material. As such an electrode active material, a phosphate containing a transition metal and lithium can be mentioned. The olivine-type crystal structure is a crystal possessed by natural olivine and can be distinguished by X-ray diffraction.

As a typical example of an electrode active material having an olivine type crystal structure, LiCoPO ₄ containing Co, or the like can be used. It is also possible to use a phosphate or the like in which the transition metal Co is replaced in the above chemical formula. Here, the ratio of Li or PO ₄ may vary depending on the valence. It is preferable to use Co, Mn, Fe, Ni or the like as the transition metal.

  The electrode active material having an olivine type crystal structure acts as a positive electrode active material in the positive electrode layer 21. For example, when an electrode active material having an olivine type crystal structure is contained only in the positive electrode layer 21, the electrode active material acts as a positive electrode active material. In the case where the negative electrode layer 41 also contains an electrode active material having an olivine crystal structure, in the negative electrode layer 41, although its mechanism of action is not completely understood, partial solid solution with the negative electrode active material is made. The effects of an increase in the discharge capacity and an increase in the operating potential due to the discharge, which are presumed to be based on the formation of a state, are exerted.

  When both the positive electrode layer 21 and the negative electrode layer 41 contain an electrode active material having an olivine type crystal structure, transition metals which may be identical to or different from each other are preferably used in the respective electrode active materials. included. That "the same or different may be used" means that the electrode active materials contained in the positive electrode layer 21 and the negative electrode layer 41 may contain the same kind of transition metal, or different kinds of transition metals are mutually different. It may be included. The positive electrode layer 21 and the negative electrode layer 41 may contain only one type of transition metal, or may contain two or more types of transition metals. Preferably, the positive electrode layer 21 and the negative electrode layer 41 contain the same kind of transition metal. More preferably, the electrode active materials contained in both electrode layers have the same chemical composition. By including the same kind of transition metal in the positive electrode layer 21 and the negative electrode layer 41 or containing the electrode active material of the same composition, the similarity of the composition of the both electrode layers is enhanced, and thus the terminals of the all solid battery Even if the mounting of the sensor is reversed, depending on the application, it has the effect of being able to withstand actual use without malfunction.

  Of the positive electrode layer 21 and the negative electrode layer 41, the negative electrode layer 41 may further contain a material known as a negative electrode active material. By containing the negative electrode active material only in one of the electrolytic layers, it becomes clear that the one electrode layer acts as a negative electrode and the other electrode layer acts as a positive electrode. When the negative electrode active material is contained in only one electrode layer, the one electrode layer is preferably the negative electrode layer 41. A material known as a negative electrode active material may be contained in both of the electrolytic layers. With regard to the negative electrode active material of the electrode, the prior art in secondary batteries can be appropriately referred to. For example, compounds such as titanium oxide, lithium titanium composite oxide, carbon, lithium titanium composite phosphate, lithium vanadium phosphate and the like Can be mentioned.

  In the preparation of the positive electrode layer 21 and the negative electrode layer 41, in addition to these active materials, an oxide-based solid electrolyte material or a conductive material (conductive aid) such as carbon or metal may be further added. With regard to these members, the electrode layer paste can be obtained by uniformly dispersing the binder and the plasticizer in water or an organic solvent. As a metal of a conductive support agent, Pd, Ni, Cu, Fe, the alloy containing these, etc. are mentioned.

  A conductive material such as carbon or metal can also be applied to the current collector layers 22 and 42. As the conductive metal, a simple substance, an alloy or an oxide of a metal such as Ni, Cu, Pd, Ag, Pt, Au, Al or Fe can be used.

  In order to suppress the composition change of the solid electrolyte layer 30, it is preferable that the first cover layer 10 and the second cover layer 50 do not interdiffuse with the solid electrolyte layer 30 at the time of firing. Therefore, it is conceivable to make the first cover layer 10 and the second cover layer 50 close in composition to the solid electrolyte layer 30. So, in this embodiment, the 1st cover layer 10 and the 2nd cover layer 50 have an oxide system solid electrolyte as a main component.

  However, when the first cover layer 10 and the second cover layer 50 contain an oxide-based solid electrolyte as the main component, the ion conductivity of the first cover layer 10 and the second cover layer 50 may be increased. When the ion conductivity of the first cover layer 10 and the second cover layer 50 is high, ion conduction occurs in the first cover layer 10 and the second cover layer 50. In this case, for example, in the battery module 200 illustrated in FIGS. 5A to 5C, between the positive electrode 20 and the negative electrode 40, with the opposing first cover layer 10 and second cover layer 50 interposed therebetween. May cause an unexpected battery reaction. In the case of stacking a plurality of all solid batteries 100 as in the battery module 200 in particular, the first cover layer 10 and the second cover layer 50 are formed as thin as possible (for example, 30 μm or less in thickness) to improve capacity density. In order to reduce the gap between all the solid batteries, an unexpected battery reaction is likely to occur. Therefore, in the present embodiment, the first cover layer 10 and the second cover layer 50 have lower ion conductivity than the solid electrolyte layer 30.

  According to this configuration, it is possible to suppress an unexpected cell reaction while suppressing mutual diffusion at the time of firing between the first cover layer 10 and the second cover layer 50, and the solid electrolyte layer 30. The level of ion conductivity is determined by comparing the total ion conductivity, which is the conductivity calculated from the total resistance value of the bulk resistance and the grain boundary resistance measured by the alternating current impedance method, at the same temperature. Do.

  Subsequently, specific material compositions of the first cover layer 10 and the second cover layer 50 will be described. When the solid electrolyte layer 30 has a NASICON-type Li-X-Y-P-O composition, the first cover layer 10 and the second cover layer 50 may also be NASICON-type Li-X-Y-. It is preferable to have a PO composition. The X site is a trivalent metal element such as Al or Ga. Y site is a transition metal such as Ti, Ge, Zr and the like. For example, by setting the composition ratio of Zr in the first cover layer 10 and the second cover layer 50 higher than the composition ratio of Zr in the solid electrolyte layer 30, the ion conductivity of the first cover layer 10 and the second cover layer 50 can be obtained. It is preferable to lower the sex. For example, in the solid electrolyte layer 30, the ratio occupied by Zr among transition metals entering the Y site is preferably 50% or less, more preferably 30% or less, and still more preferably 10% or less. Also, for example, in the first cover layer 10 and the second cover layer 50, 50% or more is preferable, 70% or more is more preferable, and 90% or more in the ratio of Zr occupied in the transition metal entering the Y site. It is further preferred that

The solid electrolyte layer 30 can also be applied to a solid electrolyte having a ZrICON-containing NASICON-type crystal structure, but in the low ion conductive phase Li-Zr-PO (for example, triclinic structure), the internal resistance of the battery Is not preferable because the Therefore, it is preferable that a large amount of Li-Zr-P-O having a rhombohedral crystal structure is contained. On the other hand, for the solid electrolyte applied to the first cover layer 10 and the second cover layer 50, it is preferable to mainly use Li-Zr-P-O, which is a low ion conductive phase, and there is a concern that an unexpected battery reaction may occur. Li-Zr-P-O in the ion conducting phase (rhombohedral structure) is less preferred. Hereinafter, Li-Zr-P-O may be referred to as LZP. The structure is not particularly limited as long as it has the above structure, but, for example, when the solid electrolyte applied to the solid electrolyte layer 30 is LAGP (Li _1.5 Al _0.5 Ge _1.5 (PO ₄ ) ₃ ), From the viewpoint of suppressing mutual diffusion, the solid electrolyte applied to the first blank layer 60 and the second blank layer 70 is also preferably LAZP (Li _1.5 Al _0.5 Zr _1.5 (PO ₄ ) ₃ ) of the same composition.

Here, the definition of high ion conduction and low ion conduction in the ion conductor will be discussed. High ion conductivity can be defined, for example, as a total ion conductivity at room temperature of 1 × 10 ⁻⁵ S / cm or more. Low ion conductivity can be defined, for example, as an overall ionic conductivity at room temperature of less than 1 × 10 ⁻⁶ S / cm. Thus, there is a difference of more than an order of magnitude between high and low ion conduction in the ion conductor. In the present embodiment, the integrated ionic conductivity of the first cover layer 10 and the second cover layer 50 does not have to function as an ion conductor, so that the integrated ion conductivity of the first cover layer 10 and the second cover layer 50 is It is preferable that the ion conductivity is lower by two orders of magnitude or more.

FIG. 6 is a diagram illustrating the overall ionic conductivity of LAZP. FIG. 7 is a diagram illustrating the total ionic conductivity of LAGP. For example, at room temperature (25 ° C.), the overall ionic conductivity of LAZP is 3.5 × 10 ⁻⁹ S / cm, and the overall ionic conductivity of LAGP is 1.1 × 10 ⁻⁴ S / cm. Thus, at room temperature, the overall ionic conductivity of LAZP is about four digits lower than the overall ionic conductivity of LAGP. Similar results are obtained at other temperatures. Therefore, it is preferable to use LAZP for the first cover layer 10 and the second cover layer 50, and to use LAGP for the solid electrolyte layer 30.

  In the present embodiment, since the first cover layer 10 and the second cover layer 50 contain an oxide-based solid electrolyte as a main component, the first cover layer 10, the second cover layer 50, and the solid electrolyte layer 30 It will have a close composition. Thereby, it is possible to suppress interdiffusion at the time of firing between the first cover layer 10 and the second cover layer 50 and the solid electrolyte layer 30. Further, since the first cover layer 10 and the second cover layer 50 have lower ion conductivity than the solid electrolyte layer 30, it is possible to suppress an unexpected battery reaction via these.

  Preferably, the first margin layer 60 and the second margin layer 70 do not interdiffuse with the solid electrolyte layer 30 during firing. Therefore, in the present embodiment, it is preferable that the first blank layer 60 and the second blank layer 70 contain an oxide-based solid electrolyte as a main component. However, when the first margin layer 60 and the second margin layer 70 contain an oxide-based solid electrolyte as the main component, the ion conductivity of the first margin layer 60 and the second margin layer 70 may be increased. When the ion conductivity of the first margin layer 60 and the second margin layer 70 is high, the electrode layer at a certain position is not the adjacent counter electrode (electrode with different polarity) via the margin layer and the solid electrolyte layer 30, There is a possibility that a cell reaction may occur with the counter electrode located at one position. For example, as shown by the arrows in FIG. 3, in addition to the battery reaction with the negative electrode layer 41 in the nearest negative electrode 40 opposed via the solid electrolyte layer 30 in contact with the positive electrode layer 21 in the positive electrode 20, There is a possibility that a battery reaction may occur with the negative electrode layer 41 of the negative electrode 40 which is not the closest. Therefore, it is preferable that the first blank layer 60 and the second blank layer 70 have low ion conductivity as compared to the solid electrolyte layer 30. For example, it is preferable that the first blank layer 60 and the second blank layer 70 have substantially the same composition as the first cover layer 10 and the second cover layer 50.

  Subsequently, a method of manufacturing the all-solid battery 100 will be described. FIG. 8 is a diagram illustrating a flow of a method of manufacturing the all-solid battery 100.

(Green sheet production process)
The powder of the oxide-based solid electrolyte constituting the above-mentioned solid electrolyte layer 30 is prepared to have an appropriate particle size distribution, and is uniformly dispersed in water or an organic solvent together with a binder, a dispersing agent, a plasticizer, etc. Get At this time, a bead mill, a wet jet mill, various kneaders, a high pressure homogenizer, etc. can be used, and it is preferable to use a bead mill from the viewpoint of simultaneously performing adjustment and dispersion of particle size distribution. The obtained slurry can be coated to obtain a green sheet having a desired thickness. The coating method is not particularly limited, and a slot die method, a reverse coat method, a gravure coat method, a bar coat method, a doctor blade method or the like can be used.

(Cover sheet production process)
The powder of the oxide-based solid electrolyte constituting the first cover layer 10 described above is prepared to have an appropriate particle size distribution, and is uniformly dispersed in water or an organic solvent together with a binder, a binder, a plasticizer and the like. , Get a slurry. At this time, a bead mill, a wet jet mill, various kneaders, a high pressure homogenizer, etc. can be used, and it is preferable to use a bead mill from the viewpoint of simultaneously performing adjustment and dispersion of particle size distribution. The obtained slurry can be coated to obtain a green sheet having a desired thickness. The coating method is not particularly limited, and a slot die method, a reverse coat method, a gravure coat method, a bar coat method, a doctor blade method or the like can be used. A cover sheet for forming the second cover layer 50 can also be produced by the same method.

(Step of producing paste for electrode layer)
The electrode layer paste can be obtained by uniformly dispersing the conductive aid, the active material, the solid electrolyte material, the binder, the plasticizer and the like in water or an organic solvent. The electrode layer paste is used to form the positive electrode layer 21 and the negative electrode layer 41. Carbon, or Pd, Ni, Cu, Fe or an alloy containing these may be used as the conductive aid. A print layer of conductive metal paste for forming the current collector layers 22 and 42 is formed on one surface of the electrode layer paste, and a print layer of the electrode layer paste is further formed thereon.

(Lamination process)
A pattern of an electrode layer paste and a conductive metal paste for a current collector is disposed on a green sheet. Next, the powder of the oxide-based solid electrolyte constituting the first blank layer 60 and the second blank layer 70 is prepared to have an appropriate particle size distribution, and water or an organic solvent is used together with a binder, a dispersant, a plasticizer and the like. The paste for forming a blank layer is obtained by uniformly dispersing in the above. Next, the blank layer forming paste is printed on the blank portion on the green sheet. The printing method is not particularly limited, and a screen printing method, an intaglio printing method, a letterpress printing method, a calender roll method, or the like can be used. While screen printing is considered to be the most common for producing laminated devices with thin layers and high lamination, in some cases it may be preferable to apply ink jet printing when very fine electrode patterns or special shapes are required. A laminated body is obtained by laminating | stacking a required number of green sheets, arrange | positioning a cover sheet to outermost layer, and crimping | bonding it.

(Firing process)
Next, the obtained laminate is fired. The firing conditions include an oxidizing atmosphere or a non-oxidizing atmosphere, and the maximum temperature is preferably 400 ° C. to 1000 ° C., more preferably 500 ° C. to 900 ° C., without particular limitation. A step of holding at a temperature lower than the maximum temperature in the oxidizing atmosphere may be provided to sufficiently remove the binder until the maximum temperature is reached. In order to reduce the process cost, it is desirable to bake at a temperature as low as possible. After firing, re-oxidation may be performed. In this manner, all solid state battery 100 is manufactured.

  As mentioned above, although the embodiment of the present invention has been described in detail, the present invention is not limited to the specific embodiment, and various modifications may be made within the scope of the present invention described in the claims. Changes are possible.

10 first cover layer 20 positive electrode 21 positive electrode layer 22 current collector layer 25 first edge 30 solid electrolyte layer 40 negative electrode 41 negative electrode layer 42 current collector layer 45 second edge 50 second cover layer 60 first margin layer 70 Second margin layer 80 first external electrode 90 second external electrode 100 all solid state battery 200 battery module 300 outer can

Claims (4)

A solid electrolyte layer,
A positive electrode layer formed on one surface of the solid electrolyte layer;
A negative electrode layer formed on the other surface of the solid electrolyte layer;
A first cover layer laminated on a first outermost layer in a lamination direction in the laminated structure including the solid electrolyte layer, the positive electrode layer, and the negative electrode layer;
And a second cover layer laminated on a second outermost layer opposite to the first outermost layer in the laminated structure.
The all-solid-state battery, wherein the first cover layer and the second cover layer contain as a main component a solid electrolyte whose ion conductivity is lower than that of the solid electrolyte layer.   The all solid battery according to claim 1, wherein the solid electrolyte layer contains a solid electrolyte of a NASICON type crystal structure as a main component.   The all-solid body according to claim 1 or 2, characterized in that, at the same temperature, the total ion conductivity of the first cover layer and the second cover layer is two or more orders of magnitude lower than the total ion conductivity of the solid electrolyte layer. battery.   The first cover layer and the second cover layer are mainly composed of a solid electrolyte having a ratio of Zr larger than that of the main component solid electrolyte of the solid electrolyte layer. The all-solid-state battery as described in a term.

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