JP6217286B2 - All-solid battery and method for manufacturing the same - Google Patents

Description

  The present invention relates to an all-solid battery including a unit cell structure composed of a sintered body of a pair of a positive electrode layer and a negative electrode layer laminated with a solid electrolyte layer interposed therebetween, and a method for manufacturing the same.

  In recent years, in order to solve the safety problem due to leakage of organic electrolyte and the heat resistance problem due to volatilization of organic electrolyte exceeding its boiling point at high temperature, the conduction of lithium ions between the positive electrode layer and the negative electrode layer has been reduced. There has been proposed an all solid-state lithium ion battery (hereinafter referred to as “all solid battery”) that does not use an organic electrolyte solution as an intermediate electrolyte layer (see, for example, Patent Document 1). For example, as shown in a cross-sectional view as an example of the conventional all-solid battery in FIG. 13, the all-solid battery 500 is disposed between the positive electrode layer 501 and the negative electrode layer 502, and between the positive electrode layer 501 and the negative electrode layer 502. A unit cell structure having a solid electrolyte layer 503 is provided. Further, in the all solid state battery 500 shown in FIG. 13, a buffer layer 504 is disposed to buffer the bias of lithium ions at the interface between the positive electrode layer 501 and the solid electrolyte layer 503.

  Note that the positive electrode layer 501 is a layer including a positive electrode active material that occludes and releases lithium ions. The negative electrode layer 502 is a layer including a negative electrode active material that occludes and releases lithium ions. In all solid state battery 500, positive electrode current collector 505 is formed on the main surface of positive electrode layer 501 opposite to solid electrolyte layer 503, and negative electrode current collector is formed on the main surface of negative electrode layer 502 opposite to solid electrolyte layer 503. A body 506 is formed. The solid electrolyte layer 503 is an oxide or sulfide solid electrolyte having lithium ion conductivity.

JP 2010-80118 A (paragraphs 0026 to 0043, FIG. 1, etc.)

  In the all-solid battery 500 described above, as shown in FIG. 13, the distance between the end face of the positive electrode layer 501 and the negative electrode layer 502 that are not covered with the solid electrolyte layer 503 is short. Therefore, there is a possibility that the end face of the positive electrode layer 501 and the end face of the negative electrode layer 502 are short-circuited by contacting or discharging through the outside of the end face of the solid electrolyte layer 503.

  This invention is made | formed in view of an above-described subject, and it aims at providing the technique which can prevent that the end surface of the positive electrode layer of a single battery structure and the end surface of a negative electrode layer short-circuit.

In order to achieve the above-described object, an all solid state battery of the present invention comprises an all solid state battery comprising a single cell structure comprising a set of a positive electrode layer and a negative electrode layer sintered body with a solid electrolyte layer interposed therebetween. In the single cell structure, at least a part of one of the end face of the positive electrode layer and the end face of the negative electrode layer includes a step portion formed by being displaced with respect to the other end face , The size of the position shift of the step portion is 1 μm to 100 μm .

In the invention configured as described above, a unit cell structure is formed which includes a sintered body of a pair of a positive electrode layer and a negative electrode layer stacked with a solid electrolyte layer interposed therebetween. The unit cell structure also includes a step portion formed by shifting at least a part of one of the end face of the positive electrode layer and the end face of the negative electrode layer in the surface direction with respect to the other end face. Therefore, in the stepped portion, the distance between the end face of the positive electrode layer and the end face of the negative electrode layer increases by the amount of positional deviation. Therefore, it is possible to prevent the end face of the positive electrode layer not covered with the solid electrolyte layer and the end face of the negative electrode layer from coming into contact with each other via the outside of the end face of the solid electrolyte layer, or from being short-circuited. . Moreover, the above-mentioned short circuit can be effectively prevented as the magnitude | size of the position shift of the said level | step-difference part is 1 micrometer-100 micrometers.

  The solid electrolyte layer may cover the entire surface of the positive electrode layer and the negative electrode layer facing each other across the solid electrolyte layer, and end surfaces of the stepped portions may protrude outward.

  If comprised in this way, in the level | step-difference part, the part protruded outward of the end surface of a solid electrolyte layer will be arrange | positioned between the end surface of a positive electrode layer, and the end surface of a negative electrode layer. Therefore, the end surface of the positive electrode layer and the end surface of the negative electrode layer are disposed outside the end surface of the solid electrolyte layer by the protruding portion of the end surface of the solid electrolyte layer disposed between the end surface of the positive electrode layer and the end surface of the negative electrode layer. It is possible to more effectively prevent a short circuit due to contact or discharge.

The size of the displacement of the front Symbol step portion and is 4Myuemu～20myuemu, in the manufacturing process of the all-solid-state battery, it is easy to form the misalignment positive electrode layer and negative electrode layer, a unit cell structure The step portion can be easily formed.

  Also, a plurality of the unit cell structures may be provided, and the unit cell structures may be stacked and connected in series, or a plurality of the unit cell structures may be provided and the unit cell structures may be stacked and connected in parallel. Also good.

  If comprised in this way, a practical all-solid-state battery provided with a predetermined output voltage and a predetermined battery capacity can be provided.

In addition, the method for producing an all-solid battery according to the present invention is a method for producing an all-solid battery having a single cell structure comprising a sintered body of a pair of positive electrode layer and negative electrode layer laminated with a solid electrolyte layer interposed therebetween. The positive electrode layer having a step formed by shifting at least a part of one of the end face of the positive electrode layer and the end face of the negative electrode layer with respect to the other end face, the solid electrolyte layer, and A stacking step of forming a laminate of the negative electrode layer, and a firing step of firing the laminate, and the displacement of the stepped portion is caused by a difference in contraction rate between the positive electrode layer and the negative electrode layer during the firing step. It is controlled by using, and the size of the positional deviation of the stepped portion is 1 μm to 100 μm .

  In the invention thus configured, a positive electrode layer having a step portion formed by shifting at least part of one of the end face of the positive electrode layer and the end face of the negative electrode layer with respect to the other end face, a solid A laminate of the electrolyte layer and the negative electrode layer is formed. Therefore, an all solid state battery having a single cell structure made of a sintered body having a stepped portion can be easily manufactured by firing the thus formed laminated body.

  Further, the positive electrode layer and the negative electrode layer may be formed of materials having different thermal shrinkage rates. In this case, a unit cell made of a sintered body is produced by using the difference in shrinkage rate when the laminate is fired to cause a positional shift between the end face of the positive electrode layer and the end face of the negative electrode layer. A step portion can be easily formed in the structure.

  Further, in the firing step, the laminate may be sandwiched between two flat plates having thermal conductivity and fired while being pressed.

  In this way, the laminate is fired while being sandwiched and pressed between the two plates having thermal conductivity, so that the flat plate between the layer in contact with the flat plate and the layer not in contact with the flat plate of the laminate is obtained. A difference occurs in the shrinkage rate due to the frictional resistance at the contact portion. Therefore, displacement occurs between the end face of the positive electrode layer and the end face of the negative electrode layer, and a step portion can be formed in the unit cell structure made of a sintered body. Moreover, a sintered body having a smooth surface can be formed by sandwiching the laminated body between flat plates. Moreover, the magnitude | size of the position shift in a level | step-difference part is controllable by adjusting the applied pressure with respect to a laminated body.

According to the present invention, the end face of the positive electrode layer is formed in a step portion formed by shifting at least part of one of the end face of the positive electrode layer and the end face of the negative electrode layer in the plane direction with respect to the other end face. And the end face of the negative electrode layer increase by the amount of positional deviation. Therefore, it is possible to prevent the end face of the positive electrode layer not covered with the solid electrolyte layer and the end face of the negative electrode layer from coming into contact with each other via the outside of the end face of the solid electrolyte layer, or from being short-circuited. . Moreover, the above-mentioned short circuit can be effectively prevented as the magnitude | size of the position shift of the said level | step-difference part is 1 micrometer-100 micrometers.

It is a figure which shows the all-solid-state battery concerning 1st Embodiment of this invention, (a) is a perspective sectional view, (b) is a principal part enlarged view of (a). It is a principal part enlarged view which shows the modification of a level | step-difference part, Comprising: (a) and (b) show a different example, respectively. It is a perspective sectional view showing a modification of a step part. It is a perspective sectional view showing a modification of a step part. It is a figure which shows the all-solid-state battery concerning 2nd Embodiment of this invention, (a) is a perspective sectional view, (b) is an AA arrow directional cross-sectional view of (a). It is a perspective sectional view for explaining an example (1). It is a perspective sectional view for explaining an example (2). It is a perspective sectional view for explaining an example (3). It is a perspective sectional view for explaining Example (4) and (5). It is a figure for demonstrating Example (6), Comprising: (a) is an exploded view, (b) is a perspective sectional view. It is a perspective view for demonstrating an Example (6). It is a figure which shows the comparison result of each Example and a comparative example. It is sectional drawing which shows an example of the conventional all-solid-state battery.

<First Embodiment>
A first embodiment of the present invention will be described with reference to FIG. 1A and 1B are diagrams showing an all solid state battery according to a first embodiment of the present invention, where FIG. 1A is a perspective sectional view, and FIG. 1B is an enlarged view of a main part showing a region surrounded by a dotted line in FIG. is there.

(Constitution)
As shown in FIGS. 1A and 1B, the all-solid-state battery 1 includes two unit cell structures 10 stacked via an internal electrode layer 2, and the internal electrode layer 2 stacked in a rectangular parallelepiped shape. And the single cell structure 10 is comprised with the sintered compact by baking. The unit cell structure 10 includes a pair of a positive electrode layer 12 and a negative electrode layer 13 stacked with a solid electrolyte layer 11 therebetween, and the unit cell structure 10 is stacked through the internal electrode layer 2. They are connected in series.

  Further, as shown in FIGS. 1A and 1B, each single cell structure 10 is provided on one side of the end face 12 a of the positive electrode layer 12 and the end face 13 a of the negative electrode layer 13 on all side faces of the all solid state battery 1. However, it is provided with the step part 3 formed by being displaced with respect to the other end face. The size of the positional deviation of the stepped portion 3 may be about 1 μm to about 100 μm, but preferably the size of the positional deviation of the stepped portion 3 is about 4 μm to about 20 μm.

  Further, as shown in FIG. 1B, the opposing surfaces of the positive electrode layer 12 and the negative electrode layer 13 stacked with the solid electrolyte layer 11 interposed therebetween are covered with the solid electrolyte layer 11 over the entire surface. Yes. Further, as shown in the figure, the end surface of the solid electrolyte layer 11 in the stepped portion 3 so as to close the opening formed by the lower end edge of the end surface 12a of the positive electrode layer 12 and the upper end edge of the end surface 13a of the negative electrode layer 13. 11a is formed.

  In this embodiment, each step portion 3 is formed by forming a step in substantially the same direction on each side surface of the all-solid-state battery 1, but the step formation direction of each step portion 3 is as follows. The single cell structure 10 may not be in the same direction, and the single cell structure 10 may include a plurality of step portions 3 having different step formation directions. Further, as in this embodiment, the stepped portions 3 do not have to be formed on all side surfaces of the all solid state battery 1 (all end surfaces of the unit cell structure 10), and a set of side surfaces of the all solid state battery 1 facing each other is not required. The step part 3 may be formed only in each. Further, the stepped portion 3 may be formed only on one side surface of all the side surfaces of the all solid state battery 1, as long as the stepped portion 3 is formed on at least a part of the end surface of the unit cell structure 10. Good.

  Next, an example of the manufacturing method of the all-solid battery 1 and another example will be briefly described.

(Example of manufacturing method)
In an example of the manufacturing method, first, the end face 12a of the positive electrode layer 12 is formed with a unit cell structure 10 composed of a sintered body of a pair of the positive electrode layer 12 and the negative electrode layer 13 stacked with the solid electrode layer 11 interposed therebetween. And the laminated body of the unit cell structure 10 before baking which has the level | step-difference part 3 formed by arrange | positioning at least one part of one of the end surfaces 13a of the negative electrode layer 13 with respect to the other end surface. Is formed (stacking step). At this time, a number of laminates of unit cell structures 10 before firing corresponding to the required configuration of the all-solid-state battery 1 are stacked via the internal electrode layer 2 so as to be connected in series or in parallel. And the all-solid-state battery 1 is completed by baking the completed laminated body (baking process).

  In this way, at least a part of one of the end surface 12a of the positive electrode layer 12 and the end surface 13a of the negative electrode layer 13 has a step portion 3 formed by being displaced with respect to the other end surface. Then, a laminate of the solid electrolyte layer 11 and the negative electrode layer 13 is formed. Therefore, the all-solid-state battery 1 provided with the single battery structure 10 which consists of a sintered compact which has the level | step-difference part 3 can be easily manufactured by baking the laminated body formed in this way.

(Other examples of manufacturing methods)
In another example of the manufacturing method, first, the unit cell structure 10 made of a sintered body of a pair of the positive electrode layer 12 and the negative electrode layer 13 stacked with the solid electrode layer 11 interposed therebetween is used as a unit. A laminate of the unit cell structure 10 before firing, in which the negative electrode layer 13 is laminated with the solid electrolyte layer 11 in between, is formed (lamination step). At this time, a number of laminates of unit cell structures 10 before firing corresponding to the required configuration of the all-solid-state battery 1 are stacked via the internal electrode layer 2 so as to be connected in series or in parallel. Subsequently, the completed laminate is fired in a state where a flat plate having thermal conductivity is disposed on at least one of the positive electrode layer 12 and the negative electrode layer 13, whereby the all-solid battery 1 is completed (firing step).

  In this way, a laminate in which the positive electrode layer 12 and the negative electrode layer 13 are laminated with the solid electrolyte layer 11 interposed therebetween, and a flat plate having thermal conductivity is disposed on at least one of the positive electrode layer 12 and the negative electrode layer 13. Baked in the state. Therefore, the layer in contact with the thermally conductive flat plate is preferentially heated, so that there is a difference in shrinkage rate and shrinkage timing inside the laminate. Therefore, a positional shift occurs between the end face 12a of the positive electrode layer 12 and the end face 13a of the negative electrode layer 13, and thus the stepped portion 3 can be formed in the unit cell structure 10 made of a sintered body.

  Moreover, in both above-described manufacturing method examples, in the firing step, the laminate may be fired while being sandwiched and pressed between two sheets of thermal conductivity. In this way, the laminate is fired while being sandwiched and pressed between the two plates having thermal conductivity, so that the flat plate between the layer in contact with the flat plate and the layer not in contact with the flat plate of the laminate is obtained. A difference occurs in the shrinkage rate due to the frictional resistance at the contact portion. Therefore, a positional shift occurs between the end face 12a of the positive electrode layer 12 and the end face 13a of the negative electrode layer 13, and thus the stepped portion 3 can be formed in the unit cell structure 10 made of a sintered body. Moreover, the sintered compact which has a smooth surface can be formed by the laminated body before baking being pinched with a flat plate, being pressurized and heated. Moreover, the magnitude | size of the position shift in the level | step-difference part 3 is controllable by adjusting the applied pressure with respect to a laminated body in the case of baking.

  Moreover, in both above-described manufacturing method examples, the positive electrode layer 12 and the negative electrode layer 13 may be formed of materials having different thermal shrinkage rates. In this way, by utilizing the difference in shrinkage rate when the laminate is fired, a positional shift is caused between the end face 12a of the positive electrode layer 12 and the end face 13a of the negative electrode layer 13, whereby the sintered body. The step portion 3 can be easily formed in the unit cell structure 10 made of the above.

(Modification)
Next, a modification will be described with reference to FIGS. FIG. 2 is an enlarged view of a main part showing a modified example of the step part, (a) and (b) showing different examples, and FIGS. 3 and 4 are perspective sectional views showing modified examples of the step part. It is. 2 (a) and 2 (b) are diagrams each showing a region surrounded by a dotted line in FIG. 1 (a). Below, it demonstrates centering on a different point from the example shown to Fig.1 (a), (b), and description of the structure is abbreviate | omitted by attaching | subjecting the same code | symbol about the same structure.

  2 (a) and 2 (b), the end surface 11a of the step portion 3 of the solid electrolyte layer 11 includes a lower end edge of the end surface 12a of the positive electrode layer 12 and an upper end edge of the end surface 13a of the negative electrode layer 13. Projecting outward from the opening formed by

  In the modification shown in FIG. 3, four unit cell structures 10 are connected in series by being stacked via the internal electrode layer 2. Further, the step portion 3 is formed only on a pair of side surfaces facing the left and right sides of the all solid state battery 1 as viewed in the same figure.

  In the example shown in FIG. 4, the step portion 3 is formed only on the left side surface of the all solid state battery 1 including the two unit cell structures 10 connected in series as viewed in the same figure.

  As described above, in this embodiment, the unit cell structure 10 formed of a sintered body of a pair of the positive electrode layer 12 and the negative electrode layer 13 stacked with the solid electrolyte layer 11 interposed therebetween is formed. Further, the unit cell structure 10 has a step portion formed by shifting at least a part of one of the end face 12a of the positive electrode layer 12 and the end face 13a of the negative electrode layer 13 in the plane direction with respect to the other end face. 3 is provided. Therefore, in the step portion 3, the distance between the end surface 12 a of the positive electrode layer 12 and the end surface 13 a of the negative electrode layer 13 increases by the amount of positional deviation. Accordingly, the end surface 12a of the positive electrode layer 12 and the end surface 13a of the negative electrode layer 13 that are not covered with the solid electrolyte layer 11 are short-circuited by contact or discharge through the outside of the end surface 11a of the solid electrolyte layer 11. Can be prevented.

  In the step portion 3, when the end surface 11 a of the solid electrolyte layer 11 protrudes outward, the protruding portion is disposed between the end surface 12 a of the positive electrode layer 12 and the end surface 13 a of the negative electrode layer 13. The Accordingly, the protruding portion of the end surface 11a of the solid electrolyte layer 11 disposed between the end surface 12a of the positive electrode layer 12 and the end surface 13a of the negative electrode layer 13 functions as a shielding wall, so that the end surface 12a of the positive electrode layer 12 and the negative electrode layer It is possible to more effectively prevent the end face 13a of 13 from being short-circuited by contacting or discharging through the outside of the end face 11a of the solid electrolyte layer 11.

  In addition, the above-mentioned short circuit can be effectively prevented as the magnitude | size of the position shift of the level | step-difference part 3 is 1 micrometer-100 micrometers. Moreover, when the magnitude of the positional deviation of the stepped portion 3 is 4 μm to 20 μm, the positive electrode layer 12 and the negative electrode layer 13 can be easily misaligned in the manufacturing process of the all-solid battery 1, and the unit cell The step 3 can be easily formed in the structure 10.

  Moreover, the practical all-solid-state battery 1 provided with a predetermined | prescribed output voltage and a predetermined | prescribed battery capacity can be provided by the several unit cell structure 10 being laminated | stacked and connected in series.

Second Embodiment
A second embodiment of the present invention will be described with reference to FIG. 5A and 5B are diagrams showing an all solid state battery according to a second embodiment of the present invention, in which FIG. 5A is a perspective sectional view, and FIG. 5B is a sectional view taken along line AA in FIG.

  The all solid state battery 1a shown in FIG. 5 is different from the all solid state battery 1 of the above-described embodiment in that a plurality of unit cell structures 10 are connected in parallel. Below, it demonstrates centering on a different point from above-mentioned 1st Embodiment, and description of the structure is abbreviate | omitted by attaching | subjecting the same code | symbol about another structure.

  As shown in FIGS. 5A and 5B, the all-solid-state battery 1a includes four unit cell structures 10 stacked via the internal electrode layer 2, and the internal electrode layer 2 stacked in a rectangular parallelepiped shape. The insulating layer 4 and the unit cell structure 10 are made of a sintered body. Further, the end surface of the positive electrode layer 12 of each unit cell structure 10 is drawn out to the right side surface of the all-solid battery 1a, and the end surface of the negative electrode layer 13 of each unit cell structure 10 is drawn out to the left side surface of the all-solid battery 1a. It is.

  Also, the first and third unit cell structures 10 from the top are arranged so that the positive electrode layer 12 is on the upper side, and the second and fourth unit cell structures 10 from the top have the negative electrode layer 13 It is arranged to be on the upper side. The right side surface of the all-solid-state battery 1a in a state where the positive electrode layer 12 of the second unit cell structure 10 from the top and the positive electrode layer 12 of the third unit cell structure 10 are connected by the internal electrode layer 2. Has been drawn to. Also, the negative electrode layer 13 of the first unit cell structure 10 from the top and the negative electrode layer 13 of the second unit cell structure 10, and the negative electrode layer 13 and the fourth unit of the third unit cell structure 10 from the top The negative electrode layer 13 of the unit cell structure 10 is drawn out to the left side surface of the all-solid-state battery 1a in a state of being connected by the internal electrode layer 2 respectively.

  Insulating layers 4 are disposed on both the left and right sides of the all solid state battery 1a. The positive electrode layers 12 drawn to the right side surface of the all solid state battery 1a are connected by an electrode film (not shown), and the negative electrode layers 13 drawn to the left side surface of the all solid state battery 1a are not shown. As a result, the single cell structures 10 are connected in parallel.

  Moreover, as shown in FIG.5 (b), the level | step-difference part 3 is formed in each unit cell structure 10 in the side surface of a front side and a back side toward the all-solid-state battery 1a of Fig.5 (a).

  As described above, in this embodiment, the same effects as those of the first embodiment described above can be obtained, and a plurality of unit cell structures 10 are stacked and connected in parallel, so that a predetermined output voltage or a predetermined value can be obtained. It is possible to provide a practical all-solid-state battery 1a having the following battery capacity.

<Example>
Examples will be described with reference to FIGS. 6 to 9 are perspective cross-sectional views for explaining the embodiment (1) to the embodiment (9), respectively. FIG. 10 is a diagram for explaining the embodiment (6), (a) is an exploded view, (b) is a perspective sectional view, and FIG. 11 is a perspective view for explaining the embodiment (6). . FIG. 12 is a diagram showing a comparison result between each example and a comparative example.

(slurry)
Each slurry was produced as follows.

Solid electrolyte slurry:
As a solid electrolyte material made of a phosphoric acid material, a glass powder containing a crystal phase of a NASICON structure having a composition of Li _1.5 Al _0.5 Ge _1.5 (PO ₄ ) ₃ as a main component, the glass powder, The polyvinyl acetal resin and alcohol were weighed at a weight ratio of 100: 15: 140. A polyvinyl acetal resin was dissolved in alcohol to prepare an organic vehicle, which was enclosed in a pot together with glass powder and media. After rotating on the pot rack, the media was taken out to produce a solid electrolyte slurry.

Positive electrode slurry:
A powder having a crystal phase of NASICON structure having a composition of Li ₃ V ₂ (PO ₄ ) ₃ , a carbon powder serving as a conductive material, and a composition of Li _1.5 Al _0.5 Ge _1.5 (PO ₄ ) ₃ . A positive electrode slurry was produced in the same manner as the solid electrolyte slurry described above, using a powder obtained by mixing glass powder having a weight ratio of 40:10:50.

Negative electrode slurry:
A powder having a crystal phase of anatase-type titanium oxide TiO _2, a carbon powder serving as a conductive material, and a glass powder having a composition of Li _1.5 Al _0.5 Ge _1.5 (PO ₄ ) ₃ are used in a weight ratio of 40:10. A negative electrode slurry was prepared in the same manner as the solid electrolyte slurry described above using the powder mixed at 50.

Internal electrode slurry:
Using a powder obtained by mixing a carbon powder serving as a conductive material and a glass ceramic powder having a composition of Li _1.0 Ge _2.0 (PO ₄ ) ₃ at a weight ratio of 10:90, the same as the above solid electrolyte slurry. Thus, an internal electrode slurry was prepared.

Insulating slurry:
Using a glass ceramic powder having a composition of Li _1.0 Ge _2.0 (PO ₄ ) ₃ , an insulating slurry was produced in the same manner as the above-described solid electrolyte slurry.

(Green sheet)
Each green sheet was produced as follows.

Solid electrolyte sheet:
A solid electrolyte sheet having a thickness of 9 μm was prepared by applying a solid electrolyte slurry on a polyethylene terephthalate (PET) film using a doctor blade method and drying the slurry on a hot plate heated to a temperature of 40 ° C. .

Positive electrode sheet:
Using the positive electrode slurry, a positive electrode sheet having a thickness of 35 μm was prepared in the same manner as the solid electrolyte sheet described above.
Negative electrode sheet:
Using the negative electrode slurry, a negative electrode sheet having a thickness of 25 μm was prepared in the same manner as the above-described solid electrolyte sheet.

Internal electrode sheet:
Using the internal electrode slurry, an internal electrode sheet having a thickness of 25 μm was produced in the same manner as the above-described solid electrolyte sheet.
Insulating sheet:
Using the insulating slurry, three types of insulating sheets having thicknesses of 70 μm, 95 μm, and 115 μm were prepared in the same manner as the solid electrolyte sheet described above.

(Example (1))
As shown in FIG. 6, Example (1) includes a positive electrode layer 12 formed by one positive electrode sheet, a solid electrolyte layer 11 formed by two solid electrolyte sheets, and a negative electrode layer 13 formed by one negative electrode sheet. Two unit cell structures 10 are formed in series. In addition, Example (1) is formed by baking the laminated body in which the level | step-difference part 3 was formed previously.

  First, a solid electrolyte sheet, a positive electrode sheet, a negative electrode sheet, and an internal electrode sheet are cut into a predetermined number of 10 mm × 25 mm. Next, a laminate in which two unit cell structures 10 including one positive electrode sheet, two solid electrolyte sheets, and one negative electrode sheet are laminated via one internal electrode sheet (internal electrode layer 2) is produced. The In addition, as shown in FIG. 6, a positive electrode sheet is laminated | stacked by shifting 10 micrometers in a facing direction (left-right direction in the figure) with respect to a negative electrode sheet.

  Moreover, each above-mentioned sheet | seat is laminated | stacked by repeating the operation | work peeled from a PET film, after pressure-pressing at the temperature of 60 degreeC. Finally, the laminate is isotropically pressed using a water pressure of 180 MPa.

  Next, the laminated body having a rectangular plan view shape of 10 mm × 25 mm is cut at an interval of 10 mm along the cutting line CL of FIG. It is separated into a laminate having the step portions 3 only on the side surfaces.

Subsequently, the separated laminate is baked at 400 ° C. in a nitrogen atmosphere to decompose and remove the polyacetal resin, and then baked at 550 ° C. in an oxygen atmosphere to remove the carbide of the resin. And the all-solid-state battery 1 (Example (1)) was obtained by baking a laminated body at 700 degreeC in nitrogen atmosphere. The laminate is fired while being pressed at 0.5 kg / cm ² in a state of being sandwiched between two heat conductive SiC flat plates.

  When the end surface of the sintered body of Example (1) was observed with an optical microscope (magnification: 600 times), as shown in FIG. 12, a stepped portion 3 having a positional deviation of 20 μm was formed. In addition, a metal paste was applied to both main surfaces of the sintered body of Example (1) and dried in a state where metal leads were buried to form a positive electrode terminal and a negative electrode terminal. And it charged to 6.5V by 30 microamperes in Ar atmosphere, Then, it hold | maintained at 6.5V for 10 hours. Thereafter, when the discharge capacity was measured by discharging to 0 V at 30 μA, a discharge capacity of about 250 μAh was obtained.

(Example (2))
In Example (2), as shown in FIG. 7, a positive electrode layer 12 formed by one positive electrode sheet, a solid electrolyte layer 11 formed by two solid electrolyte sheets, and a negative electrode layer 13 formed by one negative electrode sheet. That is, three unit cell structures 10 are formed in series. In addition, Example (2) is formed by baking the laminated body in which the level | step-difference part 3 was formed previously. And the all-solid-state battery 1 (Example (2)) was obtained like the above-mentioned Example (1).

  When the end surface of the sintered body of Example (2) was observed with an optical microscope (magnification: 600 times), as shown in FIG. 12, a stepped portion 3 having a positional deviation of 17 μm was formed. In addition, a metal paste was applied to both main surfaces of the sintered body of Example (2) and dried in a state where metal leads were buried to form a positive electrode terminal and a negative electrode terminal. And it charged to 9.75V by 30 microamperes in Ar atmosphere, Then, it hold | maintained at 9.75V for 10 hours. Thereafter, when the discharge capacity was measured by discharging to 0 V at 30 μA, a discharge capacity of about 250 μAh was obtained.

(Example (3))
As shown in FIG. 8, Example (3) includes a positive electrode layer 12 formed by one positive electrode sheet, a solid electrolyte layer 11 formed by two solid electrolyte sheets, and a negative electrode layer 13 formed by one negative electrode sheet. That is, four unit cell structures 10 are formed and connected in series. In addition, Example (3) is formed by baking the laminated body in which the level | step-difference part 3 is not formed previously.

  In the same manner as in Example (1) described above, as shown in FIG. 8, a laminate having a rectangular plan view shape of 25 mm × 25 mm is formed. Next, this laminated body is cut into pieces by being cut at 10 mm intervals along the cutting line CL in FIG. And the laminated body separated into pieces was baked like Example (1), and the all-solid-state battery 1 (Example (3)) was obtained.

  When the end surface of the sintered body of Example (3) was observed with an optical microscope (magnification: 600 times), as shown in FIG. 12, a stepped portion 3 having a positional deviation of 11 μm was formed. Further, a metal paste was applied to both main surfaces of the sintered body of Example (3) and dried in a state where metal leads were buried to form a positive electrode terminal and a negative electrode terminal. And it charged to 6.5V by 30 microamperes in Ar atmosphere, Then, it hold | maintained at 6.5V for 10 hours. Thereafter, when the discharge capacity was measured by discharging to 0 V at 30 μA, a discharge capacity of about 250 μAh was obtained.

(Example (4))
In Example (4), as shown in FIG. 9, a positive electrode layer 12 formed by one positive electrode sheet, a solid electrolyte layer 11 formed by two solid electrolyte sheets, and a negative electrode layer 13 formed by one negative electrode sheet. That is, three unit cell structures 10 are formed in series. In addition, Example (4) is formed by baking the laminated body in which the level | step-difference part 3 is not formed previously.

  In the same manner as in Example (3) described above, as shown in FIG. 9, a laminated body having a rectangular plan view shape of 25 mm × 25 mm is formed. Next, this laminated body is cut into pieces by being cut at 10 mm intervals along the cutting line CL of FIG. And the laminated body separated into pieces was baked like Example (3), and the all-solid-state battery 1 (Example (4)) was obtained.

  When the end surface of the sintered body of Example (4) was observed with an optical microscope (magnification: 600 times), as shown in FIG. 12, a stepped portion 3 having a positional deviation of 13 μm was formed. In addition, a metal paste was applied to both main surfaces of the sintered body of Example (4), and dried in a state where metal leads were buried to form a positive electrode terminal and a negative electrode terminal. And it charged to 9.75V by 30 microamperes in Ar atmosphere, Then, it hold | maintained at 9.75V for 10 hours. Thereafter, when the discharge capacity was measured by discharging to 0 V at 30 μA, a discharge capacity of about 250 μAh was obtained.

(Example (5))
In Example (5), as shown in FIG. 9, a positive electrode layer 12 formed by one positive electrode sheet, a solid electrolyte layer 11 formed by two solid electrolyte sheets, and a negative electrode layer 13 formed by one negative electrode sheet. That is, three unit cell structures 10 are formed in series. In addition, Example (5) is formed by baking the laminated body in which the level | step-difference part 3 is not formed previously.

In the same manner as in Example (4) described above, as shown in FIG. 9, a laminate having a rectangular plan view shape of 25 mm × 25 mm is formed. Next, this laminated body is cut into pieces by being cut at 10 mm intervals along the cutting line CL of FIG. And the laminated body separated into pieces was baked like Example (4), and the all-solid-state battery 1 (Example (5)) was obtained. In Example (5), the pressing force during firing is set to 5 kg / cm ² .

  When the end surface of the sintered body of Example (5) was observed with an optical microscope (magnification: 600 times), as shown in FIG. 12, a stepped portion 3 having a positional deviation of 7 μm was formed. In addition, a metal paste was applied to both main surfaces of the sintered body of Example (4), and dried in a state where metal leads were buried to form a positive electrode terminal and a negative electrode terminal. And it charged to 9.75V by 30 microamperes in Ar atmosphere, Then, it hold | maintained at 9.75V for 10 hours. Thereafter, when the discharge capacity was measured by discharging to 0 V at 30 μA, a discharge capacity of about 250 μAh was obtained.

(Example (6))
In Example (6), as shown in FIGS. 10A and 10B, four unit cell structures 10 are connected in parallel. In addition, Example (6) is formed by baking the laminated body in which the level | step-difference part 3 is not formed previously.

  First, each laminated body block is produced as follows (refer Fig.10 (a)).

First positive electrode block 21:
The first positive electrode block 21 is formed by sequentially stacking one solid electrolyte sheet (solid electrolyte layer 11), one positive electrode sheet (positive electrode layer 12), and one internal electrode sheet (internal electrode layer 2). It was produced by processing into a rectangular shape of 10.5 mm × length 25 mm.
Second positive electrode block 22:
The second positive electrode block 22 includes one solid electrolyte sheet (solid electrolyte layer 11), one positive electrode sheet (positive electrode layer 12), one internal electrode sheet (internal electrode layer 2), and one positive electrode sheet (positive electrode layer 12). A solid electrolyte sheet (solid electrolyte layer 11), which was laminated in order, was produced by processing it into a rectangular shape having a width of 10.5 mm and a length of 25 mm.

Negative electrode block 31:
The negative electrode block 31 includes one solid electrolyte sheet (solid electrolyte layer 11), one negative electrode sheet (negative electrode layer 13), one internal electrode sheet (internal electrode layer 2), one negative electrode sheet (negative electrode layer 13), solid It was produced by processing one electrolyte sheet (solid electrode layer 11) laminated in order into a rectangular shape having a width of 17 mm and a length of 25 mm.

First insulating block 41:
The first insulating block 41 was produced by processing an insulating sheet having a thickness of 70 μm into a rectangular shape having a width of 4 mm × a length of 25 mm.
Second insulating block 42:
The second insulating block 42 was produced by processing a sheet having a thickness of 115 μm into a rectangular shape having a width of 4 mm and a length of 25 mm.
Third insulating block 43:
The third insulating block 43 was produced by processing a sheet having a thickness of 95 μm into a rectangular shape having a width of 4 mm and a length of 25 mm.

  Subsequently, the respective blocks described above are stacked in the following order (see FIGS. 10A and 10B).

  First, the first insulating block 41 is disposed between the two first positive electrode blocks 21. Next, the negative electrode block 31 is laminated, and the third insulating blocks 43 are laminated on both sides thereof. Subsequently, the second insulating block 42 and the second positive electrode block 22 arranged so as to sandwich the second insulating block 42 are laminated.

  Next, the negative electrode block 31 is laminated, and the third insulating blocks 43 are laminated on both sides thereof. Finally, the first insulating block 41 and the first positive electrode block 21 disposed so as to sandwich the first insulating block 41 are stacked.

  Each of the blocks described above is laminated by being repeatedly pressed and pressure-bonded at a temperature of 60 ° C. and then peeled off from the PET film. Finally, by performing isotropic pressure pressing using a water pressure of 180 MPa, a laminate having a rectangular plan view shape of 25 mm × 25 mm shown in FIG. 10B is formed.

  Note that the solid electrolyte sheet is laminated on each of the positive electrode blocks 21 and 22 and the negative electrode block 31 because the positive electrode layer 12 and the negative electrode layer 13 are in contact with each other due to misalignment at the time of lamination or bending of the sheet. This is to prevent this. Further, the size and configuration of each block described above are not limited to the above example.

  Next, the laminated body shown in FIG. 10B is cut along the cutting line CL to be separated into individual pieces, thereby forming a laminated body having a rectangular planar view shape of 10 mm × 10.5 mm. The And the laminated body separated into pieces was baked like Example (1), and the all-solid-state battery 1a (Example (6)) was obtained.

  When the end surface of the sintered body of Example (6) was observed with an optical microscope (magnification: 600 times), as shown in FIG. 12, a stepped portion 3 having a positional deviation of 4 μm was formed. Further, as shown in FIG. 11, a metal paste PA is applied to both sides of the sintered body (all-solid battery 1a) and dried with the metal leads buried therein, so that the positive terminal P and the negative terminal N are formed. Formed. And it charged to 3.25V by 120 microamperes in Ar atmosphere, Then, it hold | maintained at 3.25V for 10 hours. Then, it discharged to 0V at 120 microamperes and measured the discharge capacity.

(Comparative example)
The comparative example provided with one single cell structure formed by baking the laminated body in which the level | step-difference part 3 was not formed previously was produced.

  In the same manner as in Example (1) described above, one internal electrode sheet (internal electrode layer 2), one positive electrode sheet (positive electrode layer 12), four solid electrolyte sheets (solid electrolyte layer 11), negative electrode sheet (negative electrode) Two layers 13) and one internal electrode sheet (internal electrode layer 2) are laminated to form a laminate having a rectangular plan view shape of 25 mm × 25 mm. Next, this laminated body is cut into pieces by being cut at intervals of 10 mm. And the comparative example was obtained by baking the laminated body separated into pieces similarly to Example (1).

  When the end surface of the sintered body of the comparative example was observed with an optical microscope (magnification: 600 times), as shown in FIG. 12, there was no positional shift and the step 3 was not formed. Moreover, the metal paste was apply | coated to both the main surfaces of the sintered compact of a comparative example, and it dried in the state which made metal lead buried, and formed the positive electrode terminal and the negative electrode terminal. And it charged to 3.25V by 30 microamperes in Ar atmosphere, and hold | maintained at 3.25V for 10 hours. Thereafter, when the discharge capacity was measured by discharging to 0 V at 30 μA, a discharge capacity of about 250 μAh was obtained.

(Evaluation)
(1) As shown in FIG. 12, the stepped portion 3 having a larger positional deviation could be formed by forming the laminated body having the stepped portion 3 in advance. That is, in each of Examples (1) and (2), a displacement larger than the displacement (10 μm) of the stepped portion 3 before firing was confirmed after firing due to the difference in thermal shrinkage between the positive electrode layer 12 and the negative electrode layer 13. It was done.
(2) In Examples (3) to (5) in which the stepped portion 3 was formed in the laminate in which the stepped portion 3 was not formed due to the difference in thermal shrinkage between the positive electrode layer 12 and the negative electrode layer 13. A displacement of 7 μm to 13 μm was confirmed in the stepped portion 3. In the sintered body of Example (5) in which the pressing force during firing was increased, the size of the position difference of the stepped portion 3 was smaller than in Examples (3) and (4), and the applied pressure during firing was small. It was confirmed that the position shift size of the stepped portion 3 can be controlled by adjusting the pressure.
(3) In Example (6) in which the unit cell structure formed by forming a laminated body without the stepped portion 3 and firing it was connected in parallel, the heat between the positive electrode layer 12 and the negative electrode layer 13 Due to the difference in shrinkage rate, a position shift of 4 μm was confirmed in the stepped portion 3.
(4) In the comparative example using the positive electrode layer 12 and the negative electrode layer 13 having the same thermal shrinkage rate, in which a laminated body without the step portion 3 was formed, the step portion 3 was not confirmed.
(5) In each of Examples (1) to (5) and the comparative example, a discharge capacity of about 250 μAh was obtained, and it was confirmed that charging / discharging without problems occurred.

  The present invention is not limited to the above-described embodiments, and various modifications other than those described above can be made without departing from the spirit of the invention. The above numerical values are all examples, and the materials of the positive electrode layer and the negative electrode layer and the material of the solid electrolyte layer may be appropriately selected according to the configuration of the all solid state battery. In addition, the number of unit cell stacks may be changed as appropriate for the all solid state battery.

  Moreover, the lamination | stacking method of a positive electrode layer, a negative electrode layer, a solid electrolyte layer, an internal electrode layer, and an insulating layer is not limited to an above-described example, You may form a laminated body by the overcoating using screen printing. Further, a laminate may be formed by using green sheet production and screen printing in combination.

  The present invention can be widely applied to an all-solid battery including a unit cell structure made of a sintered body of a pair of positive electrode layer and negative electrode layer laminated with a solid electrolyte layer interposed therebetween, and a method for manufacturing the same.

DESCRIPTION OF SYMBOLS 1,1a All-solid-state battery 3 Step part 10 Single cell structure 11 Solid electrolyte layer 12 Positive electrode layer 12a End surface 13 Negative electrode layer 13a End surface

Claims (7)

In an all-solid-state battery comprising a single cell structure composed of a sintered body of a positive electrode layer and a negative electrode layer laminated with a solid electrolyte layer interposed therebetween,
The unit cell structure is
At least a part of one of the end face of the positive electrode layer and the end face of the negative electrode layer includes a step portion formed by being displaced with respect to the other end face ,
The all-solid-state battery, wherein the level difference of the stepped portion is 1 μm to 100 μm . The solid electrolyte layer covers the opposing surfaces of the positive electrode layer and the negative electrode layer sandwiching the solid electrolyte layer over the entire surface, and an end surface of the stepped portion protrudes outward. Item 2. The all solid state battery according to Item 1. All-solid-state cell according to claim 1 or 2 size of the displacement of the step portion, characterized in that it is a 4Myuemu～20myuemu. The all-solid-state battery according to any one of claims 1 to 3 , wherein a plurality of the single-cell structures are provided, and the single-cell structures are stacked and connected in series. The all-solid-state battery according to any one of claims 1 to 3 , wherein a plurality of the single-cell structures are provided, and the single-cell structures are stacked and connected in parallel. In a method for producing an all-solid battery comprising a unit cell structure comprising a sintered body of a pair of positive electrode layer and negative electrode layer laminated with a solid electrolyte layer interposed therebetween,
At least a part of one of the end face of the positive electrode layer and the end face of the negative electrode layer has a step portion formed by being displaced with respect to the other end face, the positive electrode layer, the solid electrolyte layer, and the A laminating step of forming a laminate of negative electrode layers;
A firing step of firing the laminate ,
The positional deviation of the stepped portion is controlled using the difference in shrinkage rate between the positive electrode layer and the negative electrode layer during the firing step,
The method of manufacturing an all-solid-state battery, wherein the stepped portion has a positional deviation of 1 μm to 100 μm . The method for producing an all solid state battery according to claim 6 , wherein in the firing step, the laminate is sandwiched between two flat plates having thermal conductivity and fired while being pressed.

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