WO2020175630A1

WO2020175630A1 - Solid-state secondary battery

Info

Publication number: WO2020175630A1
Application number: PCT/JP2020/008067
Authority: WO
Inventors: 泰輔益子; 田中　一正
Original assignee: Tdk株式会社
Priority date: 2019-02-27
Filing date: 2020-02-27
Publication date: 2020-09-03

Abstract

This solid-state secondary battery (100) has a positive electrode layer (1) including a positive electrode current collector (1A) and a positive electrode active material layer (1B), a negative electrode layer (2) including a negative electrode current collector (2A) and a negative electrode active material layer (2B), and a solid electrolyte layer (3) containing a solid electrolyte, wherein a laminate (20) is formed through alternate lamination of the positive electrode layer (1) and the negative electrode layer (2) with the solid electrolyte layer (3) therebetween, and the positive electrode current collector (1A) and the negative electrode current collector (2A) are each formed of a main portion (1Aa, 2Aa) including a first element as a main component, and a sub portion (1Ab, 2Ab) including a second element which is an element different from the first element.

Description

\¥0 2020/175 630 1 ((17 2020/008067 Clarification

Title of invention: All-solid-state secondary battery

Technical field

The present invention relates to an all solid state secondary battery.

The present application claims priority based on Japanese Patent Application No. 20 1 9-0 3 4 3 3 2 filed in Japan on February 27, 2010, the contents of which are incorporated herein by reference.

Background technology

[0002] In recent years, the development of electronic technology has been remarkable, and portable electronic devices have been made smaller, lighter, thinner, and have more functions. Along with this, there is a strong demand for smaller, lighter, thinner, and more reliable batteries for powering electronic devices. Lithium ion secondary batteries, which are currently used for general purposes, have conventionally used an electrolyte (electrolyte solution) such as an organic solvent as a medium for moving ions. However, in the battery with the above configuration, the electrolyte may leak out.

[0003]Since organic solvents and the like used in the electrolytic solution are flammable substances, it is required to further improve the safety of batteries. Therefore, as one measure to improve the safety of the battery, it has been proposed to use a solid electrolyte instead of the electrolytic solution as the electrolyte. Furthermore, the development of an all-solid-state secondary battery, in which a solid electrolyte is used as the electrolyte and other components are also solid, is underway.

[0004] Patent Document 1 discloses that a positive electrode current collector, a negative electrode current collector, a positive electrode active material, a negative electrode active material, a solid electrode which form an all-solid secondary battery by using an oxide-based solid electrolyte stable in air. It describes an all-solid-state secondary battery manufactured by a manufacturing method in which each of the densities is formed into a sheet, laminated to form a laminated body, and then fired simultaneously. At this time, 89, 01, 8, 8 and 1: are used as current collector elements.

[0005]Patent Document 2 describes an all-solid-state secondary battery in which, as a current collector element, O, R, or the like is used and fired in a low oxygen atmosphere. \¥02020/175630 2 (: 17 2020/008067 Prior art documents)

Patent literature

[0006] Patent Document 1: International Publication No. 2007/1 35790

Patent Document 2: JP 2007-227362 A

Summary of the invention

Problems to be Solved by the Invention

[0007] However, when a positive electrode current collector and a negative electrode current collector that are uniformly composed of a metal composed of one element or a metal alloy composed of two or more elements are used, the cycle characteristics are poor. There was a problem.

An object of the present invention is to provide an all solid state secondary battery having good cycle characteristics.

Means for solving the problem

[0009] The present invention provides the following means in order to solve the above problems.

(1) The all-solid secondary battery according to the first aspect of the present invention includes a positive electrode layer including a positive electrode current collector and a positive electrode active material layer, a negative electrode current collector and a negative electrode active material layer. A negative electrode layer including a solid electrolyte layer, and a solid electrolyte layer including a solid electrolyte, and the positive electrode layer and the negative electrode layer are alternately laminated with the solid electrolyte layer interposed therebetween to form a positive electrode current collector and the negative electrode. The current collector includes a main part containing a first element as a main component and a sub-part containing a second element which is an element different from the first element.

[0011] (2) In the all-solid-state secondary battery according to (1), the first element is

6, 8 9, 8 li, and I are elements selected from the group consisting of I, wherein the second element is 0, 1 \ 1 and 8 ₉ , 8 li,

It may be one or more elements selected from the group consisting of V, only IV!, 〇〇, “, 3 I, 06, 1_丨, and 8 丨.

[0012] (3) In the all-solid-state secondary battery according to (1) or (2), the weight ratio of the second element to the first element is in the range of 0.0002% or more and 20% or less. It may be inside. 〇 2020/175 630 3 (:171? 2020/008067

[0013] (4) In the all-solid-state secondary battery described in (1) to (3), the sub-area may have a circle area conversion diameter of 0.5 or less. Here, the circle area conversion diameter is calculated as = (3/71) ⁽¹ , ² , ²⁾ 2 when the area of the sub-portion in the 3rd 1\/1 image is 3.

(5) In the all-solid-state secondary battery described in (1) to (4), the sub-portion may be obtained by segregating an element containing the second element in the main portion.

Effect of the invention

[0015] According to the present invention, it is possible to provide an all-solid secondary battery having good cycle characteristics.

Brief description of the drawings

FIG. 1 is a schematic sectional view of an all solid state secondary battery according to the present embodiment.

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present embodiment will be described in detail with reference to the drawings as appropriate. In the drawings used in the following description, in order to make the features of this embodiment easier to understand, the features may be enlarged for convenience, and the dimensional proportions of each component may differ from the actual ones. Sometimes.

The substances, dimensions, and the like exemplified in the following description are examples, and the present embodiment is not limited to them, and may be appropriately modified and implemented within the range in which the effects of the present invention are exhibited.

[0018] Examples of the all-solid-state secondary battery include an all-solid-state lithium-ion secondary battery, an all-solid-state sodium ion secondary battery, and an all-solid magnesium-ion secondary battery. Hereinafter, an all-solid-state lithium ion secondary battery will be described as an example, but the present invention is applicable to all-solid-state secondary batteries in general.

[0019] Fig. 1 is an enlarged schematic cross-sectional view of a main part of the all-solid-state lithium-ion secondary battery according to the present embodiment.

The all-solid-state lithium-ion secondary battery shown in FIG. 1 includes a laminate having a first electrode layer, a second electrode layer, and a solid electrolyte layer. Hereinafter, one of the first electrode layer and the second electrode layer functions as a positive electrode and the other functions as a negative electrode. The polarity of the electrode layer changes depending on which polarity is applied to the external terminal. Below, understanding 〇 2020/175630 4 卩 (：171? 2020 /008067

In order to facilitate the above, the first electrode layer will be described as a positive electrode layer and the second electrode layer will be described as a negative electrode layer.

[0020] The all-solid-state lithium-ion secondary battery 100 includes a positive electrode current collector 18 and a positive electrode active material layer.

1) a positive electrode layer 1 including a positive electrode layer 1, a negative electrode current collector 28 and a negative electrode active material layer 2 including a negative electrode layer 2, and a solid electrolyte layer 3 including a solid electrolyte. Negative electrode layers 2 are provided with laminated bodies 20 that are alternately laminated with solid electrolyte layers 3 containing a solid electrolyte interposed therebetween.

[0021] The positive electrode layer 1 is connected to the first external terminal 6, and the negative electrode layer 2 is connected to the second external terminal 7, respectively. The first external terminal 6 and the second external terminal 7 are electrical contacts with the outside.

[0022] (Laminate)

The laminate 20 has a positive electrode layer 1, a negative electrode layer 2, and a solid electrolyte layer 3.

In the laminated body 20, the positive electrode layer 1 and the negative electrode layer 2 are alternately laminated with the solid electrolyte layer 3 (more specifically, the interlayer solid electrolyte layer 38) interposed therebetween. By exchanging lithium ions between the positive electrode layer 1 and the negative electrode layer 2 through the solid electrolyte layer 3, the all-solid-state lithium-ion secondary battery 100 is charged and discharged.

The number of layers of the positive electrode layer 1 and the negative electrode layer 2 is not particularly limited, but the total number of the positive electrode layer 1 and the negative electrode layer 2 is generally in the range of 10 to 200 layers, and preferably 20 layers. The above is within the range of 100 layers or less.

(Positive Electrode Layer and Negative Electrode Layer)

The positive electrode layer 1 has a positive electrode current collector 1 and a positive electrode active material layer 1 containing a positive electrode active material. The positive electrode current collector 18 includes, as main components, a main part 18 3 containing the first element and a sub part 18 s containing the second element which is an element different from the first element.

The negative electrode layer 2 has a negative electrode current collector 2 and a negative electrode active material layer 2 containing a negative electrode active material. Similarly to the positive electrode current collector 18, the negative electrode current collector 28 also has a main part that contains the first element as the main component, and a second part that contains the second element that is an element different from the first element. It consists of 2 heads. The positive electrode current collector 18 and the negative electrode current collector 28 may be formed in layers. 〇 2020/175630 5 卩(: 171-1?2020/008067

[0025] main portion 1 eight ₃ and main portion 2 eight ₃ of the negative electrode current collector 2 eight of the positive electrode current collector 1 eight includes high conductivity at least one element (first element). As the first element with high conductivity, for example, copper

Examples include elements selected from the group consisting of nickel (1\11), iron (4, silver (89), gold (8), palladium (0000), and platinum (). Among these metal elements, copper and nickel are preferable in consideration of the manufacturing cost in addition to the high conductivity Further, copper is difficult to react with the positive electrode active material, the negative electrode active material and the solid electrolyte. substance may be the same or different have good. main portion of the cathode current collector 1 eighth main portion 1 eight ₃ and the negative electrode current collector 2 eight constituting the collector 1 eight and the anode current collector 2 eight 2 8 ₃ may further include metal oxides.The metal oxides include: 〇ri 〇, 〇ri ₂ 〇, 1\1 I 〇, 6 ₂ 〇 ₃ , 6 ₃ 〇 ₄ , ₄ , etc. Is mentioned.

[0026] The sub-part 1 8 swatches of the positive electrode current collector 18 and the sub-part 2 8 swatches of the negative electrode current collector 2 8 are the second element which is an element different from the first element constituting the main part 18 3. including.

The second element is copper

Nickel (1\1丨), Iron (4, Silver (89), Gold (8), Palladium (○○, Platinum (), Vanadium (V), Titanium (Cho), Manganese (IV!n)) , Cobalt (○○), zirconium (○, silicon (3 丨), germanium (◦ 6), lithium (1_ 丨), and aluminum (8 丨), at least one element selected from the group consisting of Here, in the present specification, the “subpart” means that the concentration distribution of an element different from the first element contained as the main component of the current collector in the positive electrode current collector or the negative electrode current collector is high. Therefore, the positive electrode current collector 18 has a structure in which the sub-parts 18 13 are scattered, dispersed or mixed in the current collector composed of the main part 18 3 which is the main component. The sub-portion 18 is generated by segregation of an element containing the second element in the current collector consisting of the main portion 18 _3. Similarly, the negative electrode current collector 28 is the main component. Sub-parts 2 8 13 are scattered, scattered, or mixed in the current collector consisting of parts 2 8 3. The sub-part 2 8 s is the second part of the current collector consisting of the main part 2 8 ₃ . It is generated by the segregation of elements including elements In Figure 1, a part of the positive electrode current collector 18 and the negative electrode current collector 28 (the area indicated by the dotted circle) is expanded. In general, a configuration in which sub-parts are scattered, dispersed, or mixed in the current collector composed of the main part is shown.

There is an element common to the element used as the first element and the element used as the second element, but the main part and the sub-part are made of different elements, and are not the same element.

[0027] When the positive electrode current collector and the negative electrode current collector have such a configuration, the cycle characteristics of the all-solid secondary battery are improved. The reason for this is not clear at this point, but the following assumptions are made. Since the current collector has a sub-portion containing a second element different from the first element contained as the main component, a part having a different electron conductivity can be formed in the current collector. The presence of a part with different electron conductivity in the current collector causes a difference in how the electrons are taken out, which improves the cycle characteristics of the all-solid-state secondary battery.

[0028] In each of the positive electrode current collector 1A and the negative electrode current collector 2A, the weight ratio of the second element to the first element is preferably in the range of 0.0002 or more and 20% or less.

With this configuration, the cycle characteristics of the all-solid-state secondary battery become better. If the weight ratio of the second element to the first element is less than 0.0002%, the cycle characteristics are hardly affected. Also, if it exceeds 20%, there are too many prayers in the current collector, which may rather deteriorate the cycle characteristics. The weight ratio of the second element to the first element is more preferably 15% or less, still more preferably 10% or less, and even more preferably 1% or less.

[0029] The weight ratio of the second element to the first element can be obtained by a known method.

For example, laser irradiation induced plasma mass spectrometry (L a s e r A b l a t i o n I n d u c t i v e l y Co u p l e d P l a s m a Ma s s

Spectrome try :LA- ICP-MS). By using LA-CP-MS, a single laser beam is focused and irradiated on the cross-section or surface of the current collector to evaporate/particulate, decompose and ionize in plasma, and generate ions in a mass spectrometer. The first element and the second element 〇 2020/175 630 7 卩(: 171-1? 2020/008067

The weight of the element can be obtained. Since the region irradiated with laser light is the target of analysis, it is possible to obtain local information from the current collector by narrowing down the spot diameter of laser light. Even when the spot diameter of the laser beam is larger than the thickness of the metal current collector, an accurate weight ratio can be obtained by comparing the weight ratios of the first metal element and the second metal element. it can.

[0030] The circle area calculated diameter ¢1 of the sub-part 18 sq. of the positive electrode current collector 18 and the sub-part 28 sq. of the negative electrode current collector 28 is preferably 0.5 or less.

With this configuration, the cycle characteristics of the all-solid-state secondary battery become better. If the circle area conversion diameter is larger than 0.5, the bias in the current collector is too large, which may rather deteriorate the cycle characteristics.

[0031] In the present specification, the "circular area conversion diameter" means to obtain an electron microscope (3M IV!) image of a cross section of an arbitrary predetermined number n of current collectors (for example, n = 2), It is obtained with ¢1 = {^ / %) ² 2 where the area of 3 images of each subpart is arbitrarily set (eg, ^ = 20) in the 3M IV! image of each cross section. .. As described above, it is preferable that the maximum diameter is 0.5 or less among the “circular area conversion diameters” of the _n cm sub parts thus obtained.

[0032] The thickness of the positive electrode current collector 18 and the negative electrode current collector 28 is not limited, but in the case of safety, it is in the range of 0.5 or more and 30 or less.

The positive electrode active material layer 1 is formed on one side or both sides of the positive electrode current collector 18. For example, the positive electrode layer 1, which is the uppermost layer in the stacking direction of the all-solid-state lithium-ion secondary battery 100, does not have the negative electrode layer 2 facing the stacking direction upper side. Therefore, the positive electrode active material layer 1 in the positive electrode layer 1, which is the uppermost layer of the all-solid-state lithium-ion secondary battery 100, need only be on one side on the lower side in the stacking direction. There is no. The negative electrode active material layer 2 is also formed on one side or both sides of the negative electrode current collector 2, similarly to the positive electrode active material layer 1. The thickness of the positive electrode active material layer 1 and the negative electrode active material layer 2 is preferably in the range of 0.5 or more and 5.0 or less. By increasing the thickness of the positive electrode active material layer 1 and the negative electrode active material layer 2 to 0.5 or more, the electric capacity of the all-solid-state lithium-ion secondary battery can be increased. 〇 2020/175630 8 卩(: 171-1?2020/008067

On the other hand, by setting the thickness to be 5.0 or less, the diffusion distance of lithium ions is shortened, so that the internal resistance of the all-solid-state lithium-ion secondary battery can be further reduced.

[0034] The positive electrode active material layer 1 and the negative electrode active material layer 2 each include a positive electrode active material or a negative electrode active material that exchanges lithium ions and electrons. In addition to this, a conductive auxiliary agent or the like may be included. It is preferable that the positive electrode active material and the negative electrode active material can efficiently insert and desorb lithium ions.

[0035] There is no clear distinction between the active materials constituting the positive electrode active material layer 1 or the negative electrode active material layer 2 and the potentials of the two compounds are compared, and the compound showing a more noble potential is determined as the positive electrode. A compound showing a more base potential can be used as the negative electrode active material. Therefore, the active materials will be collectively described below.

[0036] As the active material, a transition metal oxide, a transition metal composite oxide, or the like can be used. For example, as transition metal oxides and transition metal composite oxides, lithium manganese composite oxide 1_ 丨₂ 1\/^ ₃ 1\/13 _{1 -3} 〇 ₃ (0.8 £a £ ^ .1\/ 1 ₃ = 〇〇,

), Lithium cobaltate (1_丨thousand _2), lithium nickelate (1 -丨1 \ 1 1 〇 2), lithium manganese spinel (1 -丨IV n ₂ 〇 _4), the general formula:! 1_丨1 \1 丨〇〇 1 \/1 门₂ 〇 ₂ (X + V + 2 = 1 _% 0 £ X £ 1 _% 0 £ V £ 1 _X 0 £ å £ 1) Lithium, a mixed metal oxide Vanadium compound (!_ 丨₂ 0 ₅ ), olivine

Tada Hachijo, “One or more elements selected from”, Lithium vanadium phosphate

〇〇, 1\1丨) is represented! -丨 Excess solid solution positive electrode, lithium titanate (1 _ 1 _{4 4} 1 ₅ 0 ₁₂ ), pyrophosphate compound!- 1 _{1 +>} ( ₆ ~ ₂ 0 ₇ (○ £ father £

I + Li + ▽ <1.1) and other complex metal oxides.

The positive electrode current collector 1 and the negative electrode current collector 2 may include a positive electrode active material and a negative electrode active material, respectively. The content ratio of the active material contained in each current collector is 〇 2020/175 639 9 (: 171-1? 2020 /008067

There is no particular limitation as long as it functions as. For example, the volume ratio of the positive electrode current collector/positive electrode active material or the negative electrode current collector/negative electrode active material is preferably in the range of 90/10 to 60/40.

[0038] Since the positive electrode current collector 1 and the negative electrode current collector 2 include the positive electrode active material and the negative electrode active material, respectively, the positive electrode current collector 18 and the positive electrode active material layer 1 and the negative electrode current collector 28 and the negative electrode are formed. Adhesion with the active material layer 2 is improved.

(0039) (Solid electrolyte layer)

As shown in FIG. 1, solid electrolyte layer 3 has interlayer solid electrolyte layer 38 located between positive electrode active material layer 1 and negative electrode active material layer 2.

The solid electrolyte layer 3 is the outermost solid located outside either or both of the positive electrode layer 1 (positive electrode current collector 18) and the negative electrode layer 2 (negative electrode current collector 28) (both in FIG. 1). The electrolyte layer 3 may be further provided. Here, the “outside” means a laminated body.

It means the outer side of the positive electrode layer 1 or the negative electrode layer 2 that is closest to the surface 58 of the 20 and the 5th surface.

The solid electrolyte layer 3 may not have the outermost solid electrolyte layer 3, and in this case, the surfaces 58 and 5 of the laminate 20 are the positive electrode layer 1 or the negative electrode layer 2.

[0040] For the solid electrolyte layer 3, it is preferable to use a substance having low electron conductivity and high lithium ion conductivity. The solid electrolyte is, for example,

〇. ₅ 1_丨〇. Berobusukai preparative compounds such as ₅ chome I 〇 ₃ and, 1_丨_l4 Z n (060 _{₄₎ 4} Rishi Con type compounds such as,

G-type compound, 1_丨“ ₂

(1^ 〇 4) 3, then I 1.3 8 I 0 3 chome 1 I 7 (〇 4) 3 palm; 1.5 8 I 0 5 ^ ⁶ 1. 5

(〇 ₄ ) _3, such as Nasicon-type compounds,! -...丨₃ ₂₅ Rei_6_rei ₂₅ 〇 ₇₅ 3 ₄ or 1 _ 1 ₃ 3 ₄ Chiorishikon type compounds such as, 1_ 1 ₂ 3 ₂ 3 ₅ and 1_ 1 ₂ 〇 - ₂ 〇 ₅ -

3 I 〇 ₂ glass compounds such as 1-1 ₃ 〇 ₄ and 1_ I _3. ₅ 3 I_〇. ₅ 〇. ₅ 〇 ₄ and 1_ 1 _2.9 〇 _3. ₃ 1 \ 1 〇. Phosphorus, such as ₄₆ Desirably it is at least a species selected from the group consisting of acid compounds.

[0041] The solid electrolyte layer 3 is preferably selected according to the active materials used for the positive electrode layer 1 and the negative electrode layer 2. For example, the solid electrolyte layer 3 is a component of the active material. 〇 2020/175 630 10 卩 (：171? 2020 /008067

It is more preferable to contain the same element as the element. Since the solid electrolyte layer 3 contains the same elements as the constituent elements of the active material, the bonding at the interface between the positive electrode active material layer 1 and the negative electrode active material layer 2 and the solid electrolyte layer 3 is strong. become. Further, the contact area at the interface between the positive electrode active material layer 1 and the negative electrode active material layer 2 and the solid electrolyte layer 3 can be widened.

[0042] The thickness of the inter-layer solid electrolyte layer 38 is preferably in the range of not less than 0.5 and not more than 20. By setting the thickness of the inter-layer solid electrolyte layer 38 to be 0.5 or more, it is possible to reliably prevent a short circuit between the positive electrode layer 1 and the negative electrode layer 2, and to set the thickness to 20.0 or less. As a result, the migration distance of lithium ions is shortened, and the internal resistance of the all-solid-state lithium-ion secondary battery can be further reduced.

[0043] The thickness of the outermost solid electrolyte layer 3 is not particularly limited, but, for example, as a guide, it is preferably 20 or more and 100 or less. When the thickness is 20 111 or more, the positive electrode layer 1 or the negative electrode layer 2 which is closest to the surfaces 58 and 5 of the laminate 20 is less likely to be oxidized due to the influence of the atmosphere in the firing process and has a high capacity. It becomes an all-solid-state lithium-ion secondary battery. Further, if the thickness is 100 or less, the all-solid-state lithium-ion secondary battery will have sufficient moisture resistance even under the environment of high temperature and high humidity, high reliability, and high volume energy density.

[0044] (Margin layer)

As shown in FIG. 1, the laminate 20 may include a solid electrolyte and may include a margin layer 4 arranged side by side with each of the positive electrode layer 1 and the negative electrode layer 2. The margin layer 4 is preferably provided to eliminate the step between the inter-layer solid electrolyte layer 38 and the positive electrode layer 1, and the step between the inter-layer solid electrolyte layer 38 and the negative electrode layer 2. Therefore, the margin layer 4 has substantially the same height as the positive electrode layer 1 or the negative electrode layer 2 in the area other than the positive electrode layer 1 and the negative electrode layer 2 on the main surface of the solid electrolyte layer 3 (that is, the positive electrode layer 1 and the negative electrode layer 2). 2) to be placed side by side on each. Due to the presence of margin layer 4, solid electrolyte layer 3 and positive electrode layer 1 〇 2020/175 630 1 1 卩 (：171? 2020 /008067

In addition, since the steps between the solid electrolyte layer 3 and the negative electrode layer 2 are eliminated, the solid electrolyte layer 3 and each electrode layer are highly dense, and delamination or warpage occurs due to firing of the all-solid-state battery. It gets harder.

The material forming the margin layer 4 is not particularly limited, but it is preferable to include a material having a heat shrinkage behavior similar to that of the solid electrolyte 3 in the firing step described later. For example, if the solid electrolyte 3 is lithium aluminum aluminum phosphate 1_丨_{1 +} ^ I D (0 ₄ ) ₃ (0 £ father £ 0 .6), the margin layer 4 is also lithium aluminum lithium phosphate 1_ 1 _{1 +.} ^ I ,7 I ₂ _ ,( 〇 ₄ ) ₃ (0 £ father £ 0 ·

6) is preferably included. Since the solid electrolyte 3 and the margin layer 4 are made of the same material, cracks due to the difference in heat shrinkage are unlikely to occur, and the solid electrolyte 3 and the margin layer 4 have good interfacial bonding. Further, the margin layer 4 may include a material other than the solid electrolyte, and as the material forming the margin layer 4, for example, the active material material forming the positive electrode active material 1 or the negative electrode active material layer 2 can be used. glass material is effective in binding improvement (Snake丨₂ 0 _3. 3 I 〇 _2, including etc. Snake ₂ 〇 _3, Z N_〇) and the like, such as.

[0046] (terminal)

For the first external terminal 6 and the second external terminal 7 of the all-solid-state lithium ion secondary battery 100, it is preferable to use a material having high conductivity. For example, silver (eight _9), gold (Hachiri), platinum (1 :), aluminum (eight丨), copper (〇 Li), tin (3 n), nickel (1 \ 1丨), chromium (O O The terminal may be a single layer or multiple layers.

[0047] (Protective layer)

The all-solid-state lithium-ion secondary battery 100 may have a protective layer (not shown) for electrically, physically and chemically protecting the laminated body 20 and terminals on the outer periphery of the laminated body 20. .. The material forming the protective layer is preferably excellent in insulating property, durability, moisture resistance and environmentally safe. For example, it is preferable to use glass, ceramics, thermosetting resin, or photocurable resin. The material of the protective layer may be only one kind or a combination of plural kinds. In addition, the protective layer may be a single layer 〇 2020/175 630 12 boxes (：171? 2020 /008067

It is preferable to have it. Among them, an organic-inorganic hybrid obtained by mixing a thermosetting resin and a ceramic powder is particularly preferable.

(Method for manufacturing all-solid-state lithium-ion secondary battery)

The all-solid-state lithium-ion secondary battery 100 may be manufactured by the simultaneous firing method or the sequential firing method. The co-firing method is a method in which the materials forming the respective layers are laminated, and a laminated body is produced by simultaneous firing. The sequential firing method is a method of sequentially producing each layer, and a firing step is performed each time each layer is produced. The simultaneous baking method can reduce the work steps of the all-solid-state lithium-ion secondary battery 100. Further, when the co-firing method is used, the obtained laminated body 20 becomes denser. Hereinafter, the case of using the simultaneous firing method will be described as an example.

[0049] The co-firing method includes a step of forming a paste of each material constituting the laminated body 20, a step of applying a paste and drying the paste to produce a green sheet, and a step of laminating a green sheet And simultaneously firing the body.

[0050] First, the positive electrode current collector 18 constituting the laminate 20, the positive electrode active material layer 1 m, the solid electrolyte layer 3, the negative electrode active material layer 2 m, the negative electrode current collector 28, and the margin layer 4 Paste each material of.

[0051] When the positive electrode current collector 18 and the negative electrode current collector 28 are used to prepare a current collector base material by the usual method, the second element constituting the sub-parts 1 and 2 is the active material after firing. The layer diffuses into the solid electrolyte layer and remains on the current collector, so that it cannot form a bias.

Therefore, by coating the powder containing the first element forming the main parts 18 3 and 2 8 3 of the current collector with the powder containing the second element forming the sub parts 1 8 and 2 8 Even after firing, it remains on the current collector and forms sub-parts 1 and 2. As a coating method, not only the resinate (organic metal solution) method used in the examples described below, but also other known coating methods may be used.

As a method of changing the size and amount of the sub-portion, for example, first, prepare a current collector element powder with a large amount of segregating element (thick coating), 〇 2020/175 630 13 卩(：171? 2020/008067

The coated current collector element powder and the uncoated current collector element powder are mixed, and the coated current collector element powder and the uncoated current collector element powder are mixed depending on the size and amount of the sub-part. A method of changing the ratio of the body element powder can be used.

[0052] The pasting method is not particularly limited. For example, a paste is obtained by mixing powder of each material with a vehicle. Here, the vehicle is a generic term for media in the liquid phase. The vehicle includes a solvent and a binder. By such a method, the paste for the positive electrode current collector 18; the paste for the positive electrode active material layer 1; the paste for the solid electrolyte layer 3; the paste for the negative electrode active material layer 2; and the negative electrode current collector 2 Make a paste for eight and a paste for margin layer 4.

Next, a green sheet is produced. The green sheet is obtained by applying the prepared paste onto a base material such as a knife (polyethylene terephthalate) in a desired order, drying it if necessary, and then peeling the base material. The method of applying the paste is not particularly limited. For example, known methods such as screen printing, coating, transfer, doctor blade, etc. can be used.

When producing the laminate 20, the positive electrode unit and the negative electrode unit described below can be prepared to produce the laminate.

[0055] First, a paste for solid electrolyte layer 3 is formed into a sheet shape on a knife film by a doctor blade method, and dried to form a solid electrolyte layer sheet. On the obtained solid electrolyte layer sheet, a paste for a positive electrode active material layer 1 is printed by screen printing and dried to form a positive electrode active material layer 1.

[0056] Next, the produced positive electrode active material layer 1 bottom is printed with a screen for a positive electrode current collector 18 by screen printing and dried to form a positive electrode current collector 18. Furthermore, a paste for the positive electrode active material layer 1 is printed again on the screen by screen printing and dried. Then, in the region of the solid electrolyte layer sheet other than the positive electrode layer 1, the margin layer 4 is screen-printed and dried to form the margin layer 4 having a height substantially equal to that of the positive electrode layer 1. Then, by peeling off the knife film, the positive electrode active material layer 1/positive electrode current collector 18/positive electrode active material layer is formed on the main surface of the solid electrolyte layer 3. 〇 2020/175 630 14 卩 (：171? 2020 /008067

A positive electrode unit is obtained in which the positive electrode layer 1 and the margin layer 4 in which the first layer is laminated in this order are formed.

[0057] By the same procedure, the negative electrode layer 2 and the margin layer in which the negative electrode active material layer 2 /negative electrode current collector 28 /negative electrode active material layer 2 were laminated in this order on the main surface of the solid electrolyte layer 3 A negative electrode unit having 4 and 4 is obtained.

[0058] Then, the positive electrode unit and the negative electrode unit are alternately stacked and stacked so that one ends thereof do not coincide with each other, and a stacked body of an all-solid-state battery is manufactured. Regarding the positive electrode unit or the negative electrode unit placed at both ends in the stacking direction of the stack, the solid electrolyte layer 3 uses the outermost solid electrolyte layer 3 and the positive electrode unit or the negative electrode unit placed between them. For the unit, the solid electrolyte layer 3 uses the inter-layer solid electrolyte layer 38, respectively.

[0059] Although the manufacturing method is to manufacture a parallel type all-solid-state battery, the manufacturing method of the series-type all-solid-state battery is such that one end of the positive electrode layer 1 and one end of the negative electrode layer 2 are aligned. In other words, stacking may be performed without performing offset.

[0060] Furthermore, the produced laminates can be collectively pressed with a die press, a hot water isotropic press \), a cold water isotropic press (〇I), a hydrostatic press, etc. to improve the adhesion. .. It is preferable to apply pressure while heating, and for example, it can be performed at 40 to 95°.

[0061] The produced laminated body is cut into chips using a dicing device, and then de-baked and fired to produce an all-solid-state battery laminated body.

[0062] The manufactured laminated body 20 is placed on a ceramic table, and, for example, in a nitrogen atmosphere.

A sintered body is obtained by heating to 600° to 1000° and firing. The firing time is, for example, 0.1 to 3 hours. If it is a reducing atmosphere, firing may be performed in an argon atmosphere or a nitrogen-hydrogen mixed atmosphere instead of the nitrogen atmosphere.

[0063] Before the firing step, a binder removal treatment can be performed as a step different from the firing step.

By firing and decomposing the binder component contained in the laminate 20 before firing, firing is performed. 〇 2020/175 630 15 卩 (：171? 2020 /008067

It is possible to suppress the rapid decomposition of the binder component in the forming step. The debinding treatment is performed, for example, in a nitrogen atmosphere at a temperature in the range of 300° to 800°° for 0.1 to 10 hours. If it is a reducing atmosphere, the firing may be performed in an argon atmosphere or a nitrogen-hydrogen mixed atmosphere instead of the nitrogen atmosphere.

[0064] The sintered body may be placed in a cylindrical container together with an abrasive such as alumina and barrel-polished.

This makes it possible to chamfer the corners of the laminate. Alternatively, sandblast may be used for polishing. This method is preferable because only a specific portion can be removed.

[0065] (Terminal formation)

Attach the first external terminal 6 and the second external terminal 7 to the sintered laminated body 20 (sintered body). The first external terminal 6 and the second external terminal 7 are formed so as to be in electrical contact with the positive electrode current collector 1 and the negative electrode current collector 28, respectively. For example, the positive electrode current collector 18 and the negative electrode current collector 28 exposed from the side surface of the sintered body can be formed by a known means such as a slaughter method, a diving method, or a spray coating method.

When forming only on a predetermined part, masking or the like is performed with tape, for example.

Although the embodiments of the present invention have been described in detail above with reference to the drawings, the configurations and combinations thereof in each of the embodiments are merely examples, and the configurations of the configurations are not departing from the scope of the present invention. Additions, omissions, substitutions, and other changes are possible.

Example

[0067] [Example 1]

(Preparation of solid electrolyte layer paste)

Relative to _{trioctahedral} I 〇. ₃ chome丨7 (〇 4) 3 powder 1 0 0 parts ethanol 1 0 0 parts solvent were wet-mixed toluene 2 0 0 parts added in a ball mill. After that, as a binder, 1 part of polyvinyl butyral binder was added. 〇 2020/175 630 16 卩(：171? 2020/008067

Then, 4.8 parts of benzylputyl phthalate was added as a plasticizer and mixed to prepare a solid electrolyte layer paste.

This paste for solid electrolyte layer was formed into a sheet by a doctor blade method using a knife film as a base material to obtain an outermost solid electrolyte layer sheet and an interlayer solid electrolyte layer sheet. The outermost solid electrolyte layer sheet and the interlayer solid electrolyte layer sheet each had a thickness of 15.

(Production of Positive Electrode Active Material Layer Paste and Negative Electrode Active Material Layer Paste)

The positive electrode active material layer paste and the negative electrode active material layer paste for a the active material 1- 1 _{3 2} (〇 ₄₎ ₃ powder 1 0 0 parts ethylcellulose as a binder - a scan 1 5 parts solvent 6 parts by weight of dihydroterpineol was added and mixed-dispersed to prepare a positive electrode active material layer paste and a negative electrode active material layer paste.

(Production of Positive Electrode Current Collector Paste and Negative Current Collector Paste)

The V resinate, which is a coating agent, was dissolved in an organic solvent, and then ◯ powder was added, followed by thorough stirring. This mixed solution was dried to remove volatile components, and further heat-treated at 200° 〇 to obtain ◯ powder having V coated on the surface of ◯ powder. 〇The amount of V coating the surface of the powder is

○ It was set to be 0.0001 parts by weight in terms of metal with respect to 100 parts by weight. The coating powder obtained in this way and !_ 丨₃ ^ ₂ (〇 ₄ ) ₃ powder were mixed in a volume ratio of 60:40, and then 100 parts by weight of this mixed powder. To the parts, 10 parts by weight of ethyl cellulose as a binder and 50 parts by weight of dihydroterpineol as a solvent were added, and the mixture was kneaded and dispersed in a three-necked mixture to prepare a current collector paste.

[0070] (Production of paste for margin layer)

Beast for margin layer! -1 part of powder of ₃ ₃ 8 parts of 0.3 ₃ parts of ( ₄ ) ₃ to 15 parts of ethyl cellulose as a binder and 6 parts of dihydroterpineol as a solvent, and mixed. Dispersed to produce a margin layer space. 〇 2020/175 630 17 卩(：171? 2020/008067

[0071] (Preparation of electrode unit)

A positive electrode unit and a negative electrode unit were produced as follows.

On the above-mentioned solid electrolyte layer sheet, a screen for active material was printed with a thickness of 5 by screen printing. Next, the printed paste for active material was dried at 80 ^° 〇 for 5 minutes, and the paste for current collector was printed thereon with a thickness of 5 by screen printing. Next, the printed current collector paste was dried at 80 ^° for 5 minutes, and the active material paste was again printed thereon with a thickness of 5 by screen printing. The printed active material paste was dried at 80 ^° for 5 minutes, and then a margin layer paste was screen-printed on the area of the solid electrolyte sheet other than the electrode layer. The printed margin layer paste was dried at 80 ^° for 5 minutes to form a margin layer having almost the same height as the electrode layer, and then the Mending film was peeled off. Thus, an electrode in which an electrode layer (a positive electrode layer or a negative electrode layer) in which an active material layer/a current collector/an active material layer are stacked in this order and a margin layer are formed on a solid electrolyte layer sheet are formed. (Positive electrode or negative electrode) A unit sheet was obtained.

(Production of Laminate)

5 sheets of solid electrolyte layer sheets for the outermost solid electrolyte layer 3 are stacked, and 20 sheets of electrode units (10 sheets of positive electrode unit, 10 sheets of negative electrode unit) and 38 sheets of inter-layer solid electrolyte layer are stacked on it. They were stacked alternately so that they were interposed. At this time, the current collector paste layer of the odd-numbered electrode unit extends only to one end surface, and the current-source paste layer of the even-numbered electrode unit extends only to the opposite end surface. As described above, each unit was staggered and stacked. Six solid electrolyte layer sheets for the outermost solid electrolyte layer 3 were stacked on the stacked unit. Then, this was molded by thermocompression bonding and then cut to produce a laminated chip. Then, the laminated chips were simultaneously fired to obtain a laminated body 20. The co-firing is carried out in a nitrogen atmosphere rather than in an air atmosphere so that the current collector metal is less than 3 and the active material !_ 丨_{3 2} (90 ₄ ) ₃ is not oxidized or decomposed. The firing temperature was raised to 840 °C at ◯/hour, the temperature was maintained for 2 hours, and after cooling, it was naturally cooled.

(Preparation and Evaluation of All-Solid Secondary Battery) 〇 2020/175 630 18 卩 (：171? 2020 /008067

By a known method, a first external terminal and a second external terminal were attached to the sintered laminated body (sintered body) to fabricate an all solid state secondary battery.

The lead wire is attached to each of the first external terminal and the second external terminal, and the charge/discharge test is performed to measure the initial discharge capacity of the all-solid-state secondary battery and the cycle characteristics (capacity retention rate) after 100 cycles. did. The measurement conditions were 20 for both the current during charging and discharging, and 1.6 V and 0 V for the final voltages during charging and discharging, respectively. The results are shown in Table 1. The capacity at the first discharge was defined as the initial discharge capacity. The cycle characteristics (capacity retention rate) were calculated by dividing the discharge capacity at the 100th cycle by the initial discharge capacity.

The results are shown in Table 1.

[0074] For each one of the positive electrode current collector and the negative electrode current collector in the sintered laminate (sintered body),

When the weight ratio of <3 volume and V volume of each cross section was obtained, the average weight ratio of V volume to 0 volume was 0.001%.

[0075] For each of the positive electrode current collector and the negative electrode current collector in the sintered laminated body (sintered body), a 3 m IV! image of each cross section was obtained, and in each 3 m IV! image, By calculating the area of 20 sub-part images of and calculating the circle area conversion diameter of each sub-part image, the maximum diameter of the 40 circle area conversion diameters is 〇 1 (100 0 01). there were.

[0076] [Table 1]

[0077] [Comparative Example 1]

The base material for the current collector was manufactured as follows.

〇 against Li powder 1 0 0 parts by weight, the amount of V in terms of metal is 0.0 0 1 Weigh ₂ 〇 ₃ so that the parts by weight were mixed. The mixed powder thus obtained and 1_ 丨_{3 2} (〇 ₄ ) ₃ powder were mixed in a volume ratio of 60: 40, and then, to 100 parts by weight of the mixed powder, Ethyl cellulose as binder 〇 2020/175 630 19 卩(：171? 2020/008067

10 parts by weight and 50 parts by weight of dihydroterpineol as a solvent were added and kneaded and dispersed in a three-necked mixture to prepare a current collector paste.

An all-solid secondary battery was produced in the same manner as in Example 1 except that the production of the current collector base was performed as described above.

Table 1 shows the cycle characteristics (capacity retention rate) obtained using the all-solid-state secondary battery thus manufactured.

[0078] For each one of the positive electrode current collector and the negative electrode current collector in the sintered laminate (sintered body),! An analysis of each cross section was performed using _8 ichi ichi 1\/1 3 and found that only 〇ri was detected and V was not detected.

[0079] For each of the positive electrode current collector and the negative electrode current collector in the sintered laminated body (sintered body), a 3 m IV! image of each cross section was obtained, and each 3 m IV! image was obtained. Upon observation, no sub-image was confirmed.

[0080] As shown in Table 1, in Example 1 in which the current collector had a sub portion, the cycle characteristics were significantly improved as compared with Comparative Example 1 in which the current collector had no sub portion.

[0081] [Example 2_1 to Example 2-14]

In Examples 2-1 to 2-14, the coating agent resinate and

Basts for current collectors were produced in the same manner as in Example 1 except that 9, 8, and I resinates were used. Further, an all-solid secondary battery was produced in the same manner as in Example 1 by using this current collector paste.

Table 2 shows the cycle characteristics (capacity retention rate) obtained using each all-solid-state secondary battery prepared in this way.

[0082] [Example 2-15]

In Examples 2 to 15, V resin and a resin resinate were used as the coating agent, and the amount of V and powder coated on the surface of the powder was adjusted to 3 (100 parts by weight). On the other hand, a current collector base was prepared in the same manner as in Example 1 except that the total metal content was adjusted to 0.0001 parts by weight. Then, in the same manner as in Example 1, an all-solid-state secondary battery 〇 2020/175 630 20 boxes (: 171-1?2020/008067

Was produced. The secondary parts of the positive electrode current collector and the negative electrode current collector in the laminated body (sintered body) were analyzed by a 3-cylinder 1\/1 (scanning transmission electron microscope), and the secondary parts were It has been confirmed that it includes the following.

Table 2 shows the cycle characteristics (capacity retention rate) obtained using the all-solid-state secondary battery manufactured in this way.

[0083] [Example 2-16]

Similarly, in Examples 2 to 16, V resinate and IV! n resinate were used as the coating agent, and the amount of V and IV! coated on the surface of the powder was 3 (100 parts by weight). On the other hand, a current collector paste was produced in the same manner as in Example 1 except that the total amount was 0.001 parts by weight in terms of metal. Then, an all-solid-state secondary battery was manufactured in the same manner as in Example 1. Regarding the sub-portions of the positive electrode current collector and the negative electrode current collector in the laminated body (sintered body), 3 pcs. 0 3 Analysis was performed and it was confirmed that the sub-part contained V and IV! n.

[0084] [Example 2-17]

In Example 2-15, each sub-portion is formed of two kinds of elements, V and T, whereas in Example 2-17, a sub-portion consisting of V in the current collector is used. This is an example in which sub-parts made up of gadgets are scattered, dispersed, or mixed.

[0085] and Ding prepared V-coated Ding powder and Ding coating Ding powder coated on the surface of the Ding powder, respectively. V coating 〇 powder uses V resinate as a resinate, and the amount of V coated on the surface of powder powder is 3 (100 parts by weight relative to 3 parts by weight). The coating powder was prepared so that the amount of the coating powder was 1 part by weight, and the coating resin was a resinate, which was a resinate. It was prepared so that it would be 0.0001 parts by weight in terms of metal with respect to 100 parts by weight. 〇 2020/175 630 21 卩 (: 171-1? 2020 /008067

Parts and parts coating 0 powder 50 parts by weight are weighed and mixed <3 powder! -After mixing with _{3 2} (〇 ₄ ) ₃ powder in a volume ratio of 60: 40, 100 parts by weight of this mixed powder was mixed with 10 parts by weight of ethyl cellulose as a binder. Then, 50 parts by weight of dihydroterpineol was added as a solvent, and the mixture was kneaded and dispersed in a three-necked mixture to prepare a current collector paste. Further, an all-solid-state secondary battery was manufactured in the same manner as in Example 1 using this current collector base material. Analysis was performed on the sub-portions of the positive electrode current collector and the negative electrode current collector in the laminated body (sintered body), and the analysis was performed for 3 tools 1\/1 _ _ 0 0 3. It was confirmed that and were scattered, dispersed or mixed.

[0086] [Example 2 _ 18]

In Example 2-16, each sub-portion is formed by two elements of V and 1\/1 _n , whereas in Example 2-18, V is contained in the current collector. In this example, sub-parts and sub-parts consisting of IV! n are scattered, dispersed, or mixed.

[0087] and 1\/1 n were prepared as V-coated powder and IV!n-coated powder coated with the surface of the powder. V coating 〇 powder uses V resinate as a resinate, and the amount of V coated on the surface of powder powder is 3 (100 parts by weight relative to 3 parts by weight). It was prepared so that the amount would be 1 part by weight IV!n coating ○ powder was used as the coating agent resinate.

Using resinate, it was prepared so that the amount of IV! coated on the surface of the powder was (0.01 parts by weight in terms of metal with respect to 100 parts by weight of V. V! coating) 50 parts by weight of the re-powder and 50 parts by weight of the IV! _n coating were weighed out, and the mixture <3 re-powder powder and !- _{3 2} (〇 ₄ ) ₃ powder were mixed in a volume ratio of 6 0 : 40, and then mixed with 100 parts by weight of this mixed powder, add 10 parts by weight of ethyl cellulose as a binder and 50 parts by weight of dihydroterpineol as a solvent, and add three parts Kneading and dispersing with a solvent to prepare a current collector paste. 〇 2020/175 630 22 卩 (：171? 2020 /008067

An all-solid secondary battery was prepared in the same manner as in Example 1 using the body paste. _ 3 analysis of the sub-portions of the positive electrode current collector and the negative electrode current collector in the laminate (sintered body) was performed, and the sub-portion consisting of V and the sub-portion consisting of IV! It was confirmed that they were scattered or dispersed or mixed.

[0088] [Table 2]

[0089] As shown in Table 2, although the cycle characteristics were different depending on the type of the element (second element) of the secondary portion of the current collector, all of Examples 2-1 to 2-18 were collected. Compared to Comparative Example 1 in which the electric body does not have a sub portion, the cycle characteristics are greatly improved. Of these, the element of the sub-part is IV! 1\1 ___○, ", 0 6, ,__ V and Ding 1, 〇 2020/175 630 23 卩 (: 171? 2020 /008067

V and IV! n, mixed with V and G, and mixed V and IV! n have high cycle characteristics of 90% or more. Among these, the secondary element is Mn, 1\1 and V and D! In the case of V and IV! n, it was found that the cycle characteristics were particularly high at 92% or more.

[0090] [Example 3 _ 1 to Example 3-10]

In Example 3 _ 1 to Example 3 _ 10, the amount of V coated on the surface of powder was 0.0002, 0. 01, 0. 1 in terms of metal with respect to 100 parts by weight of 0. , 0.4, 0.8, 1, 5, 10, 10, 15 and 20 parts by weight were prepared in the same manner as in Example 1 to prepare a base current collector. Further, an all-solid secondary battery was manufactured in the same manner as in Example 1 by using this current collector paste.

In each example, as in Example 1,! _ _ I 〇 _1 \/13 was used to obtain the weight ratio of 〇li amount and V amount. The average weight ratio of V amount to <3li amount was as shown in Table 3.

Table 3 shows the cycle characteristics (capacity retention rate) obtained using each all-solid-state secondary battery.

[0091] [Table 3]

[0092] As shown in Table 3, in all of Examples 3_1 to 3-6, the cycle characteristics were significantly improved as compared with Comparative Example 1 in which the current collector did not have a sub portion. Of these, the vice part 〇 2020/175 630 24 卩 (：171? 2020 /008067

When the weight ratio of the secondary part is 0.001%, the cycle characteristic is 92%, and the weight ratio of the secondary part is 0.001%. It was found that the cycle characteristics were high when the weight ratio of the above was 0.002% or more and 20% or less, especially when it was 0.001% or more and 0.01% or less. It was found that when the weight ratio of the auxiliary part is 15% or less, the cycle characteristics are as high as 75% or more, and when the weight ratio of the auxiliary part is 1% or less, the cycle characteristics are as high as 80% or more.

[Example 4 _ 1]

The circle area conversion diameter of the sub-part can be adjusted by adjusting the amount of the sub-part element (second element) coated on the powder surface.

○ The amount of V coated on the surface of the powder was (1% by weight in terms of metal, based on 3 parts by 100 parts by weight, in the same manner as in Example 1). I obtained the powder coated with V on the surface of /.

Weighed 100 parts by weight of uncoated <3 powder and 1 part by weight of V-coated powder, mixed and then mixed these <3 powder and !_ 1 _{3 2} (0 ₄ ) ₃ powder was mixed in a volume ratio of 60: 40, and then 100 parts by weight of this mixed powder, 10 parts by weight of ethyl cellulose as a binder and 5 parts by weight of dihydroterpineol as a solvent. 0 parts by weight was added, and the mixture was kneaded and dispersed with a triple neck to prepare a current collector paste. Further, using this current collector paste, an all-solid-state secondary battery was prepared in the same manner as in Example 1.

Table 4 shows the cycle characteristics (capacity retention rate) obtained using the fabricated all-solid-state secondary battery.

[0094] For each one of the positive electrode current collector and the negative electrode current collector in the sintered laminate (sintered body), in the same manner as in Example 1, a 3xIV! image of each cross section was obtained. As a result of calculating the circle area conversion diameter of each sub-image, the maximum circle-area conversion diameter of the sub-image was ◯0.01 (10000).

[0095] [Example 4_2 to Example 4_6]

In Examples 4 — 2 to 4 — 6, in Example 4 — 1, uncoated 〇 2020/175 630 25 卩 (：171? 2020 /008067

For current collector, except that the amount of V coating powder is 5, 20, 30, 50, 100 parts by weight per 100 parts by weight of Beast was prepared. Further, an all-solid secondary battery was produced in the same manner as in Example 1 by using this current collector paste.

Table 4 shows the cycle characteristics (capacity maintenance rate) obtained using each of the fabricated all-solid-state secondary batteries.

[0096] Regarding Examples 4_2 to 4_6, the positive electrode current collector and the negative electrode current collector each in the sintered laminate (sintered body) were processed in the same manner as in Example 1. Then, we obtained 3M 1\/1 images of each cross section and calculated the circle-area conversion diameter of each sub-part image.The maximum circle-area conversion diameter of each sub-part image was 0. 05 (50 nm), 〇.

(

2001^111), 〇0.3 〇! (30 〇1^〇1), 〇0.5 (50 〇1^〇1), 1

^ 111.

[0097] [Table 4]

[0098] As shown in Table 4, in all of Examples 4_1 to 4-6, the cycle characteristics were greatly improved as compared with Comparative Example 1 in which the current collector did not have a sub portion. In particular, the cycle characteristics are higher when the maximum area-converted circle area is 0.01 to 0.3, and the cycle characteristics of Example 1 with a maximum diameter of 0.1 are 96%. It was found that the cycle characteristics were even higher when the maximum diameter was 0.05 to 0.2.

[0099] [Example 5_1 to Example 5-6] 〇 2020/175 630 26 卩 (：171? 2020 /008067

Example 5 _ 1 to Example 5 _ 6 are the same as Example 1 except that the current collector metal (the main part of the current collector) was 1\1 and was 6, 8, ₉ , 8 and 1, respectively. In the same manner, a current collector base was prepared. Further, an all-solid secondary battery was manufactured in the same manner as in Example 1 using this current collector paste.

Table 5 shows the cycle characteristics (capacity retention rate) obtained using the fabricated all-solid-state secondary battery.

[0100] [Table 5]

[0101] As shown in Table 5, in all of Examples 5_1 to 5-6, the cycle characteristics were significantly improved as compared with Comparative Example 1 in which the current collector did not have a sub portion.

Industrial availability

[0102] According to the present invention, it is possible to provide an all-solid-state secondary battery having good cycle characteristics.

Explanation of symbols

[0103] 1 Positive electrode layer

1 8 Positive electrode current collector

1 8 3 Main part

1 Hatsune Sub-part

1 Min Positive electrode active material layer

2 Negative electrode layer

2 8 Negative electrode current collector

2 8 3 Main part 〇 2020/175 630 27 卩 (: 171? 2020 /008067

2 Hatsune

2 Negative electrode active material layer

3 Solid electrolyte layer

6 1st external terminal

7 Second external terminal

20 stacks

100 Solid-state secondary battery

Claims

〇 2020/175 630 28 卩(：171? 2020/008067 Claims

[Claim 1] A positive electrode layer including a positive electrode current collector and a positive electrode active material layer, a negative electrode layer including a negative electrode current collector and a negative electrode active material layer, and a solid electrolyte layer including a solid electrolyte, A positive electrode layer and the negative electrode layer form a laminated body in which solid electrolyte layers are alternately laminated,

The positive electrode current collector and the negative electrode current collector each include a main part containing a first element as a main component and a sub-part containing a second element which is an element different from the first element. Next battery.

[Claim 2] The first element is 〇ri, 1\!

An element selected from the group consisting of I,

The second element is, 〇 Li, 1 \ 1 tooth eight _9, Hachiri,,

V, just

○○、「, 3 I _% 0 6 _%

And the all-solid secondary battery according to claim 1, which is one or more elements selected from the group consisting of 8I.

[Claim 3] The weight ratio of the second element to the first element is within the range of 0.002% or more and 20% or less, and the total solid according to claim 1 or 2. Secondary battery.

[Claim 4] The circle area conversion diameter of the sub-part is 0.5 or less, wherein the all-solid secondary battery according to any one of claims 1 to 3;

Here, the circle area conversion diameter is calculated as ¢1 = {^ / %) ( ² ) X 2 when the area of the sub-portion in the 3rd 1\/1 image is 3.

[Claim 5] The all-solid secondary battery according to any one of claims 1 to 4, wherein the sub-portion is obtained by allowing the main portion to deviate an element containing the second element.