CN117638205A

CN117638205A - Negative electrode-solid electrolyte proton assembly, all-solid secondary battery including the same, and method of manufacturing all-solid secondary battery

Info

Publication number: CN117638205A
Application number: CN202311108261.0A
Authority: CN
Inventors: 金世元; 高东秀; 金瑢洙; 金柱植; 尹钾仁
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2022-08-31
Filing date: 2023-08-30
Publication date: 2024-03-01

Abstract

The present invention relates to a negative electrode-solid electrolyte proton assembly, an all-solid secondary battery including the same, and a method of manufacturing the all-solid secondary battery. A negative electrode-solid electrolyte proton assembly for an all-solid secondary battery includes: a negative electrode current collector, a first negative electrode active material layer disposed on the negative electrode current collector, and a middle disposed on the first negative electrode active material layer and opposite to the negative electrode current collectorA layer, and a solid electrolyte disposed on the intermediate layer and opposite the first anode active material layer, wherein the first anode active material layer may include a mixture of a compound of formula 1 and a compound of formula 2, or a combination thereof, the intermediate layer includes a third metal material, a lithium oxide, or a combination thereof, the third metal material includes a third metal oxide, an oxide including a third metal and lithium, or a combination thereof, and the third metal is an element of groups 2 to 15: 1Li _x M1 _y 2M2 _a N _b 。

Description

Negative electrode-solid electrolyte proton assembly, all-solid secondary battery including the same, and method of manufacturing all-solid secondary battery

Cross reference to related applications

The present application is based on and claims priority and ownership benefits from korean patent application No. 10-2022-01010101251, filed at the korean intellectual property office at month 8 of 2022, and korean patent application No.10-2023-0098940, filed at month 7 of 2023.

Technical Field

The present disclosure relates to a negative electrode-solid electrolyte proton assembly, an all-solid secondary battery including the same, and a method of preparing the all-solid secondary battery.

Background

Recently, due to industrial demands, batteries having high energy density and excellent safety have been actively developed. For example, lithium ion batteries have been put into practical use not only in the fields of information-related devices and communication devices, but also in the field of automobiles. In the automotive field, safety is particularly important as it is life-related.

Lithium ion batteries currently available on the market use electrolyte solutions containing flammable organic solvents, and therefore, there is a possibility that they overheat and catch fire when a short circuit occurs. Accordingly, all-solid secondary batteries using a solid electrolyte have been proposed.

Since the all-solid secondary battery does not use a flammable organic solvent, the possibility of causing fire or explosion can be greatly reduced even if a short circuit occurs. Therefore, such an all-solid secondary battery can greatly improve safety as compared to a lithium ion battery using an electrolyte solution.

In order to increase the energy density of such an all-solid secondary battery, lithium may be used as a negative electrode active material. For example, it is known that the specific capacity (capacity per unit mass) of lithium metal is about 10 times that of graphite which is generally used as a negative electrode active material. Therefore, using lithium as the negative electrode active material can increase the capacity while reducing the total solid secondary battery.

However, in a structure using a solid electrolyte as an electrolyte and lithium as a negative electrode active material, lithium metal may be unevenly deposited on the surface of the solid electrolyte during a charging process, which may induce cracks (crazes) in the solid electrolyte. Cracks in the solid electrolyte may induce short circuits in the all-solid secondary battery. Thus, there remains a need for improved all-solid secondary batteries.

Disclosure of Invention

Provided is a negative electrode-solid electrolyte proton assembly for an all-solid secondary battery, in which short circuits are prevented and the rate capacity and life characteristics are improved.

Provided are an all-solid secondary battery having improved battery performance by including the anode-solid electrolyte proton assembly for an all-solid secondary battery, and a method of manufacturing the all-solid secondary battery.

Additional aspects will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the embodiments presented herein.

In accordance with one aspect of the present disclosure,

the anode-solid electrolyte proton assembly includes: a negative electrode current collector, a first negative electrode active material layer disposed on the negative electrode current collector, an intermediate layer disposed on the first negative electrode active material layer and opposite to the negative electrode current collector, and a solid electrolyte disposed on the intermediate layer and opposite to the first negative electrode active material layer, wherein the first negative electrode active material layer may include a mixture of a compound of formula 1 and a compound of formula 2, or a combination thereof,

1 (1)

Li _x M1 _y

Wherein in formula 1, M1 is a first metal and is an element capable of forming a compound or alloy with lithium and oxygen, and

x is more than or equal to 0 and less than or equal to 20, y is more than or equal to 1 and less than or equal to 10,

2, 2

M2 _a N _b

Wherein in formula 2, M2 is a second metal and is lithium, an element capable of forming a compound or alloy with lithium and nitrogen, or a combination thereof, and

a is more than or equal to 1 and less than or equal to 15, b is more than or equal to 1 and less than or equal to 10,

wherein the intermediate layer comprises a third metal material, lithium oxide, or a combination thereof, and

The third metal material includes a third metal oxide, an oxide including a third metal and lithium, or a combination thereof, wherein the third metal is a group 2 to 15 element.

The compound of formula 1 is Li ₃ Al、Li ₂ Zn、Li ₄ Sn, li in which x is 1.ltoreq.3 and y is 1.ltoreq.3 _x Si _y Li, wherein x is 1-3 and y is 1-3 _x Ge _y Li, wherein x is 1-3 and y is 1-3 _x Cu _y Wherein 0 is<x<Li of 5 _x Sn, 0 therein<x<Li of 5 _x Zn, 0 therein<x<Li of 5 _x Al, 0 therein<x<Li of 4 _x Sb, 0 therein<x<Li of 5 _x Si, 0 therein<x<Li of 5 _x Au, 0 therein<x<Li of 10 _x Ag. Wherein 0 is<x<Li of 5 _x In, 0 therein<x<Li of 5 _x Bi. Wherein 0 is<x<Li of 5 _x Ga. Wherein 0 is<x<Li of 5 _x Te of 0<x<Li of 5 _x Ge. Wherein 0 is<x<L of 7 _ix Mg, or a combination thereof, and wherein the compound of formula 2 is Li ₃ N, al in which a is 1-3 and b is 1-4 _a N _b Zn with a being equal to or more than 1 and equal to or less than 3 and b being equal to or less than 1 and equal to or less than 4 _a N _b Sn, wherein a is 1-3 and b is 1-4 _a N _b Si in which a is 1.ltoreq.a.ltoreq.3 and b is 1.ltoreq.b.ltoreq.4 _a N _b Ge with a being equal to or more than 1 and equal to or less than 3 and b being equal to or less than 1 and equal to or less than 4 _a N _b Cu in which a is 1-3 and b is 1-4 _a N _b In, wherein a is 1.ltoreq.a.ltoreq.3 and b is 1.ltoreq.b.ltoreq.4 _a N _b Ga, wherein a is 1-3 and b is 1-4 _a N _b Ti in which a is 1-3 and b is 1-4 _a N _b Zr with a being equal to or more than 1 and equal to or less than 3 and b being equal to or less than 1 and equal to or less than 4 _a N _b Nb in which a is 1-3 and b is 1-4 _a N _b Or a combination thereof, or wherein the compound of formula 2 is Li ₃ N、AlN、Zn ₃ N ₂ 、Sn ₃ N ₄ 、Si ₃ N ₄ 、Ge ₃ N ₄ 、Cu ₃ N, or a combination thereof.

The first anode active material layer has a thickness in a range of about 1 nm to about 100 μm.

The lithium oxide may be, for example, li ₂ O。

In the formula 1, x is more than or equal to 1 and less than or equal to 18, x is more than or equal to 1 and less than or equal to 16, x is more than or equal to 1 and less than or equal to 15, x is more than or equal to 1 and less than or equal to 14, x is more than or equal to 1 and less than or equal to 12, x is more than or equal to 1 and less than or equal to 10, x is more than or equal to 1 and less than or equal to 8, x is more than or equal to 1 and less than or equal to 5, or x is more than or equal to 1 and less than or equal to 3, and y is more than or equal to 1 and less than or equal to 3. The volume of the first anode active material layer after charging the all-solid secondary battery may be 200% or less of the volume of the first anode active material layer after discharging.

The second anode active material layer may be further formed as a precipitation layer during charging of the all-solid secondary battery, during disposing the second anode active material layer between the current collector and the first anode active material, or during both the charging and disposing the second anode active material layer between the current collector and the first anode active material. The second anode active material layer may include lithium metal, a lithium alloy, or a combination thereof.

According to another aspect of the present disclosure, an all-solid secondary battery includes a positive electrode and a negative electrode-solid electrolyte proton assembly disposed on the positive electrode, wherein the solid electrolyte may be between the positive electrode and the negative electrode.

The first metal in the first anode active material layer may form an alloy with lithium during charging of the all-solid secondary battery.

In accordance with another aspect of the present disclosure,

the method for preparing the all-solid secondary battery comprises the following steps: the positive electrode is provided in such a way that,

the solid electrolyte is provided on the positive electrode,

disposing the intermediate layer on a first surface of the solid electrolyte, the first surface being opposite to a second surface of the solid electrolyte on which the positive electrode is disposed,

disposing the first anode active material layer on the intermediate layer and opposite to the solid electrolyte, and disposing the anode current collector on the first anode active material layer opposite to the intermediate layer to produce the all-solid secondary battery,

wherein the first anode active material layer may include a mixture of a compound of formula 1 and a compound of formula 2, a complex of a compound of formula 1 and a compound of formula 2, or a combination thereof,

1 (1)

Li _x M1 _y

Wherein in formula 1, M1 is the first metal and may be an element capable of forming a compound or alloy with lithium and oxygen, and

2, 2

M2 _a N _b

Wherein in formula 2, M2 is a second metal and may be lithium, an element capable of forming a compound or alloy with lithium and nitrogen, or a combination thereof, and

A is more than or equal to 1 and less than or equal to 15, and b is more than or equal to 1 and less than or equal to 10.

Providing the intermediate layer and the first anode active material layer may include

Depositing the first metal on the solid electrolyte in a nitrogen atmosphere to form a first layer including a first metal nitride layer, an

The first layer is brought into contact with lithium,

the all-solid secondary battery is charged to supply lithium to the first layer,

heat treating the first layer, or a combination thereof,

to simultaneously form the intermediate layer and the first anode active material layer using the first layer.

Disposing the first metal on the solid electrolyte in an oxygen atmosphere to form a second layer including a first metal oxide layer and thereby form the intermediate layer, an

The first metal is deposited on the second layer in a nitrogen atmosphere to form a first layer including a first metal nitride layer and thereby form the first anode active material layer.

The method of manufacturing the all-solid secondary battery may further include: a second anode active material layer is provided between the anode current collector and the first anode active material layer, and the second anode active material layer may include a fourth metal.

The second anode active material layer may be formed as a precipitation layer during charging of the all-solid secondary battery, during disposing (e.g., bonding) the anode current collector on the first anode active material layer, or both the charging and disposing the anode current collector on the first anode active material layer, and the second anode active material layer may include lithium metal, a lithium alloy, or a combination thereof.

Also disclosed is a negative electrode-solid electrolyte proton assembly for an all-solid secondary battery, comprising:

a first anode active material layer;

an intermediate layer disposed on the first anode active material layer; and

a solid electrolyte disposed on the intermediate layer and opposite to the first anode active material layer,

wherein the first anode active material layer comprises a mixture of a compound of formula 1 and a compound of formula 2, a complex of a compound of formula 1 and a compound of formula 2, or a combination thereof,

1 (1)

Li _x M1 _y

2, 2

M2 _a N _b

the third metal material comprises a third metal oxide, an oxide comprising a third metal and lithium, or a combination thereof,

wherein the third metal is a group 2 to 15 element.

Also disclosed is a negative electrode for an all-solid secondary battery, comprising:

a negative electrode current collector;

a first anode active material layer disposed on the anode current collector;

an intermediate layer disposed on the first anode active material layer and opposite to the anode current collector;

1 (1)

Li _x M1 _y

Wherein in formula 1, M1 is a first metal and is an element capable of forming a compound or alloy with lithium and oxygen, and 0.ltoreq.x.ltoreq.20 and 1.ltoreq.y.ltoreq.10,

2, 2

M2 _a N _b

Wherein in formula 2, M2 is a second metal and is lithium, an element capable of forming a compound or alloy with lithium and nitrogen, or a combination thereof, and 1.ltoreq.a.ltoreq.15 and 1.ltoreq.b.ltoreq.10,

wherein the intermediate layer comprises a third metal material, a lithium oxide, or a combination thereof, and the third metal material comprises a third metal oxide, an oxide comprising a third metal and lithium, or a combination thereof, wherein the third metal is a group 2 to 15 element.

The method of manufacturing the all-solid secondary battery further includes: a second anode active material layer is provided between the anode current collector and the first anode active material layer, wherein the second anode active material layer comprises a fourth metal material, and the fourth metal material is a fourth metal, lithium, and a lithium alloy of the fourth metal, or a combination thereof, wherein the fourth metal is a group 2 to 15 element.

The second anode active material layer is formed as a precipitation layer during charging, during disposing an anode current collector on the first anode active material layer, or during both the charging and disposing an anode current collector on the first anode active material layer, and the second anode active material layer is lithium metal, a lithium alloy, or a combination thereof.

Drawings

The above and other aspects, features, and advantages of some embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings in which:

fig. 1 is a view showing the structure of an embodiment of a negative electrode-solid electrolyte proton assembly of an all-solid secondary battery;

fig. 2A shows the result of Scanning Electron Microscope (SEM) analysis of the all-solid secondary battery prepared in example 1 after charging;

FIG. 2B is an enlarged view of a portion of FIG. 2A;

fig. 2C to 2E show the results of scanning electron microscopy and energy dispersive spectroscopy (SEM-EDS) analysis of the solid electrolyte/intermediate layer/first anode active material layer/second anode active material layer laminate prepared in example 1, wherein fig. 2C is a tin (Sn) map (face scan), fig. 2D is a nitrogen (N) map, and fig. 2E is an oxygen (O) map;

FIG. 3A is an imaginary resistance (Z', ohm cm) ² ) Resistance to real part (Z', ohm cm) ² ) Is shown an all-solid-two including a negative electrode-solid electrolyte proton assembly according to example 1Impedance characteristics of the secondary battery;

FIG. 3B is a potential (volts, relative to Li) ⁺ Per unit area (mAh/cm) ² ) And shows the result of charging and discharging of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to example 1;

FIG. 3C is a graph of capacity per unit area (mAh/cm ² ) A graph for cycle showing life characteristics of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to example 1;

fig. 4A to 4D are each an image showing the result of Transmission Electron Microscope (TEM) -Energy Dispersive Spectrometry (EDS) mapping analysis for Li, sn, O, and N, respectively, of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to example 1;

Fig. 5A to 5D are each an image showing the result of TEM-Electron Energy Loss Spectroscopy (EELS) mapping analysis of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to example 1, wherein fig. 5A shows Li response, fig. 5B shows Sn response, fig. 5C shows O response, and fig. 5D shows N response;

fig. 6A to 6E are each a graph showing the result of TEM-EDS mapping analysis of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to example 2, wherein fig. 6A is a secondary electron image, fig. 6B is a HAADF image, fig. 6C is a Cu map, fig. 6D is an N map, and fig. 6E is an O map;

FIG. 7A is an imaginary resistance (Z', ohm cm) ² ) And real part resistance (Z', ohm cm) ² ) Is shown, which shows the impedance characteristics of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to example 2;

FIG. 7B is a potential (volts, vs. Li) ⁺ Per unit area (mAh/cm) ² ) And shows the results of charge and discharge analysis of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to example 2;

FIG. 7C is a graph of capacity per unit area (mAh/cm ² ) A graph of the cycle showing a negative electrode-solid electrolyte proton assembly according to example 2 Life characteristics of all-solid secondary batteries;

FIG. 7D is an imaginary resistance (Z', ohm cm) ² ) Resistance to real part (Z', ohm cm) ² ) Is shown, which shows the impedance characteristics of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to example 3;

fig. 8A to 8C are each a graph of intensity (arbitrary unit, a.u.) versus binding energy (electron volt, eV), which shows the result of X-ray photoelectron spectroscopy (XPS) analysis with respect to the formation of the first anode active material layer after the reaction of Li with CuNx, which is a precursor for forming the first anode active material layer according to example 2, wherein fig. 8A, 8B, and 8C are each XPS analysis results for Li, cu, and N, respectively;

FIG. 9A is an imaginary resistance (Z', ohm cm) ² ) And real part resistance (Z', ohm cm) ² ) Is a graph showing the impedance characteristics of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to comparative example 1;

FIG. 9B is a potential (volts, vs. Li) ⁺ Per unit area (mAh/cm) ² ) Is a graph showing the charging and discharging results of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to comparative example 1;

FIG. 10A is an imaginary resistance (Z', ohm cm) ² ) And real part resistance (Z', ohm cm) ² ) Is a graph showing the impedance characteristics of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to comparative example 2;

FIG. 10B is a plot of potential (volts versus Li+/Li) versus capacity per unit area (mAh/cm ² ) Is a graph showing the charging and discharging results of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to comparative example 2;

FIG. 11A is an imaginary resistance (Z', ohm cm) ² ) And real part resistance (Z', ohm cm) ² ) Is a graph showing the impedance characteristics of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to comparative example 3;

FIG. 11B is a potential (volts, vs. Li) ⁺ Per unit area (mAh/cm) ² ) Is a graph showing the charging and discharging results of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to comparative example 3;

FIG. 12A is an imaginary resistance (Z', ohm cm) ² ) And real part resistance (Z', ohm cm) ² ) Is a graph showing the impedance characteristics of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to comparative example 4;

FIG. 12B is a plot of potential (volts versus Li+/Li) versus capacity per unit area (mAh/cm ² ) Is a graph showing the charging and discharging results of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to comparative example 4;

FIG. 13 is a potential (volts, vs. Li) ⁺ Per unit area (mAh/cm) ² ) Shows the charging and discharging results of an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to comparative example 5; and

fig. 14 is a schematic view showing the structure of an all-solid secondary battery according to an embodiment.

Detailed Description

Reference will now be made in detail to the embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as limited to the descriptions set forth herein. Accordingly, the embodiments are described below to illustrate aspects by referring only to the drawings. These embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. The expression "at least one of …" modifies the entire list of elements when before or after the list of elements, without modifying individual elements in the list.

It will be understood that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements may be present therebetween. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present.

It will be understood that, although the terms "first," "second," "third," etc. may be used herein to describe various elements, components (assemblies), regions, layers and/or sections, these elements, components (assemblies), regions, layers or sections should not be limited by these terms. These terms are only used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a "first element," "component (assembly)", "region," "layer" or "section" discussed below could be termed a second element, component (assembly), region, layer or section without departing from the teachings herein.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. As used herein, the indefinite article "a" or "an" does not mean limitation on the amount of the "at least one of the" and "… …" and is intended to include both the singular and the plural, unless the context clearly indicates otherwise. For example, unless the context clearly indicates otherwise, "an element" has the same meaning as "at least one element(s)". The term "at least one" should not be construed as limiting the term "one". "or" means "and/or". As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, regions, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, regions, integers, steps, operations, elements, components, and/or groups thereof.

Furthermore, relative terms such as "lower" or "bottom" and "upper" or "top" may be used herein to describe one element's relationship to another element as illustrated in the figures. It will be understood that relative terms are intended to encompass different orientations of the device in addition to the orientation depicted in the figures. For example, if the device in one of the figures is turned over, elements described as being on the "lower" side of additional elements would then be oriented on the "upper" side of the additional elements. Thus, the term "lower" may include both "lower" and "upper" orientations, depending on the particular orientation of the figure. Similarly, if the device in one of the figures is turned over, elements described as "under" or "beneath" additional elements would then be oriented "over" the additional elements. Thus, the term "under" or "under" may encompass both an orientation of above and below.

Endpoints within the range may be independently combined. As used herein, "about" or "approximately" includes the stated values and is meant to be within an acceptable range of deviation from the particular values as determined by one of ordinary skill in the art in view of the measurements in question and the errors associated with the measurement of the particular quantities (i.e., limitations of the measurement system). For example, "about" means within one or more standard deviations, or within ±30%, 20%, 10% or 5%, relative to the stated values.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the present disclosure and relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Embodiments are described herein with reference to cross-sectional views as schematic illustrations of idealized embodiments. In this way, deviations from the shape of the figures as a result of, for example, manufacturing techniques and/or tolerances, will be expected. Thus, the embodiments described herein should not be construed as limited to the particular shapes of regions as illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an area illustrated or described as flat may typically have rough and/or nonlinear features. Moreover, the sharp corners illustrated may be rounded. Accordingly, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a region and are not intended to limit the scope of the claims.

Hereinafter, a negative electrode-solid electrolyte proton assembly for an all-solid secondary battery, an all-solid secondary battery including the same, and a method of manufacturing the same will be described in further detail with reference to the accompanying drawings. Like reference numerals in the drawings denote like components, and the dimensions of the components in the drawings may be exaggerated for clarity and convenience of illustration. Furthermore, the embodiments described herein are for illustrative purposes only, and various changes in form and detail may be made therein.

In order to provide an all-solid secondary battery that can reduce interface resistance between a negative electrode and a solid electrolyte while preventing cracking of the solid electrolyte, an all-solid secondary battery having a structure including a negative electrode in which a lithium metal layer is in contact with a negative electrode current collector has been proposed; a negative electrode active material layer including a carbonaceous active material disposed on the lithium metal layer; and a contact layer including a metal and formed between the anode active material layer and the solid electrolyte or a structural body of an anode oxide protective layer applied thereto.

However, in such an all-solid secondary battery, the contact layer in contact with the solid electrolyte includes only a metal, and thus, electron conduction is not prevented, resulting in a short circuit caused by precipitation of lithium in the solid electrolyte. In addition, when reacting with lithium during charge and discharge of the all-solid secondary battery, side reactions such as aggregation or volume expansion may occur, resulting in deterioration of life characteristics. Further, when an oxide protective layer is used, the conductivity of lithium ions is low, so that the oxide protective layer can function as a resistance (resistance) element when the battery is driven during charge and discharge.

In order to solve the above-described problems, the present inventors provide a negative electrode-solid electrolyte proton assembly comprising: a negative electrode current collector; a first anode active material layer disposed on the anode current collector; an intermediate layer disposed on the first anode active material layer and opposite to the anode current collector; and a solid electrolyte provided on the intermediate layer and opposite to the first anode active material layer,

1 (1)

Li _x M1 _y

2, 2

M2 _a N _b

Here, the expression "metal" as used herein includes metals and semi-metals.

In formula 1, x and y may each be independently 1.ltoreq.x.ltoreq.3 and 1.ltoreq.y.ltoreq.3, and in formula 2, a and b may each be independently 1.ltoreq.a.ltoreq.3 and 1.ltoreq.b.ltoreq.4.

The first anode active material layer may further include a compound represented by formula 3:

3

M2 _a O _b

Wherein in formula 3, the second metal (M2) may be lithium, an element capable of forming a compound or alloy with lithium and nitrogen, or a combination thereof, and

a is more than or equal to 1 and less than or equal to 20, and b is more than or equal to 1 and less than or equal to 10.

In formula 3, M2 may be, for example, li. In addition, a is more than or equal to 1 and less than or equal to 3, and b is more than or equal to 1 and less than or equal to 4.

Fig. 1 is a schematic view of the structure of an embodiment of a laminate of a negative electrode-solid electrolyte proton assembly for an all-solid secondary battery.

The first anode active material layer 23 may be between the solid electrolyte 30 and the anode current collector 21. The intermediate layer 22 may be located between the solid electrolyte 30 and the first anode active material layer 23, and the second anode active material layer 24 may be located between the first anode active material layer 23 and the anode current collector 21.

The first anode active material layer 23 may include the following as anode active materials: a mixture of a compound of formula 1 and a compound of formula 2 as a nitride, a complex of a compound of formula 1 and a compound of formula 2, or a combination thereof. Accordingly, the first anode active material layer 23 contains the following materials: which upon reaction with lithium can form compounds with rapid lithium ion movement and provide uniform and rapid lithium ion movement channels.

When the anode active material is made of only a metal material, durability of the anode may not be maintained due to aggregation or volume expansion during reaction with lithium during charge and discharge of the battery, and deterioration may occur, resulting in deterioration of high rate characteristics due to slow lithium ion movement. In addition, movement of electrons may not be effectively prevented, and thus, electrons may flow through the solid electrolyte, resulting in a short circuit in the battery.

However, the first anode active material layer 23 according to the embodiment may further include a nitride and a compound of formula 1. When the first anode active material layer contains only the compound of formula 1, it is difficult to maintain the durability of the anode due to volume change. However, the first anode active material layer according to the embodiment may contain the nitride compound of formula 2 to maintain the structure during charge and discharge. Further, by alleviating the pressure applied to the solid electrolyte by alleviating the volume expansion of the anode during charge and discharge, the short-circuiting of the solid electrolyte due to the indicated pressure can be delayed. Further, since the first anode active material layer may contain nitride, it provides greater lithium ion conductivity than the anode active material layer containing the anode active material and oxide. Further, the first anode active material layer may serve as a buffer layer that may buffer volume expansion caused by lithium intercalation and deintercalation during charge and discharge.

Since the intermediate layer 22 may contain the third metal oxide, electron conduction in the solid electrolyte may be prevented. Since the intermediate layer 22 may contain an oxide composition similar to the solid electrolyte (e.g., oxide-based (i.e., oxide) solid electrolyte), the binding force of the intermediate layer 22 to the solid electrolyte 30 may be excellent. Due to the thin thickness of the intermediate layer 22, rapid lithium movement in the anode can be ensured because the intermediate layer 22 does not act as a resistance (resistance) element against movement of lithium ions. Further, lithium introduced through the solid electrolyte during charging is induced to rapidly diffuse through the metal layer, and thus, even when charging and discharging are repeated, contact between the solid electrolyte 30 and the first anode active material layer 23 can be improved, and the shape can be unchanged. Therefore, the intermediate layer 22 may help to maintain durability, and may reduce interface resistance between the solid electrolyte 30 and the first anode active material layer 23.

The second anode active material layer 24 induces precipitation of lithium metal on the current collector layer, thereby preventing direct contact between the solid electrolyte and the lithium metal. When lithium is used or metal that easily causes formation of a lithium alloy is charged, lithium is mainly precipitated between the first anode active material layer and the current collector. Therefore, deterioration of the first anode active material layer and the intermediate layer due to short circuit of the battery and repeated charge and discharge can be effectively prevented.

The anode-solid electrolyte proton assembly according to the embodiment may be applied to an anode of a multi-layered structure as described above, thereby preparing an all-solid secondary battery that may allow stable operation.

In formula 1, M1 may be aluminum (Al), zinc (Zn), tin (Sn), silicon (Si), germanium (Ge), copper (Cu), indium (In), gallium (Ga), titanium (Ti), zirconium (Zr), niobium (Nb), antimony (Sb), bismuth (Bi), gold (Au), platinum (Pt), palladium (Pd), nickel (Ni), iron (Fe), cobalt (Co), chromium (Cr), magnesium (Mg), cerium (Ce), cesium (Cs), silver (Ag), sodium (Na), potassium (K), calcium (Ca), yttrium (Y), tantalum (Ta), hafnium (Hf), barium (Ba), vanadium (V), strontium (Sr), tellurium (Te), lanthanum (La), or a combination thereof.

In formula 2, M2 may be aluminum (Al), zinc (Zn), tin (Sn), silicon (Si), germanium (Ge), copper (Cu), indium (In), gallium (Ga), titanium (Ti), zirconium (Zr), niobium (Nb), antimony (Sb), bismuth (Bi), gold (Au), platinum (Pt), palladium (Pd), nickel (Ni), iron (Fe), cobalt (Co), chromium (Cr), magnesium (Mg), cesium (Cs), cerium (Ce), silver (Ag), sodium (Na), potassium (K), calcium (Ca), yttrium (Y), tantalum (Ta), hafnium (Hf), barium (Ba), vanadium (V), strontium (Sr), tellurium (Te), lanthanum (La), or a combination thereof.

The compound of formula 1 may be, for example, li _x Al (0 therein)<x<5)，Li _x Sn (0 therein<x<5)，Li _X Si _y (wherein x is 1.ltoreq.3 and y is 1.ltoreq.3), li _x Ge _y (wherein x is 1.ltoreq.3 and y is 1.ltoreq.3), li _x Cu _y (wherein x is 1.ltoreq.3 and y is 1.ltoreq.3), li _x Zn (0 therein)<x<5)，Li _x Sb (0 therein)<x<4)，Li _x Si (0 therein)<x<5)，Li _x Au (0 therein<x<5)，Li _x Ag (0 therein)<x<10)，Li _x In (0 therein<x<5)，Li _x Bi (0 therein)<x<5)，Li _x Ga (0 therein)<x<5)，Li _x Te (0 therein)<x<5)，Li _x Ge (0 therein)<x<5)，Li _x Mg (0 therein<x<7) Or a combination thereof.

The compound of formula 1 may be, for example: li (Li) ₃ Al，Li ₂ Zn，Li ₄ Sn，Li _X Si _y (wherein x is 1.ltoreq.3 and y is 1.ltoreq.3), li _x Ge _y (wherein x is 1.ltoreq.3 and y is 1.ltoreq.3), li _x Cu _y (x is more than or equal to 1 and less than or equal to 3, y is more than or equal to 1 and less than or equal to 3), or a combination thereof.

Li _x Sn (0 therein<x<5) Can be, for example, li ₄ Sn or Li _4.4 Sn。

Li _x Si (0 therein)<x<5) Can be, for example, li ₄ Si or Li _4.4 Si。

Li _x Ge (0 therein)<x<5) Can be, for example, li ₁₅ Ge ₄ (Li _3.75 Ge) or Li ₉ Ge ₄ (Li _2.25 Ge)。

Li _x Al (0 therein)<x<4) Can be, for example, li ₃ Al。

The compound of formula 2 may be, for example, li ₃ N，Al _a N _b (wherein a is more than or equal to 1 and less than or equal to 3 and b is more than or equal to 1 and less than or equal to 4), zn _a N _b (wherein a is 1-3 and b is 1-4), sn _a N _b (wherein a is 1-3 and b is 1-4), si _a N _b (wherein a is more than or equal to 1 and less than or equal to 3 and b is more than or equal to 1 and less than or equal to 4), ge _a N _b (wherein a is more than or equal to 1 and less than or equal to 3 and b is more than or equal to 1 and less than or equal to 4), cu _a N _b (wherein a is 1-3 and b is 1-4), in _a N _b (wherein a is 1-3 and b is 1-4) and Ga _a N _b (wherein a is 1-3 and b is 1-4), ti _a N _b (wherein a is more than or equal to 1 and less than or equal to 3 and b is more than or equal to 1 and less than or equal to 4), zr _a N _b (wherein a is more than or equal to 1 and less than or equal to 3 and b is more than or equal to 1 and less than or equal to 4), nb _a N _b (wherein 1.ltoreq.a.ltoreq.3 and 1.ltoreq.b.ltoreq.4), or combinations thereof.

The compound of formula 2 may be, for example, li ₃ N，AlN，Zn ₃ N ₂ ，Sn _a N _b ，Si _a N _b ，Ge _a N _b ，Cu ₃ N, or a combination thereof, wherein 1.ltoreq.a.ltoreq.3 and 1.ltoreq.b.ltoreq.4.

Sn _a N _b Can be, for example, sn ₃ N ₄ 。Si _a N _b Can be, for example, si ₃ N ₄ 。Ge _a N _b May be, for example, ge ₃ N ₄ 。

The compound of formula 2 may comprise Li ₃ N. Li compared with lithium oxide and lithium fluoride ₃ N may have high ionic conductivity.

The first anode active material layer may have a thickness in a range of about 1 nanometer (nm) to about 100 micrometers (μm), about 10nm to about 100 μm, about 20nm to about 50 μm, about 50nm to about 40 μm, about 100nm to about 30 μm, or about 300nm to about 20 μm. When the thickness of the first anode active material layer is within any of these ranges, the all-solid secondary battery may have excellent cycle characteristics. When the thickness of the first anode active material layer is within any of these ranges, deterioration of the anode can be prevented during repeated charge and discharge, and lithium movement can be increased, thereby manufacturing an all-solid secondary battery having improved high-rate characteristics and life characteristics.

According to an embodiment, when the first anode active material layer is analyzed by X-ray photoelectron spectroscopy (XPS), four to five peaks may be observed in a region of about 393 electron volts to about 405 electron volts in the graph of intensity versus binding energy. The four to five peaks may be with respect to, for example, li ₃ N, N is a metal alloy.

The thickness of the intermediate layer may be in the range of about 5nm to about 100nm, about 5nm to about 50nm, about 10nm to about 30nm, or about 10nm to about 20 nm. When the thickness of the intermediate layer is within any of these ranges, conduction of electrons to the solid electrolyte can be blocked, so that occurrence of short circuit due to precipitation of lithium into the solid electrolyte can be prevented.

In this specification, when the thickness of each layer is not uniform, the average thickness of each layer can be defined by calculating an average value. The average thickness can be calculated by analyzing the thickness of each layer by scanning electron microscopy.

3

M2 _a O _b

Wherein in formula 2, the second metal (M2) may be lithium, an element capable of forming a compound or alloy with lithium and nitrogen, or a combination thereof, and

In formula 3, M2 may be aluminum (Al), zinc (Zn), tin (Sn), silicon (Si), germanium (Ge), copper (Cu), indium (In), gallium (Ga), titanium (Ti), zirconium (Zr), niobium (Nb), antimony (Sb), bismuth (Bi), gold (Au), platinum (Pt), palladium (Pd), nickel (Ni), iron (Fe), cobalt (Co), chromium (Cr), magnesium (Mg), cesium (Ce), silver (Ag), sodium (Na), potassium (K), calcium (Ca), yttrium (Y), tantalum (Ta), hafnium (Hf), barium (Ba), vanadium (V), strontium (Sr), tellurium (Te), lanthanum (La), or a combination thereof.

In formula 3, 1.ltoreq.a.ltoreq.18, 1.ltoreq.a.ltoreq.16, 1.ltoreq.a.ltoreq.14, 1.ltoreq.a.ltoreq.15, 1.ltoreq.a.ltoreq.12, 1.ltoreq.a.ltoreq.10, 1.ltoreq.a.ltoreq.8, 1.ltoreq.a.ltoreq.6, 1.ltoreq.a.ltoreq.5 or 1.ltoreq.a.ltoreq.3, and 1.ltoreq.b.ltoreq.8, 1.ltoreq.b.ltoreq.5 or 1.ltoreq.b.ltoreq.4.

The compound of formula 3 may be SnO ₂ 、CuO、SiO ₂ 、GeO、Al ₂ O ₃ ZnO, or combinations thereof.

The first anode active material layer in the anode-solid electrolyte proton assembly according to the embodiment may be: li (Li) _x Sn _y And Li (lithium) _a N _b Is a complex of (a) and (b); li (Li) _x Sn _y 、Sn _a N _b And SnO ₂ Is a complex of (a) and (b); li, li _x Sn _y And Li (lithium) _a N _b Is a complex of (a) and (b); li, li _x Sn _y 、Sn _a N _b And SnO ₂ Is a complex of (a) and (b); li, cuN _x And LiN _y Is a complex of (a) and (b); li, cu, liN _y Or Li (lithium) _x Cu _y And Li _a N _b Is a complex of (a) and (b); li (Li) _x Sn _y And Li (lithium) _a N _b Is a mixture of (a) and (b); li (Li) _x Sn _y 、Sn _a N _b And SnO ₂ Is a mixture of (a) and (b); li, li _x Sn _y And Li (lithium) _a N _b Is a mixture of (a) and (b); li, li _x Sn _y 、Sn _a N _b And SnO ₂ Is a mixture of (a) and (b); li, cuN _x And LiN _y Is a mixture of (a) and (b); or Li, cu, liN _y Or Li (lithium) _x Cu _y And Li _a N _b Is a mixture of (a) and (b).

In the above formulae, the respective ranges of x, y, a and b may be the same as defined in formulae 1 and 2.

Here, the term "structure" refers to a mixture, a complex, or a combination thereof. For example, the structure is a mixture.

The third metal material of the intermediate layer may be a mixture of a compound of formula 4 and a compound of formula 5, a complex of a compound of formula 4 and a compound of formula 5, or a combination thereof:

4. The method is to

Li _a -M3 _b -O _c

Wherein in formula 4, the third metal (M3) may be Al, zn, sn, si, ge, cu, in, ga, ti, zr, nb, sb, bi, au, pt, pd, ni, fe, co, cr, mg, ce, ag, na, K, ca, Y, ta, hf, ba, V, sr, te, la, or a combination thereof, and

A is more than or equal to 1 and less than or equal to 20, b is more than or equal to 1 and less than or equal to 10, c is more than or equal to 1 and less than or equal to 10,

5. The method is to

M3 _c O _d

Wherein in formula 5, the third metal (M3) may be Al, zn, sn, si, ge, cu, in, ga, ti, zr, nb, sb, bi, au, pt, pd, ni, fe, co, cr, mg, ce, ag, na, K, ca, Y, bi, ta, hf, au, ba, V, sr, te, la, or a combination thereof, and

c is more than or equal to 1 and less than or equal to 20, and d is more than or equal to 1 and less than or equal to 30.

For example, in formula 4, 1.ltoreq.a.ltoreq.10, 1.ltoreq.b.ltoreq.8, and 1.ltoreq.c.ltoreq.8, or 1.ltoreq.a.ltoreq.9, 1.ltoreq.b.ltoreq.3, and 1.ltoreq.c.ltoreq.7, and in formula 5, 1.ltoreq.c.ltoreq.10, and 1.ltoreq.d.ltoreq.28, or 1.ltoreq.c.ltoreq.5, and 1.ltoreq.d.ltoreq.25.

The third metal material may be, for example, li _a -Sn _b -O _c (wherein 0<a≤9，0<b is less than or equal to 3 and 0<c.ltoreq.7) and Sn _c O _d (wherein 0<c.ltoreq.3 and 0<d.ltoreq.4), li _a -Cu _b -O _c (wherein 0<a≤9，0<b is less than or equal to 3 and 0<c.ltoreq.7) and Cu _c O _d (wherein 0<c is less than or equal to 5 and 0<d.ltoreq.24), li _a -Sn _b -O _c (wherein 0<a≤9，0<b is less than or equal to 3 and 0<c.ltoreq.7) and Sn _c O _d (wherein 0<c.ltoreq.3 and 0<d.ltoreq.4), li _a -Cu _b -O _c (wherein 0<a≤9，0<b is less than or equal to 3 and 0<c.ltoreq.7) and Cu _c O _d (wherein 0<c is less than or equal to 5 and 0<d.ltoreq.24), or a combination thereof.

The volume of the first anode active material layer after charging the all-solid secondary battery may be 200% (%) or less of the volume of the first anode active material layer after discharging, for example, about 100% to about 200%, about 120% to about 180%, or about 140% to about 160% of the volume of the first anode active material layer after discharging. An all-solid secondary battery having the first anode active material layer having such a volume change rate may have excellent cycle characteristics.

The second anode active material layer 24 may be between the anode current collector and the first anode active material layer. The second anode active material layer 24 may be further added at the time of assembling the battery. In an embodiment, the second anode active material layer 24 may be a precipitation layer formed after the battery is charged.

In an embodiment, the anode current collector, the intermediate layer, the first anode active material layer, the second anode active material layer, and the region between the anode current collector, the intermediate layer, the first anode active material layer, and the second anode active material layer may be a lithium-free (Li) region that may not include lithium (Li) in an initial state or a post-discharge state of the all-solid secondary battery, as needed.

The second anode active material layer may be formed as a precipitation layer and/or a deposition layer during charging of an all-solid secondary battery, disposing the anode current collector on the first anode active material layer, or both during charging and disposing the anode current collector on the first anode active material layer. The second anode active material layer may be a lithium metal layer or a lithium metal alloy layer.

The second anode active material layer may include a fourth metal (i.e., M4). The fourth metal may be a metal that may react with lithium to form an alloy or compound, or a metal that may not react with lithium. The fourth metal may be a group 2 to 15 element. "group" refers to a group of the periodic Table of elements according to the International Union of pure and applied chemistry ("IUPAC") group 1-18 taxonomy.

The fourth metal may include silver (Ag), tin (Sn), indium (In), silicon (Si), gallium (Ga), aluminum (Al), titanium (Ti), zirconium (Zr), niobium (Nb), germanium (Ge), antimony (Sb), bismuth (Bi), zinc (Zn), gold (Au), platinum (Pt), palladium (Pd), nickel (Ni), iron (Fe), cobalt (Co), chromium (Cr), magnesium (Mg), cesium (Cs), cerium (Ce), lanthanum (La), tungsten (W), tellurium (Te), or a combination thereof.

The lithium alloy may include silver (Ag), tin (Sn), indium (In), silicon (Si), gallium (Ga), aluminum (Al), titanium (Ti), zirconium (Zr), niobium (Nb), germanium (Ge), antimony (Sb), bismuth (Bi), zinc (Zn), gold (Au), platinum (Pt), palladium (Pd), nickel (Ni), iron (Fe), cobalt (Co), chromium (Cr), magnesium (Mg), cesium (Cs), cerium (Ce), lanthanum (La), tungsten (W), tellurium (Te), or a combination thereof.

In an embodiment, the second anode active material layer 24 may form a Li-M4 alloy due to a reaction between lithium precipitated through a reversible reaction of the all-solid secondary battery during the charging and discharging process and the fourth metal (M4). Accordingly, the second anode active material layer 24 may contain a Li-M4 alloy.

In particular, the second anode active material layer 24 may be a single metal layer of Ag or Sn or a lithium metal monolayer before charging (i.e., before precipitation by charging) or from an initial state.

When the second anode active material layer includes a lithium alloy such as ag—li, a silver layer may be formed when the battery is assembled, and lithium may be precipitated in the silver layer during charging of the all-solid secondary battery, disposing the anode current collector on the first anode active material layer, or both of the charging and disposing the anode current collector on the first anode active material layer, thereby forming a lithium alloy layer such as ag—li layer. Disposing the anode current collector on the first anode active material layer may be, for example, bonding the anode current collector to the first anode active material layer.

When the second anode active material layer is formed as a single layer of the fourth metal (e.g., a silver layer) at the time of assembling the battery, the thickness of the second anode active material layer may be in the range of, for example, about 20nm to about 50 μm, about 20nm to about 40 μm, about 20nm to about 1 μm, about 100nm to about 1 μm, or about 300nm to about 600 nm.

When the Li metal layer is used from the start of the assembly of the battery, the thickness of the second anode active material layer may be, for example, about 20 μm to about 40 μm.

The first anode active material layer may reduce volume expansion during charge and discharge, and may improve uniformity of lithium distribution.

The interfacial resistance between the intermediate layer 22 and the solid electrolyte 30 may be less than or equal to a certain level.For example, the interfacial resistance between the intermediate layer 22 and the solid electrolyte 30 may be less than or equal to 500 ohm-square centimeters (ohm-cm) ² ). For example, the interfacial resistance between the intermediate layer 22 and the solid electrolyte 30 may be less than or equal to 200ohm cm ² 。

Fig. 14 is a schematic view illustrating an all-solid secondary battery 1 according to an embodiment.

As shown in fig. 14, the all-solid secondary battery 1 may be a secondary battery including a solid electrolyte as an electrolyte.

The all-solid secondary battery 1 may include a positive electrode 10, a solid electrolyte 30, and a negative electrode 20.

Positive electrode

The positive electrode 10 may include a positive electrode current collector 11 and a positive electrode active material layer 12.

Examples of the positive electrode current collector 11 include a plate or foil including indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof.

The positive electrode active material layer 12 may include, for example, a positive electrode active material.

The positive electrode active material may be any suitable positive electrode active material capable of reversibly intercalating and deintercalating lithium ions. For example, the positive electrode active material may be a lithium transition metal oxide, such as Lithium Cobalt Oxide (LCO), lithium nickel oxide, lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NCM), lithium manganate, or lithium iron phosphate, nickel sulfide, copper sulfide, lithium sulfide, iron oxide, or vanadium oxide. But the embodiment is not limited thereto. Any suitable positive electrode active material available in the art may be used. The positive electrode active material may be used alone or in combination of at least two thereof.

The positive electrode active material may be, for example, a compound represented by one of the following formulas: li (Li) _a A _1-b B’ _b D ₂ Wherein a is more than or equal to 0.9 and less than or equal to 1, and b is more than or equal to 0 and less than or equal to 0.5; li (Li) _a E _1-b B’ _b O _2-c D _c Wherein a is more than or equal to 0.9 and less than or equal to 1, b is more than or equal to 0 and less than or equal to 0.5, and c is more than or equal to 0 and less than or equal to 0.05; liE _2-b B’ _b O _4- _c D _c Wherein b is more than or equal to 0 and less than or equal to 0.5, and c is more than or equal to 0 and less than or equal to 0.05; li (Li) _a Ni _1-b-c Co _b B’ _c D _α Wherein a is more than or equal to 0.9 and less than or equal to 1, b is more than or equal to 0 and less than or equal to 0.5, c is more than or equal to 0 and less than or equal to 0.05, and 0<α≥2；Li _a Ni _1-b-c Co _b B’ _c O _2-α F’ _α Wherein a is more than or equal to 0.9 and less than or equal to 1, b is more than or equal to 0 and less than or equal to 0.5, c is more than or equal to 0 and less than or equal to 0.05, and 0<α<2；Li _a Ni _1-b-c Co _b B’ _c O _2-α F’ ₂ Wherein a is more than or equal to 0.9 and less than or equal to 1, b is more than or equal to 0 and less than or equal to 0.5, c is more than or equal to 0 and less than or equal to 0.05, and 0<α<2；Li _a Ni _1-b-c Mn _b B’ _c D _α Wherein a is more than or equal to 0.9 and less than or equal to 1, b is more than or equal to 0 and less than or equal to 0.5, c is more than or equal to 0 and less than or equal to 0.05, and 0<α≤2；Li _a Ni _1-b-c Mn _b B’ _c O _2-α F’ _α Wherein a is more than or equal to 0.9 and less than or equal to 1, b is more than or equal to 0 and less than or equal to 0.5, c is more than or equal to 0 and less than or equal to 0.05, and 0<α<2；Li _a Ni _1-b-c Mn _b B’ _c O _2-α F’ ₂ Wherein a is more than or equal to 0.9 and less than or equal to 1, b is more than or equal to 0 and less than or equal to 0.5, c is more than or equal to 0 and less than or equal to 0.05, and 0<α<2；Li _a Ni _b E _c G _d O ₂ Wherein a is more than or equal to 0.9 and less than or equal to 1, b is more than or equal to 0 and less than or equal to 0.9, c is more than or equal to 0 and less than or equal to 0.5, and d is more than or equal to 0.001 and less than or equal to 0.1; li (Li) _a Ni _b Co _c Mn _d G _e O ₂ Wherein a is more than or equal to 0.9 and less than or equal to 1, b is more than or equal to 0 and less than or equal to 0.9, c is more than or equal to 0 and less than or equal to 0.5, d is more than or equal to 0 and less than or equal to 0.5, and e is more than or equal to 0.001 and less than or equal to 0.1; li (Li) _a NiG _b O ₂ Wherein a is more than or equal to 0.9 and less than or equal to 1, and b is more than or equal to 0.001 and less than or equal to 0.1; li (Li) _a CoG _b O ₂ Wherein a is more than or equal to 0.9 and less than or equal to 1, and b is more than or equal to 0.001 and less than or equal to 0.1; li (Li) _a MnG _b O ₂ Wherein a is more than or equal to 0.9 and less than or equal to 1, and b is more than or equal to 0.001 and less than or equal to 0.1; li (Li) _a Mn ₂ G _b O ₄ Wherein a is more than or equal to 0.9 and less than or equal to 1, and b is more than or equal to 0.001 and less than or equal to 0.1; QO (quality of service) ₂ ；QS ₂ ；LiQS ₂ ；V ₂ O ₅ ；LiV ₂ O ₅ ；LiI’O ₂ ；LiNiVO ₄ ；Li _(3-f) J ₂ (PO ₄ ) ₃ Wherein f is more than or equal to 0 and less than or equal to 2; li (Li) _(3-f) Fe ₂ (PO ₄ ) ₃ Wherein f is more than or equal to 0 and less than or equal to 2; liFePO ₄ The method comprises the steps of carrying out a first treatment on the surface of the Or a combination thereof. In these compounds, A may be nickel (Ni), cobalt (Co),Manganese (Mn), or a combination thereof; b' may be aluminum (Al), ni, co, mn, chromium (Cr), iron (Fe), magnesium (Mg), strontium (Sr), vanadium (V), rare earth elements, or combinations thereof; d may be oxygen (O), fluorine (F), sulfur (S), phosphorus (P), or a combination thereof; e may be Co, mn, or a combination thereof; f' may be F, S, P, or a combination thereof; g may be Al, cr, mn, fe, mg, lanthanum (La), cerium (Ce), sr, V, or a combination thereof; q may be titanium (Ti), molybdenum (Mo), mn, or a combination thereof; i' may be Cr, V, fe, scandium (Sc), yttrium (Y), or a combination thereof; and J may be V, cr, mn, co, ni, copper (Cu), or a combination thereof. It is also possible to use a compound to which a coating layer formed on one of these compounds is added, and it is also possible to use a mixture of these compounds and a compound to which a coating layer is added. In embodiments, the coating layer added on the surface of these compounds may include at least one compound of a coating element as follows: an oxide, hydroxide, oxyhydroxide, oxycarbonate, hydroxycarbonate, or a combination thereof of the capping element. In embodiments, these compounds comprising the coating layer may be amorphous or crystalline. In an embodiment, the coating element included in the coating layer may be magnesium (Mg), aluminum (Al), cobalt (Co), potassium (K), sodium (Na), calcium (Ca), silicon (Si), titanium (Ti), vanadium (V), tin (Sn), germanium (Ge), gallium (Ga), boron (B), arsenic (As), zirconium (Zr), or a mixture thereof. The method of forming the coating layer may be selected within a range that does not affect the physical properties of the positive electrode active material. The coating method may be, for example, a spraying method or a dipping method. A detailed description of the coating method is omitted herein because the method is easily understood by one of ordinary skill in the art.

The positive electrode active material may include, for example, a lithium salt of a transition metal oxide having a layered rock-salt type structure among the lithium transition metal oxides. The term "layered rock salt type structure" as used herein refers to the structure: wherein the atomic layers of oxygen and metal are in a cubic rock salt structure<111>Alternating in direction and regularly arranged, and the respective atomic layers thus form a two-dimensional plane. The term "cubic rock salt type structure" as used herein refers to a NaCl type structure as one of crystal structures, in which the structure is formed of anions and cations, respectivelyIs offset by only half of the ridges of each unit cell. An example of a lithium transition metal oxide having a layered rock salt type structure may be a material composed of LiNi _x Co _y Al _z O ₂ (NCA) or LiNi _x Co _y Mn _z O ₂ (NCM) ternary lithium transition Metal oxide, wherein 0<x<1，0<y<1，0<z<1, and x+y+z=1. When the positive electrode active material includes a ternary lithium transition metal oxide having a layered rock-salt type structure, the all-solid secondary battery 1 may have further improved energy density and thermal stability.

The positive electrode active material may be covered with the cover layer as described above. The coating layer may be any suitable coating layer known as a coating layer of a positive electrode active material in the all-solid secondary battery 1. Examples of the covering layer include Li ₂ O-ZrO ₂ 。

For example, when the positive electrode active material includes nickel (Ni) as a ternary lithium transition metal oxide such as NCA or NCM, the capacity density of the all-solid secondary battery 1 may be increased, thereby allowing for a reduction in metal elution of the positive electrode active material upon charging. Accordingly, the all-solid secondary battery 1 can have improved cycle characteristics.

The positive electrode active material may be, for example, in a particle shape, such as a spherical shape or an ellipsoidal shape. The particle diameter of the positive electrode active material is not particularly limited. This diameter may be in a range suitable for the positive electrode active material of the all-solid secondary battery 1 in the related art. The content of the positive electrode active material of the positive electrode 10 is not particularly limited. This content may be within a range suitable for the positive electrode 10 of the all-solid secondary battery 1 in the related art.

The positive electrode 10 may further include additives such as a conductive agent, a binder, a filler, a dispersant, and an ion-conducting agent, in addition to the positive electrode active material. Examples of the conductive agent include graphite, carbon black, acetylene black, ketjen black, carbon fiber, and metal powder. Examples of the binder may include, for example, styrene Butadiene Rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, and polyethylene. Further, the filler, dispersant, or ion-conducting agent that may be included in the positive electrode 10 may be any suitable material for an electrode in a solid secondary battery.

The positive electrode 10 may further include a solid electrolyte. The solid electrolyte included in the positive electrode 10 may be the same as (similar to) or different from the solid electrolyte included in the solid electrolyte 30. The solid electrolyte will be described in detail with reference to the solid electrolyte 30.

The solid electrolyte included in the positive electrode 10 may be, for example, a sulfide-based solid electrolyte (i.e., sulfide solid electrolyte). The sulfide-based solid electrolyte may be a sulfide-based solid electrolyte used in the solid electrolyte 30.

In an embodiment, the positive electrode 10 may be immersed in a liquid electrolyte, for example. The liquid electrolyte may include a lithium salt, an ionic liquid, a polymeric ionic liquid, or a combination thereof. The liquid electrolyte may be non-volatile. The term "ionic liquid" refers to a salt that is liquid at room temperature or a room temperature molten salt that has a melting point of room temperature or less and contains ions. The ionic liquid may be a compound comprising at least one of the following: a) The following cations: an ammonium cation, a pyrrolidinium cation, a pyridinium cation, a pyrimidinium cation, an imidazolium cation, a piperidinium cation, a pyrazolium cation, an oxazolium cation, a pyridazinium cation, a phosphonium cation, a sulfonium cation, a triazolium cation, or a combination thereof, and b) an anion of: BF (BF) ₄ ^- 、PF ₆ ^- 、AsF ₆ ^- 、SbF ₆ ^- 、AlCl ₄ ^- 、HSO ₄ ^- 、ClO ₄ ^- 、CH ₃ SO ₃ ^- 、CF ₃ CO ₂ ^- 、Cl ^- 、Br ^- 、I ^- 、SO ₄ ^2- 、CF ₃ SO ₃ ^- 、(FSO ₂ ) ₂ N ^- 、(C ₂ F ₅ SO ₂ ) ₂ N ^- 、(C ₂ F ₅ SO ₂ )(CF ₃ SO ₂ )N ^- 、(CF ₃ SO ₂ ) ₂ N ^- Or a combination thereof. For example, the ionic liquid mayIs bis (trifluoromethanesulfonyl) imide N-methyl-N-propylpyrrolidinium, bis (trifluoromethanesulfonyl) imide N-butyl-N-methylpyrrolidinium, bis (trifluoromethanesulfonyl) imide 1-butyl-3-methylimidazolium, bis (trifluoromethanesulfonyl) imide 1-ethyl-3-methylimidazolium, or a combination thereof. The polymeric ionic liquid may comprise repeating units comprising: a) The following cations: ammonium cations, pyrrolidinium cations, pyridinium cations, pyrimidinium cations, imidazolium cations, piperidinium cations, pyrazolium cations, oxazolium cations, pyridazinium cations, phosphonium cations, sulfonium cations, triazolium cations, or mixtures thereof; and b) the following anions: BF (BF) ₄ ^- 、PF ₆ ^- 、AsF ₆ ^- 、SbF ₆ ^- 、AlCl ₄ ^- 、HSO ₄ ^- 、ClO ₄ ^- 、CH ₃ SO ₃ ^- 、CF ₃ CO ₂ ^- 、(CF ₃ SO ₂ ) ₂ N ^- 、(FSO ₂ ) ₂ N ^- 、Cl ^- 、Br ^- 、I ^- 、SO ₄ ^2- 、CF ₃ SO ₃ ^- 、(C ₂ F ₅ SO ₂ ) ₂ N ^- 、(C ₂ F ₅ SO ₂ )(CF ₃ SO ₂ )N ^- 、NO ₃ ^- 、Al ₂ Cl ₇ ^- 、(CF ₃ SO ₂ ) ₃ C ^- 、(CF ₃ ) ₂ PF ₄ ^- 、(CF ₃ ) ₃ PF ₃ ^- 、(CF ₃ )4PF ₂ ^- 、(CF ₃ ) ₅ PF ^- 、(CF ₃ ) ₆ P ^- 、SF ₅ CF ₂ SO ₃ ^- 、SF ₅ CHFCF ₂ SO ₃ ^- 、CF ₃ CF ₂ (CF ₃ ) ₂ CO ^- 、(CF ₃ SO ₂ ) ₂ CH ^- 、(SF ₅ ) ₃ C ^- 、(O(CF ₃ ) ₂ C ₂ (CF ₃ ) ₂ O) ₂ PO ^- Or a combination thereof. The lithium salt may be any suitable lithium salt available in the art. For example, the lithium salt may be LiPF ₆ 、LiBF ₄ 、LiSbF ₆ 、LiAsF ₆ 、LiClO ₄ 、LiCF ₃ SO ₃ 、Li(CF ₃ SO ₂ ) ₂ N、Li(FSO ₂ ) ₂ N、LiC ₄ F ₉ SO ₃ 、LiAlO ₂ 、LiAlCl ₄ 、LiN(C _x F _2x+1 SO ₂ )(C _y F _2y+1 SO ₂ ) (wherein x and y are natural numbers), liCl, liI, or combinations thereof. The liquid electrolyte may include a lithium salt at a concentration in the range of about 0.1 molar (M) to about 5M. The content of the liquid electrolyte impregnated in the positive electrode 10 may be in the range of about 0 to about 100 parts by weight, about 0 to about 50 parts by weight, about 0 to about 30 parts by weight, about 0 to about 20 parts by weight, about 0 to about 10 parts by weight, or about 0 to about 5 parts by weight, based on 100 parts by weight of the positive electrode active material layer 12 excluding the liquid electrolyte.

Solid electrolyte

The solid electrolyte layer 30 may be between the positive electrode 10 and the negative electrode 20.

The solid electrolyte may be an oxide-based solid electrolyte, a sulfide-based solid electrolyte, or a combination thereof. The solid electrolyte may be, for example, an oxide-based solid electrolyte. The oxide-based solid electrolyte may be Li _1+x+y Al _x Ti _2-x Si _y P _3-y O ₁₂ (wherein 0<x<2 and 0.ltoreq.y<3)，Li ₃ PO ₄ ，Li _x Ti _y (PO ₄ ) ₃ (wherein 0<x<2 and 0<y<3)，Li _x Al _y Ti _z (PO ₄ ) ₃ (wherein 0<x<2、0<y<1. And 0 is<z<3)，Li _1+x+y (Al _p Ga _1-p ) _x (Ti _q Ge _1-q ) _2-x Si _y P _3-y O ₁₂ (wherein x is more than or equal to 0 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 1, p is more than or equal to 0 and less than or equal to 1, and q is more than or equal to 0 and less than or equal to 1), li _x La _y TiO ₃ (wherein 0<x<2 and 0<y<3)，Li ₂ O，LiOH，Li ₂ CO ₃ ，LiAlO ₂ ，Li ₂ O-Al ₂ O ₃ -SiO ₂ -P ₂ O ₅ -TiO ₂ -GeO ₂ ，Li _3+x La ₃ M ₂ O ₁₂ (wherein m=te, nb, or Zr, and x may be an integer from 1 to 10), or a combination thereof. The solid electrolyte may be prepared by sintering.

The oxide-based solid electrolyte may be, for example, a garnet-type solid electrolyte.

A non-limiting example of the garnet-type solid electrolyte may be an oxide represented by formula 6:

6. The method is to

(Li _x M1 _y )(M2) _3-δ (M3) _2-ω O _12-z X _z

Wherein in formula 6, x is 3-8, y is 0-2, delta is 0.2-omega-0.2, and z is 0-2,

m1 may be a monovalent cation, a divalent cation, a trivalent cation, or a combination thereof,

m2 may be a monovalent cation, a divalent cation, a trivalent cation, or a combination thereof,

m3 may be a monovalent cation, divalent cation, trivalent cation, tetravalent cation, pentavalent cation, hexavalent cation, or combinations thereof, and

X may be a monovalent anion, a divalent anion, a trivalent anion, or a combination thereof.

In formula 6, for example, 6.ltoreq.x.ltoreq.8.

In formula 6, examples of the monovalent cations may include Na, K, rb, cs, H and Fr, and examples of the divalent cations may include Mg, ca, ba, and Sr. Examples of the trivalent cations may include In, sc, cr, au, B, al and Ga, and examples of the tetravalent cations may include Sn, ti, mn, ir, ru, pd, mo, hf, ge, V and Si. Examples of the pentavalent cations may include Nb, ta, sb, V and P.

M1 may Be, for example, hydrogen (H), iron (Fe), gallium (Ga), aluminum (Al), boron (B), beryllium (Be), or combinations thereof. M2 may be lanthanum (La), barium (Ba), calcium (Ca), strontium (Sr), yttrium (Y), bismuth (Bi), praseodymium (Pr), neodymium (Nd), actinium (Ac), samarium (Sm), gadolinium (Gd), or a combination thereof, and M3 may be zirconium (Zr), hafnium (Hf), tin (Sn), niobium (Nb), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), molybdenum (Mo), tungsten (W), tantalum (Ta), magnesium (Mg), technetium (Tc), ruthenium (Ru), palladium (Pd), iridium (Ir), scandium (Sc), cadmium (Cd), indium (In), antimony (Sb), tellurium (Te), thallium (Tl), platinum (Pt), silicon (Si), aluminum (Al), or a combination thereof.

In formula 6, the monovalent anion represented by X may be halogen, pseudohalogen, or a combination thereof, and the divalent anion represented by X may be S ^2- Or Se ^2- And the trivalent anion represented by X may be, for example, N ^3- 。

In formula 6, 3.5.ltoreq.x.ltoreq.8, 4.ltoreq.x.ltoreq.8, 4.5.ltoreq.x.ltoreq.8, 5.ltoreq.x.ltoreq.8, 6.6.ltoreq.x.ltoreq.8, 6.7.ltoreq.x.ltoreq.7.5, or 6.8.ltoreq.x.ltoreq.7.1.

A non-limiting example of the garnet-type solid electrolyte may be an oxide represented by formula 7:

7. The method of the invention

(Li _x M1 _y )(La _a1 M2 _a2 ) _3-δ (Zr _b1 M3 _b2 ) _2-ω O _12-z X _z

Wherein in formula 7, M1 may Be hydrogen (H), iron (Fe), gallium (Ga), aluminum (Al), boron (B), beryllium (Be), or a combination thereof,

M2 may be barium (Ba), calcium (Ca), strontium (Sr), yttrium (Y), bismuth (Bi), praseodymium (Pr), neodymium (Nd), actinium (Ac), samarium (Sm), gadolinium (Gd), or a combination thereof,

M3 may be hafnium (Hf), tin (Sn), niobium (Nb), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), cobalt (Co), nickel (Ni), copper (Cu), molybdenum (Mo), tungsten (W), tantalum (Ta), magnesium (Mg), technetium (Tc), ruthenium (Ru), palladium (Pd), iridium (Ir), scandium (Sc), cadmium (Cd), indium (In), antimony (Sb), tellurium (Te), thallium (Tl), platinum (Pt), silicon (Si), aluminum (Al), or combinations thereof,

x is more than or equal to 3 and less than or equal to 8, y is more than or equal to 0 and less than or equal to 2, -delta is more than or equal to 0.2 and less than or equal to 0.2, omega is more than or equal to 0.2 and less than or equal to 0 and less than or equal to 2,

a1+a2=1, 0< a1.ltoreq.1, and 0.ltoreq.a2 <1,

b1+b2=1, 0< b1.ltoreq.1, and 0.ltoreq.b2 <1, and

In formula 7, the monovalent anion represented by X may be halogen, pseudohalogen, or a combination thereof, and the divalent anion represented by X may be S ^2- Or Se ^2- And the trivalent anion represented by X may be, for example, N ^3- 。

In formula 7, 4.ltoreq.x.ltoreq.8, 4.5.ltoreq.x.ltoreq.8, 5.5.ltoreq.x.ltoreq.8, 6.ltoreq.x.ltoreq.8, 6.6.ltoreq.x.ltoreq.8, 6.7.ltoreq.x.ltoreq.7.5, or 6.8.ltoreq.x.ltoreq.7.1.

The term "pseudohalogen" as used herein refers to a molecule consisting of at least two electronegative atoms that resemble a halogen in the free state and produce anions similar to halide ions. Examples of pseudohalogens include cyanide (cyanate), cyanate (cyanate), thiocyanate (thiocyanate), azide (azide), or combinations thereof.

Examples of halogens include iodine (I), chlorine (Cl), bromine (Br), fluorine (F), or combinations thereof. Examples of pseudohalogens include cyanide (cyanate), cyanate (cyanate), thiocyanate (thiocyanate), azide (azide), or combinations thereof.

The trivalent anion may be, for example, N ^3- 。

In an embodiment, the garnet-type solid electrolyte may be an oxide represented by formula 8:

8. The method is used for preparing the product

Li _3+x La ₃ Zr _2-a M _a O ₁₂

Wherein in formula 8, M may be Al, ga, in, si, ge, sn, sb, bi, sc, Y, ti, hf, V, nb, ta, W, or a combination thereof, wherein x may be an integer from 1 to 10, and 0.ltoreq.a <2.

The garnet-type solid electrolyte may be, for example, li ₇ La ₃ Zr ₂ O ₁₂ Or Li (lithium) _6.5 La ₃ Zr _1.5 Ta _0.5 O ₁₂ 。

In embodiments, the solid electrolyte may be, for example, sulfide-based solid electrolysisQuality is high. The sulfide-based solid electrolyte may be, for example, li ₂ S-P ₂ S ₅ Li wherein X is halogen ₂ S-P ₂ S ₅ -LiX，Li ₂ S-P ₂ S ₅ -Li ₂ O，Li ₂ S-P ₂ S ₅ -Li ₂ O-LiI，Li ₂ S-SiS ₂ ，Li ₂ S-SiS ₂ -LiI，Li ₂ S-SiS ₂ -LiBr，Li ₂ S-SiS ₂ -LiCl，Li ₂ S-SiS ₂ -B ₂ S ₃ -LiI，Li ₂ S-SiS ₂ -P ₂ S ₅ -LiI，Li ₂ S-B ₂ S ₃ Li wherein m and n are positive integers and Z is Ge, zn, or Ga ₂ S-P ₂ S ₅ -Z _m S _n ，Li ₂ S-GeS ₂ ，Li ₂ S-SiS ₂ -Li ₃ PO ₄ Li wherein p and q are positive integers and M is P, si, ge, B, al, ga, or In ₂ S-SiS ₂ -Li _p MO _q Li, wherein 0.ltoreq.x.ltoreq.2 _7-x PS _6-x Cl _x Li, wherein 0.ltoreq.x.ltoreq.2 _7-x PS _6-x Br _x Li, wherein 0.ltoreq.x.ltoreq.2 _7- _x PS _6-x I _x Or a combination thereof. The sulfide-based solid electrolyte may be prepared by reacting a starting material (e.g., li ₂ S or P ₂ S ₅ ) Is prepared by a melt quenching method or a mechanical grinding method. Subsequently, it may be subjected to a heat treatment. The sulfide-based solid electrolyte may be an amorphous sulfide solid electrolyte, a crystalline sulfide solid electrolyte, or a mixture thereof.

Further, the sulfide-based solid electrolyte may include, for example, at least sulfur (S), phosphorus (P), and lithium (Li) as constituent elements of the above sulfide-based solid electrolyte material. For example, the sulfide-based solid electrolyte may be a solid electrolyte including Li ₂ S-P ₂ S ₅ Is a material of (3). When comprising Li ₂ S-P ₂ S ₅ When used as a sulfide-based solid electrolyte material, li ₂ S vs P ₂ S ₅ Can be, for example, li ₂ S:P ₂ S ₅ =50:50 to 90:10.

The sulfide solid electrolyte may be a solid electrolyte including Li _7-x PS _6-x Cl _x (0≤x≤2)、Li _7-x PS _6-x Br _x (0≤x≤2)、Li _7-x PS _6-x I _x (x is more than or equal to 0 and less than or equal to 2), or a combination thereof. The sulfide-based solid electrolyte included in the solid electrolyte may be a solid electrolyte including Li ₆ PS ₅ Cl、Li ₆ PS ₅ Br、Li ₆ PS ₅ I. Or combinations thereof.

The solid electrolyte 30 may further include, for example, a binder. The binder included in the solid electrolyte 30 may be, for example, styrene Butadiene Rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, or polyethylene. The embodiments are not limited thereto. Any suitable binder available in the art may be used. The binder of the solid electrolyte 30 may be the same as or different from the binder of the positive electrode active material layer 12 and the binder of the negative electrode active material layer 22.

Negative electrode

As shown in fig. 14, the anode 20 may include an anode current collector 21, a second anode active material layer 24, a first anode active material layer 23, and an intermediate layer 22.

For example, the negative electrode current collector 21 may include the following materials: the material is not reactive with lithium and does not form an alloy or compound with lithium. The material of the negative electrode current collector 21 may include, for example, copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), and nickel (Ni). But the embodiment is not limited thereto. Any suitable electrode current collector available in the art may be used. Negative electrode current collector 21 may include one type of the above-described metals, or an alloy of at least two metals or a coating material. The negative electrode current collector 21 may be, for example, a plate shape or a foil shape.

As shown in fig. 14, in the all-solid secondary battery 1 according to the embodiment, the second anode active material layer 24 may be between the anode current collector 21 and the first anode active material layer 23.

The second anode active material layer 24 may be between the anode current collector 21 and the first anode active material layer 23, and may include lithium metal or a lithium alloy.

Examples of the lithium alloy may include a Li-Ag alloy, a Li-Au alloy, a Li-Al alloy, a Li-Sn alloy, a Li-In alloy, a Li-Zn alloy, a Li-Ge alloy, or a Li-Si alloy, but the embodiment is not limited thereto.

The second anode active material layer 24 may be prepared at the time of assembling the battery, or may be formed as a precipitation layer after charging a battery that does not include the second anode active material layer at the time of assembling the battery.

As described above, the second anode active material layer 24 includes one metal, two or more metal composites, or metal alloys, lithium alloys, or lithium that can form an alloy phase with lithium without including lithium metal. Examples of the second anode active material layer 24 include Ag, sn-Si alloy, ag-Sn alloy, a combination thereof, or a combination of lithium and the foregoing metals.

The lithium metal may include lithium, and the lithium alloy may be, for example, a Li-Al alloy, a Li-Sn alloy, a Li-In alloy, a Li-Ag alloy, a Li-Au alloy, a Li-Zn alloy, a Li-Ge alloy, or a Li-Si alloy, but the embodiment is not limited thereto. Any suitable lithium alloy useful in the art as a lithium alloy may be used.

The second anode active material layer 24 may include one of the alloys, lithium metal, or several types of alloys.

The intermediate layer 22 may form an interface having superior adhesion to the solid electrolyte compared to the first anode active material layer.

In particular, the intermediate layer 22 may contain the third metal material, and the third metal material has excellent adhesion to the oxide-based solid electrolyte, and may not serve as a resistance (resistance) element to movement of lithium ions.

The third metal (M3) of the intermediate layer 22 may contain the same metal as the first anode active material layer 23. The method of manufacturing the all-solid secondary battery 1 may include: providing a positive electrode; disposing a solid electrolyte on the positive electrode; providing an intermediate layer on a first surface of the solid electrolyte opposite a second surface of the solid electrolyte on which the positive electrode is provided; disposing the first anode active material layer on the intermediate layer and opposite to the solid electrolyte; and disposing the anode current collector on the first anode active material layer opposite to the intermediate layer to prepare the all-solid secondary battery, wherein the first anode active material layer may include a mixture of a compound of formula 1 and a compound of formula 2, a complex of a compound of formula 1 and a compound of formula 2, or a combination thereof,

1 (1)

Li _x M1 _y

Wherein in formula 1, the first metal (M1) may be an element capable of forming a compound or alloy with lithium and oxygen, and

2, 2

M2 _a N _b

Providing the intermediate layer and the first anode active material layer (wherein the intermediate layer and the first anode active material layer may be formed simultaneously by one process) may include: depositing a first metal on the solid electrolyte under a nitrogen atmosphere to form a first layer including a first metal nitride layer, and contacting the first layer with lithium, charging an all-solid secondary battery to supply lithium to the first layer, heat-treating the first layer, or a combination thereof to simultaneously form the intermediate layer and the first anode active material layer.

In this specification, the meaning of "using the first layer" should be interpreted to include all of the following: wherein i) the first layer is in contact with lithium stacked on top of the first layer, ii) lithium is supplied to the first layer after charging, or iii) the first layer is heat treated (e.g., at 100 ℃ for about 10 minutes).

When the first anode active material layer further includes an oxide such as a compound of formula 3, the first metal may be deposited on top of the solid electrolyte in a mixed atmosphere of nitrogen and oxygen to form a first layer including a structure of a first metal nitride and oxide. Here, the structure of the first metal nitride and oxide is, for example, a mixture of the first metal nitride and oxide, a composite of the first metal nitride and oxide composite, or a combination thereof. For example, the first metal nitride and oxide structure is a mixture of the first metal nitride and oxide.

Providing the intermediate layer and the first anode active material may include: an intermediate layer is formed on the solid electrolyte, and the first anode active material layer is formed on top of the intermediate layer opposite to the solid electrolyte.

Providing the intermediate layer and the first anode active material layer may include: disposing the first metal on the solid electrolyte under an oxygen atmosphere to form a second layer including a first metal oxide layer and thereby form the intermediate layer; and depositing the first metal on the second layer under a nitrogen atmosphere to form a first layer including a first metal nitride layer and thereby form the first anode active material layer. The first metal, the second metal, and the third metal may be the same.

The second anode active material layer may be further included between the anode current collector and the first anode active material layer.

The second anode active material layer may include a fourth metal, and the fourth metal may include lithium, silver (Ag), tin (Sn), indium (In), silicon (Si), gallium (Ga), aluminum (Al), titanium (Ti), zirconium (Zr), niobium (Nb), germanium (Ge), antimony (Sb), bismuth (Bi), zinc (Zn), gold (Au), platinum (Pt), palladium (Pd), nickel (Ni), iron (Fe), cobalt (Co), chromium (Cr), magnesium (Mg), cesium (Cs), cerium (Ce), lanthanum (La), tungsten (W), tellurium (Te), lithium alloy, or a combination thereof, wherein the fourth metal is an element of groups 2 to 15. The fourth metal may include silver (Ag), tin (Sn), indium (In), silicon (Si), gallium (Ga), aluminum (Al), titanium (Ti), zirconium (Zr), niobium (Nb), germanium (Ge), antimony (Sb), bismuth (Bi), zinc (Zn), gold (Au), platinum (Pt), palladium (Pd), nickel (Ni), iron (Fe), cobalt (Co), chromium (Cr), magnesium (Mg), cesium (Cs), cerium (Ce), lanthanum (La), tungsten (W), tellurium (Te), or a combination thereof.

The second anode active material layer may be formed as a precipitation layer during charging of an all-solid secondary battery, during disposing the anode current collector on the first anode active material layer, or during both the charging and disposing the anode current collector on the first anode active material layer, and the second anode active material layer may be lithium metal, a lithium alloy, or a combination thereof.

The fourth metal may include: lithium, silver (Ag), tin (Sn), indium (In), silicon (Si), gallium (Ga), aluminum (Al), titanium (Ti), zirconium (Zr), niobium (Nb), germanium (Ge), antimony (Sb), bismuth (Bi), zinc (Zn), gold (Au), platinum (Pt), palladium (Pd), nickel (Ni), iron (Fe), cobalt (Co), chromium (Cr), magnesium (Mg), cesium (Cs), cerium (Ce), lanthanum (La), tungsten (W), tellurium (Te), or combinations thereof; and lithium alloys, such as lithium in combination with: silver (Ag), tin (Sn), indium (In), silicon (Si), gallium (Ga), aluminum (Al), titanium (Ti), zirconium (Zr), niobium (Nb), germanium (Ge), antimony (Sb), bismuth (Bi), zinc (Zn), gold (Au), platinum (Pt), palladium (Pd), nickel (Ni), iron (Fe), cobalt (Co), chromium (Cr), magnesium (Mg), cesium (Cs), cerium (Ce), lanthanum (La), tungsten (W), tellurium (Te), or combinations thereof.

The first metal oxide may be, for example, tin oxide, silver oxide, zinc oxide, silicon oxide, germanium oxide, tellurium oxide, aluminum oxide, gallium oxide, bismuth oxide, antimony oxide, or the like.

The first metal nitride may be, for example, tin nitride, silver nitride, zinc nitride, silicon nitride, germanium nitride, tellurium nitride, aluminum nitride, gallium nitride, bismuth nitride, antimony nitride, or a combination thereof.

The first metal of the first anode active material layer may be alloyed with lithium during charging, during disposing the anode current collector on the first anode active material layer, or during disposing the second anode active material layer, or during both charging and disposing the anode current collector on the first anode active material layer or the second anode active material layer.

The method may further include disposing (e.g., bonding) the second anode active material layer on the first anode active material layer by pressing. During pressurization, a portion of lithium included in the second anode active material layer may be injected into the first anode active material layer.

The second anode active material layer may be a lithium precipitation layer, which may prevent direct contact between the solid electrolyte and lithium metal by inducing precipitation of lithium metal on the anode current collector 21.

The second anode active material layer may be a third metal or lithium metal coated on the anode current collector 21. In an embodiment, the second anode active material layer may be a lithium metal or a lithium alloy layer precipitated upon charging. Lithium precipitation may increase the volume and thickness of the second anode active material layer during charging of the battery. In addition, the third metal may form a Li-M3 alloy through a reversible reaction during a charging and discharging process of the all-solid secondary battery. The second anode active material layer may be formed as a precipitation layer or a deposition layer during charging of the all-solid secondary battery, during assembly (e.g., disposing or bonding the aforementioned layers on another layer, or bonding the aforementioned layers to another layer), or during both charging and assembly, and may be a lithium metal layer or a lithium metal alloy layer.

The fourth metal in the second anode active material layer may form an alloy with lithium during charging, during assembly, or both charging and assembly of the all-solid secondary battery.

The method may further include disposing, for example, bonding, the second anode active material layer on the first anode active material layer, the intermediate layer, and the electrolyte assembly by pressing. During pressurization, a portion of lithium included in the second anode active material layer may be injected into the intermediate layer or the first anode active material layer.

The setting (e.g., combining) may be a compression-compression process. During pressurization, a portion of lithium included in the second anode active material layer may be injected into the first anode active material layer and/or the intermediate layer.

According to an embodiment, the second anode active material layer may be formed as a precipitation layer during charging, during assembly, or during both charging and assembly of the all-solid secondary battery. The second anode active material layer may be a lithium metal layer or a lithium metal alloy layer. The thickness of the second anode active material layer may be, for example, 1 μm or more, 5 μm or more, 10 μm or more, about 10 μm to about 1,000 μm, about 10 μm to about 500 μm, about 10 μm to about 200 μm, about 10 μm to about 100 μm, or about 10 μm to about 50 μm.

Preparation of the Positive electrode

First, a material constituting the positive electrode active material layer, for example, a positive electrode active material, a binder, may be added to a nonpolar solvent to thereby prepare a slurry. The prepared slurry may be coated on the positive electrode current collector 11 and then dried. The resulting laminate may be pressurized to prepare the positive electrode 10. The pressurization may be performed by, for example, rolling, flat pressing, pressing using hydrostatic pressure (hydrostatic pressure), or the like, but the embodiment is not limited thereto. Any suitable pressurization available in the art may be used. The description may be omitted. The positive electrode 10 may be molded in a disc shape or a sheet shape by compressing a mixture of materials constituting the positive electrode active material layer 12. When the positive electrode 10 is prepared as above, the positive electrode current collector 11 may be omitted. In an embodiment, the positive electrode 10 may be impregnated in an electrolyte to be used.

Preparation of solid electrolyte

The solid electrolyte 30 including the oxide-based solid electrolyte may be prepared, for example, by heat-treating a precursor of the oxide-based solid electrolyte material.

The oxide-based solid electrolyte may be prepared by: the precursors are contacted in stoichiometric amounts to form a mixture, which is then heat treated. The contacting may include milling or grinding, such as ball milling. The precursor mixture mixed in a stoichiometric composition may be subjected to a primary heat treatment in an oxidizing atmosphere to produce a primary heat treated product. The primary heat treatment may be performed at a temperature range of about 1,000 ℃ or less for about 1 hour to about 36 hours. The product of the primary heat treatment may be ground. The grinding of the product obtained by the primary heat treatment may be carried out dry or in wet. For example, wet milling may be performed by: a solvent (e.g., methanol) and the resulting product of the primary heat treatment are mixed and then milled with a ball mill for about 0.5 hours to about 10 hours. Dry milling may be performed by milling with a ball mill in the absence of solvent. The diameter of the product resulting from the primary heat treatment after grinding may be in the range of about 0.1 μm to about 10 μm, or about 0.1 μm to about 5 μm. The milled primary heat treated product may be dried. The resulting product of the initial heat treatment after grinding may be mixed with a binder solution and molded into a wafer, or simply pressed and molded into a wafer at a pressure in the range of about 1 ton to about 10 tons.

The molded result may be subjected to a secondary heat treatment at a temperature of about 1,500 ℃ or less for about 1 hour to about 36 hours. The sintered product, the solid electrolyte 30, can be obtained by a secondary heat treatment. The secondary heat treatment may be performed at, for example, about 500 ℃ to about 1,300 ℃, about 550 ℃ to about 1,200 ℃, or about 550 ℃ to about 1,000 ℃. The secondary heat treatment may be performed for about 1 hour to about 36 hours. To obtain a sintered product, the secondary heat treatment temperature is greater than the primary heat treatment temperature. For example, the secondary heat treatment temperature may be about 10 ℃ or greater, about 20 ℃ or greater, about 30 ℃ or greater, or about 50 ℃ or greater than the primary heat treatment temperature. The molded result may be subjected to a secondary heat treatment in at least one of an oxidizing atmosphere and a reducing atmosphere. The secondary heat treatment may be performed in a) an oxidizing atmosphere, b) a reducing atmosphere, or c) an oxidizing atmosphere and a reducing atmosphere.

The solid electrolyte 30 including the sulfide-based solid electrolyte may be prepared, for example, by using a solid electrolyte formed of a sulfide-based solid electrolyte material.

Regarding the sulfide-based solid electrolyte, the starting material may be treated by, for example, a melt quenching method or a mechanical grinding method, but the embodiment is not necessarily limited thereto. Any suitable method available in the art as a method for preparing the sulfide-based solid electrolyte may be used. For example, when using melting In the quenching method, first, li may be added ₂ S and P ₂ S ₅ Mix in a given ratio and compress the mixture into a disc. The wafer may then be treated in vacuo at a given reaction temperature and quenched to produce a sulfide-based solid electrolyte material. In this regard, li ₂ S and P ₂ S ₅ The reaction temperature of the mixture of (a) may be in the range of about 400 ℃ to about 1000 ℃, for example, in the range of about 800 ℃ to about 900 ℃. The reaction time may be, for example, from about 0.1 hours to about 12 hours, or from about 1 hour to about 12 hours. Further, the temperature during quenching of the reactants may be about 10 ℃ or less, such as about 0 ℃ or less, and the quenching rate may be in the range of about 1 ℃/sec to about 10,000 ℃/sec, such as about 1 ℃/sec to about 1,000 ℃/sec. For example, when a mechanical milling method is used, the starting material (e.g., li ₂ S or P ₂ S ₅ Stirring and reacting to prepare the sulfide-based solid electrolyte material. Although the stirring rate and duration of the mechanical milling method are not particularly limited, as the stirring rate increases, the production rate of the sulfide-based solid electrolyte material may increase, and as the stirring duration increases, the conversion rate of the raw material to the sulfide-based solid electrolyte material may increase. Subsequently, the mixed raw material prepared by the melt quenching method or the mechanical milling method may be heat-treated and milled at a given temperature to prepare a solid electrolyte in the form of particles. In the case where the solid electrolyte has a glass transition property, the solid electrolyte may be crystallized due to heat treatment.

The resulting solid electrolyte may be used to form the solid electrolyte 30 by any suitable method for forming a layer, such as deposition, aerosol deposition, cold spray, or sputtering. In addition, the solid electrolyte 30 may be prepared by pressurizing solid electrolyte particles. In addition, the solid electrolyte 30 may be prepared by: the solid electrolyte, the solvent, and the binder are mixed, followed by coating, drying, and pressurizing.

Preparation of all-solid secondary battery

An assembly of the anode 20 and the solid electrolyte 30, and the cathode 10 may be prepared, and then the solid electrolyte 30 may be interposed between the cathode 10 and the anode 20, followed by pressurization, thereby completing the manufacture of the all-solid secondary battery 1.

The pressing may be, for example, rolling, uniaxial pressing, flat pressing, warm Isostatic Pressing (WIP), cold Isostatic Pressing (CIP), but is not necessarily limited thereto. Any suitable pressurizing method available in the art may be used. The pressure applied during pressurization may be, for example, about 50 megapascals (MPa) to about 750MPa. The time for which the pressure is applied may be in the range of about 5 milliseconds (ms) to about 5 minutes (min). The pressurization may be performed at, for example, room temperature to temperature 90 ℃ or less, or at about 20 ℃ to about 90 ℃. In embodiments, the pressurizing may be performed at an elevated temperature of 100 ℃ or greater.

Next, the positive electrode 10 may be placed on the other surface of the solid electrolyte 30 opposite to the surface on which the negative electrode 20 is bonded, and pressurized at a given pressure to dispose (e.g., bond) the positive electrode 10 to the other surface of the solid electrolyte layer 30. In an embodiment, when the positive electrode 10 is impregnated with a liquid electrolyte, a battery may be manufactured by lamination without pressure.

The pressing may be, for example, rolling, uniaxial pressing, flat pressing, warm Isostatic Pressing (WIP), cold Isostatic Pressing (CIP), but is not necessarily limited thereto. Any suitable pressurizing method available in the art may be used. The pressure applied during pressurization may be, for example, about 50MPa to about 750MPa. The time for applying pressure may be between about 5ms and about 5 minutes. The pressurization may be performed at, for example, room temperature to temperature 90 ℃ or less, or at about 20 ℃ to about 90 ℃. In embodiments, the pressurizing may be performed at an elevated temperature of 100 ℃ or greater.

According to another embodiment, an all-solid secondary battery may include a positive electrode and the negative electrode-solid electrolyte proton assembly disposed on the positive electrode, and wherein the solid electrolyte may be located between the positive electrode and the negative electrode.

The positive electrode may contain a liquid electrolyte.

The anode-solid electrolyte proton assembly according to an embodiment may include: a negative electrode current collector; a first anode active material layer disposed on the anode current collector; an intermediate layer disposed on the first anode active material layer and opposite to the anode current collector; and a solid electrolyte disposed on the intermediate layer and opposite to the first anode active material layer,

wherein the first anode active material layer may include: a mixture of a compound of formula 1 and a compound of formula 2, a complex of a compound of formula 1 and a compound of formula 2, or a combination thereof:

1 (1)

Li _x M1 _y

2, 2

M2 _a N _b

wherein the intermediate layer comprises a third metal material, and

the third metal material includes a third metal oxide, an oxide including a third metal and lithium, a lithium oxide, or a combination thereof, wherein the third metal is a group 2 to 15 element.

The arrangement and the manufacturing method of the above-described all-solid secondary battery 1 are example embodiments, and elements and manufacturing procedures may be appropriately changed. Pressurization may be omitted.

Hereinafter, the inventive concept will be described in detail with reference to examples and comparative examples. These examples are for illustrative purposes only and are not intended to limit the scope of the inventive concept.

Examples

Example 1: LCO (3.2 milliampere hour per square centimeter (mAh/cm) ² ))/LLZTO/Li _a Sn _b O _c +Sn _a O _b composite/Li of (2) _x Sn _y (wherein 0<x.ltoreq.5 and y=1) +Li _a N _b (wherein 0<a<6 and is provided withb=1) composite/Li metal

Preparation of solid electrolyte/negative electrode laminate

LLZTO (Li) _6.5 La ₃ Zr _1.5 Ta _0.5 O ₁₂ ) The wafer acts as a solid electrolyte.

Depositing Sn on the solid electrolyte at a temperature of 25 ℃ in a nitrogen atmosphere to form Sn having a thickness of about 115nm ₃ N ₄ A layer. Then, sn is added ₃ N ₄ The layers were immersed in 0.1M aqueous HCl for 10 seconds. Then, the resultant immersed in HCl was dried at a temperature of 25 ℃ to sequentially form a pre-interlayer (i.e., sn-Ox (0 therein)<x.ltoreq.6) composite layer) and a pre-first anode active material layer (i.e., sn-Nx (0 therein)<x.ltoreq.6) composite layer), thereby producing a solid electrolyte/pre-interlayer/pre-first anode active material layer laminate.

A second anode active material layer was laminated on the solid electrolyte/pre-interlayer/pre-first anode active material layer laminate, in which a copper (Cu) foil as an anode current collector having a thickness of 10 μm was coated with lithium (Li) metal having a thickness of 20 μm. Then, a pressure of 100MPa was applied thereto by Cold Isostatic Pressing (CIP) at a temperature of 25 ℃, thereby producing a negative electrode-solid electrolyte proton assembly having a stacked structure of a solid electrolyte/an intermediate layer/a first negative electrode active material layer/a second negative electrode active material layer/a negative electrode current collector.

Preparation of the Positive electrode

Preparation of LiCoO ₂ (LCO) as a positive electrode active material. In addition, polytetrafluoroethylene (DuPont ^TM Teflon binder) as binder. The binder was used in the form of a solution (dissolved in N-methyl-2-pyrrolidone (NMP) at a ratio of 5 wt%). In addition, denka Black (DB) was also prepared as a conductive aid.

Then, these materials were mixed in a weight ratio of positive electrode active material: conductive auxiliary agent: binder=100:2:1 to prepare a slurry type mixture. The slurry type mixture was coated on a positive electrode current collector including an aluminum foil 18 μm thick, and the coated positive electrode current collector was dried at 120 ℃ for 12 hours and compressed to manufacture a positive electrode.

The prepared positive electrode active material layer of the positive electrode was immersed in an electrolyte solution of bis (fluorosulfonyl) imide N-propyl-N-methyl-pyrrolidinium (PYR 13 FSI) ionic liquid in which 2.0M of lithium bis (trifluoromethylsulfonyl) imide (LiTFSI) was dissolved.

Preparation of all-solid secondary battery

The positive electrode was placed such that the positive electrode active material layer immersed in the electrolyte solution containing the ionic liquid faced the top in a stainless steel (SUS) cap. An all-solid secondary battery was manufactured by: the solid electrolyte/anode laminate having the anode attached to the laminate is placed such that the solid electrolyte is disposed on the positive electrode active material layer, and the structure is sealed. The positive electrode and the negative electrode are insulated with an insulator. A part of the positive electrode current collector and a part of the negative electrode current collector protrude to the outside of the sealed battery and are used as a positive electrode terminal and a negative electrode terminal, respectively.

When the thus obtained all-solid secondary battery was charged as in evaluation example 4, the intermediate layer included a battery containing Li _a Sn _b O _c (wherein 0<a≤9、0<b is less than or equal to 3 and 0<c.ltoreq.7) and Sn _a O _b (wherein 0<a is less than or equal to 3 and 0<b.ltoreq.4). Li (Li) _a Sn _b O _c (wherein 0<a≤9、0<b is less than or equal to 3 and 0<Examples of c.ltoreq.7) are Li ₂ SnO ₃ And Sn is _a O _b (wherein 0 <a is less than or equal to 3 and 0<Examples of b.ltoreq.4) are SnO ₂ . The thickness of the intermediate layer is about 15nm.

The first anode active material layer includes Li _x Sn _y (wherein 0<x.ltoreq.5 and y=1) and Li _a N _b (wherein 0<a<6 and b=1), and the thickness of the first anode active material layer is about 100nm. In Li _x Sn _y (wherein 0<x.ltoreq.5 and y=1) and Li _a N _b (wherein 0<a<6 and b=1), li _x Sn _y Examples of (1) are Li ₃ Sn, and Li _a N _b Examples of (1) are Li ₃ N。

The composition of the first anode active material layer and the intermediate layer was confirmed by using XPS analysis.

As Li-containing _a Sn _b O _c (wherein 0<a≤9、0<b is less than or equal to 3 and 0<c.ltoreq.7) and Sn _a O _b (wherein 0<a is less than or equal to 3 and 0<As a result of XPS analysis of the complex of b.ltoreq.4), a Sn 3d peak appears at the binding energy of 485-490 eV. With Li _a Sn _b O _c And Sn (Sn) _a O _b The Sn 3d peak of XPS analysis of the complex shows a shift to higher binding energy than the result of XPS analysis of the mixture.

As Li-containing _x Sn _y (wherein 0<x.ltoreq.5 and y=1) and Li _a N _b (wherein 0<a<As a result of XPS analysis of the complex of 6 and b=1), a Sn 3d peak appears at a binding energy of 485-490 eV. With Li _x Sn _y And Li (lithium) _a N _b The Sn 3d peak of XPS analysis of the complex shows a shift to high binding energy compared to the result of XPS analysis of the mixture.

Example 2: LCO (3.2 mAh/cm) ² ) LLZTO/Li-Cu-O+CuOx composite layer (Li) _a Cu _b O _c And Cu _a O _b Composite of (2)/Li+Cu ₃ N+Li ₃ N/Li metal

An all-solid secondary battery was manufactured in the same manner as in example 1, except that: a laminate of the solid electrolyte/pre-intermediate layer/pre-first anode active material layer was prepared as follows.

Copper was deposited on the solid electrolyte at a temperature of 25 ℃ in an oxygen atmosphere by using RF sputtering to form a pre-interlayer (i.e., cuOx (0 therein)<x<3) Layer) to prepare a solid electrolyte/pre-interlayer. Subsequently, copper is deposited on the resulting structure at a temperature of 25 ℃ in a nitrogen atmosphere to form Cu ₃ N, thereby preparing a laminate of a solid electrolyte/a pre-interlayer/a pre-first anode active material layer.

When the all-solid secondary battery prepared in example 2 was charged as in evaluation example 4, the first anode active material layer contained Li, cu ₃ N and Li ₃ N complexA compound, and the intermediate layer comprises Li _a Cu _b O _c (wherein 0<a≤9、0<b is less than or equal to 3 and 0<c.ltoreq.7) and Cu _a O _b (wherein 0<a is less than or equal to 5 and 0<b.ltoreq.24). The thickness of the intermediate layer prepared in example 2 was about 15nm, and the thickness of the first anode active material layer was about 100nm.

Example 3: LCO (3.2 mAh/cm) ² )/LLZTO/Li _a Sn _b O _c (wherein 0<a≤9、0<b is less than or equal to 3 and 0<c.ltoreq.7) and Sn _a O _b (wherein 0<a is less than or equal to 3 and 0<b.ltoreq.4) complex/Li _x Sn _y (wherein 0<x is less than or equal to 5 and y=1), sn _a N _b (wherein 0<a is less than or equal to 3 and 0<b.ltoreq.4, e.g. Sn ₃ N ₄ ) And Sn _a O _b (0<a≤3、0<b.ltoreq.4, e.g. SnO ₂ ) Is a complex of (2) and Li metal

Sn is deposited on the solid electrolyte in an oxygen atmosphere at a temperature of 25 ℃ to form a pre-interlayer (i.e., snOx (where 0< x+.6)) having a thickness of 10 nm. Then, sn was deposited to a thickness of 100nm in a mixed gas atmosphere of oxygen and nitrogen to sequentially form a pre-first anode active material layer (i.e., sn-O-N composite layer), thereby preparing a solid electrolyte/pre-intermediate layer/pre-first anode active material layer laminate.

A second anode active material layer was stacked on the solid electrolyte layer/pre-interlayer/pre-first anode active material layer laminate, in which a copper (Cu) foil having a thickness of 10 μm as an anode current collector was coated with lithium (Li) metal having a thickness of 20 μm. Then, a pressure of 100MPa was applied thereto at a temperature of 25 ℃ by CIP, thereby preparing a negative electrode-solid electrolyte proton assembly having a stacked structure of a solid electrolyte/an intermediate layer/a first negative electrode active material layer/a second negative electrode active material layer/a negative electrode current collector.

Example 4: LCO (3.2 milliampere hour per square centimeter (mAh/cm) ² ))/LLZTO/Li _a Sn _b O _c +Sn _a O _b composite/Li of (2) _x Sn _y (wherein 0<x.ltoreq.5 and y=1) +Li _a N _b (wherein 0<a<6 and b=1) composite/Li metal

An all-solid secondary battery was manufactured in the same manner as in example 1, except that: a solid electrolyte/anode laminate was prepared according to the following procedure.

Sn is deposited on the solid electrolyte in a nitrogen atmosphere at a temperature of 25 ℃, and then Sn is deposited on the solid electrolyte in a nitrogen atmosphere at a temperature of 25 ℃. The resulting structure was then immersed in 0.1M aqueous HCl for 10 seconds. Then, the resultant impregnated in HCl was dried at a temperature of 25 ℃ to sequentially form a pre-intermediate layer (i.e., sn-Ox (where 0< x.ltoreq.6) composite layer) and a pre-first anode active material layer (i.e., sn-Nx (where 0< x.ltoreq.6) composite layer) on the solid electrolyte, thereby preparing a solid electrolyte/pre-intermediate layer/pre-first anode active material layer laminate.

A second anode active material layer was stacked on the solid electrolyte/pre-interlayer/pre-first anode active material layer laminate, in which a copper (Cu) foil having a thickness of 10 μm as an anode current collector was coated with lithium (Li) metal having a thickness of 20 μm. Then, a pressure of 100MPa was applied thereto by Cold Isostatic Pressing (CIP) at a temperature of 25 ℃, thereby producing a negative electrode-solid electrolyte proton assembly having a stacked structure of a solid electrolyte/an intermediate layer/a first negative electrode active material layer/a second negative electrode active material layer/a negative electrode current collector.

Comparative example 1: LCO (3.2 mAh/cm) ² ) LLZTO/Li-Sn-O+LiSn composite layer/Li metal

An all-solid secondary battery was manufactured in the same manner as in example 1, except that: a laminate of the solid electrolyte-anode sub-assembly was prepared as follows.

Sn was deposited on the solid electrolyte by RF sputtering at a temperature of 25 ℃ in an oxygen atmosphere to form a SnO layer, thereby producing a solid electrolyte/SnO layer laminate.

A second anode active material layer was stacked on the solid electrolyte/pre-interlayer laminate, in which a copper (Cu) foil having a thickness of 10 μm as an anode current collector was coated with metallic lithium (Li) having a thickness of 20 μm. Then, a pressure of 100MPa was applied thereto at a temperature of 25 ℃ by CIP, thereby preparing a negative electrode-solid electrolyte proton assembly having a stacked structure of a solid electrolyte layer/an intermediate layer/a second negative electrode active material layer/a negative electrode current collector.

After charging and discharging the all-solid secondary battery prepared according to comparative example 1, the intermediate layer having a thickness of about 500nm contained Li-Sn-O and LiSn.

When prepared according to comparative example 1, the thickness of the intermediate layer increased. As can be seen from the results of the evaluation examples, since the first anode active material layer was not present, the resistance increased, and the high rate characteristics decreased.

Comparative example 2: LCO (3.2 mAh/cm) ² ) LLZTO/Li-Sn-O+SnOx composite layer/Li metal

An all-solid secondary battery was manufactured in the same manner as in comparative example 1, except that: the intermediate layer including Li-Sn-O and LiSn is formed to have a thickness of about 15 nm.

In the all-solid secondary battery prepared in comparative example 2, the first anode active material layer was not included. Therefore, as shown by the results in the evaluation examples, the magnification capability is deteriorated.

Comparative example 3: LCO (3.2 mAh/cm) ² )/LLZTO/LiZn _x (wherein 0<x≤3)+Li _y O (0 therein)<y.ltoreq.2) composite layer/Li metal

An all-solid secondary battery was manufactured in the same manner as in comparative example 1, except that: the solid electrolyte/pre-interlayer was prepared as follows.

Zn was deposited on the solid electrolyte by RF sputtering at a temperature of 25℃in an argon atmosphere to form a Zn layer having a thickness of about 50nm, thereby preparing a solid electrolyte/Zn layer laminate.

After charging and discharging the all-solid secondary battery prepared according to comparative example 3,the intermediate layer having a thickness of about 100nm contains LiZn _x (wherein 0<x.ltoreq.3) and Li _y O (0 therein)<y≤2)。

According to comparative example 3, the negative electrode active material was present in the intermediate layer [ (] _x LiZn，0<x≤3). Thus, electron conduction occurs, resulting in a short circuit.

Comparative example 4: LCO (3.2 mAh/cm) ² )/LLZTO/Te+LiTe _x (wherein 0<x≤3)+Li _y O (0 therein)<y.ltoreq.2) layer/Li metal

An all-solid secondary battery was manufactured in the same manner as in comparative example 1, except that: the solid electrolyte/pre-interlayer laminate was prepared as follows.

Te was deposited on the solid electrolyte by RF sputtering in argon (Ar) gas at a temperature of 25℃to form a Te layer having a thickness of about 100nm, thereby preparing a solid electrolyte/Te layer laminate.

After charging and discharging the all-solid secondary battery prepared according to comparative example 4, the intermediate layer contained Te, liTe having a thickness of about 30nm _x (wherein 0<x.ltoreq.3) and Li _y O (0 therein)<y≤2)。

According to comparative example 4, the negative electrode active material was present in the intermediate layer _x LiTe，0<x≤3). Thus, electron conduction occurs, resulting in a short circuit.

Comparative example 5: LCO (3.2 mAh/cm) ² ) Negative electrode with/LLZTO/Li metal structure

A second anode active material layer was stacked on the solid electrolyte, in which a copper (Cu) foil having a thickness of 10 μm as an anode current collector was coated with lithium (Li) metal having a thickness of 20 μm. Then, a pressure of 100MPa was applied thereto by CIP at a temperature of 25 ℃, thereby preparing a negative electrode-solid electrolyte proton assembly having a stacked structure of a solid electrolyte layer/a second negative electrode active material layer/a negative electrode current collector.

Evaluation example 1: TEM-EDS analysis

The all-solid secondary batteries prepared in examples 1 and 2 were charged, and the solid electrolyte-anode sub-assembly was subjected to transmission electron microscopy/energy dispersive X-ray spectrometry (TEM/EDS) analysis. The results of analysis of the solid electrolyte-anode subassembly of example 1 are shown in fig. 2A to 2E. The results of EDS analysis of the solid electrolyte-anode subassembly of example 1 are shown in fig. 4A to 4D. The results of EELS analysis on the solid electrolyte-anode subassembly of example 1 are shown in fig. 5A to 5D. The results of EDS mapping for an all-solid secondary battery including a negative electrode-solid electrolyte proton assembly according to example 2 are shown in fig. 6A to 6E.

As shown in fig. 2A to 2E, the first anode active material layer in the solid electrolyte-anode subassembly of example 1 contains tin and nitrogen, and an oxide layer is formed as an intermediate layer in contact with the solid electrolyte. As shown in fig. 4A to 4D, it was found that a layer including nitrogen was formed. As shown in fig. 5A to 5D, the layer including nitrogen was found to include lithium and tin.

As shown in fig. 6A to 6E, the first anode active material layer in the solid electrolyte-anode subassembly of example 2 contains copper, nitrogen, and oxygen, and an oxide layer having a thickness of 3 to 4nm is formed as an intermediate layer in contact with the solid electrolyte.

Evaluation example 2: evaluation of interfacial resistance

The interfacial resistances of the all-solid secondary batteries fabricated in examples 1 to 3 and comparative examples 1 to 5 were measured, respectively. The impedance of the respective discs of the all-solid secondary battery was measured in atmospheric conditions at a temperature of 25℃according to the 2-probe method using an impedance analyzer (Solartron 1400A/1455A). The frequency range is 0.1 hertz (Hz) to 1MHz and the amplitude voltage is 10 millivolts (mV).

Nyquist (Nyquist) plots of impedance measurements for the solid electrolyte-negative electrode sub-assemblies of examples 1 to 3 and comparative examples 1 to 5 are shown in fig. 3A, 7D, 9A, 10A, 11A and 12A, respectively.

As shown in fig. 3A, 7D, 9A, 10A, 11A, and 12A, the all-solid secondary batteries of examples 1, 2, and 3 were found to have significantly reduced interfacial resistance as compared with the all-solid secondary batteries of comparative examples 1 to 5.

Evaluation example 3: charge and discharge test (I)

The charge/discharge characteristics of all solid secondary batteries of examples 1 and 2 and comparative examples 1 to 5 were evaluated by the following charge/discharge test. In the charge/discharge test, charging and discharging were performed while changing the current density at a temperature of 25 ℃ in a voltage range of 4.5 volts (V) to 2.75V to confirm the driving characteristics of the all-solid secondary battery in a high current density state.

In order to confirm the operation characteristics of the all-solid secondary battery in the high current density state, charge and discharge tests of the all-solid secondary battery were performed at various current densities at a temperature of 25 c as shown in fig. 3B (example 1), 7B (example 2), 9B (comparative example 1), 10B (comparative example 2), 11B (comparative example 3), 12B (comparative example 4) and 13 (comparative example 5). Charge and discharge cycle tests were performed using a constant current method to confirm the short-circuit prevention property of the solid electrolyte and the effect of improving the battery performance. At this time, all negative electrode bonding was performed in the same manner using CIP.

Partial results of charge and discharge of the all solid secondary battery are shown in fig. 3B (example 1), 7B (example 2), 9B (comparative example 1), 10B (comparative example 2), 11B (comparative example 3), 12B (comparative example 4) and 13 (comparative example 5). As shown in fig. 3B and 7B, it was found that the all-solid secondary batteries of examples 1 and 2 were stably charged and discharged to 0.3 milliamp/square centimeter (mA/cm), respectively ² ) To 3.0mA/cm ² Without short-circuiting.

When the all-solid secondary battery of comparative example 1 did not contain the first anode active material layer and included a thick intermediate layer composed of an oxide and a metal, the interfacial resistance was 60 Ohm-square cm (Ohm cm ² ) Or greater and at 1.6mA/cm when the battery is charged and discharged by a constant current method at a temperature of 25 DEG C ² At a current density of 1mAh/cm ² Or lower discharge capacity, unlike the results of examples 1 and 2.

When the all-solid secondary battery of comparative example 2 did not contain the first anode active material layer and included an intermediate layer consisting of only an oxide, and when the battery was at 25 °cWhen charged and discharged by a constant current method at a temperature of 1.6mA/cm ² At a current density of 1mAh/cm ² Or lower discharge capacity, unlike the results of examples 1 and 2.

In the all-solid secondary battery of comparative example 3, the anode active material was present in the intermediate layer. Thus, electron conduction occurs, resulting in a short circuit. In the all-solid secondary battery of comparative example 4, as in comparative example 3, the presence of the metal in the intermediate layer caused electron conduction, and a short circuit was observed.

The all-solid secondary battery of comparative example 5 did not have an intermediate layer and a first anode active material layer, resulting in a short circuit.

In contrast, as shown in fig. 3B and 7B, it was found that all-solid secondary batteries of examples 1 and 2 were stably charged and discharged to 0.3mA/cm, respectively ² To 3.0mA/cm ² Without short-circuiting. Thus, it can be seen that the all-solid secondary batteries of examples 1 and 2 were more stable than the all-solid secondary batteries of comparative examples 1 to 5. Therefore, when the anode has the same multi-layered structure as in the all-solid secondary batteries of examples 1 and 2, the volume change that may occur during charge and discharge can be alleviated, and the local concentration of current at high current density can be reduced. Thus, the short circuit of the all-solid secondary battery is prevented.

Evaluation example 4: charge and discharge test (II)

The charge/discharge characteristics of the all-solid secondary batteries of examples 1 and 2 were evaluated by the following charge/discharge tests.

In the charge/discharge test, the charge and discharge of each all-solid secondary battery was performed at a temperature of 25 ℃ while changing the current density as shown in fig. 3B and 3C and fig. 7B and 7C to confirm the driving characteristics of the all-solid secondary battery in a high current density state. Fig. 3B and 3C are for example 1, and fig. 7B and 7C are for example 2. Charge and discharge cycle tests were performed using a constant current method to confirm the short-circuit prevention property of the solid electrolyte and the effect of improving the battery performance. At this time, all negative electrode bonding was performed in the same manner using CIP.

As shown in fig. 3B and 7B, examples 1 and 2All-solid secondary battery even at 3mA/cm ² Also shows stable charge and discharge characteristics at the current density of (C) and, as shown in fig. 3C and 7C, 50 charge and discharge cycles were performed without short circuit. Even at 3mA/cm ² Stable charge and discharge characteristics were also observed at the current density of (c). In this way, it was confirmed that the intermediate layer and the first anode active material layer were maintained stable during charge and discharge by controlling the lithium movement speed in the anode.

When the battery was charged and discharged using the constant current method at 25 ℃, the lithium diffusion at the interface was rapid, and in the case of the battery employing the multi-layered anode (example 1) which can maintain a stable interface even during discharge, even at 3mA/cm ² Also exhibit stable charging and discharging behavior at the current densities of (2). By using the first layer, the bonding strength with the second layer is increased, uniform lithium plating is performed using rapid diffusion in the second layer, and at this time, a lithium ion conductor such as nitride maintains a matrix structure to ensure durability of both layers, and the third layer serves as a site in which lithium can be easily precipitated. Therefore, lithium is stably deposited on the third layer even during repeated charge and discharge, preventing deterioration of the negative electrode and short-circuiting of the battery even during high-rate charge and discharge.

In addition, the charge and discharge characteristics of all solid-state secondary batteries of examples 3 to 4 were evaluated in the same manner as the evaluation method of the charge and discharge characteristics of all solid-state secondary batteries of example 1.

As a result of the evaluation, the charge and discharge characteristics of all solid-state secondary batteries of examples 3 to 4 were excellent even at 3mA/cm ² Shows stable charge and discharge at current density, is similar to that of the all-solid-state secondary battery of example 1, and performs 50 charge and discharge cycles without short circuit, and even at 3mA/cm ² Also shows stable charge and discharge at the current density of (c).

Evaluation example 5: XPS analysis

After reacting the precursor CuNx and Li for forming the first anode active material layer according to example 2, XPS analysis for the formation of the final second layer was performed, and the results of the analysis are shown in fig. 8A to 8C. Fig. 8A, 8B, and 8C are each XPS analysis results for Li, cu, and N, respectively.

As shown in fig. 8A and 8B, the presence of lithium and copper was confirmed. Furthermore, as shown in FIG. 8C, cu-N bond disappears, however Li is newly formed ₃ An N bond. Thus, it was confirmed that the first anode active material layer had LiCu and Li ₃ N complex composition.

When the first anode active material layer is a mixture of LiCu and LiN, the cu—n peak at the binding energy of 395-400eV shown in fig. 8C is absent or shifted to a lower binding energy.

Evaluation example 6: transmission electron microscopy-energy dispersive X-ray spectroscopy (TEM-EDS) and TEM-electron energy loss spectroscopy (TEM-EELS) analysis

The all-solid secondary battery prepared in example 1 was charged, and the cross section of the solid electrolyte/intermediate layer/first anode active material layer/second anode active material layer laminate was subjected to TEM/EDS and TEM/ELLS analysis. The results of TEM/EDS analysis of the solid electrolyte-anode subassembly of example 1 are shown in fig. 4A to 4D. The results of the TEM/EELS analysis of the solid electrolyte-anode subassembly of example 1 are shown in fig. 5A to 5D.

As shown in fig. 4A to 4D and 5A to 5D, according to embodiment 1, an intermediate layer (layer 1), a first anode active material layer (layer 2), and a second anode active material layer (layer 3) are sequentially formed between the solid electrolyte and the anode current collector. As shown in fig. 4B to 4D, it was found that the first anode active material layer contained nitrogen, the first anode active material layer and the intermediate layer contained tin (Sn), and the intermediate layer contained oxygen (O).

According to an embodiment, in the anode for an all-solid secondary battery, in order to prevent deterioration of the anode due to aggregation or volume expansion when reacting with lithium during charge and discharge of the battery and to prevent deterioration of rate characteristics due to slow lithium movement, a first anode active material layer containing nitride having a fast lithium movement speed may be introduced, and thus, lithium may be uniformly distributed and volume expansion may be alleviated. Therefore, an all-solid secondary battery having high rate characteristics and life characteristics can be manufactured.

It should be understood that the embodiments described herein should be considered in descriptive sense only and not for purposes of limitation. The descriptions of features or aspects in various embodiments should typically be considered as available for other similar features or aspects in other embodiments. Although one or more embodiments have been described with reference to the accompanying drawings, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope as defined by the following claims.

Claims

1. A negative electrode-solid electrolyte proton assembly for an all-solid secondary battery, comprising:

a negative electrode current collector;

a first anode active material layer disposed on the anode current collector;

an intermediate layer disposed on the first anode active material layer and opposite to the anode current collector; and

1 (1)

Li _x M1 _y

2, 2

M2 _a N _b

wherein the third metal is a group 2 to 15 element.

2. The anode-solid electrolyte proton assembly according to claim 1, wherein in formula 1, the first metal is aluminum, zinc, tin, silicon, germanium, copper, indium, gallium, titanium, zirconium, niobium, antimony, bismuth, gold, platinum, palladium, nickel, iron, cobalt, chromium, magnesium, cesium, cerium, silver, sodium, potassium, calcium, yttrium, tantalum, hafnium, barium, vanadium, strontium, tellurium, lanthanum, or a combination thereof, and in formula 2, the second metal is aluminum, zinc, tin, silicon, germanium, copper, indium, gallium, titanium, zirconium, niobium, antimony, bismuth, gold, platinum, palladium, nickel, iron, cobalt, chromium, magnesium, cesium, cerium, silver, sodium, potassium, calcium, yttrium, tantalum, hafnium, barium, vanadium, strontium, tellurium, lanthanum, or a combination thereof, or

Wherein the compound of formula 1 is Li ₃ Al，Li ₂ Zn，Li ₄ Sn, li in which x is 1.ltoreq.3 and y is 1.ltoreq.3 _X Si _y Li in which x is 1.ltoreq.3 and y is 1.ltoreq.3 _x Ge _y Li in which x is 1.ltoreq.3 and y is 1.ltoreq.3 _x Cu _y Wherein 0 is<x<Li of 5 _x Sn, 0 therein<x<Li of 5 _x Zn of 0<x<Li of 5 _x Al of 0<x<Li of 4 _x Sb of 0<x<Li of 5 _x Si of 0<x<Li of 5 _x Au, 0 of<x<Li of 10 _x Ag of 0<x<Li of 5 _x In, 0 therein<x<Li of 5 _x Bi of 0<x<Li of 5 _x Ga, 0 therein<x<Li of 5 _x Te of 0<x<Li of 5 _x Ge, 0 therein<x<L of 7 _ix Mg, or a combination thereof, and wherein the compound of formula 2 is Li ₃ N, wherein 1.ltoreq.a.ltoreq.3 and 1.ltoreq.b.ltoreq.4 _a N _b Zn in which a is 1-3 and b is 1-4 _a N _b Sn with a being 1-3 and b being 1-4 _a N _b Wherein a is 1-3 andsi with b being more than or equal to 1 and less than or equal to 4 _a N _b Wherein 1.ltoreq.a.ltoreq.3 and 1.ltoreq.b.ltoreq.4 _a N _b Cu in which a is 1-3 and b is 1-4 _a N _b In, wherein a is 1.ltoreq.a.ltoreq.3 and b is 1.ltoreq.b.ltoreq.4 _a N _b Ga in which a is 1.ltoreq.a.ltoreq.3 and b is 1.ltoreq.b.ltoreq.4 _a N _b Ti in which a is 1.ltoreq.a.ltoreq.3 and b is 1.ltoreq.b.ltoreq.4 _a N _b Zr with a being equal to or less than 1 and equal to or less than 3 and b being equal to or less than 1 and equal to or less than 4 _a N _b Nb in which a is 1.ltoreq.a.ltoreq.3 and b is 1.ltoreq.b.ltoreq.4 _a N _b Or a combination thereof, or

Wherein the compound of formula 2 is Li ₃ N，AlN，Zn ₃ N ₂ ，Sn ₃ N ₄ ，Si ₃ N ₄ ，Ge ₃ N ₄ ，Cu ₃ N, or a combination thereof.

3. The anode-solid electrolyte proton assembly according to claim 1, wherein the first anode active material layer further comprises a compound represented by formula 3:

3

M2 _a O _b

Wherein in formula 3, M2 is the second metal and is lithium, an element capable of forming a compound or alloy with lithium and nitrogen, or a combination thereof, and

4. The anode-solid electrolyte proton assembly according to claim 3, wherein in formula 3, the second metal is Al, zn, sn, si, ge, cu, in, ga, ti, zr, nb, sb, bi, au, pt, pd, ni, fe, co, cr, mg, ce, ag, na, K, ca, Y, ta, hf, ba, V, sr, te, la, or a combination thereof.

5. The anode-solid electrolyte proton assembly according to claim 3, wherein the compound of formula 3 is SnO ₂ 、CuO、SiO ₂ 、GeO、Al ₂ O ₃ ZnO, or combinations thereof.

6. The negative electrode according to claim 1-a solid electrolyte proton assembly, wherein the first anode active material layer is: li in which x is 1.ltoreq.3 and y is 1.ltoreq.3 _x Sn _y And Li in which a is 1.ltoreq.a.ltoreq.3 and b is 1.ltoreq.b.ltoreq.4 _a N _b Is a mixture of (a) and (b); li in which x is 1.ltoreq.3 and y is 1.ltoreq.3 _x Sn _y Sn with a being 1-3 and b being 1-4 _a N _b And SnO ₂ Is a mixture of (a) and (b); li, cu in which x is 1.ltoreq.3 and y is 1.ltoreq.3 _x N _y And Li where x=3 and y=1 _x N _y Is a mixture of (a) and (b); li in which x is 1.ltoreq.3 and y is 1.ltoreq.3 _x Cu _y And Li in which a is 1.ltoreq.a.ltoreq.3 and b is 1.ltoreq.b.ltoreq.4 _a N _b Is a mixture of (a) and (b); li in which x is 1.ltoreq.3 and y is 1.ltoreq.3 _x Sn _y And Li in which a is 1.ltoreq.a.ltoreq.3 and b is 1.ltoreq.b.ltoreq.4 _a N _b Is a complex of (a) and (b); li in which x is 1.ltoreq.3 and y is 1.ltoreq.3 _x Sn _y Sn with a being 1-3 and b being 1-4 _a N _b And SnO ₂ Is a complex of (a) and (b); li, cu in which x is 1.ltoreq.3 and y is 1.ltoreq.3 _x N _y And Li where x=3 and y=1 _x N _y Is a complex of (a) and (b); li in which x is 1.ltoreq.3 and y is 1.ltoreq.3 _x Cu _y And Li in which a is 1.ltoreq.a.ltoreq.3 and b is 1.ltoreq.b.ltoreq.4 _a N _b Is a complex of (a) and (b); or a combination thereof.

7. The anode-solid electrolyte proton assembly according to claim 1, wherein the third metal material of the intermediate layer is a mixture of a compound of formula 4 and a compound of formula 5, a complex of a compound of formula 4 and a compound of formula 5, or a combination thereof:

4. The method is to

Li _a -M3 _b -O _c

Wherein in formula 4, M3 is the third metal and Al, zn, sn, si, ge, cu, in, ga, ti, zr, nb, sb, bi, au, pt, pd, ni, fe, co, cr, mg, ce, ag, na, K, ca, Y, ta, hf, ba, V, sr, te, la, or a combination thereof, and

5. The method is to

M3 _c O _d

Wherein in formula 5, M3 is the third metal and Al, zn, sn, si, ge, cu, in, ga, ti, zr, nb, sb, bi, au, pt, pd, ni, fe, co, cr, mg, ce, ag, na, K, ca, Y, ta, hf, ba, V, sr, te, la, or a combination thereof, and

8. The anode-solid electrolyte proton assembly according to claim 1, wherein the third metal material is: wherein 0 is<a≤9、0<b is less than or equal to 3 and 0<c is less than or equal to 7 Li _a -Sn _b -O _c And 0 therein<c is less than or equal to 3 and 0<Sn with d.ltoreq.4 _c O _d Is a complex of (a) and (b); wherein 0 is<a≤9、0<b is less than or equal to 3 and 0<c is less than or equal to 7 Li _a -Cu _b -O _c And 0 therein<c is less than or equal to 5 and 0<Cu with d less than or equal to 24 _c O _d Is a complex of (a) and (b); wherein 0 is<a≤9、0<b is less than or equal to 3 and 0<c is less than or equal to 7 Li _a -Sn _b -O _c And 0 therein<c is less than or equal to 3 and 0<Sn with d.ltoreq.4 _c O _d Is a mixture of (a) and (b); wherein 0 is<a≤9、0<b is less than or equal to 3 and 0<c is less than or equal to 7 Li _a -Cu _b -O _c And 0 therein<c is less than or equal to 5 and 0<Cu with d less than or equal to 24 _c O _d Is a mixture of (a) and (b); or a combination thereof.

9. The anode-solid electrolyte proton assembly as claimed in claim 1, wherein the thickness of the intermediate layer is in a range of 5 nm to 100 nm, and

Wherein the volume of the first anode active material layer after charging the all-solid secondary battery is 200% or less of the volume of the first anode active material layer after discharging.

10. The anode-solid electrolyte proton assembly according to claim 1, further comprising a second anode active material layer disposed between the anode current collector and the first anode active material layer, and wherein the second anode active material layer comprises a fourth metal material, and the fourth metal material is a fourth metal, a lithium and a lithium alloy of the fourth metal, or a combination thereof,

wherein the fourth metal is a group 2 to 15 element, lithium alloy, or a combination thereof, and wherein the fourth metal comprises lithium, silver, tin, indium, silicon, gallium, aluminum, titanium, zirconium, niobium, germanium, antimony, bismuth, zinc, gold, platinum, palladium, nickel, iron, cobalt, chromium, magnesium, cesium, lanthanum, tungsten, tellurium, lithium alloy, or a combination thereof,

wherein the lithium alloy comprises

Lithium and method for producing the same

Silver, tin, indium, silicon, gallium, aluminum, titanium, zirconium, niobium, germanium, antimony, bismuth, zinc, gold, platinum, palladium, nickel, iron, cobalt, chromium, magnesium, cesium, lanthanum, tungsten, tellurium, or combinations thereof.

11. The anode-solid electrolyte proton assembly according to claim 1, wherein four to five peaks are observed in a region of 393 electron volts to 405 electron volts in the plot of intensity versus binding energy when the first anode active material layer is analyzed by X-ray photoelectron spectroscopy.

12. An all-solid secondary battery comprising:

a positive electrode; and

the anode-solid electrolyte proton assembly as claimed in any one of claims 1 to 11, provided on the anode,

wherein the solid electrolyte is between the positive electrode and the negative electrode.

13. The all-solid secondary battery according to claim 12, wherein the solid electrolyte comprises an oxide solid electrolyte, a sulfide solid electrolyte, or a combination thereof.

14. The all-solid secondary battery according to claim 13, wherein the oxide solid electrolyte is: li (Li) _1+x+ _y Al _x Ti _2-x Si _y P _3-y O ₁₂ Wherein 0 is<x<2 and 0.ltoreq.y<3；Li ₃ PO ₄ ；Li _x Ti _y (PO ₄ ) ₃ Wherein 0 is<x<2 and 0<y<3；Li _x Al _y Ti _z (PO ₄ ) ₃ Wherein 0 is<x<2，0<y<1 and 0<z<3；Li _1+x+y (Al _p Ga _1-p ) _x (Ti _q Ge _1-q ) _2-x Si _y P _3-y O ₁₂ Wherein x is more than or equal to 0 and less than or equal to 1, y is more than or equal to 0 and less than or equal to 1, p is more than or equal to 0 and less than or equal to 1, and q is more than or equal to 0 and less than or equal to 1; li (Li) _x La _y TiO ₃ Wherein 0 is<x<2 and 0<y<3；Li ₂ O；LiOH；Li ₂ CO ₃ ；LiAlO ₂ ；Li ₂ O-Al ₂ O ₃ -SiO ₂ -P ₂ O ₅ -TiO ₂ -GeO ₂ ；Li _3+x La ₃ M ₂ O ₁₂ Wherein M is Te, nb, or Zr, and x is an integer of 1 to 10; or a combination thereof, or wherein the oxide solid electrolyte is a garnet-type solid electrolyte, and the garnet-type solid electrolyte comprises an oxide represented by formula 6:

6. The method is to

(Li _x M1 _y )(La _a1 M2 _a2 ) _3-δ (Zr _b1 M3 _b2 ) _2-ω O _12-z X _z

Wherein in formula 6, M1 is hydrogen, iron, gallium, aluminum, boron, beryllium, or a combination thereof,

m2 is barium, calcium, strontium, yttrium, bismuth, praseodymium, neodymium, actinium, samarium, gadolinium, or a combination thereof,

m3 is hafnium, tin, niobium, titanium, vanadium, chromium, manganese, cobalt, nickel, copper, molybdenum, tungsten, tantalum, magnesium, technetium, ruthenium, palladium, iridium, scandium, cadmium, indium, antimony, tellurium, thallium, platinum, silicon, aluminum, or a combination thereof,

x is more than or equal to 3 and less than or equal to 8, y is more than or equal to 0 and less than or equal to 2, delta is more than or equal to 0.2 and less than or equal to 0.2, omega is more than or equal to 0.2 and less than or equal to 0 and less than or equal to 0.2, z is more than or equal to 2,

a1+a2=1, 0< a1.ltoreq.1, and 0.ltoreq.a2 <1,

b1+b2=1, 0< b1.ltoreq.1, and 0.ltoreq.b2 <1, and

x is a monovalent anion, a divalent anion, a trivalent anion, or a combination thereof, or wherein the oxide solid electrolyte is an oxide represented by formula 7:

7. The method of the invention

Li _3+x La ₃ Zr _2-a M _a O ₁₂

Wherein in formula 7, M is Al, ga, in, si, ge, sn, sb, bi, sc, Y, ti, hf, V, nb, ta, W, or a combination thereof, and

x is an integer of 1 to 10, and 0.ltoreq.a<2, and wherein the sulfide solid electrolyte is Li ₂ S-P ₂ S ₅ ；Li ₂ S-P ₂ S ₅ -LiX, wherein X is halogen; li (Li) ₂ S-P ₂ S ₅ -Li ₂ O；Li ₂ S-P ₂ S ₅ -Li ₂ O-LiI；Li ₂ S-SiS ₂ ；Li ₂ S-SiS ₂ -LiI；Li ₂ S-SiS ₂ -LiBr；Li ₂ S-SiS ₂ -LiCl；Li ₂ S-SiS ₂ -B ₂ S ₃ -LiI；Li ₂ S-SiS ₂ -P ₂ S ₅ -LiI；Li ₂ S-B ₂ S ₃ ；Li ₂ S-P ₂ S ₅ -Z _m S _n Wherein m and n are positive integers and Z is one of Ge, zn, or Ga; li (Li) ₂ S-GeS ₂ ；Li ₂ S-SiS ₂ -Li ₃ PO ₄ ；Li ₂ S-SiS ₂ -Li _p MO _q Wherein p and q are positive integers and M is one of P, si, ge, B, al, ga, or In; li (Li) _7- _x PS _6-x Cl _x Wherein 0 is<x<2；Li _7-x PS _6-x Br _x Wherein 0 is<x<2；Li _7-x PS _6-x I _x Wherein 0 is<x<2; or a combination thereof.

15. The all-solid secondary battery according to claim 12, wherein the anode current collector, the intermediate layer, the first anode active material layer, and a region between the anode current collector, the intermediate layer, and the first anode active material layer are lithium-free metal regions that do not contain lithium metal in an initial state or a post-discharge state of the all-solid secondary battery.

16. A method of preparing the all-solid secondary battery according to any one of claims 12 to 15, the method comprising:

providing the positive electrode;

disposing the solid electrolyte on the positive electrode;

disposing the intermediate layer on a first surface of the solid electrolyte opposite to a second surface of the solid electrolyte on which the positive electrode is disposed;

disposing the first anode active material layer on the intermediate layer and opposite to the solid electrolyte; and

the negative electrode current collector is disposed on the first negative electrode active material layer opposite to the intermediate layer to prepare the all-solid secondary battery.

17. The method of claim 16, wherein disposing the intermediate layer and the first anode active material layer comprises:

Depositing the first metal on the solid electrolyte in a nitrogen atmosphere to form a first layer comprising a first metal nitride layer; and

the first layer is brought into contact with lithium,

charging the all-solid secondary battery to supply lithium to the first layer,

heat treating the first layer, or a combination thereof,

18. The method of claim 16, wherein disposing the intermediate layer and the first anode active material layer comprises:

disposing the first metal on the solid electrolyte in an oxygen atmosphere to form a second layer including a first metal oxide layer and form the intermediate layer therefrom; and

the first metal is deposited on the second layer in a nitrogen atmosphere to form a first layer including the first metal nitride layer and form the first anode active material layer therefrom.

19. The method of claim 16, further comprising charging the all-solid secondary battery to form an alloy from the second metal and lithium in the first anode active material layer.