KR20230133684A - The structure for all solid secondary battery and solid secondary battery including the same - Google Patents

Abstract

anode layer; and a solid electrolyte layer disposed on the positive electrode layer, wherein the positive electrode layer includes a positive electrode current collector and a positive electrode active material layer disposed on one or both sides of the positive electrode current collector, and the solid electrolyte layer is oriented in a plane direction. The maximum cross-sectional area among the cross-sectional areas that can be obtained when cutting is larger than the area of the maximum cross-sectional area that can be obtained when cutting the positive electrode active material layer in the plane direction, and the solid electrolyte layer covers the positive electrode active material layer, and a structure for an all-solid-state secondary battery. An all-solid-state secondary battery including the structure for an all-solid-state secondary battery is provided.

Description

Structure for an all-solid secondary battery and an all-solid secondary battery including the same {THE STRUCTURE FOR ALL SOLID SECONDARY BATTERY AND SOLID SECONDARY BATTERY INCLUDING THE SAME}

It relates to a structure for an all-solid-state secondary battery and an all-solid-state secondary battery including the same.

Recently, in response to industrial demands, the development of batteries with high energy density and safety has been actively conducted. For example, lithium-ion batteries are being put into practical use not only in the fields of information-related devices and communication devices, but also in the automobile field. In the automotive field, safety is especially important because it involves life.

Lithium-ion batteries currently on the market use electrolytes containing flammable organic solvents, so there is a risk of overheating and fire in the event of a short circuit. In response to this, an all-solid secondary battery using a solid electrolyte instead of an electrolyte has been proposed.

By not using flammable organic solvents, all-solid-state secondary batteries can greatly reduce the possibility of fire or explosion even if a short circuit occurs. Therefore, these all-solid-state secondary batteries can greatly increase safety compared to lithium-ion batteries that use electrolytes.

One aspect is to provide a structure for an all-solid-state secondary battery and an all-solid-state secondary battery including the same.

According to one embodiment,

anode layer; And a solid electrolyte layer disposed on the anode layer,

The positive electrode layer includes a positive electrode current collector and a positive electrode active material layer disposed on one or both sides of the positive electrode current collector,

The area of the largest cross-sectional area among the cross-sectional areas that can be derived when cutting the solid electrolyte layer in the plane direction is larger than the area of the maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the positive electrode active material layer in the plane direction,

A structure for an all-solid secondary battery is provided, wherein the solid electrolyte layer covers the positive electrode active material layer.

According to another embodiment,

A positive electrode layer including a positive electrode current collector and a positive electrode active material layer; A negative electrode current collector and a non-negative coating layer disposed on the negative electrode current collector; And a solid electrolyte layer disposed between the positive electrode active material layer and the negative electrode coating layer,

The area of the largest cross-sectional area among the cross-sectional areas that can be derived when cutting the solid electrolyte layer in the plane direction is larger than the area of the maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the positive electrode active material layer in the plane direction,

An all-solid-state secondary battery is provided in which the solid electrolyte layer covers the positive electrode active material layer.

According to one aspect, the structure for an all-solid-state secondary battery has a maximum cross-sectional area among cross-sectional areas that can be obtained when cutting the solid electrolyte layer in the plane direction, which is greater than the area of the maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the positive electrode active material layer in the plane direction. large, the movement area of lithium ions may increase.

Accordingly, the all-solid-state secondary battery including the structure for an all-solid-state secondary battery can grow lithium metal uniformly, effectively preventing exposure of the negative electrode current collector due to non-uniform growth of lithium metal. In addition, the occurrence of cracks and sudden drop of the all-solid-state secondary battery due to non-uniform growth of lithium metal can be effectively prevented.

Figure 1 is a cross-sectional view of a structure for an all-solid secondary battery according to an embodiment.
Figure 2 is a cross-sectional view of an all-solid-state secondary battery according to an embodiment.
Figure 3 is a cross-sectional view of an all-solid-state secondary battery on which a lithium metal layer is formed according to an embodiment.
Figure 4 is a cross-sectional view of an all-solid-state secondary battery according to a comparative example.
Figure 5 is a cross-sectional view of an all-solid-state secondary battery with a lithium metal layer formed according to a comparative example.

anode layer; and a solid electrolyte layer disposed on the positive electrode layer, wherein the positive electrode layer includes a positive electrode current collector and a positive electrode active material layer disposed on one or both sides of the positive electrode current collector,

The area of the maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the solid electrolyte layer in the plane direction is larger than the area of the maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the positive electrode active material layer in the plane direction, and the solid electrolyte layer is the cathode active material layer. A structure for an all-solid-state secondary battery may be provided.

The structure for an all-solid-state secondary battery has a maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the solid electrolyte layer in the plane direction, which is larger than the maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the positive electrode active material layer in the plane direction, so that the lithium ions The movement area can be increased. Accordingly, lithium ions can be moved uniformly.

The present inventive concept described below can be subjected to various transformations and can have various embodiments, and specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit this creative idea to a specific embodiment, and should be understood to include all transformations, equivalents, or substitutes included in the technical scope of this creative idea.

The terms used below are only used to describe specific embodiments and are not intended to limit the creative idea. Singular expressions include plural expressions unless the context clearly dictates otherwise. Hereinafter, terms such as "comprise" or "have" are intended to indicate the presence of features, numbers, steps, operations, components, parts, ingredients, materials, or combinations thereof described in the specification, but are intended to indicate the presence of one or more of the It should be understood that this does not exclude in advance the presence or addition of other features, numbers, steps, operations, components, parts, components, materials, or combinations thereof. “/” used below may be interpreted as “and” or “or” depending on the situation.

In order to clearly express various layers and areas in the drawing, the thickness is enlarged or reduced. Throughout the specification, similar parts are given the same reference numerals. Throughout the specification, when a part such as a layer, membrane, region, plate, etc. is said to be “on” or “on” another part, this includes not only the case where it is directly on top of the other part, but also the case where there is another part in between. . Throughout the specification, terms such as first and second may be used to describe various components, but the components should not be limited by the terms. Terms are used only to distinguish one component from another. In this specification and drawings, components having substantially the same functional configuration are given the same reference numerals and redundant description is omitted.

Hereinafter, all-solid-state secondary batteries according to example embodiments will be described in more detail.

In this specification, the term "non-cathode coating layer for an all-solid-state battery" refers to a coating layer formed on the top of the current collector in a non-cathode all-solid-state battery that does not have a negative electrode active material layer during battery assembly. When an all-solid-state battery with a non-cathode coating layer is charged, lithium is absorbed into the non-cathode coating layer, and after the charging capacity of the non-cathode coating layer is exceeded, a lithium metal layer is formed between the anode current collector and the non-cathode coating layer.

[Structure for all-solid-state secondary battery (10)]

Figure 1 is a cross-sectional view of a structure for an all-solid secondary battery according to an embodiment.

Referring to Figure 1, the structure 10 for an all-solid-state secondary battery includes an anode layer 100; and a solid electrolyte layer 200 disposed on the positive electrode layer 100, wherein the positive electrode layer 100 is disposed on one or both sides of the positive electrode current collector 110 and the positive electrode current collector 110. It may include a positive electrode active material layer 120.

For example, in the all-solid-state secondary battery structure 10, the maximum cross-sectional area (B) among the cross-sectional areas that can be derived when cutting the solid electrolyte layer 200 in the plane direction (X) is the cathode active material layer 120. The solid electrolyte layer 200 may cover the positive electrode active material layer 120, which is larger than the maximum cross-sectional area (A) among the cross-sectional areas that can be obtained when cutting in the plane direction (X).

In this case, lithium (Li) ions can be uniformly diffused from the positive electrode active material layer 120 to the solid electrolyte layer 200. Accordingly, when the structure 10 for an all-solid-state secondary battery is applied to an all-solid-state secondary battery, which will be described later, as the lithium ions are uniformly diffused, a lithium metal layer is evenly formed on the negative electrode layer, which will be described later, within the all-solid-state secondary battery. Crack occurrence and plummeting can be effectively prevented.

For example, the solid electrolyte layer 200 may be formed to cover the positive electrode active material layer 120, so that at least a portion of the solid electrolyte layer 200 may be formed on the positive electrode current collector 110.

For example, the solid electrolyte layer 200 is formed to cover the positive electrode active material layer 120, so that at least a portion of the solid electrolyte layer 200 is in direct contact with the positive electrode current collector 110. can do.

For example, the solid electrolyte layer 200 may be formed on at least one of the top surface of the positive electrode active material layer 120 and the side surface of the positive electrode active material layer 120.

For example, the solid electrolyte layer 200 may be in direct contact with at least one of the top surface of the positive electrode active material layer 120 and the side surface of the positive electrode active material layer 120.

According to one embodiment, the solid electrolyte layer 200 may cover at least a portion of the positive electrode active material layer 120.

According to another embodiment, the solid electrolyte layer 200 may completely cover the positive electrode active material layer 120.

According to one embodiment, the solid electrolyte layer 200 completely covers the positive electrode active material layer 120, meaning that the solid electrolyte layer 200 covers the upper surface of the positive electrode active material layer 120 and the positive electrode active material. This may mean that the layer 120 is formed to cover all sides.

For example, the solid electrolyte layer 200 covers the positive electrode active material layer 120, meaning that the solid electrolyte layer 200 formed on the positive electrode active material layer 120 is larger than the positive electrode active material layer 120. This may mean that it is formed over a large area. In this case, the solid electrolyte layer 200 may be formed on two or more surfaces of the positive electrode active material layer 120 that are not in contact with the positive electrode current collector 110.

According to another embodiment, the fact that the solid electrolyte layer 200 completely covers the positive electrode active material layer 120 means that the solid electrolyte layer 200 is formed on the upper surface of the positive electrode active material layer 120 and the positive electrode active material. All sides of the layer 120 may be covered, and at least a portion of the solid electrolyte layer 200 may be formed on the positive electrode current collector 110 . In this case, the positive electrode current collector 110 and the solid electrolyte layer 200 may be directly contacted.

For example, the surface direction (X) may mean a direction perpendicular to the thickness direction (Y) of the anode layer 100 and the thickness direction (Y) of the solid electrolyte layer 200.

For example, the maximum cross-sectional area (B) among the cross-sectional areas that can be derived when cutting the solid electrolyte layer 200 in the plane direction (X) can be formed by cutting the solid electrolyte layer 200 in the plane direction (X). It may refer to the widest cross-sectional area among a plurality of cross-sectional shapes.

According to one embodiment, the area (C) of the maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the positive electrode current collector 110 in the plane direction is the maximum cross-sectional area among the cross-sectional areas that can be derived when the solid electrolyte layer 200 is cut in the plane direction. It may be less than or equal to the area (B) of .

[Anode layer (100)]

[Anode layer (100): Anode active material layer (120)]

The positive electrode active material layer 120 may include, for example, a positive electrode active material and a solid electrolyte. For example, the positive electrode active material may include lithium transition metal oxide.

For example, the solid electrolyte included in the positive electrode layer 100 may be the same as or different from the solid electrolyte included in the solid electrolyte layer 200, which will be described later.

According to one embodiment, the positive electrode active material may be a positive electrode active material capable of reversibly absorbing and desorbing lithium ions. For example, the positive electrode active material includes lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), and lithium nickel cobalt manganese oxide ( NCM), lithium transition metal oxides such as lithium manganate, lithium iron phosphate, nickel sulfide, copper sulfide, lithium sulfide, iron oxide, vanadium oxide, or any combination thereof may include.

According to another embodiment, the positive electrode active material may include lithium transition metal oxide. For example, the lithium transition metal oxide includes lithium cobalt oxide (LCO), lithium nickel oxide, lithium nickel cobalt oxide, lithium nickel cobalt aluminum oxide (NCA), and lithium nickel cobalt manganese. It may include oxide (NCM), lithium manganate, lithium iron phosphate, or any combination thereof.

According to one embodiment, the lithium transition metal oxide is Li _a A _1-b B _b D ₂ (wherein 0.90 ≤ a ≤ 1 and 0 ≤ b ≤ 0.5); Li _a E _1-b B _b O _2-c D _c (in the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); LiE _2-b B _b O _4-c D _c (wherein 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05); Li _a Ni _1-bc Co _b B _c D _α (wherein 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α ≤ 2); Li _a Ni _1-bc Co _b B _c O _2-α F _α (wherein 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α <2); Li _a Ni _1-bc Co _b B _c O _2-α F ₂ (wherein 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α <2); Li _a Ni _1-bc Mn _b B _c D _α (wherein 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α ≤ 2); Li _a Ni _1-bc Mn _b B _c O _2-α F _α (wherein 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α <2); Li _a Ni _1-bc Mn _b B _c O _2-α F ₂ (wherein 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.5, 0 ≤ c ≤ 0.05, 0 < α <2); Li _a Ni _b E _c G _d O ₂ (In the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0.001 ≤ d ≤ 0.1); Li _a Ni _b Co _c Mn _d GeO ₂ (In the above formula, 0.90 ≤ a ≤ 1, 0 ≤ b ≤ 0.9, 0 ≤ c ≤ 0.5, 0 ≤ d ≤0.5, 0.001 ≤ e ≤ 0.1); Li _a NiG _b O ₂ (in the above formula, 0.90 ≤ a ≤ 1, 0.001 ≤ b ≤ 0.1); Li _a CoG _b O ₂ (in the above formula, 0.90 ≤ a ≤ 1, 0.001 ≤ b ≤ 0.1); Li _a MnG _b O ₂ (in the above formula, 0.90 ≤ a ≤ 1, 0.001 ≤ b ≤ 0.1); Li _a Mn ₂ G _b O ₄ (in the above formula, 0.90 ≤ a ≤ 1, 0.001 ≤ b ≤ 0.1); QO ₂ ; QS ₂ ; LiQS ₂ ; V ₂ O ₅ ; LiV ₂ O ₅ ; LiIO ₂ ; LiNiVO ₄ ; Li _(3-f) J ₂ (PO ₄ ) ₃ (0 ≤ f ≤ 2); Li _(3-f) Fe ₂ (PO ₄ ) ₃ (0 ≤ f ≤ 2); It may be an oxide represented by any one of the chemical formulas of LiFePO ₄ .

Among the lithium transition metal oxides, A is Ni, Co, Mn, or a combination thereof; B is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; E is Co, Mn, or a combination thereof; F is F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; Q is Ti, Mo, Mn, or a combination thereof; I is Cr, V, Fe, Sc, Y, or a combination thereof; J may be V, Cr, Mn, Co, Ni, Cu, or a combination thereof.

For example, the lithium transition metal oxide may further include a coating layer formed on the surface. For example, the lithium transition metal oxide may simultaneously include an oxide with a coating layer formed on its surface and an oxide without a coating layer.

According to one embodiment, the coating layer may include a coating element compound of the oxide, hydroxide, oxyhydroxide of the coating element, oxycarbonate of the coating element, or hydroxycarbonate of the coating element.

According to one embodiment, the oxide forming the coating layer may be amorphous or crystalline. For example, the coating element included in the coating layer may include Mg, Al, Co, K, Na, Ca, Si, Ti, V, Sn, Ge, Ga, B, As, Zr, or any combination thereof. You can.

For example, the method of forming the coating layer may be selected within a range that does not adversely affect the physical properties of the positive electrode active material. For example, the method of forming the coating layer may include spray coating, dipping, etc.

For example, the positive electrode active material may include a lithium salt of the transition metal oxide having a layered rock salt type structure among the lithium transition metal oxides described above. “Layered rock salt type structure” is, for example, a cubic rock salt type structure in which oxygen atomic layers and metal atomic layers are alternately and regularly arranged in the <111> direction, whereby each atomic layer forms a two-dimensional plane. It may be a structure that forms a .

“Cubic rock salt type structure” refers to a sodium chloride type (NaCl type) structure, which is a type of crystal structure, and the face centered cubic lattice (fcc) formed by cations and anions, respectively, forms the function of a unit lattice. It can represent a structure arranged offset by 1/2 of the ridge. The lithium transition metal oxide having this layered rock salt structure is, for example, LiNi _x Co _y Al _z O ₂ (NCA) or LiNi _x Co _y Mn _z O ₂ (NCM) (0 < x < 1, 0 < y It may be a ternary lithium transition metal oxide such as < 1, 0 < z < 1, 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 energy density and thermal stability of the all-solid secondary battery including the all-solid secondary battery structure 10 will be further improved. You can.

For example, the positive electrode active material may further include a coating layer as described above. According to one embodiment, the coating layer may include Li ₂ O-ZrO ₂ (LZO).

For example, when the cathode active material contains nickel (Ni) as a ternary lithium transition metal oxide such as NCA or NCM, the capacity density of the all-solid-state secondary battery, which will be described later, is increased, and metal elution from the cathode active material in the charged state is reduced. It can be. Accordingly, the cycle characteristics of the all-solid-state secondary battery, which will be described later, can be improved.

According to one embodiment, the shape of the positive electrode active material may be a particle shape such as a sphere or an elliptical sphere.

[Anode layer: solid electrolyte]

According to one embodiment, the positive electrode active material layer 120 may include a solid electrolyte.

For example, the solid electrolyte included in the positive electrode layer 100 may be the same as or different from the solid electrolyte included in the solid electrolyte layer 200. For further details on the solid electrolyte, refer to the solid electrolyte layer 200 described later.

The solid electrolyte included in the positive electrode active material layer 120 may have a D50 average particle diameter smaller than that of the solid electrolyte included in the solid electrolyte layer 200. For example, the D50 average particle diameter of the solid electrolyte included in the positive electrode active material layer 120 is 90% or less, 80% or less, 70% or less, 60% or less of the D50 average particle diameter of the solid electrolyte included in the solid electrolyte layer 30. % or less, 50% or less, 40% or less, 30% or less, or 20% or less.

For example, the D50 average particle diameter may be the median particle diameter (D50). The median particle diameter (D50) may mean the size of a particle corresponding to 50% of the cumulative volume calculated from the side of the particle having a small particle size in the particle size distribution measured, for example, by laser diffraction.

[Anode layer: binder]

According to one embodiment, the positive electrode active material layer 120 may further include a binder. For example, the binder may include styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, or any combination thereof.

[Anode layer: conductive material]

According to one embodiment, the positive electrode active material layer 120 may further include a conductive material. For example, the conductive material may include graphite, carbon black, acetylene black, Ketjen black, carbon fiber, metal powder, or any combination thereof.

[Anode layer: Other additives]

According to one embodiment, the positive electrode active material layer 120 may further include additives such as filler, coating agent, dispersant, and ion conductivity auxiliary agent in addition to the positive electrode active material, solid electrolyte, binder, and conductive material described above. .

For example, fillers, coating agents, dispersants, ion conductive auxiliaries, etc. that the positive electrode active material layer 120 may contain may be known materials that are generally used in electrodes of all-solid-state secondary batteries.

[Anode layer: Anode current collector]

According to one embodiment, the positive electrode current collector 110 is made of indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), and nickel (Ni). , it may include a plate or foil made of zinc (Zn), aluminum (Al), germanium (Ge), lithium (Li), or an alloy thereof.

According to one embodiment, the thickness of the positive electrode current collector 11 may be, for example, 1 um to 100 um, 1 um to 50 um, 5 um to 25 um, or 10 um to 20 um.

[Solid electrolyte layer]

[Solid electrolyte layer: solid electrolyte]

According to one embodiment, the solid electrolyte layer 200 may include a solid electrolyte.

According to one embodiment, the solid electrolyte is a sulfide-based solid electrolyte. For example, the sulfide-based solid electrolyte is Li ₂ SP ₂ S ₅ , Li ₂ SP ₂ S ₅ -LiX (X is a halogen element), Li ₂ SP ₂ S ₅ -Li ₂ O, Li ₂ SP 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 SB ₂ S ₃ , Li ₂ SP ₂ S ₅ -Z _m S _n (m, n are positive numbers, Z are Ge, Zn or one of Ga), Li ₂ S-GeS ₂ , Li ₂ S-SiS ₂ -Li ₃ PO ₄ , Li ₂ S-SiS ₂ -Li _p MO _q (p, q are positive numbers, M is P, Si , Ge, B, Al, Ga In), Li _7-x PS _6-x Cl _x (0≤x≤2, Li _7-x PS _6-x Br _x , 0≤x≤2) and Li _{7 -x} PS _6-x I _x (0≤x≤2) or any combination thereof.

According to another embodiment, the sulfide-based solid electrolyte can be manufactured by processing starting materials such as Li ₂ S and P ₂ S ₅ by melting quenching or mechanical milling. Additionally, after this treatment, heat treatment may be performed.

According to one embodiment, the solid electrolyte may be amorphous, crystalline, or any combination thereof. For example, the solid electrolyte may include sulfur (S), phosphorus (P), and lithium (Li) as constituent elements among the sulfide-based solid electrolyte materials described above.

For example, the sulfide-based solid electrolyte material forming the solid electrolyte may include Li ₂ SP ₂ S ₅ . When using a sulfide-based solid electrolyte material that forms the solid electrolyte containing Li ₂ SP ₂ S ₅ , the mixing molar ratio of Li ₂ S and P ₂ S ₅ is Li ₂ S: P ₂ S ₅ = 50: 50. It could be 90:10.

For example, the sulfide-based solid electrolyte may include an argyrodite type solid electrolyte represented by the following formula (1):

<Formula 1>

_Li ^{+ 12} _{- nx} A ^{n +}

where A is P, As, Ge, Ga, Sb, Si, Sn, Al, In, Ti, V, Nb or Ta, X is S, Se or Te, and Y is Cl, Br, I, F , CN, OCN, SCN, or N ₃ , 1≤n≤5, 0≤x≤2.

The sulfide-based solid electrolyte is, for example, Li _7-x PS _6-x Cl _x , 0≤x≤2, Li _7-x PS _6-x Br _x , 0≤x≤2, and Li _7-x PS ₆ It may be an argyrodite-type compound containing one or more selected from _-x I _x and 0≤x≤2. For example, the sulfide-based solid electrolyte may be an argyrodite-type compound containing one or more selected from Li ₆ PS ₅ Cl, Li ₆ PS ₅ Br, and Li ₆ PS ₅ I.

The density of the argyrodite-type solid electrolyte may be 1.5 to 2.0 g/cc. Argyrodite-type solid electrolyte has a density of 1.5 g/cc or more, which reduces the internal resistance of the all-solid secondary battery and effectively suppresses penetration of the solid electrolyte layer by Li. can do.

[Solid electrolyte layer: binder]

According to one embodiment, the solid electrolyte layer 200 may include a binder.

For example, the binder included in the solid electrolyte layer 200 may be, for example, styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, or It may include any combination of these.

For example, the binder included in the solid electrolyte layer 200 may be the same as or different from the binder included in the positive electrode active material layer 120 described above and the negative electrode layer 300 described later.

The binder content contained in the solid electrolyte layer 200 is 0 to 10 wt%, 0 to 5 wt%, 0 to 3 wt%, 0 to 1 wt%, 0 to 0.5 wt%, or It may be 0 to 0.1 wt%.

[All-solid-state secondary battery]

Figure 2 is a cross-sectional view of an all-solid-state secondary battery according to an embodiment.

Referring to FIG. 2, the all-solid-state secondary battery 20 includes a positive electrode layer 100 including a positive electrode current collector 110 and a positive electrode active material layer 120; a negative electrode layer 300 including a negative electrode current collector 320 and a non-negative coating layer disposed on the negative electrode current collector; And a solid electrolyte layer 200 disposed between the anode layer 100 and the cathode layer 300, and the largest cross-sectional area among the cross-sectional areas that can be obtained when the solid electrolyte layer 200 is cut in the plane direction (X). The area of (B) is larger than the area of the maximum cross-sectional area (A) among the cross-sectional areas that can be derived when cutting the positive electrode active material layer 120 in the plane direction (X), and the solid electrolyte layer 200 is formed by the positive electrode active material layer 120. ) can be covered.

For a description of the anode layer 100 and the solid electrolyte layer 200, refer to the above description.

According to one embodiment, the maximum cross-sectional area (A) among the cross-sectional areas that can be derived when cutting the positive electrode active material layer 120 in the plane direction (X) is the cross-sectional area that can be derived when the negative electrode current collector 320 is cut in the plane direction. It may be smaller than the area of the maximum cross-sectional area (D). In this case, defects due to misalignment of the anode layer 100, solid electrolyte layer 200, and cathode layer 300 are reduced during the manufacturing process of the all-solid-state secondary battery 20, and the all-solid-state secondary battery ( 20) productivity can be improved.

According to one embodiment, the area of the maximum cross-sectional area (B) among the cross-sectional areas that can be derived when cutting the solid electrolyte layer 200 in the plane direction (X) is the area when cutting the negative electrode current collector 320 in the plane direction (X). Among the cross-sectional areas that can be derived, it may be greater than or equal to the area of the maximum cross-sectional area (D). In this case, defects due to misalignment of the anode layer 100, solid electrolyte layer 200, and cathode layer 300 are reduced during the manufacturing process of the all-solid-state secondary battery 20, and the all-solid-state secondary battery ( 20) productivity can be improved.

According to one embodiment, the area of the maximum cross-sectional area (C) among the cross-sectional areas that can be derived when cutting the positive electrode current collector 110 in the plane direction (X) is the area of the maximum cross-sectional area (C) when cutting the negative electrode current collector 320 in the plane direction (X). Among the cross-sectional areas that can be derived, it may be larger than the maximum cross-sectional area (D). In this case, defects due to misalignment of the anode layer 100, solid electrolyte layer 200, and cathode layer 300 are reduced during the manufacturing process of the all-solid-state secondary battery 20, and the all-solid-state secondary battery ( 20) productivity can be improved.

According to one embodiment, among the cross-sectional areas that can be derived when cutting the solid electrolyte layer 200 in the plane direction (X), the cross-sectional area of the area adjacent to the anode layer 100 is greater than the cross-sectional area of the area adjacent to the cathode layer 300. It can be small.

[Cathode layer]

Referring to FIG. 2, the negative electrode 300 may include a negative electrode current collector 320 and a non-negative electrode coating layer 310.

According to one embodiment, the negative electrode current collector 320 may be made of a material that does not react with lithium, that is, does not form any alloy or compound.

For example, the material constituting the negative electrode current collector 320 includes copper (Cu), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), or these. Any combination may be used. For example, the negative electrode current collector 310 may be formed in a plate shape or a thin shape.

For example, a thin film may be formed on the surface of the negative electrode current collector 320. The thin film may contain an element that can form an alloy with lithium. Elements that can form alloys with lithium may include, for example, gold, silver, zinc, tin, indium, silicon, aluminum, bismuth, or any combination thereof. For example, the thin film can further flatten the precipitation form of the metal layer, which will be described later, and thus the characteristics of the all-solid-state secondary battery 20 can be further improved.

According to one embodiment, the thin film may be disposed between the anode current collector 320 and the non-cathode coating layer 310. The thickness of the thin film may be 1 nm to 500 nm.

According to one embodiment, the thin film may be formed on the negative electrode current collector 320 by vacuum deposition, sputtering, plating, etc.

According to one embodiment, the non-cathode coating layer 310 includes a cathode active material and a binder and can be stabilized on the anode current collector.

According to one embodiment, the non-cathode coating layer 310 may include a cathode active material that forms an alloy or compound with lithium.

According to one embodiment, the negative electrode active material is amorphous carbon, gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), and bismuth (Bi). ), tin (Sn), zinc (Zn), or any combination thereof.

For example, the amorphous carbon includes carbon black (CB), acetylene black (AB), furnace black (FB), ketjen black (KB), etc. It may include graphene or any combination thereof.

According to another embodiment, the non-cathode coating layer 310 contains only amorphous carbon as a cathode active material or one or more metals selected from the group consisting of gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, and zinc. It may also be included.

According to another embodiment, the non-cathode coating layer 310 includes amorphous carbon; and at least one metal selected from the group consisting of gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, and zinc.

According to one embodiment, the weight ratio of the amorphous carbon and the metal may be, for example, 10:1 to 1:2. For example, when the negative electrode active material includes the amorphous carbon and the metal to satisfy the above range, the characteristics of the all-solid-state secondary battery 20 may be further improved.

According to another embodiment, the weight ratio of the amorphous carbon and the metal may be, for example, 3:1 to 1:1.

According to one embodiment, when the negative electrode active material includes one or more metals from gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, and zinc, the particle size (e.g., average particle diameter (D50) of the negative electrode active material is )) may be about 4㎛ or less. For example, when the particle size of the anode active material satisfies the above range, the characteristics of the all-solid-state secondary battery 20 may be further improved. According to one embodiment, the particle size of the anode active material may be about 10 nm or more.

Here, the particle size of the negative electrode active material can be, for example, the median diameter (so-called D50) measured using a laser particle size distribution meter.

According to one embodiment, the negative electrode active material may have the form of particles, and the average particle diameter of the negative electrode active material may be about 1 to 3 μm.

According to one embodiment, the negative electrode active material may include a mixture of first particles formed of amorphous carbon and second particles formed of metal or semiconductor. The metal or semiconductor may include, for example, gold, platinum, palladium, silicon, silver, aluminum, bismuth, tin, zinc, etc. Here, the content of the second particles may be about 8 to 60% by weight or about 10 to 50% by weight based on the total weight of the mixture.

According to one embodiment, when the anode active material contains silicon, the silicon may become amorphous after initial charge and discharge.

According to one embodiment, the negative electrode active material may include a mixture of amorphous carbon and silicon (Si) or a mixture of amorphous carbon and silver (Ag).

The negative electrode active material may include a mixture of first particles formed of amorphous carbon and second particles formed of metal or semiconductor, and the content of the second particles is 100 parts by weight of the total weight of the mixture. It may be 8 to 60 parts by weight, for example 10 to 70 parts by weight, for example 15 to 60 parts by weight.

According to one embodiment, the binder may include a conductive binder. For example, the conductive binder can stabilize the non-cathode coating layer 310 on the anode current collector 320 and improve resistance characteristics.

According to one embodiment, the conductive binder may include a block copolymer containing a conductive domain and a non-conductive domain.

For example, the conductive domain of the block copolymer may be a region responsible for ionic conductivity and/or electronic conductivity of the block copolymer, and the non-conductive domain may be a region related to the mechanical properties of the block copolymer.

In the block copolymer according to one embodiment, the conductive domain is a polymer containing an ion-conducting repeating unit, a crosslinked network phase mixture of a polymer containing an ion-conducting repeating unit, and a polymer containing an electronically conducting repeating unit. Or it may include any combination thereof.

According to one embodiment, the polymer containing the ion conductive repeating unit is polyethylene oxide, polysilsesquioxane, poly(ethylene glycol)methyl ether methacrylate (POEM), polysiloxane, Polypropylene oxide, polymethyl methacrylate, polyethyl methacrylate, polydimethylsiloxane, polyacrylic acid, polymethacrylic acid, polymethyl acrylate, polyethyl acrylate, poly2-ethylhexyl acrylate, polybutyl methacrylate It may be one or more selected from the group consisting of polyester, poly2-ethylhexyl methacrylate, polydecyl acrylate, polyethylene vinyl acetate, polyimide, polyamine, polyamide, polyalkyl carbonate, polynitrile, and polyphosphazine.

According to one embodiment, among block copolymers in which the conductive domain includes a mixture of a polymer containing an ion-conducting repeating unit and a crosslinked network phase, the crosslinked network phase is formed by reaction of a compound containing a crosslinkable reactive group. As obtained, it includes products obtained by chemical bonding of crosslinkable reactive compounds. For example, the above chemical bond may mean a covalent bond. For example, a polymer containing an ion-conducting repeating unit and a cross-linked network phase may be physically bonded. Here, being physically bound may mean connected through a non-covalent bond.

According to one embodiment, the crosslinkable reactive group-containing compound may include one or more selected from the group consisting of a multifunctional polymerizable monomer having a crosslinkable reactive group, an inorganic particle having a crosslinkable reactive group, and an ionic liquid having a crosslinkable reactive group. For example, the crosslinked network phase may include a reaction product of the crosslinkable reactive group-containing compound described above.

According to one embodiment, the crosslinkable reactive group-containing compound may include one or more units selected from a lithium ion conductive unit and a hydrophilic unit. For example, when the crosslinkable reactive group-containing compound includes the unit, when preparing an electrolyte, the crosslinking reaction of the crosslinkable reactive group-containing compound proceeds in the ion conductive domain, resulting in a block copolymer having an ion conductive domain including a crosslinked network phase. and an electrolyte containing it can be formed.

According to one embodiment, the multifunctional polymerizable monomer having a crosslinkable reactive group is polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, ethoxylated trimethylolpropane triacrylate, and ethoxylated trimethylolpropane tri. Methacrylate, 1,4-butadane, 1,6-hexadiene, allyl acrylate, acrylated cinnamate, isoprene, butadiene, chloroprene, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 2-hydroxyethylene glycol (meth)acrylate , 2-hydroxypropylene glycol (meth)acrylate, acrylic acid, methacrylic acid, 2-(meth)acryloyloxy acetic acid, 3-(meth)acryloyloxy propionic acid, 4-(meth)acryloyloxy Butyric acid, itaconic acid, maleic acid, 2-isocyanatoethyl (meth)acrylate, 3-isocyanatopropyl (meth)acrylate, 4-isocyanatobutyl (meth)acrylate, (meth)acrylate ) Acrylamide, N-vinyl pyrrolidone, ethylene dimethacrylate, diethylene glycol methacrylate, triethylene glycol dimethacrylate, trimethylene propane trimethacrylate, trimethylene propane triacrylate, 1,3 -It may include one or more selected from butanediol methacrylate, 1,6-hexanediol dimethacrylate, and N-vinyl caprolactam.

According to one embodiment, the block copolymer in which the conductive domain includes a mixture of a polymer containing an ion conductive repeating unit and a crosslinked network phase includes i) a first block of polystyrene, and polyethylene glycol diacrylate. and a block copolymer containing a second block containing a reaction product selected from polyethylene glycol dimethacrylate and polyethylene oxide; ii) a block copolymer containing a first polystyrene block, a second block containing polyethylene oxide and a reaction product selected from polyethylene glycol diacrylate and polyethylene glycol dimethacrylate, and a third polystyrene block; Or it may include any combination thereof.

For example, polymers containing the electronically conductive repeating units include polyaniline (PANI) and polypyrrole. (polypyrrole, PPy), poly(3,4-ethylenedioxythiophene)PEDOT), poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate)(poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) ) (PEDOT: PSS).

For example, the non-conductive domain is a region responsible for mechanical properties in a block copolymer and has a structural domain, a rubbery domain, an olefin domain, and an organic-inorganic silicone structure. may include domains or any combination thereof.

In the block copolymer according to one embodiment, the structural domain contains a structural block including a plurality of structural repeating units, and the structural block may include a polymer including a structural repeating unit. Polymers containing the structural repeating unit include i) polystyrene, hydrogenated polystyrene, polymethacrylate, poly(methyl methacrylate), polyvinylpyridine, polyvinylcyclohexane, polyimide, polyamide, polyethylene, and polyisobutyl. lene, polybutylene, polypropylene, poly(4-methyl pentene-1), poly(butylene terephthalate), poly(isobutyl methacrylate), poly(ethylene terephthalate), polydimethylsiloxane, polyacrylic Nitrile, polyvinylcyclohexane, polymaleic acid, polymaleic anhydride, polymethacrylic acid, poly(tertbutyl vinyl ether), poly(cyclohexyl methacrylate), poly(cyclohexyl vinyl ether), poly(tertbutyl) It may be one or more selected from vinyl ether), polyvinylidene fluoride, and polydivinylbenzene, or ii) a copolymer containing two or more types of repeating units constituting the above-mentioned polymer.

According to one embodiment, the rubbery domain has excellent properties in all of strength, ductility, and elasticity, and may contain a rubbery block including a plurality of rubbery repeating units. For example, the rubber block may include one or more selected from the group consisting of polyisoprene, polybutadiene, polychloroprene, polyisobutylene, and polyurethane.

According to one embodiment, the block copolymer having the rubber-like domain is, for example, a block copolymer comprising a polystyrene first block and a polyisoprene second block, a polystyrene first block, a polyisoprene second block, and a polystyrene third block. A block copolymer containing a block, a block copolymer containing a polystyrene first block and a polybutadiene second block, or a block copolymer containing a polystyrene first block, a polybutadiene second block and a polystyrene third block, or these Any combination may be included.

According to one embodiment, the olefin-based domain is a non-conductive region and may contribute to mechanical properties such as tensile strength. For example, it contains an olefin-based block containing a plurality of olefin-based repeating units, and the olefin-based block may include a polymer containing an olefin-based repeating unit. For example, the polymer containing the olefinic repeating unit may include one or more selected from the group consisting of polyethylene, polybutylene, polyisobutylene, and polypropylene. For example, the block copolymer having the olefinic domain may include polyethylene oxide-polypropylene block copolymer, polyethylene oxide-polypropylene block copolymer, or any combination thereof.

According to one embodiment, the structural domain having the organic-inorganic silicon structure may be involved in the strength and mechanical properties of the non-cathode coating layer. For example, the organic-inorganic silicon structure may include a compound represented by Formula 1 below.

<Formula 1>

Si _n O _1.5n (R ¹ ) _a (R ² ) _b (R ³ ) _c

In Formula 1,

n=a+b+c, 6≤n≤20,

R ¹ , R ² , and R ³ are independently a hydrogen atom, an organic functional group, a silicon functional group, or a combination thereof.

According to one embodiment, the mixing weight ratio of the conductive domain and the non-conductive domain in the block copolymer is 1:99 to 99:1, for example, 10:90 to 90:10, for example, 20:85 to 15:80. , for example, may be 50 to 80 parts by weight.

According to one embodiment, when the block copolymer is a block copolymer containing an ion conductive domain and a structural domain, the content of the ion conductive domain may be 55 to 80 parts by weight based on 100 parts by weight of the total weight of the block copolymer. . For example, when the content of the ion conductive domain satisfies the above range, the lithium ion conductivity of the non-cathode coating layer is improved, and the movement characteristics of lithium ions to the positive electrode during discharge can be further improved.

For example, the block copolymer containing the ion conductive domain and the structural domain may be a block copolymer containing a first block of polystyrene and a second block containing polyethylene oxide; A block copolymer containing a first block of polystyrene, a second block containing polyethylene oxide, and a third block of polystyrene; A block copolymer containing a first block of polystyrene and a second block containing polysilsesquioxane; A block copolymer containing a first block of polystyrene, a second block containing polysilsesquioxane, and a third block of polystyrene; A block copolymer containing a first block of polystyrene and a second block containing poly(ethylene glycol)methyl ether methacrylate (POEM); A block copolymer containing a first block of polystyrene, a second block containing POEM, and a third block of polystyrene; A block copolymer containing a first block of polystyrene and a second block containing polysiloxane; A block copolymer containing a first block of polystyrene, a second block containing polysiloxane, and a third block of polystyrene; Or it may include any combination thereof.

According to one embodiment, the non-cathode coating layer 310 includes styrene butadiene rubber (SBR), polytetrafluoroethylene, polyvinylidene fluoride, and polyethylene in addition to the block copolymer described above as the conductive binder. It may further include a second binder such as (polyethylene). The content of the second binder may be 1 to 30 parts by weight based on 100 parts by weight of the total binder content.

According to one embodiment, the non-cathode coating layer 310 may be manufactured by applying and drying a negative electrode slurry in which the material constituting the non-cathode coating layer is dispersed on a negative electrode current collector.

According to one embodiment, when the negative electrode slurry is applied on the negative electrode current collector 320 using a screen printing method, clogging of the screen (for example, clogging by aggregates of the negative electrode active material) can be suppressed. For example, when using the conductive binder, dispersibility is improved compared to when using a non-conductive binder such as polyvinylidene fluoride, and the slurry production process time can be shortened.

According to one embodiment, the content of the binder may be 0.3 to 15 parts by weight, for example, 1 to 10 parts by weight, based on 100 parts by weight of the total weight of the negative electrode active material.

According to one embodiment, the thickness of the non-cathode coating layer 310 may be 1 μm to 20 μm.

For example, the thickness of the non-cathode coating layer 310 may be, for example, 1 to 10 ㎛. For example, when the thickness of the non-cathode coating layer 310 satisfies the above range, the performance of the all-solid-state battery can be further improved.

According to another embodiment, the non-cathode coating layer 310 may be appropriately mixed with additives used in general solid-state batteries, such as fillers, dispersants, and ion conductive agents.

According to another embodiment, the all-solid-state secondary battery 20 may further include a metal layer 315 disposed between the negative electrode current collector 320 and the non-negative electrode coating layer 310, and the metal layer 315 It may contain lithium or lithium alloy. The metal layer 315 may be formed between the negative electrode current collector and the non-negative coating layer before charging.

In this case, the metal layer 315 may be prepared in advance. For example, since the metal layer 315 functions as a lithium reservoir, the characteristics of the all-solid-state secondary battery 20 can be further improved. The thickness of the metal layer 315 may be about 1㎛ to 200㎛.

According to one embodiment, the negative electrode current collector 320, the non-negative electrode coating layer 310, and the area between them do not contain lithium (Li) in the initial or post-discharge state of the all-solid-state secondary battery 20. It may be a Li-free area.

Figure 3 is a cross-sectional view of an all-solid-state secondary battery in which a lithium metal layer is formed during charging of the all-solid-state secondary battery according to an embodiment.

Referring to Figures 2 and 3, when the all-solid-state secondary battery 20 according to this embodiment is charged, lithium is inserted into the non-cathode coating layer 310 at the beginning of charging. That is, the negative electrode active material can form an alloy or compound with lithium ions moving from the positive electrode 100. When charging exceeds the capacity of the non-cathode coating layer 310, lithium is precipitated on the back side of the non-cathode coating layer 310, that is, between the anode current collector 320 and the non-cathode coating layer 310, as shown in FIG. The metal layer 315 is formed by this lithium. The metal layer 315 may be mainly composed of lithium (i.e., metallic lithium). This phenomenon can occur by composing the negative electrode active material with a specific material, that is, a material that forms an alloy or compound with lithium.

During discharge, lithium in the non-cathode coating layer 310 and metal layer 315 is ionized and moves toward the anode 100. Therefore, lithium can be used as a negative electrode active material in the all-solid-state secondary battery 20. Additionally, since the non-cathode coating layer 310 covers the metal layer 315, it serves as a protective layer for the metal layer 315 and can suppress the precipitation growth of dendrites. This may serve to suppress short circuits and capacity deterioration of the all-solid-state secondary battery 20 and further improve the characteristics of the all-solid-state secondary battery 20.

Figure 4 is a cross-sectional view of an all-solid-state secondary battery according to a comparative example. Figure 5 is a cross-sectional view of an all-solid-state secondary battery with a lithium metal layer formed according to a comparative example.

For example, referring to FIG. 2, the all-solid-state secondary battery 20 according to an embodiment has the maximum cross-sectional area (B) among the cross-sectional areas that can be derived when cutting the solid electrolyte layer 200 in the plane direction (X). is larger than the maximum cross-sectional area (A) among the cross-sectional areas that can be derived when cutting the positive electrode active material layer 120 in the plane direction (X), and the solid electrolyte layer 200 can cover the positive electrode active material layer 120. .

Accordingly, referring to FIG. 3, the all-solid-state secondary battery 20 according to an embodiment has a maximum cross-sectional area (B) among the cross-sectional areas that can be derived when cutting the solid electrolyte layer 200 in the plane direction (X). Among the cross-sectional areas that can be derived when cutting the positive electrode active material layer 120 in the plane direction (X), the area is larger than the maximum cross-sectional area (A), and the solid electrolyte layer 200 covers the positive electrode active material layer 120, and the metal layer The area of the largest cross-sectional area among the cross-sectional areas that can be derived when cutting (315) in the plane direction ( ) may be equal to or larger than the maximum cross-sectional area that can be derived when cutting in the plane direction (X). Accordingly, in the process of charging the all-solid-state secondary battery 20, it is possible to effectively prevent the all-solid-state secondary battery from plummeting due to a short circuit between the non-cathode coating layer 310 and the negative electrode current collector 320.

For example, referring to FIG. 4, the all-solid-state secondary battery 30 according to a comparative example has a maximum cross-sectional area (B) among the cross-sectional areas that can be derived when cutting the solid electrolyte layer 200 in the plane direction (X). Among the cross-sectional areas that can be derived when cutting the positive electrode active material layer 120 in the plane direction (X), it is smaller than or equal to the maximum cross-sectional area (A), and the solid electrolyte layer 200 does not cover the positive electrode active material layer 120. It may not be possible.

Accordingly, referring to FIG. 5, the all-solid-state secondary battery 30 according to a comparative example has a maximum cross-sectional area (B) among the cross-sectional areas that can be derived when cutting the solid electrolyte layer 200 in the plane direction (X). Among the cross-sectional areas that can be derived when cutting the positive electrode active material layer 120 in the plane direction (X), it is smaller than or equal to the area of the maximum cross-sectional area (A), and the solid electrolyte layer 200 does not cover the positive electrode active material layer 120 , the area of the largest cross-sectional area among the cross-sectional areas that can be derived when cutting the metal layer 315 in the plane direction (X) is the maximum cross-sectional area among the cross-sectional areas that can be derived when the non-cathode coating layer 310 is cut in the plane direction ( Among the cross-sectional areas that can be derived when cutting the entire 320 in the plane direction (X), it may be smaller than the maximum cross-sectional area. Accordingly, in the process of charging the all-solid-state secondary battery 20, a short circuit may occur between the non-cathode coating layer 310 and the negative electrode current collector 320, which may cause the all-solid-state secondary battery to plummet.

The all-solid-state battery may be a lithium battery, for example, a lithium secondary battery. And the all-solid-state battery according to one embodiment may be an all-solid secondary.

As described above, the all-solid-state secondary battery according to this embodiment can be applied to various portable devices, vehicles, etc.

Although an exemplary embodiment has been described in detail with reference to the attached drawings, the creative idea is not limited to this example. It is obvious that anyone with ordinary knowledge in the technical field to which this creative idea belongs can derive various examples of changes or modifications within the scope of the technical idea described in the patent claims, and these are naturally within the technical scope of this creative idea. belongs to

10: Structure for all-solid-state secondary battery
20, 30: All-solid-state secondary battery
100: anode layer 110: anode current collector
120: positive electrode active material layer 200: solid electrolyte layer
300: cathode layer 310: non-cathode coating layer
320: negative electrode current collector 315: metal layer

Claims (20)

anode layer; And a solid electrolyte layer disposed on the anode layer,
The positive electrode layer includes a positive electrode current collector and a positive electrode active material layer disposed on one or both sides of the positive electrode current collector,
The area of the maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the solid electrolyte layer in the plane direction is larger than the area of the maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the positive electrode active material layer in the plane direction,
A structure for an all-solid-state secondary battery, wherein the solid electrolyte layer covers the positive electrode active material layer.
According to paragraph 1,
A structure for an all-solid secondary battery, wherein the solid electrolyte layer completely covers the positive electrode active material layer.
According to claim 1,
A structure for an all-solid-state secondary battery, wherein the maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the positive electrode current collector in the plane direction is smaller than or equal to the area of the maximum cross-sectional area among the cross-sectional areas that can be derived when the solid electrolyte layer is cut in the plane direction.

According to paragraph 1,
The positive electrode current collector is indium (In), copper (Cu), magnesium (Mg), stainless steel, titanium (Ti), iron (Fe), cobalt (Co), nickel (Ni), zinc (Zn), aluminum ( A structure for an all-solid-state secondary battery containing Al), germanium (Ge), lithium (Li), or alloys thereof.
The structure for an all-solid-state secondary battery according to claim 1, wherein the positive electrode active material layer includes lithium transition metal oxide.
According to paragraph 1,
The solid electrolyte layer is a structure for an all-solid secondary battery including a sulfide-based solid electrolyte.
A positive electrode layer including a positive electrode current collector and a positive electrode active material layer;
A negative electrode layer including a negative electrode current collector and a non-negative electrode coating layer disposed on the negative electrode current collector; and
It includes a solid electrolyte layer disposed between the anode layer and the cathode layer,
The area of the maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the solid electrolyte layer in the plane direction is larger than the area of the maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the positive electrode active material layer in the plane direction,
An all-solid-state secondary battery, wherein the solid electrolyte layer covers the positive electrode active material layer.
In clause 7,
An all-solid-state secondary battery in which the maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the positive electrode active material layer in the plane direction is smaller than the area of the maximum cross-sectional area among the cross-sectional areas that can be derived when the negative electrode current collector is cut in the plane direction.
In clause 7,
An all-solid-state secondary battery in which the maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the solid electrolyte layer in the plane direction is greater than or equal to the area of the maximum cross-sectional area among the cross-sectional areas that can be derived when the negative electrode current collector is cut in the plane direction.
In clause 7,
An all-solid-state secondary battery in which the maximum cross-sectional area among the cross-sectional areas that can be derived when cutting the positive electrode current collector in the plane direction is larger than the area of the maximum cross-sectional area among the cross-sectional areas that can be derived when the negative electrode current collector is cut in the plane direction.
In clause 7,
An all-solid-state secondary battery, wherein among the cross-sectional areas that can be derived when cutting the solid electrolyte layer in the plane direction, the cross-sectional area of the area adjacent to the positive electrode layer is smaller than the cross-sectional area of the area adjacent to the negative electrode layer.
In clause 7,
The non-cathode coating layer is an all-solid-state secondary battery including a cathode active material and a binder that forms an alloy or compound with lithium.
In clause 7,
The negative electrode active material is amorphous carbon, gold (Au), platinum (Pt), palladium (Pd), silicon (Si), silver (Ag), aluminum (Al), bismuth (Bi), and tin (Sn). , zinc (Zn), or any combination thereof.
In clause 7,
The negative electrode current collector, the non-negative electrode coating layer, and the area between them are Li-free areas that do not contain lithium (Li) in the initial or post-discharge state of the all-solid-state secondary battery.
In clause 7,
The negative electrode current collector, the non-negative electrode coating layer, and the area between them are areas containing lithium (Li) in the after-charge state of the all-solid-state secondary battery,
An all-solid-state secondary battery in which the area of the cross-sectional area that can be derived when cutting the region containing lithium (Li) in the plane direction is the same as the area of the cross-section that can be derived when the negative electrode current collector is cut in the plane direction.
In clause 7,
A thin film containing an element capable of forming an alloy with lithium is further provided on the negative electrode current collector,
The thin film is an all-solid-state secondary battery disposed between the negative electrode current collector and the negative electrode active material layer.
In clause 7,
An all-solid-state secondary battery further comprising a metal layer disposed between the negative electrode current collector and the non-negative electrode coating layer, wherein the metal layer includes lithium or a lithium alloy.
In clause 7,
After charging the all-solid-state battery, the non-cathode coating layer includes one or more selected from amorphous carbon, silver (Ag), silicon (Si), a lithium alloy thereof, and a composite thereof.
In clause 7,
An all-solid-state battery wherein the thickness of the non-cathode coating layer is 1㎛ to 20㎛.
In clause 7,
An all-solid-state battery further comprising a metal layer disposed between the cathode and the solid electrolyte, wherein the metal layer includes lithium or a lithium alloy.

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