All-solid-state batteries with high energy density and stable operation

Abstract

This invention discloses a negative electrode-free all-solid-state battery that has high energy density and can operate stably.

Description

Technical Field

[0001] This invention relates to a novel negative electrode-free all-solid-state battery with high energy density and stable operation. Background Technology

[0002] Rechargeable batteries are used not only in small electronic devices such as mobile phones and laptops, but also in large transportation vehicles such as hybrid and electric vehicles. Therefore, there is a need to develop rechargeable batteries with higher stability and energy density.

[0003] Conventional secondary batteries are mostly constructed using organic solvents (organic liquid electrolytes), which limits their ability to improve stability and energy density.

[0004] Meanwhile, all-solid-state batteries that use inorganic solid electrolytes instead of organic solvents have recently attracted great attention, as they can be manufactured in a safer and simpler way.

[0005] However, a problem with all-solid-state batteries is that their energy density and power output performance are not as good as those of conventional lithium-ion batteries using liquid electrolytes. To address these issues, in-depth research is underway to improve the electrodes of all-solid-state batteries.

[0006] In particular, the negative electrode used in all-solid-state batteries is primarily formed from graphite. In this case, to ensure ionic conductivity, an excessive amount of solid electrolyte with a high specific gravity is added along with the graphite, resulting in a very low energy density per unit weight compared to lithium-ion batteries. Moreover, there are technological limitations in terms of price competitiveness and large-scale implementation when using lithium metal as the negative electrode.

[0007] Currently, in-depth research is being conducted on all-solid-state batteries with high energy density, one of which is the negative electrode-free all-solid-state battery. A negative electrode-free all-solid-state battery is one in which lithium is deposited on the negative electrode current collector, rather than using negative electrode active materials such as graphite or lithium metal.

[0008] Theoretically, all-solid-state batteries without negative electrodes can achieve high energy density, but uneven lithium deposition may lead to short circuits and increased irreversible reactions may cause battery performance to degrade. Summary of the Invention

[0009] In a preferred embodiment, a negative electrode-free all-solid-state battery with high energy density and stable operation is provided.

[0010] As used herein, the term "negative-electrode all-solid-state battery" refers to an all-solid-state battery that lacks a counter electrode assembly, i.e., a negative electrode, that has a compatible, parallel, and / or structurally similar appearance to the positive electrode. Conversely, a negative-electrode all-solid-state battery may include functional components that function similarly or equivalently as a conventional negative electrode. In some embodiments, a negative electrode current collector layer may serve as the counter electrode for the positive electrode in a negative-electrode all-solid-state battery, without including a negative electrode layer (e.g., lacking a negative electrode active material layer or a lithium layer) and forming a structure that is mismatched or asymmetrical with the positive electrode.

[0011] The purpose of this invention is not limited to the above-described objectives, and will be clearly understood from the following description, and can be achieved by the means and combinations thereof described in the claims.

[0012] In one aspect, an all-solid-state battery is provided, comprising: a negative electrode current collector layer; a porous layer disposed on the negative electrode current collector layer and having a porous structure comprising fibrous material; an electrolyte layer disposed on the porous layer; and a composite positive electrode layer disposed on the electrolyte layer, wherein at least a portion of the surface of the fibrous material is coated with a solid electrolyte.

[0013] Preferably, the fibrous materials are interconnected in three dimensions, for example, forming a mesh structure.

[0014] As used herein, "porous structure" refers to a porous material formed into a shape and including a variety of shapes, such as pores (e.g., circular or non-circular), holes, cavities (e.g., microcavities), labyrinths, channels, etc., whether uniformly or irregularly formed. Exemplary porous structures may include pores (e.g., closed or open pores) within a predetermined size range from submicron to micron, measured by the maximum diameter of the pores.

[0015] The fibrous material may suitably include one or more of the group consisting of carbon nanofibers, carbon nanotubes and vapor-grown carbon fibers, or other suitable materials.

[0016] Solid electrolytes can appropriately have a thickness of about 0.1 μm to 20 μm.

[0017] Solid electrolytes may suitably include sulfide solid electrolytes.

[0018] The porous layer can appropriately have a thickness of about 100 μm to 500 μm.

[0019] Porous layers can appropriately have a porosity of about 10% to 80%.

[0020] The porous layer may include: a first region extending from one surface of the negative electrode current collector layer to a predetermined depth; and a second region, which is the remainder of the layer other than the first region.

[0021] In an all-solid-state battery, the amount of solid electrolyte applied to the first region can be less than the amount of solid electrolyte applied to the second region.

[0022] In all-solid-state batteries, the lithium-ion conductivity of the solid electrolyte in the first region can be greater than that of the solid electrolyte in the second region.

[0023] In all-solid-state batteries, the electronic conductivity of the fiber material in the first region can be greater than that of the fiber material in the second region.

[0024] The first region may include metal particles that form an alloy with lithium.

[0025] The metal particles may include one or more selected from the group consisting of lithium (Li), indium (In), gold (Au), bismuth (Bi), zinc (Zn), aluminum (Al), iron (Fe), tin (Sn), and titanium (Ti).

[0026] This article also provides information on vehicles that include the all-solid-state batteries described herein.

[0027] According to various embodiments of the present invention, since the battery can be manufactured in the form of a thin film compared to conventional all-solid-state batteries, all-solid-state batteries with significantly improved energy density can be obtained.

[0028] Furthermore, since lithium is stably deposited in the porous layer, the formation of lithium dendrites and / or unreacted lithium can be suppressed, thus enabling all-solid-state batteries to operate stably.

[0029] The effects of the present invention are not limited to those described above, and should be understood to include all effects that can be reasonably expected from the following description.

[0030] Other aspects of the invention are disclosed below. Attached Figure Description

[0031] Figure 1 An exemplary all-solid-state battery according to an exemplary embodiment of the present invention is shown;

[0032] Figure 2 An exemplary internal pore structure of an exemplary porous layer of an exemplary all-solid-state battery according to an exemplary embodiment of the present invention is shown;

[0033] Figure 3 This is a reference diagram illustrating an exemplary porous layer of an exemplary all-solid-state battery according to an exemplary embodiment of the present invention;

[0034] Figure 4 This is a reference diagram illustrating an exemplary porous layer of an exemplary all-solid-state battery according to an exemplary embodiment of the present invention;

[0035] Figure 5Aand Figure 5B The results of analysis using an optical microscope of an exemplary porous layer according to an exemplary embodiment of the present invention and Comparative Example 1 are shown; and

[0036] Figure 6 The durability evaluation results of exemplary all-solid-state batteries according to exemplary embodiments of the present invention and comparative examples 1 and 2 are shown. Detailed Implementation

[0037] The above and other objects, features, and advantages of the present invention will become clearer from the following preferred embodiments, taken in conjunction with the accompanying drawings. However, the invention is not limited to the embodiments disclosed herein and can be modified into different forms. These embodiments are provided to thoroughly explain the invention and fully convey the spirit of the invention to those skilled in the art.

[0038] Throughout the accompanying drawings, the same reference numerals will refer to the same or similar elements. For clarity of the invention, the dimensions of the structures are described as larger than their actual dimensions. It should be understood that although terms such as "first," "second," etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, an element referred to below as "first" may be called "second" without departing from the scope of the invention. Similarly, a "second" element may also be called "first." As used herein, the singular forms are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0039] It will be further understood that, when used in this specification, the terms "comprising," "including," "having," etc., specify the presence of the stated features, integers, steps, operations, elements, components, or combinations thereof, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof. Furthermore, it will be understood that when an element such as a layer, film, region, or sheet is referred to as being "on" another element, it may be directly on top of the other element, or there may be intermediate elements between them. Similarly, when an element such as a layer, film, region, or sheet is referred to as being "below" another element, it may be directly below the other element, or there may be intermediate elements between them.

[0040] Unless otherwise stated, all figures, values ​​and / or representations indicating the quantities of components, reaction conditions, polymer compositions and mixtures used herein should be considered approximate and include various uncertainties that affect the measurement results substantially occurring at the time of obtaining these values, and therefore should be understood to be modified by the term “about” in all cases.

[0041] Unless otherwise specified or clearly indicated from the context, as used herein, the term “approximately” should be understood as falling within the normal tolerance range in this field, such as within 2 standard deviations of the mean. “Approximately” can be understood as within 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, 0.5%, 0.1%, 0.05%, or 0.01% of the stated value. Unless otherwise clearly indicated from the context, all numerical values ​​provided herein are modified by the term “approximately”.

[0042] Furthermore, when a numerical range is disclosed in this specification, the range is continuous and includes all values ​​from the minimum to the maximum of the range, unless otherwise stated. Additionally, when the range contains integer values, it includes all integers from the minimum to the maximum value, unless otherwise stated. For example, the range “5 to 10” should be understood to include any subranges such as 6 to 10, 7 to 10, 6 to 9, 7 to 9, etc., and individual values ​​of 5, 6, 7, 8, 9, and 10, and will also be understood to include any values ​​between valid integers within the range, such as 5.5, 6.5, 7.5, 5.5 to 8.5, 6.5 to 9, etc. Similarly, for example, the range “10% to 30%” will be understood to include subranges such as 10% to 15%, 12% to 18%, 20% to 30%, etc., and all integers including 10%, 11%, 12%, 13%, up to 30%, and should also be understood to include any value between valid integers within the range, such as 10.5%, 15.5%, 25.5%, etc.

[0043] It is understood that the terms "vehicle" or "of a vehicle" or other similar terms as used herein include motor vehicles in general, such as passenger vehicles including SUVs, buses, trucks, and various commercial vehicles, watercraft including various boats and vessels, and aircraft, and include hybrid vehicles, electric vehicles, plug-in hybrid electric vehicles, hydrogen-powered vehicles, and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). As mentioned herein, a hybrid vehicle is a vehicle with two or more power sources, such as a vehicle that combines gasoline and electric power.

[0044] Figure 1 An exemplary all-solid-state battery according to an exemplary embodiment of the present invention is shown.

[0045] Figure 2 The internal pore structure of an exemplary porous layer of an exemplary all-solid-state battery according to an exemplary embodiment of the present invention is shown.

[0046] like Figure 1 and Figure 2As shown, the all-solid-state battery 1 includes: a negative electrode current collector layer 10; a porous layer 20 disposed on the negative electrode current collector layer 10 and having a porous structure, the porous structure including three-dimensionally interconnected fibrous materials 21; an electrolyte layer 30 disposed on the porous layer 20; and a composite positive electrode layer 40 disposed on the electrolyte layer 30.

[0047] like Figure 2 As shown, at least a portion of the surface of the fiber material 21 may be coated with a solid electrolyte 23.

[0048] The negative current collector layer 10 can be a sheet-like or planar substrate.

[0049] The negative electrode current collector layer 10 may be a metal thin film comprising a metal composition selected from the group consisting of copper (Cu), nickel (Ni), and combinations thereof. In particular, the negative electrode current collector layer 10 may be a high-density metal thin film with a porosity of less than about 1%.

[0050] The thickness of the negative electrode current collector layer 10 can be from about 1 μm to 20 μm, particularly from about 5 μm to 15 μm.

[0051] The porous layer 20 is a layer that includes pores P, which serve as spaces for storing lithium deposited during charging of the all-solid-state battery 1, and the pores P can be formed by a mesh structure in which fibrous materials 21 are interconnected in three dimensions.

[0052] The fiber material 21 is configured to provide pathways for electrons to move within the porous layer 20.

[0053] The fiber material 21 may include one or more selected from the group consisting of carbon nanofibers, carbon nanotubes and vapor-grown carbon fibers.

[0054] There are no particular restrictions on the diameter, length, etc. of the fiber material 21, and any fiber material can be used, as long as the fiber material 21 is as described above. Figure 2 The interconnected elements form a network, as shown.

[0055] At least a portion of the surface of the fiber material 21 may be coated with a solid electrolyte 23.

[0056] The solid electrolyte 23 is configured to provide pathways for lithium ions to move within the porous layer 20.

[0057] The solid electrolyte 23 can be applied to a thickness of 0.1 μm to 20 μm. When its thickness is less than about 0.1 μm, its ability to transport lithium ions may decrease. On the other hand, when its thickness is greater than about 20 μm, problems related to electron movement or insufficient pores in lithium ion deposition may occur.

[0058] Solid electrolyte 23 may include sulfide solid electrolytes. There are no specific limitations on sulfide solid electrolytes, but they may include Li₂S-P₂S₅, Li₂S-P₂S₅-LiI, Li₂S-P₂S₅-LiCl, Li₂S-P₂S₅-LiBr, Li₂S-P₂S₅-Li₂O, Li₂S-P₂S₅-Li₂O-LiI, Li₂S-SiS₂, Li₂S-SiS₂-LiI, Li₂S-SiS₂-LiBr, Li₂S-SiS₂-LiCl, Li₂S-SiS₂-B₂S₃-LiI, Li₂S-SiS₂-P₂S₅-LiI, Li₂S-B₂S₃, and Li₂S-P₂S₅-Z. m S n (where m and n are positive numbers, and Z is any one of Ge, Zn, and Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li x MO y (where x and y are positive numbers, and M is any one of P, Si, Ge, B, Al, Ga, and In), Li 10 GeP2S 12 wait.

[0059] Furthermore, sulfide solid electrolytes can be amorphous or crystalline solid electrolytes. In particular, when a sulfide solid electrolyte is a crystalline solid electrolyte, it can have a cubic or argyrodite crystal structure.

[0060] There are no particular limitations on the lithium-ion conductivity of solid electrolyte 23; for example, it can be 1 × 10⁻⁶. -4 S / cm or greater.

[0061] Furthermore, there are no particular limitations on the diameter D50 of the solid electrolyte 23, which can be, for example, approximately 0.1 μm to 10 μm. Here, the diameter of the solid electrolyte 23 refers to the diameter of the solid electrolyte in its powder state before coating, rather than the diameter of the solid electrolyte in its coated state on the fiber material 21.

[0062] The porous layer 20 can have a thickness of about 100 μm to 500 μm and a porosity of about 10% to 80%. When the thickness and porosity of the porous layer 20 fall within the above range, the energy density of the all-solid-state battery can be greatly increased.

[0063] Figure 3 This is a reference diagram illustrating a porous layer 20 according to various exemplary embodiments of the present invention. Referring to this diagram, the porous layer 20 may include a first region 20A extending from one surface of the negative electrode current collector layer 10 to a predetermined depth and a second region 20B comprising the remainder other than the first region 20A.

[0064] There is no particular limitation on the depth of the first region 20A, which can be approximately 10% to 50% of the total thickness of the porous layer 20.

[0065] The porous layer 20 is characterized in that the amount of solid electrolyte 23 applied to the first region 20A is less than the amount of solid electrolyte 23 applied to the second region 20B.

[0066] The second region 20B can be coated with a high concentration of solid electrolyte 23, thereby suppressing the movement of electrons in the second region 20B. Therefore, lithium ions and electrons can combine more actively with each other in the first region 20A, where electrons are relatively more mobile. Consequently, lithium is deposited from the pores near the negative electrode current collector layer 10. Because lithium is in close contact with the negative electrode current collector layer 10, it can be more easily converted into lithium ions when the all-solid-state battery 1 discharges, thereby improving charging and discharging efficiency.

[0067] Alternatively, the porous layer 20 is characterized in that the lithium-ion conductivity of the solid electrolyte in the first region 20A is greater than that of the solid electrolyte in the second region 20B.

[0068] There are no particular limitations on the method for changing the lithium-ion conductivity of the solid electrolyte included in the first region 20A and the second region 20B. For example, different types of solid electrolytes or solid electrolytes with different crystallinity can be used in the respective regions.

[0069] Preferably, the lithium-ion conductivity in the first region 20A in contact with the negative electrode current collector layer 10 can be increased. Therefore, in the first region 20A where lithium ions move relatively quickly, lithium ions and electrons can combine more actively. Consequently, lithium is deposited from the pores near the negative electrode current collector layer 10. Because lithium is in close contact with the negative electrode current collector layer 10, lithium can be more easily converted into lithium ions when the all-solid-state battery 1 discharges, thereby improving charging and discharging efficiency.

[0070] Furthermore, the porous layer 20 is characterized in that the electronic conductivity of the fiber material 21 in the first region 20A is greater than that of the fiber material 21 in the second region 20B.

[0071] Preferably, as described above, this facilitates the relative movement of electrons in the first region 20A. Therefore, lithium ions and electrons can combine more actively in the first region 20A. Consequently, lithium can be deposited from the pores near the negative electrode current collector layer 10. Because lithium is in close contact with the negative electrode current collector layer 10, it can be more easily converted into lithium ions when the all-solid-state battery 1 discharges, thereby improving charging and discharging efficiency.

[0072] Figure 4This is a reference diagram illustrating an exemplary porous layer 20 according to an exemplary embodiment of the present invention. Specifically, Figure 4 The internal hole structure of the first region 20A is shown.

[0073] Referring to the figure, the first region 20A may include metal particles 25 that form an alloy with lithium.

[0074] The metal particles 25 are configured as seed crystals for lithium ions to migrate into the porous layer 20 during charging of the all-solid-state battery 1. For example, when the all-solid-state battery 1 is charged, lithium ions can grow primarily around the metal particles 25 as lithium.

[0075] The metal particles 25 may include one or more selected from the group consisting of lithium (Li), indium (In), gold (Au), bismuth (Bi), zinc (Zn), aluminum (Al), iron (Fe), tin (Sn) and titanium (Ti).

[0076] The electrolyte layer 30 is inserted between the porous layer 20 and the composite cathode layer 40, allowing lithium ions to move between the two layers.

[0077] The solid electrolyte layer 30 may comprise an oxide solid electrolyte or a sulfide solid electrolyte. Preferably, a sulfide solid electrolyte with high lithium-ion conductivity is used. There are no particular limitations on the sulfide solid electrolyte, and it may include Li₂S-P₂S₅, Li₂S-P₂S₅-LiI, Li₂S-P₂S₅-LiCl, Li₂S-P₂S₅-LiBr, Li₂S-P₂S₅-Li₂O, Li₂S-P₂S₅-Li₂O-LiI, Li₂S-SiS₂, Li₂S-SiS₂-LiI, Li₂S-SiS₂-LiBr, Li₂S-SiS₂-LiCl, Li₂S-SiS₂-B₂S₃-LiI, Li₂S-SiS₂-P₂S₅-LiI, Li₂S-B₂S₃, and Li₂S-P₂S₅-Z. m S n (where m and n are positive numbers, and Z is any one of Ge, Zn, and Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li x MO y (where x and y are positive numbers, and M is any one of P, Si, Ge, B, Al, Ga, and In), Li 10 GeP2S 12 wait.

[0078] The composite positive electrode layer 40 may include a positive electrode active material layer 41 disposed on the electrolyte layer 30 and a positive electrode current collector layer 42 disposed on the positive electrode active material layer 41.

[0079] The positive electrode active material layer 41 may include a positive electrode active material, a solid electrolyte, a conductive material, a binder, etc.

[0080] The positive electrode active material may be an oxide active material or a sulfide active material.

[0081] The oxide active material may be: a rock salt layer type active material, such as LiCoO2, LiMnO2, LiNiO2, LiVO2, Li 1+x Ni 1 / 3 Co 1 / 3 Mn 1 / 3 O2, etc.; a spinel type active material, such as LiMn2O4, Li(Ni 0.5 Mn 1.5 )O4, etc.; an inverse spinel type active material, such as LiNiVO4, LiCoVO4, etc.; an olivine type active material, such as LiFePO4, LiMnPO4, LiCoPO4, LiNiPO4, etc.; a silicon-containing active material, such as Li2FeSiO4, Li2MnSiO4, etc.; a rock salt layer type active material in which a part of the transition metal is replaced by a different metal, for example, LiNi 0.8 Co (0.2-x) Al x O2(0 < x < 0.2); a spinel type active material in which a part of the transition metal is replaced by a different metal, such as Li 1+x Mn 2-x-y M y O4 (M is Al, Mg, Co, Fe, Ni and Zn, 0 < x + y < 2), etc.; or lithium titanate, such as Li4Ti5O 12 etc.

[0082] The sulfide active material may suitably include Chevrel phase Cu2Mo6S8 (copper chevrel), iron sulfide, cobalt sulfide, nickel sulfide, etc.

[0083] The solid electrolyte may be an oxide solid electrolyte or a sulfide solid electrolyte. Here, a sulfide solid electrolyte with high lithium ion conductivity is preferably used. The sulfide solid electrolyte is not particularly limited and may include Li2S-P2S5, Li2S-P2S5-LiI, Li2S-P2S5-LiCl, Li2S-P2S5-LiBr, Li2S-P2S5-Li2O, Li2S-P2S5-Li2O-LiI, Li2S-SiS2, Li2S-SiS2-LiI, Li2S-SiS2-LiBr, Li2S-SiS2-LiCl, Li2S-SiS2-B2S3-LiI, Li2S-SiS2-P2S5-LiI, Li2S-B2S3, Li2S-P2S5-Zm S n (where m and n are positive numbers, and Z is any one of Ge, Zn, and Ga), Li2S-GeS2, Li2S-SiS2-Li3PO4, Li2S-SiS2-Li x MO y (where x and y are positive numbers, and M is any one of P, Si, Ge, B, Al, Ga, and In), Li 10 GeP2S 12 The solid electrolyte may be the same as or different from the solid electrolyte in the solid electrolyte layer 30.

[0084] Conductive materials may appropriately include carbon black, conductive graphite, ethylene black, graphene, etc.

[0085] The adhesive may suitably include BR (butadiene rubber), NBR (nitrile rubber), HNBR (hydrogenated nitrile rubber), PVDF (polyvinylidene fluoride), PTFE (polytetrafluoroethylene), CMC (carboxymethyl cellulose), etc., and may be the same as or different from the adhesive in the porous layer 20.

[0086] The positive current collector layer 42 can be aluminum foil, etc.

[0087] The present invention will be better understood through the following embodiments, which are merely illustrative and do not constitute a limitation on the scope of the invention.

[0088] Example

[0089] First, a porous layer is prepared. A layer in which carbon nanofibers, serving as the fibrous material, are interconnected in three dimensions is prepared. This layer has a thickness of approximately 350 μm and a porosity of approximately 80%. The layer is impregnated with a slurry containing a solid electrolyte to provide a porous layer in which at least a portion of the surface of the fibrous material is coated with the solid electrolyte. Here, Li6PS5Cl is used as the solid electrolyte and is added to a non-polar solvent along with butadiene rubber as a binder to prepare the aforementioned slurry. Based on observations using an optical microscope, the thickness of the solid electrolyte coating is approximately 10 μm. Furthermore, the porosity of the porous layer is approximately 60%.

[0090] A porous layer and a negative electrode current collector layer are bonded together, and an electrolyte layer and a composite positive electrode layer are laminated on the porous layer to fabricate an all-solid-state battery. The negative electrode current collector layer, electrolyte layer, and composite positive electrode layer used are commonly used in the art to which this invention pertains.

[0091] Comparative Example 1

[0092] The all-solid-state battery was manufactured in the same manner as in the examples, except that a solid electrolyte was not coated onto the fibrous material when forming the porous layer.

[0093] Comparative Example 2

[0094] The all-solid-state battery was manufactured in the same manner as in the examples, except that a porous layer was obtained by adding carbon nanotubes and vapor-grown carbon fibers as additives, instead of using a solid electrolyte to coat the fiber material.

[0095] Test Example 1 - Analysis Results of Optical Microscope (OM)

[0096] Figure 5A and 5B The results of optical microscopy analysis of the porous layers of Examples and Comparative Example 1 are shown. Specifically, unlike Comparative Example 1, the porous layer structure of Examples involves coating the surface of the fibrous material with a solid electrolyte.

[0097] Test Example 2 – Durability Evaluation of All-Solid-State Batteries

[0098] The durability of the all-solid-state batteries of Examples 1 and 2 was evaluated at temperatures of 0.1°C and 70°C. The results were... Figure 6 As shown in the figure. Specifically, compared to the initial capacity, the all-solid-state battery in the examples retains 90% or more of its capacity up to about 16 cycles, while in Comparative Example 1, the capacity retention rate is significantly reduced after 3 cycles, and in Comparative Example 2, it does not exceed 11 cycles.

[0099] As previously described, the present invention has been described in detail with reference to test examples and exemplary embodiments. However, the scope of the present invention is not limited to the test examples and embodiments described above, and various modifications and improvements of the invention using the basic concepts of the invention as defined in the appended claims are also incorporated into the scope of the invention.

Claims

1. An all-solid-state battery, comprising: Negative electrode current collector layer; A porous layer formed of three-dimensionally interconnected fibrous material is disposed on the negative electrode current collector layer and has a porous structure; An electrolyte layer disposed on the porous layer; and A composite positive electrode layer is disposed on the electrolyte layer. In this embodiment, at least a portion of the surface of the fiber material is coated with a solid electrolyte. The porous layer includes: a first region extending from one surface of the negative electrode current collector layer to a predetermined depth; and a second region, which is the remaining portion excluding the first region. The first region and the second region share a single mesh structure framework formed by interconnected fibrous materials in three dimensions. The electronic conductivity of the fiber material in the first region is greater than that of the fiber material in the second region. The amount of solid electrolyte applied to the first region is less than the amount of solid electrolyte applied to the second region, and The first region includes metal particles that form an alloy with lithium.

2. The all-solid battery according to claim 1, wherein The fiber material includes one or more selected from the group consisting of carbon nanofibers, carbon nanotubes, and vapor-grown carbon fibers.

3. The all-solid battery according to claim 1, wherein The thickness of the solid electrolyte is from 0.1 μm to 20 μm.

4. The all-solid battery according to claim 1, wherein The solid electrolyte includes sulfide solid electrolytes.

5. The all-solid battery according to claim 1, wherein The thickness of the porous layer is 100 μm to 500 μm.

6. The all-solid battery according to claim 1, wherein The porosity of the porous layer is 10% to 80%.

7. The all-solid battery according to claim 1, wherein The lithium-ion conductivity of the solid electrolyte in the first region is greater than that of the solid electrolyte in the second region.

8. The all-solid battery according to claim 1, wherein The metal particles include one or more selected from the group consisting of lithium (Li), indium (In), gold (Au), bismuth (Bi), zinc (Zn), aluminum (Al), iron (Fe), tin (Sn), and titanium (Ti).

9. A vehicle comprising the all-solid-state battery according to claim 1.

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