KR102656439B1 - An all solid type battery and a method for manufacturing the same - Google Patents

Abstract

The all-solid-state battery according to the present invention can utilize battery cans used in existing batteries, so it can be used interchangeably with other types of batteries when manufacturing battery packs. In addition, since battery cans can be used as electrode assembly molds, batteries can be manufactured in a simple way. Since liquid electrolytes are not used, electrolyte leakage problems do not occur during battery manufacturing and use, which improves safety. There is.

Description

All-solid-state battery and method for manufacturing the same {An all solid type battery and a method for manufacturing the same}

The present invention relates to an all-solid-state battery and a method of manufacturing the same.

Depending on the shape of the battery case, secondary batteries are classified into cylindrical batteries and square batteries in which the electrode assembly is housed in a cylindrical or square metal can, and pouch-type batteries in which the electrode assembly is housed in a pouch-shaped case made of aluminum laminate sheet. .

In addition, the electrode assembly built into the battery case is a power generating element capable of charging and discharging composed of a laminated structure of anode/separator/cathode, and has a separator 12b between a long sheet-shaped anode 12a coated with an active material and a cathode 12c. ) is classified into a jelly-roll type structure wound with an interposed structure, and a stack type structure in which a plurality of anodes and cathodes of a predetermined size are sequentially stacked with a separator interposed therebetween. Among them, the jelly-roll type electrode assembly is the most widely manufactured because it is easy to manufacture and has the advantage of high energy density per weight. The jelly-roll type electrode assembly 12 is inserted into the battery case 13 and opened at the top of the case. The cap assembly 14 is installed and sealed to produce a cylindrical battery 10. Figure 1 schematically shows a cross section of such a cylindrical battery.

However, when charging and discharging a battery, the jelly-roll type electrode assembly tends to deform as it undergoes repeated expansion and contraction. In this process, stress is concentrated in the center, causing the electrode to penetrate the separator and contact the metal center pin 15, causing an internal short circuit. The organic solvent is decomposed due to heat generation due to the internal short circuit, generating gas, and the battery may rupture due to an increase in gas pressure within the battery. This increase in gas pressure inside the battery can also occur when an internal short circuit occurs due to an external shock.

Cylindrical secondary batteries are unit cells that can be connected in series or parallel to form large batteries, and can be manufactured into battery packs of the required capacity, shape, and size depending on the number of inputs and/or connection methods, making them industrially useful. However, if the above-mentioned problem occurs in only one unit cell of the battery pack, difficulties in electricity supply may occur. In other words, it is difficult to quickly detect a problem unit cell, and a situation may arise where the entire battery pack must be replaced. Accordingly, measures to improve the safety of unit batteries are required.

The purpose of the present invention is to propose a new type of all-solid-state battery for commercialization of all-solid-state batteries that do not require a liquid electrolyte. Other objects and advantages of the present invention may be understood by the following description. In addition, it will be readily apparent that the objects and advantages of the present invention can be realized by means or methods and combinations thereof described in the claims.

The present invention relates to an all-solid-state battery and a method of manufacturing the same. The first aspect of the present invention relates to the all-solid-state battery, wherein the battery includes a battery can made of a metal material and having an open top; And an electrode assembly inserted into the battery can,

The electrode assembly forms a layered structure by sequentially stacking a negative electrode layer, a solid electrolyte layer, and a positive electrode layer from the bottom of the battery can, and the negative electrode layer includes a negative electrode current collector and a negative electrode active material layer formed on one side of the current collector. The positive electrode layer includes a positive electrode current collector and a positive electrode active material layer formed on one surface of the current collector, and the negative electrode active material layer and the positive electrode active material layer face each other with the solid electrolyte layer interposed therebetween.

In a second aspect of the present invention, in the first aspect, the all-solid-state battery is sealed by installing a cap assembly on the open top.

A third aspect of the present invention is that, in the first or second aspect, the electrode assembly is inserted in such a way that the negative electrode layer, the solid electrolyte layer, and the positive electrode layer are buried in the battery can, so that the electrode assembly and the inner wall of the battery can are spaced apart from each other. It is designed so that this does not happen.

A fourth aspect of the present invention is that, in the third aspect, the inner wall of the battery can is covered with an insulating material.

A fifth aspect of the present invention is that, in any one of the first to fourth aspects, the solid electrolyte includes an inorganic solid electrolyte.

A sixth aspect of the present invention is that, in the fourth aspect, the inorganic solid electrolyte includes a sulfide-based solid electrolyte.

A seventh aspect of the present invention is that, in any one of the first to sixth aspects, when the height of the negative electrode active material layer is h1 and the height of the positive electrode active material layer is h3, h1 < h3.

Additionally, the present invention relates to a method of manufacturing an all-solid-state battery. The eighth aspect of the present invention relates to the above method, and includes the following steps (S1) to (S6), wherein the inner wall of the battery can is coated with an insulating material:

(S1) preparing a battery can made of metal and open at the top;

(S2) placing a negative electrode current collector at the bottom of the battery can so that it is in close contact with the bottom of the battery can;

(S3) forming a negative electrode active material layer on the upper surface of the negative electrode current collector to have a predetermined height h1;

(S4) forming a solid electrolyte layer to have a predetermined height h2 on the upper surface of the negative electrode active material layer;

(S5) forming a positive electrode active material layer to have a predetermined height h3 on the upper surface of the solid electrolyte layer; and

(S6) Placing a positive electrode current collector on the upper surface of the positive electrode active material layer.

The all-solid-state battery according to the present invention can utilize battery cans used in existing cylindrical batteries or square batteries, so it can be used interchangeably with other types of batteries when manufacturing battery packs. In addition, since battery cans can be used as electrode assembly molds, batteries can be manufactured in a simple way. Since liquid electrolytes are not used, electrolyte leakage problems do not occur during battery manufacturing and use, which improves safety. There is.

The drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to better understand the technical idea of the present invention together with the contents of the above-described invention, so the present invention is limited only to the matters described in such drawings. It is not interpreted as such. Meanwhile, the shape, size, scale, or ratio of elements in the drawings included in this specification may be exaggerated to emphasize a clearer description.
Figure 1 schematically shows the structure of the internal cross section of a battery manufactured according to the prior art.
Figure 2 schematically shows the structure of the internal cross section of the all-solid-state battery according to the present invention.
FIG. 3A schematically shows a current collector including needle-shaped protrusions, and FIG. 3B schematically shows a cross section of a battery including the current collector.
FIG. 4A schematically shows a current collector including branch-shaped protrusions, and FIG. 4B schematically shows a cross section of a battery including the current collector.
Figure 5 schematically shows a current collector including protrusions having a three-dimensional network structure.
Figure 6 shows a current collector in which the protruding portion and the base portion are separated.
Figure 7 schematically shows that, in a specific embodiment of the present invention, the surface of the inner wall of the battery can is covered with an insulating material.

Hereinafter, the present invention will be described in detail. Prior to this, the terms or words used in this specification and patent claims should not be construed as limited to their usual or dictionary meanings, and the inventor should appropriately define the concept of terms in order to explain his or her invention in the best way. It must be interpreted with meaning and concept consistent with the technical idea of the present invention based on the principle that it can be done. Therefore, the embodiments described in this specification and the configurations shown in the drawings are only one of the most preferred embodiments of the present invention, and do not represent the entire technical idea of the present invention, so they can be replaced at the time of filing the present application. It should be understood that various equivalents and variations may exist.

Throughout the specification of the present application, when it is said that a part “includes” a certain component, this means that it does not exclude other components but may further include other components, unless specifically stated to the contrary.

In addition, the terms "about", "substantially", etc. used throughout the specification of the present application are used as meanings at or close to the numerical value when manufacturing and material tolerances inherent in the mentioned meaning are presented, and to aid understanding of the present application. It is used to prevent unscrupulous infringers from unfairly exploiting disclosures in which precise or absolute figures are mentioned.

Throughout this specification, the description of “A and/or B” means “A or B or both.”

Certain terms used in the detailed description of the invention that follow are for convenience and not limitation. The words 'right', 'left', 'top' and 'bottom' indicate directions in the drawings to which reference is made. The words 'inwardly' and 'outwardly' indicate directions toward or away from the geometric center of the specified device, system and its members, respectively. 'Front', 'rear', 'upward', 'downward' and related words and phrases indicate positions and orientations in the drawings to which reference is made and should not be limiting. These terms include the words listed above, their derivatives and words of similar meaning.

The present invention relates to an all-solid-state battery. Figure 2 schematically shows a cross section of a battery 100 according to a specific embodiment of the present invention. With reference to this, the battery includes a battery can 130 made of a metal material and having an open top; and an electrode assembly inserted into the battery can, wherein the electrode assembly has a layered structure in which a cathode layer 160, a solid electrolyte layer 110, and an anode layer 170 are sequentially stacked from the bottom of the battery can. is forming. In addition, the negative electrode layer includes a negative electrode current collector 130 and a negative electrode active material layer 120 formed on one side of the current collector, and the positive electrode layer 170 includes a positive electrode current collector 150 and one side of the current collector. It includes a formed positive electrode active material layer 140. In the battery, the negative electrode active material layer and the positive electrode active material layer are arranged to face each other with the solid electrolyte layer interposed therebetween.

In one embodiment of the present invention, the battery can may be a cylindrical battery can with circular top and bottom portions, or a square battery can with square top and bottom portions. The lower end of the battery can is closed by forming a bottom surface, and has side parts extending upward from the outer periphery of the bottom surface, and the upper end of the battery can is open so that other components can be inserted and/or extracted.

In one embodiment of the present invention, the current collector may be flat, and its size and shape may be prepared to correspond to the size and shape of the bottom surface of the battery can. Additionally, here, the negative electrode current collector may be placed on the lower surface of the negative electrode active material layer so as to be in close contact with it, and the positive electrode current collector may be placed on the upper surface of the positive electrode active material layer so as to be in close contact with it.

Meanwhile, in one embodiment of the present invention, at least one of the positive electrode current collector and the negative electrode current collector includes a flat base and one or more protrusions protruding from one surface of the base. The current collectors (250, 350, 450) may include a flat base (251, 351, 451) and one or more protrusions (252, 352, 452) protruding from one surface of the base, and the protrusions It may be inserted into the electrode active material layer. The height of the protrusion can be appropriately adjusted so that it does not protrude outside the active material layer. One or more protrusions may be formed on the base. The protrusion may have either a needle shape or a branch shape with one or more protruding branches, and protrusions of these shapes may be combined and arranged on one base. The branches of the branch-shaped protrusion 252 may each protrude in a horizontal or diagonal direction.

FIG. 3A schematically shows a current collector 450 including a needle-shaped protrusion 452, and FIG. 3B schematically shows a cross section of a battery including the current collector. In addition, Figure 4 schematically shows a current collector including branch-shaped protrusions, and Figure 4b schematically shows a cross section of a battery including the current collector.

Additionally, in one embodiment of the present invention, the current collector may be provided with a mesh-type protrusion 352 having a three-dimensional network-like structure on one surface of the base. Figure 5 shows a specific embodiment thereof.

Additionally, in a specific embodiment of the present invention, all or part of the surface of the protrusion may be covered with a coating layer containing an electrically conductive material such as a conductive material. In the present invention, for the conductive material component that covers the surface of the protrusion, reference may be made to the content of the conductive material described later.

In this way, when a current collector including a protrusion inserted into the electrode active material layer is used, the electrical conductivity of the electrode is improved.

In one embodiment of the present invention, the material of the battery can may include metal or alloy, and any material commonly used in battery cans may be used without limitation. Non-limiting examples include SUS, tin, aluminum, etc.

Additionally, in one specific embodiment of the present invention, a cap assembly 180 is coupled to the open top of the battery can to seal the battery. Additionally, the battery can may have a beading portion for mounting the cap assembly at the upper end and a crimping portion for sealing the battery.

In the present invention, the electrode assembly is one in which the negative electrode layer, the solid electrolyte layer, and the positive electrode layer are inserted into the battery can in such a way that each layer has a predetermined height. As will be described later regarding the battery manufacturing method according to the present invention, a battery can is used as a mold for forming an electrode assembly and each layer is installed in such a way that the battery can is filled to a predetermined height, so that the final battery that has been manufactured is completed. The electrode assembly and the inner wall of the battery can are in close contact with each other without separation.

In a specific embodiment of the present invention, the entire or partial surface of the inner wall of the battery can may be covered with an insulating material 500. Here, the inner wall may be excluding the bottom surface of the battery can. For example, the inner wall of the battery can may be covered with an insulating layer containing an insulating material. Accordingly, the inner wall of the battery can is prevented from electrochemically reacting with the anode and cathode. In the present invention, the insulating material may include a metal oxide and/or an insulating polymer resin with no or very low electrical conductivity. In one embodiment of the present invention, the insulating layer may have a thickness of about 1㎛ to 10㎛ and can be appropriately adjusted within the above range. Additionally, the insulating layer may further include a buffer layer having elastic force. The buffer layer can prevent the electrode from being separated from the battery can and flowing inside the battery can due to a change in the volume of the electrode due to charging and discharging.

In the present invention, the negative electrode layer includes a negative electrode current collector and a negative electrode active material layer formed on one side of the negative electrode current collector.

The negative electrode current collector may be, for example, a copper thin film. In addition, any material that can be used as an electrode current collector for an electrochemical device may be used and is not particularly limited. These current collectors are not particularly limited as long as they have high conductivity without causing chemical changes in the battery, and include, for example, stainless steel, copper, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel. A surface treated with carbon, nickel, titanium, silver, etc. may be used.

In a specific embodiment of the present invention, the negative electrode current collector may be prepared in a flat shape having the same planar shape as the lower side of the battery can, and is placed at the bottom of the battery can so as to be in close contact with the lower side of the battery can. In one embodiment of the present invention, the battery can itself serves as a conductor connecting the anode and the cathode. Therefore, the negative electrode and the battery can can be electrically connected by the current collector being in close contact with the lower side of the battery can.

The negative electrode active material layer may include a negative electrode active material, a solid electrolyte, and a conductive material, and may optionally further include a binder resin. The negative electrode active material is not particularly limited as long as it can be used as a negative electrode active material in the secondary battery field. Non-limiting examples thereof include carbon such as lithium metal oxide, non-graphitizable carbon, and graphitic carbon; _{Li x} Fe _{2 O 3 (} 0≤x≤1) _, Li _x WO ₂ (0≤x≤1 ₎ , _Sn : Al, B, P, Si, elements of groups 1, 2, and 3 of the periodic table, halogen; metal complex oxides such as 0<x≤1;1≤y≤3;1≤z≤8); lithium metal; lithium alloy; silicon-based alloy; tin-based alloy; SnO, SnO ₂ , PbO, PbO ₂ , Pb ₂ O ₃ , Pb ₃ O ₄ , Sb ₂ O ₃ , Sb ₂ O ₄ , Sb ₂ O ₅ , GeO, GeO ₂ , Bi ₂ O ₃ , Bi ₂ O ₄ , and metal oxides such as Bi ₂ O ₅ ; Conductive polymers such as polyacetylene; Li-Co-Ni based materials; Titanium oxide, etc. may be included, and one or a mixture of two or more selected from these may be included.

In the present invention, the solid electrolyte layer includes an inorganic solid electrolyte and may optionally further include a binder resin. The inorganic solid electrolyte is not limited to specific components as long as it is commonly used as a solid electrolyte component for all-solid-state batteries, and includes one or more of inorganic solid electrolytes such as crystalline solid electrolyte, amorphous solid electrolyte, and glass ceramic solid electrolyte. can do. In the present invention, the solid electrolyte may include a sulfide-based solid electrolyte, and examples of such sulfide-based solid electrolyte include lithium sulfide, silicon sulfide, germanium sulfide, and boron sulfide. A specific example of such an inorganic solid electrolyte is Li _{3 . 833} Sn _{0 . 833} As _{0 . 166} S ₄ , Li ₄ SnS ₄ , Li _{3 . 25} Ge _{0 .25} P _{0. 75} S ₄ , Li ₂ SP ₂ S ₅ , B ₂ S ₃ -Li ₂ S, xLi ₂ S-(100-x)P ₂ S ₅ (x is 70 to 80), Li ₂ S-SiS ₂ -Li ₃ N, Li ₂ SP ₂ S ₅ -LiI, Li ₂ S-SiS ₂ -LiI, Li ₂ SB ₂ S ₃ -LiI, Li ₃ N, LISICON, LIPON(Li _{3+y PO 4 - x N ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​} You can. In one embodiment of the present invention, these inorganic solid electrolyte components can also be applied to the cathode and positive electrode of the present invention.

In addition, the binder resin for the electrolyte layer provides binding force between the materials constituting the battery, and PVdF-based binder resin or acrylic-based binder resin can be used without limitation. Meanwhile, in a specific embodiment of the present invention, when using a sulfide-based solid electrolyte as a solid electrolyte, it is preferable to use a non-polar solvent with a polarity index of 3 or less as a dispersion medium for the electrode slurry containing it, At this time, the binder resin may include a rubber-based binder resin considering solubility. As mentioned above, PVdF-based binder resin or acrylic-based binder resin, which is commonly used as an electrode binder, does not dissolve well in non-polar solvents, making it difficult to manufacture electrode slurry. Therefore, in the present invention, a rubber-based resin is used as the binder resin. The rubber-based binder resin includes natural rubber, butyl-based rubber, bromo-butyl-based rubber, chlorinated butyl-based rubber, styrene-isoprene-based rubber, styrene-ethylene-butylene-styrene-based rubber, and acrylonitrile-butadiene. -Styrene rubber, polybutadiene rubber, nitrile butadiene rubber, styrene butadiene rubber, styrene butadiene styrene rubber (SBS), EPDM (ethylene propylene diene monomer) rubber, BR (ploly butadiene rubber) and HNBR (hydrogenated nitrile). It may include one or more species selected from the group consisting of butadiene rubber. In one embodiment of the present invention, these binder resin components can also be applied to the cathode and anode of the present invention.

In the present invention, the positive electrode layer includes a positive electrode current collector and a positive electrode active material layer formed on one side of the positive electrode current collector. In a specific embodiment of the present invention, the positive electrode active material layer is disposed to be formed on the upper surface of the solid electrolyte layer.

The positive electrode current collector may be, for example, an aluminum thin film. In addition, any material that can be used as an electrode current collector for an electrochemical device may be used and is not particularly limited. These current collectors are not particularly limited as long as they have high conductivity without causing chemical changes in the battery, and include, for example, stainless steel, copper, aluminum, nickel, titanium, calcined carbon, or aluminum or stainless steel. A surface treated with carbon, nickel, titanium, silver, etc. may be used.

In a specific embodiment of the present invention, the positive electrode current collector may be prepared in a flat shape having the same planar shape as the horizontal cross-section of the battery can, and is disposed on the top of the positive electrode active material layer through a positive electrode tab extended or connected thereto. Thus, it is electrically connected to the cap assembly.

The positive electrode active material layer may include a positive electrode active material, a solid electrolyte, and a conductive material, and may optionally further include a binder resin. In the present invention, the positive electrode active material is a layered compound such as lithium manganese composite oxide (LiMn ₂ O ₄ , LiMnO ₂ , etc.), lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ), or one or more transition metals. Compounds substituted with; Chemical formula Li _{1 + x} Mn _{2 - x} O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ , etc.; lithium manganese oxide; lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ , and Cu ₂ V ₂ O ₇ ; Ni site type lithium nickel oxide represented by the formula LiNi _{1 - x} M _x O ₂ where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga and x = 0.01 to 0.3; _{Chemical formula LiMn 2 - x M ​} Lithium manganese complex oxide expressed as Ni, Cu or Zn); LiMn ₂ O ₄ in which part of Li in the chemical formula is replaced with an alkaline earth metal ion; disulfide compounds; Fe ₂ (MoO ₄ ) ₃ and the like may be used, and may be used together, but are not limited to these alone.

In a specific embodiment of the present invention, the conductive material is, for example, graphite, carbon black, carbon fiber or metal fiber, metal powder, conductive whisker, conductive metal oxide, activated carbon, and polyphenylene derivative. It may be any one selected from the group consisting of or a mixture of two or more types of conductive materials. More specifically, natural graphite, artificial graphite, super-p, acetylene black, Ketjen black, channel black, furnace black, lamp black, summer black, denka black, aluminum powder, nickel powder, oxidation. It may be one type selected from the group consisting of zinc, potassium titanate, and titanium oxide, or a mixture of two or more types of conductive materials thereof.

Meanwhile, in the present invention, when the height of the negative electrode active material layer is h1 and the height of the positive electrode active material layer is h3, it is preferable that h1 < h3. Also, in this case, the negative electrode active material layer preferably includes natural graphite, artificial graphite, silicon, etc. as a negative electrode active material, and the positive electrode active material layer preferably includes lithium cobalt oxide, lithium nickel-manganese-cobalt oxide, etc. as a positive electrode active material. The lithium cobalt oxide may include, for example, LiCoO ₂ . Additionally, the lithium nickel-manganese-cobalt oxide is, for example, LiNi _{0 . 6} Co _{0 . 2} Mn _{0 .} It may include one or more of ₂ O ₂ and LiNi _0.8 Co _0.1 Mn _0.1 O ₂ .

Next, a method for manufacturing an all-solid-state battery according to the present invention is provided.

Typically, batteries use a method of manufacturing an electrode assembly through a separate process and inserting the completed electrode assembly into a battery can. However, the present invention does not adopt this method, but manufactures the battery can by using the battery can as an external template for the electrode assembly and embedding each layer in the order of the cathode layer, solid electrolyte layer, and anode layer from the bottom inside the battery can. Accordingly, the electrode assembly can be manufactured in the same or almost the same shape as the battery can, and the battery can and the electrode assembly are in close contact so as not to separate, and as a result, the electrode assembly can maintain a stable shape without flowing within the battery can. In addition, there is no need to perform a separate align process to match the dimensions or specifications of the anode, solid electrolyte layer, and cathode, such as the area or volume, so the process efficiency is high.

In a specific embodiment of the present invention, the all-solid-state battery manufacturing method according to the present invention includes the following steps (S1) to (S6):

First, prepare a battery can made of metal and open at the top (S1).

As described above, in one embodiment of the present invention, the battery can may be prepared with the inner wall covered with an insulating material.

Next, the negative electrode current collector is placed at the bottom of the battery can so that it is in close contact with the bottom of the battery can (S2). The negative electrode current collector may be prepared as a flat plate with the same shape as the horizontal cross section of the battery can. For example, the current collector may be in the shape of a disk with a predetermined thickness, and its diameter may be the same as the inner diameter of the battery can.

Thereafter, a negative electrode active material layer is formed on the upper surface of the negative electrode current collector to have a predetermined height h1 (S3). In one embodiment of the present invention, the negative electrode active material layer can be prepared as follows. An appropriate solvent is prepared and an electrode mixture containing a negative electrode active material, a solid electrolyte, a binder resin, and a conductive material is dispersed therein to prepare a slurry for forming a negative electrode active material layer. The slurry is injected into the inside of the battery can, the solvent is removed through drying, and the slurry is solidified to form a negative electrode active material layer. In one embodiment of the present invention, the drying may be performed under vacuum conditions. Additionally, during drying, the battery can can be heated to a predetermined temperature to promote removal of the solvent. If necessary, the surface of the solidified negative electrode active material layer is pressed to provide an appropriate tap density to the negative electrode active material layer. At this time, the battery can serves as an external frame for the electrode layer, so its shape is maintained stably without deformation of the external shape of the electrode active material layer when pressed, and it has the advantage of preventing problems such as detachment of the active material.

Next, a solid electrolyte layer is formed on the upper surface of the negative electrode active material layer to have a predetermined height h2 (S4). In one embodiment of the present invention, the solid electrolyte layer can be prepared as follows. Prepare an appropriate solvent and disperse the inorganic solid electrolyte in it to prepare a slurry for the electrolyte layer. The slurry for the electrolyte layer may further include a binder resin. The slurry is placed inside the battery can, the solvent is removed, and the slurry is solidified to form an electrolyte layer. In one embodiment of the present invention, the drying may be performed under vacuum conditions. Additionally, during drying, the battery can can be heated to a predetermined temperature to promote removal of the solvent. If necessary, the surface of the solidified electrolyte layer is pressed to provide an appropriate tap density to the electrolyte layer. At this time, the battery can serves as the outer shape of the electrolyte layer, so its shape is maintained stably without deformation of the outer shape of the electrolyte layer when pressurized.

Afterwards, a positive electrode active material layer is formed on the upper surface of the solid electrolyte layer to have a predetermined height h3 (S5). For the method of forming the positive electrode active material layer, refer to the information described in the step of forming the negative electrode active material layer. In the next step, a positive electrode current collector is placed on the upper surface of the positive electrode active material layer (S6).

In a specific embodiment of the present invention, the positive active material layer may be pressurized after solidifying the slurry and placing a positive current collector on the surface. At this time, the positive electrode current collector can serve as a jig, and by applying pressure, an appropriate tap density can be provided to the positive electrode active material layer and the adhesion between the current collector and the positive active material layer can be increased.

Meanwhile, in a specific embodiment of the present invention, when the current collector has a structure including a protrusion, the above-exemplified process sequence can be appropriately supplemented to ensure that the protrusion is inserted into the electrode active material.

For example, when the current collector includes needle-shaped or branch-shaped protrusions, the steps (S1) to (S4) above can be applied to the arrangement of the current collector and the formation of the negative electrode active material layer. Meanwhile, when forming the positive electrode active material layer in step (S5), the protrusion may be inserted into the slurry before the slurry is solidified, and in the subsequent step, the base may be placed on the upper surface of the positive active material layer and pressed. For this purpose, the current collector can be prepared with the protrusions and the base separated (FIG. 6). When forming the electrode active material layer, the protrusions are inserted into the active material layer and when pressed, the ends of the protrusions and the base come into contact so that they can be electrically connected. It can be done. Meanwhile, in one embodiment of the present invention, in order to ensure that the end of the protrusion and the base are well electrically connected, a groove 453 of a shape corresponding to the end of the protrusion is formed on the surface of the base so that the end of the protrusion is inserted into the base. It can be inserted to a predetermined depth.

The above detailed description is illustrative of the present invention. Additionally, the foregoing is intended to illustrate preferred embodiments of the present invention, and the present invention can be used in various other combinations, modifications, and environments. That is, changes or modifications can be made within the scope of the inventive concept disclosed in this specification, a scope equivalent to the written disclosure, and/or within the scope of technology or knowledge in the art. The above-described embodiments illustrate the best state for implementing the technical idea of the present invention, and various changes required for specific application fields and uses of the present invention are also possible. Accordingly, the detailed description of the invention above is not intended to limit the invention to the disclosed embodiments. Additionally, the appended claims should be construed to include other embodiments as well.

10 Conventional cylindrical secondary battery, 12 electrode assembly, 12a anode, 12b separator, 12c cathode, 13 battery case, 15 center pin, 14 cap assembly

100 All-solid-state battery according to the present invention, 180 cap assembly, 130 negative electrode current collector, 120 negative electrode active material layer, 160 negative electrode layer, 110 solid electrolyte layer, 130 battery case, 140 positive electrode active material layer, 150 positive electrode current collector, 170 positive electrode layer, 450 current collector, 451 base, 452 needle-shaped protrusion, 251 base, 252 branched protrusion, 351 base, 352 mesh-shaped protrusion, 350 current collector, 453 groove, 500 insulating material

Claims (9)

A battery can made of metal and open at the top; and
It includes an electrode assembly inserted into the battery can,
The electrode assembly has a layered structure in which a cathode layer, a solid electrolyte layer, and an anode layer are sequentially stacked from the bottom of the battery can,
The negative electrode layer includes a negative electrode current collector and a negative electrode active material layer formed on one surface of the current collector,
The positive electrode layer includes a positive electrode current collector and a positive electrode active material layer formed on one surface of the current collector, and the negative electrode active material layer and the positive electrode active material layer face each other through the solid electrolyte layer,
When the height of the negative electrode active material layer is h1 and the height of the positive electrode active material layer is h3, h1 is less than h3 and at least one of the positive electrode current collector and the negative electrode current collector is a flat base and one protruding from one surface of the base. It includes one or more protrusions, the protrusions are inserted into the electrode active material layer, and the protrusions are branch-shaped or mesh-shaped with a network-like structure,
All or part of the surface of the protrusion is covered with a coating layer containing an electrically conductive material,
An all-solid-state battery wherein the inner wall of the battery can is covered with an insulating layer containing an insulating material, the insulating layer has a thickness of 1㎛ to 10㎛, and the insulating layer includes a buffer layer having elastic force.
According to paragraph 1,
The battery is an all-solid-state battery that is sealed by installing a cap assembly on the open top.
According to paragraph 1,
The electrode assembly is manufactured by sequentially embedding a cathode layer, a solid electrolyte layer, and an anode layer in a battery can, and the electrode assembly and the inner wall of the battery can are in close contact with each other so as not to be spaced apart, an all-solid-state battery.
delete According to paragraph 1,
An all-solid-state battery, wherein the solid electrolyte includes an inorganic solid electrolyte.
According to clause 5,
An all-solid-state battery, wherein the inorganic solid electrolyte includes a sulfide-based solid electrolyte.
delete delete (S1) preparing a battery can made of metal and open at the top;
(S2) placing a negative electrode current collector at the bottom of the battery can so that it is in close contact with the bottom of the battery can;
(S3) forming a negative electrode active material layer on the upper surface of the negative electrode current collector to have a predetermined height h1;
(S4) forming a solid electrolyte layer to have a predetermined height h2 on the upper surface of the negative electrode active material layer;
(S5) forming a positive electrode active material layer on the upper surface of the solid electrolyte layer to have a predetermined height h3; and
(S6) placing a positive electrode current collector on the upper surface of the positive electrode active material layer,
When the height of the negative electrode active material layer is h1 and the height of the positive electrode active material layer is h3, h1 is less than h3 and at least one of the positive electrode current collector and the negative electrode current collector is a flat base and one protruding from one surface of the base. It includes the above protrusions, the protrusions are inserted into the electrode active material layer, and the protrusions are branch-shaped or mesh-shaped with a net-like structure, and all or part of the surface of the protrusions are covered with a coating layer containing an electrically conductive material, ,
The inner wall of the battery can is covered with an insulating layer containing an insulating material, the insulating layer has a thickness of 1㎛ to 10㎛, and the insulating layer includes a buffer layer having elastic force. Manufacture of an all-solid-state battery method.

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