All-solid-state battery and method of manufacturing all-solid-state battery

Abstract

An embodiment of the present disclosure may provide a method of manufacturing an all-solid-state battery, comprising: a primary punching step of punching at least one portion of a second film layer including an insulating material to form an insulation accommodation unit having an insulation member accommodated therein; an adhesion step of adhering the second film layer to a first film layer including an insulating material; and a secondary punching step of punching the first film layer and the second film layer together to form a positive electrode accommodation unit and a pre-removal line in a primary film assembly; an assembly step of stacking, in the primary film assembly, a positive electrode, a positive electrode current collector, a solid electrolyte, a negative electrode and a negative electrode current collector; and a cutting step of cutting a portion of the primary film assembly along a cut line connected to the pre-removal line to form a secondary film assembly.

Description

All-solid-state battery and method for manufacturing an all-solid-state battery

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0185204 filed December 12, 2024 and Korean Patent Application No. 10-2025-0017358 filed February 11, 2025, and all contents disclosed in the documents of said Korean patent applications are incorporated herein as part of this specification.

[0002] The present invention relates to an all-solid-state battery and a method for manufacturing an all-solid-state battery.

[0003] Unlike primary batteries, secondary batteries can be charged and discharged, so they can be applied in various fields such as digital cameras, mobile phones, laptops, hybrid cars, and electric vehicles. Secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-hydrogen batteries, and lithium-ion batteries are widely used.

[0004] Lithium-ion rechargeable batteries, a type of lithium secondary battery containing an electrolyte and a separator, have the disadvantage of a high risk of electrolyte leakage and fire. As an alternative, all-solid-state batteries are being developed that use non-flammable solids as electrolytes, which have a low risk of fire and explosion.

[0005] In the process of manufacturing all-solid-state batteries, a compression process (e.g., Warm Isostatic Pressing (WIP) method) is applied to the laminate after stacking and assembling the positive electrode, negative electrode, solid electrolyte, positive tab, and negative tab to stabilize the structure of the laminate and improve energy density.

[0006] Meanwhile, referring to FIGS. 2 and 3, when performing the compression process, the all-solid-state battery is pre-packaged into a compression process pouch (P) as shown in FIG. 2 and then pressurized. In the compression process, the compression process pouch (P) adheres to the outer surface of the all-solid-state battery. At this time, a step is formed between the electrode tabs (positive tab (210), negative tab (410)) of the all-solid-state battery and the other outer surface of the all-solid-state battery, creating a void (E). During the process of the compression process pouch (P) filling the void (E) and adhering to it, it extends from the corner area of ​​the void (E) as shown in FIG. 3 below, generating tensile force on the electrode tabs (210, 410). Due to this tensile force, a problem occurs in which the electrode tabs (210, 410) are disconnected (C).

[0007] The present invention is designed to solve at least some of the problems of the prior art described above, and is intended to prevent the disconnection of electrode tabs occurring during the compression process in the manufacture of all-solid-state batteries.

[0008] To achieve the above objective, a method for manufacturing an all-solid-state battery according to an embodiment of the present invention may include: a first punching step of punching at least a portion of a second film layer containing an insulating material to form an insulating receiving portion in which an insulating member is received; an adhesive step of adhering the second film layer to a first film layer containing an insulating material; a second punching step of punching the first film layer and the second film layer together to form an anode receiving portion and a pre-removal line in a first film assembly; an assembly step of stacking an anode, an anode current collector, a solid electrolyte, a cathode, and a cathode current collector on the first film assembly; and a cutting step of cutting a portion of the first film assembly along a cutting line connected to the pre-removal line to form a second film assembly.

[0009] According to one embodiment, the positive current collector includes a positive tab protruding to one side, and the insulating member surrounds at least a portion of the positive tab, and the width and length of the insulating receiving portion formed in the first punching step may be equal to or greater than the width and length of the insulating member.

[0010] According to one embodiment, the second film layer comprises a second film including an insulating material and a second adhesive layer that bonds two adjacent layers including the second film, and the bonding step may be a step of bonding the second film and the first film layer with the second adhesive layer.

[0011] According to one embodiment, the pre-removal line formed in the second punching step includes a first line and a second line, wherein the first line is spaced apart from the edge line, and the edge line is formed on at least one of the edge of the positive current collector with the positive tab protruding and the edge of the negative current collector with the negative tab protruding, and the second line may have one end connected to each end of the first line.

[0012] According to one embodiment, the first line may be formed to be parallel to the edge line.

[0013] According to one embodiment, the second line is inclined with respect to the first line, and the other end may be spaced further from the edge line than the first line.

[0014] According to one embodiment, the cutting line starts from the other end of the second line and may be spaced apart from the edge line.

[0015] According to one embodiment, the assembly step may be a step of stacking the positive current collector, the positive electrode, the solid electrolyte, the negative electrode, and the negative current collector in order, and receiving the positive electrode and the insulating member in the positive receiving part and the insulating receiving part, respectively.

[0016] According to one embodiment, the assembly step may include the step of laminating a third film layer on the outside of the anode current collector.

[0017] According to one embodiment, the third film layer is composed of a third film comprising an insulating material and a third adhesive layer that bonds two adjacent layers including the third film, and may include the insulating receiving portion.

[0018] According to one embodiment, the assembly step may be a step of adhering a release liner to at least one of the first film layer and the second film layer.

[0019] According to one embodiment, the cutting step may include a step of removing the release liner together.

[0020] According to one embodiment, the method may further include a compression step in which the structure formed in the assembly step is pre-packaged into a pouch and then compressed.

[0021] According to one embodiment, the method may further include an electrical connection step in which a plurality of structures formed in the cutting step are stacked and then each is electrically connected.

[0022] According to one embodiment, the method may further include a packaging step for packaging a structure formed in the electrical connection step.

[0023] Meanwhile, an all-solid-state battery according to an embodiment of the present invention comprises a positive electrode, a solid electrolyte, a negative electrode, a positive current collector stacked on one side of the positive electrode and electrically connected to the positive electrode and including a positive electrode tab protruding to one side, a negative current collector stacked on one side of the negative electrode and electrically connected to the negative electrode and including a negative electrode tab protruding to one side, and a film assembly provided in the same layer as the positive electrode and surrounding the perimeter of the positive electrode, wherein at least one region of the side of the film assembly may be recessed along a pre-removal line in a direction opposite to the protruding direction of the positive electrode tab or the negative electrode tab.

[0024] According to one embodiment, the pre-removal line may be positioned so that at least a portion overlaps with the positive tab or the negative tab in the stacking direction.

[0025] According to one embodiment, the pre-removal line includes a first line and a second line, wherein the first line is spaced apart from the edge line of one side of the positive current collector on which the positive tab protrudes or one side of the negative current collector on which the negative tab protrudes, and one end of the second line may be connected to the first line.

[0026] According to one embodiment, the first line may be arranged to overlap with the positive tab or the negative tab in the stacking direction.

[0027] According to one embodiment, the first line may be located closer to the edge line than the second line.

[0028] According to one embodiment of the present disclosure, in manufacturing an all-solid-state battery, it is possible to prevent the disconnection of the electrode tab that occurs during the compression process.

[0029] Figure 1 is a plan view illustrating a basic unit cell of an all-solid-state battery.

[0030] FIG. 2 is a cross-sectional view along the cross-sectional line B-B' of FIG. 1, showing the state in which a basic unit cell of a conventional all-solid-state battery is pre-packaged into a pouch for a compression process.

[0031] Figure 3 is a cross-sectional view along the cross-sectional line B-B' of Figure 1 showing the state in which a break occurs in the electrode tab as a result of performing a compression process on the basic unit cell of a conventional all-solid-state battery.

[0032] FIG. 4 is a cross-sectional view along the cross-sectional line B-B' of FIG. 1 illustrating the compression process performed on a basic unit cell of a first type of all-solid-state battery according to one embodiment of the present disclosure.

[0033] FIG. 5 is a cross-sectional view showing the state of a basic unit cell of a first type of all-solid-state battery after performing a compression process according to one embodiment of the present disclosure, along the cross-sectional line B-B' of FIG. 1.

[0034] FIG. 6 is a schematic diagram illustrating a method for manufacturing an all-solid-state battery according to one embodiment of the present disclosure.

[0035] Figure 7 is an enlarged plan view of the electrode assembly in the cutting step of Figure 6.

[0036] FIG. 8 is a cross-sectional view showing the state of a basic unit cell of a second type of all-solid-state battery before performing a compression process according to another embodiment of the present disclosure, along the cross-sectional line B-B' of FIG. 1.

[0037] FIG. 9 is a cross-sectional view showing the state of a basic unit cell of a second type of all-solid-state battery after performing a compression process according to another embodiment of the present disclosure, along the cross-sectional line B-B' of FIG. 1.

[0038] FIG. 10 is a cross-sectional view showing the state of a basic unit cell of a third type of all-solid-state battery before performing a compression process according to another embodiment of the present disclosure, along the cross-sectional line B-B' of FIG. 1.

[0039] FIG. 11 is a cross-sectional view showing the state of a basic unit cell of a third type of all-solid-state battery after performing a compression process according to another embodiment of the present disclosure, along the cross-sectional line B-B' of FIG. 1.

[0040] In describing the embodiments of the present disclosure, the terms used have been selected to be as widely used as possible, taking into account their functions within the present disclosure; however, these terms may vary depending on the intent of those skilled in the art, case law, the emergence of new technologies, etc. Additionally, in specific cases, terms may be selected at the applicant's discretion, and in such cases, their meanings may be described in detail in the relevant explanatory section. Therefore, the terms used in the present disclosure are not merely names, but may be defined based on their meanings and the overall content of the present disclosure.

[0041] The suffix "part" for components used in this specification is assigned or used interchangeably solely for the sake of ease of drafting the specification and may not have a distinct meaning or role in itself. Furthermore, in describing the embodiments included in this disclosure, if it is determined that a detailed description of related prior art could obscure the essence of the embodiments included in this disclosure, such detailed description may be omitted. Additionally, the attached drawings are intended only to facilitate understanding of the embodiments included in this disclosure, and the technical concept of this disclosure is not limited by the attached drawings; it should be understood that the technical concept and scope of this disclosure include all modifications, equivalents, and substitutions.

[0042] Terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but said components are not limited by said terms, and said terms may be used only for the purpose of distinguishing one component from another.

[0043] When it is stated that a component is "connected" or "connected" to another component, it can be understood that it may be directly connected or connected to that other component, or that there may be other components in between. On the other hand, when it is stated that a component is "directly connected" or "directly connected" to another component, it can be understood that there are no other components in between.

[0044] In this specification, singular expressions may include plural expressions unless the context clearly indicates otherwise.

[0045] Terms such as "comprising" or "having" as used in this specification are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should not be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0046] The expression "at least one of a, b, and c" as described in this specification may include 'a alone', 'b alone', 'c alone', 'a and b', 'a and c', 'b and c', or 'a, b, and c all'.

[0047] Embodiments of the present disclosure are described below with reference to the attached drawings so that those skilled in the art can easily implement them. However, the present disclosure may be embodied in various different forms and is not limited to the embodiments described herein.

[0048] Embodiments of the present disclosure will be described in detail below with reference to the drawings. Identical drawing reference numerals refer to identical configurations. An alphabet following a number may be used when the configurations need to be distinguished. For example, drawing reference numerals 1000, 1000a, and 1000b may refer to configurations that share common described features, and drawing reference numerals 1000a and 1000b may indicate a state in which a configuration corresponding to 1000 is provided in different locations.

[0049] FIG. 1 is a plan view illustrating a basic unit cell (10) of an all-solid-state battery.

[0050] The basic unit cell (10) of the all-solid-state battery referred to in the present disclosure may mean a state before the all-solid-state battery is completed. For example, the basic unit cell (10) may be an assembly in which a negative electrode (300), a positive electrode (100), and a solid electrolyte (500) are stacked, and may mean a state before packaging. An all-solid-state battery may be manufactured by assembling at least one basic unit cell (10).

[0051] The basic unit cell (10) of the all-solid-state battery shown in FIG. 1 is illustrated to show a cross-sectional line for explaining a conventional all-solid-state battery and an all-solid-state battery according to one embodiment of the present disclosure, and does not limit the shape of the conventional all-solid-state battery or the all-solid-state battery according to one embodiment of the present disclosure.

[0052] The compression process described in this disclosure may be a process using the WIP (Warm Isostatic Pressing) method. The compression process is a process of pre-packaging the basic unit cell (10) of the electrode assembly with a compression process pouch and then applying pressure. The compression process is not necessarily limited to the WIP method and is a concept that includes similar methods.

[0053] FIG. 4 is a cross-sectional view along the cross-sectional line B-B' of FIG. 1 showing the compression process performed on a basic unit cell (10a) of a first type of all-solid-state battery according to one embodiment of the present disclosure, and FIG. 5 is a cross-sectional view along the cross-sectional line B-B' of FIG. 1 showing the state of the basic unit cell (10a) of a first type of all-solid-state battery after the compression process performed according to one embodiment of the present disclosure.

[0054] Referring first to FIG. 5, an all-solid-state battery according to one embodiment of the present disclosure may include a positive electrode (100), a solid electrolyte (500), and a negative electrode (300). The positive electrode (100), the solid electrolyte (500), and the negative electrode (300) may be stacked sequentially. Conversely, it is also possible for the negative electrode (300), the solid electrolyte (500), and the positive electrode (100) to be stacked sequentially. An all-solid-state battery according to one embodiment of the present disclosure may include a stacked body. The stacked body may be an assembly in which the positive electrode (100), the solid electrolyte (500), and the negative electrode (300) are stacked sequentially.

[0055] A solid-state battery according to one embodiment of the present disclosure may include a negative electrode current collector (400). The negative electrode current collector (400) may be stacked on the outer side of the negative electrode of a laminate equipped with a negative electrode (300) and electrically connected to the negative electrode (300). The outer side referred to herein may mean the upper or lower side in the stacking direction relative to the laminate. The negative electrode current collector (400) may be stacked on one surface of the negative electrode (300) and electrically connected to the negative electrode (300). The negative electrode current collector (400) may include a negative electrode tab (410) protruding to one side. The negative electrode tab (410) may be formed with at least a portion protruding in a direction intersecting the stacking direction.

[0056] An all-solid-state battery according to one embodiment of the present disclosure may include a positive current collector (200). The positive current collector (200) may be stacked on the outer side of the positive side of a stacked body equipped with a positive electrode (100) and electrically connected to the positive electrode (100). The positive current collector (200) may be stacked on one side of the positive electrode (100) and electrically connected to the positive electrode (100). The positive current collector (200) may include a positive electrode tab (210) protruding to one side. The positive electrode tab (210) may be formed so that at least a portion protrudes in a direction intersecting the stacking direction.

[0057] A solid-state battery according to one embodiment of the present disclosure may include a first film layer (610). The first film layer (610) may occupy a portion of the height in the stacking direction of the anode (100). For example, the first film layer (610) may be located within the height range of the anode (100) in the stacking direction, and the thickness of the first film layer (610) may be formed to be smaller than the thickness of the anode (100). The first film layer (610) may wrap around the perimeter of the anode (100). The perimeter referred to herein may be a perimeter located on a plane intersecting the stacking direction. For example, referring together with FIG. 6, the first film layer (610) may include the shape of a picture frame in which an anode receiving portion (640), which is an empty space in the center, is formed, and the anode (100) may be filled into the anode receiving portion (640).

[0058] A first film layer (610) according to one embodiment of the present disclosure may include a first film (611) and a first adhesive layer (612). The first film layer (610) may be a film comprising an insulating material. The first adhesive layer (612) may bond two adjacent layers including the first film (611). The first adhesive layer (612) may be disposed between the first film (611) and another layer and may be a member for bonding the first film (611) and another layer. For example, the first adhesive layer (612) may bond the first film (611) and a solid electrolyte (500).

[0059] An all-solid-state battery according to one embodiment of the present disclosure may include an insulating member (220). The insulating member (220) may wrap at least a portion of the positive tab (210). For example, the insulating member (220) may be attached to one side of the positive tab (210) or to both sides of the positive tab (210). In this case, one side or both sides may refer to one side or both sides in the stacking direction. FIGS. 4 and 5 illustrate the case where the insulating member (220) is attached to both sides of the positive tab (210).

[0060] A solid-state battery according to one embodiment of the present disclosure may include a second film layer (620). The second film layer (620) may occupy the remaining portion of the height in the stacking direction of the positive electrode (100). That is, the second film layer (620) may be formed in the same layer as the insulating member (220) in the stacking direction, and the sum of the thicknesses of the first film layer (610) and the second film layer (620) may be equal to the thickness of the positive electrode (100). The second film layer (620) may include an insulating receiving portion (630). The insulating receiving portion (630) may accommodate at least a portion of the insulating member (220). The second film layer (620) may wrap around at least a portion of the perimeter of the positive electrode (100). For example, it may include a picture frame shape that includes an anode receiving portion (640), which is an empty space in the center where the anode (100) is located, similar to the first film layer (610). In this case, it may be a shape in which an insulating receiving portion (630) is formed on one side.

[0061] A second film layer (620) according to one embodiment of the present disclosure may include a second film (621) and a second adhesive layer (622). The second film (621) may be a film comprising an insulating material. The second adhesive layer (622) may bond two adjacent layers including the second film (621). The second adhesive layer (622) may be disposed between the second film (621) and another layer and may be a member for bonding the second film (621) and another layer. For example, the second adhesive layer (622) may bond the second film (621) and the first film layer (610).

[0062] An insulating receiving portion (630) according to one embodiment of the present disclosure may be formed by removing at least a portion of the second film layer (620). For example, a portion of the second film (621) may be removed by punching a portion corresponding to the width of the insulating receiving portion (630) in the second film (621).

[0063] A basic unit cell (10a) of an all-solid-state battery according to one embodiment of the present disclosure may be in a form in which a first film layer (610) and a second film layer (620) are stacked again in at least a part of the composition and a specific area of ​​the stack, as shown in FIG. 5, in a stack of a positive current collector (200), a positive electrode (100), a solid electrolyte (500), a negative electrode (300), and a negative current collector (400).

[0064] The basic unit cell (10) of the all-solid-state battery can have various types of stacked structures, and the basic unit cell (10a) of the all-solid-state battery illustrated in FIGS. 5 and 6 may correspond to the first type. The basic unit cell (10a) of the first type of all-solid-state battery may be provided with a plurality of film assemblies (600a, 600b), insulating members (220), positive electrodes (100), solid electrolytes (500), negative electrodes (300), and negative electrode current collectors (400), and may be stacked to be symmetrical with respect to the positive electrode current collector (200). With respect to the positive current collector (200), the positive electrode (100), the solid electrolyte (500), the negative electrode (300), and the negative current collector (400) may be stacked in order downwards, and with respect to the positive current collector (200), the positive electrode (100), the solid electrolyte (500), the negative electrode (300), and the negative current collector (400) may be stacked in order upwards. The first type of basic unit cell (10a) may include one positive current collector (200) and two negative current collectors (400), with the positive current collector (200) located in the center and the negative current collectors (400) located on each side of the basic unit cell (10a).

[0065] A solid-state battery can be formed by assembling at least one basic unit cell (10a) in succession, and at least one of a specific component, such as a positive current collector (200) or a negative current collector (400), may be shared with another basic unit cell (10a). The components constituting the basic unit cell (10a) may be stacked in various orders, and the basic unit cell (10a) illustrated in FIG. 5 may also be just one of several types that can be formed.

[0066] However, if a compression process is performed on a solid-state battery of the form shown in Fig. 5 in order to manufacture a solid-state battery of the form shown in Fig. 5, problems as illustrated in Figs. 2 and 3 may occur. To solve this, referring to Fig. 2, it is necessary to fill the empty space (E) of the basic unit cell (10) of the electrode assembly with a different configuration before performing the compression process.

[0067] Referring to FIG. 4, in order to fill the empty space (E) described above, the first film layer (610) and the second film layer (620) of the all-solid-state battery according to one embodiment of the present disclosure may be extended in a direction toward the electrode tab (hereinafter, the electrode tab is described as including a positive electrode tab (210) and a negative electrode tab (410).

[0068] According to one embodiment of the present disclosure, the first film layer (610) and the second film layer (620) may overlap with the electrode tabs (210, 410) in the stacking direction. For example, the first film layer (610) and the second film layer (620) may extend in the longitudinal direction to the end of the electrode tabs (210, 410). The longitudinal direction is a direction intersecting the stacking direction and may be the direction in which the electrode tabs (210, 410) protrude from the current collector (200, 400). Therefore, when performing the compression process, a void space (E) as shown in FIG. 2 is not formed around the electrode tabs (210, 410), so a tensile force as shown in FIG. 3 may not be generated.

[0069] At this time, the all-solid-state battery according to one embodiment of the present disclosure may include a release liner (800). The release liner (800) may be adhered to at least one of the first film layer (610) and the second film layer (620). The release liner (800) may be configured to cover the adhesive surface of the adhesive layer and to be easily detached from the adhesive layer. The release liner (800) may be positioned so as to come into contact with the pouch (P) for the compression process and the adhesive layer located at the outermost edge, such as the first adhesive layer (612), thereby preventing the adhesive layer from adhering to the pouch (P). Additionally, it may compensate for a gap (G) that may occur, such as the negative electrode tab (410) of FIG. 4, thereby reducing the size of the gap (G). The gap (G) depicted in Fig. 4 is exaggerated compared to the actual gap (G), and since the height of the gap (G) is very low, even if a compression process is performed, the pouch (P) for the compression process may not be inserted into the gap (G) as in Fig. 3.

[0070] The removal area (R) indicated by the dotted line in FIG. 4 is an area that is removed after performing a compression process. After the removal area (R) is removed, the basic unit cell (10a) of the all-solid-state battery in FIG. 4 can form a structure similar to the basic unit cell (10a) of the all-solid-state battery in FIG. 5.

[0071] FIG. 6 is a schematic diagram illustrating a method for manufacturing an all-solid-state battery according to one embodiment of the present disclosure, and FIG. 7 is an enlarged plan view illustrating an electrode assembly of the cutting step (S600) of FIG. 6.

[0072] Hereinafter, a method for manufacturing an all-solid-state battery according to one embodiment of the present disclosure will be described with reference to FIGS. 6 and 7 together with FIGS. 2 and FIGS. 4 and 5.

[0073] A method for manufacturing an all-solid-state battery according to one embodiment of the present disclosure may include a first punching step (S100). The first punching step (S100) may be a step of pre-forming an insulating receiving portion (630) in a second film layer (620). The insulating receiving portion (630) may be formed by cutting a portion corresponding to the perimeter of the insulating receiving portion (630). The insulating receiving portion (630) may be formed by punching at least a portion of the second film layer (620). At this time, the insulating receiving portion (630) may be formed at a position corresponding to the insulating member (220) so as to accommodate the insulating member (220). The width and length of the insulating receiving portion (630) formed in the first punching step (S100) may be formed to be equal to or greater than the width and length of the insulating member (220) so as to accommodate the entire insulating member (220). The first film layer (610) and the second film layer (620) can be extended further in the longitudinal direction than the insulating receiving portion (630) to form a removal area (R) that fills the empty space (E) of FIG. 2. At least a portion of the insulating member (220) formed in the first punching step (S100) can be removed in the cutting step (S600) described later.

[0074] A method for manufacturing an all-solid-state battery according to one embodiment of the present disclosure may include an adhesive step (S200). The adhesive step (S200) may be a step of adhering a second film layer (620) to a first film layer (610). A second film layer (620), which has a portion removed by a first punching step (S100), may be adhered to the first film layer (610). At this time, a second adhesive layer (622) may be disposed between the second film (621) and the first film layer (610). The adhesive step (S200) may be a step of adhering the second film (621) and the first film layer (610) with the second adhesive layer (622).

[0075] A method for manufacturing an all-solid-state battery according to one embodiment of the present disclosure may include a second punching step (S300). The second punching step (S300) may be a step of forming a first film assembly (600a). The first film assembly (600a) may form an outer boundary (602) and an inner boundary (601) of the first film assembly (600a) by punching the first film layer (610) and the second film layer (620) together. At least a portion of the first film assembly (600a) may be removed to form an anode receiving portion (640) and a pre-removal line (650) in the first film assembly (600a). For example, the outer boundary (602) of the first film layer (610) and the second film layer (620) can be cut to form the edge of the first film assembly (600a), and the inner boundary (601) can be cut to form the positive electrode receiving portion (640). The pre-removal line (650) may be a line that is cut in advance to easily remove the removal area (R) of FIG. 4. This may be so that the components of the all-solid-state battery, such as the insulating member (220) and electrode tabs (210, 410), positive electrode (100), negative electrode (300), and solid electrolyte (500), are not cut together with the removal area (R) during the cutting step (S600) to be described later. After the second punching step (S300), the first film assembly (600a) including the first film layer (610) and the second film layer (620) can be formed in the shape of a picture frame. The pre-removal line (650) may include an anode pre-removal line (650a) located close to the anode tab (210) and a cathode pre-removal line (650b) located close to the cathode tab (410). The specific shape of the pre-removal line (650) will be described later.

[0076] A method for manufacturing an all-solid-state battery according to one embodiment of the present disclosure may include an assembly step (S400). The assembly step (S400) may be a step of stacking a positive electrode (100), a positive electrode current collector (200), a solid electrolyte (500), a negative electrode (300), and a negative electrode current collector (400) on a primary film assembly (600a). The assembly step (S400) may be a step of stacking the positive electrode current collector (200), the positive electrode (100), the solid electrolyte (500), the negative electrode (300), and the negative electrode current collector (400) in order, and accommodating the positive electrode (100) and the insulating member (220) in the positive electrode receiving portion (640) and the insulating receiving portion (630), respectively. For example, after inserting the positive electrode (100) into the positive electrode receiving portion (640), the positive electrode current collector (200) may be stacked on the outside of the positive electrode (100). At this time, the positive current collector (200) has a positive tab (210) formed that protrudes to at least one side, and an insulating member (220) is attached to at least a part of the positive tab (210). For the sake of understanding, the positive current collector (200) illustrated in FIG. 6 is depicted as having the insulating member (220) attached only to one side of the positive tab (210). Therefore, cases where the insulating member (220) is attached to both sides of the positive tab (210) are excluded. The insulating member (220) can be received in an insulating receiving portion (630) formed by the first punching step (S100). Subsequently, a solid electrolyte (500), a negative electrode (300), and a negative current collector (400) can be stacked and assembled to form a basic unit cell (10). However, the assembly order described above may be modified within an appropriate range.

[0077] A method for manufacturing an all-solid-state battery according to one embodiment of the present disclosure may include a compression step (S500). The compression step (S500) may be a step in which a compression process is performed to improve the energy density and structural stability of the all-solid-state battery after the basic unit cell (10) is completed. As an example of a compression process, a Warm Isostatic Pressing (WIP) method may be performed. The compression step (S500) may be a step of pre-packaging the structure formed in the assembly step (S400) into a compression process pouch (P) and then compressing it, and the process may be as illustrated in FIG. 4.

[0078] A method for manufacturing an all-solid-state battery according to one embodiment of the present disclosure may include a cutting step (S600). The cutting step (S600) may be a step of forming a secondary film assembly (600b). In the cutting step (S600), a portion of the primary film assembly (600a) may be cut along a cutting line (L2) connected to a pre-removal line (650) to form a secondary film assembly (600b). In other words, the cutting step (S600) may be a step of removing the removal area (R) of FIG. 4. Referring to FIG. 7, the pre-removal line (650) may be positioned so that at least a portion of it overlaps with the positive electrode tab (210) or the negative electrode tab (410) in the stacking direction. The stacking direction referred to herein may be the direction in which the positive electrode (100), the solid electrolyte (500), and the negative electrode (300) are stacked. The pre-removal line (650) may include a first line (651) and a second line (652). The first line (651) may be a line parallel to the edge line (L1). The edge line (L1) referred to herein may be an edge formed on at least one of the edge of the positive current collector (200) on which the positive tab (210) protrudes and the edge of the negative current collector (400) on which the negative tab (410) protrudes.

[0079] According to one embodiment of the present disclosure, the first line (651) may be spaced apart from the edge line (L1). The first line (651) may be formed parallel to the edge line (L1). The first line (651) may be positioned to overlap with the positive tab (210) or the negative tab (410) in the stacking direction.

[0080] According to one embodiment of the present disclosure, the second line (652) may be a line with one end connected to each end of the first line (651). The second line (652) may be a line inclined to the first line (651). The other end of the second line (652) may be spaced further from the edge line (L1) than the first line (651). For example, the further the second line (652) is from the first line (651), the further it may be from the edge line (L1). The first line (651) may be located in the opposite direction to the protrusion direction of the positive tab (210) or negative tab (410) relative to the second line (652). In other words, the first line (651) may be positioned closer to the center of the laminate than the adjacent line.

[0081] For energy density, the first film layer (610) and the second film layer (620) may be as small as possible. Accordingly, the first line (651) can be placed close to the laminate in which the anode (100), solid electrolyte (500), and cathode (300) are stacked. However, if cutting along the first line (651), there may be a risk of damaging the laminate. Therefore, the second line (652) can be placed so as to be connected to the first line (651) while being spaced apart from the laminate at a predetermined distance. The cutting line (L2) starts from the other end of the second line (652) and can be spaced apart from the edge line (L1). The cutting line (L2) may not overlap with the anode (100), positive current collector (200), cathode (300), and negative current collector (400) in the stacking direction.

[0082] The removal area (R) may include a portion of the insulation receiving portion (630). The insulation receiving portion (630) may be formed with an area larger than necessary to accommodate all of the insulation member (220) in the first punching step (S100), and a portion thereof may be included in the removal area (R) and removed together. Accordingly, the first line (651) may overlap with the insulation receiving portion (630) in the stacking direction.

[0083] A cutting step (S600) according to one embodiment of the present disclosure may include a step of removing the release liner (800) together. The release liner (800) is provided so that it can be easily separated from the adhesive layer and can be easily removed by a worker or the like without a separate cutting method.

[0084] The method for manufacturing an all-solid-state battery of the present disclosure may further include an electrical connection step (S700). The electrical connection step (S700) may be a step of electrically connecting each of the structures formed in the cutting step (S600) after stacking a plurality of them. The electrical connection may be a method of welding the same positive tab (210) or negative tab (410) together.

[0085] The method for manufacturing an all-solid-state battery of the present disclosure may further include a packaging step (S800). The packaging step (S800) may be a step of packaging a structure formed in an electrical connection step (S700). An all-solid-state battery may be completed by performing packaging.

[0086] FIG. 8 is a cross-sectional view showing the state of a basic unit cell (10b) of a second type of all-solid-state battery according to another embodiment of the present disclosure before performing a compression process along the cross-sectional line B-B' of FIG. 1, FIG. 9 is a cross-sectional view showing the state of a basic unit cell (10b) of a second type of all-solid-state battery according to another embodiment of the present disclosure after performing a compression process along the cross-sectional line B-B' of FIG. 1, FIG. 10 is a cross-sectional view showing the state of a basic unit cell (10c) of a third type of all-solid-state battery according to yet another embodiment of the present disclosure before performing a compression process along the cross-sectional line B-B' of FIG. 1, and FIG. 11 is a cross-sectional view showing the state of a basic unit cell (10c) of a third type of all-solid-state battery according to yet another embodiment of the present disclosure after performing a compression process along the cross-sectional line B-B' of FIG. 1.

[0087] Referring together to FIGS. 8 to 11 and FIGS. 4 to 5, the basic unit cell (10) of the all-solid-state battery of the present disclosure can be formed in various types. The basic unit cell (10a) shown in FIGS. 4 to 5 may be a first type, the basic unit cell (10b) shown in FIGS. 8 to 9 may be a second type, and the basic unit cell (10c) shown in FIGS. 10 to 11 may be a third type.

[0088] The basic unit cell (10b) of the second type can be stacked in a form where the upper and lower parts are symmetrical with respect to the negative current collector (400). That is, the negative electrode (300), solid electrolyte (500), film assembly (600a, 600b), positive electrode (100), insulating member (220), and positive current collector (200) can be provided in multiple numbers and stacked so as to be symmetrical with respect to the negative current collector (400). The negative electrode (300), solid electrolyte (500), positive electrode (100), and positive current collector (200) can be stacked in order downwards with respect to the negative current collector (400), and the negative electrode (300), solid electrolyte (500), positive electrode (100), and positive current collector (200) can be stacked in order upwards with respect to the negative current collector (400). The second type of basic unit cell (10b) may include one negative current collector (400) and two positive current collectors (200), with the negative current collector (400) located in the center and the positive current collectors (200) located on each side of the basic unit cell (10b).

[0089] At this time, the basic unit cell (10b) of the second type of all-solid-state battery may further include a third film layer (700). The third film layer (700) may be disposed on the outside of the positive current collector (200). The third film layer (700) may be composed of a third film (701) containing an insulating material and a third adhesive layer (702) that bonds two adjacent layers containing the third film (701). At this time, when stacking a plurality of basic unit cells (10b) of all-solid-state batteries, the third adhesive layer (702) may bond the third film (701) to the outer surface of an adjacent basic unit cell (10b). The third film layer (700) may be formed with a structure similar to that of the second film layer (620). The third film layer (700) may include an insulating receiving portion (630) that accommodates at least a portion of the insulating member (220). However, the third film layer (700) may not have a positive electrode receiving portion (640) formed therein for receiving the positive electrode (100). The third film layer (700) may form a layer identical to at least one of the plurality of insulating members (220). For example, it may form a layer identical to the insulating member (220) located at the outermost position relative to the basic unit cell (10c) of the second type of all-solid-state battery.

[0090] The third type of basic unit cell (10c) may be configured such that the positive electrode (100) is positioned relative to the positive electrode current collector (200), while the negative electrode (300) is positioned only on one side. The film assembly, the insulating member (220), and the positive electrode (100) may each be provided in multiple numbers and stacked to be symmetrical relative to the positive electrode current collector (200). Additionally, the solid electrolyte (500) and the negative electrode (300) may each be provided in multiple numbers and stacked to be symmetrical relative to the negative electrode current collector (400). Furthermore, at least one of the solid electrolytes (500) may be stacked to face at least one of the negative electrodes (300). For example, the positive electrode (100) may be stacked on the upper and lower sides relative to the positive electrode current collector (200). A solid electrolyte (500), a cathode (300), a cathode current collector (400), a cathode (300), and a solid electrolyte (500) can be stacked in the order of on the outside of either the upper or lower anode (100).

[0091] In addition to the basic unit cell (10) of the first to third types described above, various forms of basic unit cell (10) structures can be formed, so it is not necessarily limited to the basic unit cell (10) of the first to third types.

[0092] The basic unit cell (10) of the second and third types can also be formed by extending the first film layer (610) and the second film layer (620) to the end of the electrode tab to fill the empty space (E) as in FIG. 2, and then proceeding with the compression step (S500). Although a gap (G) may be formed as in FIG. 8 and FIG. 10, the gap (G) can be filled with a release liner (800) as described above, and since the formed gap (G) is not large enough to accommodate a pouch (P), the problem of a broken wire (C) of the electrode tab as in FIG. 3 can be prevented.

[0093] The method of manufacturing the basic unit cell (10) of the second or third type can be appropriately modified in FIG. 6, and the removal area (R) shown after the compression step (S500) is performed can be removed.

[0094] For example, referring together with FIG. 6, in manufacturing a basic unit cell (10b) of a second type of all-solid-state battery, the assembly step (S400) may include the step of stacking a third film layer (700) on the outside of a positive current collector (200).

[0095] Referring to FIG. 5 and 7, an all-solid-state battery according to one embodiment of the present disclosure may include the above-described positive electrode (100), solid electrolyte (500), negative electrode (300), positive current collector (200), and negative current collector (400).

[0096] An all-solid-state battery according to one embodiment of the present disclosure may include a film assembly. The film assembly referred to herein may be the secondary film assembly (600b) described above.

[0097] According to one embodiment of the present disclosure, at least one region of the side of the film assembly of the all-solid-state battery may be recessed. For example, at least one region of the side of the film assembly may be recessed along the aforementioned pre-removal line (650) in a direction opposite to the protruding direction of the positive tab (210) or negative tab (410).

[0098] An all-solid-state battery according to one embodiment of the present disclosure can be manufactured by various methods in addition to the all-solid-state battery manufacturing method described above.

[0099] Although the present disclosure has been illustrated and described in connection with preferred embodiments to illustrate the principles of the present disclosure, the present disclosure is not limited to the configuration and operation as illustrated and described. Rather, those skilled in the art will understand that numerous changes and modifications to the present disclosure are possible without departing from the spirit and scope of the appended claims.

Claims

1. A first punching step of punching at least a portion of a second film layer containing an insulating material to form an insulating receiving portion for receiving an insulating member; A bonding step of bonding the second film layer to a first film layer comprising an insulating material; A second punching step of punching the first film layer and the second film layer together to form an anode receiving portion and a pre-removal line in the first film assembly; An assembly step of laminating an anode, an anode current collector, a solid electrolyte, a cathode, and a cathode current collector onto the primary film assembly; and A method for manufacturing an all-solid-state battery, comprising: a cutting step of forming a secondary film assembly by cutting a portion of the primary film assembly along a cutting line connected to the above-mentioned pre-removal line.

2. In Paragraph 1, The above positive current collector includes a positive tab protruding to one side, and The insulating member surrounds at least a portion of the positive tab, and A method for manufacturing an all-solid-state battery, wherein the width and length of the insulating receiving portion formed in the first punching step are equal to or greater than the width and length of the insulating member.

3. In Paragraph 1, The second film layer comprises a second film including an insulating material and a second adhesive layer that bonds two adjacent layers including the second film. A method for manufacturing an all-solid-state battery, wherein the bonding step is a step of bonding the second film and the first film layer with a second bonding layer.

4. In Paragraph 1, The pre-removal line formed in the above second punching step includes a first line and a second line, and The above first line is spaced apart from the edge line, and The above edge line is formed on at least one of the one edge of the positive current collector having a protruding positive tab and the one edge of the negative current collector having a protruding negative tab, and A method for manufacturing an all-solid-state battery, wherein one end of the second line is connected to each end of the first line.

5. In Paragraph 4, A method for manufacturing an all-solid-state battery, wherein the first line is formed parallel to the edge line.

6. In Paragraph 4, The above second line is, Inclined with the above first line, A method for manufacturing an all-solid-state battery in which the other end is spaced apart from the edge line above the first line above.

7. In Paragraph 4, A method for manufacturing an all-solid-state battery, wherein the cutting line starts from the other end of the second line and is spaced apart from the edge line.

8. In Paragraph 1, A method for manufacturing an all-solid-state battery, wherein the assembly step comprises stacking the positive current collector, the positive electrode, the solid electrolyte, the negative electrode, and the negative current collector in order, and accommodating the positive electrode and the insulating member in the positive electrode receiving portion and the insulating receiving portion, respectively.

9. In Paragraph 1, A method for manufacturing an all-solid-state battery, wherein the assembly step comprises the step of laminating a third film layer on the outer side of the positive current collector.

10. In Paragraph 9, A method for manufacturing an all-solid-state battery comprising: a third film layer comprising an insulating material and a third adhesive layer that bonds two adjacent layers including the third film, and an insulating receiving portion.

11. In Paragraph 9, A method for manufacturing an all-solid-state battery, wherein the assembly step is a step of adhering a release liner to at least one of the first film layer and the second film layer.

12. In Paragraph 11, A method for manufacturing an all-solid-state battery, wherein the above cutting step includes the step of removing the release liner together.

13. In Paragraph 1, A method for manufacturing an all-solid-state battery, further comprising a compression step of pre-packaging a structure formed in the assembly step into a pouch and then compressing it.

14. In Paragraph 1, A method for manufacturing an all-solid-state battery, further comprising: an electrical connection step of electrically connecting each of a plurality of structures formed in the cutting step above after stacking them.

15. In Paragraph 14, A method for manufacturing an all-solid-state battery, further comprising a packaging step for packaging a structure formed in the electrical connection step above.

16. Anode, solid electrolyte, and cathode sequentially stacked in the stacking direction; A positive current collector that is laminated on one surface of the positive electrode and electrically connected to the positive electrode, and includes a positive electrode tab protruding to one side; A cathode current collector laminated on one surface of the cathode and electrically connected to the cathode, and including a cathode tab protruding to one side; and A film assembly provided in the same layer as the anode and surrounding the perimeter of the anode; A solid-state battery comprising, wherein at least one region of the side of the film assembly is recessed along a pre-removal line in a direction opposite to the protruding direction of the positive tab or the negative tab.

17. In Paragraph 16, A solid-state battery in which the above-mentioned pre-removal line is arranged such that at least a portion overlaps with the positive tab or the negative tab in the stacking direction.

18. In Paragraph 16, The above-mentioned pre-removal line includes a first line and a second line, and The first line is spaced apart from the edge line of one side of the positive current collector with the protruding positive tab or one side of the negative current collector with the protruding negative tab, The above second line is a solid-state battery, one end of which is connected to the above first line.

19. In Paragraph 18, A solid-state battery in which the first line is arranged to overlap with the positive tab or the negative tab in the stacking direction.

20. In Paragraph 18, The above-mentioned first line is located closer to the edge line than the above-mentioned second line, in an all-solid-state battery.

Images