Electrolyte Storage Apparatus and method for manufacturing the same

Abstract

The present invention relates to an electrolyte storage device and a method for manufacturing the same, wherein the electrolyte storage device is configured to prevent the electrolyte from adhering by forming a fine pattern inside the device to increase the hydrophobicity of the surface.

Description

Technology Field

[0001] The present invention relates to an electrolyte storage device and a method for manufacturing the same, wherein the electrolyte storage device is configured to prevent the electrolyte from adhering by forming a fine pattern inside the device to increase the hydrophobicity of the surface. Background Technology

[0003] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries capable of both charging and discharging. Low-capacity secondary batteries are used in small portable electronic devices such as smartphones, feature phones, laptop computers, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources for motor drive systems and power storage batteries in hybrid and electric vehicles. A secondary battery includes an electrode assembly having a positive electrode and a negative electrode, a case housing the electrode assembly, and electrode terminals connected to the electrode assembly.

[0004] The conventional secondary battery manufacturing process consists of production through individual processes using automated facilities. During this manufacturing process, the process of injecting the electrolyte, a key component of the secondary battery, is performed.

[0005] In particular, the electrolyte injection process for a secondary battery with a cylindrical shape is performed as follows. The cylindrical secondary battery is loaded onto a tray-type component called a 'Carrier' to perform the electrolyte injection process. Although a cylindrical secondary battery is used as a representative example in this specification, it is not limited to any specific battery shape. The Carrier is a device that stores the electrolyte and injects it into the secondary battery. In particular, the electrolyte is maintained in a stored state in a special component called a Hopper, which is one of the components of the Carrier, and is configured to be injected into the secondary battery. This process is configured such that after creating a vacuum inside the secondary battery, the electrolyte stored in the Hopper at atmospheric pressure naturally flows into the secondary battery through the difference between atmospheric pressure and the vacuum pressure inside the Hopper.

[0006] However, despite the difference in vacuum pressure, electrolytes that were not injected into the secondary battery remain adhering due to adhesion on the inner surface of the hopper. This residual electrolyte leads to an insufficient electrolyte content within the secondary battery, which can negatively affect its performance and quality. Furthermore, it causes contamination of the hopper for special components, acting as a cause that undermines the consistency of the electrolyte injection process.

[0007] The information described above disclosed in the background technology of this invention is intended only to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art. The problem to be solved

[0009] The problem to be solved by the present invention is to provide an electrolyte storage device configured to prevent the electrolyte from adhering by forming a micro-pattern inside to increase the hydrophobicity of the surface in order to solve the above-mentioned problem, and a method for manufacturing the same.

[0010] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems can be clearly understood by those skilled in the art from the description of the invention below. means of solving the problem

[0012] One embodiment of the present invention may provide an electrolyte storage device comprising: an electrolyte housing configured to store an electrolyte; and an inlet located on one surface of the electrolyte housing configured to inject the electrolyte into a secondary battery, wherein the electrolyte housing comprises a pattern in which a three-dimensional structure is continuously formed on its inner surface.

[0013] In one embodiment, the structure may be configured in the shape of a circle, triangle, square, pentagon, or hexagon.

[0014] In one embodiment, the structure may have a height of 40 to 60 μm.

[0015] In one embodiment, the structure may have a diameter or a side length of 180 to 220 μm.

[0016] In one embodiment, the spacing between the structures in the pattern may be 80 μm to 120 μm.

[0017] In one embodiment, the inner surface on which the pattern is formed may be formed by heating a resin comprising any one of polypropylene, polyethylene, polystyrene, polyamide, and polyethylene terephthalate applied to a plate on which the intaglio of the pattern is formed.

[0018] In one embodiment, the pattern may be created by pressing a mold shaft having an intaglio of the pattern formed thereon onto the inner surface.

[0019] In one embodiment, a first pattern may be formed in a first region of the inner surface, and a second pattern including a structure different from the first pattern may be formed in a second region of the inner surface.

[0020] In one embodiment, the pattern may be formed on an area of ​​70% or more of the inner surface.

[0021] In one embodiment, the pattern may be formed such that the static contact angle of the structure is 110 degrees or more.

[0022] In one embodiment, the pattern may be formed such that the area density of the structure is 0.3 or higher.

[0023] One embodiment of the present invention provides a method for manufacturing an electrolyte storage device configured to store an electrolyte and inject the electrolyte into a secondary battery, comprising the steps of: providing a plate; generating an intaglio pattern in which a three-dimensional structure is continuously formed on one surface of the plate using a laser; applying a material of a surface layer to one surface of the plate; heating the material of the surface layer; separating the solidified surface layer from the plate; and attaching the solidified surface layer to the inner surface of the electrolyte storage device.

[0024] One embodiment of the present invention provides a method for manufacturing an electrolyte storage device configured to store an electrolyte and inject the electrolyte into a secondary battery, comprising the steps of: providing a mold shaft; using a laser to create an intaglio pattern in which a three-dimensional structure is continuously formed on the outer surface of the mold shaft; cutting the mold shaft at equal intervals; inserting the cut mold shaft into the interior of the electrolyte storage device; pressing the cut mold shaft onto the inner surface of the electrolyte storage device; and removing the mold shaft from the electrolyte storage device. Effects of the invention

[0026] According to one embodiment of the present invention, a pattern can be efficiently formed on the inner surface of an electrolyte storage device through a laser texturing technique.

[0027] In addition, according to one embodiment of the present invention, the hydrophobicity of the inner surface of the patterned electrolyte storage device is improved, and the adhesive strength of the surface is reduced.

[0028] In addition, according to one embodiment of the present invention, there is an effect of reducing the phenomenon of non-injection of electrolyte that cannot be injected into the secondary electrode due to surface adhesion.

[0029] In addition, according to one embodiment of the present invention, there is an effect of preventing the degradation of battery performance and quality that may occur due to insufficient electrolyte content inside the secondary battery.

[0030] In addition, according to one embodiment of the present invention, there is an effect of preventing contamination that may occur due to residual electrolyte remaining in the electrolyte storage device and maintaining consistency in the electrolyte injection process.

[0031] However, the effects obtainable through the present invention are not limited to those described above, and other unmentioned technical effects will be clearly understood by those skilled in the art from the description of the invention below. Brief explanation of the drawing

[0033] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a drawing illustrating a carrier according to one embodiment of the present invention. FIG. 2 is a drawing illustrating an electrolyte storage device according to one embodiment of the present invention. FIG. 3 is a drawing showing a pattern formed on the inner surface of an electrolyte storage device according to one embodiment of the present invention. FIG. 4 is a flowchart of a pattern formation method according to a first embodiment of the present invention. FIG. 5 is a drawing for explaining a pattern forming method according to a first embodiment of the present invention. FIG. 6 is a flowchart of a pattern formation method according to a second embodiment of the present invention. FIG. 7 is a drawing for explaining a pattern forming method according to a second embodiment of the present invention. FIGS. 8 to 12 are drawings for illustrating a pattern according to an embodiment of the present invention. FIGS. 13 and 14 are drawings for explaining static contact angles by pattern according to an embodiment of the present invention. Specific details for implementing the invention

[0034] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe their invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. It should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0035] Additionally, as used herein, “comprise, include” and / or “comprising, including” specify the presence of the mentioned features, numbers, steps, actions, parts, elements, and / or groups thereof, and do not exclude the presence or addition of one or more other features, numbers, actions, parts, elements, and / or groups.

[0036] Additionally, to aid in understanding the invention, the attached drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. Furthermore, the same reference numerals may be assigned to identical components in different embodiments.

[0037] The statement that two subjects of comparison are 'identical' means that they are 'substantially identical.' Therefore, substantial identity may include deviations considered low in the industry, for example, deviations within 5%. Additionally, the statement that a parameter is uniform in a given area may mean that it is uniform from an average perspective.

[0038] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0039] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0040] The fact that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0041] Furthermore, where one component is described as being "on," "connected to," or "coupled to" another component, it should be understood that while the components may be directly connected or coupled to each other, another component may be "interposed" between each component, or that each component may be "connected," "coupled," or "coupled" through another component.

[0042] As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. Additionally, the use of “may” when describing embodiments of the invention relates to “one or more embodiments of the invention.” Expressions such as “one or more” and “one or more” preceding a list of elements modify the entire list of elements and do not modify individual elements of the list.

[0043] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise, and "C to D" means C or more and D or less, unless specifically stated otherwise.

[0044] When syntax such as "at least one of A, B, and C", "at least one of A, B, or C", "at least one selected from the group of A, B, and C", or "at least one selected from A, B, and C" is used to specify a list of elements A, B, and C, the syntax can refer to any suitable combination.

[0045] The term "use" may be considered synonymous with the term "utilize." As used herein, terms such as "substantially," "about," and similar terms are used as terms of approximation rather than degree, and are intended to account for the inherent variation of a measured or calculated value that would be recognized by a person skilled in the art.

[0046] In this specification, terms such as first, second, third, etc. may be used to describe various elements, components, regions, layers, and / or sections, but these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section. Accordingly, the first element, component, region, layer, or section discussed below may be named the second element, component, region, layer, or section without departing from the teachings of the exemplary embodiments.

[0047] Spatial relative terms such as "beneath," "below," "lower," "above," and "upper" may be used in the specification for ease of description to explain the relationship between one element or feature and other element(s) or feature(s) as illustrated in the drawings. Spatially relative positions are to be understood as encompassing different orientations of the device in use or operation, in addition to the orientations depicted in the figures. For example, if the device in the drawing is inverted, the other element is understood as "below" or "below," and the described element is understood as "above" or "upper" of the other element. Thus, the term "below" may encompass both the up and down directions.

[0048] The terms used in this specification are for describing embodiments of the invention and are not intended to limit the invention.

[0049] The present invention will be described in detail below with reference to the attached drawings.

[0051] FIG. 1 is a drawing illustrating a carrier (10) according to one embodiment of the present invention.

[0052] Referring to FIG. 1, a carrier (10) according to one embodiment of the present invention may be configured to include a plurality of electrolyte storage devices (100).

[0053] The manufacturing process of the secondary battery (20) may include a process of injecting an electrolyte (30), which is a core component of the secondary battery (20), into the secondary battery (20). In particular, in the process of injecting the electrolyte (30) of a secondary battery (20) having a cylindrical shape, the process of injecting the electrolyte (30) may be performed using a carrier (10). The exterior of the secondary battery (20) may be configured in various shapes such as circular, prismatic, or pouch, and is not limited thereto. FIGS. 1 to 3 illustrate a carrier and a hopper of a cylindrical secondary battery, but are not limited thereto.

[0054] The carrier (10) is a tray-type device, and the carrier (10) may be loaded with a plurality of secondary batteries (20) and may include a plurality of electrolyte storage devices (100) in which electrolyte (30) is stored. For example, as shown in the drawing, the carrier (10) may be configured to allow loading of 12x12, that is, 144 secondary batteries (20).

[0055] The electrolyte storage device (100) stores the electrolyte (30) and can be configured to inject the electrolyte (30) into the interior of the secondary battery (20). The electrolyte storage device (100) may include a conventional hopper.

[0056] The electrolyte storage device (100) can inject the electrolyte (30) into the interior of the secondary battery (20) through various methods. For example, the electrolyte storage device (100) can be configured such that after creating a vacuum inside the secondary battery (20), the electrolyte (30) stored in the electrolyte storage device (100) at atmospheric pressure naturally flows into the interior of the secondary battery (20) through the difference between atmospheric pressure and the vacuum pressure inside the electrolyte storage device (100).

[0057] However, in this case, despite the difference in vacuum pressure, the electrolyte (30) that was not injected into the secondary battery (20) may remain attached due to the adhesion present on the inner surface of the electrolyte storage device (100). This residual electrolyte (30) may cause a shortage of electrolyte content inside the secondary battery (20), which may have a negative effect on the performance and quality of the secondary battery (20). Furthermore, it may cause contamination of the electrolyte storage device (100), thereby hindering the consistency of the electrolyte (30) injection process.

[0058] The present invention relates to an electrolyte storage device (100) configured to form a fine pattern inside the electrolyte storage device to increase the hydrophobicity of the surface so that the electrolyte does not adhere, and a method for manufacturing the same.

[0060] FIG. 2 is a drawing illustrating an electrolyte storage device (100) according to one embodiment of the present invention, and

[0061] Referring to FIG. (a), the electrolyte storage device (100) may include an electrolyte housing capable of storing an electrolyte (30). The electrolyte storage device (100) of the drawing includes a cylindrical electrolyte housing (30), but the shape of the electrolyte housing is not limited thereto and can be configured in various shapes.

[0062] The electrolyte storage device (100) may include an inlet capable of injecting the stored electrolyte (30) into the secondary battery (20), and the inlet is located on one side of the electrolyte housing and may be configured as a circular inlet as shown in the drawing. However, the shape of the inlet may be configured differently depending on the opening / closing part of the secondary battery or the injection method. The inlet according to one embodiment of the present invention is configured to be openable and closable, so that it can be operated to open only when the injection of the electrolyte (30) is required.

[0063] FIGS. (b) and FIGS. (c) illustrate an internal cross-section of an electrolyte storage device (100) in one direction. Referring to FIGS. (b) and FIGS. (c), a pattern (110) of a certain shape is formed on the internal surface of the electrolyte storage device (100). Specifically, the pattern (110) may be formed on the internal surface of the electrolyte housing of the electrolyte storage device (100). Hereinafter, the internal surface of the electrolyte storage device (100) refers to the surface of the electrolyte housing of the electrolyte storage device (100).

[0064] A pattern (110) according to one embodiment of the present invention may mean that a three-dimensional structure of a certain shape is continuously formed.

[0065] A pattern (110) may be formed in a certain area of ​​the inner surface of the electrolyte storage device (100). The pattern (110) may be formed on all inner surfaces of the electrolyte housing, or the pattern (110) may be formed only on a specific inner surface of the electrolyte housing.

[0067] FIG. 3 is a drawing showing a pattern (110) formed on the inner surface of an electrolyte storage device (100) according to one embodiment of the present invention.

[0068] Referring to FIG. 3, a pattern (110) is formed on the inner surface of an electrolyte storage device (100) according to one embodiment of the present invention, and as described above, the pattern (110) may mean that a three-dimensional structure of a certain shape is continuously formed.

[0069] Although the drawing shows a pattern (110) including a structure in the shape of an equilateral triangle, the pattern (110) according to one embodiment of the present invention may include a three-dimensional structure composed of various shapes and sizes, and may be configured to include a three-dimensional structure of an optimal shape and size that can improve the hydrophobicity of the inner surface of the electrolyte storage device (100) and reduce adhesive strength.

[0070] And although the drawing shows a two-dimensional equilateral triangle pattern, the pattern (110) according to one embodiment of the present invention may include a three-dimensional structure having a certain height on the inner surface.

[0071] A pattern (110) according to one embodiment of the present invention may be composed of a series of structures in the shape of a circle, triangle, square, pentagon, or hexagon, and for example, the pattern (110) may be composed of a series of structures in the shape of a circle, equilateral triangle, square, regular pentagon, or regular hexagon. The height of the structures of the pattern (110) may be composed of 40 to 60 μm, and the diameter or length of one side (100b) of the structures of the pattern (110) may be composed of 180 to 220 μm. Also, the spacing (100a) between the structures of the pattern (110) may be composed of 80 μm to 120 μm.

[0072] Additionally, a pattern (110) according to one embodiment of the present invention may include a structure configured in a different shape. For example, the upper inner surface of the electrolyte storage device (100) may be formed with a pattern (110) including a triangular structure, and the lower surface may be formed with a pattern (110) including a pentagonal structure.

[0073] Additionally, a pattern (110) according to one embodiment of the present invention may include structures configured with different sizes and spacing. For example, on the upper surface of the electrolyte storage device (100), the structure height may be 40 μm and the diameter or length of one side may be 180 μm, and on the upper surface of the electrolyte storage device (100), the structure height may be 60 μm and the diameter or length of one side may be 220 μm. Furthermore, a pattern (110) may be formed such that the spacing between the structures becomes closer as it extends toward the upper surface of the electrolyte storage device (100).

[0074] That is, a first pattern (110) is formed in a first region of the inner surface of the electrolyte storage device (100), and a second pattern (110) including a structure different from the first pattern can be formed in a second region of the inner surface of the electrolyte storage device (100).

[0076] Hereinafter, a method for forming a pattern (110) on the inner surface of an electrolyte storage device (100) will be described. The method for forming a pattern (110) on the inner surface of an electrolyte storage device (100) may be part of a method for manufacturing an electrolyte storage device (100).

[0077] FIG. 4 is a flowchart of a pattern forming method according to a first embodiment of the present invention, and FIG. 5 is a drawing for explaining a pattern forming method according to a first embodiment of the present invention.

[0078] First, referring to FIG. 4, a pattern forming method according to the first embodiment of the present invention may include steps S100 to S140.

[0079] Step S100 is a step of providing a plate. The plate may be composed of a material similar to the material of the mold used in the process of manufacturing the electrolyte storage device (100), and for example, the plate may be composed of a material including any one of stainless steel, stainless steel alloy, titanium alloy, nickel alloy, and carbon fiber. For example, SUS304 may be used in the stainless steel series.

[0080] Step S110 is a step of forming a pattern (110) on one surface of a plate using a laser. An intaglio of the pattern (110) is formed on one surface of the plate using a laser. The laser may be a nano-second, femto-second, pico-second laser, etc., and the pattern (110) on one surface of the plate may be formed using a laser texturing technique. For example, the conditions for laser texturing can be set by adjusting the frequency, output, scanning speed, or number of cycles. For example, the scanning frequency may be in the range of 17 to 23 kHz. The output may be 1.8 to 2.2 W. The scanning speed may be 0.5 to 1.5 mm / s. The number of cycles may be 3 to 8 cycles.

[0081] Step S120 is a step of applying a surface layer material to one side of a plate on which a pattern (110) is formed. The surface layer refers to a layer that forms the inner surface of an electrolyte storage device (100), and the surface layer material may be a resin containing any one of polypropylene, polyethylene, polystyrene, polyamide, and polyethylene terephthalate.

[0082] Step S130 is a step of heating the surface layer material applied to one side of the plate. For example, the surface layer material applied to one side of the plate is 200 It can be heated for 30 minutes using a heat source, and due to the heating, the surface layer material can form a solidified surface layer. Since the pattern (110) is engraved on the plate, the pattern (110) of the plate can be imitated and formed on the surface layer. That is, the pattern of the plate is imitated and formed on the surface layer through a molding technique.

[0083] Step S140 is a step of separating the surface layer on which the pattern (110) is formed. By separating the solidified surface layer from the plate, the surface layer on which the pattern (110) is formed can be obtained.

[0084] Subsequently, the inner surface of the electrolyte storage device (100) can be manufactured using the surface layer on which the pattern (110) is formed. For example, the step of attaching the surface layer on which the pattern (110) is formed to the inner surface of the electrolyte storage device (100) may be further included.

[0085] And with reference to FIG. 5, a pattern forming method according to the first embodiment of the present invention described above is illustrated, and the pattern forming method according to the first embodiment of the present invention may be composed of the steps of: (i) providing a plate and forming an intaglio of a pattern (110) on one surface of the plate using a laser; (ii) applying a surface layer material to one surface of the plate on which the pattern (110) is formed; (iii) heating the surface layer material applied to the plate; and (iv) separating the surface layer on which the pattern (110) is formed.

[0086] According to the pattern forming method of the first embodiment of the present invention, a pattern (110) can be efficiently formed on the inner surface of an electrolyte storage device (100). In particular, by utilizing a laser texturing technique, a pattern (110) with a large area can be produced in a short period of time, and the pattern (110) can be formed using only physical processes without chemical processes. In addition, there is an advantage that the pattern (110) can be formed in a short period of time on the surface of a polymer material other than polypropylene.

[0088] FIG. 6 is a flowchart of a pattern forming method according to a second embodiment of the present invention, and FIG. 7 is a drawing for explaining a pattern forming method according to a second embodiment of the present invention.

[0089] First, referring to FIG. 6, a pattern forming method according to a second embodiment of the present invention may include steps S200 to S250.

[0090] Step S200 is a step of providing a mold shaft. The mold shaft may be composed of a material similar to the material of the mold used in the process of manufacturing the electrolyte storage device (100), and for example, the mold shaft may be composed of a material including any one of stainless steel, stainless alloy, titanium alloy, nickel alloy, and carbon fiber. For example, SUS304 may be used in the stainless steel series.

[0091] Step S210 is a step of forming a pattern (110) on the outer surface of a mold shaft using a laser. This involves forming an intaglio of the pattern (110) on the outer surface of the mold shaft using a laser. A nano-second laser may be used, and the pattern (110) may be formed on the mold shaft using a laser texturing technique. For example, the conditions for laser texturing can be set by adjusting the frequency, output, scanning speed, or number of cycles. For example, the scanning frequency may be in the range of 17 to 23 kHz. The output may be 1.8 to 2.2 W. The scanning speed may be 0.5 to 1.5 mm / s. The number of cycles may be 3 to 8 cycles.

[0092] Step S220 is a step of cutting the mold shaft on which the pattern (110) is formed. The mold shaft on which the pattern (110) is formed is cut at equal intervals along the length direction. For example, the mold shaft on which the pattern (110) is formed can be divided into 4 to 8 equal intervals, and the pattern (110) formed on the outer surface can be not cut.

[0093] Step S230 is the step of inserting the cut mold shaft into the interior of the electrolyte storage device (100). The cut mold shaft is inserted into the interior of the electrolyte storage device (100) at the location where the pattern (110) is to be formed.

[0094] Step S240 is a step of pressing the inserted mold shaft onto the inner surface of the electrolyte storage device (100). Since a pattern (110) is formed on the outer surface of the mold shaft, the pattern (110) of the mold shaft can be imitated and formed on the inner surface of the electrolyte storage device (100). Since the mold shaft is cut at equal intervals, gaps may occur between the mold shafts being pressed, and the gaps between the mold shafts being pressed can be configured to be equal to the gaps of the pattern (110).

[0095] Step S250 is the step of removing the mold shaft from the electrolyte storage device (100).

[0096] And with reference to FIG. 7, a pattern forming method according to the second embodiment of the present invention described above is illustrated, and the pattern forming method according to the second embodiment of the present invention may be composed of: (i) a step of forming a pattern (110) on the outer surface of the mold shaft using a laser, (ii) a step of cutting the mold shaft with the pattern (110) formed thereon at equal intervals, (iii) a step of inserting the cut mold shaft into the interior of an electrolyte storage device (100) and pressing it, and (iv) a step of removing the mold shaft from the electrolyte storage device (100).

[0097] According to the pattern forming method according to the second embodiment of the present invention, the shape of the pattern (110) desired by the user can be freely designed, and the shape of the pattern (110) can be adjusted according to the purpose, thereby enabling flexible design at the nano or micro scale.

[0099] The pattern forming method according to the first and second embodiments of the present invention described above has been explained with reference to the flowchart presented in the drawings. For simplicity of explanation, the method has been illustrated and described in a series of blocks; however, the present invention is not limited to the order of said blocks, and some blocks may occur in a different order or simultaneously with other blocks as illustrated and described herein, and various other branches, flow paths, and sequences of blocks that achieve the same or similar results may be implemented. Furthermore, not all illustrated blocks may be required for the implementation of the method described herein.

[0100] Meanwhile, in the description with reference to FIGS. 4 and FIGS. 6, each step may be further divided into additional steps or combined into fewer steps, depending on an embodiment of the present invention. Additionally, some steps may be omitted as necessary, and the order between steps may be changed.

[0102] FIGS. 8 to 12 are drawings for explaining a pattern (110) according to an embodiment of the present invention.

[0103] As described above, a pattern (110) can be formed on the inner surface of an electrolyte storage device (100) using the pattern forming method of the first and second embodiments of the present invention. After the pattern (110) is formed on the inner surface of the electrolyte storage device (100), the shape and size of the formed pattern (110) can be verified using a 3D laser confocal microscope and a scanning electron microscope (SEM).

[0104] A pattern (110) according to one embodiment of the present invention may include a three-dimensional structure composed of various shapes and sizes, and may be configured to include a three-dimensional structure of an optimal shape and size that can improve hydrophobicity of the inner surface of the electrolyte storage device (100) and reduce adhesive strength.

[0106] FIG. 8 is a drawing for explaining a pattern (110) according to a first embodiment of the present invention, and the pattern (110) according to the first embodiment of the present invention may be configured to include a circular three-dimensional structure as a circular pattern (110).

[0107] FIG. (a) is an image illustrating an example of the size of a circular structure according to the first embodiment of the present invention, FIG. (b) is an image of a circular pattern (110) according to the first embodiment of the present invention confirmed through a 3D laser confocal microscope, and FIG. (c) is an image of a circular pattern (110) according to the first embodiment of the present invention confirmed using a scanning electron microscope (SEM).

[0109] FIG. 9 is a drawing for explaining a pattern (110) according to a second embodiment of the present invention, and the pattern (110) according to the second embodiment of the present invention may be configured to include a three-dimensional structure in the shape of an equilateral triangle as an equilateral triangle pattern (110).

[0110] FIG. (a) is an image illustrating an example of the size of an equilateral triangle structure according to a second embodiment of the present invention, FIG. (b) is an image of an equilateral triangle pattern (110) according to a second embodiment of the present invention confirmed through a 3D laser confocal microscope, and FIG. (c) is an image of an equilateral triangle pattern (110) according to a second embodiment of the present invention confirmed using a scanning electron microscope (SEM).

[0112] FIG. 10 is a drawing for explaining a pattern (110) according to a third embodiment of the present invention, and the pattern (110) according to the third embodiment of the present invention may be configured to include a square-shaped three-dimensional structure as a square pattern (110).

[0113] FIG. (a) is an image illustrating an example of the size of a square structure according to the third embodiment of the present invention, FIG. (b) is an image of a square pattern (110) according to the third embodiment of the present invention confirmed through a 3D laser confocal microscope, and FIG. (c) is an image of a square pattern (110) according to the third embodiment of the present invention confirmed using a scanning electron microscope (SEM).

[0115] FIG. 11 is a drawing for explaining a pattern (110) according to a fourth embodiment of the present invention, and the pattern (110) according to the fourth embodiment of the present invention may be configured to include a three-dimensional structure in the shape of a regular pentagon as a regular pentagon pattern (110).

[0116] FIG. (a) is an image illustrating an example of the size of a regular pentagon structure according to the fourth embodiment of the present invention, FIG. (b) is an image of a regular pentagon pattern (110) according to the fourth embodiment of the present invention confirmed through a 3D laser confocal microscope, and FIG. (c) is an image of a regular pentagon pattern (110) according to the fourth embodiment of the present invention confirmed using a scanning electron microscope (SEM).

[0118] FIG. 12 is a drawing for explaining a pattern (110) according to a fifth embodiment of the present invention, and the pattern (110) according to the fifth embodiment of the present invention may be configured to include a three-dimensional structure in the shape of a regular hexagon as a regular hexagon pattern (110).

[0119] FIG. (a) is an image illustrating an example of the size of a regular hexagonal structure according to the fifth embodiment of the present invention, FIG. (b) is an image of a regular hexagonal pattern (110) according to the fifth embodiment of the present invention confirmed through a 3D laser confocal microscope, and FIG. (c) is an image of a regular hexagonal pattern (110) according to the fifth embodiment of the present invention confirmed using a scanning electron microscope (SEM).

[0121] The pattern (110) according to the first to fifth embodiments of the present invention described above can increase the static contact angle between the inner surface of the electrolyte storage device (100) and the electrolyte, thereby increasing the hydrophobicity of the surface. Accordingly, the adhesive force of the inner surface of the electrolyte storage device (100) is lowered, which has the effect of reducing the phenomenon of electrolyte non-injection that prevents the electrolyte from being injected into the secondary battery.

[0122] The static contact angle is the angle formed by a liquid on a solid surface. Depending on the static contact angle, the wettability, surface energy, and surface properties regarding water of the solid surface may change. For example, the larger the size of the contact angle, the higher the wettability of the solid surface, the lower the surface energy, and the higher the hydrophobicity. Accordingly, the hydrophobicity of the internal surface can be confirmed by measuring the static contact angle of the internal surface of the electrolyte storage device (100) on which the pattern (110) is formed.

[0123] In the present invention, the static contact angle can be measured using the sessile drop method, for example, by dropping 2 μL of water onto the inner surface of an electrolyte storage device (100) on which a pattern (110) is formed, and then measuring the static contact angle after 10 seconds. In addition, to improve reliability, repeated measurements can be taken at three or more different points.

[0125] FIGS. 13 and 14 are drawings for explaining the static contact angle for each pattern (110) according to one embodiment of the present invention, illustrating the static contact angle for each pattern (110) measured using the aforementioned Sessile drop method.

[0126] Referring to FIGS. 13 and 14, the static contact angle for each pattern (110) measured using the aforementioned Sessile drop method is 146.2° for the circular pattern (110), 148.5° for the equilateral triangle pattern (110), 142.2° for the square pattern (110), 144.9° for the regular pentagon pattern (110), and 146.6° for the regular hexagon pattern (110).

[0127] It can be confirmed that the static contact angle for each pattern (110) is increased compared to the static contact angle (148.5°) in the state without the pattern (110) (Bare). Therefore, the pattern (110) according to the first to fifth embodiments of the present invention described above increases the static contact angle between the inner surface of the electrolyte storage device (100) and the electrolyte (30), and can increase the hydrophobicity of the surface.

[0128] This can be confirmed that the electrolyte (30) in contact with the inner surface of the electrolyte storage device (100) on which the pattern (110) is formed becomes a Cassie-Baxter state, and the hydrophobicity of the surface increases. That is, the micro-sized fine patterns (110) support the electrolyte (30), so that the electrolyte (30) does not fill the cavities between the patterns (110) and remains floating on the surface (Cassie-Baxter state).

[0129] Figure 14 shows the area density for each pattern (110), and the area density is the value obtained by dividing the area of ​​the pattern (110) formed on the electrolyte storage device (100) by the surface area of ​​the electrolyte storage device (100).

[0130] Referring to the drawing, it can be seen that the area density of the structure and the static contact angle show an inversely proportional tendency, and that the smaller the area of ​​the pattern (110) formed on the surface, the greater the hydrophobicity and the greater the area density. This shows the correlation between the area of ​​the pattern (110) and the increase in hydrophobicity.

[0131] Accordingly, in order to increase the hydrophobicity of the surface of the electrolyte storage device (100) above a certain level, the pattern (110) according to one embodiment of the present invention may be formed such that the static contact angle of the aforementioned structure is 110 degrees or more or the area density of the structure is 0.3 or more.

[0133] A material that can be used in a secondary battery according to one embodiment of the present invention is described below.

[0134] As a positive electrode active material, a compound capable of reversible intercalation and deintercalation of lithium (a lithated intercalation compound) may be used. Specifically, one or more composite oxides of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof may be used.

[0135] The above composite oxide may be a lithium transition metal composite oxide, and specific examples include a lithium nickel-based oxide, a lithium cobalt-based oxide, a lithium manganese-based oxide, a lithium iron phosphate-based compound, a cobalt-free nickel-manganese-based oxide, or a combination thereof.

[0136] As an example, a compound represented by any one of the following chemical formulas may be used. Li a A 1-b X b O 2-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Mn 2-b X b O 4-c D c (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.05); Li a Ni1-b-c Co b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni 1-b-c Mn b X c O 2-α D α (0.90≤a≤1.8, 0≤b≤0.5, 0≤c≤0.5, 0<α<2); Li a Ni b Co c L 1 d G e O2(0.90≤a≤1.8, 0≤b≤0.9, 0≤c≤0.5, 0≤d≤0.5, 0≤e≤0.1); Li a NiG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a CoG b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-b G b O2(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn2G b O4(0.90≤a≤1.8, 0.001≤b≤0.1); Li a Mn 1-g G g PO4(0.90≤a≤1.8, 0≤g≤0.5); Li (3-f) Fe2(PO4)3(0≤f≤2); Li a FePO4(0.90≤a≤1.8).

[0137] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; L 1is Mn, Al, or a combination thereof.

[0138] A positive electrode for a lithium secondary battery may include a current collector and a positive electrode active material layer formed on the current collector. The positive electrode active material layer may include a positive electrode active material and may further include a binder and / or a conductive material.

[0139] The content of the positive active material is 90% to 99.5% by weight with respect to 100% by weight of the positive active material layer, and the content of the binder and the conductive material may each be 0.5% to 5% by weight with respect to 100% by weight of the positive active material layer.

[0140] Al may be used for the above-mentioned current collector, but is not limited thereto.

[0141] The negative electrode active material includes a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide.

[0142] A material capable of reversibly intercalating / deintercalating the above lithium ions may be a carbon-based negative electrode active material, such as crystalline carbon, amorphous carbon, or a combination thereof. Examples of the crystalline carbon include graphite, such as natural graphite or artificial graphite, and examples of the amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, etc.

[0143] As a material capable of doping and dedoping the above lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material may be used. The above Si-based negative electrode active material is silicon, a silicon-carbon composite, SiOx (0 <x<2), Si계 합금, 또는 이들의 조합일 수 있다.

[0144] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles.

[0145] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core comprising crystalline carbon and silicon particles and an amorphous carbon coating layer located on the surface of the core.

[0146] A negative electrode for a lithium secondary battery comprises a current collector and a negative electrode active material layer located on the current collector. The negative electrode active material layer comprises a negative electrode active material and may further comprise a binder and / or a conductive material.

[0147] For example, the negative electrode active material layer may comprise 90% to 99% by weight of negative electrode active material, 0.5% to 5% by weight of binder, and 0% to 5% by weight of conductive material.

[0148] As the binder, a non-aqueous binder, an aqueous binder, a dry binder, or a combination thereof may be used. When an aqueous binder is used as the cathode binder, a cellulose-based compound capable of imparting viscosity may be further included.

[0149] As the above-mentioned cathode current collector, a material selected from copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, and combinations thereof may be used.

[0150] The electrolyte for lithium secondary batteries contains a non-aqueous organic solvent and a lithium salt.

[0151] The above-mentioned non-aqueous organic solvent serves as a medium through which ions involved in the electrochemical reaction of the battery can move.

[0152] The above-mentioned non-aqueous organic solvent may be a carbonate-based, ester-based, ether-based, ketone-based, or alcohol-based solvent, a non-protic solvent, or a combination thereof, and may be used alone or in a mixture of two or more types.

[0153] In addition, when using carbonate-based solvents, cyclic carbonates and chain carbonates can be mixed and used.

[0154] Depending on the type of lithium secondary battery, a separator may be present between the positive and negative electrodes. As such a separator, polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer film of two or more layers thereof may be used.

[0155] The above separator may include a porous substrate and a coating layer comprising an organic material, an inorganic material, or a combination thereof located on one or both sides of the porous substrate.

[0156] The above organic material may include a polyvinylidene fluoride-based antibody or a (meth)acrylic-based polymer.

[0157] The above inorganic materials are Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, It may include, but is not limited to, inorganic particles selected from SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof.

[0158] The above organic and inorganic materials may exist mixed in a single coating layer, or may exist in a stacked form with a coating layer containing organic materials and a coating layer containing inorganic materials.

[0160] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs. Explanation of the symbols

[0162] 10: Suitcase 20: Secondary battery 30: Electrolyte 100: Electrolyte storage device 110: Pattern

Claims

Claim 1 An electrolyte storage device comprising: an electrolyte housing configured to store an electrolyte; and an inlet located on one surface of the electrolyte housing and configured to inject the electrolyte into a secondary battery, wherein the electrolyte housing includes a pattern in which a three-dimensional structure is continuously formed on its inner surface. Claim 2 An electrolyte storage device according to claim 1, characterized in that the structure is configured in the shape of a circle, triangle, square, pentagon, or hexagon. Claim 3 An electrolyte storage device according to claim 2, wherein the structure has a height of 40 to 60 μm. Claim 4 An electrolyte storage device according to claim 2, wherein the structure has a diameter or a side length of 180 to 220 μm. Claim 5 An electrolyte storage device according to claim 2, wherein the pattern is characterized in that the spacing between the structures is 80 μm to 120 μm. Claim 6 An electrolyte storage device according to claim 1, wherein the inner surface on which the pattern is formed is formed by heating a resin comprising any one of polypropylene, polyethylene, polystyrene, polyamide, and polyethylene terephthalate applied to a plate on which the intaglio of the pattern is formed. Claim 7 An electrolyte storage device according to claim 1, wherein the pattern is formed by pressing a mold shaft having an intaglio of the pattern onto the inner surface. Claim 8 An electrolyte storage device according to claim 1, characterized in that a first pattern is formed in a first region of the inner surface, and a second pattern including a structure different from the first pattern is formed in a second region of the inner surface. Claim 9 An electrolyte storage device according to claim 1, characterized in that the pattern is formed in an area of ​​70% or more of the inner surface. Claim 10 An electrolyte storage device according to claim 1, characterized in that the pattern is formed such that the static contact angle of the structure is 110 degrees or more. Claim 11 An electrolyte storage device according to claim 1, characterized in that the pattern is formed such that the area density of the structure is 0.3 or higher. Claim 12 A method for manufacturing an electrolyte storage device configured to store an electrolyte and inject the electrolyte into a secondary battery, comprising the steps of: providing a plate; using a laser to create an intaglio pattern in which a three-dimensional structure is continuously formed on one surface of the plate; applying a material of a surface layer to one surface of the plate; heating the material of the surface layer; separating the solidified surface layer from the plate; and attaching the solidified surface layer to the inner surface of the electrolyte storage device. Claim 13 A method for manufacturing an electrolyte storage device according to claim 12, wherein the plate is composed of a material including any one of stainless steel, stainless steel alloy, titanium alloy, nickel alloy, and carbon fiber. Claim 14 A method for manufacturing an electrolyte storage device according to claim 12, wherein the raw material of the surface layer is a resin comprising any one of polypropylene, polyethylene, polystyrene, polyamide, and polyethylene terephthalate. Claim 15 A method for manufacturing an electrolyte storage device according to claim 12, characterized in that the structure is configured in the shape of a circle, triangle, square, pentagon, or hexagon. Claim 16 A method for manufacturing an electrolyte storage device according to claim 15, wherein the structure has a height of 40 to 60 μm and a diameter or side length of 180 to 220 μm, and the pattern has a spacing between the structures of 80 μm to 120 μm. Claim 17 A method for manufacturing an electrolyte storage device configured to store an electrolyte and inject the electrolyte into a secondary battery, comprising the steps of: providing a mold shaft; using a laser to create an intaglio pattern in which a three-dimensional structure is continuously formed on the outer surface of the mold shaft; cutting the mold shaft at equal intervals; inserting the cut mold shaft into the interior of the electrolyte storage device; pressing the cut mold shaft onto the inner surface of the electrolyte storage device; and removing the mold shaft from the electrolyte storage device. Claim 18 A method for manufacturing an electrolyte storage device according to claim 17, wherein the mold shaft is composed of a material including any one of stainless steel, stainless steel alloy, titanium alloy, nickel alloy, and carbon fiber. Claim 19 A method for manufacturing an electrolyte storage device according to claim 17, wherein the surface layer raw material is a resin comprising any one of polypropylene, polyethylene, polystyrene, polyamide, and polyethylene terephthalate. Claim 20 A method for manufacturing an electrolyte storage device according to claim 17, wherein the structure is configured in the shape of a circle, triangle, square, pentagon, or hexagon.

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