Secondary battery and method for manufacturing a secondary battery

Abstract

The present invention provides a secondary battery and a method for manufacturing a secondary battery. [Solution] This disclosure relates to a secondary battery and a method for manufacturing a secondary battery, and the technical problem to be solved is to provide a secondary battery and a method for manufacturing a secondary battery in which the mixture applied to the electrode plate is uniformly applied. To this end, this disclosure provides a secondary battery comprising an electrode plate substrate, a mixture portion coated with a mixture containing an active material on the outside of the electrode plate substrate, and a hydrophobic coating portion that forms a coating layer containing a hydrophobic substance on the electrode plate substrate located outside the boundary of the mixture portion, wherein the mixture portion is coated after the hydrophobic coating portion is coated.

Description

Technical Field

[0001] The present disclosure relates to a secondary battery and a method for manufacturing the secondary battery.

Background Art

[0002] Unlike a primary battery that cannot be charged, a secondary battery is a battery that can be charged and discharged. A low-capacity secondary battery is used in portable small electronic devices such as smartphones, feature phones, notebook computers, digital cameras, and video cameras, and a high-capacity secondary battery is widely used as a power source for motor drive such as hybrid vehicles and electric vehicles and a battery for power storage. Such a secondary battery includes an electrode assembly composed of a positive electrode and a negative electrode, a case that houses the electrode assembly, electrode terminals connected to the electrode assembly, and the like.

[0003] The above information disclosed in the technology that is the background of such an invention is for improving the understanding of the background of the present invention, and thus may include information that does not constitute the prior art.

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present invention provides a secondary battery and a method for manufacturing the secondary battery in which an agent coated on a plate can be uniformly applied.

[0005] However, the technical problems to be solved by the present invention are not limited to the above problems, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

Means for Solving the Problems

[0006] An exemplary secondary battery according to an embodiment of the present invention for solving the above technical problems may include a plate base material, an agent portion coated with an agent containing an active material on the outside of the plate base material, and a hydrophobic coating portion forming a coating layer containing a hydrophobic substance on the plate base material located outside the boundary of the agent portion.

[0007] For example, the compound portion may be hydrophilic, and the hydrophobic coating portion may include a first material comprising at least one of nanosilica, fluorinated nanosilica, polyurethane, non-acetic acid silicon, and a fluorocarbon compound.

[0008] For example, the hydrophobic coating portion is used as a solvent to be mixed with the first material, and further contains a second material containing ethanol. After the hydrophobic coating portion is coated, the mixture portion is coated, and the hydrophobic coating portion does not need to be fluid when the mixture portion is coated.

[0009] As an example, the hydrophobic coating portion may have a strip-shaped coating layer formed on both sides in the width direction of the mixture portion.

[0010] For example, the electrode plate substrate is the negative electrode, and the mixture portion may contain at least one of a conductive agent, a binder, an additive, and an active material.

[0011] For example, the thickness of the hydrophobic coating portion may be the same as or less than the thickness of the combined compound portion.

[0012] For example, the electrode plate substrate may contain copper (Cu).

[0013] An exemplary method for manufacturing a secondary battery according to one embodiment of the present invention may include a supply step of supplying an electrode plate substrate, a first coating step of coating the electrode plate substrate with a hydrophobic coating portion containing a hydrophobic substance, and a second coating step of coating the outside of the electrode plate substrate with a mixture portion containing an active material after the first coating step.

[0014] As an example, the mixture portion is hydrophilic, the first coating step uses a first material comprising at least one of nanosilica, fluorinated nanosilica, polyurethane, non-acetic acid silicon, and a fluorocarbon compound, the first coating step uses a second material comprising ethanol as a solvent to be mixed with the first material, and the second coating step may be carried out in a state in which the hydrophobic coating portion does not have fluidity.

[0015] As an example, the process may further include a drying step after the first coating step, in which a drying unit is activated to dry the hydrophobic coating.

[0016] For example, the drying step may include at least one drying method, such as heat drying and ultraviolet drying.

[0017] As an example, a correction step may be further included between the first coating step and the drying step to correct the coating shape of the hydrophobic coated portion.

[0018] For example, the first coating step may involve powdering the first material, mixing it with the second material to form a slurry, and then coating the electrode plate substrate with the slurry.

[0019] For example, the first coating step may involve applying an adhesive component to the electrode substrate, followed by coating the electrode substrate with a slurry.

[0020] For example, the first coating step may involve mixing an adhesive component into the slurry, and then coating the electrode plate substrate with the slurry.

[0021] As an example, the first coating step may involve coating the electrode plate substrate with slurry using a slot die method. [Effects of the Invention]

[0022] According to the present invention, by providing a hydrophobic coating portion, the spread of the active material portion can be prevented, the installation of the active material portion can be made uniform, and the energy density can be improved.

[0023] In addition, it is possible to solve the problem that the amount of the active material portion is insufficient at the boundary of the active material portion, improve the charge / discharge performance of the secondary battery, and improve productivity.

[0024] However, the effects obtained through the present invention are not limited to the above-described effects, and other technical effects not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0025] The following drawings attached to this specification illustrate preferred embodiments of the present invention and play a role in better understanding the technical idea of the present invention together with the detailed description of the invention to be described later. Therefore, the present invention should not be construed as being limited to the matters described in such drawings.

Brief Description of the Drawings

[0026] [Figure 1] It is a cross-sectional view showing a positive electrode, a negative electrode, and a separator of a secondary battery according to an embodiment of the present invention. [Figure 2] It is a front view showing an installation state of a coating module and a drying unit according to an embodiment of the present invention. [Figure 3] It is a perspective view showing an installation state of a coating module and a drying unit according to an embodiment of the present invention. [Figure 4] It is a plan view showing a state in which a hydrophobic coating portion and an active material portion are formed on a current collector substrate according to an embodiment of the present invention. [Figure 5] It is a cross-sectional view showing a state in which a hydrophobic coating portion and an active material portion are formed on a current collector substrate according to an embodiment of the present invention. [Figure 6] It is a cross-sectional view showing a state in which a hydrophobic coating portion and an active material portion are formed on a current collector substrate according to an embodiment of the present invention. [Figure 7]This is a cross-sectional view showing a state in which a hydrophobic coating portion and a composite material portion are formed on an electrode plate substrate according to one embodiment of the present invention. [Figure 8] This is a plan view showing a coating module and drying section provided according to one embodiment of the present invention. [Figure 9] This is a plan view showing a state in which a guide portion is provided between the coating module and the drying portion according to one embodiment of the present invention. [Figure 10] This is a plan view showing how the hydrophobic coating portion is aligned by a guide portion according to one embodiment of the present invention. [Figure 11] This is a perspective view showing a coated module according to another embodiment of the present invention. [Figure 12] A perspective view showing a coating module according to another embodiment of the present invention. [Figure 13] This flowchart shows a method for manufacturing a secondary battery according to one embodiment of the present invention. [Modes for carrying out the invention]

[0027] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. First, terms and words used herein and in the claims should not be interpreted to be limited to their ordinary or dictionary meanings, but rather should be interpreted as meanings and concepts consistent with the technical idea of ​​the present invention, based on the principle that inventors can appropriately define the concepts of terms in order to best describe their invention. Accordingly, it should be understood that the embodiments described herein and the configurations shown in the drawings represent only some of the most preferred embodiments of the present invention and do not represent the entire technical idea of ​​the present invention, and that there may be various equivalents and modifications that can replace them at the time of filing. Also, where used herein, “comprise, include” and / or “comprising, including” specify the presence of the shapes, figures, stages, actions, members, elements, and / or groups thereof mentioned, and do not exclude the presence or addition of one or more other shapes, figures, actions, members, elements, and / or groups thereof. Also, when describing embodiments of the present invention, “may” and “may include” may include one or more embodiments of the present invention.

[0028] Furthermore, to aid in understanding the present invention, the accompanying drawings may be shown with exaggerated dimensions of some components rather than at actual scale. Also, the same reference numeral may be assigned to the same component in different embodiments.

[0029] The statement that two comparison subjects are "identical" means that they are "substantially identical." Therefore, "substantially identical" may include deviations that are considered low in this industry, for example, deviations of 5% or less. Furthermore, the uniformity of any parameter within a given domain means that it is uniform from an average perspective.

[0030] While 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 simply used to distinguish one component from another, and it goes without saying that, unless otherwise stated, the first component may also be the second component.

[0031] Throughout the specification, unless otherwise stated, each component may be singular or plural.

[0032] The fact that any configuration is positioned above (or below) a component or on top of (or below) a component means that not only is the configuration positioned in contact with the top (or bottom) surface of the component, but other configurations may be interposed between the component and any configuration positioned on (or below) it.

[0033] Furthermore, when it is stated that one component is “connected,” “joined,” or “connected” to another component, it should be understood that the components may be directly connected to or able to be connected to one another, but may also be “interposed” between each component, or each component may be “connected,” “joined,” or “connected” through other components. Also, when it is stated that one part is electrically coupled to another part, this includes not only direct connection but also connection via other elements in between.

[0034] Throughout the specification, "A" and / or "B" means A, B, or A and B unless otherwise specified. That is, "and / or" includes all or any combination of the enumerated items. "C through D" means C to D unless otherwise specified.

[0035] Hereinafter, a secondary battery 1 according to one embodiment of the present invention will be described with reference to the drawings. Figure 1 is a cross-sectional view showing a positive electrode 50, a negative electrode 60, and a separator 40 of a secondary battery 1 according to one embodiment of the present invention. Referring to Figure 1, the secondary battery according to this embodiment may include at least one electrode assembly wound between a positive electrode 50 and a negative electrode 60 with an insulator separator 40 in between. The secondary battery 1 may also include a case in which the electrode assemblies are housed and a cap assembly coupled to the opening of the case.

[0036] In this embodiment, the secondary battery described is a prismatic lithium-ion secondary battery. However, the present invention is not limited thereto, and may be applied to various types of batteries, such as lithium polymer batteries and cylindrical batteries.

[0037] The positive electrode 50 and the negative electrode 60 may include a coated portion, which is a region on which an active material is applied to a current collector made of a thin metal foil, and a plain portion, which is a region on which the active material is not coated. In the present invention, the current collector of the negative electrode 60 can be called the electrode plate base material 10, and the coated portion of the negative electrode 60 can be called the mixture portion 20.

[0038] The positive electrode 50 and the negative electrode 60 are wound together via a separator 40, which is an insulator. However, the present invention is not limited thereto, and the electrode assembly may have a structure in which the positive electrode 50 and the negative electrode 60, each made of multiple sheets, are alternately stacked via a separator 40.

[0039] The case forms the overall appearance of the secondary battery and may be made of a conductive metal such as aluminum, aluminum alloy, or nickel-plated steel. The case may also provide space for housing the electrode assembly.

[0040] The cap assembly may include a cap plate that covers the opening of the case, and the case and cap plate may be made of a conductive material. Here, the positive electrode 50 and negative electrode 60 terminals, which are electrically connected to the positive electrode 50 or negative electrode 60, may be provided so as to protrude outward through the cap plate.

[0041] Furthermore, the outer surfaces of the upper columns of the positive electrode 50 and negative electrode 60 terminals that protrude from the outside of the cap plate may be threaded and fixed to the cap plate with nuts.

[0042] However, the present invention is not limited thereto, and the positive electrode 50 and negative electrode 60 terminals may have a rivet structure and be riveted together, or they may be welded to the cap plate.

[0043] Furthermore, the cap plate may be made of a thin sheet and be bonded to the opening of the case, and the cap plate may have an electrolyte inlet formed therein with a sealing plug, and may also have a vent portion with a notch. In one example, the vent portion can close the vent hole provided in the cap plate. In one example, the vent portion may be bonded or welded to the area surrounding the vent hole (area of ​​the cap plate).

[0044] Although the explanation uses the example of forming the hydrophobic coating portion 30 so that the installation area of ​​the compound portion 20 of the negative electrode 60 is located within a set area, it goes without saying that the present invention is not limited to the negative electrode 60, but can also be applied to the coating portion of the positive electrode 50.

[0045] The compound portion 20, which is the coating portion of the negative electrode 60, may be a fluid slurry. If the compound portion 20 decreases due to abnormal process conditions and environment, the compound portion 20 of the negative electrode 60 facing the end of the coating portion of the positive electrode 50 may be small. As a result, excess lithium ions (Li-ions) that were not accepted by the negative electrode 60 during charging form irreversible products and form an internal short circuit with the positive electrode 50, which can create a fire risk. To reduce the fire risk, a hydrophobic coating portion 30 can be provided at the boundary of the compound portion 20 to prevent a decrease in the amount of compound in the compound portion 20.

[0046] At least one of the electrode plate substrate 10 of the negative electrode 60 and the positive electrode substrate 52 may be coated with a mixture consisting of an active material, a conductor, a binder, and an additive. The negative electrode mixture forms a mixture portion 20, and a positive electrode mixture 54 is formed on the positive electrode substrate 52. The mixture may be coated using various methods, including a slot die coating method.

[0047] In one embodiment of the present invention, the electrode plate substrate 10 is a current collector for the negative electrode 60, and the mixture portion 20 may contain at least one of a conductive agent, a binder, an additive, and an active material.

[0048] The compounding portion 20 can be modified in various ways within the technical concept of coating the outside of the electrode plate substrate 10 with a compounding agent containing an active material. The compounding portion 20 may also be a compounding agent slurry consisting of a solvent and powder. If a hydrophobic coating portion 30 is not provided at the boundary of the slurry-like compounding portion 20, the edges of the compounding portion 20 may flow and spread, reducing the thickness of the edges of the compounding portion 20 as intended in the design. To prevent the phenomenon of insufficient compounding agent coating at the ends of the compounding portion 20, a hydrophobic coating portion 30 is coated at the boundary of the compounding portion 20.

[0049] The slurry of the negative electrode 60 contains distilled water or water and has hydrophilic properties. Therefore, a hydrophobic coating portion 30, which is a hydrophobic substance, may be applied to a position where the mixture portion 20, which is the negative electrode 60 slurry, is not coated or applied. When the hydrophobic coating portion 30 is applied to the electrode plate substrate 10 outside the boundary of the mixture portion 20, the negative electrode 60 mixture slurry, which has fluidity immediately after coating the mixture portion 20, forms a high contact angle at the coating edge. Since the hydrophilic mixture portion 20 is constrained from moving beyond the hydrophobic coating portion 30 by the hydrophobic coating portion 30, the phenomenon of the thickness of the mixture portion 20 decreasing even at the edges of the mixture portion 20 can be minimized.

[0050] Figure 2 is a front view showing the installed state of the coating module 160 and drying section 170 according to one embodiment of the present invention, and Figure 3 is a perspective view showing the installed state of the coating module 160 and drying section 170 according to one embodiment of the present invention. As shown in Figures 2 and 3, the hydrophobic coating section 30 can be modified in various ways within the technical concept of forming a coating layer containing a hydrophobic substance on the electrode plate substrate 10 located outside the boundary of the compound section 20. By providing the hydrophobic coating section 30, the deviation in the width of the compound section 20 can be reduced. The spreading phenomenon of the compound section 20 affects the increase in the width of the compound section 20 and its dispersion. The application of the hydrophobic coating section 30 containing a hydrophobic substance suppresses the spreading of the compound section 20, which is the negative electrode 60 slurry that has been controlled only by the solid content and viscosity of the negative electrode 60 compound slurry, and can make the width of the compound section 20 uniform, which affects the improvement of dispersion.

[0051] On the electrode plate substrate 10 of the negative electrode 60, a hydrophobic coating portion 30 is coated or applied to the boundary of the compound portion 20. The hydrophobic coating portion 30 may be linearly applied in the direction of travel or longitudinal direction D of the electrode plate substrate 10. By installing the hydrophobic coating portion 30, it is possible to prevent the water-based (hydrophilic) negative electrode 60 compound slurry from spreading outside the designed coating area and reducing the amount of compound portion 20.

[0052] The hydrophobic coating portion 30 may be coated before the mixture portion 20 is coated. The hydrophobic coating portion 30 can form a strip-shaped coating layer on both sides of the mixture portion 20 in the width direction W. The hydrophobic coating portion 30 may be coated or applied in a strip shape extending in the longitudinal direction D of the electrode plate substrate 10. The longitudinal direction D of the electrode plate substrate 10 may be the same as the direction of movement of the electrode plate substrate 10. The width direction W and the longitudinal direction D can be perpendicular.

[0053] The hydrophobic substance contained in the hydrophobic coating portion 30 must have stable properties that do not participate in the electrochemical reactions within the secondary battery 1. The hydrophobic coating portion 30 according to one embodiment of the present invention may include a first material comprising at least one of nanosilica, fluorinated nanosilica, polyurethane, non-acetic acid silicon, and a fluorocarbon compound.

[0054] The electrode plate substrate 10 of the negative electrode 60 may contain Cu. In order to apply the hydrophobic coating portion 30 to the electrode plate substrate 10, a powdered hydrophobic substance may be mixed with a solvent such as ethanol as a pretreatment to form a slurry. In this case, since the slurryed hydrophobic substance may adversely affect the coating quality of the slurry which is the mixture portion 20, a separate drying step may be added.

[0055] The application of the slurryed hydrophobic substance may be carried out using a slot die method, similar to the coating of the slurryed mixture portion 20. The coating module 160, which discharges the slurry, may be operated only when there is movement of the electrode substrate 10. Therefore, when the movement of the electrode substrate 10 is stopped, the coating module 160 does not operate, thus preventing the phenomenon of excessive application of the hydrophobic substance to the electrode substrate 10.

[0056] The hydrophobic coating portion 30 according to one embodiment of the present invention may further contain a second material which is used as a solvent to be mixed with the first material and which contains ethanol. The first material contains a hydrophobic substance as described above.

[0057] To form the compound portion 20, the electrode plate substrate 10 must be coated with the negative electrode 60 slurry. The liquid-containing negative electrode 60 slurry can solidify to form the compound portion 20. The electrode plate substrate 10 can pass through multiple rollers to maintain a constant tension.

[0058] The electrode plate substrate 10 can maintain tension by passing through a pair of first rollers 100, and then through a second roller 110 which functions as a backup roll. A coating module 160 and a drying section 170 may be provided between the first rollers 100 and the second rollers 110. The coating module 160 and the drying section 170 may be positioned opposite the movement path of the electrode plate substrate 10.

[0059] The hydrophobic substance discharged from the coating module 160 is applied to and adheres to the electrode base material 10, thereby forming a hydrophobic coating portion 30. The application and adhesion of the hydrophobic substance may be performed when the electrode base material 10 passes over the second roller 110, which functions as a backup roll, or before it passes over the roller. After the upper surface (referenced in Figure 2) of the electrode base material 10 is coated with the hydrophobic substance, the mixture portion 20 may be coated. If both the upper and lower surfaces of the electrode base material 10 are coated with the hydrophobic substance and the mixture slurry simultaneously, the electrode base material 10 may contaminate the rollers as it passes over them, potentially causing problems such as deformation of the hydrophobic coating portion 30. Therefore, the upper surface of the electrode base material 10, which does not come into contact with the rollers, may be coated with the hydrophobic substance and the mixture slurry first, and then the opposite surface of the electrode base material 10 may be coated with the hydrophobic substance and the mixture slurry in a subsequent process.

[0060] A compound supply unit 120 for discharging compound slurry may be provided on the side of the second roller 110, which functions as a backup roll. The compound supply unit 120 can be modified in various ways within the technical concept of supplying compound slurry to the electrode plate substrate 10 to form the compound unit 20. The compound supply unit 120 according to one embodiment of the present invention may include a supply head 130, a connecting pipeline 140, and a control valve 150.

[0061] The supply head 130 is positioned opposite the second roller 110. The supply head 130 supplies the mixture slurry to the outer surface of the electrode plate substrate 10 as it moves along the outer surface of the second roller 110. The supply head 130 according to one embodiment of the present invention may include a head body 132 positioned opposite the second roller 110 and an inner tank 134 located inside the head body 132 for storing the mixture slurry supplied through the connecting conduit 140. The supply head 130 includes an inner conduit 136 extending from the inner tank 134 toward the second roller 110.

[0062] The connecting conduit 140 extends inside the head body 132 and is connected to the inner tank 134. The amount of mixture slurry passing through the connecting conduit 140 may be adjusted by the operation of a control valve 150 connected to the connecting conduit 140. The inner tank 134 forms a space for storing the mixture slurry inside the head body 132. After the mixture slurry stored in the inner tank 134 is moved through the inner conduit 136 which communicates with the inner tank 134, it may be applied to the outside of the electrode plate substrate 10.

[0063] The coating module 160 is provided between the first roller 100 and the second roller 110, and may be provided above the electrode plate substrate 10 as it moves from the first roller 100 to the second roller 110. The coating module 160 may be supplied with a hydrophobic slurry and applied to the upper side of the electrode plate substrate 10 to form a hydrophobic coating portion 30. The configuration of the coating module 160 may be the same as that of the mixture supply unit 120, and thus the detailed configuration of the coating module 160 is omitted.

[0064] A drying section 170 may be provided at a position opposite the electrode substrate 10 that has passed through the coating module 160 in order to dry the hydrophobic slurry discharged from the coating module 160. The drying section 170 may dry the hydrophobic slurry using at least one of heat drying and ultraviolet drying to form the hydrophobic coating section 30.

[0065] The coating module 160 may be provided on both sides of the electrode plate substrate 10 in the width direction W. The drying section 170 may also be provided on both sides of the electrode plate substrate 10 in the width direction W. The drying section 170 may be provided on the rear side of the electrode plate substrate 10 in the longitudinal direction (direction of travel) D, relative to the coating module 160. Therefore, the slurry containing hydrophobic substances discharged from the coating module 160 onto the electrode plate substrate 10 is dried by the drying section 170, preventing contamination of rollers and other components in subsequent processes.

[0066] Figure 4 is a plan view showing a state in which a hydrophobic coating portion 30 and a composite portion 20 are formed on an electrode plate substrate 10 according to one embodiment of the present invention. As shown in Figure 4, strip-shaped hydrophobic coating portions 30 extending in the longitudinal direction D are located on both sides of the electrode plate substrate 10 in the width direction W. The ends of the hydrophobic coating portion 30 and the electrode plate substrate 10 are separated by a set interval to form plain portions.

[0067] Hydrophobic coating portions 30 are provided on both sides of the compound portion 20 in the width direction W. First, after coating the hydrophobic coating portions 30, a compound slurry for making the compound portion 20 is applied to the electrode plate substrate 10. The fluid compound slurry is provided only in the area defined by the hydrophobic coating portions 30.

[0068] Figures 5 to 7 are cross-sectional views showing a state in which a hydrophobic coating portion 30 and a compound portion 20 are formed on an electrode plate substrate 10 according to one embodiment of the present invention. As shown in Figure 5, the shape and end contact angle of the negative electrode 60 compound slurry can be adjusted by the coating thickness of the hydrophobic coating portion 30, and thus the end contact angle and shape of the compound portion 20 can be adjusted. Since the shape of the compound portion 20 can be controlled, the charge and discharge performance of the secondary battery 1 can be optimized.

[0069] The hydrophobic substance used in the hydrophobic coating portion 30 has stability that does not participate in the electrochemical reactions within the secondary battery 1, thus maintaining the stability of the secondary battery 1.

[0070] The coating thickness of the hydrophobic coating portion 30 must be lower than the coating height of the mixture slurry, which has flowing properties, and preferably at a level similar to the target height of the mixture portion 20 in the rolling process. If the hydrophobic coating portion 30 is coated thicker than the mixture slurry of the negative electrode 60, the hydrophobic coating portion 30 will be pressed down by the rolling rollers and cover the upper side of the mixture portion 20, which may hinder the movement of lithium ions (Li-ions) during charge and discharge operations and reduce charge and discharge performance. In one embodiment of the present invention, the thickness of the hydrophobic coating portion 30 may be the same as or less than the thickness of the mixture portion 20.

[0071] The shape of both ends of the compounding portion 20 in the width direction W may be changed according to the height of the hydrophobic coating portion 30. When the height of the hydrophobic coating portion 30 is 20% or less of the height of the compounding portion 20, the contact angle of the compounding portion 20 becomes higher. The contact angle is the angle between the inclined surface of the width direction (W) end of the compounding portion 20 and the electrode plate base material 10.

[0072] As shown in Figure 6, increasing the height of the hydrophobic coating portion 31 lowers the contact angle of the mixture portion 20. As shown in Figure 7, if the height of the hydrophobic coating portion 32 increases to a height slightly lower than that of the mixture portion 20, the contact angle of the mixture portion 20 may become lower than the previous contact angle. The shape of the mixture slurry at the coating edge of the electrode plate substrate 10 is determined by the contact angle formed between the slurry and the electrode plate substrate 10.

[0073] Figure 8 is a plan view showing a coating module 160 and a drying section 170 provided according to one embodiment of the present invention. As shown in Figure 8, the hydrophobic coating section 30 may be dried by the drying section 170 using at least one of heat drying and ultraviolet drying. Assuming that the electrode plate substrate 10 moves toward the upper side in the longitudinal direction D (reference to Figure 8), the drying section 170 may be provided on the upper side in the longitudinal direction D of the coating module 160.

[0074] Figure 9 is a plan view showing a state in which a guide portion 180 is provided between a coating module 160 and a drying portion 170 according to one embodiment of the present invention, and Figure 10 is a plan view showing a state in which the hydrophobic coating portion 30 is aligned by the guide portion 180 according to one embodiment of the present invention. As shown in Figures 9 and 10, the hydrophobic slurry sprayed from the coating module 160 does not have to be straight in shape. Therefore, the guide portion 180 may be provided between the coating module 160 and the drying portion 170 to correct the shape of the hydrophobic coating portion 30. The guide portion 180 may also be installed to improve the phenomenon in which the hydrophobic slurry-like hydrophobic coating portion 30 applied to the upper side of the electrode plate substrate of the negative electrode 60, or the hydrophobic substance applied on the components of adhesives or glues, is applied unevenly and the boundary becomes unclear.

[0075] A guide section 180 according to one embodiment of the present invention includes a first guide 182 provided on one side in the width direction W facing the movement path of the hydrophobic coating section 30, and a second guide 184 provided at a position facing the first guide 182 via the hydrophobic coating section 30. The hydrophobic coating section 30 is located between the first guide 182 and the second guide 184, and the inlets and outlets of the first guide 182 and the second guide 184 are provided spaced apart from each other. The guide section 180 is provided in a fixed state together with the coating module 160. The length L1 of the inlet width of the first guide 182 and the second guide 184 is greater than the length L2 of the outlet width. Since the inlet of the guide section 180 is larger than the outlet, the hydrophobic coating section 30 that moves from the inlet of the guide section 180 to the outlet of the guide section 180 has the same width as the outlet width of the guide section 180, and the shape of the hydrophobic coating section 30 is corrected to a straight line extending in the longitudinal direction D.

[0076] According to the present invention as described above, the installation of the hydrophobic coating portion 30 prevents the spreading of the compound portion 20, ensuring uniform installation of the compound portion 20 and improving energy density. Furthermore, it solves the problem of insufficient amount of compound portion 20 at the boundaries of the compound portion 20, improving the charge and discharge performance of the secondary battery 1 and increasing productivity.

[0077] Figure 13 is a flowchart illustrating a method for manufacturing a secondary battery 1 according to one embodiment of the present invention. As shown in Figure 13, the exemplary method for manufacturing a secondary battery 1 according to one embodiment of the present invention includes a supply step S10 for supplying an electrode plate substrate 10. The electrode plate substrate 10 may be moved through a first roller 100 and a second roller 110.

[0078] The process includes a first coating step S20 in which a hydrophobic coating portion 30 containing a hydrophobic substance is coated onto the electrode plate substrate 10 after the supply step. The first coating step S20 may use a first material containing at least one of nanosilica, fluorinated nanosilica, polyurethane, non-acetic acid silicon, and a fluorocarbon compound. The first coating step S20 may involve powdering the first material, mixing the first material with a second material used as a solvent to form a slurry, and then coating the electrode plate substrate 10 with the slurry.

[0079] In the first coating step S20, an adhesive component may be applied to the electrode plate substrate 10, and then a slurry may be coated onto the electrode plate substrate 10. As the adhesive, a polymer adhesive such as polyurethane, polyacrylate, or epoxy resin may be used.

[0080] In the first coating step S20, an adhesive component may be mixed into the slurry, and then the slurry may be coated onto the electrode plate substrate 10. A polymer adhesive may be used as the adhesive. For the application of the hydrophobic substance, after applying the adhesive component onto the electrode plate substrate 10, a powdered hydrophobic substance may be attached to the adhesive component to form a hydrophobic coating portion 30.

[0081] Alternatively, a hydrophobic substance, which is a mixture of an adhesive component and a powdered hydrophobic substance, may be applied to the electrode plate substrate 10 using a slot die method.

[0082] Between the first coating step S20 and the drying step, a correction step may be further included to correct the coating shape of the hydrophobic coating portion 30. The hydrophobic coating portion 30 discharged from the coating module 160 and applied to the electrode plate substrate 10 may pass through a guide portion 180, which includes a first guide 182 and a second guide 184, to correct its shape.

[0083] After the first coating step S20, a drying step S40 may be further included in which the drying unit 170 operates to dry the hydrophobic coating unit 30. The drying step S40 may include at least one drying method, such as heat drying and ultraviolet drying. The hydrophobic coating unit 30 that has passed through the guide unit 180 or applied by the coating module 160 passes through the drying unit 170 to be dried.

[0084] The process includes a second coating step S50 in which a mixture portion 20 containing an active material is coated onto the outside of the electrode plate substrate 10 after the first coating step S20. After the hydrophobic coating portion 30 has finished drying, a mixture slurry is applied to the electrode plate substrate 10 via the mixture supply unit 120 to form the mixture portion 20. The mixture portion 20 does not encroach on the area of ​​the hydrophobic coating portion 30, and the shape of the edges of the mixture portion 20 may be controlled according to the height of the hydrophobic coating portion 30.

[0085] Figure 11 is a perspective view showing a coating module 260 according to another embodiment of the present invention, and Figure 12 is a perspective view showing a coating module 260 according to another embodiment of the present invention. As shown in Figures 11 and 12, the coating module 260 according to another embodiment of the present invention can be modified in various ways within the technical concept of applying a hydrophobic slurry and a substance of adhesive or bonding component to an electrode plate substrate 10. The coating module 260 according to another embodiment of the present invention may include a first coating head 262, a first conduit 264, a first tank 266, a first spray nozzle 268, a second coating head 272, a second conduit 274, a second tank 276, and a second spray nozzle 278. The body of the coating module 260 includes the first coating head 262 and the second coating head 272.

[0086] Inside the first coating head 262 is a first tank 266 in which hydrophobic slurry is stored. The hydrophobic slurry is transferred to the first tank 266 via a first conduit 264 connected to the first tank 266. A first injection nozzle 268 extending from the first tank 266 extends from the first tank 266 to the outlet of the first coating head 262. Thus, the hydrophobic slurry that has moved from the first tank 266 to the first injection nozzle 268 is discharged toward the electrode plate substrate 10.

[0087] Inside the second coating head 272, which is opposite the first coating head 262, is a second tank 276 in which a substance containing adhesive or bonding agents is stored. The substance containing adhesive or bonding agents is transmitted to the second tank 276 via a second conduit 274 connected to the second tank 276. A second spray nozzle 278 extends from the second tank 276 to the outlet of the second coating head 272. Thus, the substance containing adhesive or bonding agents that has moved from the second tank 276 to the second spray nozzle 278 is discharged toward the electrode plate substrate 10.

[0088] After applying an adhesive or tack component to the electrode plate substrate 10 through a second spray nozzle 278 to form an adhesive layer 300, a hydrophobic slurry may be coated onto the electrode plate substrate 10 through a first spray nozzle 268 to form a hydrophobic coating portion 30. The adhesive or tack component may be a polymer adhesive such as polyurethane, polyacrylate, or epoxy resin.

[0089] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and various modifications and variations are possible within the equivalent scope of the technical concept of the present invention and the claims described below by persons with ordinary skill in the art to which the present invention pertains. [Explanation of Symbols]

[0090] 1: Secondary battery 10: Plate base material 20: Combination Pharmacy Department 30, 31, 32: Hydrophobic coating section 40: Separator 50: Positive electrode 52: Positive electrode substrate 54: Cathode mixture 60: Negative electrode 100: Laura No. 1 110: The Second Laura 120: Combination drug supply unit 130: Supply head 132: Head body 134: Inner tank 136:Inner duct 140: Connecting pipe 150: Control valve 160: Coating Module 170:Drying section 180: Guide Section 182: The First Guide 184: The Second Guide 260: Coating Module 262: First coating head 264: First pipeline 266: The first tank 268: First injection nozzle 272: Second coating head 274: Second pipeline 276: Second Tank 278: Second injection nozzle 300: Adhesive layer L1: Entrance width length L2: Length of outlet width W: width direction D: Length direction S10: Supply Stage S20: First coating stage S30: Orthodontic treatment stage S40: Drying stage S50: Second coating stage

Claims

1. electrode plate base material, The electrode plate substrate is coated with a mixture containing an active material on its outer surface, and The electrode plate substrate located outside the boundary of the mixture portion includes a hydrophobic coating portion that forms a coating layer containing a hydrophobic substance, A secondary battery characterized in that the compound portion is hydrophilic, the hydrophobic coating portion comprises a first material comprising at least one of nanosilica, fluorinated nanosilica, polyurethane, non-acetic acid silicon, and a fluorocarbon compound, the hydrophobic coating portion further comprises a second material comprising ethanol, which is used as a solvent to be mixed with the first material, the compound portion is coated after the hydrophobic coating portion is coated, and the hydrophobic coating portion does not have fluidity when the compound portion is coated.

2. In the secondary battery according to claim 1, The hydrophobic coating portion is characterized by forming a strip-shaped coating layer on both sides in the width direction of the mixture portion, thereby providing a secondary battery.

3. In the secondary battery according to claim 1, A secondary battery characterized in that the electrode plate substrate is a negative electrode, and the mixture portion comprises at least one of a conductive agent, a binder, an additive, and the active material.

4. In the secondary battery according to claim 1, A secondary battery characterized in that the thickness of the hydrophobic coating portion is the same as or less than the thickness of the composite portion.

5. In the secondary battery according to claim 1, A secondary battery characterized in that the electrode plate substrate contains Cu.

6. In the supply stage, the electrode plate substrate is supplied. A first coating step involves coating the electrode plate substrate with a hydrophobic coating portion containing a hydrophobic substance, and The process includes a second coating step in which, after the first coating step, a mixture containing an active material is coated onto the outside of the electrode plate substrate. A method for manufacturing a secondary battery, characterized in that the mixture portion is hydrophilic, the first coating step uses a first material comprising at least one of nanosilica, fluorinated nanosilica, polyurethane, non-acetic acid silicon, and a fluorocarbon compound, the first coating step uses a second material comprising ethanol as a solvent to be mixed with the first material, and the second coating step is performed in a state in which the hydrophobic coating portion does not have fluidity.

7. In the method for manufacturing a secondary battery according to claim 6, A method for manufacturing a secondary battery, characterized in that, after the first coating step, a drying step is further included in which a drying unit is activated to dry the hydrophobic coating.

8. In the method for manufacturing a secondary battery according to claim 7, A method for manufacturing a secondary battery, characterized in that the drying step includes at least one drying method, which is thermal drying and ultraviolet drying.

9. In the method for manufacturing a secondary battery according to claim 7, A method for manufacturing a secondary battery, characterized in that a correction step for correcting the coating shape of the hydrophobic coating portion is further included between the first coating step and the drying step.

10. In the method for manufacturing a secondary battery according to claim 6, A method for manufacturing a secondary battery, characterized in that the first coating step involves turning the first material into a powder, mixing it with the second material to form a slurry, and then coating the electrode plate substrate with the slurry.

11. In the method for manufacturing a secondary battery according to claim 10, A method for manufacturing a secondary battery, characterized in that the first coating step involves applying an adhesive component to the electrode plate substrate, and then coating the electrode plate substrate with the slurry.

12. In the method for manufacturing a secondary battery according to claim 10, A method for manufacturing a secondary battery, characterized in that the first coating step involves mixing an adhesive component into the slurry and then coating the electrode plate substrate with the slurry.

13. In the method for manufacturing a secondary battery according to claim 10, A method for manufacturing a secondary battery, characterized in that the first coating step involves coating the electrode plate substrate with the slurry using a slot die method.

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