Coating apparatus

Abstract

The technical idea of the present invention provides a coating apparatus comprising: a coating die which discharges electrode slurry toward a substrate, and which includes an electrode slurry outlet through which the electrode slurry is discharged; and a flow rate control block which is connected to the outer surface of the coating die facing the substrate and which extends toward the substrate from the outer surface of the coating die, wherein the flow rate control block is spaced apart from the electrode slurry outlet in the direction perpendicular to the width direction of the electrode slurry outlet, and the width of the flow rate control block is less than the width of the electrode slurry outlet.

Description

coating device

[0001] The present invention relates to a coating device.

[0002] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2024-0094323, filed July 17, 2024, and all contents of the document in that Republic of Korea patent application are incorporated herein by reference.

[0003] With the technological development and increasing demand for mobile devices, the demand for secondary batteries as an energy source is rapidly increasing. These secondary batteries essentially include an electrode assembly, which is a power generation element. The electrode assembly has a structure in which a positive electrode, a separator, and an anode are laminated at least once. The positive and negative electrodes are manufactured by coating and drying a positive active material slurry and a negative active material slurry onto a current collector made of aluminum foil and copper foil, respectively. A slot die coater is typically used to coat the positive and negative active material slurries onto the current collector.

[0004] The technical problem to be solved by the present invention is to provide a coating device.

[0005] In order to solve the above-described problem, the technical idea of ​​the present invention provides a coating device including a coating die configured to discharge electrode slurry toward a substrate and including an electrode slurry discharge port for discharging the electrode slurry; and a flow rate control block connected to an outer surface of the coating die facing the substrate and extending from the outer surface of the coating die toward the substrate; wherein the flow rate control block is spaced apart from the electrode slurry discharge port, and a width of the flow rate control block is smaller than a width of the electrode slurry discharge port.

[0006] In exemplary embodiments, the distance between the flow control block and the substrate is characterized by being smaller than the distance between the electrode slurry discharge port of the coating die and the substrate.

[0007] In exemplary embodiments, the electrode slurry discharged from the coating die forms an electrode slurry layer applied on the substrate, and the flow control block is characterized in that it is positioned on the flow path of the electrode slurry layer so as to interfere with the center of the electrode slurry layer.

[0008] In exemplary embodiments, the flow control block is characterized by including a connecting portion inserted into a groove of the coating die and a protrusion protruding from the coating die.

[0009] In exemplary embodiments, the invention further comprises an actuator configured to move the flow control block.

[0010] In exemplary embodiments, the actuator is characterized in that it is configured to move the flow control block to adjust the distance the flow control block protrudes from the coating die.

[0011] In exemplary embodiments, the actuator is characterized in that it is configured to move the flow control block in a direction parallel to the width direction of the electrode slurry discharge port.

[0012] In exemplary embodiments, the actuator is characterized in that it is configured to move the flow control block in a direction perpendicular to the width direction of the electrode slurry discharge port.

[0013] In exemplary embodiments, the coating die includes a first die and a second die spaced apart with the electrode slurry discharge port therebetween, the first die including a groove extending in the width direction of the electrode slurry discharge port; and a first portion and a second portion spaced apart with the groove therebetween, wherein the groove of the first die extends from one side of the first die to the other side and penetrates the first die, and the flow rate control block is characterized by including a connecting portion inserted into the groove of the coating die and a protrusion protruding from the coating die.

[0014] In exemplary embodiments, the second portion of the first die is characterized by further including a pressing rod facing the second die, disposed within the first portion of the first die, and configured to press the second portion of the first die.

[0015] In exemplary embodiments, the coating die further comprises a coating core disposed within the coating die, the coating core communicating with the electrode slurry discharge port and including a passage for delivering the electrode slurry.

[0016] In exemplary embodiments, the coating die is further configured to discharge an insulating liquid toward the substrate, and the coating core is characterized in that it further includes a conduit for delivering the insulating liquid.

[0017] In exemplary embodiments, the coating roll is further configured to transport the substrate, and the distance between the flow control block and the coating roll is characterized in that it is smaller than the distance between the electrode slurry discharge port of the coating die and the coating roll.

[0018] According to exemplary embodiments of the present invention, the coating device includes a flow rate control block configured to locally reduce the flow rate of electrode slurry discharged from the coating die, so that the electrode slurry layer formed by applying the electrode slurry on a substrate can be formed to have a semi-coated portion having a relatively small thickness at its center.

[0019] According to exemplary embodiments of the present invention, in an electrode assembly manufactured by stacking a positive electrode and a negative electrode, the end of the positive electrode facing the end of the negative electrode including the electrode tab has a semi-coated portion having a relatively small thickness, thereby preventing the phenomenon of NP ratio reversal in the electrode assembly. Accordingly, lithium ion precipitation can be prevented during charge and discharge, and the safety and reliability of a secondary battery including the electrode assembly can be improved.

[0020] The effects that can be obtained from the exemplary embodiments of the present invention are not limited to the effects mentioned above, and other effects not mentioned can be clearly derived and understood by those skilled in the art to which the exemplary embodiments of the present disclosure pertain from the following description. In other words, unintended effects resulting from practicing the exemplary embodiments of the present disclosure can also be derived by those skilled in the art from the exemplary embodiments of the present disclosure.

[0021] FIG. 1 is a perspective view showing a coating device according to exemplary embodiments.

[0022] Figure 2 is an exploded perspective view showing a coating device according to exemplary embodiments.

[0023] Fig. 3 is a cross-sectional view showing a coating device according to exemplary embodiments.

[0024] Fig. 4 is a cross-sectional view showing a coating device taken along line IV-IV' of Fig. 3.

[0025] Fig. 5 is a cross-sectional view showing a coating device taken along line V-V' of Fig. 3.

[0026] Figure 6 is a cross-sectional view showing a coating device according to exemplary embodiments.

[0027] Fig. 7 is a cross-sectional view showing a coating device according to exemplary embodiments.

[0028] Figure 8 is a perspective view showing a coating device according to exemplary embodiments.

[0029] Fig. 9 is a cross-sectional view showing a coating device according to exemplary embodiments.

[0030] FIGS. 10 and 11 are cross-sectional views showing a method for manufacturing an electrode assembly according to exemplary embodiments.

[0031] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0032] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0033] In addition, when describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description is omitted.

[0034] Since the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art, the shapes and sizes of components in the drawings may be exaggerated, omitted, or schematically illustrated for clearer explanation. Accordingly, the sizes and proportions of each component do not fully reflect the actual sizes or proportions.

[0035]

[0036] (Example 1)

[0037] Fig. 1 is a perspective view showing a coating device (10) according to exemplary embodiments. Fig. 2 is an exploded perspective view showing a coating device (10) according to exemplary embodiments. Fig. 3 is a cross-sectional view showing a coating device (10) according to exemplary embodiments. Fig. 4 is a cross-sectional view showing a coating device (10) taken along line IV-IV' of Fig. 3. Fig. 5 is a cross-sectional view showing a coating device (10) taken along line V-V' of Fig. 3.

[0038] Referring to FIGS. 1 to 5, a coating device (10) can perform a coating process for manufacturing an electrode for a secondary battery by applying a coating solution on a substrate (510). The coating solution can include electrode slurry (520) and an insulating solution (530). The coating device (10) can discharge the electrode slurry (520) and the insulating solution (530) toward the substrate (510) moving by the coating roll (150). The electrode slurry (520) applied on the substrate (510) becomes an electrode slurry layer (521), and the insulating solution (530) applied on the substrate (510) can become an insulating layer covering the side of the electrode slurry layer (521).

[0039] The above-described substrate (510) may be a current collector. The current collector may be a positive current collector. For example, the positive current collector may include stainless steel, aluminum, nickel, titanium, calcined carbon, etc. The current collector may be a negative current collector. For example, the negative current collector may include copper, stainless steel, nickel, titanium, calcined carbon, etc.

[0040] The electrode slurry (520) may include an electrode active material, a conductive material, a binder, and an additive. The electrode active material may include a positive electrode active material or a negative electrode active material. For example, the positive electrode active material may include a lithium metal composite oxide including nickel (Ni), cobalt (Co), and manganese (Mn). For example, the negative electrode active material may include at least one of a carbon material and a silicon material. The carbon material may refer to a carbon material having carbon atoms as a main component. The silicon material is a particle including silicon (Si) as a metal component as a main component, and may include at least one of silicon (Si) particles and silicon oxide particles.

[0041] The insulating solution (530) may include inorganic particles, phenolic compounds, and a binder. For example, the inorganic particles may include one or more aluminum minerals selected from the group consisting of boehmite, gibbsite, diaspore, alunite, and nepheline. For example, the phenolic particles may enhance the dispersibility of the inorganic particles included in the insulating solution (530). These phenolic compounds may include at least one of tannic acid, baicalein, luteolin, taxifolin, myricetin, quercetin, rutin, catechin, epigallocatechin gallate, butein, piceatenol, pyrogallic acid, ellagic acid, amylose, amylopectin, and xanthan gum.

[0042] In exemplary embodiments, the coating device (10) may be configured to simultaneously discharge electrode slurry (520) and insulating liquid (530) toward the substrate (510) and to simultaneously apply the electrode slurry (520) and insulating liquid (530) on one surface of the substrate (510). The insulating liquid (530) may be applied onto the substrate (510) to cover both sides of the electrode slurry layer (521) applied onto the substrate (510). The insulating liquid (530) may be applied onto the substrate (510) to cover both sides of the electrode slurry layer (521), thereby suppressing or preventing a sliding phenomenon in which the thickness of the electrode slurry layer (521) gradually decreases at the outer portion of the electrode slurry layer (521), and reducing a thickness deviation of the electrode slurry layer (521) applied onto the substrate (510).

[0043] The coating device (10) may include a coating die (110), a coating shim (120), a coating roll (150), and a flow control block (160).

[0044] The coating die (110) can receive electrode slurry (520) and insulating liquid (530) from the outside, and can discharge the electrode slurry (520) and insulating liquid (530) toward the substrate (510). The coating die (110) can include an electrode slurry discharge port (114) configured to discharge the electrode slurry (520) and an insulating liquid discharge port (115) configured to discharge the insulating liquid (530). The electrode slurry discharge port (114) and the insulating liquid discharge port (115) can be provided on a die lip of the coating die (110) facing the substrate (510) supported on the coating roll (150). The electrode slurry discharge port (114) and the insulating liquid discharge port (115) can be adjacent to each other in the first direction (D1).

[0045] The electrode slurry discharge port (114) may have a slit shape extending in the first direction (D1) and may be configured to discharge the electrode slurry (520) in a discharge direction (DD) parallel to the second direction (D2). The width direction of the electrode slurry discharge port (114) may be parallel to the first direction (D1). The length of the electrode slurry discharge port (114) along the first direction (D1) may be greater than the length of the electrode slurry discharge port (114) along the third direction (D3).

[0046] The insulating liquid discharge ports (115) may be arranged on both sides of the electrode slurry discharge ports (114). The insulating liquid discharge ports (115) may have a slit shape extending in the first direction (D1) and may be configured to discharge the insulating liquid (530) in a direction parallel to the second direction (D2). In exemplary embodiments, the coating die (110) may include a plurality of electrode slurry discharge ports (114) spaced apart in the first direction (D1), and one insulating liquid discharge port (115) may be provided on each side of each electrode slurry discharge port (114).

[0047] The coating die (110) may include a first die (111) and a second die (112). The first die (111) may include a manifold (113) that receives electrode slurry (520). The manifold (113) may include a space in which electrode slurry (520) provided from the outside is received. The second die (112) may be coupled to the first die (111) so as to cover the manifold (113) of the first die (111). The die lip of the coating die (110) may include the die lip of the first die (111) and the die lip of the second die (112). The first die (111) may have an electrode slurry discharge port (114) and an insulating liquid discharge port (115) provided between the die lip of the first die (111) and the die lip of the second die (112). The first die (111) can be spaced apart from the second die (112) with an electrode slurry discharge port (114) and an insulating liquid discharge port (115) therebetween.

[0048] The first die (111) may include a groove (117) extending inward from an outer surface facing the substrate (510). The groove (117) may extend continuously between one side and the other side of the first die (111) along a first direction (D1) and may penetrate the first die (111) in the first direction (D1). Since the groove (117) penetrates the first die (111) in the first direction (D1), the groove (117) may be exposed on each of the two side surfaces of the first die (111) along the first direction (D1). The first die (111) may include a first portion (1111) and a second portion (1113) spaced apart from each other in a third direction (D3) with the groove (117) therebetween. The second part (1113) of the first die (111) can directly face the second die (112).

[0049] The coating shim (120) can be placed within the coating die (110). The coating shim (120) can be inserted into a space provided between the first die (111) and the second die (112). The coating shim (120) can provide an electrode slurry path (129) extending in a second direction (D2) from the manifold (113) of the coating die (110) to the electrode slurry discharge port (114) of the coating die (110). The electrode slurry path (129) can transfer electrode slurry (520) from the manifold (113) of the coating die (110) to the electrode slurry discharge port (114) of the coating die (110).

[0050] The coating shim (120) may include a body shim (130) and a spacer shim (140).

[0051] The body shim (130) may be fastened to at least one of the first die (111) and the second die (112) by a fastening member such as a bolt. The body shim (130) may include a center body (131) and a pair of side bodies (133). The center body (131) may be disposed on one side of the manifold (113) and may be spaced apart in a first direction (D1) from the discharge port (114) of the coating die (110) with the manifold (113) therebetween. The center body (131) may extend in the width direction of the manifold (113) (for example, in the D1 direction) along one edge of the manifold (113). The pair of side bodies (133) may be spaced apart in the width direction of the manifold (113) with the manifold (113) therebetween. One of the pair of side bodies (133) may be connected to one end of the center body (131) along the first direction (D1) and may extend in a second direction (D2) from the center body (131) toward the die lip of the coating die (110). The other of the pair of side bodies (133) may be connected to the other end of the center body (131) along the first direction (D1) and may extend in a second direction (D2) from the center body (131) toward the die lip of the coating die (110). One of the pair of side bodies (133) may be referred to as a first side body (133), and the other of the pair of side bodies (133) may be referred to as a second side body (133).

[0052] The spacer shim (140) may be fastened to at least one of the first die (111) and the second die (112) by a fastening member such as a bolt. The spacer shim (140) may be disposed between the manifold (113) and the die lip of the coating die (110) in the second direction (D2). The spacer shim (140) may include an insulating liquid path (141) configured to communicate with the insulating liquid discharge port (115) and deliver the insulating liquid (530) toward the insulating liquid discharge port (115). The spacer shim (140) may discharge the insulating liquid (530) in a direction substantially parallel to the discharge direction (DD) of the electrode slurry (520). For example, the insulating liquid (530) discharged from the spacer core (140) can be discharged to the outside of the coating die (110) through the insulating liquid discharge port (115) of the coating die (110). For example, the insulating liquid (530) provided from the outside can be transferred to the insulating liquid path (141) of the spacer core (140) through the internal path of the second die (112), and the insulating liquid (530) discharged to the end of the insulating liquid path (141) can be discharged to the substrate (510) through the insulating liquid discharge port (115) of the coating die (110).

[0053] The coating core (120) may include a plurality of spacer cores (140) mounted on the coating die (110). The plurality of spacer cores (140) may be arranged in a first direction (D1) and may be spaced apart from each other in the first direction (D1). An electrode slurry path (129) of the coating core (120) may be defined by neighboring spacer cores (140), and a width of the electrode slurry path (129) may be a distance along the first direction (D1) between neighboring spacer cores (140). In exemplary embodiments, a spacer core (140) may be arranged on each of both sides of the electrode slurry path (129) of the coating core (120).

[0054] In exemplary embodiments, the plurality of spacer cores (140) may include a first edge spacer core connected to one of the pair of side bodies (133), a second edge spacer core connected to the other of the pair of side bodies (133), and a center spacer core provided between the first edge spacer core and the second edge spacer core. In this case, the coating core (120) may include an electrode slurry channel (129) extending between the first edge spacer core and the center spacer core, and an electrode slurry channel (129) extending between the second edge spacer core and the center spacer core.

[0055] In exemplary embodiments, in the coating core (120), a plurality of spacer cores (140) may each be separated from the body core (130).

[0056] In exemplary embodiments, in the coating shim (120), at least one of the plurality of spacer shims (140) may be integral with the body shim (130). For example, a first edge spacer shim may be integral with one of a pair of side bodies (133), a second edge spacer shim may be integral with the other of the pair of side bodies (133), and a center spacer shim may be integral with the center body (131). When the center spacer shim is integral with the center body (131), the coating shim (120) may include a portion extending in the second direction (D2) from above the manifold (113) to connect the center spacer shim and the center body (131). In exemplary embodiments, the coating shim (120) may have a single integrated structure in which the body shim (130) and the plurality of spacer shims (140) are integral with each other.

[0057] The flow control block (160) may be coupled to the coating die (110). For example, the flow control block (160) may be fitted to the coating die (110) or may be fastened to the coating die (110) by a fastening member such as a bolt. The flow control block (160) may be connected to an outer surface of the coating die (110) facing the substrate (510) and may include a portion extending from the outer surface of the coating die (110) toward the substrate (510) or the coating roll (150). The distance (A2) between the end of the flow control block (160) and the substrate (510) may be smaller than the distance (A1) between the end of the electrode slurry discharge port (114) and the substrate (510). Alternatively, the distance between the end of the flow control block (160) and the coating roll (150) may be smaller than the distance between the end of the electrode slurry discharge port (114) and the coating roll (150). The flow control block (160) may be spaced apart from the electrode slurry discharge port (114) in the third direction (D3) or the transport direction (TD) of the substrate (510), and the flow control block (160) may be overlapped at the center of the electrode slurry discharge port (114) in the third direction (D3) or the transport direction (TD) of the substrate (510). The width of the flow control block (160) along the first direction (D1) may be smaller than the width of the electrode slurry discharge port (114) along the first direction (D1).

[0058] The flow rate control block (160) can locally control the flow rate of the electrode slurry (520) discharged from the coating die (110), thereby locally controlling the thickness of the electrode slurry layer (521) applied on the substrate (510). The flow rate control block (160) can be placed in the flow path of the electrode slurry layer (521) so as to physically interfere with the electrode slurry layer (521) applied on the substrate (510). The flow rate control block (160) can interfere with and contact only a portion of the electrode slurry layer (521). The flow rate of the electrode slurry (520) in the region where the flow rate control block (160) is placed becomes smaller than the flow rate of the electrode slurry (520) in the peripheral region around the flow rate control block (160) in the first direction (D1). Accordingly, the thickness of the electrode slurry layer (521) in the area where the flow control block (160) is placed can be smaller than the thickness of the electrode slurry layer (521) in the peripheral area around the flow control block (160) in the first direction (D1).

[0059] The coating device (10) may include a plurality of flow rate control blocks (160), and the plurality of flow rate control blocks (160) may each correspond to a plurality of electrode slurry discharge ports (114). The plurality of flow rate control blocks (160) may each overlap in a third direction (D3) at the center of a corresponding electrode slurry discharge port (114) among the plurality of electrode slurry discharge ports (114), and may be spaced apart from the center of the corresponding electrode slurry discharge port (114) in the third direction (D3). The plurality of flow rate control blocks (160) may each be arranged in a flow path of an electrode slurry layer (521) formed from electrode slurry (520) discharged from a corresponding electrode slurry discharge port (114).

[0060] In exemplary embodiments, the flow control block (160) may be inserted into a groove (117) provided in a first die (111) of a coating die (110). The flow control block (160) may include a connecting portion (163) inserted into the groove (117) of the first die (111) and a protrusion (161) protruding from the first die (111).

[0061]

[0062] (Example 2)

[0063] Fig. 6 is a cross-sectional view showing a coating device (10) according to exemplary embodiments.

[0064] Referring to FIG. 6 together with FIG. 2, the coating device (10) may include an actuator (181) configured to move the flow control block (160). The actuator (181) may be mounted, for example, on the coating die (110). The actuator (181) may include a motor, a pneumatic cylinder, a hydraulic cylinder, or a combination thereof.

[0065] In exemplary embodiments, the actuator (181) may be configured to move the flow control block (160) in the second direction (D2) to adjust the distance (PD) by which the flow control block (160) protrudes from the coating die (110) or the distance (A2) between the flow control block (160) and the substrate (510). By adjusting the position of the flow control block (160) along the second direction (D2), the thickness of the electrode slurry layer (521) in the region of the electrode slurry layer (521) that comes into contact with the flow control block (160) may be adjusted.

[0066] In exemplary embodiments, the actuator (181) can move the flow control block (160) in a first direction (D1) to adjust the position of the flow control block (160) along the first direction (D1). The actuator (181) can move the flow control block (160) along a groove (117) of the first die (111) extending in a direction parallel to the width direction of the electrode slurry discharge port (114). By adjusting the position of the flow control block (160) along the first direction (D1), the contact position between the flow control block (160) and the electrode slurry layer (521) can be adjusted.

[0067]

[0068] (Example 3)

[0069] Fig. 7 is a cross-sectional view showing a coating device (10) according to exemplary embodiments.

[0070] Referring to FIG. 7, the actuator (181) can be configured to move the flow control block (160) in a first direction (D1), a second direction (D2), and a third direction (D3). The groove (118) of the first die (111) can provide a space in which the flow control block (160) or the rod connecting the flow control block (160) and the actuator (181) can move a certain distance in the first direction (D1), the second direction (D2), and the third direction (D3). The actuator (181) can move the flow control block (160) in the third direction (D3), thereby adjusting the distance between the flow control block (160) and the electrode slurry discharge port (114). By adjusting the position of the flow control block (160) along the third direction (D3), the position along the third direction (D3) at which contact between the flow control block (160) and the electrode slurry layer (521) is initiated can be adjusted.

[0071]

[0072] (Example 4)

[0073] Fig. 8 is a perspective view showing a coating device (10A) according to exemplary embodiments. Fig. 9 is a cross-sectional view showing a coating device (10A) according to exemplary embodiments.

[0074] Referring to FIGS. 8 and 9, the coating device (10A) may include a plurality of pressure rods (183) mounted on a coating die (110). A second portion (1113) of a first die (111) may have a plurality of holes (1115) for receiving the plurality of pressure rods (183). The plurality of holes (1115) may be spaced apart from each other along a first direction (D1), and each of the plurality of holes (1115) may communicate with a groove (117) of the first die (111). Each pressure rod (183) may be inserted into a corresponding hole (1115) among the plurality of holes (1115), and an upper end of each pressure rod (183) may be brought into contact with the first portion (1111) of the first die (111). Each of the pressure rods (183) may be configured to be moved by an actuator and configured to pressurize and support the first portion (1111) of the first die (111). The direction in which the individual pressure rods (183) pressurize the first portion (1111) of the first die (111) may be from the first die (111) toward the second die (112) or may be opposite to the transport direction (TD) of the substrate (510). By pressing the first portion (1111) of the first die (111) with a plurality of pressure rods (183), the gap between the first die (111) and the second die (112) and / or the flatness of the surface of the first die (111) facing the second die (112) may be controlled.

[0075]

[0076] (Example 5)

[0077] FIGS. 10 and 11 are cross-sectional views illustrating a method for manufacturing an electrode assembly (600) according to exemplary embodiments. Hereinafter, a method for manufacturing an exemplary electrode assembly (600) will be described with reference to FIGS. 10 and 11 together with FIGS. 1 to 5.

[0078] Referring to Fig. 10, a coating process is performed to form an electrode structure (550). The coating process can be performed in the coating device (10) described with reference to Figs. 1 to 5. The coating device (10) can spray electrode slurry (520) and insulating liquid (530) toward a substrate (510) moving by a coating roll (150), thereby applying an electrode slurry layer (521) and an insulating layer (531) on the substrate (510).

[0079] The coating process may include forming an electrode slurry layer (521) and an insulating layer (531) on each of the first and second surfaces of the substrate (510). The coating process may include a first coating process of applying the electrode slurry layer (521) and the insulating layer (531) on the first surface of the substrate (510) and a second coating process of applying the electrode slurry layer (521) and the insulating layer (531) on the second surface of the substrate (510). The electrode structure (550) may include a plurality of electrode slurry layers (521) applied on a first surface of a substrate (510), a plurality of insulating layers (531) covering both sides of each of the plurality of electrode slurry layers (521) applied on the first surface of the substrate (510), a plurality of electrode slurry layers (521) applied on a second surface of the substrate (510), and a plurality of insulating layers (531) covering both sides of each of the plurality of electrode slurry layers (521) applied on the second surface of the substrate (510).

[0080] In the electrode structure (550), a semi-coating portion (523) having a relatively small thickness may be provided at the center of each electrode slurry layer (521). The semi-coating portion (523) may be provided at the center of the electrode slurry layer (521) and may include a groove that extends continuously along the longitudinal direction (e.g., Y direction) of the electrode structure (550). During a coating process using the coating device (10), the flow rate control block (160) may interfere with the center of the electrode slurry layer (521) to reduce the flow rate of the electrode slurry (520) constituting the center of the electrode slurry layer (521). As the flow rate of the electrode slurry (520) constituting the center of the electrode slurry layer (521) is relatively reduced compared to its periphery by the flow rate control block (160) during the coating process, the electrode slurry layer (521) may have the semi-coating portion (523) at the center.

[0081] After the coating process, a drying process is performed on the electrode slurry layer (521) and the insulating layer (531) of the electrode structure (550), and a slitting process is performed to cut the electrode structure (550) along cutting lines (CL). The cutting lines (CL) may include cutting lines (CL) that cross the semi-coated portion (523) of each electrode slurry layer (521) in the longitudinal direction (e.g., Y direction) of the substrate (510). During the slitting process, each electrode slurry layer (521) may be cut along the cutting lines (CL) that extend along the semi-coated portion (523) of each electrode slurry layer (521). As a result of the slitting process, the electrode structure (550) may be separated into a plurality of anodes (610).

[0082] Referring to FIG. 11, a cathode (620), a separator (630), and an anode (610) are stacked in a vertical direction (e.g., Z direction) to form an electrode assembly (600).

[0083] The anode (610) may include an electrode slurry layer (521) and an insulating layer (531) applied on the first and second surfaces of the substrate (510), respectively. The anode (610) may include a first end (610E1) including an electrode tab (511) and a second end (610E2) opposite to the first end (610E1). At the second end (610E2) of the anode (610), the electrode slurry layer (521) may have a semi-coated portion (523). The thickness of the semi-coated portion (523) of the electrode slurry layer (521) may be smaller than the thickness of the central portion of the electrode slurry layer (521). The cathode (620) may include an electrode slurry layer (623) and an insulating layer (625) applied on the first and second surfaces of the substrate (621), respectively. The cathode (620) may include a first end (620E1) including an electrode tab (622) and a second end (620E2) opposite to the first end (620E1). A separator (630) may be interposed between the cathode (610) and the anode (620). In the electrode assembly (600), a first end (620E1) of a cathode (620) including an electrode tab (622) may face a second end (610E2) of a cathode (610) including a semi-coated portion (523), and the second end (620E2) of the cathode (620) may face a first end (610E1) of a cathode (610) including an electrode tab (511).

[0084] In the electrode assembly according to the comparative example, the electrode slurry layer of the negative electrode at the first end of the negative electrode including the electrode tab may have a sliding region having a relatively small thickness, and the electrode slurry layer of the positive electrode at the second end of the positive electrode facing the first end of the negative electrode may have a thickness substantially the same as the thickness of the central portion thereof. In this case, there is a concern that an NP ratio inversion phenomenon, in which the NP ratio becomes less than 1, may occur in the region of the electrode assembly where the first end of the negative electrode including the electrode tab and the second end of the positive electrode face each other.

[0085] In the electrode assembly (600) according to exemplary embodiments, the electrode slurry layer (521) of the positive electrode (610) provided on the second end (610E2) of the positive electrode (610) facing the first end (620E1) of the negative electrode (620) including the electrode tab (622) may include a semi-coated portion (523) having a relatively small thickness. Accordingly, in the region of the electrode assembly (600) where the first end (620E1) of the negative electrode (620) including the electrode tab (622) and the second end (610E2) of the positive electrode (610) face each other, the NP ratio inversion phenomenon can be prevented from occurring. Since the NP ratio inversion phenomenon can be prevented in the electrode assembly (600), lithium ion precipitation can be prevented during charge and discharge, and the safety and reliability of the secondary battery including the electrode assembly (600) can be improved.

[0086] According to exemplary embodiments of the present invention, the coating device includes a flow rate control block configured to locally reduce the flow rate of electrode slurry discharged from the coating die, so that the electrode slurry layer formed by applying the electrode slurry on a substrate can be formed to have a semi-coated portion having a relatively small thickness at its center.

[0087] According to exemplary embodiments of the present invention, in an electrode assembly manufactured by stacking a positive electrode and a negative electrode, the end of the positive electrode facing the end of the negative electrode including the electrode tab has a semi-coated portion having a relatively small thickness, thereby preventing the phenomenon of NP ratio reversal in the electrode assembly. Accordingly, lithium ion precipitation can be prevented during charge and discharge, and the safety and reliability of a secondary battery including the electrode assembly can be improved.

[0088] The present invention has been described in more detail through drawings and examples. However, the configurations described in the drawings or examples described in this specification are merely embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that various equivalents and modified examples may exist as of the time of this application.

Claims

1. A coating die configured to discharge electrode slurry toward a substrate and including an electrode slurry discharge port for discharging the electrode slurry; and A flow control block connected to the outer surface of the coating die facing the substrate and extending from the outer surface of the coating die toward the substrate; Including, The above flow control block is spaced apart from the electrode slurry discharge port, A coating device wherein the width of the above flow control block is smaller than the width of the above electrode slurry discharge port.

2. In paragraph 1, A coating device, characterized in that the distance between the flow control block and the substrate is smaller than the distance between the electrode slurry discharge port of the coating die and the substrate.

3. In paragraph 1, The electrode slurry discharged from the coating die forms an electrode slurry layer applied on the substrate, A coating device characterized in that the flow control block is positioned on the flow path of the electrode slurry layer so as to interfere with the center of the electrode slurry layer.

4. In paragraph 1, A coating device characterized in that the flow control block includes a connecting portion inserted into a groove of the coating die and a protrusion protruding from the coating die.

5. In paragraph 1, A coating device further comprising an actuator configured to move the flow control block.

6. In paragraph 5, A coating device characterized in that the actuator is configured to move the flow control block to adjust the distance at which the flow control block protrudes from the coating die.

7. In paragraph 5, A coating device characterized in that the actuator is configured to move the flow control block in a direction parallel to the width direction of the electrode slurry discharge port.

8. In paragraph 5, A coating device characterized in that the actuator is configured to move the flow control block in a direction perpendicular to the width direction of the electrode slurry discharge port.

9. In paragraph 1, The above coating die includes a first die and a second die spaced apart with the electrode slurry discharge port therebetween, The above first die, A groove extending in the width direction of the electrode slurry discharge port; and A first part and a second part spaced apart with the above groove therebetween; Including, The groove of the first die extends from one side of the first die to the other side and penetrates the first die, A coating device characterized in that the flow control block includes a connecting portion inserted into the groove of the coating die and a protrusion protruding from the coating die.

10. In paragraph 9, The second part of the first die faces the second die, A coating device characterized in that it further comprises a pressure rod arranged within the first part of the first die and configured to pressurize the second part of the first die.

11. In paragraph 1, A coating device characterized in that it further includes a coating core disposed within the coating die, communicating with the electrode slurry discharge port, and including a path for delivering the electrode slurry.

12. In paragraph 11, The above coating die is further configured to discharge an insulating liquid toward the substrate, A coating device characterized in that the coating core further includes a path for delivering the insulating liquid.

13. In paragraph 1, Further comprising a coating roll configured to transport the above-mentioned material, A coating device characterized in that the distance between the flow control block and the coating roll is smaller than the distance between the electrode slurry discharge port of the coating die and the coating roll.

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