Patent Description:
With the increase in technology development and demand for mobile devices, the demand for secondary batteries is also rapidly increasing. Among them, lithium secondary batteries are widely used as an energy source for various electronic products as well as various mobile devices because of their high energy density and high operating voltage and excellent storage and lifetime characteristics.

In recent years, as the field of application for secondary batteries expands, the demand for higher-capacity secondary batteries (e.g., for electric vehicles) is also increasing rapidly.

A secondary battery includes an electrode assembly composed of a positive electrode, a negative electrode and a separator (i.e., separation membrane) interposed therebetween. In general, the positive electrode and the negative electrode are each formed by coating an electrode active material onto a current collector of an electrode substrate. In order to construct the positive electrode and the negative electrode as a good-quality electrode, problems such as folding or wrinkles should not occur on the current collector even after the electrode active material is coated onto the current collector of the electrode substrate.

<CIT> discloses a manufacturing apparatus of electrode for a secondary battery. Document <CIT> discloses a manufacturing apparatus of an electrode for a secondary battery comprising a transfer unit that transfers an electrode sheet coated with an electrode active material layer from an unwinder; a rolling unit that is arranged on the transfer unit and rolls the electrode active material layer composed of the electrode active material; and a pressing unit that is arranged adjacently to the rolling unit and presses the non-coated part of the current collector to which the electrode active material is not applied, wherein the pressing unit comprises, a roll member; and a ring assembly that is detachably coupled to the roll member and comes into contact with the non-coated part to press the non-coated part.

The present disclosure has been designed to solve the above-mentioned problems, and an object of the present disclosure is to provide a manufacturing apparatus of an electrode for a secondary battery which can prevent occurrence of defects on a non-coated part of an electrode substrate during a manufacturing process of an electrode for a secondary battery.

The objects of the present disclosure are not limited to the aforementioned objects, and other objects which are not mentioned herein should be clearly understood by those skilled in the art from the following detailed description and the accompanying drawings.

According to the present invention, there is provided a manufacturing apparatus of an electrode for a secondary battery as defined in the appended set of claims. The manufacturing apparatus comprises a transfer unit that transfers a current collector from an unwinder; a coating unit that applies an electrode active material to at least one surface of the current collector; a rolling unit that is arranged on the transfer unit and rolls the electrode active material layer composed of the electrode active material; and a pressing unit that is arranged adjacently to the rolling unit and presses the non-coated part of the current collector to which the electrode active material is not applied, wherein the pressing unit includes a roll member; and a ring assembly that is detachably coupled to the roll member and comes into contact with the non-coated part to press the non-coated part.

The ring assembly includes a first ring member that is detachably fixed to the roll member; and a second ring member that has a larger diameter than the first ring member and is connected to the first ring member to press the pressing unit.

A third ring member having an elastic force may be coupled to an outer peripheral surface of the second ring member, and the third ring member may be a rubber.

A depressed part is formed on the inner surface of the third ring member, and a protrusion part is formed on the outer peripheral surface of the second ring member, and the protrusion part of the second ring member may be fitted into the depressed part of the third ring member.

The first ring member is made in a form in which both ends are formed as free ends, and extension parts each extending from both ends may be provided with an opening for screw coupling.

The respective extension parts have a length greater than the width of the first ring member and may be arranged parallel to the roll member.

The first ring member may be rotatably coupled to the second ring member.

The respective extension parts may extend vertically from both ends.

A width of the second ring member may be formed to be smaller than a width of the non-coated part.

Both ends of the roll member are connected to an elevation arm and a cylinder, respectively, so that the roll member can be displaced with respect to the current collector.

The ring assembly is arranged at equal intervals on the roll member and may be provided by plural numbers.

The pressing unit may be arranged at the front and rear ends of the rolling unit, respectively.

The pressing unit may be configured so as to press the non-coated part of the first surface of the current collector and the non-coated part of the second surface opposing to the first surface, respectively.

A manufacturing apparatus of an electrode for a secondary battery according to the present disclosure can press the non-coated part with a ring assembly rotating by a roll member in the process of manufacturing electrodes for secondary batteries, and prevent defects that cause wrinkles on the non-coated part, thereby increasing the efficiency of the manufacturing process and providing a good-quality electrode.

The present disclosure will be described in more detail below. Prior to the description, the terms or words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the present disclosure should be construed with meanings and concepts that are consistent with the technical idea of the present disclosure based on the principle that the inventors may appropriately define concepts of the terms to appropriately describe their own disclosure in the best way.

<FIG> is a schematic diagram showing an electrode manufacturing apparatus according to one embodiment of the present disclosure. <FIG> is a partial perspective view showing an electrode manufacturing apparatus according to one embodiment of the present disclosure. As shown in <FIG>, the electrode manufacturing apparatus <NUM> includes a roller-shaped unwinder <NUM> in which a sheet-shaped current collector <NUM> made of a metal material (e.g., copper) for a positive electrode or a negative electrode of a secondary battery is wound.

The current collector <NUM> unwound from the unwinder <NUM> is transferred along one direction (from left to right with reference to <FIG>) by the transfer unit <NUM> of the electrode manufacturing apparatus <NUM>. Here, the transfer unit <NUM> may include a plurality of rolls.

The electrode active material <NUM> is applied (coated) onto the current collector <NUM>, which is transferred by the transfer unit <NUM>, by using the coating unit <NUM> of the electrode manufacturing apparatus <NUM>, and the coated electrode active material <NUM> is dried through the drying unit <NUM> of the electrode manufacturing apparatus <NUM>.

The electrode active material layer <NUM> dried by the drying unit <NUM> is rolled by the rolling unit <NUM> of the electrode manufacturing apparatus <NUM>, and the current collector <NUM> including the rolled electrode active material layer <NUM> is wound around a winder <NUM> of the electrode manufacturing apparatus <NUM>.

In the present embodiment, the coating unit <NUM> may include a coating die <NUM> that flows out the electrode active material <NUM> toward the current collector <NUM>, and a coater roll <NUM> that is arranged so as to face the coating die <NUM> with the current collector <NUM> being interposed therebetween to apply tension to the current collector <NUM>.

In the present embodiment, the coating of the electrode active material <NUM> by the coating unit <NUM> may be performed such that a plurality of electrode active material layers <NUM> are provided on the current collector <NUM>. Referring to <FIG>, the current collector <NUM> is provided with three rows of electrode active material layers <NUM>, wherein a non-coated part <NUM> is maintained between the electrode active material layers <NUM> to which the electrode active material is not applied and the electrode active material layer <NUM>, and between the electrode active material layer <NUM> and the edge of the current collector <NUM>. For example, the current collector <NUM> has four rows of non-coated parts <NUM> formed therein.

Moreover, the drying unit <NUM> is configured to evaporate the solvent from the electrode active material <NUM> to form the electrode active material layer <NUM>, and the rolling unit <NUM> may include a pair of rollers <NUM> and <NUM> arranged with the current collector <NUM> interposed therebetween, and the winder <NUM> may be made in the shape of a roller.

Meanwhile, a pressing unit <NUM> that presses the non-coated part <NUM> is arranged on the current collector <NUM> adjacent to the rollers <NUM> and <NUM> serving as the rolling unit <NUM>, in order to prevent occurrence of defects such as a folding phenomenon on the non-coated part <NUM> due to the force generated when the electrode active material layer <NUM> is rolled by the rolling unit <NUM>.

The pressing unit <NUM> may be arranged at the rear end of the rolling unit <NUM> on the basis of the transfer direction of the current collector <NUM> (e.g., the arrow direction shown in <FIG> illustrates that the pressing unit <NUM> is arranged on both sides of the rolling unit <NUM>, that is, at the front and rear ends of the rolling unit <NUM>.

In the present embodiment, the pressing unit <NUM> includes a roll member <NUM> that has a predetermined diameter and length and is rotated by a driving source (not shown). In addition, the pressing unit <NUM> includes a ring assembly <NUM> that is detachably coupled to the roll member <NUM>. The ring assembly <NUM> comes into contact with the non-coated part <NUM> while rotating in conjunction with the rotation of the roll member <NUM>, and presses the non-coated part <NUM>.

<FIG> is a perspective view illustrating a pressing unit of an electrode manufacturing apparatus according to one embodiment of the present disclosure. <FIG> is a perspective view showing a modified embodiment of the pressing unit of <FIG>.

In the present embodiment, the ring assembly <NUM> of the pressing unit <NUM> includes a first ring member <NUM> and a second ring member <NUM>. The first ring member <NUM> and the second ring member <NUM> are connected to each other, and the second ring member <NUM> may have a circular shape having a larger diameter than the first ring member <NUM>.

In the case of the embodiment shown in <FIG> and <FIG>, the first ring member <NUM> and the second ring member <NUM> are fixed to each other by a connection member <NUM> disposed oppositely between the first ring member <NUM> and the second ring member <NUM>. Thereby, the first ring member <NUM> is spaced apart from the second ring member <NUM> by a distance corresponding to the length of the connection member <NUM>.

The second ring member <NUM> is formed in a complete ring shape, while the first ring member <NUM> is made in a ring form in which both ends, that is, both ends disposed on the upper side with reference to the drawing are formed as free ends. Thereby, the first ring member <NUM> can be moved by its own elastic force up to both ends while the portion connected to the connection member <NUM> is assumed as a fixed point. The extension parts <NUM> are respectively extended at both ends of the first ring member <NUM>.

The extension part <NUM> has a predetermined length and is arranged parallel to the longitudinal direction of the roll member <NUM>, the length may be larger than the width of the first ring member <NUM>, and the width may be smaller than the distance between the first ring member <NUM> and the second ring member <NUM>.

Further, the respective extension parts <NUM> are provided with an opening <NUM> for screw coupling of the coupling screw <NUM> and the nut <NUM>, respectively. That is, because the coupling screw <NUM> is inserted into the opening <NUM> of the extension part <NUM>, and coupled with the nut <NUM>, a first ring member <NUM> can be fixed to the roll member <NUM>, and the first ring member <NUM> can be spaced apart from the roll member <NUM> due to the release of the coupling screw <NUM> and the nut <NUM>. This will be explained in more detail below.

In the present disclosure, the attachment and detachment of the first ring member <NUM> to the roll member <NUM> cannot be performed only by the coupling structure of the above coupling screw and nut.

Meanwhile, a third ring member <NUM> having an elastic force may be coupled to the second ring member <NUM>. In the present embodiment, the third ring member <NUM> is provided as a rubber and coupled to the outer peripheral surface of the second ring member <NUM>. Of course, the third ring member <NUM> may be composed of a member made of other materials that can have an elastic force as well as rubber. As the third ring member <NUM> is formed of a material capable of having an elastic force such as rubber, it may help that the current collector <NUM> travels smoothly. In other words, since the third ring member <NUM> has an elastic force, it can play a role of pulling the current collector <NUM> using a frictional force during rotation in a state of being in contact with the current collector <NUM>.

Further, since the third ring member <NUM> has an elastic force, it is possible to increase the effect of applying tension to the non-coated part <NUM> and widening the wrinkles.

Furthermore, since the third ring member <NUM> has an elastic force, it can be easily coupled to the outer peripheral surface of the second ring member <NUM>. As a modified embodiment, referring to <FIG>, a protrusion part P for inserting the third ring member <NUM> is formed on the outer peripheral surface of the second ring member <NUM>, and a depressed part D into which the protrusion part P is fitted may be formed on an inner surface of the third ring member <NUM>.

Referring to <FIG> and <FIG> again, the width of the second ring member <NUM> and the width of the third ring member <NUM> may be substantially identical, and the widths of the second and third ring members <NUM> and <NUM> may be identical to or smaller than the width of the non-coated part <NUM>.

A plurality of ring assemblies <NUM> configured in this manner may be provided on the roll member <NUM>. In this embodiment, as described above, since three rows of the active material layers <NUM> and four rows of the non-coated parts <NUM> are formed on the current collector <NUM>, four ring assemblies <NUM> can be arranged on the roll member <NUM> at intervals corresponding to the width of the active material layer <NUM> in accordance with the four rows of the non-coated parts <NUM>. At this time, two ring assemblies <NUM> can be provided on the roll member <NUM>, so that the extension part <NUM> faces in the same direction (e.g., to the left with reference to <FIG>), and the other two ring assemblies <NUM> can be provided on the roll member <NUM>, so that the extension part <NUM> faces in the same other direction (e.g., to the right with reference to <FIG>).

The coupling between the ring assembly <NUM> and the roll member <NUM> is performed by inserting a coupling screw <NUM> into the opening <NUM> of the extension part <NUM> of the first ring member <NUM> and coupling a nut <NUM> thereto, in a state where the first ring member <NUM> of the ring assembly <NUM> is inserted into the roll member <NUM> and stopped at a desired position.

Due to the coupling of the coupling screw <NUM> and the nut <NUM>, the first ring member <NUM> may be fixed to the roll member <NUM>, and thus the ring assembly <NUM> can be fixed to the roll member <NUM>.

When the active material layer <NUM> is rolled by the rolling unit <NUM> during manufacturing of the secondary battery electrode, the pressing unit <NUM> comes into contact with the non-coated part <NUM> and presses the non-coated part <NUM>. That is, as the roll member <NUM> of the pressing unit <NUM> rotates, the ring assembly <NUM> rotates and presses the non-coated part <NUM>. Therefore, even if the force of rolling of the rolling unit <NUM> is transmitted to the non-coated part <NUM>, the non-coated part <NUM> can be pressed by the pressing unit <NUM> to maintain tension, thereby preventing defects such as a folding phenomenon. That is, the pressing unit <NUM> can displace the roll member <NUM> relative to the current collector <NUM> by the elevation arm <NUM> and the cylinder <NUM> connected to the roll member <NUM>, thereby adjusting the degree of tension that presses the non-coated part <NUM>.

<FIG> is a cross-sectional view showing a ring assembly of an electrode manufacturing apparatus according to another embodiment of the present disclosure.

The ring assembly <NUM>' of the other embodiment is constructed to be substantially identical to the ring assembly of the above-mentioned embodiment, while it is constructed by changing only the connection relationship between the first ring member <NUM>' and the second ring member <NUM>'.

In another embodiment, a mutual connection between the first ring member <NUM>' and the second ring member <NUM>' can rotatably couple the second ring member <NUM>' to the first ring member <NUM>' or can rotatably couple the first ring member <NUM>' to the second ring member <NUM>'.

For example, as shown in <FIG>, the connection member <NUM>' extending from the first ring member <NUM>' is rotatably coupled to the groove <NUM>" provided in the second ring member <NUM>', and the first ring member <NUM>' can be rotatably coupled to the second ring member <NUM>'.

Due to this configuration, the ring assembly <NUM>' according to another embodiment can fix the first ring member <NUM>' to the roll member <NUM>' by coupling the coupling screw <NUM>' and the nut <NUM>', even if the extension part <NUM>' extending from both ends of the first ring member <NUM>' is vertically extended from both ends between the first ring member <NUM>' and the second ring member <NUM>'.

<FIG> is a schematic diagram showing an electrode manufacturing apparatus according to another embodiment of the present disclosure.

Claim 1:
A manufacturing apparatus (<NUM>) of an electrode for a secondary battery comprising:
a transfer unit (<NUM>) that transfers a current collector from an unwinder (<NUM>);
a coating unit (<NUM>) that applies an electrode active material (<NUM>) to at least one surface of the current collector (<NUM>);
a rolling unit (<NUM>) that is arranged on the transfer unit (<NUM>) and rolls the electrode active material layer (<NUM>) composed of the electrode active material (<NUM>); and
a pressing unit (<NUM>) that is arranged adjacently to the rolling unit (<NUM>) and presses the non-coated part of the current collector (<NUM>) to which the electrode active material (<NUM>) is not applied,
wherein the pressing unit (<NUM>) comprises,
a roll member (<NUM>); and
a ring assembly (<NUM>) that is detachably coupled to the roll member (<NUM>) and comes into contact with the non-coated part to press the non-coated part, and wherein the ring assembly (<NUM>) comprises:
a first ring member (<NUM>, <NUM>') that is detachably fixed to the roll member (<NUM>); and
a second ring member (<NUM>, <NUM>') that has a larger diameter than the first ring member (<NUM>, <NUM>') and is connected to the first ring member (<NUM>, <NUM>').