Patent Description:
The present specification relates to an electrode manufacturing apparatus and an electrode roll.

Recently, prices of energy sources have increased because of the depletion of fossil fuels, and the interest in environmental pollution is increasing. Therefore, there is an increasing demand for environmental-friendly alternative energy sources. Therefore, research on various power production technologies such as nuclear power, solar power, wind power, and tidal power is being continuously conducted. In addition, interest in power storage devices for more efficiently using the produced energy is high.

In particular, as the development of technologies and demands for mobile devices are increased, there is a rapidly increasing demand for batteries as energy sources. Many studies are being conducted on the batteries in order to meet these needs.

Representatively, regarding a shape of the battery, there is a high demand for an angular or pouch-type secondary battery that may have a small thickness and be applied to products such as mobile phones. Regarding a material, there is a high demand for lithium secondary batteries such as lithium-ion batteries or lithium-ion polymer batteries that have advantages such as a high energy density, a discharge voltage, and output stability.

In general, the secondary battery is structured to include an electrode assembly made by stacking a positive electrode, a negative electrode, and a separator positioned between the positive electrode and the negative electrode. The positive and negative electrodes are each manufactured by applying slurry containing an active material onto a current collector. The manufactured electrode is stored in a state of being wound around a bobbin before assembling the battery, and is moved when necessary.

To improve efficiency of an electrode coating process, a single current collector may be coated with a plurality of electrodes and stored by being wound around the bobbin. However, in this case, a portion of the current collector, which is disposed between the electrodes and is not coated with slurry, may be wrinkled. Accordingly, there is a need for a method capable of solving a problem with storage. <CIT>, <CIT>, and <CIT> are further prior art.

The present specification is intended to provide an electrode manufacturing apparatus and an electrode roll.

One embodiment of the present specification provides an electrode manufacturing apparatus including: a supply part configured to supply a substrate; a coating part configured to coat at least one surface of the supplied substrate with an electrode layer divided into coated portions coated with electrode slurry and provided in two or more regions spaced apart from one another in a direction perpendicular to a direction in which the substrate is supplied, and a non-coated portion between the coated portions in the two or more regions; a drying part configured to dry the coated electrode layer to manufacture an electrode film; and a recovery part configured to recover the electrode film, in which the recovery part includes: a bobbin around which the electrode film is wound; and a variable ring fitted with the bobbin and configured to be movable in a longitudinal direction of the bobbin, the variable ring being provided to correspond to a position of the non-coated portion.

In an embodiment of the present specification, the variable ring may be an elastic band.

In another embodiment of the present specification, a width of the variable ring may be <NUM> or more times and less than <NUM> time a width of the non-coated portion.

In yet another embodiment of the present specification, a thickness of the variable ring may be <NUM> or more and <NUM> or less.

In an embodiment of the present specification, the coating part may coat at least one surface of the supplied substrate with the electrode layer divided into the coated portions coated with the electrode slurry and provided in the two regions spaced apart from each other in the direction perpendicular to the direction in which the substrate is supplied, and the non-coated portion between the coated portions in the two regions, and the recovery part may include a single variable ring provided to correspond to a position of the non-coated portion.

In an embodiment of the present specification, the coating part may coat at least one surface of the supplied substrate with the electrode layer divided into the coated portions coated with the electrode slurry and provided in the three regions spaced apart from one another in the direction perpendicular to the direction in which the substrate is supplied, and the two non-coated portions respectively positioned between the coated portions in the three regions, and the recovery part may include two variable rings provided to respectively correspond to positions of the two non-coated portions.

Another embodiment of the present specification provides an electrode roll including: an electrode film including a substrate, and an electrode layer disposed on at least one surface of the substrate and divided into coated portions coated with electrode slurry and provided in two or more regions spaced apart from one another in a longitudinal direction of the substrate, and a non-coated portion provided between the two or more coated portions; a bobbin around which the electrode film is wound; and a variable ring fitted with the bobbin and configured to be movable in a longitudinal direction of the bobbin, the variable ring being provided to correspond to the position of the non-coated portion.

In an embodiment of the present specification, the electrode layer may be disposed on at least one surface of the substrate and divided into the coated portions disposed in the two regions spaced apart from each other in the longitudinal direction of the substrate, and the non-coated portion provided between the coated portions in the two regions, and the variable ring may be provided to correspond to a position of the non-coated portion.

In an embodiment of the present specification, the electrode layer may be disposed on at least one surface of the substrate and divided into the coated portions provided in the three regions spaced apart from one another in the longitudinal direction of the substrate, and the two non-coated portions respectively provided between the coated portions in the three regions, and the variable rings may be provided to respectively correspond to positions of the two non-coated portions.

An embodiment of the present specification may advantageously reduce wrinkles that may occur between the plurality of electrodes formed on the single substrate.

An embodiment of the present specification may advantageously reduce the thickness difference between the non-coated portion and the coated portion coated with the electrode.

An embodiment of the present specification may advantageously reduce differences in physical characteristics between the non-coated portion and the coated portion coated with the electrode.

However, the drawings are intended to illustratively describe the present invention, and the scope of the present invention is not limited by the drawings.

<FIG> is a block diagram illustrating an electrode manufacturing apparatus <NUM> according to an embodiment of the present specification, and <FIG> is a cross-sectional view illustrating the electrode manufacturing apparatus <NUM> according to an embodiment of the present specification. The electrode manufacturing apparatus <NUM> includes a supply part <NUM>, a coating part <NUM>, a drying part <NUM>, and a recovery part <NUM>.

The recovery part <NUM> includes: a bobbin <NUM> around which the electrode film <NUM> is wound; and a variable ring fitted with the bobbin <NUM> and configured to be movable in a longitudinal direction of the bobbin <NUM>, the variable ring being provided to correspond to a position of a non-coated portion <NUM> provided between coated portions <NUM> of an electrode film that are coated with electrode slurry.

As illustrated in <FIG>, in case that an electrode film <NUM>, which has a non-coated portion <NUM> provided between coated portions coated with electrode slurry, is wound around a bobbin having no variable ring, the indicated portion, i.e., the non-coated portion is wrinkled after a winding operation is completed, as illustrated in <FIG>, as in Cases <NUM> to <NUM> illustrated in <FIG>. When the coated electrode is dried and then finally wound, the non-coated portion, which is mainly disposed at a center of the electrode, is wrinkled because of a thickness difference between the coated portion and the non-coated portion. A degree to which the wrinkle is formed increases as a thickness of a foil, which is a substrate, decreases, the amount of coating on the electrode relatively increases, and a thickness of the coated portion increases.

In contrast, as illustrated in <FIG>, in case that a variable ring <NUM> is provided to correspond to a position of the non-coated portion <NUM> provided between the coated portions <NUM> of the electrode film that are coated with the electrode slurry, a level difference between the non-coated portion <NUM> and the coated portion <NUM> coated with the electrode decreases, thereby reducing the occurrence of wrinkles.

The variable ring <NUM> may be a ring made of an elastic material, specifically, an elastic band. The material is not particularly limited as long as the material has appropriate rubber elasticity and mechanical strength, excellent wear resistance, and a small frictional coefficient. Rubber such as urethane rubber, natural rubber, acrylic rubber, or the like may be used as the material. In this case, the variable ring <NUM> provides an elastic force, such that the variable ring <NUM> may be easily moved in accordance with a position of the non-coated portion <NUM> of the electrode film, which is a recovery target, and the variable ring <NUM> is positioned to be in close contact with a surface of a bobbin after being moved, such that a designated position is not easily changed during the process. In addition, the variable ring may be deformed in shape by a force. Therefore, even though the amount of force applied to a center of the bobbin is increased by the electrode film wound in multiple layers, the variable ring may cope with the increase in force while being appropriately deformed in shape.

A width W of the variable ring <NUM> may be <NUM> or more times and less than <NUM> time, <NUM> or more times and less than <NUM> time, <NUM> or more times and less than <NUM> time, <NUM> or more times and less than <NUM> time, <NUM> or more times and less than <NUM> time, <NUM> or more times and less than <NUM> time, <NUM> or more times and less than <NUM> time, <NUM> or more times and less than <NUM> time, or <NUM> or more times and less than <NUM> time a width of the non-coated portion <NUM>. A width of the variable ring <NUM> may be almost equal to a width of the non-coated portion <NUM>. However, in case that the width of the variable ring <NUM> is equal to or larger than the width of the non-coated portion <NUM>, the variable ring <NUM> may come into contact with an edge of the coated portion <NUM> and deform the coated portion <NUM>. When the above-mentioned range is satisfied, the width of the variable ring <NUM> compensates for a level difference from the coated portion <NUM> without deforming the coated portion <NUM>.

A thickness H of the variable ring <NUM> may be selected in consideration of a height of the coated portion <NUM>. Specifically, the thickness H of the variable ring <NUM> may be <NUM> or more and <NUM> or less, or <NUM> or more and <NUM> or less. In this case, the thickness H of the variable ring may be implemented by the single variable ring, as illustrated in <FIG>. Alternatively, as illustrated in <FIG>, the target thickness H (H=H1+H2) of the variable ring may be implemented by stacking two or more variable rings, i.e., stacking a first variable ring <NUM>' having a thickness of H1 and a second variable ring <NUM>" having a thickness of H2.

A shape of the bobbin <NUM> is not particularly limited as long as the electrode film may be stored or moved in a state of being wound around the bobbin <NUM>. The bobbin <NUM> may have a cylindrical shape.

The bobbin <NUM> may have a shape similar to a shape of a spool. In this case, a central portion of the bobbin <NUM> around which the electrode film <NUM> is wound has a constant diameter, and two opposite ends of the bobbin <NUM> each have a larger diameter than the central portion of the bobbin <NUM>, which makes it possible to prevent the electrode film <NUM> wound around the central portion of the bobbin <NUM> from being separated toward the two opposite ends of the bobbin <NUM>.

A length of the bobbin <NUM> is not particularly limited as long as the length of the bobbin <NUM> is larger than a width of the electrode film <NUM> and there is no problem occurring when the electrode film <NUM> is stored.

A diameter of the bobbin <NUM> is not particularly limited as long as the bobbin <NUM> may withstand a physical force applied by the wound electrode film <NUM> when the electrode film <NUM> is stored.

<FIG> is a cross-sectional view illustrating an electrode manufacturing apparatus according to still yet another embodiment of the present specification. The electrode manufacturing apparatus <NUM> further includes a cutting part <NUM> in addition to the supply part <NUM>, the coating part <NUM>, the drying part <NUM>, and the recovery part <NUM>.

The cutting part <NUM> has a cutter. The cutter may separate a manufactured electrode into two or more pieces by cutting the non-coated portion in a supply direction. The recovery parts <NUM> may be provided to correspond in number to the two or more electrodes separated as described above.

A facility for manufacturing the electrode having a large width of <NUM> or more, <NUM> or more, or <NUM> or more is advantageous in mass-producing the electrode. However, in case that the single recovery part <NUM> is provided to correspond in width to the manufactured electrode having a large width, the number of non-coated portions is inevitably increased in a direction perpendicular to the supply direction, and the number of defects is inevitably increased because of a thickness difference between the coated portion and the non-coated portion.

Before the manufactured electrode having a large width is wound around the recovery part <NUM> at a distal end of the facility, the cutting part <NUM> cuts the manufactured electrode having a large width into a width that may allow the variable ring <NUM> provided on the recovery part <NUM> to control a defect caused by a thickness difference between the coated portion and the non-coated portion. The plurality of recovery parts <NUM> may be provided to correspond in number to the cut electrodes.

<FIG> is a perspective view illustrating a state in which the cutting part <NUM> is provided according to another embodiment of the present specification, and <FIG> is a cross-sectional view illustrating a state in which the cutting part <NUM> is provided according to another embodiment of the present specification.

The cutting part <NUM> may have two knife wheels <NUM> and <NUM> that may cut the electrode while rotating when the electrode moves between the two knife wheels <NUM> and <NUM>. The cutting part <NUM> may include a lower knife <NUM> provided below the substrate <NUM>, and an upper knife <NUM> provided above the substrate <NUM>. The upper knife <NUM> and the lower knife <NUM> may respectively include the knife wheel <NUM> and <NUM>, and housings <NUM> and <NUM> into which the knife wheel is respectively inserted and fixed.

Any one of the two knife wheels <NUM> and <NUM> may rotate in the same rotation direction as adjacent guide rolls <NUM> and <NUM>', and the other of the two knife wheels <NUM> and <NUM> may rotate in a direction opposite to the rotation direction of the adjacent guide rolls <NUM> and <NUM>'.

The rotation directions of the two knife wheels <NUM> and <NUM> may be different from each other, but the rotational speeds of the two knife wheels <NUM> and <NUM> may be equal to each other. More specifically, the rotational speeds of the two knife wheels <NUM> and <NUM> may each be equal to a rotational speed of each of the guide rolls <NUM> and <NUM>'.

The supply part <NUM> serves to supply the substrate <NUM>. The configuration for supplying the substrate is not particularly limited as long as the supply part <NUM> may supply the substrate <NUM>. The supply part <NUM> may supply the substrate <NUM> by unwinding the substrate <NUM> from a roll around which the substrate <NUM> is wound.

In this case, the substrate <NUM> is not particularly limited as long as the substrate may be coated with electrode slurry. The substrate <NUM> may be a current collector, specifically, a metal foil. The substrate may be a foil made of copper, aluminum, or a combination thereof.

The coating part <NUM> coats at least one surface of the supplied substrate <NUM> with the electrode layer divided into the coated portions <NUM> coated with the electrode slurry and provided in two or more regions spaced apart from one another in the direction perpendicular to the direction in which the substrate <NUM> is supplied, and the non-coated portions <NUM> disposed between the coated portions provided in the two or more regions.

A method of coating electrode slurry by the coating part <NUM> is not particularly limited. A general method of applying electrode slurry using a slot die, a blade, comma coating, or the like may be selected and changed, as necessary.

The electrode slurry, which is to be coated by the coating part <NUM>, may include an electrode active material, a binder, and a solvent.

The electrode active material is not particularly limited as long as the electrode active material is a material used for a positive electrode or a negative electrode of a battery. The electrode active material may be a cobalt-based active material, a ternary active material, a nickel-based active material, a manganese-based active material, a phosphoric acid-based active material, or the like.

The binder is not particularly limited as long as the binder may coagulate the electrode active material. The binder may be polyvinylidene fluoride, styrene-butadiene rubber (SBR), or the like.

The solvent is not particularly limited as long as the solvent may provide fluidity to the electrode slurry. The solvent may be water, N-methyl pyrrolidone, or the like.

The drying part <NUM> removes the solvent in the coated electrode slurry by drying the coated electrode layer.

A drying means of the drying part <NUM> is not particularly limited. However, the drying means of the drying part <NUM> may be selected in accordance with characteristics of the electrode slurry that is a target to be dried. At least one of hot blast, a heater, and UV irradiation may be selected.

A drying temperature and time of the drying part <NUM> are not particularly limited. However, the drying temperature and time of the drying part <NUM> may be adjusted depending on characteristics of the electrode slurry that is a target to be dried. For example, the electrode slurry may be dried at a temperature of about <NUM> or less for <NUM> seconds to <NUM> minutes.

In an embodiment, as illustrated in <FIG>, the coating part <NUM> may coat at least one surface of the supplied substrate with the electrode layer <NUM> divided into the coated portions <NUM> coated with the electrode slurry and provided in the two regions spaced apart from each other in the direction perpendicular to the direction in which the substrate is supplied, and the non-coated portion <NUM> disposed between the coated portions in the two regions. The recovery part <NUM> may include the single variable ring <NUM> provided to correspond to the position of the non-coated portion <NUM>.

In another embodiment, as illustrated in <FIG>, the coating part <NUM> may coat at least one surface of the supplied substrate with the electrode layer <NUM> divided into the coated portions <NUM> coated with the electrode slurry and provided in the three regions spaced apart from one another in the direction in which the substrate is supplied, and the two non-coated portions <NUM> positioned between the coated portions provided in the three regions. The recovery part <NUM> may include the two variable rings <NUM> provided to correspond to the positions of the two non-coated portions.

Still another embodiment of the present specification provides an electrode roll including: an electrode film including a substrate, and an electrode layer disposed on at least one surface of the substrate and divided into coated portions coated with electrode slurry and provided in two or more regions spaced apart from one another in a longitudinal direction (supply direction) of the substrate, and non-coated portions provided between the two or more coated portions; a bobbin around which the electrode film is wound; and a variable ring fitted with the bobbin and configured to be movable in a longitudinal direction of the bobbin, the variable ring being provided to correspond to the position of the non-coated portion.

In this case, the description of the electrode roll may be replaced with the description of the electrode manufacturing apparatus.

In an embodiment, as illustrated in <FIG>, the electrode layer <NUM> may be disposed on at least one surface of the substrate and divided into the coated portions <NUM> provided in the two regions spaced apart from each other in the longitudinal direction of the substrate, and the non-coated portion <NUM> provided between the coated portion provided in the two regions. The variable ring <NUM> may be provided to correspond to the position of the non-coated portion <NUM>.

In another embodiment, as illustrated in <FIG>, the electrode layer <NUM> may be disposed on at least one surface of the substrate and divided into the coated portions <NUM> provided in three regions spaced apart from one another in the longitudinal direction of the substrate, and the two non-coated portions <NUM> provided between the coated portions in the three regions. The variable rings <NUM> may be provided to respectively correspond to the positions of the two non-coated portions <NUM>.

Claim 1:
An electrode manufacturing apparatus (<NUM>) comprising:
a supply part (<NUM>) configured to supply a substrate (<NUM>);
a coating part (<NUM>) configured to coat at least one surface of the supplied substrate (<NUM>) with an electrode layer (<NUM>) divided into coated portions (<NUM>), wherein the coated portions (<NUM>) are coated with an electrode slurry positioned in two or more regions spaced apart from one another in a direction perpendicular to a direction in which the substrate (<NUM>) is supplied, and a non-coated portion (<NUM>) positioned between the coated portions (<NUM>);
a drying part (<NUM>) configured to dry the electrode slurry to manufacture an electrode film (<NUM>); and
a recovery part (<NUM>) configured to recover the electrode film (<NUM>),
characterised in that
the recovery part (<NUM>) comprises:
a bobbin (<NUM>) around which the electrode film (<NUM>) is wound; and
a variable ring (<NUM>) fitted with the bobbin (<NUM>) and configured to be movable in a longitudinal direction of the bobbin (<NUM>), the variable ring (<NUM>) positioned to correspond to a position of the non-coated portion (<NUM>).