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

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.

A crack is formed in a surface of the dried electrode when the humidity is not suitable for removing a solvent from the applied slurry.

Therefore, there is a need to adjust a condition for drying the slurry to prevent a crack from being formed in the electrode.

<CIT> discloses an electrode manufacturing apparatus and method according to the prior art.

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

The invention is an electrode manufacturing device according to claim <NUM> and an electrode manufacturing method according to claim <NUM>.

The electrode manufacturing device according to the invention provides an electrode manufacturing apparatus including: a supply part configured to supply an electrode precursor made by applying electrode slurry onto a substrate; a drying part configured to dry the electrode slurry to manufacture an electrode and including an air supply part configured to supply high-temperature vapor onto the electrode precursor, an air introducing part configured to introduce the supplied high-temperature vapor, a flow path connected from the air introducing part to the air supply part, a sensor configured to measure humidity of the introduced high-temperature vapor, an air discharge part configured to be opened or closed to discharge to the outside a part of the high-temperature vapor that circulates from the air introducing part toward the air supply part along the flow path, and a humidifying part configured to humidify the high-temperature vapor that circulates from the air introducing part toward the air supply part along the flow path; a discharge part configured to discharge the manufactured electrode; a monitoring part configured to monitor the electrode discharged by the discharge part; and a control part configured to collect monitoring information obtained by the monitoring part and information on the humidity measured by the sensor and control whether to open or close the air discharge part and a degree of humidification by the humidifying part; wherein the control part is configured to increase the humidity of the high temperature vapor when the monitoring part detects the crack in the electrode until no crack is detected in the electrode , and wherein the monitoring part is configured to maintain a determined humidity of the high-temperature vapor in the drying part when the monitoring part detects no crack in the electrode, wherein the control part is configured to determine the humidity when no crack is detected in the electrode.

The electrode manufacturing method according to the invention provides an electrode manufacturing method including: supplying an electrode precursor, which is made by applying electrode slurry onto a substrate, into a drying part; drying the electrode slurry to manufacture an electrode while supplying high-temperature vapor to adjust humidity in the drying part; discharging the manufactured electrode from the drying part; monitoring the discharged electrode; and collecting monitoring information obtained by the monitoring of the electrode and information on the humidity in the drying part and controlling the humidity in the drying part; wherein the controlling of the humidity in the drying part comprises: increasing the humidity in the drying part when a crack is formed in the electrode until no crack is detected in the electrode by the monitoring of the electrode ; and determining a humidity at which no crack is detected in the electrode and controlling the humidity in the drying part to maintain the humidity so as to match the humidity at which no crack is detected in the electrode.

The electrode manufacturing apparatus and the electrode manufacturing method according to the embodiment of the present specification may control optimal humidity in the drying part on the basis of information obtained by monitoring the dried electrode.

The electrode manufacturing apparatus and the electrode manufacturing method according to another embodiment of the present specification may derive and maintain optimal humidity for the drying target of electrode precursor in accordance with a change in the drying target for the electrode precursor, a change in outside humidity, a change in outside temperature, and the like.

The electrode manufacturing apparatus and the electrode manufacturing method according to still another embodiment of the present specification may derive and maintain optimal humidity for situations of the individual drying lines when the plurality of drying lines is controlled.

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 view illustrating an electrode manufacturing apparatus according to an embodiment of the present specification. The electrode manufacturing apparatus <NUM> includes a supply part <NUM>, a drying part <NUM>, a discharge part <NUM>, a monitoring part <NUM>, and a control part <NUM>. The electrode manufacturing apparatus <NUM> including the above-mentioned components may collect monitoring information obtained by the monitoring part <NUM> and humidity information measured by a sensor and control whether to open or close an air discharge part and a degree of humidification made by the humidifying part.

<FIG> is a view illustrating an electrode manufacturing apparatus in the related art. The electrode manufacturing apparatus may receive an electrode precursor <NUM>, which is made by applying electrode slurry onto a substrate, from the supply part <NUM> and dry the electrode precursor <NUM> by circulating high-temperature vapor. However, during a process of removing a solvent from the applied electrode slurry, a crack is formed in a surface of the dried electrode because of thermal properties of an electrode solvent and an active material, the amount of heat applied by oven specifications, a drying time according to a coating speed, and an influence of humidity in an oven.

To this end, the electrode manufacturing apparatus may select humidity that is determined to be theoretically or experientially appropriate, and the electrode manufacturing apparatus may maintain humidity in a drying furnace while sensing the humidity. However, because the predetermined humidity may be changed under the circumstances by a change in the drying target for the electrode precursor, a change in outside humidity, a change in outside temperature, and the like, the humidity, which is appropriate to a previous process, may not be suitable for the current process.

In addition, it is difficult to calculate and adjust humidity to be suitable for conditions that often change, and efficiency in calculating and applying the humidity is low.

The electrode manufacturing apparatus and the electrode manufacturing method according to the embodiment of the present specification may control optimal humidity in the drying part by a system on the basis of information obtained by monitoring the dried electrode.

An electrode manufacturing apparatus and an electrode manufacturing method according to another embodiment of the present specification may derive and maintain optimal humidity for the drying target electrode precursor in accordance with a change in drying target electrode precursor, a change in outside humidity, a change in outside temperature, and the like.

The supply part <NUM> supplies the electrode precursor <NUM> made by applying the electrode slurry onto the substrate. The way to supply the electrode precursor <NUM> is not particularly limited as long as the supply part <NUM> may supply the electrode precursor <NUM>. The electrode precursor <NUM> may be supplied as the electrode precursor <NUM> is unwound from a roll around which the electrode precursor <NUM> is wound. Alternatively, the substrate is unwound from a roll around which the substrate is wound, and a coating part (not illustrated) applies the electrode slurry onto at least one surface of the substrate, such that the coated electrode precursor <NUM> may be continuously supplied by a conveyance roll.

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

The electrode slurry, which is to be applied by the coater, 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 selected from electrode active materials used in the technical field.

The binder is not particularly limited as long as the binder may coagulate the electrode active material. The binder may be selected from binders used in the technical field.

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> is configured to dry the electrode slurry to manufacture an electrode <NUM>. The drying part <NUM> may include a heat source and dry the electrode slurry by applying heat. The heat source may include a hot-air blower or a near-infrared heater such as an NIR heater using a filament heating wire, a mid-infrared heater such as an MIR heater using a carbon heating wire, and the like. In this case, the drying temperature may be adjusted in accordance with the electrode slurry and selected within a range of about <NUM> to <NUM>. The drying part <NUM> may be divided and controlled in accordance with the position of the electrode precursor in the drying part <NUM>. The drying part may be divided into a preheating section that is an initial section to which the electrode precursor is supplied, a fixed rate section in which a large amount of evaporation is performed, a lapse rate section provided to perform final drying, and a late cooling section positioned before the electrode precursor is discharged to the outside of the drying part <NUM>. Specifically, in accordance with the position in the drying part <NUM>, the drying temperature is controlled to about <NUM> to <NUM> in the preheating section, about <NUM> to <NUM> in the fixed rate section, about <NUM> to <NUM> in the lapse rate section, and <NUM> to <NUM> in the cooling section.

In this case, high-temperature vapor may be supplied into the drying part <NUM> to adjust the humidity in a drying device. The electrode manufacturing apparatus may control an atmosphere in the drying part <NUM> to a predetermined temperature and humidity by supplying high-temperature vapor into the drying part <NUM>, supply the electrode precursor in the drying part <NUM>, dry the electrode precursor by using the heat source, and discharge the electrode, which is the dried electrode precursor, to the outside of the drying part <NUM>.

A temperature of the high-temperature vapor is not particularly limited as long as the temperature of the high-temperature vapor may maintain target absolute humidity without producing condensate water.

The absolute humidity of the high-temperature vapor may control the appropriate absolute humidity suitable for the electrode slurry. Specifically, the absolute humidity of the high-temperature vapor may be <NUM>/m<NUM> or more, and more specifically, <NUM>/m<NUM> or more and <NUM>/m<NUM> or less. Because condensate water may form on the drying part <NUM> when the absolute humidity becomes too high, the absolute humidity may be controlled in consideration of this situation.

The absolute humidity of the high-temperature vapor may be selected and controlled for each section in accordance with the drying target of the electrode slurry. Specifically, the section may be divided into a low-humidity section of <NUM>/m<NUM> or more and <NUM>/m<NUM> or less, a middle-humidity section of <NUM>/m<NUM> or more and <NUM>/m<NUM> or less, a high-humidity section of <NUM>/m<NUM> or more and <NUM>/m<NUM> or less, and an ultra-high-humidity section of <NUM>/m<NUM> or more and <NUM>/m<NUM> or less, and the humidity may be controlled to the absolute humidity in the corresponding range. The drying part <NUM> includes an air supply part <NUM>, an air introducing part <NUM>, a flow path <NUM>, a sensor <NUM>, an air discharge part <NUM>, and a humidifying part <NUM>.

A region is a space in which the electrode precursor <NUM> is provided from the supply part <NUM> to be dried by the drying part <NUM>, where the conditions for drying the electrode precursor <NUM> are adjusted, and the adjusted conditions are maintained. The region may be a drying furnace in which only minimum openings for supplying and discharging are included, i.e., supply and discharge openings are exposed to the outside in case that the electrode precursor <NUM> is continuously or intermittently supplied to the drying part <NUM> through a roll-to-roll process and the completely dried electrode <NUM> is discharged.

In addition to the supply and discharge openings, the drying part <NUM> may further include openings for supplying and introducing air. This opening is not an opening exposed directly to the outside. An opening may be provided to introduce high-temperature vapor used in the region to be dried, adjust the introduced air to a state of being reusable, and supply and circulate the air.

The air supply part <NUM> supplies the high-temperature vapor onto the electrode precursor <NUM>. The air supply part <NUM> may mean a region in which the high-temperature vapor is supplied onto the electrode precursor <NUM>. Specifically, the air supply part <NUM> may mean a hole through which the high-temperature vapor is supplied onto the electrode precursor <NUM>. In this case, a supply of air made by the air supply part <NUM> may be naturally generated by the circulation of air. However, particularly, a supply of air may be made by forcibly generating a flow of air by using a fan.

The air introducing part <NUM> introduces the supplied high-temperature vapor. The air introducing part <NUM> may mean a region in which the high-temperature vapor supplied onto the electrode precursor <NUM> is introduced. Specifically, the air introducing part <NUM> may mean a hole through which the high-temperature vapor supplied onto the electrode precursor <NUM> is introduced. In this case, the introduction of air made by the air introducing part <NUM> may be naturally generated by the circulation of air. However, particularly, the introduction of air may be made by forcibly generating a flow of air by using a fan.

The flow path <NUM> is connected from the air introducing part <NUM> to the air supply part <NUM> and defines a route through which the high-temperature vapor introduced into the air introducing part <NUM> circulates to be supplied back to the air supply part <NUM>. The shape of the flow path <NUM> is not particularly limited as long as the high-temperature vapor introduced into the air introducing part <NUM> may be supplied back to the air supply part <NUM>. Particularly, a cross-section of the flow path <NUM> may be a circular shape.

The sensor <NUM> measures humidity of the introduced high-temperature vapor. Specifically, the sensor <NUM> measures absolute humidity of the introduced high-temperature vapor. The absolute humidity is a measure for indicating the amount of moisture vapor contained in the high-temperature vapor and refers to mass of moisture vapor per unit volume. The absolute humidity is not affected by a temperature.

The sensor <NUM> is not limited to a particular measurement device as long as the sensor <NUM> may measure the humidity of the introduced high-temperature vapor. One end of the sensor <NUM> is at least exposed to the inside of a flow path of the air introducing part <NUM> so that the sensor <NUM> may measure the humidity of the introduced high-temperature vapor. Information on the humidity of the introduced high-temperature vapor, which is measured as described above, is transmitted, at a predetermined interval or in real time, to the control part <NUM> to be described below.

The air discharge part <NUM> is opened or closed to discharge, to the outside, a part of the high-temperature vapor that circulates from the air introducing part <NUM> toward the air supply part <NUM> along the flow path <NUM>. Whether to open or close the air discharge part <NUM> is determined by the control part <NUM> to be described below. The air discharge part <NUM> is opened to discharge foreign substances and evaporated solvent in the oven, such that a part of the high-temperature vapor circulating toward the air supply part <NUM> along the flow path <NUM> is discharged to the outside. In this case, the vapor, which is supplied to maintain the humidity in the oven, is also discharged. Therefore, a loss of vapor is adjusted by adjusting the amount of vapor to be discharged. The crack, which has been monitored by the monitoring part, is eliminated by adjusting the humidity. In case that the humidity is continuously increased without being maintained because of a delay of time occurring when the humidification made by the humidifying part <NUM> affects the overall humidity of the vapor in the oven even though the current humidity needs to be maintained, it is possible to stabilize the humidity by increasing the discharge amount by the air discharge part <NUM>. When the humidity increases and exceeds an appropriate humidity condition, the drying of the slurry is hindered, and a preferred drying condition cannot be achieved. Therefore, the humidity condition in which the crack is eliminated is maintained by increasing the discharge amount of air.

The humidifying part <NUM> humidifies the high-temperature vapor that circulates from the air introducing part <NUM> toward the air supply part <NUM> along the flow path <NUM>. The humidifying part <NUM> is not particularly limited to a humidification device and an installed position as long as the humidifying part <NUM> may humidify, as necessary, the high-temperature vapor that circulates from the air introducing part <NUM> toward the air supply part <NUM> along the flow path <NUM>. An end of the humidifying part <NUM> capable of supplying moisture is exposed to the inside of the flow path <NUM> so that the humidifying part <NUM> may humidify the high-temperature vapor that circulates from the air introducing part <NUM> toward the air supply part <NUM> along the flow path <NUM>. Whether to perform the humidification by the humidifying part <NUM> and a degree of humidification are controlled by the control part to be described below.

A drying temperature and time of the drying part <NUM> are not particularly limited and may be adjusted in accordance with properties of the electrode slurry that is the drying target.

The discharge part <NUM> may mean a region in which the manufactured electrode is discharged. The manufactured electrode may be moved by tension applied by a recovery roll that winds and stores the manufactured electrode <NUM>.

The monitoring part <NUM> monitors the electrode <NUM> discharged by the discharge part. The monitoring part <NUM> is positioned between the discharge part <NUM> and the recovery roll (not illustrated) and monitors the electrode <NUM> discharged by the discharge part. The monitoring part <NUM> may include a vision sensing part including a camera <NUM> configured to detect a crack in the discharged electrode <NUM>. Specifically, the monitoring part <NUM> may have the camera <NUM> directed toward a surface of the electrode on which the dried electrode precursor <NUM> is provided. The monitoring part <NUM> may include the vision sensing part including an analysis part (not illustrated) configured to analyze information collected by the camera <NUM>. Monitoring information of the monitoring part, which is analyzed as described above, is transmitted, at a predetermined interval or in real time, to the control part <NUM> to be described below.

The control part <NUM> collects the monitoring information obtained by the monitoring part <NUM> and the information on the humidity measured by the sensor and controls the humidity of the high-temperature vapor supplied into the drying part <NUM>. Specifically, the control part <NUM> controls whether to open or close the air discharge part <NUM> and the degree of humidification by the humidifying part <NUM>.

The control part <NUM> may increase the degree of humidification by the humidifying part <NUM> in order to increase the humidity of the high-temperature vapor. In this case, the humidity may vary depending on the amount of humidification by the humidifying part <NUM> and the amount of solvent in the electrode determined by the electrode design. Therefore, it is important to use the humidifying part <NUM> having a sufficient capacity while adjusting the amount of circulating high-temperature vapor.

The control part <NUM> may close the air discharge part <NUM> and decrease the amount of vapor to be discharged to the outside in order to increase the humidity of the high-temperature vapor.

The control part <NUM> may decrease a degree of humidification by the humidifying part <NUM> or stop the humidification in order to decrease the humidity of the high-temperature vapor.

In addition, to decrease the humidity of the high-temperature vapor, the control part <NUM> may discharge, to the outside, a part of the high-temperature vapor that circulates from the air introducing part <NUM> toward the air supply part <NUM> along the flow path <NUM>.

<FIG> is a view illustrating a series of processes performed when the monitoring part <NUM> of the embodiment of the present specification detects a crack in the completely dried electrode <NUM>.

When the monitoring part <NUM> detects a crack in the discharged electrode, the control part <NUM> increases the humidity, which is measured by the sensor <NUM> when the crack is formed in the discharged electrode, until the crack is not detected in the electrode. When the monitoring part <NUM> detects no crack in the discharged electrode, the control part <NUM> determines the humidity, which is measured by the sensor <NUM> when no crack is detected in the discharged electrode, and the control part <NUM> performs control to maintain the determined humidity of the high-temperature vapor in the drying part <NUM>.

When the monitoring part <NUM> detects a crack in the discharged electrode, the control part <NUM> increases the humidity, which is measured by the sensor <NUM> when the crack is formed in the discharged electrode, until no crack is detected in the electrode. A predetermined time is required to stabilize the humidity of the overall high-temperature vapor in the drying furnace by the humidification even though the humidification by the humidifying part <NUM> is increased to increase the humidity of the high-temperature vapor.

The humidifying part <NUM>, which receives an instruction to increase the degree of humidification from the control part <NUM>, increases the humidification, and the increased degree of humidification is reflected, such that a difference between the previous humidity and the humidity to be increased may be <NUM>% or more and <NUM>% or less. A predetermined time is required until the atmosphere in the drying part <NUM> is stabilized by the increased humidity and the electrode precursor dried in the atmosphere with the increased humidity is discharged. In this case, the predetermined time may be about <NUM> minutes experientially and increased or decreased depending on the size of the drying furnace. When a crack is detected in the dried electrode even under a changed condition, the control part instructs the humidifying part <NUM> to increase the degree of humidification once more. This process is repeatedly performed until no crack is detected in the electrode dried and discharged under the changed condition.

When no crack is detected in the electrode dried and discharged under the changed condition, the control part <NUM> instructs the humidifying part <NUM> to finally increase the humidity, and the increased target humidity or the increased humidity is stabilized. The control part determines the humidity of the introduced high-temperature vapor measured by the sensor <NUM> as the humidity at which no crack is detected in the discharged electrode. The determined humidity of the high-temperature vapor in the drying part <NUM> is controlled to be maintained until no further crack is formed in the electrode during a subsequent process.

<FIG> is a view illustrating an electrode manufacturing apparatus having two drying lines in the related art. The air discharged from the two drying lines to the entire circulation discharge air <NUM> may be mixed, the mixed entirely discharged air may be circulated, and a part of the entire circulating air may be discharged to the outside by the discharge part <NUM>. The entirely circulating air, which is not discharged to the outside by the discharge part <NUM>, and the air introduced from the outside are mixed by an air supply fan <NUM> and become the entire circulation supply air <NUM>. In addition, individual circulation discharge air <NUM> may be discharged from the individual drying lines. In this case, the individual circulation discharge air <NUM> and the entire circulation supply air <NUM> are mixed and become individual mixing supply air <NUM> by a circulation fan <NUM>, such that the high-temperature vapor circulates in the individual drying lines.

However, in the related art, the cracks occurring in the individual drying lines cannot be individually controlled.

<FIG> is a view illustrating an electrode manufacturing apparatus having two drying lines according to another embodiment of the present specification. Humidifying parts <NUM>' and <NUM>" and sensors <NUM>' and <NUM>" are respectively provided in the individual drying lines, and the control part <NUM>, which collects information from the individual drying lines, individually controls the humidity of the high-temperature vapor in the individual drying lines.

Claim 1:
An electrode manufacturing (<NUM>) apparatus comprising:
a supply part (<NUM>) configured to supply an electrode precursor (<NUM>); the electrode precursor (<NUM>) including an electrode slurry disposed on a substrate;
a drying part (<NUM>) configured to dry the electrode slurry so as to manufacture an electrode (<NUM>), wherein the drying part (<NUM>) includes:
an air supply part (<NUM>) configured to supply a high-temperature vapor to the electrode precursor (<NUM>),
an air introducing part (<NUM>) configured to introduce the high-temperature vapor to a flow path (<NUM>), wherein the flow path (<NUM>) is configured to communicate the air introducing part (<NUM>) with the air supply part (<NUM>),
a sensor (<NUM>) configured to measure a humidity of the high-temperature vapor in the flow path (<NUM>),
an air discharge part (<NUM>) configured to be opened or closed, so as to discharge a part of the high-temperature vapor that circulates from the air introducing part (<NUM>) toward the air supply part (<NUM>) along the flow path (<NUM>), and
a humidifying part (<NUM>) configured to humidify the high-temperature vapor that circulates from the air introducing part (<NUM>) toward the air supply part (<NUM>) along the flow path (<NUM>);
a discharge part (<NUM>) configured to discharge the electrode (<NUM>);
a monitoring part (<NUM>) configured to monitor the electrode (<NUM>) discharged by the discharge part (<NUM>); and
a control part (<NUM>) configured to collect monitoring information obtained by the monitoring part (<NUM>) and humidity information measured by the sensor (<NUM>); wherein the control part (<NUM>) is configured to control whether to open or close the air discharge part (<NUM>) and to control a degree of humidification by the humidifying part (<NUM>)
wherein the control part (<NUM>) is configured to increase the humidity of the high temperature vapor when the monitoring part (<NUM>) detects the crack in the electrode (<NUM>) until no crack is detected in the electrode (<NUM>), and
wherein the monitoring part (<NUM>) is configured to maintain a determined humidity of the high-temperature vapor in the drying part (<NUM>) when the monitoring part (<NUM>) detects no crack in the electrode (<NUM>), wherein the control part (<NUM>) is configured to determine the humidity when no crack is detected in the electrode (<NUM>).