Patent Description:
The present specification relates to an electrode slurry control device.

Recently, prices of energy sources have been raised 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 substrate.

The slurry is supplied from an ink storage to a coating device and applied onto the substrate. The slurry may be continuously supplied in case that continuous coating is performed. The slurry may be intermittently supplied in case that the substrate is replaced or a pattern having a coated portion and a non-coated portion needs to be formed on the substrate.

In this case, there is a need for a means capable of controlling processes of supplying the slurry and stopping the supply of slurry in order to temporarily and continuously supply the slurry or stop the supply of slurry as necessary. The processes of supplying the slurry and stopping the supply of slurry need to be precisely controlled in case that a more precise pattern is required. <CIT>, <CIT>, <CIT> and <CIT> relate to the field of coating device. [Detailed Description of the Invention].

The present specification is intended to provide an electrode slurry control device.

An embodiment of the present specification provides an electrode slurry control device including: a main body having a receiving port configured to receive electrode slurry from an outside storage; a coater configured to discharge electrode slurry onto a substrate; a supply tube configured to supply the electrode slurry in the main body to the coater and connected to the main body through a first connection tube having a first opening/closing member; a first circulation tube configured to move a part of the electrode slurry introduced into the main body to the storage, the first circulation tube being connected to the main body through a second connection tube having a second opening/closing member; and a second circulation tube configured to move a part of the electrode slurry in the main body to the storage and connected to the main body through a third connection tube having a third opening/closing member, in which an average diameter of an inner peripheral surface of the second connection tube is smaller than an average diameter of an inner peripheral surface of the first circulation tube, and in which an average diameter of an inner peripheral surface of the third connection tube is larger than an average diameter of an inner peripheral surface of the second connection tube.

In another embodiment of the present specification, when the first opening/closing member closes the first connection tube, the second opening/closing member may open the second connection tube, the third opening/closing member may open the third connection tube, or the second opening/closing member and the third opening/closing member may respectively open the second connection tube and the third connection tube, and when the first opening/closing member opens the first connection tube, the second opening/closing member and the third opening/closing member may respectively close the second connection tube and the third connection tube.

In another embodiment of the present specification, an average diameter of an inner peripheral surface of the first connection tube may be smaller than an average diameter of an inner peripheral surface of the supply tube, the first opening/closing member may have a conical shape, a diameter of a conical lateral surface facing the first connection tube may gradually decrease toward the first connection tube, and a cone angle of the conical lateral surface may be <NUM> to <NUM> degrees.

In another embodiment of the present specification, the second opening/closing member may have a conical shape, a diameter of a conical lateral surface facing the second connection tube may gradually decrease toward the second connection tube, and a cone angle of the conical lateral surface may be <NUM> to <NUM> degrees.

In another embodiment of the present specification, the third opening/closing member may be a ball valve having a through-hole, and the average diameter of the inner peripheral surface of the third connection tube may be an average diameter of the through-hole.

In another embodiment of the present specification, the electrode slurry control device may further include a confluent tube connected to the first circulation tube and the second circulation tube so that the electrode slurry moving to the main body through the first circulation tube and the electrode slurry moving to the main body through the second circulation tube are merged.

The electrode slurry control device according to the present specification may reduce shear stress of supplied electrode slurry.

The electrode slurry control device according to the present specification may uniformly control the amount of loading the supplied electrode slurry.

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 perspective view of an electrode slurry control device <NUM> according to an embodiment of the present specification, and <FIG> is a cross-sectional view of the electrode slurry control device <NUM> according to the embodiment of the present specification.

The electrode slurry control device <NUM> includes a main body <NUM>, a supply tube <NUM>, a first circulation tube <NUM>, and a second circulation tube <NUM>.

The main body <NUM> has a receiving port <NUM> formed at an end thereof, and the receiving port <NUM> is provided to receive electrode slurry from a storage (not illustrated) that stores the electrode slurry. In addition, a first connection tube <NUM> connected to a first opening <NUM> of the main body <NUM> is opened or closed by a first opening/closing member <NUM>. When the first connection tube <NUM> is opened, the electrode slurry in the main body <NUM> is supplied to a coater through the supply tube <NUM>, and the coater discharges the electrode slurry onto a substrate. A second connection tube <NUM> connected to a second opening <NUM> of the main body <NUM> is opened or closed by a second opening/closing member <NUM>. When the second connection tube <NUM> is opened, the electrode slurry in the main body <NUM> is moved to the storage through the first circulation tube <NUM>. A third connection tube <NUM> connected to a third opening <NUM> of the main body <NUM> is opened or closed by a third opening/closing member <NUM>. When the third connection tube <NUM> is opened, the electrode slurry in the main body <NUM> is moved to the storage through the second circulation tube <NUM>.

The supply tube <NUM> is coupled to the coater (not illustrated) configured to coat the substrate. The first circulation tube <NUM> is connected to the second opening <NUM> of the main body <NUM> and the storage and configured to circulate the electrode slurry to the outside storage.

In this case, the main body <NUM>, the supply tube <NUM>, and the first circulation tube <NUM> may be provided in the form of a cylindrical tube, and an average diameter and shape of each of the main body <NUM>, the supply tube <NUM>, and the first circulation tube <NUM> may be freely changed because the average diameter and shape may be freely designed by a designer, as necessary.

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. In the case of the positive electrode, the electrode active material may be LCO (LiCoO<NUM>), NCM (Li(NiCoMn)O<NUM>), NCA (Li(NiCoAl)O<NUM>), LMO (LiMn<NUM>O), LFP (LiFePO<NUM>), or the like. The electrode active material may be carbon (graphite) or the like in the case of the negative electrode.

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 supply tube <NUM> is connected to the main body <NUM> through the first connection tube <NUM>. Therefore, the first connection tube <NUM> is positioned between the supply tube <NUM> and the main body <NUM>. An average diameter r1 of an inner peripheral surface of the first connection tube <NUM> is smaller than an average diameter R1 of an inner peripheral surface of the supply tube <NUM>.

Meanwhile, an average diameter of an outer peripheral surface of the first connection tube <NUM> may be equal to an average diameter of an outer peripheral surface of the supply tube <NUM> to implement convenience and stability in coupling the first connection tube <NUM> and the supply tube <NUM>.

In this case, the first connection tube <NUM> may be made of a metallic material having predetermined rigidity. Any material may be used as long as the material may withstand a pressure applied by the supply of the electrode slurry.

The first circulation tube <NUM> is connected to the main body <NUM> through the second connection tube <NUM>. Therefore, the second connection tube <NUM> is positioned between the first circulation tube <NUM> and the main body <NUM>. An average diameter r2 of an inner peripheral surface of the second connection tube <NUM> is smaller than an average diameter R2 of an inner peripheral surface of the first circulation tube <NUM>.

Meanwhile, an average diameter of an outer peripheral surface of the first circulation tube <NUM> may be equal to an average diameter of an outer peripheral surface of the first circulation tube <NUM> to implement convenience and stability in coupling the second connection tube <NUM> and the first circulation tube <NUM>.

In this case, the second connection tube <NUM> may be made of a metallic material having predetermined rigidity. Any material may be used as long as the material may withstand a pressure applied by the supply of the electrode slurry.

The second circulation tube <NUM> is connected to the main body <NUM> through the third connection tube <NUM>. Therefore, the third connection tube <NUM> is positioned between the second circulation tube <NUM> and the main body <NUM>.

The second circulation tube <NUM> has the third opening/closing member <NUM>. An average diameter of an inner peripheral surface of the third connection tube <NUM> is an average diameter of a hole opened by the third opening/closing member <NUM>. For example, the third opening/closing member <NUM> may be a ball valve having a through-hole. An average diameter r3 of an inner peripheral surface of the third connection tube <NUM> may be an average diameter r3 of the through-hole. The average diameter r3 of the inner peripheral surface of the third connection tube <NUM> is equal to or smaller than an average diameter R3 of an inner peripheral surface of the second circulation tube <NUM>.

Meanwhile, an average diameter of an outer peripheral surface of the third connection tube <NUM> may be equal to an average diameter of an outer peripheral surface of the second circulation tube <NUM> to implement convenience and stability in coupling the third connection tube <NUM> and the second circulation tube <NUM>. To implement convenience and stability in coupling the third connection tube <NUM> and the second circulation tube <NUM>, an average diameter of an end of the third connection tube <NUM> coupled to the second circulation tube <NUM> may be equal to the average diameter of the outer peripheral surface of the second circulation tube <NUM>, and an average diameter of an outer peripheral surface of a portion where the third opening/closing member <NUM> is provided may be larger than the average diameter of the outer peripheral surface of the second circulation tube <NUM>.

In this case, the third connection tube <NUM> may be made of a metallic material having predetermined rigidity. Any material may be used as long as the material may withstand a pressure applied by the supply of the electrode slurry.

The first opening/closing member <NUM> is provided in the supply tube <NUM> and configured to open or close the first connection tube <NUM>. The second opening/closing member <NUM> is provided in the first circulation tube <NUM> and configured to open or close the second connection tube <NUM>.

The second opening/closing member <NUM> may be identical in shape to the first opening/closing member <NUM>, and the second opening/closing member <NUM> may be different in size and average diameter from the first opening/closing member <NUM>. However, because the second opening/closing member <NUM> may open or close the second connection tube <NUM> on the same principle as the first opening/closing member <NUM> that opens or closes the first connection tube <NUM>, a repeated description thereof will be omitted.

The first opening/closing member <NUM> has a conical lateral surface <NUM> that faces the first connection tube <NUM>. When a cone, which faces the first connection tube <NUM>, and particularly, is defined by the conical lateral surface <NUM>, is referred to as a first cone, a second conical lateral surface <NUM> may be formed and positioned to correspond to a side opposite to the first cone.

The first opening/closing member <NUM> may be a cone valve having a conical shape so that a diameter of the conical lateral surface <NUM> facing the first connection tube <NUM> gradually decreases outward.

In this case, the conical lateral surface <NUM> and the second conical lateral surface <NUM> each have a conical shape having a diameter that gradually decreases outward. In this case, the conical lateral surface means a curved surface defined by connecting a vertex and a circle of a bottom of a conical shape.

Therefore, the first opening/closing member <NUM> has a single conical shape or a shape defined by bonding bottoms of two identical cones. In case that the first opening/closing member <NUM> has a shape defined by bonding bottoms of two identical cones, a conical shape of the conical lateral surface <NUM> and a conical shape of the second conical lateral surface <NUM> define a symmetric structure.

In this case, the second conical lateral surface <NUM> of the first opening/closing member <NUM> may be formed sharply in a conical shape, or a vertex of the second conical lateral surface <NUM> may be rounded.

A cone angle of the first opening/closing member <NUM> may be <NUM> to <NUM> degrees. Specifically, the cone angle of the first opening/closing member <NUM> may be <NUM> to <NUM> degrees, <NUM> to <NUM> degrees, or <NUM> to <NUM> degrees. Particularly, the cone angle of the first opening/closing member <NUM> may be <NUM> degrees.

<FIG> are views illustrating comparison of flow velocity, shear stress, and pressure of the electrode slurry between when a cone valve in the related art having a cone angle of <NUM> degrees is opened or closed and when a cone valve having a cone angle of <NUM> degrees is opened or closed.

It is possible to implement an effect of reducing frictional resistance against the electrode slurry when the first opening/closing member <NUM> and the second opening/closing member <NUM> repeatedly reciprocate.

In addition, the friction between the first opening/closing member <NUM> and the electrode slurry may be reduced, such that the pressure of the electrode slurry applied to the first opening/closing member <NUM> when the first opening/closing member <NUM> moves may be reduced, which makes it possible to prevent malfunction, minimize the amount of electrode slurry pushed upward to a location above the second conical lateral surface <NUM>, and prevent the occurrence of a portion where a large amount of coating is locally performed during an initial coating process.

Meanwhile, the first opening/closing member <NUM> may be formed by bonding bottoms of two identical cones. Alternatively, the first opening/closing member <NUM> may be initially manufactured in a shape identical to the shape defined by bonding the bottoms of the two identical cones without bonding the bottoms of the two identical cones.

However, the first opening/closing member <NUM> may be formed in a shape defined by coupling two cones selectively having different average diameters in accordance with the type, viscosity, and other properties of the electrode slurry.

In addition, the material of the first opening/closing member <NUM> may have predetermined rigidity without having permeability so as to perfectly block the electrode slurry introduced into the supply tube <NUM> through the first connection tube <NUM>. Specifically, the material of the first opening/closing member <NUM> may be, but not limited to, a metallic material.

Meanwhile, the first opening/closing member <NUM> further includes a first connection member <NUM> connected to a driving part (not illustrated). The second opening/closing member <NUM> further includes a second connection member <NUM> connected to the driving part (not illustrated).

The first and second connection members <NUM> and <NUM> may be provided in the form of a bar. When power is transmitted to the first and second connection members <NUM> and <NUM> by the driving part, the first and second opening/closing members <NUM> and <NUM> may move.

In this case, the first and second connection members <NUM> and <NUM> may each have rigidity to a degree to which the first and second connection members <NUM> and <NUM> may withstand the pressure applied in the main body <NUM> by the electrode slurry. Specifically, the first and second connection members <NUM> and <NUM> may each be made of a metallic material.

In addition, the first and second connection members <NUM> and <NUM> may each have a thickness much smaller than the average diameter of the inner peripheral surface of each of the first and second connection tubes <NUM> and <NUM>. This is to prevent the first and second connection members <NUM> and <NUM> from occupying large volumes in the first and second connection tubes <NUM> and <NUM> and to minimize the extent to which the movements of the first and second connection members <NUM> and <NUM> affect the movement of the electrode slurry.

<FIG> is a view illustrating an operating state in which the supply tube <NUM> is opened and the first and second circulation tubes <NUM> and <NUM> are closed in the electrode slurry control device. <FIG> is a view illustrating an operating state in which the supply tube <NUM> and the first circulation tube <NUM> are closed and the second circulation tube <NUM> is opened in the electrode slurry control device. <FIG> is a view illustrating an operating state in which the supply tube <NUM> and the second circulation tube <NUM> are closed and the first circulation tube <NUM> is opened in the electrode slurry control device. <FIG> is a view illustrating an operating state in which the supply tube <NUM> is closed and the first and second circulation tubes <NUM> and <NUM> are opened in the electrode slurry control device.

As illustrated in <FIG> and <FIG>, the first connection member <NUM> connected to the driving part (not illustrated) allows the first opening/closing member <NUM> to open or close the first connection tube <NUM>, and the second connection member <NUM> allows the second opening/closing member <NUM> to open or close the second connection tube <NUM>.

The third opening/closing member <NUM> may be a ball valve having a through-hole <NUM>. A ball <NUM> having the through-hole <NUM> may be provided in the third connection tube <NUM>, and the ball <NUM> may be rotated by a valve <NUM> coupled to an outer surface of the ball <NUM>. As illustrated in <FIG> and <FIG>, the through-hole <NUM> is opened when the through-hole <NUM> is positioned to be connected to the second circulation tube <NUM> by the rotation of the ball <NUM>. As illustrated in <FIG> and <FIG>, the through-hole <NUM> is closed when the through-hole <NUM> is not connected to the second circulation tube <NUM> by the rotation of the ball.

In this case, when the first opening/closing member <NUM> closes the first connection tube <NUM>, at least any one of the third connection tube <NUM> and the second connection tube <NUM> is opened by the third opening/closing member <NUM> and/or the second opening/closing member <NUM>. When the first opening/closing member <NUM> opens the first connection tube <NUM>, the second opening/closing member <NUM> closes the second connection tube <NUM>, and the third opening/closing member <NUM> closes the third connection tube <NUM>.

Specifically, referring to <FIG>, <FIG>, and <FIG>, the conical lateral surface <NUM> of the first opening/closing member <NUM> is inserted into the first connection tube <NUM> while being in close contact with the first connection tube <NUM>. The first connection tube <NUM> is closed as the conical lateral surface <NUM> of the first opening/closing member <NUM> is inserted into the first connection tube <NUM> while being in close contact with the first connection tube <NUM>. A position of the first opening/closing member <NUM> when the movement of the electrode slurry to the supply tube <NUM> is blocked may be defined as a "first position".

Referring to <FIG>, the entire conical lateral surface <NUM> of the first opening/closing member <NUM> is withdrawn from the first connection tube <NUM>. A position of the first opening/closing member <NUM> when the first connection tube <NUM> is opened and the electrode slurry may move to the supply tube <NUM> may be defined as a "second position".

Meanwhile, a position of the second opening/closing member <NUM> in a state in which the second opening/closing member <NUM> is inserted into the second connection tube <NUM> while being in close contact with the second connection tube <NUM> and the second connection tube <NUM> is closed as illustrated in <FIG> and <FIG> may be defined as a "third position". A position of the second opening/closing member <NUM> in a state in which the entire second opening/closing member <NUM> is withdrawn from the second connection tube <NUM> and the second connection tube <NUM> is opened as illustrated in <FIG> and <FIG> may be defined as a "fourth position".

That is, the first position of the first opening/closing member <NUM> may correspond to the third position of the second opening/closing member <NUM>, and the second position of the first opening/closing member <NUM> may correspond to the fourth position of the second opening/closing member <NUM>.

Meanwhile, a position of the third opening/closing member <NUM> in a state in which the third opening/closing member <NUM> is inserted into the third connection tube <NUM> while being in close contact with the third connection tube <NUM> and the third connection tube <NUM> is closed as illustrated in <FIG> and <FIG> may be defined as a "fifth position". A position of the third opening/closing member <NUM> in a state in which the third opening/closing member <NUM> is rotated and the third connection tube <NUM> is opened as illustrated in <FIG> and <FIG> may be defined as a "sixth position".

First, an operational principle will be described with reference to <FIG> and <FIG>. The first opening/closing member <NUM> moves toward the first connection tube <NUM>, and then the conical lateral surface <NUM> of the first opening/closing member <NUM> is inserted into the first connection tube <NUM> and thus positioned at the first position. The second opening/closing member <NUM> moves toward a side opposite to the second connection tube <NUM>, and then the conical lateral surface <NUM> of the second opening/closing member <NUM> is completely withdrawn from the second connection tube <NUM> and thus positioned at the fourth position. In this case, the third opening/closing member <NUM> may be positioned at the fifth position, i.e., the closed state illustrated in <FIG> or positioned at the sixth position, i.e., the opened state illustrated in <FIG>.

On the contrary, referring to <FIG>, the first opening/closing member <NUM> moves toward the side opposite to the first connection tube <NUM>, and then the conical lateral surface <NUM> of the first opening/closing member <NUM> is completely withdrawn from the first connection tube <NUM> and thus positioned at the second position. The second opening/closing member <NUM> moves toward the second connection tube <NUM>, and then the conical lateral surface <NUM> of the second opening/closing member <NUM> is inserted into the second connection tube <NUM> and thus positioned at the third position, and the third opening/closing member <NUM> is positioned at the fifth position, i.e., the closed state.

Therefore, when the first connection tube <NUM> is in a fully opened state (second position), the second and third connection tubes <NUM>, <NUM> are positioned in fully closed states (third and fifth positions). In this case, a coated portion is formed on the substrate. In addition, when the first connection tube <NUM> is in a fully closed state (first position), the second connection tube <NUM> is positioned in a fully opened state (fourth position), and the third connection tube <NUM> is selectively opened or closed. In this case, a non-coated portion may be formed on the substrate.

That is, the first and second opening/closing members <NUM> and <NUM> may reciprocate at high speed in opposite directions and intermittently form the coated portion and the non-coated portion on the substrate only under the control of the opening/closing member without complicatedly controlling a slurry supply pump.

The electrode slurry control device <NUM> has the first circulation tube <NUM> separately provided in addition to the supply tube <NUM>, such that the electrode slurry may continuously circulate through the main body <NUM> even at the time of forming the non-coated portion on the substrate, which makes it possible to reduce the pressure applied to the main body <NUM> even without stopping the operation of the slurry supply pump.

When the second connection tube <NUM> is in the fully opened state (fourth position), physical properties of the electrode slurry passing through the second connection tube <NUM> are changed, which may adversely affect electrode coating quality. This is because of the shape of the second opening/closing member <NUM> and the shape of the second connection tube <NUM> that apply high shear stress to the slurry.

The shear stress is an essential element to disperse the slurry in a mixing process that is a step performed prior to a coating process. However, the shear stress needs to be minimized after the slurry is completed through the mixing process. If an additional shearing force is inadvertently generated after the mixing process, the flowing two problems may occur.

First, the shear stress may adversely affect an interface of the slurry applied onto the substrate. When the shear stress is consistently applied to the slurry, a viscosity of the slurry (viscosity curve) is changed. In particular, a viscosity gradient of a viscosity curve (having an x-axis indicating viscosities and a y-axis indicating shear rates) affects a shape of the interface of the slurry applied onto the substrate. If a coating interface cannot be managed, an appropriate ratio between the positive electrode and the negative electrode in the completed lithium-ion battery is broken, which may cause a fire due to lithium precipitation.

Second, when the shear stress is applied by viscoelastic properties in the case of the negative electrode, there may occur a problem in that a filter (a foreign substance filter installed in a slurry movement tube) is clogged or coating quality deteriorates. (Viscoelasticity means an indicator indicating viscosity (viscous property) and elasticity (elastic property) of an object). When the shearing force is applied in the case of the negative electrode, a particle network is formed, which may cause a risk that solid properties are shown. For this reason, there occurs a problem in that the filter is clogged or coating quality deteriorates.

To solve the above-mentioned problems, an object of the present disclosure is to provide a method that additionally provides the second circulation tube <NUM> and allows the slurry to bypass the second opening/closing member <NUM> and the second connection tube <NUM> that apply high shear stress to the slurry. Further, an object of the present disclosure is to improve a shape of the first opening/closing member <NUM>, a shape of the first connection tube <NUM>, a shape of the second opening/closing member <NUM>, and a shape of the second connection tube <NUM> to minimize the shear stress.

To solve the problem, the state of the third connection tube <NUM> is changed to the fully opened state (sixth position) in case that the coating is stopped over a long period of time. Therefore, the slurry may bypass the second opening/closing member <NUM> and the second connection tube <NUM> and thus less receive shear stress, which makes it possible to prevent a change in physical properties.

In case that the coating is stopped over a long period of time, the third opening/closing member <NUM> may be opened, and the third connection tube <NUM> may be opened. However, during the intermittent coating (pattern coating), the slurry needs to be controlled by the first opening/closing member <NUM> and the second opening/closing member <NUM> that may be opened or closed at high speed, and the third connection tube <NUM> needs to be closed. Therefore, in case that the coating is instantaneously stopped during the intermittent coating, the slurry needs to inevitably pass through the second opening/closing member <NUM> and the second connection tube <NUM>. In case that the coating is performed, the slurry needs to inevitably pass through the first opening/closing member <NUM> and the first connection tube <NUM>. The present disclosure prevents a change in physical properties of the slurry by minimizing the shear stress applied to the slurry by setting the cone angle of the opening/closing member to <NUM> to <NUM> degrees.

A person skilled in the art may understand that the present invention may be carried out in other specific forms without changing the essential characteristics of the present invention. Therefore, it should be understood that the above-described embodiments are illustrative in all aspects and do not limit the present invention. The scope of the present invention is represented by the claims rather than the detailed description, and it should be interpreted that the meaning and scope of the claims and various embodiments derived from the equivalent concepts thereto fall within the scope of the present invention.

Hereinafter, the present specification will be described in more detail with reference to Examples. However, the following examples are intended to illustratively describe the present specification, and the scope of the present specification is not limited by the following examples.

A flow analysis was performed to evaluate the effect of the present disclosure that minimizes the shear stress applied to the slurry by setting the cone angle of the opening/closing member to <NUM> to <NUM> degrees. The opening/closing member in the related art having a cone angle of <NUM> degrees and the opening/closing member according to the present disclosure having a cone angle of <NUM> degrees are compared and analyzed. A specific flow analysis method is as follows. One of negative electrode slurry used for a cylindrical battery of LG energy solution was used as a working fluid. A viscosity curve of the slurry was obtained by being actually measured by a viscometer, and then was curve-fitted to a Carreau-Yasuda model, and inputted into a flow analysis program. Variables such as a density of the slurry, a flow rate of the slurry, a size of the valve, and a stroke of the valve (a degree to which the valve is opened) were selected so that an actual coating process is properly reflected. The analysis was performed in a steady state, and a turbulent flow model was used. The used analysis tool is STAR-CCM+ of Siemens. The results are shown in <FIG> and <FIG>.

<FIG> is a view illustrating a change in flow velocity in the connection tube in which the cone valve having a cone angle of <NUM> degrees is provided in a regular position, and <FIG> is a view illustrating a change in flow velocity in the connection tube in which the cone valve having a cone angle of <NUM> degrees is provided in a regular position.

<FIG> is a view illustrating a change in flow velocity in the connection tube in which the cone valve having the cone angle of <NUM> degrees is provided in a reverse position, and <FIG> is a view illustrating a change in flow velocity in the connection tube in which the cone valve having the cone angle of <NUM> degrees is provided in a reverse position.

According to the results of the flow analysis illustrated in <FIG> and <FIG>, it can be seen that the use of the opening/closing member having the cone angle of <NUM> degrees may reduce a maximum flow velocity of the slurry in comparison with the opening/closing member having the cone angle of <NUM> degrees illustrated in <FIG> and <FIG>. The shear stress applied to the fluid is (viscosity × shear strain rate). In general, when the other conditions remain the same, the shear strain rate decreases as the flow velocity decreases. Therefore, it can be seen that the maximum shear stress applied to the slurry is further decreased when the cone angle is <NUM> degrees than when the cone angle is <NUM> degrees.

Like Experimental Example <NUM>, a flow analysis was performed to evaluate the effect of the present disclosure that minimizes the shear stress applied to the slurry by setting the cone angle of the opening/closing member to <NUM> to <NUM> degrees. In this case, the shear stress was calculated by (slurry viscosity × slurry shear strain rate). A specific flow analysis method is identical to that in Experimental Example <NUM>. The results showing the distribution of the shear stress applied to the slurry are shown in <FIG> and <FIG>.

Specifically, <FIG> is a view illustrating a change in shear stress in the connection tube in which the cone valve having the cone angle of <NUM> degrees is provided in the regular position, and <FIG> is a view illustrating a change in shear stress in the connection tube in which the cone valve having the cone angle of <NUM> degrees is provided in the regular position. In addition, <FIG> is a view illustrating a change in shear stress in the connection tube in which the cone valve having the cone angle of <NUM> degrees is provided in the reverse position, and <FIG> is a view illustrating a change in shear stress in the connection tube in which the cone valve having the cone angle of <NUM> degrees is provided in the reverse position.

It can be seen, from the contour graphs in <FIG> and <FIG>, that the maximum shear stress applied to the slurry is further decreased when the cone angle is <NUM> degrees than when the cone angle is <NUM> degrees.

In the present experiment, a flow analysis was performed to analyze a pressure loss when the cone angle was set to <NUM> to <NUM> degrees. A specific flow analysis method is identical to that in Experimental Example <NUM>. The results showing the distribution of the static pressure applied to the slurry are shown in <FIG> and <FIG>.

Specifically, <FIG> is a view illustrating a change in pressure in the connection tube in which the cone valve having the cone angle of <NUM> degrees is provided in the regular position, and <FIG> is a view illustrating a change in pressure in the connection tube in which the cone valve having the cone angle of <NUM> degrees is provided in the regular position. In addition, <FIG> is a view illustrating a change in pressure in the connection tube in which the cone valve having the cone angle of <NUM> degrees is provided in the reverse position, and <FIG> is a view illustrating a change in pressure in the connection tube in which the cone valve having the cone angle of <NUM> degrees is provided in the reverse position.

It can be seen, from the contour graphs illustrated in <FIG> and <FIG>, that the pressure loss is further decreased when the cone angle is <NUM> degrees than when the cone angle is <NUM> degrees. According to Experimental Examples <NUM> to <NUM>, it can be ascertained that the use of the opening/closing member having the cone angle of <NUM> to <NUM> degrees may reduce a load of the slurry pump and make the smooth motion of the opening/closing member.

The flow analysis of the present experiment shows that a tube system in the related art, in which the second circulation tube <NUM> and the third opening/closing member <NUM> are not installed, affects the slurry. A valve having a cone angle of <NUM> degrees in the related art was used as the opening/closing member. The analysis region is a tube system in which the first opening/closing member <NUM> is closed and the second opening/closing member <NUM> is opened (coating interruption period). The flow analysis method on the remaining region, except for the analysis region, is identical to that in Experimental Example <NUM>. The results are shown in <FIG>, <FIG>, and <FIG>. <FIG>, <FIG>, and <FIG> illustrate a flow velocity distribution, a shear stress distribution, and a static pressure distribution, respectively.

The contour graph in <FIG> shows that a high flow velocity occurs in the vicinity of the second opening/closing member during the coating interruption period. Therefore, <FIG> illustrates that high shear stress occurs in the vicinity of the second opening/closing member. <FIG> illustrates that the second opening/closing member generates most of the pressure loss.

Therefore, it can be seen that the second circulation tube <NUM>, which allows the slurry to bypass the second opening/closing member <NUM>, is additionally required when the coating is stopped over a long period of time.

The flow analysis of the present experiment shows that the slurry control device having the second circulation tube <NUM> and the third opening/closing member <NUM> affects the slurry. Like Experimental Example <NUM>, the analysis region is a tube system in which the first opening/closing member <NUM> is closed and the second opening/closing member <NUM> is opened (coating interruption period). However, in the system, the second circulation tube <NUM> is added, and the third opening/closing member <NUM> is opened, such that the slurry may bypass the second opening/closing member <NUM>. The flow analysis method on the remaining region, except for the analysis region, is identical to that in Experimental Example <NUM>. The analysis results are shown in <FIG>, <FIG>, and <FIG>. <FIG>, <FIG>, and <FIG> illustrate a flow velocity distribution, a shear stress distribution, and a static pressure distribution, respectively.

<FIG> illustrates that most of the slurry flows through the second circulation tube <NUM> and bypasses the second opening/closing member <NUM>. Therefore, in comparison with <FIG>, <FIG> illustrates that the shear stress decreases in the vicinity of the second opening/closing member. In addition, in comparison with <FIG>, <FIG> illustrates that the pressure loss greatly decreases (<NUM> kPa → <NUM> kPa).

Claim 1:
An electrode slurry control device (<NUM>) comprising:
a main body (<NUM>) having a receiving port (<NUM>) configured to receive electrode slurry from an outside storage;
a coater configured to discharge the electrode slurry onto a substrate;
a supply tube (<NUM>) configured to supply the electrode slurry from the main body (<NUM>) to the coater, the supply tube (<NUM>) being connected to the main body (<NUM>) through a first connection tube (<NUM>) having a first opening/closing member (<NUM>);
a first circulation tube (<NUM>) configured to move a part of the electrode slurry from the main body (<NUM>) to the storage (<NUM>), the first circulation tube (<NUM>) being connected to the main body (<NUM>) by a second connection tube (<NUM>) having a second opening/closing member (<NUM>); and
a second circulation tube (<NUM>) configured to move a part of the electrode slurry from the main body (<NUM>) to the storage (<NUM>), the second circulation tube (<NUM>) being connected to the main body (<NUM>) by a third connection tube (<NUM>) having a third opening/closing member (<NUM>),
wherein an average diameter (r2) of an inner peripheral surface of the second connection tube (<NUM>) is smaller than an average diameter (R2) of an inner peripheral surface of the first circulation tube (<NUM>), and
wherein an average diameter (r3) of an inner peripheral surface of the third connection tube (<NUM>) is larger than an average diameter (r2) of an inner peripheral surface of the second connection tube (<NUM>).