One]This application claims the benefit of priority based on Korean Patent Application No. 10-2019-0143427 dated November 11, 2019, and all contents disclosed in the literature of the Korean patent application are incorporated as a part of this specification.
[2]The present invention relates to an electrode slurry coating apparatus and method comprising a pressure regulating member.
background
[3]
With the increase in technology development and demand for mobile devices, the demand for secondary batteries is also rapidly increasing. Among them, a lithium secondary battery is widely used as an energy source for various electronic products as well as various mobile devices in that it has high energy density and operating voltage and excellent preservation and lifespan characteristics.
[4]
In addition, the secondary battery has a structure in which an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive and negative electrodes are accommodated in a battery case while being impregnated with an electrolyte. The positive electrode and the negative electrode have, for example, a structure in which an electrode slurry including an active material is coated on a current collector formed of a metal foil such as aluminum or copper.
[5]
1 is a schematic diagram illustrating a process of discharging an electrode slurry on a current collector layer using a conventional electrode slurry coating apparatus. Referring to FIG. 1 , the electrode slurry coating apparatus has a structure in which an electrode slurry discharge channel 11 for discharging an electrode slurry 21 is formed through a slit formed at an interface between two dies. In addition, the slurry supply passage 12 is fluidly connected to the slurry discharge passage 11 , and the electrode slurry 21 is supplied therethrough. The current collector layer 30 formed of the metal foil passes through the front of the electrode slurry discharge passage 11 through a conveyor (not shown) driven by the rotating roller 40 . The discharged electrode slurry is discharged on the current collector layer 30 . The structure shown in FIG. 1 is a structure in which the holding part 22 and the uncoated part 23 are repeatedly formed on the current collector layer 30 . The holding part 22 is an area coated with the electrode slurry, and the uncoated area 23 is an area where the electrode slurry is not coated. The electrode slurry coating apparatus repeats discharging and stopping of the electrode slurry 21 . However, an excessive load is applied to the electrode slurry discharge passage 11 at the moment when the discharge of the electrode slurry, which has been stopped, is resumed, an excessive amount of the electrode slurry is discharged. Due to this, the front side 22(a) of the holding part 22 has a coating thickness thickening as an excessive amount of electrode slurry is discharged, and the rear side 22(b) of the holding part 22 stops discharging the electrode slurry. As a result, the coating thickness decreases rapidly. As such, when using the conventional electrode slurry discharging device, it is difficult to uniformly coat the electrode having a structure in which the holding part 22 and the uncoated part 23 are repeated.
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[6]
An object of the present invention is to provide an electrode slurry coating apparatus and method including a pressure regulating member as devised to solve the above problems.
means of solving the problem
[7]
The present invention provides an electrode slurry coating apparatus. In one example, the electrode slurry coating apparatus according to the present invention comprises: an electrode slurry discharge passage for discharging the electrode slurry through a slit formed at the interface between the first and second dies; an electrode slurry storage tank capable of fluid connection with the electrode slurry discharge passage and storing the electrode slurry under a positive pressure condition therein; and a positive pressure on/off valve positioned on a flow path through which the electrode slurry discharge flow path and the electrode slurry storage tank are fluidly connected, and whose opening and closing is determined by a difference between the pressure of the electrode slurry discharge flow path and the internal pressure of the electrode slurry storage tank.
[8]
In a specific example, the electrode slurry discharge passage and the electrode slurry storage tank have a structure that directly faces each other with a positive pressure on/off valve interposed therebetween.
[9]
In one example, the positive pressure on/off valve has a structure that is opened when the pressure of the electrode slurry discharge passage is greater than the internal pressure of the electrode slurry storage tank.
[10]
In a specific example, the positive pressure on/off valve has a structure including a shielding member supported by the elastic force of an elastic body, and when the pressure of the electrode slurry discharge flow path and the force pressing the shielding member exceed a preset reference value, the shielding member is an open structure.
[11]
In another specific example, a sensor for measuring the internal pressure of the electrode slurry discharge passage is further included, and when the pressure measured by the pressure sensor exceeds a predetermined reference value, the positive pressure on/off valve is opened.
[12]
In one example, the electrode slurry storage tank further includes an electrode slurry discharge flow path for discharging the stored electrode slurry when the internal pressure of the electrode slurry storage tank exceeds a predetermined reference value.
[13]
In a specific example, the electrode slurry discharge passage is fluidly connected to the electrode slurry discharge passage.
[14]
In one example, the electrode slurry discharged through the electrode slurry discharge passage has a structure for discharging the electrode slurry on the current collector layer moving by a conveyor.
[15]
In another example, the electrode slurry coating apparatus further includes a discharge control pump for controlling the discharge amount of the electrode slurry through the discharge passage of the electrode slurry.
[16]
In one example, the electrode slurry coating apparatus further includes a discharge blocking member for controlling the opening and closing of the discharge passage of the electrode slurry.
[17]
In a specific example, the discharge blocking member has a structure formed at the end of the discharge passage of the electrode slurry.
[18]
[19]
In addition, the present invention provides an electrode coating method using the electrode slurry coating apparatus described above. In one example, the electrode slurry coating method according to the present invention comprises discharging the electrode slurry on the current collector layer through a slit-type electrode slurry discharge passage formed at the interface between the first and second dies. A coating method comprising: initiating discharging of an electrode slurry; and stopping the discharging of the electrode slurry at regular intervals, but maintaining the pressure of the discharged slurry at a positive pressure by the pressure regulating member formed on the slit-type discharging flow path.
[20]
In one example, the pressure adjusting member may include: an electrode slurry storage tank that is fluidly connectable to the electrode slurry discharge passage and stores the electrode slurry under a positive pressure condition therein; and a positive pressure on/off valve positioned on a flow path through which the electrode slurry discharge flow path and the electrode slurry storage tank are fluidly connected, and whose opening and closing is determined by a difference between the pressure of the electrode slurry discharge flow path and the internal pressure of the electrode slurry storage tank.
[21]
In a specific example, the positive pressure on/off valve is opened when the pressure of the electrode slurry discharge passage is greater than the internal pressure of the electrode slurry storage tank.
Effects of the Invention
[22]
Since the electrode slurry coating apparatus and method according to the present invention include a pressure adjusting member, it is possible to discharge the electrode slurry at a constant pressure even when the holding part and the uncoated part are repeatedly formed on the current collector layer.
Brief description of the drawing
[23]
1 is a schematic diagram illustrating a process of discharging an electrode slurry on a current collector layer using a conventional electrode slurry coating apparatus.
[24]
2 is a schematic diagram illustrating a process of discharging electrode slurry on a current collector layer using an electrode slurry coating apparatus according to an embodiment of the present invention.
[25]
3 and 4 are schematic views showing the opening and closing process of the pressure regulating member according to an embodiment of the present invention.
[26]
5 is a schematic diagram illustrating an electrode slurry coating process according to an electrode slurry coating method according to an embodiment of the present invention.
Best mode for carrying out the invention
[27]
Hereinafter, the present invention will be described in detail. Prior to this, the terms or words used in the present specification and claims are not to be construed as being limited to their ordinary or dictionary meanings, and the inventor must properly understand the concept of the term in order to best describe his invention. It should be interpreted as meaning and concept consistent with the technical idea of ​​the present invention based on the principle that it can be defined in
[28]
[29]
The present invention relates to an electrode slurry coating apparatus, and in one embodiment, the electrode slurry coating apparatus,
[30]
an electrode slurry discharge passage for discharging the electrode slurry through a slit formed at an interface between the first and second dies;
[31]
an electrode slurry storage tank capable of fluid connection with the electrode slurry discharge passage and storing the electrode slurry under a positive pressure condition therein; and
[32]
The electrode slurry discharge flow path and the electrode slurry storage tank are located on the fluid flow path, and include a positive pressure on/off valve whose opening and closing is determined by a difference between the pressure of the electrode slurry discharge flow path and the internal pressure of the electrode slurry storage tank.
[33]
The electrode slurry discharge passage has a slit-type structure, and in a structure in which two or more blocks are combined, the electrode slurry discharge passage refers to a passage through which the electrode slurry is discharged through an interface between the blocks.
[34]
The electrode slurry coating apparatus continuously coats the electrode slurry on the current collector layer moving in one direction. When coating on the current collector layer by using the electrode slurry coating device, discharging may be performed in a repeating manner of the uncoated part and the holding part in the MD direction (Machine Direction). In this case, the electrode slurry coating device has to repeat discharging and stopping the electrode slurry. However, when the electrode slurry coating apparatus resumes coating of the stopped electrode slurry, an excessive load is applied to the electrode slurry discharge channel. When an excessive load is applied to the electrode slurry discharge flow path, the electrode slurry is excessively discharged to the coating starting portion of the holding part. The excessively discharged electrode slurry causes a phenomenon in which the loading amount of the electrode slurry becomes non-uniform, which leads to product failure. In the present invention, by including a pressure maintaining member for maintaining a constant pressure of the electrode slurry discharge passage, these problems are solved at once. The pressure maintaining member has a structure including the electrode slurry storage tank and the positive pressure on/off valve described above.
[35]
In one embodiment, the electrode slurry discharge flow path and the electrode slurry storage tank have a structure that directly faces each other with a positive pressure on/off valve interposed therebetween. The electrode slurry storage tank according to the present invention has a structure that is directly connected to the electrode slurry discharge flow path with the positive pressure on/off valve interposed therebetween. When the fluid connection line is formed over a certain distance, there is a limitation in that it is difficult to immediately react to the pressure change of the electrode slurry discharge passage. Therefore, in the present invention, the positive pressure on/off valve becomes a part of the structure forming the electrode slurry discharge flow path. Through this, in the present invention, by reflecting the pressure difference between the electrode slurry discharge passage and the electrode slurry storage tank, immediate pressure control is possible.
[36]
In one embodiment, the positive pressure on/off valve has a structure that is opened when the pressure of the electrode slurry discharge passage is greater than the internal pressure of the electrode slurry storage tank. When coating of the stopped electrode slurry is resumed in the electrode slurry coating apparatus, an excessive load is applied to the electrode slurry discharge channel and the electrode slurry is discharged in excess. In the present invention, an excessive load applied to the electrode slurry discharge passage can be effectively eliminated. That is, when an excessive load is applied to the electrode slurry discharge passage, the positive pressure on/off valve is opened, and a portion of the electrode slurry present in the electrode slurry discharge passage flows out toward the electrode slurry storage tank. Through this, the distance load on the electrode slurry discharge passage is eliminated.
[37]
In one specific example, the positive pressure on/off valve has a structure including a shielding member supported by the elastic force of an elastic body, and when the pressure of the electrode slurry discharge passage and the force pressing the shielding member exceed a preset reference value, the The shielding member has an open structure. In this case, the positive pressure on/off valve includes a shielding member supported by a spring or a hinge structure to which a spring is fastened. Through this, the present invention can control the opening and closing of the static pressure on-off valve in a non-powered manner, and does not require a sensor for measuring the internal pressure of the electrode slurry discharge passage.
[38]
In another specific embodiment, the electrode slurry coating apparatus according to the present invention further comprises a sensor for measuring the internal pressure of the electrode slurry discharge passage, and when the pressure measured by the pressure sensor exceeds a predetermined reference value , a structure that opens the positive pressure on/off valve. In this case, a pressure sensor for measuring the pressure of the electrode slurry discharge flow path is formed, thereby controlling the operation of the positive pressure on/off valve.
[39]
In one specific embodiment, the electrode slurry storage tank further includes an electrode slurry discharge flow path for discharging the stored electrode slurry when the internal pressure of the electrode slurry storage tank exceeds a predetermined reference value. The electrode slurry storage tank has a structure in which the electrode slurry is filled to a certain level, and through this, for example, an internal pressure of 14 kgf is maintained. When the pressure of the electrode slurry discharge passage exceeds 14 kgf, the positive pressure on/off valve is opened. As the positive pressure on/off valve is opened, a portion of the electrode slurry located in the electrode slurry discharge flow path moves to the electrode slurry storage tank. Through this, the pressure of the electrode slurry discharge passage is reduced. However, the internal pressure of the electrode slurry storage tank increases due to the incoming electrode slurry. In order to solve this problem, the slurry storage tank may have a structure in which an electrode slurry discharge passage is formed on one lower side. The above-described positive pressure on/off valve may be additionally formed on the electrode slurry discharge passage.
[40]
For example, the slurry storage tank may have a structure in which a pressure sensor for measuring an internal pressure is formed, and when the pressure measured by the pressure sensor exceeds a reference value, the electrode slurry discharge flow path is opened. Alternatively, an opening/closing valve having a structure including a shielding member supported by an elastic force of an elastic body is positioned on the electrode slurry discharge passage. The opening/closing valve to which such an elastic body is applied has an advantage that a separate sensor and a control unit for opening and closing the valve are not required.
[41]
In one embodiment, the electrode slurry discharge passage has a structure in fluid connection with the electrode slurry discharge passage. A method of disposing of the discharged electrode slurry from the slurry storage tank is also possible. However, it is possible to reuse the discharged electrode slurry by fluidly connecting the electrode slurry discharge passage with the electrode slurry discharge passage.
[42]
In one embodiment, the electrode slurry discharged through the electrode slurry discharge passage has a structure for discharging the electrode slurry on the current collector layer moving by a conveyor. The current collector layer may have a structure formed of aluminum foil or copper foil. For example, the current collector layer moves in one direction along a conveyor, and the electrode slurry coating device discharges the electrode slurry so that the holding part and the uncoated part are repeated on the current collector layer.
[43]
In one specific embodiment, the electrode slurry coating apparatus further includes a discharge control pump for controlling the discharge amount of the electrode slurry through the discharge flow path of the electrode slurry. The discharge control pump repeatedly performs a process of pressurizing the electrode slurry to be discharged and a process of stopping the pressurization. Through this, the electrode slurry coating apparatus according to the present invention discharges the electrode slurry so that the holding part and the uncoated part are repeated on the current collector layer.
[44]
In another specific embodiment, the electrode slurry coating apparatus further includes a discharge blocking member for controlling the opening and closing of the discharge passage of the electrode slurry. The discharge blocking member is formed, for example, in the form of a bar blocking the slit of the electrode slurry discharge passage. When the discharge blocking member closes the electrode slurry discharge passage, discharge of the electrode slurry by the electrode slurry coating device is stopped. Through this, the electrode slurry coating apparatus according to the present invention discharges the electrode slurry so that the holding part and the uncoated part are repeated on the current collector layer. For example, the discharge blocking member has a structure formed at the end of the discharge passage of the electrode slurry.
[45]
[46]
The present invention also provides an electrode slurry coating method using the electrode slurry coating apparatus described above. In one embodiment, the electrode slurry coating method according to the present invention includes discharging the electrode slurry on the current collector layer through a slit-type electrode slurry discharge passage formed at the interface between the first and second dies. In the slurry coating method,
[47]
initiating electrode slurry discharge; And repeating the step of stopping the discharge of the electrode slurry at regular intervals,
[48]
The pressure of the slurry discharged by the pressure adjusting member formed on the slit-type discharge passage is maintained at a positive pressure.
[49]
In the present invention, starting electrode slurry discharge; And by repeating the step of stopping discharging the electrode slurry at regular intervals, the electrode slurry may be coated on the current collector layer in a pattern in which the holding portion and the uncoated portion are repeated in the MD direction. In this case, the electrode slurry coating method according to the present invention needs to repeat discharging and stopping the electrode slurry. However, when the electrode slurry is coated, an excessive load is applied to the electrode slurry discharge channel when the discharge of the electrode slurry, which has been stopped, is resumed. An excessive load on the electrode slurry discharge flow path results in excessive discharge of the electrode slurry to the coating starting portion of the holding part. In the present invention, by including a pressure maintaining member for maintaining a constant pressure of the electrode slurry discharge passage, these problems are solved at once.
[50]
In one embodiment, the pressure regulating member may include: an electrode slurry storage tank that is fluidly connectable to the electrode slurry discharge passage and stores the electrode slurry under a positive pressure condition therein; and a positive pressure on/off valve positioned on a flow path through which the electrode slurry discharge flow path and the electrode slurry storage tank are fluidly connected, and whose opening and closing is determined by a difference between the pressure of the electrode slurry discharge flow path and the internal pressure of the electrode slurry storage tank.
[51]
In a specific embodiment, the positive pressure on/off valve has a structure that is opened when the pressure of the electrode slurry discharge passage is greater than the internal pressure of the electrode slurry storage tank. In the case of restarting the coating of the stopped electrode slurry in the electrode slurry coating method, an excessive load is applied to the electrode slurry discharge channel and the electrode slurry is discharged in excess. In the present invention, an excessive load applied to the electrode slurry discharge passage can be effectively eliminated. That is, when an excessive load is applied to the electrode slurry discharge passage, the positive pressure on/off valve is opened, and a portion of the electrode slurry present in the electrode slurry discharge passage flows out toward the electrode slurry storage tank. Through this, the distance load on the electrode slurry discharge passage is eliminated.
[52]
In one specific example, the positive pressure on/off valve has a structure including a shielding member supported by the elastic force of an elastic body, and when the pressure of the electrode slurry discharge passage and the force pressing the shielding member exceed a preset reference value, the The shielding member has an open structure. When the static pressure on/off valve has a structure including a shielding member supported by an elastic force of an elastic body, the static pressure on/off valve includes a shielding member supported by a spring or a hinge structure to which a spring is fastened. Through this, the present invention can control the opening and closing of the static pressure on-off valve in a non-powered manner, and has an advantage in that it does not require a sensor for measuring the internal pressure of the electrode slurry discharge passage.
[53]
In another specific embodiment, the electrode slurry coating method according to the present invention further includes a sensor for measuring the internal pressure of the electrode slurry discharge passage, and when the pressure measured by the pressure sensor exceeds a predetermined reference value , a structure that opens the positive pressure on/off valve.
[54]
In one embodiment, the electrode slurry storage tank further includes an electrode slurry discharge flow path for discharging the stored electrode slurry when the internal pressure of the electrode slurry storage tank exceeds a predetermined reference value. In addition, the electrode slurry discharge passage has a structure in fluid connection with the electrode slurry discharge passage. A method of disposing of the discharged electrode slurry from the slurry storage tank is also possible. However, it is possible to reuse the discharged electrode slurry by fluidly connecting the electrode slurry discharge passage with the electrode slurry discharge passage.
[55]
In the present invention, the description of the electrode slurry coating apparatus mentioned above is also applicable to the electrode slurry coating method, and overlapping specific descriptions are omitted.
[56]
[57]
Hereinafter, the present invention will be described in more detail with reference to drawings and examples.
[58]
[59]
(First embodiment)
[60]
2 is a schematic diagram illustrating a process of discharging electrode slurry on a current collector layer using an electrode slurry coating apparatus according to an embodiment of the present invention. Referring to FIG. 2 , the electrode slurry coating apparatus has a structure in which an electrode slurry discharge channel 111 for discharging the electrode slurry 121 through a slit formed at an interface between two dies is formed. In addition, an electrode slurry supply passage 112 is fluidly connected to the slurry discharge passage 111 , and the electrode slurry 121 is supplied therethrough. The current collector layer 130 formed of the metal foil passes through the front of the electrode slurry discharge passage 111 through a conveyor (not shown) driven by the rotating roller 140 . The discharged electrode slurry is discharged on the current collector layer 130 . The structure shown in FIG. 2 is a structure in which the holding part 122 and the uncoated part 123 are repeatedly formed on the current collector layer 130 , and the electrode slurry coating apparatus repeats discharging and stopping of the electrode slurry. However, an excessive load is applied to the electrode slurry discharge passage 111 at the moment when the discharge of the electrode slurry, which has been stopped, is resumed, an excessive amount of the electrode slurry may be discharged.
[61]
In the present invention, a pressure regulating member for maintaining a constant load or pressure applied to the electrode slurry discharge passage 111 is included. The pressure control member includes an electrode slurry storage tank 150 filled with the electrode slurry 120 to maintain the internal pressure under a positive pressure condition, and the pressure of the electrode slurry discharge passage 111 and the electrode slurry storage tank 150 . and a positive pressure on/off valve 151 whose opening and closing is determined by the difference between internal pressures. The electrode slurry storage tank 150 can be fluidly connected to the electrode slurry discharge passage 111 , and stores the electrode slurry 120 therein under a positive pressure condition. In addition, the positive pressure on/off valve 151 is located on a flow path through which the electrode slurry discharge flow path 111 and the electrode slurry storage tank 150 are fluidly connected, and the pressure of the electrode slurry discharge flow path 111 and the electrode slurry storage tank ( 150) It is a structure in which opening and closing is determined by the difference between internal pressures.
[62]
Specifically, the electrode slurry discharge passage 111 and the electrode slurry storage tank 150 directly face each other with the positive pressure on/off valve 151 interposed therebetween. In addition, the positive pressure opening/closing valve 151 has a structure that is opened when the pressure of the electrode slurry discharge passage 111 is greater than the internal pressure of the electrode slurry storage tank 150 .
[63]
[64]
(Second embodiment)
[65]
3 and 4 are schematic views showing the opening and closing process of the pressure regulating member according to an embodiment of the present invention. Referring to FIG. 3 , the pressure regulating member according to the present invention includes an electrode slurry storage tank 250 with an open top surface, a positive pressure on/off valve 251 covering the top surface of the electrode slurry storage tank 250 , and the electrode It includes an electrode slurry discharge flow path 260 formed on one lower side of the slurry storage tank 250 . The positive pressure on/off valve 251 has a structure including a plate-shaped shielding member supported by the elastic force of an elastic body (eg, a spring). Through this, the positive pressure on/off valve 251 is opened when the pressure of the electrode slurry discharge passage is greater than the internal pressure of the electrode slurry storage tank 250 .
[66]
Referring to FIG. 4 , the positive pressure on/off valve 251 is opened when the pressure of the electrode slurry discharge channel is greater than the internal pressure of the electrode slurry storage tank 250 . The electrode slurry storage tank 250 maintains an internal pressure of, for example, 14 kgf in a state in which the electrode slurry 220 is filled. When the pressure of the electrode slurry discharge passage exceeds 14 kgf, the pressure of the electrode slurry discharge passage is transmitted and the positive pressure on/off valve 251 is opened while pushing. As the positive pressure on/off valve 251 is opened, a portion of the electrode slurry located in the electrode slurry discharge passage moves to the electrode slurry storage tank 250 . Through this, the pressure of the electrode slurry discharge passage is reduced.
[67]
In addition, the slurry storage tank 250 has a structure in which an electrode slurry discharge flow path 260 is formed on one lower side. A discharge pump 261 is formed on the electrode slurry discharge passage 260 . As mentioned above, the internal pressure of the electrode slurry storage tank 250 increases due to the electrode slurry flowing in while the positive pressure on/off valve 251 is opened. When the internal pressure of the electrode slurry storage tank 250 increases, a portion of the electrode slurry inside is discharged to the slurry discharge channel 260 by the discharge pump 261 . It is also possible to form a separate static pressure on-off valve instead of the discharge pump 261 .
[68]
[69]
(Third embodiment)
[70]
5 is a schematic diagram illustrating an electrode slurry coating process according to an electrode slurry coating method according to an embodiment of the present invention. Referring to FIG. 5 , in the electrode slurry coating method according to the present invention, the electrode slurry 321 is discharged on the current collector layer 330 through the slit-type electrode slurry discharge passage 311 formed at the interface between two dies. including the steps of The electrode slurry 321 is supplied through the electrode slurry supply passage 312 . In addition, in the discharging of the electrode slurry 321 , starting the discharging of the electrode slurry 321 and stopping discharging the electrode slurry 321 are repeated at regular intervals. At this time, the pressure of the electrode slurry 321 discharged by the pressure adjusting member formed on the slit-type discharge passage 311 is maintained at a positive pressure. The pressure regulating member is disposed on the lower side of the electrode slurry storage tank 350 having an open top surface, a positive pressure on/off valve 351 covering the top surface of the electrode slurry storage tank 350 , and the electrode slurry storage tank 350 . and the formed electrode slurry discharge flow path 360 . The current collector layer 330 is positioned on a conveyor moving by the rotating roller 340 . The electrode slurry is coated on the current collector layer 330 so that the holding part 322 and the uncoated part 323 are repeated at regular intervals.
[71]
In addition, the electrode slurry 320 is filled in the electrode slurry storage tank 350 to maintain a constant pressure. When the pressure of the electrode slurry discharge passage 3111 increases, the positive pressure on/off valve 351 is opened and a portion of the electrode slurry 321 existing in the electrode discharge passage 311 flows into the electrode slurry storage tank 350 to control the pressure. do. When the pressure in the electrode slurry storage tank 350 exceeds a certain level, a portion of the electrode slurry 320 filled therein is discharged to the electrode slurry discharge channel 360 via the discharge pump 361 .
[72]
In some cases, the electrode slurry discharged to the electrode slurry discharge passage 360 ​​is recovered to the electrode slurry discharge passage 311 or the electrode slurry supply passage 312 again.
[73]
[74]
Above, the present invention has been described in more detail with reference to drawings and examples. However, since the configuration described in the drawings or embodiments described in the present specification is only one embodiment of the present invention and does not represent all the technical spirit of the present invention, various equivalents and It should be understood that there may be variations.
[75]
[76]
(Explanation of symbols)
[77]
11, 111, 311: electrode slurry discharge flow path
[78]
12, 112, 312: electrode slurry supply flow path
[79]
21, 121, 220, 320, 321: electrode slurry
[80]
22, 22(a), 22(b), 122, 322: electrode slurry coating area (holding part)
[81]
23, 123, 323: electrode slurry uncoated area (uncoated area)
[82]
30, 130, 330: current collector layer
[83]
40, 140, 340: roller
[84]
150, 250, 350: electrode slurry storage tank
[85]
151, 251, 351: static pressure on-off valve
[86]
260, 360: electrode slurry discharge flow path
[87]
261, 361: discharge pump

WE CLAIM

[Claim 1]an electrode slurry discharge passage for discharging the electrode slurry through a slit formed at an interface between the first and second dies; an electrode slurry storage tank capable of fluid connection with the electrode slurry discharge passage and storing the electrode slurry under a positive pressure condition therein; and a positive pressure on/off valve positioned on a flow path through which the electrode slurry discharge flow path and the electrode slurry storage tank are fluidly connected, and whose opening and closing is determined by the difference between the pressure of the electrode slurry discharge flow path and the internal pressure of the electrode slurry storage tank. Device.
[Claim 2]
The electrode slurry coating apparatus according to claim 1, wherein the electrode slurry discharge passage and the electrode slurry storage tank directly face each other with a positive pressure on/off valve interposed therebetween.
[Claim 3]
The electrode slurry coating apparatus according to claim 1, wherein the positive pressure on/off valve is opened when the pressure of the electrode slurry discharge channel is greater than the internal pressure of the electrode slurry storage tank.
[Claim 4]
The method of claim 1, wherein the positive pressure on/off valve has a structure including a shielding member supported by an elastic force of an elastic body, and when the pressure of the electrode slurry discharge flow path and the force pressing the shielding member exceed a preset reference value, the The shielding member is an electrode slurry coating device having an open structure.
[Claim 5]
The electrode slurry coating according to claim 1, further comprising a sensor for measuring the internal pressure of the electrode slurry discharge passage, wherein when the pressure measured by the pressure sensor exceeds a predetermined reference value, the positive pressure on/off valve is opened. Device.
[Claim 6]
The electrode slurry coating apparatus according to claim 1, wherein the electrode slurry storage tank further comprises an electrode slurry discharge channel for discharging the stored electrode slurry when the internal pressure of the electrode slurry storage tank exceeds a predetermined reference value.
[Claim 7]
The electrode slurry coating apparatus according to claim 6, wherein the electrode slurry discharge passage is fluidly connected to the electrode slurry discharge passage.
[Claim 8]
The electrode slurry coating apparatus according to claim 1, wherein the electrode slurry coating apparatus further comprises a discharge control pump for controlling the discharge amount of the electrode slurry through the discharge passage of the electrode slurry.
[Claim 9]
According to claim 1, wherein the electrode slurry coating apparatus, electrode slurry coating apparatus further comprising a discharge blocking member for controlling the opening and closing of the discharge passage of the electrode slurry.
[Claim 10]
The electrode slurry coating apparatus according to claim 9, wherein the discharge blocking member has a structure formed at an end of the discharge passage of the electrode slurry.
[Claim 11]
A method for coating an electrode slurry comprising discharging an electrode slurry on a current collector layer through a slit-type electrode slurry discharge passage formed at an interface between first and second dies, the method comprising: initiating discharging of the electrode slurry; and repeating the step of stopping the discharging of the electrode slurry at regular intervals, but maintaining the pressure of the slurry discharged by a pressure adjusting member formed on the slit-type discharge passage at a positive pressure.
[Claim 12]
12. The method of claim 11, wherein the pressure adjusting member comprises: an electrode slurry storage tank that is fluidly connectable to the electrode slurry discharge passage and stores the electrode slurry under a positive pressure condition therein; and a positive pressure on/off valve positioned on a flow path through which the electrode slurry discharge flow path and the electrode slurry storage tank are fluidly connected, and whose opening and closing is determined by the difference between the pressure of the electrode slurry discharge flow path and the internal pressure of the electrode slurry storage tank. Way.
[Claim 13]
The electrode slurry coating method according to claim 12, wherein the positive pressure on/off valve is opened when the pressure of the electrode slurry discharge channel is greater than the internal pressure of the electrode slurry storage tank.