Patent Description:
The present invention relates to a notching apparatus and method for an electrode substrate, and more particularly, to a notching apparatus and method for an electrode substrate, which can improve a conventional problem of contamination of an electrode current collector by forming a punching oil supply hole in a punch and applying the punching oil to a wall surface of the punch through the hole, and can also discharge foreign objects generated when punching an electrode through the hole formed in the punch.

With the explosive increase in technological development and demand for mobile devices and automobiles, more research is being conducted on a secondary battery with high energy density, discharge voltage and excellent output stability. Such a secondary battery generally has a structure which includes an electrode assembly having a structure in which electrodes (cathode and anode) and a separation membrane are alternately stacked, an electrolyte for moving ions to the electrodes, and a case that accommodates the electrode assembly and the electrolyte. Further, a manufacturing process of the secondary battery is roughly divided into an electrode plate process for manufacturing an anode and a cathode, an assembly process for manufacturing the anode and the cathode as an electrode assembly and inserting the electrode assembly into a case together with the electrolyte, and a formation machine for activating the ionic migration of the electrode assembly to have electricity. The electrode plate process, the assembly process and the formation process are each divided into individual detailed machines.

The electrode plate process includes a mixing process of adding and mixing a conductive material and a binder to the active material, a coating process of applying the mixed slurry composition onto a current collector, a press process of surface-pressing the current collector applied with the slurry composition, a slitting process of cutting the electrode manufactured by adhering the slurry composition to the surface of the current collector to fit the size, and a notching process for shearing to form an electrode tab on one end of the non-coated part of the cut electrode, and the like. At this time, the slitting process of cutting the electrode substrate applied with the active material on the surface of the current collector to fit the size, and the notching process of shearing to form an electrode tab on one end of the non-coated part of the cut electrode may be performed sequentially or simultaneously.

That is, the electrode substrate continuously provided at a standardized size passes through the slitting apparatus and the notching apparatus and is cut and machined to have a predetermined shape (for example, a shape in which an electrode tab protrudes to one side or the other side). The slitting apparatus and the notching apparatus may be configured separately, or may be configured so that cutting and machining are performed simultaneously by a single apparatus. Therefore, the slitting process and the notching process may be performed by the same punching apparatus, or may be performed by each of the slitting apparatus and the notching apparatus. At this time, the notching apparatus can be configured with a punch, a die, or the like.

<FIG> is a side view of a conventional notching apparatus. For example, the notching apparatus may be configured, as shown in <FIG>, to include a die member <NUM> including a die holder <NUM> and a die plate <NUM> (a sub-die plate 12a, and a main die plate 12b); and a punch member <NUM> that includes a punch holder <NUM>, a punch plate <NUM> (a sub-punch plate 22a and a main punch plate 22b) and a punch <NUM>, and moves up and down toward the die member <NUM> to shear one end of the electrode.

On the other hand, when the electrode notching process of a normal secondary battery is performed, a foil portion (current collector) of the electrode is burned to the notching apparatus, which inevitably causes problems such as poor punching and disconnection. <FIG> is a schematic diagram showing an aspect in which the electrode substrate is applied with punching oil before the electrode notching process. To improve the problem described above, the punching oil is directly applied to the electrode substrate <NUM>, separately before the notching process using the notching apparatus <NUM> as shown in <FIG>. That is to say, conventionally, through a method in which after both sides of the electrode substrate <NUM> conveyed through conveying rolls <NUM> are applied with the punching oil supplied by a punching oil supply unit <NUM>, the electrode substrate <NUM> supplied with the punching oil is conveyed to the notching apparatus <NUM> to perform the notching process, the problem of the foil portion (current collector) of electrode burned to the notching apparatus is prevented.

However, in this case, the foil portion (current collector) of the electrode is contaminated by the punching oil, causing problems such as poor welding. Further, the punching oil is not supplied and injected into the notching apparatus, causing a problem that the notching process is not smoothly performed.

Therefore, there is a demand for a measure in which the punching oil is supplied to prevent the foil portion (current collector) of the electrode from being burned to the notching apparatus, causing problems such as poor punching and disconnection, and the punching oil is not directly applied to the electrode substrate to prevent contamination of the foil portion (current collector) of the electrode.

Document <CIT> discloses a punching mold for cutting lithium secondary battery electrode plates equipped with a punch lubricating and cooling means.

Accordingly, an object of the present invention is to provide a notching apparatus and method for an electrode substrate, which can solve the conventional problem of contamination of an electrode current collector by forming a punching oil supply hole in a punch and applying the punching oil to a wall surface of the punch through the punching oil supply hole, and can also discharge foreign objects generated when an electrode is punched through the hole formed in the punch.

In order to achieve the above object, the present invention provides a notching apparatus according to claim <NUM>.

Further, the present invention provides a notching method according to claim <NUM>.

Preferred embodiments are detailed in the dependent claims.

The notching apparatus and method for an electrode substrate according to the present invention has an advantage which can solve the conventional problem of contamination of an electrode current collector by forming a punching oil supply hole in a punch of the notching apparatus and applying the punching oil to a wall surface of the punch through the punching oil supply hole. Further, notching apparatus and method for an electrode substrate according to the present invention has an advantage which can also discharge foreign objects generated when an electrode is punched through the hole formed in the punch of the notching apparatus.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the present invention. The present invention may, however, be embodied in many different forms and, therefore, the present invention is not limited to the embodiments set forth below. Further, in order to explain the features of the present invention more clearly, it is made clear that the known parts deviating from the main configuration have been omitted from the drawings.

<FIG> is a side view of a notching apparatus according to one embodiment of the present invention. As shown in <FIG>, a notching apparatus <NUM> according to the present invention includes a die member <NUM> on which an electrode substrate is disposed. And, the notching apparatus <NUM> includes a punch member <NUM> provided with a punch <NUM> spaced apart from above the die member <NUM> and vertically moves toward the die member <NUM> side. One or more punching oil supply holes <NUM> for applying the punching oil to the outer surface of the punch <NUM> are provided (or formed by being perforated) on the wall surface of the punch <NUM>.

When the electrode notching process of the conventional secondary battery is performed, the current collector of the electrode is burned on to the notching apparatus (or notching mold), causing problems such as poor punching and disconnection. In order to improve this, as shown in <FIG>, before the notching process using the notching apparatus <NUM>, the electrode substrate <NUM> is separately applied directly with punching oil. In other words, in the prior art, the problem of the electrode current collector burned to the notching apparatus is prevented through the method in which both sides of the electrode substrate <NUM> conveyed through the conveying rolls <NUM> are applied with the punching oil supplied by the punching oil supply unit <NUM>, and then the electrode substrate <NUM> supplied with the punching oil is conveyed to the notching apparatus <NUM> to perform the notching apparatus <NUM>. However, in this case, the punching oil contaminates the current collector of the electrode, which causes problems such as poor welding, and causes a problem that the punching oil is not directly supplied and injected into the notching apparatus, and thus the notching process is not smoothly performed.

Accordingly, the present applicant suggests a technology that does not directly apply the punching oil to the electrode substrate to prevent contamination of the current collector of the electrode, while supplying the punching oil to prevent the current collector of the electrode from being burned to the notching apparatus and causing problems such as poor punching and disconnection.

A secondary battery generally has a structure which includes an electrode assembly having a structure in which electrodes (cathode and anode) and separation membranes are alternately stacked, an electrolyte for moving ions to the electrodes, and a case in which the electrode assembly and the electrolyte are accommodated. The manufacturing process of the secondary battery can be broadly divided into an electrode plate process for manufacturing an anode and a cathode, an assembly process for manufacturing the anode and the cathode as an electrode assembly and then inserting the electrode assembly into a case together with an electrolyte, and a formation process which activates the ionic migration of the assembly electrode to have electricity. The electrode plate process, the assembly process and the formation process are each divided into separate detailed machines.

Among them, the electrode plate process includes a mixing process of adding and mixing a conductive material and a binder to the active material, a coating process of applying the mixed slurry composition onto the current collector, a press process of surface-pressing the current collector applied with the slurry composition, a slitting process of cutting the electrode manufactured by adhering the slurry composition to the surface of the current collector to fit the size, a notching process of shearing to form an electrode tab on one end of the non-coated part of the cut electrode, and the like. At this time, the slitting process of cutting the electrode substrate applied with the active material on the surface of the current collector to fit the size, and the notching process of shearing to form an electrode tab at one end of the non-coated part of the cut electrode may be performed sequentially or simultaneously.

Therefore, through the notching apparatus according to the present invention, both notching for shearing to form an electrode tab at one end of the non-coated part of the uncut electrode, and slitting for cutting the electrode to fit the size may be performed, and only notching for machining one end of the non-coated part of the cut electrode may also be performed.

The electrode substrate may be a conventional one that can be applied to the notching process, and may be, for example, one manufactured by coating and pressing the slurry composition, in which the active material, the conductive material and the binder are mixed, to one surface of the current collector. In addition, the electrode substrate may be divided into a holding part applied with the active material and a non-coated part in which the electrode tab is formed without being applied with the active material, and notching may be a process of shearing one end of the non-coated part. However, this is only an example, and it is obvious that works that can be performed in a normal secondary battery notching process can be performed.

The notching apparatus <NUM> according to the present invention will be specifically described with reference to <FIG>. In the notching apparatus <NUM> of the present invention, the die member <NUM> has continuously supplied electrode substrates (that is, workpiece) disposed thereon, and may include a die holder <NUM>, a die plate <NUM>(a sub-die plate 112a and a main die plate 112b) and the like. If desired, the main die plate 112b may be formed with a machining frame (the portion indicated by the broken line of 112b). Moreover, it is not necessary to include both the sub-die plate 112a and the main die plate 112b, and only one die plate among them may be provided. By such a die member <NUM>, it is possible to stably prevent or minimize the separation or drift of the workpiece during the machining operation. On the other hand, the sub-die plate 112a is detachably fixed to the die holder <NUM>, and since the die plates <NUM> of various standards may be exchanged for use, it is possible to improve workability and compatibility. Further, as shown in <FIG>, a buffer member may be interposed between the die holder <NUM> and the sub-die plate 112a, thereby reducing noise and vibration to improve the machining accuracy.

The punch member <NUM> is provided to be spaced above the die member <NUM>, moves up and down toward the die member <NUM>, and may include a punch holder <NUM> and a punch plate (<NUM>, a sub-punch plate 122a and a main punch plate 122b). Moreover, it is not necessary to include both the sub-punch plate 122a and the main punch plate 122b, and only one punch plate of them may be provided. On the other hand, since the sub-punch plate 122a is detachably fixed to the punch holder <NUM>, and punch plates <NUM> of various standards may be exchanged for use, thereby improving workability and compatibility. Also, if the punch <NUM> coupled to the lower end of the main punch plate 122b is damaged or needs to be replaced with a punch of another standard, the main punch plate 122b may be separated from the sub-punch plate 122a and then replaced with another main punch plate. Further, as shown in <FIG>, a buffer member may be interposed between the punch holder <NUM> and the sub-punch plate 122a, thereby reducing noise and vibration and thus improving machining accuracy.

The punch <NUM> is coupled to the lower end of the punch member <NUM>, moves up and down together with the punch member <NUM>, and directly machines a workpiece (an electrode substrate). That is, through the punch <NUM>, one or more of notching for shearing to form an electrode tab at one end of the non-coated part of the electrode and slitting for cutting the electrode to fit the size may be performed, and a work that requires separate punching may also be performed as necessary. In addition, the punch <NUM> machines the workpiece, while descending to the main die plate 112b of the die member <NUM> together with the punch member <NUM>, and also may perform machining by being inserted into the machining frame (the portion indicated by the broken line of 112b) that can be formed on the main die plate 112b as necessary.

The wall surface of the punch <NUM> is provided with (or formed by perforating) one or more punching oil supply holes <NUM>. This is to eliminate the problem (the current collector of the electrode is contaminated and causes problems such as poor welding) caused by directly applying the punching oil to the electrode substrate before the notching process, as described above. That is, according to the present invention, the punching oil is applied to the outer surface of the punch <NUM> through the punching oil supply hole <NUM>, and the application of the punching oil is preferably performed before the notching process starts. This is because the problem of contamination of the current collector of the electrode may be prevented or minimized. However, in consideration of repeated machining, additional subsequent application may be intermittently performed even after machining starts, and it is preferable that the application is performed in the state in which the punch <NUM> is separated from the die member <NUM> even in the case of subsequent application, in order to prevent or minimize the problem of continuous contamination of the electrode current collector. In addition, the punching oil may be applied to the outer surface of the punch <NUM>, but in the case of a punch having an opening at the bottom, the punching oil may also be applied to the inner surface of the punch as necessary.

One or more punching oil supply holes <NUM> may be provided on the wall surface of the punch <NUM>, and the number of punching oil supply holes <NUM> may be appropriately set in consideration of the size and area of punch, the number of repetitions of machining, and the like. On the other hand, although three punching oil supply holes <NUM> are formed in <FIG>, this is only an aspect. The size of the punching oil supply hole <NUM> is also not particularly limited, and it is clarified that this is also variable depending on the size and area of the punch <NUM>, the number of repetitions of machining, and the like. However, in an example, the punching oil supply hole <NUM> may have a diameter of <NUM> to <NUM>. Also, as an example, the punching oil supply hole <NUM> may be provided at a position <NUM> to <NUM> away from the lowermost end of the punch <NUM>.

The punching oil supply hole <NUM> may be connected to a punching oil supply line connected to a punching oil reservoir (if necessary, including a punching oil supply nozzle). Therefore, the punching oil may be conveyed sequentially through the punching oil reservoir and the punching oil supply line, and may be applied to the outer surface of the punch through the punching oil supply hole connected to the punching oil supply line. The supply of punching oil can then be controlled through a punching oil control valve. Therefore, it is possible not only to control the supply amount of the punching oil as well as the opening and closing through the punching oil control valve.

On the other hand, it is possible to blow air into the notching apparatus <NUM> and discharge foreign object such as dust generated during the notching process, through the punching oil supply hole <NUM> formed in the notching apparatus <NUM> of the present invention. Therefore, in this case, instead of the punching oil supply line, the air blow and foreign object suction line may be connected to the punching oil supply hole <NUM>.

However, in order to avoid inconvenience in which the air blow and foreign object suction line is connected to the punching oil supply hole <NUM> instead of the punching oil supply line, and then the punching oil supply line is connected to the punching oil supply hole <NUM>, the air blow and foreign object suction holes are also additionally provided on the wall surface of the punch <NUM>, in addition to the punching oil supply hole <NUM>. <FIG> is a side view of a notching apparatus according to the embodiment of the present invention. That is, as shown in <FIG>, a notching apparatus <NUM> according to the present invention includes not only a punching oil supply hole <NUM> but also one or more air blow and foreign object suction holes <NUM> on the wall surface of the punch <NUM>.

As described above, if the air blow and foreign object suction holes <NUM> are also provided on the wall surface of the punch <NUM>, there is an advantage that the foreign object may be immediately removed from the interior of the notching apparatus at the same time as punching. If the foreign object is not removed at the same time as punching, there is a possibility that the punching oil will mix with the foreign object to increase the resistance inside the notching apparatus. Therefore, it is preferable to separately form the air blow and foreign object suction hole <NUM>, rather than discharging the foreign object through the punching oil supply hole <NUM>, so that the punching oil supply hole <NUM>, and the air blow and foreign object suction hole <NUM> serve their original roles independently at the same time.

On the other hand, if the suction is performed after air is blown to the inside of the notching apparatus as described above, foreign object such as dust may be discharged to the outside of the notching apparatus. Furthermore, when air is blown to the inside of the notching apparatus, an air layer is formed between the die member <NUM> and the punch member <NUM> of the notching apparatus, which can even function as an air lubricant inside the notching apparatus.

As with the punching oil supply hole <NUM>, one or more air blow and foreign object suction holes <NUM> may be provided on the wall surface of the punch <NUM>, and the number of air blow and foreign object suction holes <NUM> may be appropriately set in consideration of the size and area of the punch, the number of repetitions of machining, and the like. On the other hand, although three air blow and foreign object suction holes <NUM> are formed in <FIG>, this is only an aspect. The size of the air blow and foreign object suction hole <NUM> is also not particularly limited, and it is obvious that this is also variable depending on the size and area of the punch <NUM>, the number of repetitions of machining, and the like. However, the air blow and foreign object suction hole <NUM> is preferably positioned below the punching oil supply hole <NUM> (that is, preferably positioned at the lower end on the basis of the reference the punching oil supply hole <NUM>) to quickly remove foreign object and form an air layer. Therefore, as an example, the air blow and foreign object suction hole <NUM> may be formed at a position away from the lowermost end of the punch <NUM> by <NUM> to <NUM> (at this time, the punching oil supply hole <NUM> may be formed at a position away from the lowermost end of the punch <NUM> by <NUM> to <NUM>).

<FIG> is a side view showing an aspect in which the punch is lowered and inserted into the machining frame in the notching apparatus according to another embodiment of the present invention. As described above, the punch <NUM> machines the workpiece, while descending to the main die plate 112b of the die member <NUM> together with the punch member <NUM>. As shown in <FIG>, at this time, when the punching oil supply hole <NUM>, the air blow and foreign object suction hole <NUM> are provided on the wall surface of the punch <NUM>, as shown in <FIG>, only the air blow and foreign object suction hole <NUM> of the punch <NUM> may be accommodated inside the main die plate 112b of the die member <NUM>. In other words, even if the punch <NUM> is lowered, the punching oil supply hole <NUM> is preferably not accommodated inside the main die plate 112b. That is, this is because the punching oil is applied to the outer surface of the punch <NUM> before machining, and the air blow and foreign object suction functions operate during machining.

<FIG> is a side cross-sectional view showing an aspect in which the punching oil supply line, and the air blow and foreign object suction line are connected to the punch of the notching apparatus according to the present invention, and <FIG> is a plan view showing a state in which the punching oil supply line, the air blow and foreign object suction line are connected to the punch of the notching apparatus according to the present invention. As described above, the punching oil supply hole <NUM> may be connected to the punching oil supply line connected to the punching oil reservoir, and can even include a punching oil supply nozzle if necessary at the time of connecting. More specifically described with reference to <FIG> and <FIG>, the punching oil may be conveyed sequentially through the punching oil reservoir (not shown), the punching oil supply line <NUM> and the punching oil supply nozzle <NUM>. The punching oil may be applied to the outer surface of the punch <NUM> through the punching oil supply hole <NUM> connected to the punching oil supply nozzle <NUM>. However, although <FIG> and <FIG> also show the punching oil supply nozzle <NUM>, this is only one embodiment, and therefore the punching oil supply line <NUM> may be directly connected to the punching oil supply hole <NUM>. Further, as shown in <FIG> and <FIG>, the punching oil supply hole <NUM> may also be formed on the opposite side of the punch <NUM>. Further, there is no particular restriction on the position of the punching oil reservoir.

Continuously referring to <FIG> and <FIG>, the air blow and foreign object suction nozzle <NUM> may be connected to the air blow and foreign object suction hole <NUM>, and the air blow and foreign object suction nozzle <NUM> may be connected with the air blow and foreign object suction line <NUM>. However, although air blow and foreign object suction nozzles <NUM> are shown in <FIG> and <FIG>, this is only an embodiment, and therefore it is obvious that air blow and foreign object suction lines <NUM> may be directly connected to the air blow and foreign object suction holes <NUM>. Further, it is obvious that the air blow and foreign object suction holes <NUM> may also be formed on the opposite side of the punch <NUM>, as shown in <FIG> and <FIG>.

Also, although <FIG> and <FIG> also show one punching oil supply nozzle <NUM> and one air blow and foreign object suction nozzle <NUM> on one side of the punch <NUM>, this is only an example shown for convenience of explanation, and it is obvious that the punching oil supply holes <NUM> and the air blow and foreign object suction holes <NUM> are provided to be suitable for the number of formations.

Next, a method for notching an electrode substrate according to the present invention will be described. Referring to <FIG> and <FIG> again, the notching method for the electrode substrate includes: (a) a step of supplying a punching oil through a punching oil supply hole <NUM> provided on the wall surface of the punch <NUM> of the punch member <NUM>, and applying the punching oil to an outer surface of the punch <NUM>, and (b) a step of lowering the punch member <NUM> to the die member <NUM> side on which the electrode substrate is disposed, and notching the electrode substrate with the punch <NUM> applied with the punching oil. Further, the punching oil may be sequentially conveyed through the punching oil reservoir and the punching oil supply line and applied to the outer surface of the punch <NUM> through the punching oil supply hole <NUM>.

The punching oil is applied to the outer surface of the punch <NUM>, and the application of the punching oil is preferably performed before the notching process of step (b) starts. By doing so, it is possible to prevent or minimize the direct application of the punching oil to the electrode substrate, thereby preventing or minimizing the problem of contamination of the current collector of the electrode. However, in consideration of repeated machining, additional subsequent applications may be performed intermittently while notching is being performed (similarly applied to the outer surface of the punch), and it is preferred that subsequent coating also be performed, while the punch <NUM> is spaced apart from the die member <NUM> to continuously prevent or minimize the problem of contamination of the electric collector of the electrodes (of course, it is possible to apply the punching oil to the outer surface of the punch <NUM> even during machining). Therefore, the present invention reveals that a process of applying the punching oil to the electrode substrate using a separate punching oil unit prior to the notching process as in the related art is eliminated (i.e., the punching oil does not contact the electrode substrate before the electrode substrate is placed in the notching apparatus or is notched). In addition, the punching oil may be applied to the outer surface of the punch <NUM>, but in the case of a punch having an opening at the bottom, the punching oil may also be applied to an inner surface of the punch as necessary.

On the other hand, the punching oil applied to the outer surface of the punch <NUM> through the punching oil supply hole <NUM> may be sequentially conveyed and supplied through the punching oil reservoir and the punching oil supply line. Also, the supply of punching oil may be controlled through a punching oil control valve. Therefore, it is possible to control not only opening and closing but also the supply amount of the punching oil through the punching oil control valve, and the supply amount of the punching oil may be controlled in consideration of the machining conditions or the like of the electrode substrate. Also, the punching oil may be applied onto the outer surface of the punch <NUM> in a spraying manner through the punching oil supply nozzle. The punching oil may be one commonly used in the industry, and the type thereof is not limited.

Meanwhile, the punch <NUM> further includes an air blow and foreign object suction hole <NUM>, in addition to the punching oil supply hole <NUM>, on its wall surface. Therefore, in this case, air is blown to the interior of the notching apparatus at the same time as the notching of the step (b), foreign object such as dust generated at the time of the notching may be discharged to the outside, and the air layer is formed between the die member <NUM> and the punch member <NUM> of the notching apparatus. When the foreign object such as dust is discharged to the outside at the same time as machining, it is possible to prevent or minimize the possibility that the punching oil and the foreign object are mixed to increase the resistance in the notching apparatus. Further, when an air layer is formed between the die member <NUM> and the punch member <NUM>, the air layer functions as an air lubricant in the notching apparatus, which is more advantageous for the notching process.

Claim 1:
A notching apparatus (<NUM>) for an electrode substrate (<NUM>), comprising:
a die member (<NUM>) on which the electrode substrate (<NUM>) is disposed; and
a punch member (<NUM>) provided with a punch (<NUM>) spaced apart from above the die member (<NUM>) and moving up and down toward the die member side,
wherein a wall surface of the punch (<NUM>) is provided with at least one or more air blow holes (<NUM>) to discharge foreign objects generated at the time of the notching to the outside,
characterized in that the at least one or more air blow holes (<NUM>) are also foreign object suction holes,
in that said air blow holes (<NUM>) are provided to form an air layer between the die member (<NUM>) and the punch member (<NUM>), and
in that the wall surface of the punch (<NUM>) is further provided with one or more punching oil supply holes (<NUM>) for applying a punching oil to an outer surface of the punch (<NUM>).