Patent Application
20250062311
This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0107763 filed in the Korean Intellectual Property Office on Aug. 17, 2023, the entire contents of which are incorporated herein by reference.
Embodiments relate to a manufacturing method of an electrode for a rechargeable battery.
Unlike primary batteries, rechargeable batteries are batteries that repeatedly charge and discharge. Small-capacity rechargeable batteries are used in small, portable electronic devices such as mobile phones, laptop computers, and camcorders, and high-capacity secondary batteries are used as power sources for driving motors in hybrid and electric vehicles.
For example, a rechargeable battery includes an electrode assembly that performs charging and discharging, a pouch that accommodates the electrode assembly, and an electrode terminal that electrically connects the electrode assembly and extends it to the outside of the pouch. The electrode assembly includes a winding type in which negative and positive electrode plates are wound on both sides with a separator therebetween, and a stacking type in which negative and positive electrode plates are stacked on both sides with a separator therebetween.
The electrode plate process for manufacturing an electrode plate includes a mixing step of mixing an active material slurry, a coating step of applying a coating portion of the active material slurry on a metal substrate, a pressing step of compressing the coating portion of the active material slurry, a notching step of cutting the metal substrate, and a slitting step.
In the coating step, loss occurs in the active material slurry and the metal substrate due to the derivation of conditions at the beginning of production, in the notching step, loss occurs in the active material and metal substrate due to the punching of the electrode plate. In the slitting step, wrinkles occur in the uncoated region, increasing the defect rate. Additionally, if changing the type of rechargeable battery, time loss occurs due to changing to a metal substrate of a different width and changing the coating die.
Embodiments include a method of manufacturing an electrode of a rechargeable battery. The method includes a first step of injection molding a plate-shaped electrode sheet in an injection mold with an electrode mixture that is input into an injection device, resulting in a molded electrode sheet, a second step of moving the molded electrode sheet onto a metal substrate and a third step of laminating the metal substrate and the molded electrode sheet.
In the third step, the metal substrate may be cut, the molded electrode sheet may be laminated on one surface of the metal substrate in a press device, and the molded electrode sheet may be laminated to another surface of the metal substrate.
In the third step, the metal substrate may be cut and the molded electrode sheet may be disposed on both sides of the metal substrate in a press device and laminated.
For a positive electrode, the electrode mixture may include a positive electrode active material, a binder, a conductive material, and a curing agent, and may have a ratio of positive electrode active material:binder:conductive material:curing agent is 96.9:1.8:2:2.
For a positive electrode, based on 100 wt % of the electrode mixture, the electrode mixture may include 85.0 wt % to 98.5 wt % of a positive electrode active material, 0.5 wt % to 5.0 wt % of a binder, 0.5 wt % to 5.0 wt % of a conductive material, and 0.5 wt % to 5.0 wt % of a curing agent.
The binder assists in the bonding of the positive electrode active material and the conductive material and to the metal substrate, and may be formed of one of polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, and fluorine rubber.
The conductive material may include a non-linear first conductive material and a linear second conductive material.
The non-linear first conductive material may include at least one of Denka black and carbon-based materials, wherein the Denka black and carbon-based materials include carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, thermal black, and Super-P.
The first conductive material may have an average particle diameter of 50 nm to 110 nm, the second conductive material may be a linear carbon nanotube (CNT) manufactured through a wet grinding process, and an average length of the linear carbon nanotube may be 1 μm to 5 μm.
The curing agent may include one of an epoxy-based resin and a phenol-based resin.
The epoxy-based resin may include at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol epoxy resin, phenolic novolac epoxy resin, cresol novolac epoxy resin, bisphenol A novolac epoxy resin, bisphenol F novolac epoxy resin, phenolic salicylic aldehyde novolac epoxy resin, cycloaliphatic epoxy resin, aliphatic chain epoxy resin, glycidyl ester type epoxy resin, and modified resins thereof.
The phenolic resin may include at least one of bisphenol F, bisphenol A, bisphenol S, polyvinyl phenol, phenol, cresol, alkyl phenol, catechol, novolac resin, and halide substitutes thereof.
In the second step, the electrode sheet, which may be molded and separated from the injection mold and then freely falls or may be moved by a gripper, is moved onto the metal substrate.
For a negative electrode, the electrode mixture may include 85.0 wt % to 98.5 wt % a negative electrode active material, 0.5 wt % to 5.0 wt % of a binder, 0.5 wt % to 5.0 wt % of a conductive material, and 0.5 wt % to 5.0 wt % of a curing agent.
In the first step, a rectangular space is formed with an upper mold and a lower mold of the injection mold and the electrode sheet is molded into a plate-shaped rectangular parallelepiped.
In the first step, an overall thickness of the electrode sheet may be uniformly molded.
In the first step, a chamfer is molded, in which a thickness becomes gradually thinner on an outer portion of one surface of the electrode sheet, by a convex round region at a corner of an inner space of a lower mold among an upper mold and the lower mold of the injection mold.
In the third step, the metal substrate is unwound and continuously supplied, and the electrode sheet is laminated and rewound on both sides of the metal substrate in the press device.
A manufacturing method of an electrode for a rechargeable battery according to embodiments of the present disclosure includes: a first step of injection molding a plate-shaped electrode sheet in an injection mold using an electrode mixture that is input into an injection device; a second step of moving the electrode sheet molded in the first step onto a metal substrate; and a third step of laminating the metal substrate and the electrode sheet.
In the third step, the metal substrate is cut, the electrode sheet may be laminated on one surface of the metal substrate in a press device, and the electrode sheet may be laminated to the other surface of the metal substrate.
In the third step, the metal substrate is cut, and the electrode sheet may be disposed on both sides of the metal substrate in the press device and laminated.
In the case of a positive electrode, the electrode mixture includes a positive electrode active material, a binder, a conductive material, and a curing agent, and may have a ratio of positive electrode active material:binder:conductive material:curing agent is 96.9:1.8:2:2.
In the case of a positive electrode, based on 100 wt % of the electrode mixture, the electrode mixture may include 85.0 wt % to 98.5 wt % of a positive electrode active material, 0.5 wt % to 5.0 wt % of a binder, 0.5 wt % to 5.0 wt % of a conductive material, and 0.5 wt % to 5.0 wt % of a curing agent.
The binder assists the bonding of the positive electrode active material and the conductive material and to the metal substrate, and may be formed of one of polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, and fluorine rubber.
The conductive material may include a non-linear first conductive material and a linear second conductive material.
The non-linear first conductive material may include at least one selected from the group consisting of and Denka black and carbon-based materials, such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, thermal black, and Super-P.
The first conductive material may have an average particle diameter of 50 nm to 110 nm, the second conductive material may be a linear carbon nanotube (CNT) manufactured through a wet grinding process, and the average length of the carbon nanotube may be 1 μm to 5 μm.
The curing agent may be formed of one of an epoxy-based resin and a phenol-based resin.
The epoxy resin may include at least one selected from the group consisting of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol epoxy resin, phenolic novolac epoxy resin, cresol novolac epoxy resin, bisphenol A novolac epoxy resin, bisphenol F novolac epoxy resin, phenolic salicylic aldehyde novolac epoxy resin, cycloaliphatic epoxy resin, aliphatic chain epoxy resin, glycidyl ester type epoxy resin, and modified resins thereof.
The phenolic resin may include at least one selected from the group consisting of bisphenol F, bisphenol A, bisphenol S, polyvinyl phenol, phenol, cresol, alkyl phenol, catechol, novolac resin, and halide substitutes thereof.
In the second step, the electrode sheet, which is molded and separated from the injection mold and then freely falls or is moved with a gripper, may be moved onto the metal substrate.
In the case of the negative electrode, based on 100 wt % of the electrode mixture, the electrode mixture may include 85.0 wt % to 98.5 wt % a negative electrode active material, 0.5 wt % to 5.0 wt % of a binder, 0.5 wt % to 5.0 wt % of a conductive material, and 0.5 wt % to 5.0 wt % of a curing agent.
In the first step, a rectangular space may be formed with the upper mold and the lower mold of the injection mold, and the electrode sheet may be molded into a plate-shaped rectangular parallelepiped.
In the first step, the overall thickness of the electrode sheet may be uniformly molded.
In the first step, a chamfer may be molded, in which the thickness becomes gradually thinner on the outer portion of one surface of the electrode sheet, by a convex round region at the corner of the inner space of the lower mold among the upper mold and the lower mold of the injection mold.
In the third step, the metal substrate may be unwound and continuously supplied, and the electrode sheet may be laminated and rewound on both sides of the metal substrate in the press device.
Features will become apparent to those of ordinary skill in the art by describing in detail exemplary embodiments with reference to the attached drawings, in which:
Example embodiments will now be described more fully hereinafter with reference to the accompanying drawings; however, they may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey exemplary implementations to those of ordinary skill in the art.
In the drawing figures, the dimensions of layers and regions may be exaggerated for clarity of illustration. It will also be understood that if a layer or element is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. Further, it will be understood that if a layer is referred to as being “under” another layer, it can be directly under, and one or more intervening layers may also be present. In addition, it will also be understood that if a layer is referred to as being “between” two layers, it can be the only layer between the two layers, or one or more intervening layers may also be present. Like reference numerals refer to like elements throughout.
Hereinafter, the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the disclosure are shown. As those of ordinary skill in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present disclosure. The drawings and description are to be regarded as illustrative in nature and not restrictive.
Referring to
If manufacturing a positive electrode, the electrode mixture M input into the injection device 10 may be configured to form a positive electrode. The positive electrode mixture M may include a positive electrode active material, a binder, a conductive material, and a curing agent, and these have a set ratio. For example, the positive electrode active material, binder, conductive material, and curing agent may have a ratio of 96.9:1.8:2:2.
In addition, the positive electrode mixture M may include, based on 100 wt % of the positive electrode mixture, 85.0 wt % to 98.5 wt % of a positive electrode active material, 0.5 wt % to 5.0 wt % of a binder, 0.5 wt % to 5.0 wt % of a conductive material, and 0.5 wt % to 5.0 wt % of a curing agent. The positive electrode active material is the part that acts as a positive electrode in the electrode. If the positive electrode active material is less than 86.0 wt %, the performance of the positive electrode active material may be lowered. By setting the maximum value to 98.5 wt %, it is possible to include a binder, conductive material, and curing agent.
The binder assists the bonding of the positive electrode active material and the conductive material to the metal substrate S2. If the binder is less than 0.5 wt %, injection molding of the electrode sheet S1 may be difficult because the bonding force is weak, and if the binder exceeds 5.0 wt %, the role of other components may be reduced.
For example, the binder may include one of polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, and fluorine rubber.
The conductive material may include a non-linear first conductive material and a linear second conductive material. The conductive material assists in the conductivity of the positive electrode active material and the metal substrate S2. If the conductive material is less than 0.5 wt %, the conductivity of the positive electrode active material and the metal sheet S2 may be reduced because the conductive assistance is weak, and if the conductive material exceeds 5.0 wt %, the role of other components may be reduced.
For example, the non-linear first conductive material may include at least one of Denka black and carbon-based materials, such as carbon black, acetylene black, Ketjen black, channel black, furnace black, lamp black, thermal black, and Super-P. The non-linear first conductive material may have an average particle diameter of 50 nm to 110 nm, and the second conductive material may be a linear carbon nanotube (CNT) manufactured through a wet grinding process. The average length of the carbon nanotube may be 1 μm to 5 μm.
The curing agent hardens the electrode mixture M in the injection mold 20, allowing the electrode mixture M to be separated from the injection mold 20 and moved to the electrode sheet S1.
The curing agent assists in molding the electrode mixture M into the electrode sheet S1. If the curing agent is less than 0.5 wt %, the moldability of the electrode sheet S1 may be reduced because the molding aid is weak, and if the curing agent exceeds 5.0 wt %, the role of other components may be reduced.
For example, the curing agent may include one of an epoxy-based resin and a phenol-based resin. In addition, epoxy resin may include at least one of bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, bisphenol epoxy resin, phenolic novolac epoxy resin, cresol novolac epoxy resin, bisphenol A novolac epoxy resin, bisphenol F novolac epoxy resin, phenolic salicylic aldehyde novolac epoxy resin, cycloaliphatic epoxy resin, aliphatic chain epoxy resin, glycidyl ester type epoxy resin, and modified resins thereof.
In addition, the phenolic resin may include at least one of bisphenol F, bisphenol A, bisphenol S, polyvinyl phenol, phenol, cresol, alkyl phenol, catechol, novolac resin, and halide substitutes thereof.
If manufacturing a negative electrode, the electrode mixture M input into the injection device 10 may be configured to form a negative electrode. The electrode mixture M of the negative electrode may include a negative electrode active material, a binder, a conductive material, and a curing agent. In addition, the electrode mixture M of the negative electrode may include, based on 100 wt % of the electrode mixture, 85.0 wt % to 98.5 wt % a negative electrode active material, 0.5 wt % to 5.0 wt % of a binder, 0.5 wt % to 5.0 wt % of a conductive material, and 0.5 wt % to 5.0 wt % of a curing agent. Since the effects of the binder, conductive material, and curing agent on the negative electrode active material are the same as those on the positive electrode active material on the positive electrode, detailed description is omitted.
In the first step ST1, a rectangular space may be formed with an upper mold 21 and a lower mold 22 of the injection mold 20, and the electrode sheet S1 may be molded into a plate-shaped rectangular parallelepiped. In the first step ST1, the overall thickness of the electrode sheet S1 may be uniformly formed. In some embodiments, the temperature of the injection mold 20 may range from 100 to 230° C.
The injection device 10 may be configured to inject the electrode mixture M input into a hopper 11 into the interior of the injection mold 20 connected to a discharge port 13 by rotating a screw 12. A heater 14 may be provided on the outside of the screw 12 and the discharge port to facilitate the injection of the electrode mixture M.
The injection mold 20 may include the upper mold 21 and the lower mold 22 for molding the electrode sheet S1. The upper mold 21 may include a plate-forming region 211 formed by rectangular parallelepiped engraving to correspond to the shape of a plate, and an injection hole 212 for injecting the electrode mixture M into the interior of the injection mold 20. The injection holes 212 may be provided in a plurality of line types so that the electrode mixture M may be uniformly and quickly injected into the interior of the injection mold 20. The lower mold 22 may be formed with a plate-forming region 221 formed by rectangular parallelepiped engraving to correspond to the shape of a plate. The inner surface of the lower mold 22 may have a rectangular shape.
In the third step ST3, the metal substrate S2 is cut. In the third step ST3, the electrode sheet S1 may be laminated by heat-pressure P on one surface of the metal substrate S2, and the electrode sheet S1 is laminated by the heat-pressure P on the other surface of the metal substrate S2, in a press device 30. The electrode sheet S1 may be laminated on both surfaces of the metal substrate S2 by two heat-pressure laminating processes. Thus, the electrode 40 of the rechargeable battery may be completed.
Referring to
In this way, by producing the electrode sheet S1 with the injection mold 20, the loss of the electrode mixture, i.e., the active material, is not generated, wrinkles are prevented from occurring on the uncoated region of the metal substrate S2, and the loss of the metal substrate S2 due to edge slitting may be minimized.
It is possible to injection mold a different electrode sheet S1 by replacing the injection mold 20, thereby reducing material loss and time loss when converting electrode specifications.
The injection mold 20 molds the thickness of the electrode sheet S1 to be thicker than the thickness of the conventional active material layer and is made of a rectangular parallelepiped plate, so that if embedding the electrode assembly in a pouch, the rounding of the pouch is minimized to enable high-capacity design. The plate rectangular electrode sheet S1 facilitates management of the negative-positive ratio (N/P ratio).
Hereinafter, various embodiments of the present disclosure will be described. Descriptions of the same configurations as the first embodiment and the previously described embodiments will be omitted, and descriptions of different configurations will be described.
Referring to
In the first step ST1′, a chamfer S11 may be molded, in which the thickness may become gradually thinner on the outer portion of one surface of an electrode sheet S1′, by the convex round region 622 at the corner of the lower mold 62 of the injection mold 60. The chamfer S11 may further prevent defects from occurring at the corners of the electrode sheet S1′.
The unwinding reel R1 may supply the metal substrate S2″, and the rewinding reel R2 may rewind the electrode sheet S1 laminated on both surfaces of the metal substrate S2″. The metal substrate S2″ enables a continuous process, which may implement the efficiency of the process of laminating the electrode sheet S1, and allow forming a jelly roll-type electrode assembly with the electrode sheet S1 laminated.
Embodiments of the present disclosure provide a manufacturing method of an electrode for a rechargeable battery, capable of eliminating and reducing the loss and defect rate of electrode mixtures (including active materials) and metal substrates.
According to the embodiments, the injection mold may be manufactured in the shape of the electrode sheet to reduce the loss of the electrode mixture containing the active material, and the molded electrode sheet may be laminated with a metal substrate to prevent defects caused by wrinkling of the uncoated region and to minimize the loss of metal substrate caused by slitting of the edge.
According to the embodiments, it is possible to injection mold a different electrode sheet by replacing the injection mold, thereby reducing material loss and time loss when converting electrode specifications. In addition, according to the embodiments, the thickness of the electrode sheet may be molded to be thicker than the conventional method and implemented in a more right-angled shape, thereby enabling high-capacity design of the rechargeable battery and advantageous management of the negative-positive ratio (N/P ratio). In this way, the quality of electrodes in secondary batteries may be improved.
While this disclosure has been described in connection with what is presently considered to be practical embodiments, it is to be understood that the disclosure is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.
Example embodiments have been disclosed herein, and although specific terms are employed, they are used and are to be interpreted in a generic and descriptive sense only and not for purpose of limitation. In some instances, as would be apparent to one of ordinary skill in the art as of the filing of the present application, features, characteristics, and/or elements described in connection with a particular embodiment may be used singly or in combination with features, characteristics, and/or elements described in connection with other embodiments unless otherwise specifically indicated. Accordingly, it will be understood by those of skill in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as set forth in the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2023-0107763 | Aug 2023 | KR | national |
