Method for converting metal foil web material into electrode web

Abstract

A method for processing a metal foil web material into an electrode web, the method comprising the steps of: operating a die coater to coat an active material layer on the metal foil web material; supplying a first portion of the metal foil web material from a first supply roll to the die coater; providing a second supply roll for carrying a second portion of the metal foil web material; providing adhesive to a leading end portion of the second portion of the metal foil web material; adhering the leading end portion of the second portion of the metal foil web material to a section of the first portion of the metal foil web material so that the adhesive is interposed between the first and second portions of the metal foil web material; and cutting the first portion of the metal foil web material from the first supply roll at or behind the adhesive.

Description

[Technical Field]

[0001] The present invention relates to a method for converting a metal foil web material into an electrode web and a machine for carrying out said method. [Background technology]

[0002] In modern society, the development of battery technology has become extremely important as portable devices such as mobile phones, laptops, camcorders, and digital cameras have become more commonplace. Furthermore, rechargeable / dischargeable secondary batteries have become an essential power source for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs), which address issues such as air pollution and carbon dioxide emissions caused by existing fossil fuel-powered internal combustion engine vehicles. Therefore, there is a growing need for improvements in secondary batteries.

[0003] Currently commercially available secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, and lithium secondary batteries. Of these, lithium secondary batteries are attracting attention due to their various advantages, such as almost no memory effect compared to nickel-based secondary batteries, the ability to charge and discharge freely, a very low self-discharge rate, and high energy density.

[0004] Secondary batteries can be classified into cylindrical batteries in which an electrode assembly is mounted in a cylindrical metal can, prismatic batteries in which an electrode assembly is mounted in a prismatic metal can, and pouch batteries depending on the shape of the battery case. Pouch-type secondary batteries generally contain an electrode assembly, in which electrodes and separators are alternately arranged, housed in a pouch-shaped case made of laminated aluminum sheets.

[0005] Secondary batteries can also be classified by their stacked structure, with a separator interposed between the negative and positive electrodes. Examples include a laminated structure, in which multiple negative and positive electrodes cut to a predetermined unit size are stacked sequentially with a separator interposed between them. Recently, to solve the problems associated with jelly-roll and stacked electrode assemblies, stacked / folded electrode assemblies, which combine the jelly-roll and stacked electrode assemblies, have been developed. Such stacked electrode assemblies are also called electrode stack assemblies.

[0006] Electrodes, i.e., negative and positive electrodes, are typically formed by coating a metal foil web stock with a layer of active material and then separating individual electrodes from the coated metal foil web. The web stock is typically supplied to the processing assembly in the form of a supply roll. To maximize output, it is desirable to minimize downtime of the processing assembly and ensure that the produced electrodes meet quality standards and minimize rejects. To achieve this, it is desirable to switch from one supply roll to the next as efficiently as possible.

[0007] Korean Patent Application Publication No. KR 10-2023-0004997 A1 discloses a method for connecting electrode sheets by attaching a web material portion of a first supply roll to a downstream portion of a second supply roll, and this method is performed by aligning the edge of the first portion with the edge of the second portion and attaching tape to the adjoining surfaces.

[0008] Other methods for attaching electrode foils are described in Korean Patent No. KR 10-1269482 B1, US Patent Application Publication No. US 2012 318 462 A1, or Japanese Patent Application Publication No. JP 1997 0219 189 A2.

[0009] Typical methods of switching from a first supply roll to a second supply roll in an assembly for converting metal foil web material into an electrode web result in significant downtime between the processing of the first portion of the web material and the downstream processing of the second portion. Additionally, attaching the leading edge portion to the downstream portion often reduces the quality of the coating downstream of the joint, and the substandard material cannot be used in battery manufacturing and must be discarded.

[0010] Additionally, existing methods can result in sticky adhesive residue building up on deflection pulleys, tensioning rollers, and the like, which can cause damage to the web material being processed, require tedious cleanup and downtime, and reduce manufacturing efficiency. Summary of the Invention [Problem to be solved by the invention]

[0011] The object of the present invention is to overcome the shortcomings of the prior art and in particular to provide an improved method for converting metal foil web material into an electrode web that allows for rapid, reliable and / or efficient production of the highest quality. [Means for solving the problem]

[0012] One or more problems known in the prior art are solved by the subject matter of the independent claims. Particular embodiments are presented by the features of the dependent claims.

[0013] This provides a method for converting a metal foil web material into an electrode web. The electrode web can be further processed for use as an electrode plate, particularly a positive or negative electrode plate. In particular, the electrode plate produced by the method for converting a metal foil web material into an electrode web described below can be formed into a jellyroll-type electrode assembly, a stacked electrode assembly, or a stacked / folded electrode assembly. The method for converting a metal foil web material includes several steps.

[0014] A method for processing a metal foil web material includes operating a die coater to coat an active material layer on the metal foil web material. While processing the metal foil web material, the die coater can operate continuously and / or constantly to coat the active material layer on the metal foil web material. The method for processing a metal foil web material can include several steps of operating one or more die coaters to coat an active material layer on a first surface and / or a second surface of the metal foil web material. The method for processing a metal foil web material may preferably include a first step of operating a first die coater to coat a first active material layer on a first surface of the metal foil web material and a second step of operating a second die coater to coat a second active material layer on a second surface of the metal foil web material. In this case, the first active material layer and the second active material layer preferably contain or are composed of the same components. The first and second coating steps can be performed consecutively. One or more drying steps can be performed immediately after each coating step to dry and cure the active material layer. In particular, a first drying step can be carried out after the first coating step, in particular before a subsequent second coating step. A second drying step can be carried out after the second coating step.

[0015] The method for converting metal foil web material also includes providing a first portion of the metal foil web material from a first supply roll to a die coater and a second supply roll carrying a second portion of the metal foil web material. As the metal foil web material is fed from the supply roll to the die coater, it may travel along one or more intermediate components or parts, including pulleys, particularly one or more deflection pulleys and / or tension rollers.

[0016] The term "web material" should be understood as a general term referring to web-like materials such as films, sheets, foils, nets, and porous materials (e.g., sieves, foams, nonwoven fabrics). The web material has a web length dimension significantly greater than its web width dimension, which in turn is significantly greater than its web thickness dimension. For example, the web thickness dimension of the metal foil web material to be processed can be in the range of 1 μm to 100 μm, preferably 3 μm to 30 μm, and more preferably 5 μm to 15 μm. For example, the web width dimension of the metal foil web material to be processed can be in the range of 1 mm to 5000 mm, preferably 10 mm to 1000 mm, and more preferably 50 mm to 500 mm. For example, the web length dimension of the metal foil web material to be processed can be in the range of 10 m to 100 km, preferably 100 m to 50 km, and more preferably 500 m to 25 km. Typical web material travel speeds during processing, particularly during the coating step, can be as high as 100 m / min. When newly loaded onto the supply rolls, the web length may preferably be wound onto each supply roll. The supply from the supply roll to the die coater can preferably move along the longitudinal direction of the web. The rotation axis of the supply roll is preferably arranged parallel to the web width direction. The radial direction of the supply roll preferably corresponds to the web thickness direction. The first supply roll and the second supply roll preferably carry the same type of metal foil web material. Preferably, the supply rolls carry metal foil web material of the same thickness dimension and / or the same width dimension. Although not required, it may be preferable to carry metal foil web material of the same or at least similar web length dimension, at least initially, before the supply roll is unwound.

[0017] The method also includes providing adhesive to a leading edge of the second portion of the metal foil web material. The leading edge of the metal foil web material includes its leading edge and a portion of the web material behind the leading edge. The adhesive can be positioned a certain distance from the leading edge of the second portion or the leading edge of the leading edge of the leading portion. The adhesive can be provided in a second portion of the adhesive region that extends in the width and length directions of the second portion. The adhesive region preferably extends continuously from the first (left) side edge to the second (right) side edge. The adhesive region can have a longitudinal extension dimension that is equal to or less than the extension dimension of the metal foil web material and / or the widthwise adhesive region. The adhesive can be provided in the second portion as a layer that extends continuously across the entire width of the metal foil web material. Alternatively, the adhesive can be provided in the second portion, preferably in a regular pattern, such as a pattern including multiple dots, lines, etc. Preferably, the distance between the adhesive and the leading edge in the longitudinal direction of the web can be less than 1 m, particularly less than 10 cm or less than 1 cm. The step of providing adhesive to the leading edge of the second portion of the metal foil web can be performed before or while the second supply roll is provided. The adhesive can be provided to the leading edge of the second portion while the second portion is completely wound onto the second supply roll, before it is wound onto the supply roll, or after the second portion of the metal foil has begun to unwind from the second supply roll. For example, the adhesive can be provided to the second portion of the metal foil web material in liquid or solid form, such as a strip of tape. The adhesive provided to the leading edge of the second portion of the metal foil web material can include a solvent, particularly an aqueous or organic solvent.

[0018] The method also includes attaching a leading end of a second portion of the metal foil web material to a section of the first portion of the metal foil web material so that adhesive is interposed between the first and second portions of the metal foil web material. The first and second portions are preferably attached to each other so that their respective longitudinal directions are aligned. Alternatively or additionally, when the leading end of the second portion is attached to the first portion, the first (left) side edge and / or the second (right) side edge of the first and second portions may preferably be aligned. The adhesive may be provided in a first portion of the attachment region that extends in the width and length directions of the second portion. The attachment region may preferably extend continuously from the first (left) side edge to the second (right) side edge of the second portion. The attachment region may have a longitudinal extension that is no greater than the extension of the metal foil web material and / or the attachment region in the width direction. The leading end of the second portion is attached to the section of the first portion, thereby allowing the adhesive to adhere to the first and / or second portions. For example, the adhesive may include a liquid adhesive or adhesive tape that is applied to both the first and second portions. The adhesive area may be the same as or larger than the adhesive area.

[0019] The method for converting the metal foil web material into an electrode web also includes cutting a first portion of the metal foil web material from the first supply roll at the adhesive, particularly at the attachment region, or behind the adhesive, particularly downstream of the attachment region. The cutting step is preferably performed on only the first portion. In particular, the cutting step maintains the second portion of the metal foil web material intact.

[0020] The leading edge of the metal foil web material may be the radially outermost portion of the metal foil web material before it is unwound from the supply roll. The leading edge may generally represent the frontmost portion as the web material passes through the machine. As the second portion moves, the second portion follows the leading edge of the metal foil web material as it passes through the converting machine. In particular, the leading edge of the leading edge is the first portion of the second portion of the metal foil material that contacts a component or part of the machine that processes the metal foil web during the method, before other portions of the second portion contact the component or part. When viewed in the processing direction of a machine configured to perform the method, the leading edge may be referred to as the leading end of the second portion of the metal foil web material. The leading edge forms a boundary of the leading edge. The entire second portion of the metal foil web material may follow behind the leading edge during the method. In particular, the machine includes a first die coater configured to coat a first active material layer on a first surface of the metal foil web material and a second die coater configured to coat a second active material layer on a second surface of the metal foil web material.

[0021] Advantageously, the above method allows for achieving a particularly strong bond between portions of metal foil web material being coated in a die coater. This method allows for the second portion to be rapidly attached to the first portion to minimize downtime during conversion from one supply to another. By attaching the first and second portions via an adhesive disposed between the portions of web material, the amount of adhesive that can contaminate assembly components such as deflection pulleys, tension rollers, etc. is significantly reduced.

[0022] As the first supply roll nears the end of its supply, a changeover to the second supply roll of metal foil web material can be performed as described herein, thereby enabling the second supply roll to become the (new) first supply roll. During or after the changeover from the first supply roll to the second supply roll, the first supply roll can be discarded, and the second supply roll can be placed in the position of the (current: previous) first supply roll. For example, the second supply roll can move along its rotational path to the position of the (previous) first supply roll and act as the (new) first supply roll, particularly until the metal foil web material on the (previous: second) supply roll is nearly completely unwound. The second supply roll can be rotated to a supply position where it can be placed before or during further application of the second portion of the web material to the first portion, and to an operating position where it can be maintained during the majority of the process of coating the metal foil web material with the active material and / or during the changeover of the supply roll.

[0023] A preferred embodiment of the method according to the present invention also includes providing an adhesive comprising a first section near the leading edge of the first portion of the metal foil web material and a second section far from the leading edge. Preferably, the cut can be performed in the adhesive and / or bonding area defined by the second section. Alternatively, the cut can be performed downstream with respect to the second section, near the second section, or at the downstream end of the second section. The adhesive can have different properties in the second section compared to the first section, particularly with respect to adhesion to the first portion. The cut is performed in the second section. Preferably, the cut can be performed so that the first portion of the metal foil web material has a trailing edge that is partially, or preferably completely, disposed within the second section. In particular, the adhesive is provided so that the second section is behind the first section. It may be preferable to provide the adhesive in the first section near or at the leading edge and the second section of adhesive downstream from the leading edge. The first section has a first length in the longitudinal direction of the web material, and the second section has a second length. The first length can be substantially the same as or the same as the second length. In particular, the second length may be longer than the first length. Alternatively, the first length may be longer than the second length. In some embodiments, the second section is longer than the first section. In particular, the length of the second section is equal to or less than the width of the metal foil web material.

[0024] In a further preferred development, a gap is provided separating the first and second sections. This gap preferably represents an adhesive-free area of ​​the first and / or second portions of the metal foil web material. The gap can be provided in the second portion so as to extend in the width and length directions of the second portion. It may be preferable to provide the gap by providing adhesive at the leading edge of the second portion of the metal foil web material, such that the adhesive of the first section is provided immediately adjacent to or at the leading edge, and the second section of adhesive is provided downstream of the leading edge at a distance from the first section that defines the gap. The gap preferably extends continuously from the first (left) side edge to the second (right) side edge of the first and / or second portion. The gap can have a longitudinal extension not greater than the widthwise extension of the metal foil web material. In particular, the gap can extend in the longitudinal direction of the web material to a gap length as long as the first section and / or as long as the second section. Alternatively, the gap can extend in the longitudinal direction of the web material to a gap length equal to or shorter than the gap length of the first section and / or the second section. The gap length may be shorter than both the first and second sections. It may be preferred that the gap extends in the longitudinal direction of the web material a gap length at least as long as the first section and not longer than the second section. The gap may be provided between the first and second sections so as to extend continuously across the entire width of the metal foil web material.

[0025] In another further development that can be combined with the above-described embodiment, the adhesive strength provided to secure the first portion is weaker in the second section than in the first section. The adhesive strength in the first section may be particularly greater than the adhesive strength in the second section, preferably at least twice as great, or preferably at least ten times greater. It may be preferable for the adhesive strength attaching the leading end of the second portion of the metal foil web material, through which most of the tensile forces are transmitted, to the first portion of the metal foil web material to be particularly strong. It may be preferable for the adhesive strength attaching the trailing end or "tail" of the first portion of the metal foil web material to be relatively weak, in order to secure the second portion of the metal foil web material without flapping. The adhesive strength in the first section is preferably substantially stronger than the adhesive strength in the second section. The adhesive strength provided by the adhesive may be in the range of 5 gf / 25 mm to 2000 gf / 25 mm, preferably in the range of 10 gf / 25 mm to 1000 gf / 25 mm. The adhesive strength of the first section can be 750 gf / 25 mm or more, particularly 850 gf / 25 mm or more, and preferably 1000 gf / 25 mm or more. The adhesive strength of the second section can be 200 gf / 25 mm or less, particularly 100 gf / 25 mm or less, and preferably 50 gf / 25 mm or less. In a particularly preferred embodiment, the adhesive strength of the second section can be 20 gf / 25 mm or less, and the adhesive points of the first section can be at least 900 gf / 25 mm. Providing adhesive can include providing a first adhesive means (e.g., a first double-sided adhesive tape) to the first section and a second adhesive means (e.g., a second double-sided adhesive tape) to the second section. Providing a relatively weak adhesive force to the second section can minimize contamination of deflection pulleys, tension rollers, etc., due to excess adhesive exposed at or behind the trailing edge of the first section. Adhesion strength can be determined in accordance with EN 1939:2003 or ASTM D3330.

[0026] According to some embodiments, the adhesive is provided as a double-sided tape. In such embodiments, where the adhesive includes distinct sections with different adhesive properties, a first double-sided tape can be provided in the first section and a second double-sided tape can be provided in the second section. The double-sided tape can include a first adhesive layer for adhering to a first portion of the metal foil web material and a second adhesive layer for adhering to a second portion of the metal foil web material. The double-sided tape can also include a substrate layer interposed between the first adhesive layer and the second adhesive layer. The adhesive properties of the first and second adhesive layers of the double-sided tape can be the same or different. In particular, the adhesive properties of the first and second adhesive layers of the double-sided tape provided in the first section can be the same. Alternatively or additionally, the adhesive properties of the first and second adhesive layers of the double-sided tape provided in the second section can be different, and in particular, the adhesive strength of the second adhesive layer can be less than the adhesive strength of the first adhesive layer, preferably less than half, more preferably less than one-tenth. The use of double-sided tape as adhesive has been shown to be advantageous in that the tape can be applied in a very simple and precise manner, and since the position and amount of adhesive is well defined, it can be advantageous to use adhesive tape to prevent contamination of deflection pulleys, tension rollers, etc.

[0027] The adhesive can be provided on the second portion so as to have a thickness smaller than the width of the die coater slot through which the metal foil web material passes. It may be preferable to select an adhesive, particularly a double-sided tape, so that the thickness of the composite metal foil web material in the attachment / bonding region where the first and second portions of the metal foil web material overlap is smaller than the width of the die coater slot through which the metal foil web material passes during coating of the metal foil web material. It may be preferable that the thickness of the composite metal foil material including the adhesive interposed between the first and second portions of the metal foil web material is smaller than the active material layer coated on one side of the metal foil web material in the coater operating step.

[0028] In some embodiments, the cutting step and the step of attaching the leading end of the second portion to the first portion are performed using a combined stamping and cutting tool. The cutting and attaching steps can be performed simultaneously. The combined tool can be used to press the first portion against the second portion with adhesive disposed therebetween and cut the second portion at the attached area. The combined tool can include a cutting tool configured to join the first portion of the metal foil web material and a stamping tool that presses the first portion against the adhesive disposed on the second portion. Performing the operations using a combined tool to accomplish the attaching and cutting steps allows for particularly rapid and reliable processing of the metal foil web material. The combined tool can be used to cleanly and precisely cut the second portion depending on the desired relationship to the adhesive, particularly the attached area.

[0029] In some embodiments, the coater is operated to continuously coat the metal foil web material with active material. In particular, the coater is operated to continuously coat the metal foil web material with active material as the metal foil web material passes through the coater. In particular, the coater can be operated continuously while the supply of metal foil web material is diverted from a first supply roll to a second supply roll. Preferably, the coater is operated continuously downstream of a point in the processing assembly where a leading end of a second portion of the metal foil web material is attached to a section of the first portion of the metal foil web material. The coater can be operated upstream of a device, such as an oven, for fixing the newly applied active material coating to the metal foil web material. The method can include operating multiple die coaters to coat the metal foil web material with an active material layer, where a first die coater is operated to coat a first side of the web material and a second coater is operated to coat a second side opposite the first side of the web material. The multiple die coaters can be operated continuously and simultaneously to coat the web material with an active material layer.

[0030] The first die coater is operable to coat a first surface of the metal foil web material, preferably the surface of the metal foil web material where the trailing end of the first portion formed by cutting is located, and is positioned downstream of the location where the second portion is attached to the first portion. The first device (e.g., a first oven) is operable to fix the first active material layer to the metal foil web material and is positioned downstream of the first die coater, preferably immediately downstream of the first die coater. The first oven or similar device is preferably positioned between the first and second die coaters in the direction of movement of the metal foil web material.

[0031] The second die coater is operable to coat a second side of the metal foil web material, preferably the side of the metal foil web material where the leading end of the second portion is located, and is positioned downstream of the location where the second portion is attached to the first portion. The second apparatus (e.g., a second oven) is operable to fix a second active material layer to the metal foil web material and is positioned downstream of the second die coater, preferably immediately downstream of the second die coater.

[0032] It may be preferred that the second side of the metal foil web material is coated with the active material after the first side of the metal foil web material is coated with the active material. The second die coater can be located downstream of the first die coater.

[0033] In some embodiments, the active material is coated onto the adhesive, particularly directly onto the adhesive on the first side of the metal foil web material (where the trailing edge of the first portion formed by cutting is located). The second portion can be cut so that the trailing edge of the second portion is formed over the adhesive area. By coating the active material layer onto the adhesive, particularly on the first side of the metal foil and / or particularly directly onto the adhesive, particularly on the second section of adhesive that secures the trailing edge of the first portion, the trailing edge is securely secured between the adhesive and the active material. To achieve a particularly clean and reliable bond, it may be preferable to subsequently coat the side opposite the leading edge of the second portion, where the leading edge is securely attached to the second portion. By providing the active material coating immediately on the adhesive after cutting the first portion and thereby exposing the adhesive, contamination of assembly components downstream of the first die coater, particularly deflection pulleys, tension rollers, etc., can be minimized or even prevented.

[0034] In some embodiments, the first and second supply rolls supply the same metal foil web material. In particular, the metal foil web material supplied by the first and second supply rolls is provided to comprise a copper alloy. Alternatively or additionally, the metal foil web material supplied by the first and second supply rolls is provided to comprise an aluminum alloy. Alternatively, the metal foil web material supplied by the first and second supply rolls is provided to be composed of an aluminum alloy or a copper alloy.

[0035] According to some embodiments, the cutting step is performed along a cutting line across the first portion, in particular at an angle of 60° to 120°, preferably 80° to 100°, relative to the direction of movement of the metal foil web material. More particularly, the cutting line may pass through the first portion perpendicularly or nearly perpendicularly to the direction of movement of the metal foil web material.

[0036] In particular, the cutting step can form a serrated edge along the trailing edge of the first portion. The serrations can be formed in a pattern with an angle, particularly an acute angle, pointing downstream. Forming a serrated edge along the trailing edge of the first portion can prevent tearing of the foil or active material layer and improve the transition from the first portion.

[0037] In some embodiments, adhesive is provided on a surface of the second portion of the metal foil web material facing radially outward on the second supply roll. The adhesive can be provided on the outer peripheral surface of the second supply roll before or after the roll is provided to the processing assembly. The adhesive is provided on the second roll before the second roll is attached to the first portion. The adhesive is preferably provided on the outer surface of the second roll. The adhesive is preferably provided on the second roll before the metal foil web material is unwound from the second supply roll.

[0038] In some embodiments, the adhesive is applied to a radially inward facing side of the first portion of the metal foil web material on the first supply roll. Alternatively, the adhesive can be applied to a radially outward facing side of the first portion of the metal foil web material on the first supply roll. The adhesive can preferably be applied after the first portion of the metal foil web material is unwound from the first supply roll. Preferably, the adhesive is applied to a section of the first portion of the metal foil web material closer to the trailing end than the leading end of the first portion attached to the first supply roll. The adhesive can be applied to a section of the first portion of the metal foil web material less than 1 km, preferably less than 500 m, more preferably less than 250 m or less than 100 m from the trailing end of the second portion attached to the first supply roll. The adhesive and the second portion of web material are preferably applied to the section of the first portion of web material just before the first supply roll is emptied.

[0039] In a preferred embodiment of the present invention, after coating the metal foil web material with an active material layer, a portion of the electrode web containing the adhesive is separated from the portion of the electrode web designated for use as an electrode, and that portion contains the adhesive and up to 15,000 mm, particularly up to 1,500 mm, of metal foil web material following the adhesive, and that portion is designated for discard. Disturbances in the coating caused by switching from the first supply roll to the second supply roll are minimized, and only material affected by the area where the adhesive is applied and a short distance downstream is removed, thereby minimizing the length of the discarded web. Using the methods described herein, waste of metal foil web material coated with an active material layer can be minimized, resulting in a more efficient manufacturing process.

[0040] The present invention also relates to a machine configured to convert a metal foil web material into an electrode web according to the above-described method. The machine may include at least one first support for a first supply (particularly a first supply roll) of metal foil web material and a second support for a second supply (particularly a second supply roll) of metal foil web material. The machine may include a device configured to provide adhesive, particularly at the leading end of a second portion of the metal foil web material, particularly at the location of the second supply of electrode web material, preferably on the second supply roll. The machine may include a device configured to attach the first portion of the metal foil web material to the second portion of the metal foil web material. The machine may also include a cutting device configured to cut an end of the first portion of the metal foil web material to form a trailing edge of the first portion. The machine may preferably include a combined cutting and attaching device. The combined cutting / attaching tool may include a common driver, such as an electric motor or piston actuator, for providing a cutting force for cutting the first portion to form the trailing edge and an attaching force for compressing the first and second portions of the metal foil web material against the adhesive on opposite sides. Additionally, the machine may include winding means and / or drive means configured to drive the metal foil web material. The machine may include a number of components such as deflection pulleys, tension rollers, etc.

[0041] A battery generally includes two electrodes of opposite polarity, a negative electrode and a positive electrode. The electrodes are placed in a mutual container with a separator membrane. The separator membrane divides the container so that the negative and positive electrodes do not come into direct contact with each other to avoid short circuits. The mutual container is filled with an electrolyte solution that allows ions to pass from the positive electrode to the negative electrode, resulting in a chemical reaction that releases electrical energy. Each electrode of a battery can include a corresponding foil. This foil can include or be made of an electrically conductive material. In particular, this foil can be made of or include a metal or metal alloy, including or consisting of aluminum or copper. It may be preferable for at least one electrode of a battery to be realized as a foil coated with an active electrode material (abbreviated as active material).

[0042] For example, an electrode configured to function as a negative electrode can be provided with an active material layer configured to accommodate and / or store, preferably reversibly store, ions. In particular, the active material for a negative electrode can include graphite as a primary component. An electrode configured to function as a positive electrode can include an active material configured to release ions. In particular, the active material for a positive electrode can include or consist of a metal oxide, such as lithium oxide. The active material can include or consist of, for example, LCO (LiCoO), NCM (Li(NiCoMn)O), NCA (Li(NiCoAl)O), LMO (LiMnO), and / or LFP (LiFePO). The active material can include conductive additives, binders, fillers, and other components (active material mixture). The positive electrode active material can be configured to be rechargeable. The process of releasing ions from the positive electrode active material and receiving ions by the negative electrode active material can be referred to as discharging. The process of releasing ions from the negative electrode active material and recharging the positive electrode active material with ions can generally be referred to as charging or recharging. The active materials used in the electrodes of a battery are considered essential in determining the battery's characteristics, such as capacity, voltage, and memory effect.

[0043] In the present invention, the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate may include, without limitation, all active materials known in the technical field related to the present invention.

[0044] For example, the positive electrode active material is A [A x M y ]O 2+z and alkali metal compounds represented by the formula (wherein A comprises at least one of Li, Na, or K; M comprises at least one selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru, and Cr; x≧0, 1≦x+y≦2, 0.1≦z≦2; the stoichiometric coefficients x, y, and z are selected to maintain electrical neutrality of the compound).

[0045] In other examples, the positive electrode active material is xLiM 1 O2(1-x)Li2M 2 O3 alkali metal compound (M 1 contains at least one element having an average trivalent oxidation state; M 2 contains at least one element having an average tetravalent oxidation state; 0≦x≦1).

[0046] In another example, the positive electrode active material is Li a M 1 x Fe 1-x M 2 y P 1-y M 3 z O 4-z It may be a lithium metal phosphate represented by the formula (M 1 contains at least one selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg and Al; M 2 contains at least one selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, Al, As, Sb, Si, Ge, V, and S; M 3 contains a halogen group element optionally containing F; 0<a≦2, 0≦x≦1, 0≦y<1, 0≦z<1; the stoichiometric coefficients a, x, y and z are selected so that the compound maintains electrical neutrality), or Li3M2(PO4)3 [M contains at least one selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg and Al] may be used.

[0047] Preferably, the positive electrode active material can include primary particles and / or secondary particles formed by aggregation of the primary particles.

[0048] For example, the negative electrode active material can include a carbon material, lithium metal or a lithium metal compound, silicon or a silicon compound, and tin or a tin compound. Metal oxides having a potential of less than 2 V, such as TiO2 and SnO2, can be used as the negative electrode active material. The carbon material can include low-crystalline carbon and high-crystalline carbon.

[0049] However, the problems to be solved by the embodiments of the present invention are not limited to the above problems, and can be variously expanded within the scope of the technical ideas included in the present invention. [Effects of the Invention]

[0050] This embodiment can make the changeover from a first supply to a second supply more reliable in machines and processes for manufacturing electrode plates in a web-like manner. This embodiment can reduce the likelihood and severity of defects around the adhesive that attaches the leading first portion to the trailing second portion. This embodiment can make the changeover from a first supply to a second supply more rapid. This embodiment can allow the manufacturing process to operate continuously without the need for a pause to switch from one supply to the other. This embodiment can make the changeover from a first supply to a second supply more efficient in machines and processes for manufacturing electrode plates in a web-like manner. This embodiment can reduce or eliminate the need to clean adhesive from machine components.

[0051] The effects of the present invention are not limited to those described above, and additional effects not described herein will be clearly understood by those skilled in the art from the description of the accompanying claims. [Brief explanation of the drawings]

[0052] [Figure 1] This machine implements the method of converting metal foil web material into electrode webs. [Figure 2] FIG. 2 is a detailed view of a composite tool in the machine of FIG. 1; [Figure 3] FIG. 3 is a schematic view of a second supply roll according to the first embodiment. [Figure 4] 4 is a schematic view of a metal foil web blank including a first portion and a second portion from a second supply roll according to FIG. 3. FIG. [Figure 5] FIG. 10 is a schematic view of a second supply roll according to a second embodiment. [Figure 6] 6 is a schematic view of a metal foil web blank including a first portion and a second portion from a second supply roll according to FIG. 5. FIG. [Figure 7] FIG. 10 is a schematic view of a second supply roll according to a third embodiment. [Figure 8] 8 is a schematic view of a metal foil web blank including a first portion and a second portion from a second supply roll according to FIG. 7. FIG. [Figure 9] 8 is another schematic view of the metal foil web blank including the first and second portions from the second supply roll according to FIG. 7. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0053] The present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can easily implement various embodiments of the present invention. The present invention can be modified in various other ways and is not limited to the embodiments described herein.

[0054] In order to clearly describe the present invention, parts that are not relevant to the description may be omitted, and the same reference numerals represent the same elements throughout the description.

[0055] Furthermore, the size and thickness of each element in the drawings are arbitrarily shown for the convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings. The thicknesses of layers and regions in the drawings are exaggerated for clarity. The thicknesses of some layers and regions in the drawings are exaggerated for the convenience of explanation.

[0056] Furthermore, when an element such as a layer, film, region, or plate is referred to as being "on" or "above" another element, it can be understood that it may be directly above the other element, or that intervening elements may be present. In contrast, when an element is referred to as being "directly above" another element, it means that no other intervening elements are present. Furthermore, the words "on" or "above" mean that an element is disposed above or below a reference portion, and do not necessarily mean that an element is disposed at the top end of the reference portion in the direction opposite to gravity. On the other hand, when an element is described as being "on" or "above" another portion, as well as when an element is described as being "below" or "below" another portion, it can be understood with reference to the above content.

[0057] Furthermore, throughout the description, when a part is referred to as "comprising" or "having" a particular element, this does not mean that other elements are excluded, and that other elements may also be included, unless otherwise specified. Unless otherwise specified throughout the specification, each element may be singular or plural.

[0058] Additionally, when an element is referred to as being "coupled," "coupled," or "linked" to another element, it should be understood that the element can be directly coupled or coupled to the other element, but there may be intervening elements between the elements, and the elements may be "coupled," "coupled," or "linked" to one another via other elements.

[0059] Throughout the specification, "A and / or B" means A or B, or both A and B, unless expressly stated otherwise, and "C-D" means C or greater and D or less, unless expressly stated otherwise.

[0060] Methods according to embodiments of the present invention will now be described with reference to exemplary machines for performing such methods and products of such methods.

[0061] For illustrative purposes, FIG. 1 shows a machine 100 configured to convert a metal foil web material 1 into an electrode web 2. The metal foil web material 1 typically has a thickness of only a few microns, a width of a few centimeters, and a length that can reach one or more kilometers. The metal foil web material 1 is provided on a supply roll 10 or 20 and transported through the machine 100 along a transport direction indicated by the arrow. Within the machine 100, the metal foil web material 1 moves along a number of deflection pulleys 110 and tension rollers 120. Some pulleys are actuated to apply a tensioning force to the metal foil web material 1, while others are free-wheeling. The tension roller 120 is configured to apply lateral pressure to the moving metal foil web material 1, allowing the travel path to be altered to accommodate minor discrepancies in travel speed or elasticity. The metal foil web material 1 passes through a die coater 130, which is configured and operative to apply an active material layer 3 to the metal foil web material to form the electrode web 2. An oven 140 for curing the active material layer 3 is provided downstream of the die coater 130, and the electrode web 2 is stabilized.

[0062] The schematic diagram of the machine 100 shown in FIG. 1 shows only one die coater 130 and a subsequent oven 140 for coating only the first side of the metal foil web material 1. To produce an electrode web in which active material layers are provided on both sides of the metal foil web material, the metal foil web material 1 may preferably subsequently pass through a second die coater and a subsequent second oven for coating the opposite second side (not shown). One or more separators (not shown) may be provided at or downstream of the oven for cutting individual sheets from the electrode web 2. The separators may be operable to produce individual electrode sheets for use in batteries. The one or more separators may be operable to cut substandard portions of the electrode web, such as portions of the metal foil web material 1 where adhesive 31 is present between the first and second portions 11 and 21.

[0063] Before the machine 100 exhausts the continuous supply of metal foil web material 1 supplied from the first supply roll 10, a second supply roll 20 is provided. The second supply roll 20 is provided with adhesive 31 and a leading end 22 of a portion 21 of metal foil web material 1 to be wound thereon. To switch the supply of metal foil web material 1 from the first supply roll 10 to the second supply roll 20, the adhesive 31 is applied to the first portion 11 of metal foil web material 1 emerging from the first supply roll 10, and the second portion 21 of metal foil web material 1 emerging from the second supply roll 20 is adhered thereto. After the second portion 21 is attached to the first portion 11, a cutting tool is used to cut the first portion 11 near the adhesive 31, forming a trailing end 19 of the first portion 11, with the leading end 22 of the second portion 21 being attached to a central section of the first portion 11 remote from the end of the first portion 11 connected to the core or the like of the first supply roll. The adhesive 31 helps to form a continuous metal foil web material 1 from the first portion 11 and the second portion 21, and this metal foil web material 1 is fed to a die coater 130 and processed into an electrode web 2.

[0064] It is preferable to maintain a continuous supply of the metal foil web material 1 to be processed into the electrode web 2. The continuous supply of the metal foil web material 1 to the die coater 130 and its downstream components must be uninterrupted. Therefore, supply changeover must be performed before the metal foil web material 1 on the first supply roll 10 is depleted. To avoid process interruptions, the second portion 21 coming from the new second supply roll 20 is attached to the first portion 11 while the first portion 11 is being fed from the first supply roll 10 to the die coater 130. The joint section of the continuous metal foil web material 1 includes both the first portion 11 and the second portion 21 of the metal foil web material 1. Because the joint section includes two layers of the metal foil web material 1 and the intermediate adhesive 31, it cannot be used as the basis for a high-quality electrode after being covered with the active material 3. To minimize the joint section, the first portion 11 is cut as soon as possible after the second portion 21 is attached, as close as possible to the adhesive 31, taking into account the need for reliable adhesion. In some embodiments, the trailing end 19 of the first portion 11 can be located downstream relative to the adhesive 31. However, it may be preferable for the trailing end 19 of the first portion 11 to be located in the adhesive region defined by the presence of the adhesive 31 on the second portion 21.

[0065] Due to the forces acting on the metal foil web material 1 while passing through the machine 100, and particularly when the first portion 11 is cut in the adhesive area covered with adhesive 31, some parts of the machine 100, such as the deflection pulley 110 and tension roller 120, may be exposed to the adhesive 31 and leave behind residue. If the adhesive residue causes the metal foil web material 1 to adhere to parts of the machine, this may damage the web material 1 and the machine, disrupting the production process. To avoid adhesive from adhering to machine components, attempts are made to reduce the number of machine parts between the die coater 130 and the supply rolls 10, 20.

[0066] Generally, it is preferred to operate the die coater 130 (in the case of a machine comprising multiple die coaters 130: the first die coater through which the web passes as it comes from the supply) to first coat the side of the metal foil web material 1 on which the trailing end 19 of the first portion 11 formed by cutting is located.

[0067] In some embodiments, the tail of the first portion 11 extends behind the attachment section and covers the adhesive 31. In the embodiment described below in connection with FIG. 3, the trailing end 19 is loosely connected (in a tail or flap manner) to the second portion 21 via the adhesive 31, which attaches the second portion 21 to the attachment section of the first portion 11 away from the trailing end 19 of the first portion 11. At times, it may be preferable to avoid the presence of such a tail-like portion of the first portion 11. A metal foil web material 1 having a tail-like trailing end 19 increases the risk of damage in the die coater 130, which may occur due to unintentional misalignment of the tail.

[0068] In some embodiments, particularly those in which the first portion 11 is cut to form the trailing edge 19 at the bonded region, the adhesive 31 provided on the second portion 21 of the metal foil web material 1 is provided to have a strong adhesive strength in the first section 33 and a weak adhesive strength in the second section 35. Such an embodiment is described below, for example, in relation to FIG. 7. In such embodiments in which the trailing edge 19 of the first portion 11 is formed at the bonded region, it may be preferable to form the trailing edge 19 within the second section 35 of the adhesive 31. Thus, the adhesive 31 provides a strong adhesive strength in the first section 33 to securely secure the first portion 11 and the second portion 21 together as the metal foil web material 1 is pulled through the machine 100, but the strong adhesive 31 is not exposed from the first portion 11.

[0069] The second section 35 follows the first section 33. In the second section 35, the adhesive strength of the adhesive 31 may be significantly weaker than in the first section 33. The weak adhesive strength in the second section 35 may be so small that it is not sufficient, in itself, to provide reliable adhesion of the first portion 11 and the second portion 21 when considering the pulling forces experienced by the metal foil web material 1 in the machine 100. The weak adhesive strength in the second section 35 may be configured to secure the trailing end 19 of the first portion 11 to the second portion 21. Adhesives with relatively weak adhesive strength have been found to leave little or no residue when exposed to machine parts, and the discovery of weak adhesive residue does not pose a noticeable risk to the process.

[0070] 2 shows a detailed view of the joining tool 30 used in the illustrated embodiment to press the first part 11 against the adhesive 31 of the second part 21 to cut the first part 11. Those skilled in the art will understand that instead of the shown joining tool 30, separate tools can be provided, for example, a first tool for stamping and a second tool for cutting. The use of the joining tool 30 is advantageous in that the synchronization of the attachment of the first part 11 to the second part 21 and the cutting of the rear end 19 of the first part 11 can be achieved in a particularly simple and reliable manner. By using a joining tool for stamping and cutting, the distance between the attachment point and the cutting point can be defined with a small tolerance.

[0071] The tool 30 includes a stamping portion configured to press the first portion 11 against the adhesive section of the second portion 21, which is covered with adhesive 31. The tool 30 is preferably configured to be movable over a distance that can be set depending on the diameter of the second supply roll 20, as shown in FIG. 2, so that the same tool 30 can be used regardless of whether the second supply roll 20 has a relatively small diameter or a relatively large diameter.

[0072] The cutter of the tool 30 is configured to cut the second portion 21 of the metal foil web material 1 at a position trailing behind the first section 21 of the adhesive area of ​​the second portion 21 to which the adhesive 31 has been applied by the stamp. The extension of the adhesive section in the direction of movement or longitudinal direction of the metal foil web material can be set according to the effective distance between the cutter of the bonding tool 30 and the stamp, or the adhesive 31 can be supplied with a longitudinal dimension sufficient to allow different effective cutting distances.

[0073] FIG. 3 is a schematic diagram of a second supply roll 20 according to the first embodiment, and FIG. 4 is a schematic diagram of a metal foil web material 1 including a first portion 11 and a second portion 21 from the second supply roll 20 according to FIG. 3. The (second) supply roll 20 transports the (second) portion 21 of the metal foil web material 1. The supply roll 20 is a roll on which the metal foil web material 1 is wound. The metal of the metal foil material 1 can be, for example, copper, a copper alloy, aluminum, or an aluminum alloy. The metal foil web material 1 has a predetermined web length. The thickness of the metal foil web material 1 in the radial direction and the width in the axial direction are preferably constant throughout the entire web length.

[0074] The tip 22 of the second portion 21 extends axially along a straight line parallel to the rotational axis of the roll 20. The adhesive 31 is supplied to the second portion 21 immediately adjacent to the tip 22. The adhesive region defined by the adhesive 31 disposed on the outer circumferential surface of the second supply roll 20 begins at the tip. The adhesive 31 extends across substantially the entire width of the metal foil web material 1. Only small border regions of the metal foil web material 1 at the side edges are left free of adhesive. The border regions may be 1 cm or less on one or both side edges, and may be 5 mm or less. The adhesive region forms a uniform layer on the metal foil web material 1. The adhesive 31 may include adjacent sections with different adhesive properties or may consist of a single section with consistent adhesive properties. The adhesive 31 covers the adhesive region of the second portion 21, with a length in the longitudinal direction of the web greater than the thickness of the adhesive, which may cover 1 cm or more.

[0075] Figure 4 shows a section of metal foil web material 1 formed by adhering second portion 21 provided from roll 20 described above in connection with Figure 3 to first portion 11 of metal foil web material 1. Adhesive 31 adhering first portion 11 and second portion 21 is disposed at the leading end of the second portion. A trailing edge 19 of the first portion is spaced from adhesive 31. Trailing edge 19 is formed along a straight line that is essentially perpendicular to the side edges of metal foil web material 1. A serrated edge 18 is formed on trailing edge 19.

[0076] FIG. 5 is a schematic diagram of the second supply roll 20 according to the first embodiment, and FIG. 6 is a schematic diagram of the metal foil web material 1 including the first portion 11 and the second portion 21 from the second supply roll 20 according to FIG. 5.

[0077] The embodiment of the second supply roll 20 shown in FIG. 5 differs from the above-described embodiment in the arrangement of the adhesive 31. The adhesive 31 is supplied to the second portion 21, a first section 33 near the leading end 22 of the second portion 21, and a second section 35 remote from the leading end 22. Optionally, a gap 37 can be provided between the first section 33 and the second section 35. The first section 33, the second section 35, and the optional gap 37 can extend transversely to the side edges of the metal foil web material 1, in particular perpendicularly along a straight path. The adhesive 31 can be applied to the second portion 21 a short distance longitudinally from the leading end 22. The leading end 22, the first section 33, the second section 35, and the optional gap 37 can be arranged parallel to the leading end 22.

[0078] In the example shown in Figure 6, the second portion 21 according to Figure 5 is connected to the first portion 11 of the metal foil web material 1. The adhesive 31 adhering the first portion 11 and the second portion 21 is arranged near the leading end of the second portion. The trailing end 19 of the first portion is arranged at a distance from the adhesive 31 and behind the second section 35 of adhesive. The trailing end 19 is formed along a straight line that is essentially perpendicular to the side edges of the metal foil web material 1. A serrated edge 18 is formed on the trailing end 19.

[0079] FIG. 7 is a schematic diagram of the second supply roll 20 according to the first embodiment, and FIGS. 8 and 9 are schematic diagrams of the metal foil web material 1 including the first portion 11 and the second portion 21 from the second supply roll 20 according to FIG. 7.

[0080] The embodiment of the second supply roll 20 shown in FIG. 7 differs from the above embodiment only in that the adhesive 31 is flush with the leading edge 22. The first and second sections 33, 35 of adhesive can have the same adhesive strength for attaching the first portion 11, or preferably, the first section 33 has a substantially stronger adhesive strength than the subsequent second section 35. As shown, the second section 35 and the first section 33 can be the same size or substantially the same size. Alternatively, the second section 35 can have a shorter longitudinal extension compared to the longitudinal extension of the first section 33. FIG. 8 shows the second section 35 having a longer longitudinal extension than the first section 33. The height of the adhesive 31 is preferably constant, and in particular in those embodiments including distinct sections 33, 35 of adhesive 31, both sections 33, 35 can have the same or substantially the same height in the thickness direction of the metal foil web material 1. The widths of the first section 33 and the second section 35 of adhesive 31 in the axial direction of the second supply roll 20 are substantially the same or exactly the same. The border areas laterally adjacent to the first section 33 and the second section 35 are preferably constant or substantially constant. The border areas laterally adjacent to the first section 33 and the second section 35 are preferably the same size or substantially the same size on both sides. In particular, the border areas can have a width of 1 cm or less, in particular 5 mm or less, preferably 1 mm or less.

[0081] FIG. 8 shows a detailed schematic cross-section of the metal foil web material 1 passing through the adhesive region. In the illustrated example, the adhesive 31 includes a double-sided adhesive tape. Specifically, the adhesive 31 includes a first section 33 including a first double-sided adhesive tape and a second section 35 including a second double-sided adhesive tape. The adhesive tape includes a substrate layer 47 or matrix layer. The adhesive tape also includes adhesive layers 41, 43 on each side of the substrate layer 47. The first adhesive layer 41 is configured to provide a first adhesive force for securing the first portion 11 of the metal foil web material 1. The second adhesive layer 43 is configured to provide a second adhesive force for securing the second portion 21 of the metal foil web material 1. The adhesive strengths of the first adhesive layer 41 and the second adhesive layer 43 of each adhesive tape may be the same or different. It may be preferable for the adhesive tape used in the first section 33 to exhibit the same adhesive or securing strength in both adhesive layers 41, 43. It may be preferable for the adhesive tape used in the second section 35 to exhibit greater adhesive or securing strength in the second adhesive layer 43 compared to the first adhesive layer 41. The first adhesive strength for securing the first portion 11 may be substantially greater in the first section 33 than in the second section 35. The strong adhesive strength in the first section 33 may be 1000 gf / 25 mm or more. The weak adhesive strength in the second section may be 50 gf / 25 mm or less.

[0082] The first portion 11 of the metal foil web material 1 completely covers the first section 33. The second section is only partially covered by the first portion 11. A portion of the second section 35 of the adhesive 31 is exposed by the first portion 11. The first portion 11 can be sized to partially expose the adhesive 31 in the second section 35 behind the trailing end 19. Additionally, the first portion 11 can be sized to partially expose the adhesive 31 in the second section 35 behind the serrated edge 18 of the first portion 11. The gap 37 can be completely covered by the first portion 11. If the first portion 11 has a serrated edge 18, a portion of the gap 37 can be exposed. The thickness of the adhesive 31 can be greater than the thickness of the metal foil in one or both of the first portion 11 and the second portion 21.

[0083] FIG. 9 shows a schematic diagram of a metal foil web material 1 with a first portion 11 and a second portion 21 firmly attached to one another, in accordance with the description associated with FIG. 8. A first section 33 of adhesive 31 adheres the first and second portions together using a high adhesive force. The first portion 11 completely covers the first section 33 and the gap 37. The second section 35 is partially covered and partially exposed by the first portion 11, with the trailing end 19 having a serrated edge 18 located in the bonding area of ​​the second section 35 of adhesive 31 applied to the second portion 21.

[0084] Markers 51 may be located along one or both side edges of the metal foil web material 1. The markers may be provided at regular intervals, for example every 1000 mm. It may be preferable to locate such markers at the tip 22 and / or first section 33 of the second portion 21. Such markers may be useful for identifying the location of the adhesive 31, particularly after both sides of the metal foil web material 1 have been covered with active material 3 to form the electrode web 2.

[0085] Before being attached to the first part 11, the adhesive tape may be covered with a release film.

[0086] Although the preferred embodiments of the present invention have been described in detail as above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art by using the basic concept of the present invention defined in the appended claims are also included in the scope of the present invention. [Explanation of symbols]

[0087] 1: Metal foil web material 2: Electrode web 3: Active material layer 10: First supply roll 11: First part 18: Serrated edge 19: Rear end portion 20: Second supply roll 21: Second part 22: Tip part 30: Joining tool 31: Adhesive 33: First Section 35: Second Section 37: Gap 41: First adhesive layer 43: Second adhesive layer 47: Base material layer 51: Marker 100: Machine 110: Deflection pulley 120: Tension roller 130: Die coater 140: Oven

Claims

1. 1. A method for converting a metal foil web material into an electrode web, comprising: operating a die coater to coat an active material layer onto the metal foil web material; supplying a first portion of metal foil web material from a first supply roll to the die coater; providing a second supply roll carrying a second portion of the metal foil web material; providing adhesive to a leading edge of the second portion of the metal foil web material; attaching a leading end of the second portion of the metal foil web material to a section of the first portion of the metal foil web material such that the adhesive is interposed between the first and second portions of the metal foil web material; and c) cutting the first portion of the metal foil web material from the first supply roll at or behind the adhesive.

2. providing the adhesive including a first section proximal to the tip and a second section distal to the tip; The method of claim 1 , wherein the cutting step occurs in the second section.

3. The method of claim 2 , wherein a gap is provided separating the first section from the second section.

4. The method of claim 2 , wherein the adhesive provides a weaker bond to secure the first portion in the second section than in the first section.

5. The method of claim 2 , wherein the steps of cutting and attaching the tip of the second portion to the first portion are performed using a combined stamping and cutting tool.

6. The method of claim 1 , wherein the die coater is operated to continuously coat active material onto the metal foil web material.

7. the die coater is operated to coat a first side of the metal foil web material, preferably a side of the metal foil web material on which a rear end of the first portion formed by cutting is located; The method of claim 6 , wherein the die coater is positioned downstream of the location where the second portion is applied to the first portion.

8. the die coater is operable to coat a second side of the metal foil web material, preferably a side of the metal foil web material on which the leading end of the second portion is located; The method of claim 7 , wherein the die coater is positioned downstream of the location where the second portion is applied to the first portion.

9. 9. The method of claim 8, wherein a second side of the metal foil web material is coated with the active material after a first side of the metal foil web material is coated with the active material.

10. 10. The method of any one of claims 6 to 9, wherein the active material is coated onto the first side of the metal foil web material directly over the adhesive.

11. 2. The method according to claim 1, wherein the first and second supply rolls supply the same metal foil web material, in particular comprising or consisting of a copper alloy and / or an aluminum alloy.

12. 2. The method of claim 1, wherein the cutting step is performed along a cutting line across the first portion, in particular at an angle of 60° to 120°, preferably at an angle of 80° to 100°, more preferably perpendicular to the direction of movement of the metal foil web material.

13. The method of claim 1 , wherein the cutting step forms a serrated edge along the trailing edge of the first portion.

14. 10. The method of claim 1, wherein the adhesive is provided on a radially outwardly facing surface of the second portion of the metal foil web material on the second supply roll.

15. 2. The method of claim 1, wherein the adhesive is applied to a radially inward facing surface of the first portion of the metal foil web material on the first supply roll.

16. After coating the metal foil web material with the active material layer, a portion of the electrode web containing the adhesive is separated from a portion of the electrode web designated to be used as an electrode; the portion comprises the adhesive and a metal foil web material of 15,000 mm or less, in particular 1,500 mm or less, following the adhesive; The method of claim 1 , wherein the portion is discarded.

17. A machine configured to convert a metal foil web material into an electrode web by the method of any one of claims 1 to 9.

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