System and method for extracting active material residues from an assembly for coating an electrode with an active material layer, and corresponding assembly, electrode manufacturing method, electrode and battery

Abstract

A system for extracting active material residue from an assembly for coating an electrode with an active material layer includes a mobile tank configured to store the active material residue, a conduit attached to the mobile tank and connectable to the assembly, and a pumping device configured to apply a negative pressure to the mobile tank to draw the active material residue from the assembly through the conduit.

Description

[Technical Field]

[0001] The present invention relates to a system and method for extracting active material residues from an assembly for coating an electrode with an active material layer, and to such an assembly configured to allow for the extraction of active material. The present invention also relates to a method for manufacturing an electrode in an assembly for coating an electrode with active material residues, and to the corresponding electrode and battery. [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), plug-in hybrid electric vehicles (P-HEVs), and other vehicles, 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 improved 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 be freely charged and discharged, 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 house an electrode assembly having a structure in which electrodes and separators are alternately arranged in a pouch-shaped case made of a laminated aluminum sheet.

[0005] Secondary batteries can also be classified by their structure, in which negative and positive electrodes are stacked with a separator interposed between them. Typical structures 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-type electrode assemblies and stacked-type electrode assemblies, stack / folded-type electrode assemblies that combine the jelly-roll-type electrode assemblies and stacked-type electrode assemblies have been developed. Such stacked-type electrode assemblies are also called electrode stack assemblies.

[0006] Electrodes, i.e., positive and negative electrodes, are typically formed by coating a metal foil web material with an active material layer, processing it into an electrode web (or electrode for short), and then separating individual electrodes from the coated metal foil web. Because production assemblies typically include large, fixed tanks configured to store a large amount of active material—at least as much as needed for coating—the fixed tanks often contain excess active material. When converting a production assembly from one type of electrode coating to another, such as from a positive electrode to a negative electrode, the active material powder for the coating must be changed accordingly. While such changes are typically made according to a schedule, they sometimes occur unexpectedly, resulting in different amounts of residue. For example, upon completion of a coating operation for producing a positive electrode, some positive active material always remains in the assembly. Before using the same assembly in another coating operation, typically using a different active material for a different negative or positive electrode, the residue must be removed from the assembly, potentially resulting in unwanted impurities in subsequent electrode production. Removing the active electrode material is tedious, is associated with undesirable assembly downtime, and, if done improperly, can produce a reduced quality product in subsequent electrode manufacturing. Summary of the Invention [Problem to be solved by the invention]

[0007] The object of the present invention is to overcome the drawbacks of the prior art by improving the assembly and method, especially in terms of economic and / or ecological aspects. [Means for solving the problem]

[0008] 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.

[0009] Thus, the present invention relates to a system for extracting active material residues, particularly powder residues, from an assembly for coating an electrode with an active material layer. The system includes a mobile tank, a conduit, and a pumping device. It should be noted that the system can be configured to be detachably attached to one or more, preferably several, assemblies for coating an electrode with an active material layer. The system may preferably be mobile, capable of moving from a first assembly for coating an electrode with a first active material (e.g., a positive active material) to a second assembly for coating another electrode with a second active material (e.g., a negative active material). The mobile tank may be provided with a carrier. The carrier may include wheels, rollers, skids, or the like, so that it can be moved between different, separate positions within a manufacturing site. The carrier may be movable on a flat surface, rails, ropes, chains, or the like. The mobile tank may be movable horizontally and / or vertically between different, separate positions within a manufacturing site. The mobile tank may be movable manually. Alternatively or additionally, the mobile tank can include at least one engine and drive system configured to move the mobile tank. The mobile tank preferably includes an electric engine. The assembly is preferably rigidly attached to a support structure, such as a building structure, while the mobile tank is movable relative to the support structure. The system is preferably configured to be attachable to and detachable from the first assembly, the second assembly, and possibly additional assemblies at the manufacturing site. Preferably, the system according to the present invention does not form part of an assembly for coating electrodes with active material during normal coating operations of the assembly. That is, it may be preferable for the system according to the present invention to be distinct and separated from the assembly during normal operation of the assembly. The system may be attachable to an assembly for coating electrodes with active material only after normal coating operations using the assembly have been interrupted, preferably terminated.More specifically, the system can be configured to be attached to the first assembly after the assembly has completed a coating operation, and to be separated from the first assembly before the assembly begins another normal coating operation, preferably using a different active material than before.

[0010] The mobile tank is configured to store the active material residue. The conduit is attached or attachable to the mobile tank and is detachably coupled or connectable to the assembly. The conduit can be tailored to the requirements of the assembly or assemblies to which the system is attachable. The shape and pattern of the conduit can preferably be selected and / or tailored to the system and the assembly or assemblies with which it interacts. For example, the length of the conduit can be appropriately selected. The conduit, or a portion thereof, can be integrally formed with the mobile tank. In some embodiments, the conduit, or a portion thereof, can be realized as a tube, pipe, stub, or the like. The conduit can be attached to the mobile tank, preferably integrally formed with the mobile tank. In one example, the conduit, or a portion thereof, can include or consist of a flexible hose. Such a flexible hose can be attached to the mobile tank or is attached to the mobile tank. The flexible hose can be detachably coupled or connected to the assembly. In some embodiments, the conduit may include a first portion (e.g., a pipe, stub, or bore thereof) integrally formed with the mobile tank and a tube (e.g., a flexible hose) forming a second portion of the conduit.

[0011] The mobile tank can have a volume of at least 50 L, particularly at least 100 L, preferably at least 250 L, and / or not more than 2000 L, particularly not more than 1000 L, preferably not more than 750 L. For example, the mobile tank can have a volume of approximately 500 L. For example, the mobile tank can have a volume of 380 L. In particular, the funnel can have a volume of 280 L. The mobile tank can be selectively sealed or hermetically sealed. In particular, one or more valves can be selectively closed to isolate or open the mobile tank, forming a fluid connection between the interior of the mobile tank and an assembly, a pumping device, a storage container, or the like. Leaks can be prevented by ensuring that the mobile tank is tightly sealed during pumping operations to transfer active material, particularly active material powder residue, from the assembly to the system and controllably release the active material residue, particularly active material powder residue, from the mobile tank, preferably to a storage container. A control valve can be provided between the conduit and the mobile tank. Preferably, the mobile tank includes a control valve configured to open and / or close the connection between the assembly to which the system is attachable or attached and the mobile tank.

[0012] The pumping device of the system is configured to apply a negative pressure to the mobile tank to suck the active material residue from the assembly through the conduit. The pumping device may include a pneumatic drive, particularly a drive connected to the pneumatic supply line of the system. The pumping device is used to propel air or another suitable transport medium, which may be a liquid or gas, to propel the active material residue, particularly active material residue powder, through the conduit. When the system is attached to the first assembly and one of the conduits is attached to the mobile tank and the other is detachably connected to the first assembly (connected state), the pumping device can be operated to suck the active material residue from the assembly. In the connected state, the pumping device can be configured to transport the active material residue from the assembly to the mobile tank.

[0013] The term "negative pressure" as used herein refers to a pressure below ambient pressure and / or below the pressure within the assembly while the system is connected to the assembly. The term "negative pressure" should be understood as a pressure difference between the assembly and the system connected thereto, such that the pumping device is configured to generate a pressure difference between the assembly and the system connected thereto in order to propel the transport medium (e.g., ambient air, nitrogen, or the like) together with the active material, preferably active material residue powder, from the assembly to the mobile tank through a conduit. The term "negative pressure" should preferably be understood as relating to the difference between the assembly on the one hand and the mobile tank of the system on the other hand. In other words, negative pressure should be understood as a pressure lower than (or negative with respect to) a reference pressure, in particular the pressure at the inlet of a conduit connectable or connected to the assembly from which the active material residue, in particular the powder residue, is extracted. Negative pressure may, in some cases, be referred to as vacuum pressure. The pumping device may be configured to generate a pressure difference between the assembly and the mobile tank of 0.01 MPa or more, preferably 0.1 MPa or more, and more preferably 0.5 MPa or more. The pumping device can optionally be configured to generate a pressure difference between the assembly and the mobile tank of 10 MPa or less, particularly 5 MPa or less, and preferably 1 MPa or less. In some embodiments, the pressure difference can be 0.5 MPa to 0.7 MPa, particularly about 0.6 MPa. Additionally or alternatively, the pumping device can be configured to generate an active material residue flow through the conduit (preferably measured at the interface between the conduit and the mobile tank) of at least 1 kg / min, particularly at least 5 kg / min, preferably at least 10 kg / min, more preferably at least 25 kg / min. Additionally or alternatively, the pumping device can be configured to generate a transfer medium flow through the conduit (preferably measured at the interface between the conduit and the mobile tank) of at least 100 NL / min, particularly at least 1000 NL / min, preferably at least 2000 NL / min, more preferably at least 2400 NL / min.Additionally or alternatively, the pumping device can be configured to generate a transfer medium flow through the conduit of 10,000 NL / min or less, particularly 5,000 NL / min or less, preferably 4,000 NL / min or less, and more preferably 3,500 NL / min or less. "NL" or normal liter means a mass unit of gas equivalent to the mass of 1 liter at a pressure of 1 atmosphere (101.325 kPa) and a standard temperature of 20°C. In some embodiments, the system can include a pumping device that generates a relatively higher pressure in the assembly, a pumping device that generates a relatively lower pressure in the system, or both.

[0014] The system according to the present invention allows for the collection of active material residues, particularly powder residues, from an assembly for coating an electrode web with an active material layer, cleaning the assembly for subsequent operations, preferably using a different active material, and / or collecting the active material residues, particularly powder residues, for future use in the same assembly or a different assembly for coating an electrode web with an active material layer. By using the system, the assembly can be particularly well prepared for future operations using a different type of active material, which may be affected by impurities originating from the active material residues. This allows for the rapid start of a subsequent coating operation using a second active material that is different from, and particularly incompatible with, the first active material previously present in the assembly. If the electrode web coated with the active material layer contains impurities that negatively affect performance, the electrode or battery containing the electrode may not meet quality requirements, which may result in a substandard product.

[0015] Removing or extracting the active material residue from the assembly and collecting it in a mobile tank lays the foundation for the possible future use of the active material residue. Typically, in electrode manufacturing, the active material residue is considered waste to be disposed of. Disposing of the active material residue is undesirable for both economic and ecological reasons. The system according to the present invention makes it possible to significantly improve the economic and ecological footprint of an assembly for coating an electrode web with an active material layer.

[0016] In one embodiment, the pumping device is disposed in the mobile tank. The pumping device can be securely attached to the mobile tank. For example, the pumping device can be attached to the vertical top lid of the funnel or any cylinder optionally attached thereto.

[0017] In some embodiments, the system may additionally include a storage container that can be attached to and detached from the mobile tank. In other words, the storage container is detachably attached to the mobile tank. The storage container is configured to contain and store active material residue. The storage container is preferably selected to be suitable for storing active material residue, preferably active material powder residue. The storage container may preferably be selected for physical and / or chemical compatibility with the active material residue stored therein. The system may include multiple storage containers each configured for a different type of active material residue. For example, the system may include a first storage container corresponding to a first active material, a second storage container for a second active material, etc. In particular, the storage container may be configured so as not to chemically interact with the active material stored therein. Preferably, the storage container includes or is made of a material that is chemically inert to the active material stored therein. In a preferred embodiment, the storage container is realized using the shipping packaging in which the active material residue extracted from the assembly was initially provided as the active material to the assembly. Preferably, the storage container is attachable to a lower side of the mobile tank. In particular, the storage container can be positioned vertically below the mobile tank. The storage container can be connected or connectable to a lower side, particularly the bottom, of the mobile tank. The bottom of the mobile tank can be at least partially surrounded by the storage container. The lower side can generally refer to a portion of the mobile tank that is in the lower vertical half of the mobile tank, particularly the lower vertical third or lower quarter. The storage container can be attached to the bottom end of the mobile tank, or alternatively, to a portion of the storage container near the bottom end of the mobile tank, particularly a portion that extends upward from the bottom end of the mobile tank.

[0018] In a preferred embodiment of the present invention, the mobile tank can include a cylindrical portion and a funnel portion. In particular, the mobile tank includes a funnel portion and / or a discharge valve on the lower side of the mobile tank. The funnel can form the bottom of the mobile tank and form the lower side of the mobile tank. The cylindrical portion can be positioned vertically above the funnel. It may be preferable for the cylindrical portion to have a shape complementary to the wide end of the funnel. The narrow end of the funnel can have a diameter equal to or greater than, and preferably larger than, the diameter of one or more pressure supply lines used in the conduits and / or system. The pressure supply line can be used to operate a pumping device. For example, the pumping device can have a supply line with a diameter of 1 inch (2.54 cm). In a preferred embodiment, the width of the narrow end of the funnel, particularly the width of the discharge valve, is 2 inches (5 cm) to 20 inches (50 cm), preferably 6 inches (15 cm) to 12 inches (30 cm), for example 8 inches (20 cm). The funnel and / or cylinder may have a diameter at the wide end of the funnel of 250 mm to 2500 mm, in particular 500 mm to 1500 mm, operationally 1000 mm to 1200 mm.

[0019] The funnel can be provided in the mobile tank to easily drain the active material residue, preferably into a storage container. Providing a drain valve on the lower side of the mobile tank, particularly at the lower end (narrow end) of the funnel, can be beneficial to the operation of the system or method for extracting active material residue.

[0020] In some embodiments, the mobile tank includes a vibrator and / or a flow digger configured to facilitate the evacuation of active material residues from the mobile tank, particularly into a storage container. It may be preferred that the flow digger and / or the vibrator include a respective pneumatic drive, particularly a drive connected to a pneumatic supply line of the system. The vibrator and / or the flow digger for evacuation of the active material may be provided in particular in a system for extracting active material powder residues from an assembly. The flow digger and / or the vibrator may improve the speed at which the active material residues can be evacuated from the mobile tank. Thus, the system or method for extracting active material can be operated quickly and therefore particularly efficiently.

[0021] In some embodiments that can be combined with the above-described embodiments, the pumping device is a vacuum conveyor including a vacuum pump. The pumping device that is a vacuum conveyor can also further include a filter between the pumping device, particularly the vacuum conveyor, and the mobile tank. The filter can serve to prevent the vacuum pump from sucking in active material residue, particularly powdery residue. Additionally or alternatively, the system, particularly the pumping device, includes a dust collector, particularly a dust collector connected to an exhaust port of the pumping device. The dust collector protects the environment from active material powder residue dust. The pumping device including the vacuum conveyor is preferably attached to the mobile tank so as to be operated to suck secondary active material residue from the assembly into the mobile tank via a conduit.

[0022] In a preferred embodiment of the system according to the present invention, which can be combined with the above-described embodiments, the conduit can be or is directly connected to the stationary tank, hopper, scale, mixer, and / or die coater of the assembly. Preferably, the conduit can be or is directly connected to the hopper or a conveyor directly connected to the hopper of the assembly. It may be preferable to remove the mixer and / or die coater in which an active material slurry containing liquid components such as binders and / or solvents together with the active material powder is used before extracting the active material powder residue from the assembly. It may also be preferable to remove the scale for measuring and / or weighing the active material before installing the system, or at least seal the scale of a separate feeding device from the system before operating the system to extract the active material (powder) residue from the assembly to prevent measurement errors on the scale. In particular, it may be preferable to configure the system to be connected or connectable to a subsystem of the assembly for coating the electrodes with an active material layer, including a stationary tank and / or hopper for the active material (powder) and, optionally, a conveyor for transporting the active material powder from the tank and / or hopper to a scale and / or mixer or similar location. Such an attachment can minimize the amount of active material (powder) residue that may remain inside the assembly after an extraction operation using the system according to the invention. Furthermore, using a system and connecting it in this manner allows the assembly to be quickly and efficiently cleaned of active material residue before starting a subsequent coating operation on the assembly using a different active material.

[0023] The present invention also relates to an assembly for coating an electrode with an active material layer. The assembly includes a stationary tank, a die coater, and a conveyor. The assembly can include additional assembly components, preferably stationary assembly components. The stationary tank can be fixedly attached to a support structure, such as a building structure. Preferably, the die coater and / or the conveyor are fixedly attached to a support structure, such as a building structure. The stationary tank is configured to store a feed active material to be processed by the assembly. The stationary tank can have a volume of at least 500 L, particularly at least 1000 L, preferably at least 2500 L, and / or not more than 100,000 L, particularly not more than 50,000 L, preferably not more than 20,000 L. As mentioned above, a system for extracting active material residue from the assembly can be attachable or can be attached to the assembly. In such cases, it may be preferable that the mobile tank of the extraction system is not larger than the stationary tank of the coating assembly. More preferably, the mobile tank can have a volume smaller than the volume of the stationary tank, particularly not more than half the volume of the stationary tank. The die coater is configured to supply active material onto the metal foil web material to form an active material layer. The stationary tank can be positioned vertically above the die coater. The stationary tank is preferably immovable. The conveyor is configured to transport the active material from the stationary tank to the die coater. The conveyor can include at least one conduit for fluid communication between the die coater and the stationary tank.

[0024] According to the present invention, the assembly also includes an outlet portion. The outlet portion is preferably a fixed component of the assembly. The outlet portion is configured to selectively close or open an outlet for discharging the active material from the assembly. A system for extracting active material residue from the assembly, particularly the above-mentioned system, can be or is removably attached to the outlet portion. In particular, the system includes a conduit removably connected to the assembly. The conduit of the system can preferably be connectable to the outlet of the assembly.

[0025] In one embodiment of the assembly, the outlet has a closed state and an open state. Preferably, the outlet is configured to selectively close or open the outlet depending on the open or closed state of the outlet. In the closed state of the outlet, the active material can freely flow from the stationary tank to the die coater. In addition, in the closed state, the active material is inhibited from exiting the assembly through the outlet. In the open state, the outlet is in fluid communication with the stationary tank, allowing the active material to exit the assembly through the outlet. In particular, in the open state, the stationary tank can be in fluid communication with the system, preferably its mobile tank, through the open outlet while the system is attached to the assembly.

[0026] According to a further development of the assembly, the outlet is configured in an open state to inhibit the transfer of active material from the stationary tank to the die coater. In a closed state of the outlet, the outlet can provide a separation between the stationary tank and / or the discharge port and the die coater. In a closed state of the outlet, it may be preferable for the outlet to provide a fluid-tight and / or gas-tight barrier between the stationary tank on the one hand and the scale and / or mixer of the assembly on the other hand. Additionally or alternatively, in a closed state of the outlet, the outlet provides a fluid-tight and / or gas-tight barrier between the discharge port on the one hand and the scale and / or mixer of the assembly on the other hand.

[0027] In a preferred embodiment of the assembly, which can be combined with the above-mentioned embodiments and further developments, the outlet comprises a T-piece. In particular, the outlet can comprise a branched T-valve and / or a three-way stopcock.

[0028] In one embodiment of the assembly which can be combined with the above-mentioned embodiments and further developments, the outlet is located below the stationary tank and the extraction of active material from the assembly to the system can be assisted by gravity.

[0029] Additionally or alternatively, some assembly embodiments further include a hopper attached to the stationary tank and positioned at the bottom of the stationary tank. It may be preferable for the stationary tank to be provided with a hopper to improve the flow of active material to the die coater via the conveyor. The outlet is positioned below the hopper. Thus, active material extraction from the stationary tank to the system can additionally or alternatively be assisted by the hopper.

[0030] The assembly may include a scale for measuring and / or dosing the active material. Alternatively or additionally, the assembly may include a mixer configured to combine the active material with other components, particularly liquid components, to form a slurry. The scale and / or mixer are located between the stationary tank and the die coater. It may be preferable for the scale to be located upstream of the mixer. An outlet section is located upstream of the scale and / or mixer. The conveyor may be separated into a powder conveyor section and a slurry conveyor section by the mixer, where the outlet section is preferably located in the powder conveyor section.

[0031] The present invention also relates to a method for extracting active material residues from an assembly for coating an electrode with an active material layer, in particular a method using the above-mentioned system and / or assembly, which may preferably be carried out to extract active material residues from a first assembly and subsequently inject the active material residues into another assembly or to reintroduce the active material residues into the first assembly.

[0032] An assembly for coating an electrode with an active material layer can include a stationary tank in which the active material can be stored for processing, a conveyor configured to transport the active material (powder) through the assembly, a scale or other dosing device for measuring the amount of active material being processed for coating, and a mixer configured to combine the active material powder with other ingredients, particularly liquid ingredients, to form a slurry. The other ingredients can include binders, conductive materials, and / or solvents, among others. The assembly for coating an electrode with an active material layer can include at least one die coater in which an active material slurry, which can be prepared in a mixer, is dispensed onto the electrode in the form of an electrode web to form the active material layer.

[0033] The assembly may additionally or alternatively include one or more conveyors for the active material, in particular active material powder and / or active material slurry. The conveyor of the assembly for coating the electrode with the active material layer may include a vacuum conveyor. It should be clear that the pumping device of the system according to the invention, in particular the vacuum conveyor, is preferably a separate unit from the conveyor of the assembly. Preferably, when the system according to the invention is coupled to an assembly, the combination of the system and the assembly may include two different vacuum conveyors, one of which implements the pumping device of the system and the other of which is the conveyor of the assembly that is operational for the normal coating operation. Alternatively, when an assembly is prepared for coupling to the system according to the invention by separating two or more subsystems from the assembly, a system including a pumping device, which may be a vacuum conveyor, may be coupled to a first subsystem of the assembly, and a second subsystem of the assembly includes a vacuum conveyor of the assembly that is different from the pumping device of the system.

[0034] A method for extracting active material residue from an assembly for coating an electrode with active material, preferably the assembly described above, includes the steps of providing a mobile tank, attaching a conduit to the mobile tank, connecting the conduit to the assembly, and drawing the active material residue from the assembly to the mobile tank via the conduit.

[0035] In the method for extracting active material residue, it may be preferred that the conduit is first attached to the mobile tank. The conduit may be attached to the mobile tank in a permanent manner, such as by welding. The conduit is preferably connected to the assembly after the conduit is attached to the mobile tank. It may be preferred that the conduit is connected to the assembly in a detachable manner.

[0036] The active material residue is sucked from the assembly after the conduit is attached to the mobile tank and connected to the assembly, preferably to the assembly's outlet. Before sucking the active material, it may be considered to test whether the fluid system, including the mobile tank, the conduit, the assembly, and / or the subsystem of the assembly from which the active material residue must be extracted, is hermetically sealed to prevent leakage of a transfer medium such as air, nitrogen, or the like. If ambient air is used as the transfer medium, it may be appropriate to preferably controllably open at least one hole, such as an air inlet, of the assembly or the subsystem of the assembly from which the active material residue must be extracted before starting to suck the active material residue from the assembly.

[0037] One embodiment of the method for extracting active material residue can include opening a selectively closable outlet of the assembly to allow active material residue of the assembly to move through an outlet of the outlet to the mobile tank. The outlet can be actuated to switch between a closed state in which the active material residue is inhibited from moving from the fixed tank to the mobile tank through the outlet, and an open state in which the active material residue can move from the fixed tank to the mobile tank through the outlet.

[0038] In a preferred embodiment of the method for extracting active material residue, the additional step includes discharging the active material residue from the mobile tank into a storage container. Prior to discharging the active material residue from the tank into the container, the storage container can be detachably connected to the mobile tank, particularly in an airtight manner. Discharging the active material residue from the mobile tank into the storage container can be assisted by discharging the material into the storage container through a funnel toward the bottom of the mobile tank. Alternatively or additionally, the mobile tank can be equipped with a vibrator and / or a fluid degger configured to facilitate the discharge of the active material residue from the mobile tank. It may be preferable to operate the fluid degger and / or the vibrator associated with the fixed tank, particularly intermittently or continuously, during the discharge of the active material residue from the mobile tank into the storage container. In some preferred embodiments, a discharge valve can be provided on the mobile tank. It may be preferable to operate the discharge valve to start and / or stop the discharge of the active material from the mobile tank into the storage container. In preferred embodiments, the active material residue can be discharged from the mobile tank into the storage container via the discharge valve.

[0039] In a particularly preferred embodiment of a method for extracting active material residues from an assembly for coating an electrode, which can be combined with the above, connecting the conduit to the assembly comprises connecting the conduit to one of a stationary tank, a hopper, a scale, a mixer, and / or a die coater of the assembly, in particular directly to the hopper.

[0040] The present invention also relates to a method for manufacturing an electrode using a mixture of an active material and an active material residue in an assembly for coating the electrode with an active material layer. For ease of understanding, this mixture can be referred to as a mixture of a first active material and a second active material. In the method according to the present invention, the second active material is composed of the active material residue. The mixture of the first active material and the second active material can be generated before, during, or after mixing the first active material and / or the second active material with a fluid component, which may include, in particular, a binder and / or a solvent, in a mixer of the assembly. In some embodiments, mixing of the first active material and the second active material can be performed by dry mixing the powders of the first active material and the second active material. The dry mixing of the powders of the first active material and the second active material can be performed inside the assembly, for example, in a stationary tank, hopper, and / or conveyor of the assembly. According to another embodiment of the method, the dry mixing of the powders of the active materials can be performed before introducing the mixture of the first active material and the second active material into the assembly, in particular into the stationary tank and / or hopper of the assembly. It may be preferred that the first active material (powder) is different from the second active material (powder). The first active material may include a first marker to distinguish the first active material from the second active material. Alternatively or additionally, the second active material may include a marker, in particular a second marker, preferably to distinguish the second active material from the first active material. It may be preferred that both the first and second active materials include the respective first and second markers. In some preferred embodiments, only the second active material (extracted active material residue) includes a marker.

[0041] Preferably, the method of manufacturing an electrode uses the active material residue extraction method described above to provide an active material residue. Preferably, the active material residue is extracted from the same assembly or a different assembly than that used in the method of manufacturing an electrode.

[0042] An additional development of the method for manufacturing an electrode includes preparing a mixture containing 0.01% to 25% by weight of active material residue. In particular, this preparation step can produce a mixture containing 0.1% to 10% by weight of active material residue. As mentioned above, this mixture may preferably be a powder mixture containing an active material powder (first active material powder) and an active material residue powder (second active material powder), where the content of the active material residue can be determined relative to the total weight of the powder mixture. In the case of a wet active material mixture containing a liquid component such as a solvent, binder, or the like, the content of the second active material can be determined relative to the total dry content of the wet mixture.

[0043] In the method for producing an electrode, the content of active material residue in the mixture can be constant throughout the coating operation. In a preferred embodiment of the method for producing an electrode using a mixture of active material and active material residue to assemble the electrode for coating it with active material, it may be preferable to reduce the content of active material residue. In particular, the content of active material residue can be reduced from an initial value of about 10 wt %, particularly 20 wt % or more, to a second active material residue content of less than 10 wt %, particularly less than 5 wt %. In the method for producing an electrode, the content of active material residue can be reduced to a final active material residue content of less than 1%, particularly less than 0.1%, preferably less than 0.01 wt %.

[0044] The present invention also relates to a method for manufacturing a battery using a mixture of an active material and an active material residue. The battery may be, for example, a pouch-type battery or a jelly roll-type battery. The battery may include a stacked or wound, particularly roll-shaped, electrode assembly including a positive electrode that may include the active material residue, a negative electrode that may include a second active material residue, and a separator between the positive and negative electrodes.

[0045] The present invention also relates to an electrode comprising a sheet electrode and an active material layer coated on the sheet electrode, wherein the active material layer comprises a mixture of active material and active material residue.

[0046] Additionally, the present invention relates to a battery including the above-described electrode.

[0047] <Battery>

[0048] A battery generally includes two electrodes of opposite polarity, i.e., a negative electrode and a positive electrode. The electrodes are arranged 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, allowing a chemical reaction that releases electrical energy. Each electrode of the battery may include a corresponding foil. The foil may include or be made of an electrically conductive material. In particular, the foil may be made of or include a metal or metal alloy that is made of or includes aluminum or copper. It may be preferable for at least one electrode of the battery to be realized as a foil coated with an active electrode material (abbreviated as active material).

[0049] 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 be provided with 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 slurry or active material layer can include conductive additives, binders, fillers, and other ingredients. The positive electrode active material can be configured to be rechargeable. The process of releasing ions from the positive electrode active material and storing 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 is generally referred to as charging or recharging. The active materials used in battery electrodes are considered essential in determining battery characteristics such as capacity, voltage, and memory effect.

[0050] In the present invention, the positive electrode active material coated on the positive electrode sheet and the negative electrode active material coated on the negative electrode sheet may include, without limitation, any active material known in the technical field related to the present invention. The electrode sheet may be prepared by cutting a portion from an electrode web.

[0051] The term "web material" should be understood as a general term referring to a web-like material such as a film, sheet, foil, net, sieve, foam, nonwoven fabric, or other porous material, or the like. The web material has a web length dimension substantially greater than the web width dimension, which is substantially greater than the 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. The typical moving speed of the web material during processing, particularly during the coating step, can be as high as 100 m / min.

[0052] <Positive electrode>

[0053] The positive electrode preferably contains an active material powder, particularly a positive electrode active material powder. Specifically, the positive electrode includes a positive electrode current collector and a positive electrode active material layer formed on the positive electrode current collector, and the positive electrode active material layer contains the positive electrode active material powder.

[0054] In one 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 keep the compound electrically neutral).

[0055] In another example, 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 preferably contains at least one element having an average tetravalent oxidation state; 0 ≦ x ≦ 1).

[0056] In yet 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 to keep the compound electrically neutral), or Li3M2(PO4)3 (M contains at least one selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg and Al).

[0057] Preferably, the positive electrode active material can include primary particles and / or secondary particles formed by aggregation of primary particles.

[0058] In one example, the negative electrode active material can include a carbon material, a lithium metal or a lithium metal compound, silicon or a silicon compound, and tin or a tin compound. TiO 2とA metal oxide having a potential of less than 2 V, such as SnO2, can be used as the negative electrode active material. The carbon material can include low-crystalline carbon and high-crystalline carbon.

[0059] The positive electrode current collector may include a highly conductive metal and is not particularly limited as long as it is easily attached to the positive electrode active material layer and is non-reactive within the battery voltage range. Examples of the positive electrode current collector include stainless steel, aluminum, nickel, titanium, heat-treated carbon, aluminum or stainless steel surface-treated with carbon, nickel, titanium, silver, or the like. The positive electrode current collector generally has a thickness of 3 μm to 500 μm and may have fine irregularities on its surface to enhance the adhesion of the positive electrode active material. For example, the positive electrode current collector may be used in various forms, such as a film, sheet, foil, mesh, porous material, foam, or nonwoven fabric.

[0060] In this case, the positive electrode active material powder may be contained in an amount of 80% to 99% by weight, more specifically 85% to 98.5% by weight, based on the total weight of the positive electrode active material layer. When the positive electrode active material powder is contained in the above amount, excellent capacity characteristics can be exhibited.

[0061] The conductive material is used to impart conductivity to the electrode. Any conductive material that is conductive without causing chemical changes in the battery can be used without any particular limitation. Specific examples include graphite, such as natural graphite or artificial graphite; carbon-based materials, such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, and carbon fiber; metal powders or fibers, such as copper, nickel, aluminum, and silver; conductive tubes, such as carbon nanotubes; conductive whiskers, such as zinc oxide and potassium titanate; conductive metal oxides, such as titanium oxide; and conductive polymers, such as polyphenylene derivatives. These can be used alone or in combination. The conductive material can be included in an amount of 0.1 wt % to 15 wt % based on the total weight of the positive electrode active material layer.

[0062] The binder improves the cohesive strength between positive electrode active material particles and the adhesive strength between the positive electrode active material and the current collector. Specific examples include polyvinylidene fluoride (PVDF), polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinyl alcohol, polyacrylonitrile, polymethyl methacrylate, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), fluororubber, polyacrylic acid, polymers in which hydrogen is substituted with Li, Na, or Ca, and various copolymers thereof. These can be used alone or in combination. The binder can be included in an amount of 0.1 wt% to 15 wt% based on the total weight of the positive electrode active material layer.

[0063] The positive electrode can be manufactured by a typical positive electrode manufacturing method using a positive electrode active material powder. Specifically, the positive electrode can be manufactured by dissolving or dispersing the positive electrode active material powder and, optionally, a binder, a conductive material, and a dispersant in a solvent to prepare a positive electrode slurry composition, coating the positive electrode current collector with the slurry, drying it, and rolling it.

[0064] The solvent may be a solvent commonly used in this field, such as dimethyl sulfoxide (DMSO), isopropyl alcohol, N-methylpyrrolidone (NMP), dimethylformamide (DMF), acetone, water, etc., which may be used alone or in combination of two or more. The amount of solvent used is sufficient to dissolve and disperse the positive electrode active material, conductive material, binder, and dispersant, taking into account the thickness of the applied slurry and production yield, and to enable viscosity that can exhibit excellent thickness uniformity when applied to produce a positive electrode.

[0065] <Negative electrode>

[0066] The negative electrode preferably contains an active material powder, particularly a negative electrode active material powder. Specifically, the negative electrode includes a negative electrode current collector and a negative electrode active material layer formed on the negative electrode current collector, and the negative electrode active material layer contains the negative electrode active material powder.

[0067] In a battery, particularly a lithium secondary battery, the negative electrode includes a negative electrode current collector and a negative electrode active material layer located on the negative electrode current collector.

[0068] The negative electrode current collector is not particularly limited as long as it has high conductivity without causing chemical changes in the battery. For example, copper, stainless steel, aluminum, nickel, titanium, heat-treated carbon, copper or stainless steel surface-treated with carbon, nickel, titanium, silver, or the like, aluminum-cadmium alloy, or the like can be used. The negative electrode current collector generally has a thickness of 3 μm to 500 μm. Similar to the positive electrode current collector, the negative electrode current collector can have fine irregularities on its surface to enhance adhesion of the negative electrode active material. For example, the negative electrode current collector can be used in various forms, such as a film, sheet, foil, mesh, porous material, foam, or nonwoven fabric.

[0069] The negative electrode active material layer contains a negative electrode active material, and optionally a binder and a conductive material.

[0070] The negative electrode active material may be a compound capable of reversibly inserting and extracting lithium. Specific examples thereof include carbon-based materials such as artificial graphite, natural graphite, graphitized carbon fiber, and amorphous carbon; metal compounds capable of alloying with lithium such as Si, Al, Sn, Pb, Zn, Bi, In, Mg, Ga, Cd, Si alloys, Sn alloys, and Al alloys; and SiO. βMetal oxides capable of lithium doping and dedoping, such as SnO2, vanadium oxide, and lithium vanadium oxide (0<β<2), and composites containing metal compounds and carbon-based materials, such as Si-C composites and Sn-C composites, can be used alone or in combination. Lithium metal thin films can also be used as negative electrode active materials. Additionally, both low-crystalline and high-crystalline carbons can be used as carbon materials. Typical examples of low-crystalline carbons include soft carbon and hard carbon, while typical examples of high-crystalline carbons include amorphous, plate-like, flake-like, spherical, or fibrous natural graphite, artificial graphite, kish graphite, pyrolytic carbon, mesophase pitch-based carbon fibers, mesocarbon microbeads, mesophase pitch, and high-temperature-calcined carbons such as coke derived from petroleum or coal tar pitch.

[0071] The negative electrode active material may be contained in an amount of 80% by weight to 99% by weight based on the total weight of the negative electrode active material layer.

[0072] The binder helps to bond the conductive material, active material, and current collector together, and is generally included in an amount of 0.1 to 10% by weight based on the total weight of the negative electrode active material layer. Examples of binders include polyvinylidene fluoride (PVDF), polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated EPDM, styrene-butadiene rubber, nitrile-butadiene rubber, fluorine rubber, and various copolymers thereof.

[0073] The conductive material is a component for improving the conductivity of the negative electrode active material and may be contained in an amount of 10 wt % or less, preferably 5 wt % or less, based on the total weight of the negative electrode active material layer. There are no particular limitations on the conductive material, as long as it is conductive and does not cause chemical changes in the battery. Examples of conductive materials that can be used include graphite, such as natural graphite and artificial graphite; carbon black, such as acetylene black, ketjen black, channel black, furnace black, lamp black, and thermal black; conductive fibers, such as carbon fiber and metal fiber; fluorocarbon; metal powders, such as aluminum and nickel; conductive whiskers, such as zinc oxide and potassium titanate; conductive metal oxides, such as titanium oxide; and polyphenylene derivatives.

[0074] The negative electrode can be manufactured by a typical negative electrode manufacturing method using a negative electrode active material powder. Specifically, the negative electrode can be manufactured by dissolving or dispersing the negative electrode active material powder and, optionally, a binder, a conductive material, and a dispersant in a solvent to prepare a negative electrode slurry composition, coating the negative electrode current collector with the slurry, drying the slurry, and rolling the slurry.

[0075] The negative electrode active material layer can be formed by coating a negative electrode slurry composition, which is prepared by dissolving or dispersing a negative electrode active material and, optionally, a binder and a conductive material in a solvent, on a negative electrode current collector and drying the composition, or by casting the negative electrode slurry composition on a separate support, removing the composition from the support, and laminating the resulting film on the negative electrode current collector.

[0076] <Active material powder>

[0077] The active material powder may include an active material powder, such as a lithium transition metal oxide, containing a metal oxide in the form of a single particle composed of one nodule and / or a quasi-single particle, which is a composite of 30 or less, preferably 2 to 20, and more preferably 2 to 10 nodules. Active material powders containing a metal oxide in the form of a single particle and / or a quasi-single particle, such as a lithium transition metal oxide, have higher particle strength than existing lithium transition metal oxides in the form of secondary particles formed by agglomerations of tens to hundreds of primary particles, and are therefore less likely to be destroyed during rolling.

[0078] In addition, active material powders containing metal oxides in the form of single particles or pseudo-single particles, such as lithium composite transition metal oxides, have a small number of components (i.e., nodules) that make up the single particles and / or pseudo-single particles, so changes due to volume expansion / contraction of the components (i.e., nodules) during charging and discharging are small, and therefore the occurrence of cracks inside the particles is substantially reduced.

[0079] In the present invention, a "single particle" refers to a particle composed of a single nodule. In the present invention, a "quasi-single particle" refers to a particle that is a complex formed from 30 or fewer nodules. A "nodule" according to the present invention refers to a particle unit that constitutes a single particle and a quasi-single particle. A nodule may be a single crystal with no grain boundaries, or a polycrystal in which no grain boundaries are apparent when observed under a scanning electron microscope (SEM) at a magnification of 5,000 to 20,000 times.

[0080] In the present invention, the term "secondary particles" refers to particles formed by agglomeration of tens to hundreds of primary particles. More specifically, secondary particles are agglomerations of 50 or more primary particles.

[0081] In the present invention, when "particles" are described, any one or all of single particles, quasi-single crystals, primary particles, nodules, and secondary particles may be included.

[0082] In the present invention, "D mean」refers to the average particle diameter of the nodules measured using an electron backscatter diffraction (EBSD) pattern analyzer. EBSD analysis is performed by manufacturing an electrode using the positive electrode active material powder to be measured, cutting the electrode using ion milling (HITACHI IM-500, accelerating voltage: 6 kV) before the rolling process to obtain a cross section, and then measuring the cross section using an FE-SEM device (JEOL JSM-7900F). In this case, measurements are performed at an accelerating voltage of 15 kV and a WD of 15 mm on a primary particle scale of approximately 400 ± 10 particles. The active material powder has an average particle diameter (D) of 0.5 μm to 3.5 μm. mean ) can be included. Specifically, D mean may be 0.5 μm or more, 1.0 μm or more, or 1.5 μm or more, and D mean The average particle diameter (D) of the nodules may be 3.5 μm or less, 3 μm or less, 2.5 μm or less, or 2.0 μm or less. mean When the diameter of the positive electrode active material is less than 0.5 μm, the specific surface area of ​​the positive electrode active material increases, and side reactions with the electrolyte may increase. mean When the particle size exceeds 3.5 μm, the (lithium) mobility in the positive electrode active material decreases, and the output characteristics of the battery may decrease.

[0083] In the present invention, "D 50 " means the particle size corresponding to 50% of the cumulative volume in the particle size distribution of the active material powder. 50 ) can be measured by a laser diffraction method. For example, the average particle diameter can be measured by dispersing the positive electrode active material powder in a dispersion medium and irradiating the resulting material with a commercial laser.

[0084] The active material powder is D, which is the value corresponding to 50% of the cumulative volume in the particle size distribution of the powder. 50 Specifically, D 50 may be 2 μm or more, 3 μm or more, 4 μm or more, 5 μm or more, or 6 μm or more, and D 50 may be 10 μm or less, 9 μm or less, 8 μm or less, or 7 μm or less. 50When the D is less than 2 μm, the specific surface area of ​​the entire positive electrode active material increases, which may increase side reactions with the electrolyte. 50 When the particle size exceeds 10 μm, the lithium mobility in the positive electrode active material decreases, and the output characteristics of the battery may decrease.

[0085] The active material powder may contain one or more markers. The markers may be used to distinguish the first active material powder from the second active material powder. In particular, the markers may be used to distinguish the new active material powder from the active material residue. The one or more markers are preferably selected so as not to have a detrimental effect on the active material. It may be preferable that the active material powder, particularly the active material powder residue, contains the marker in an amount of 0.01 wt % to 5 wt %, particularly 0.02 wt % to 2 wt %, and preferably 0.05 wt % to 1 wt %. In some preferred embodiments, the active material powder, particularly the active material powder residue, contains less than 1 wt %, particularly less than 0.5 wt %, preferably less than 0.2 wt % or less than 0.1 wt %. A positive electrode marker may be provided to distinguish different positive electrode active material powders. The positive electrode marker may preferably include or consist of a material different from the positive electrode active material. A negative electrode marker may be provided to distinguish different negative electrode active material powders. The negative electrode marker may preferably comprise or consist of a material different from the negative electrode active material.

[0086] In some embodiments, the marker may comprise or consist of a metal oxide, such as lithium oxide for LiCoO2, Li(NiCoMn)O2, Li(NiCoAl)O2, LiMn2O, and / or LiFePO4. Alternatively or additionally, the marker may comprise a carbon-based material, such as artificial graphite, natural graphite, graphitized carbon fiber, amorphous carbon, among others; metal compounds capable of alloying with lithium, such as Si, Al, Sn, Pb, Zn, Bi, In, Mg, Ga, Cd, Si alloys, Sn alloys, Al alloys; SiO β (0<β<2), metal oxides such as SnO2, vanadium oxide, and lithium vanadium oxide ;The composite material may include or consist of one or more of the following composites containing a metal compound and a carbon-based material, such as Si-C composites and Sn-C composites, which may be used alone or in combination of two or more.

[0087] 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]

[0088] According to embodiments, a system and method can be provided for extracting active material residues from an assembly for coating an electrode (web) with an active material layer, which allows the active material to be saved and reused so that the assembly can be operated in an economically and ecologically improved manner. According to embodiments, economic and ecological advantages can be exploited in batteries, electrodes, and electrode manufacturing methods that use a mixture of (new) active material and active material residues.

[0089] The effects of the present invention are not limited to the effects described above, and other effects not described above can be clearly understood by those skilled in the art from the description of the attached claims. [Brief explanation of the drawings]

[0090] [Figure 1] FIG. 1 is a schematic diagram of an assembly for coating an electrode with an active material layer. [Figure 2] 1 is a schematic diagram of a system coupled to a subsystem of the assembly for extracting active material residue from the assembly. [Figure 3] FIG. 1 is a schematic diagram of a system for extracting active material residue from an assembly. [Figure 4] FIG. 2 is another schematic diagram of a system for extracting active material residue. DETAILED DESCRIPTION OF THE INVENTION

[0091] 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, which may be modified in various different ways and are not limited to the embodiments set forth herein.

[0092] In order to clearly explain the present invention, parts not relevant to the description will be omitted, and the same reference numerals will refer to the same elements throughout the description. The marker is preferably different from the main component of the active material powder. The marker can preferably be introduced into the active material residue extracted from the system, particularly the mobile tank or storage vessel. In some embodiments, the marker can be formed in the active material residue during extraction in the assembly and / or storage in the mobile tank and / or storage vessel. In some embodiments, the marker can be added to the active material during preparation of the active material before it is extracted from the assembly into the active material residue.

[0093] Furthermore, the size and thickness of each element in the drawings are arbitrarily shown for convenience of explanation, and the present invention is not necessarily limited to those shown in the drawings. The thicknesses of layers, regions, etc. in the drawings are exaggerated for clarity. The thicknesses of some layers and regions in the drawings are exaggerated for convenience of explanation.

[0094] Furthermore, when an element such as a layer, film, region, or plate is referred to as being "on" or "on top of" another element, it can be understood that it may be directly on the other element, or that intervening elements may be present. Conversely, when an element is referred to as being "directly on" another element, it means that no other intervening elements are present. Furthermore, the words "on" or "on" mean that the element is disposed above or below a reference portion, and do not necessarily mean that the element is disposed at the top end of the reference portion in the direction opposite to gravity. Meanwhile, descriptions of being "higher," "on," or "on top" as well as descriptions of being "lower," "under," or "bottom" can also be understood with reference to the above content.

[0095] Also, throughout the description, references to a "plan view" mean a view of the target portion from above, and references to a "cross-sectional view" mean a view of the target portion from the side of a vertically cut cross section.

[0096] Throughout the description, when a part is referred to as "comprising" or "consisting of" a particular element, this means that it may additionally include other elements without excluding other elements, unless expressly stated otherwise. Throughout the specification, each element may be singular or plural, unless expressly stated otherwise.

[0097] Furthermore, when elements are said to be "connected," "coupled," or "linked" to other elements, it is understood that the elements may be directly connected or coupled to the other elements, but there may be intervening elements between the elements, or the elements may be "connected," "coupled," or "linked" to each other through different elements.

[0098] Throughout the specification, "A and / or B" means A or B or both A and B unless otherwise specified, and "C through D" means greater than or equal to C and less than or equal to D unless otherwise expressly stated.

[0099] A system and method for extracting active material residues, and a method for coating an electrode with an active material layer to manufacture a battery and a corresponding assembly will now be described with reference to the accompanying drawings.

[0100] For purposes of illustration, FIG. 1 shows an assembly 100 configured to process a metal foil web material 101 into an electrode web 102. In other words, FIG. 1 illustrates the normal coating operation mode of the assembly 100. The metal foil web material 101 typically has a thickness of only a few microns, a width of a few centimeters, and a length that can reach 1 km or more. The metal foil web material 101 is provided from a supply and transported through the assembly 100 along a transport direction T indicated by the arrow. The metal foil web material 101 passes through a die coater 110 configured and operative to apply an active material layer 103 to the metal foil web material to form an electrode or electrode web 102. Downstream of the die coater 110, an oven (not shown) can be provided to cure the active material layer 103 to stabilize the electrode web 102.

[0101] In the schematic diagram of assembly 100 shown in FIG. 1 , only one die coater 110 is shown, coating only a first side of metal foil web material 101. It may be preferable for the metal foil web material 101 to subsequently pass through a second die coater to coat a second, opposite side of the metal foil web material, thereby producing an electrode web provided with active material layers on both sides of the metal foil web material (not shown). Downstream of the die coater 110 or die, one or more separators may be provided (not shown) for cutting individual sheets in the electrode web 102. Such separators may be operable to produce individual electrode sheets for use in batteries.

[0102] The assembly 100 includes a conveyor 120 for the active material slurry prepared in the mixer 130. The conveyor 120 takes the active material slurry from the mixer 130 to the die coater 110, where the slurry is dispensed onto the metal foil web material 101 to produce the active material layer 103 that coats the electrode web 102. The mixer 130 is supplied with a predetermined amount of active material powder by a check scale 150 or other dosing device. The mixer 130 can also include one or more ports 140 for additional materials included in the active material slurry. The ports 140 can be provided for introducing active material residue extracted from other assemblies. The ports 140 can be provided for introducing one or more liquid components, such as a binder or a solvent.

[0103] The conveyor 160, which may be a vacuum conveyor, is provided between the hopper 170 and the check scale 150. The hopper 170 may contain the active material powder or a dry mixture of the active material powder and the active material residue powder. The hopper 170 may implement or be coupled to a stationary tank 180 for the active material powder or the dry mixture of the active material powder and the active material residue powder.

[0104] The assembly 100 may include a T-valve (not shown). The T-valve may be disposed on the conveyor 160 between the stationary tank 180 and the die coater 110. Preferably, the T-valve may be disposed below the stationary tank 180, particularly at the lower end of a hopper 170 provided in the stationary tank 180. The T-valve may have an outlet to which a conduit can be attached. The T-valve may be operated to either close the outlet, providing a connection between the stationary tank 180 and the die coater 110 via the conveyor 160, or open the outlet, allowing active material residue to be extracted from the assembly 100, particularly the stationary tank 180, through the outlet.

[0105] 2 shows a system 1 for extracting active material residue coupled to a subsystem of assembly 100 including a hopper 170 and a conveyor 160 attached to the hopper. When system 1 is attached to assembly 100, the assembly is in an extraction mode in which system 1 can be used to remove active material (powder) residue from assembly 100 or a subassembly thereof.

[0106] System 1 shown in FIG. 2 includes mobile tank 3, conduit 5, and pumping device 7. Conduit 5 is attached to mobile tank 3 and connected to hopper 170 via conveyor 160 of assembly 100. Pumping device 7 is securely attached to mobile tank 3. Pumping device 7 of system 1 can be activated to generate negative pressure to suck active material residue from assembly 100, particularly a subsystem or subassembly including hopper 170. As shown in FIG. 2, system 1 can include storage container 9, which can be a reused delivery bag that may have previously been used to provide raw active material powder to assembly 100. Storage container 9 can be connected to mobile tank 3 to contain active material residue extracted by system 1.

[0107] The system 1 may include a carriage or rack 2 including rollers or wheels 21 provided to enable movement of the system 1, including the mobile tank 3, in one or more assemblies 100 on a manufacturing site. The mobile tank 3 is fixedly attached to the rack 2. A pumping device 7 is fixedly attached to the rack 2 and / or the mobile tank 3. A conduit 5 may be, and preferably is, attached to the mobile tank 3 and thus to the rack 2. A pneumatic supply line 4 may be attached to the rack 2.

[0108] 3 shows an exemplary embodiment of a system 1 for extracting active material residues. The mobile tank 3 includes a funnel portion 31 that tapers downward to provide the mobile tank 3 with a large volume, and a cylinder portion 32 above the funnel portion 31. A lid 36 is located directly on top of the cylinder portion 32. A conduit 5 is attached to the mobile tank 3. The attachment of the conduit 5 to the mobile tank 3 is located below the lid 36. The attachment of the conduit 5 to the mobile tank 3 is at the circumferential wall of the cylinder portion 32. The conduit 5 can be a flexible hose.

[0109] A control valve 35 is provided at the junction of the conduit 5 and the mobile tank 3. The control valve 35 can be actuated to close in order to seal the mobile tank 3 from the conduit 5 and the assembly 100 attachable to said conduit. The control valve 35 can be actuated to open in order to establish a fluid connection between the mobile tank 3 and the conduit 5, in particular to establish a fluid connection between the system 1 and the assembly for coating the electrodes with a layer of active material.

[0110] System 1 may be provided with a pneumatic supply line 4 for powering and / or controlling one or more components of the system, such as, for example, pumping device 7. One or more components of system 1 may be coupled to pneumatic supply line 4, such as, for example, control valve 35, exhaust valve 33, vibrator 77, and flow degger 78.

[0111] System 1 is provided with a storage container 9 that is removably attached to mobile tank 3. Storage container 9 can be attached to the bottom of mobile tank 3 to contain active material residue in mobile tank 3 using gravity. A vibrator 77 and / or fluid degger 78 can be provided to improve drainage of active material residue from mobile tank 3 to the storage container. During extraction mode, vibrator 77 and / or fluid degger 78 can be turned off. Vibrator 77 and / or fluid degger 78 can each include a respective drive, such as a pneumatic drive, powered via pneumatic supply line 4 of the assembly.

[0112] The funnel 31 of the mobile tank 3 tapers towards the discharge opening to which the storage container 9 is attached. The storage container 9 can be sealingly attached to the mobile tank 3, for example using a cuff 39, to prevent the escape of active material residues during discharge. The mobile tank 3 has a discharge valve 33 arranged at the discharge hole. The discharge valve can be closed, for example, to allow the storage container 9 to be removed or replaced and / or to seal and close the mobile tank 3 during extraction mode.

[0113] The pumping device 7 is securely attached to the top of the mobile tank 3. The pumping device 7 is attached to the lid 36. In the currently shown embodiment, the pumping device 7 includes a vacuum conveyor 71 that uses a vacuum pump. A filter 73 is positioned between the mobile tank 3 and the vacuum conveyor 71 to protect the pumping device 7 from active material residue powder or other particles. The system, and preferably the pumping device of the system, may further include a dust collector 75 positioned at the exhaust port of the vacuum device to protect the environment from dust particles that are processed by the vacuum pump or the like.

[0114] System 1 is provided with a control panel 10 having a user interface for operator interaction. System 1 includes a controller 11 operatively coupled to one or more components of the system. Controller 11 is coupled to control panel 10 and can turn system 1 on or off and optionally control one or more operating parameters of the system, such as the vacuum, mass flow rate, and / or volume flow rate of pumping device 7. Alternatively or additionally, controller 11 can be coupled to one or more sensors of system 1, such as pressure sensors associated with pneumatic supply line 4, vibrator 77, flow degg 78, and / or pumping device 7.

[0115] 4 shows another exemplary embodiment of a system 1 for extracting active material residues. The mobile tank 3 has a lid 36 directly above the funnel 31. [Explanation of symbols]

[0116] 1: System 2: Rack 3: Mobile tank 4: Air pressure supply line 5: Conduit 7: Pumping device 9: Storage container 10: Control panel 11: Control device 21: Ring 31: Funnel part 32: Cylinder section 33: Exhaust valve 35: Control valve 36: Lid 39: Cuff 71: Vacuum conveyor 73: Filter 75: Dust collector 77: Vibrator 78: Fluid Degger 100: Assembly 101: Metal foil web material 102: Electrode web 103: Active material layer 110: Die coater 120: Conveyor 130: Mixer 140:Port 150: Check scale 160: Conveyor 170: Hopper 180: Fixed tank

Claims

1. 1. A system for extracting active material residues from an assembly for coating an electrode with an active material layer, comprising: a mobile tank configured to store the active material residue; a conduit attachable to the mobile tank and removably connected to the assembly; a pumping device configured to apply a negative pressure to the mobile tank to draw the active material residue from the assembly through the conduit.

2. The system of claim 1 , wherein the pumping device is located in the mobile tank.

3. The system of claim 1 or 2, further comprising a storage container attachable to and detachable from the mobile tank and configured to contain and store the active material residue.

4. 4. The system of claim 1, wherein the mobile tank includes a funnel and / or a drain valve on a lower side of the mobile tank.

5. 5. The system of claim 1, wherein the mobile tank includes a vibrator and / or a fluid degger configured to facilitate evacuation of the active material residue from the mobile tank.

6. 6. The system of claim 1, further comprising a filter between the pumping device and the mobile tank.

7. The system of claim 1 , wherein the conduit is configured for direct connection to a stationary tank, hopper, scale, mixer, and / or die coater of the assembly.

8. 1. An assembly for coating an electrode with an active material layer, comprising: a stationary tank configured to store an active material supply for processing in said assembly; a die coater configured to dispense active material onto a metal foil web material to form the active material layer; a conveyor configured to transfer the active material from the stationary tank to the die coater; an outlet portion configured to selectively open and close an outlet for discharging the active material from the assembly; An assembly wherein a system for extracting active material residue from said assembly is removably attached or attachable to said outlet portion.

9. The outlet portion is a closed state in which the active material flows freely from the stationary tank to the die coater and the active material is restricted from exiting the assembly through the outlet; 9. The assembly of claim 8, wherein the outlet is in fluid communication with the stationary tank such that the active material can exit the assembly through the outlet.

10. 10. The assembly of claim 8 or 9, wherein the outlet comprises a T-piece.

11. 1. A method for extracting active material residues from an assembly for coating an electrode with an active material layer, comprising: providing a mobile tank; attaching a conduit to the mobile tank; connecting the conduit to the assembly; and sucking active material residue from the assembly through the conduit into the mobile tank.

12. 12. The method of claim 11, further comprising the step of opening a selectively closable outlet of the assembly to allow active material residue from the assembly to travel to the mobile tank through an outlet of the outlet.

13. A method for producing an electrode by coating said electrode with an active material layer in an assembly using a mixture of active material and active material residue.

14. The method of claim 13, comprising providing the mixture comprising 0.01% to 25% by weight of the active material residue.

15. A method for manufacturing a battery using a mixture of active material and active material residue.

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