Current collector for rechargeable battery

Abstract

The present invention provides an electrode comprising a current collector in the form of a reinforced metal foil having fine and uniform corrugations that enhance the functional porosity of the foil. Electrodes as current collectors with enhanced metal foils that exhibit high functional porosity of the present disclosure may be used in a number of applications including, but not limited to, lithium ion batteries and power devices using the same to obtain energy.

Description

[0001] Related Applications

[0002] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 267,543, filed on February 3, 2022, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present invention, in some embodiments thereof, relates to electrochemical cells and, more particularly, but not exclusively, to current collectors suitable for use in primary and secondary cells. Background Art

[0004] Recently, a major century-long change from engine to battery has occurred in the automotive and renewable energy industries. Lithium-ion batteries (LIBs) have played a central role as a power source, and post-LIBs have attracted great interest as an alternative to LIBs. There is a strong demand for the rapid development of LIBs and post-LIBs with high performance parameters such as high charge and discharge cyclability, high energy density, high rate performance, and high safety of batteries. Efforts to meet the needs of high-performance LIBs have led to the development of many materials involving anodes, cathodes, separators, and solid electrolytes, which play an important role in improving battery performance. On the other hand, in order to improve battery performance, binders for binding anode and cathode active material particles, conductive additives mixed in the anode and cathode layers, additives added to the electrolyte solution, and current collectors (CCs) are also required. Binders, additives, and CCs with improved compatibility with high-performance anode, cathode, separator, and electrolyte materials can enable high-performance anodes, cathodes, separators, and electrolytes to be achieved.

[0005] CC plays an important role in the charge and discharge process of the battery. CC supports the active material layers of the anode and cathode, and they collect and distribute electrons to / from the supported active layers. In order to accelerate the transfer of electrons to / from the active layers, the contact between CC and the active layers should be maintained for thousands of cycles during the charge / discharge process. The active layer should have a path where fast electron transport is spread throughout the active layer, and Li + A structure in which ions can diffuse easily into the active layer. The CC structure should be designed to maintain the functionality of the active layer structure. Currently, in commercially available LIBs, the CC has a thickness of 10–12 μm and is planar. Copper (Cu) and aluminum (Al) foils are used as CCs for the anode and cathode, respectively. In the anode and cathode, Li + Ions and electrons should quickly move to and from the anode and cathode particle surfaces to charge and discharge the battery at high current density, respectively. Therefore, in the anode and cathode layers, Li +In the present LIB preparation process, a slurry consisting of anode or cathode active material particles, a binder, a conductive additive and a solvent is cast on a planar CC surface, and then the solvent in the slurry is evaporated to dry the anode and cathode layers formed on the CC. Anode and cathode material particles are filled into the prepared anode and cathode layers. Binders and conductive additives are located in the spaces between active material particles to bind the particles and form electrical contacts between active material particles. Li + An electrolyte solution of ions permeates through the space. + Ions pass through the space permeated by the electrolyte solution and reach the surface of the anode and cathode active material particles. In order to improve battery performance, Li + and improved paths for electrons. In addition, CCs should have high mechanical strength, chemical and electrochemical stability, and adhesion between the active material layer and the CC surface. In order to achieve these requirements, optimization of materials for CCs, structural modification of CCs, and formation of surface layers on CCs have been conducted. Improvements in battery performance such as charge / discharge capacity, energy density, and capacity retention at high current density and its stability can be obtained through the contribution of these factors.

[0006] Three-dimensional (3D) current collectors have been shown to be promising by enabling high energy density and high power density batteries. The utilization of 3D current collectors in lithium-based batteries benefits from the conductivity of the interconnected 3D structure, which ensures that electrons and lithium ions can be quickly transported / diffused throughout the network, and from the mechanical strength and chemical stability obtained through the microstructure, preventing delamination of active materials and collapse or corrosion of the skeleton, while maintaining flexibility and large pore volume, which can ensure sufficient space to accommodate the volume expansion of active materials. Despite the many advantages of 3D current collectors, there are still some concerns that need to be addressed: 1) The large surface area usually leads to a high electrode / electrolyte interface area, resulting in a large consumption of electrolyte and lithium materials, thereby leading to low Coulombic efficiency; 2) 3D porous current collectors still retain a considerable volume due to their disordered microstructure and low packing density, and their volumetric capacity is incomparable to those densely packed materials; 3) The high stability requirements of battery systems require strict control of the structure of 3D current collectors; and 4) Due to the complexity of 3D current collector synthesis, large-scale 3D current collectors for practical applications are still economically out of reach; 5) Since in industry the active materials are coated on metal foils through a roll-to-roll process and the current collectors need to be welded to metal leads, small or monolithic 3D current collectors are incompatible with downstream manufacturing processes.

[0007] Nakamura, T. et al. ["Electrochemical performance of cathodes prepared on current collector with different surface morphologies", J. Power Sources, 2013, 244, 532-537] reported cathode electrodes prepared on aluminum current collectors with different surface morphologies by conventional scraper technology, and their electrochemical performance, especially at high current rates, which was affected by the surface morphology of the current collector.

[0008] Wang, GQ et al. [“Investigation of the hole-formation process during double-sided through-maske electrochemical machining”, J. Mat. Processing Technology, 2016, 234, 95-101] reported a through-mask electrochemical machining technology developed for making hole arrays in titanium alloys that are difficult to cut using traditional machining.

[0009] Jeong, CU et al. [“Embossed aluminum as a current collector for high-rate lithium cathode performance,” J. Power Sources, 2018, 398, 193–200] reported an aluminum foil prepared by an anodization process followed by chromate phosphate treatment, which was evaluated as a current collector for cathode powders prepared by conventional electrode coating methods.

[0010] Shan, W. et al. [“Three-dimensional Porous Current Collector for Lithium Storage Enhancement of NiO Electrode”, Acta Chim. Sinica, 2019, 77(6), 551-558] reported the preparation of 3D porous metals, which have been used as current collectors to improve the cycle stability and high rate capacity of lithium-ion batteries.

[0011] Loghavi, MM et al. [“Improvement of the cyclability of Li-ion battery cathode using a chemical-modified current collector”, J. Electroanal. Chem., 2019, 841, 107–110] reported an aluminum current collector treated by a simple reaction of aluminum foil with a solution containing three acids, and studied the physical effects of this modification on the current collector surface by scanning electron microscopy (SEM) and contact angle testing.

[0012] Choi H. et al. ["Fabrication of a Porous Copper Current Collector Using a FacileChemical Etching to Alleviate Degradation of a Silicon-Dominant Li-ionBattery Anode", Corrosion Science and Technology, 2021, 20(5), 249-255] reported a simple method for preparing a three-dimensional porous copper current collector (3D Cu CC) for silicon-dominated anodes in lithium-ion batteries (LiB). The 3D Cu CC is prepared by combining chemical etching and thermal reduction from a planar copper foil.

[0013] WO2010116872A1 teaches a method for manufacturing an electrode for an electricity storage device, which prevents electrode particles from breaking and current collectors from bending, and forms a plurality of grooves in one direction on the surface of the current collector.

[0014] WO2013157806A1 relates to a method for manufacturing an electrode for a secondary battery, the method comprising a step of surface treating a current collector so as to provide a morphology having a surface roughness (Ra) between 0.001 μm and 10 μm on the entire surface and to improve adhesion between an electrode active material and the current collector, and an electrode for a secondary battery manufactured by using the method.

[0015] WO2010011509A3 teaches an electrode material comprising: a first electrode; and a current collector constructed adjacent to and bonded to the first electrode, wherein the current collector comprises a plurality of conductive protrusions extending from the current collector into the first electrode along the z-direction.

[0016] CN206250289U is a utility model that proposes a current collector, which is formed with a surface embossed portion in the thickness direction, wherein the embossed portion is distributed with a plurality of embossments, and inside each embossed periphery, a groove extending from the current collector surface to the current collector along the thickness direction of the current collector is formed in the peripheral area along the thickness direction of the current collector.

[0017] JP2002216775A teaches a method of forming a current collector foil for secondary battery electrodes in which a large number of through holes are formed, wherein a non-elongated embossed roll having a large number of protrusions and a flat roll having no unevenness are provided.

[0018] US20160197353A1 provides a perforated plate-like material having at least one through hole extending from a first main surface to a second main surface opposite thereto, and in its cross-sectional shape, it has a minimum width portion on the hole surface, and has a first main surface portion where the hole surface terminates at the first main surface, and includes a first protruding curve portion between the first main surface portion and the minimum width portion, and at least a portion of the first protruding curve portion has the surface properties / shape of a non-hole surface on the first main surface. Summary of the invention

[0019] The present invention provides a foil having fine uniform functional porosity that can be produced inexpensively in a roll-to-roll configuration, and the porosity originates from the corrugation and / or perforation of the foil. The enhanced metal foils of the present disclosure can be used in many applications, including but not limited to use as current collectors in lithium-ion batteries. The present invention provides enhanced metal foils that benefit from the advantages of carefully produced 3D metal structures, but are not limited by the cost, time and production size associated with state-of-the-art metal processing methods. The functional porosity of thin metal foils is increased to levels that challenge 3D structures (such as metal foams) through unique corrugation and perforation criteria and methods described below, while maintaining and benefiting from the speed, cost and roll readiness of thin foil production methods.

[0020] Modern current collector design faces several challenges, including:

[0021] The resistance of the current collector is reduced to improve the efficiency of the device; this is achieved by the present invention teaching the use of materials with low resistance such as copper, aluminum or nickel, and by designing the current collector to have a low resistance path for the current to flow.

[0022] The surface area of ​​the current collector is increased to improve its ability to collect electrical current; this is accomplished by the present invention, for example, by adding surface features such as vias, protrusions, and / or ridges.

[0023] Minimize the cost of the current collector; the present invention achieves this by teaching the use of low cost materials and by simplifying the production and design of the current collector to reduce manufacturing costs.

[0024] Ensuring that the current collector is compatible with other materials and techniques commonly used in an industrial setting; this is achieved through the inventive approach by teaching a continuous production method that provides a current collector that is not limited in size (length) and therefore facilitates a roll-to-roll coating process.

[0025] The present invention relates to an object comprising a metal component characterized by a seamless repeating pattern of through-hole textural elements and at least one of: (a) a seamless repeating pattern of non-perforated textural elements; (b) a local thickness in the range of 3-100 μm; and (c) a functional porosity (P) of at least 10%. f ), wherein the metal member is at least 0.1 m wide and at least 0.5 m long. The metal member can be composed of various metals, including aluminum, copper, nickel, gold, cobalt, iron, titanium, steel, stainless steel and any alloys and combinations thereof. The object can be used as a current collector in a battery electrode. The present invention also relates to a roll comprising a cylindrical core and an object wound around the core, and the object wound into a roll can have any length up to several thousand meters.

[0026] Thus, according to an aspect of some embodiments of the present invention, there is provided an electrode comprising at least one current collector, the current collector comprising at least one metal component, wherein the metal component is characterized in that:

[0027] seamless repeating pattern of non-perforated structural elements;

[0028] Local thickness in the range of 3-100 μm; and

[0029] Functional porosity (Pf) of at least 10%.

[0030] In some embodiments, the non-perforated structural elements are selected from individual elements and extended elements.

[0031] In some embodiments, the non-perforated structural elements in the seamless repeating pattern have an average size in the range of 10-500 μm.

[0032] In some embodiments, the horizontal distance between the non-perforated structural elements is less than 1,000 μm.

[0033] In some embodiments, the seamless repeating pattern is characterized by a uniformity of at least 15%.

[0034] In some embodiments, the metal component comprises a metal selected from the group consisting of aluminum, copper, nickel, gold, cobalt, iron, titanium, steel, stainless steel, and any alloys and combinations thereof.

[0035] In some embodiments, the local thickness is in the range of 3-20 μm.

[0036] In some embodiments, a ratio between a minimum bounding box of the metal component and the local thickness is in the range of 1.1-5.

[0037] In some embodiments, the functional porosity is at least 50%.

[0038] In some embodiments, the metal component is characterized by a tensile strength of at least 20-45 MPa.

[0039] In some embodiments, the electrode is characterized by:

[0040] The metal member comprises copper,

[0041] The seamless repeating pattern of the non-perforated structural elements comprises primitives of circular depressions and / or circular protrusions each having a diameter of less than 500 μm and a horizontal distance of less than 1000 μm,

[0042] The local thickness is less than 50 μm, and

[0043] The functional porosity (P f ) is at least 50%.

[0044] In some embodiments, the electrode is characterized by:

[0045] The metal member comprises aluminum,

[0046] The seamless repeating pattern of the non-perforated structural elements comprises primitives of circular depressions and / or circular protrusions each having a diameter of less than 500 μm and a horizontal distance of less than 1000 μm,

[0047] The local thickness is less than 100 μm, and

[0048] The functional porosity (P f ) is at least 50%.

[0049] According to another aspect of some embodiments of the present invention, there is provided a battery comprising at least one electrode provided herein.

[0050] According to another aspect of some embodiments of the present invention, there is provided an electric device comprising at least one battery provided herein.

[0051] In some embodiments, the electric device is selected from an electric vehicle for transportation in air, land, water, and / or space, a smartphone, a laptop computer, a media player, a power tool, a toy, a heating device, a cooling device, and a lighting device.

[0052] As used herein, the term "about" refers to ±10%. For example, "about 100 μm" includes 100 μm and 90 μm, 91 μm, 92 μm, 93 μm, 94 μm, 95 μm, 96 μm, 97 μm, 98 μm, 98 μm, 99 μm, 100 μm, 101 μm, 102 μm, 103 μm, 104 μm, 105 μm, 106 μm, 107 μm, 108 μm, 109 μm and 110 μm.

[0053] The terms "including", "comprising", "having" and their conjugations mean "including but not limited to".

[0054] The term "consisting of" means "including and limited to."

[0055] The term "consisting essentially of" means that the composition, method or structure may include additional ingredients, steps and / or parts, but only if the additional ingredients, steps or parts do not materially change the basic and novel characteristics of the claimed composition, method or structure.

[0056] As used herein, the phrase "selected from" includes all members of the recited group, each member of the recited group, and all possible combinations. For example, selected from A, B, and C includes only A, and only B, and only C, and A and B, and A and C, and B and C, and A, B, and C.

[0057] As used herein, the phrases "substantially free" and / or "essentially free" in the context of a substance refer to a composition that is completely free of such a substance or contains less than about 5%, 1%, 0.5% or 0.1% of the substance by total weight or volume of the composition. Alternatively, in the context of a process, method, property or feature, the phrases "substantially free" and / or "essentially free" refer to a process, composition, structure or article that is completely free of a process / method step or a property or a feature, or a process / method in which a process or method step is performed at less than about 5%, 1%, 0.5% or 0.1% compared to a given standard process / method, or a property or feature characterized by less than about 5%, 1%, 0.5 or 0.1% of a property or feature compared to a given standard.

[0058] As used herein, the term "substantially maintain" when applied to an original, desired, or provided property of an object or composition means that the property does not change by more than 20%, 10%, or 5% in the processed object or composition.

[0059] The term “exemplary” is used herein to mean “serving as an example, instance, or illustration.” Any implementation described as “exemplary” is not necessarily to be construed as preferred or advantageous over other implementations and / or to exclude the incorporation of features from other implementations.

[0060] The words “optionally” or “optionally” are used herein to mean “provided in some embodiments and not provided in other embodiments.” Unless such features are in conflict, any particular embodiment of the present invention may include a number of “optional” features.

[0061] When used herein, references without a specific number include plural referents unless the context clearly dictates otherwise. For example, the term "a compound" or "at least one compound" may include a plurality of compounds, including mixtures thereof.

[0062] Throughout this application, various embodiments of the present invention may be presented in a range format. It should be understood that the description of the range format is only for convenience and brevity and should not be interpreted as a hard limit to the scope of the present invention. Therefore, the description of the range should be considered to have specifically disclosed all possible sub-ranges and individual numerical values ​​within the range. For example, the description of a range such as 1 to 6 should be considered to have specifically disclosed sub-ranges such as 1 to 3, 1 to 4, 1 to 5, 2 to 4, 2 to 6, 3 to 6, etc., and individual numbers such as 1, 2, 3, 4, 5 and 6 within the range. This applies regardless of the breadth of the range.

[0063] Whenever a numerical range is indicated herein, it is meant to include any cited numeral (fractional or integer) within the indicated range. The phrases "range between a first indicated numeral and a second indicated numeral" and "range from a first indicated numeral to a second indicated numeral" are used interchangeably herein and are meant to include the first and second indicated numerals and all fractions and integers therebetween.

[0064] The terms "process" and "method" as used herein refer to ways, means, techniques and procedures for accomplishing a given task, including but not limited to those ways, means, techniques and procedures that are known or readily developable from known ways, means, techniques and procedures by practitioners in the chemical, material, mechanical, computing and digital fields.

[0065] Unless otherwise defined, all technical and / or scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art to which the invention belongs. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present invention, exemplary methods and / or materials are described below. In the event of a conflict, the present patent specification, including definitions, shall prevail. In addition, the materials, methods, and examples are illustrative only and are not necessarily limiting. BRIEF DESCRIPTION OF THE DRAWINGS

[0066] Some embodiments of the present invention are described herein with reference to the accompanying drawings by way of example only. With specific and detailed reference now to the drawings, it should be emphasized that the details shown are merely examples and are used for illustrative discussion of embodiments of the present invention. In this regard, the description in conjunction with the drawings makes it clear to those skilled in the art how embodiments of the present invention can be practiced.

[0067] In said drawings:

[0068] Figure 1A -E shows an exemplary primitive (tile) and its corresponding seamless repeating pattern;

[0069] Figure 2 A simplified illustration showing the concepts of local thickness, minimum bounding box (MBB) thickness, and functional porosity;

[0070] Figure 3 Nine non-limiting examples of seamless repeating patterns provided by wrinkle enhancement according to some embodiments of the present invention are shown;

[0071] Figure 4 shows a schematic diagram of an exemplary corrugated metal component exhibiting SRP of circular depressions and protrusions provided by corrugation reinforcement using separate non-perforated structural elements, and showing the local thickness and bounding box thickness of the exemplary component, according to some embodiments of the present invention;

[0072] Figure 5A -C shows a schematic diagram of a coating scheme for a reinforced metal foil according to some embodiments of the present invention, wherein the top cross-sectional view ( Figure 5A ) shows an electrode which exhibits the same thickness as the total thickness of the corrugated foil member (MBB thickness), similar to the middle figure ( Figure 5B ), bottom graph( Figure 5C ) shows an electrode exhibiting a greater thickness compared to the total thickness of the corrugated member (MBB thickness);

[0073] Fig. 6A-B shows a micrograph taken using an optical microscope, taking a photo of a 12 μm thick copper foil ( Fig. 6A ) and 60μm thick aluminum foil ( Figure 6B ) each foil having undergone corrugation reinforcement in the form of hexagonally arranged circular depressions spaced about 500 μm horizontally from one another;

[0074] Figure 7 shows a photograph taken with a Leica DVM6 optical microscope of a dried layer of a slurry applied to a corrugated aluminum foil or component after aluminum removal by acid etching, showing five raised structural elements and four recessed structural elements pointing to opposite sides, according to some embodiments of the present invention;

[0075] Figure 8 An SEM micrograph of a wrinkled copper mesh is shown, showing a top view of a copper current collector coated with active material on one side for demonstration purposes;

[0076] Fig.9A -B shows battery cycling results obtained for lithium-ion batteries including wrinkled current collectors according to some embodiments of the present invention, wherein Fig.9A Shown are the measurements of the retained capacity (capacity scale is a percentage of the initial capacity) of cells using the corrugated CC configuration provided herein, Fig. 9B The measured values ​​of the internal resistance of the battery at various states of charge are shown, while the results are compared with those obtained for similar batteries containing conventional (flat, non-porous) current collectors;

[0077] Fig. 10A -B shows a photograph of a reinforced metal foil (metal member) according to some embodiments of the present invention, the foil comprising aluminum and exhibiting corrugation reinforcement, wherein the local thickness is about 20 μm, the vertical distance (height) of the circular protrusions (non-perforated structural elements) is about 72 μm (which is also the MBB thickness), and the horizontal distance between the structural elements is about 500 μm, wherein Fig. 10A and a close-up inset showing the entire roll of reinforced metal foil, Fig. 10B A microscopic image showing corrugated structural elements is shown in FIG; and

[0078] Fig.11A -C shows a photograph of a reinforced copper foil according to some embodiments of the present invention, which exhibits wrinkling reinforcement, wherein the local thickness is about 12 μm, the MBB thickness is about 100 μm, and the horizontal distance between structural elements is about 500 μm, wherein Fig.11A The entire roll of reinforced metal foil is shown in Fig. 11B A close-up inset is shown in FIG. Fig. 11C A microscopic image showing corrugated structural elements is shown in . DETAILED DESCRIPTION

[0079] The present invention, in some embodiments thereof, relates to electrochemical cells and, more particularly, but not exclusively, to current collectors suitable for use in primary and secondary cells.

[0080] Before explaining at least one embodiment of the invention in detail, it should be understood that the invention is not necessarily limited in its application to the details set forth in the following description or exemplified by the examples. The disclosure is intended to encompass other embodiments or to be practiced or carried out in various ways.

[0081] As discussed above, the current collector is responsible for making electrical contact with the anode and cathode in a rechargeable battery so that electrons can be transferred to the battery in the form of charge-balancing ions or lithium ions (Li + ) (especially in the case of lithium and lithium-ion batteries) enter and leave the battery. + When entering the cathode, electrons must also enter the cathode to balance the charge of the cathode. + The electrons are conducted through an electrolyte that does not conduct electrons, so they need another way to get to and from the cathode and anode. The current collector (CC) provides this path. An external circuit (the "load", such as a light bulb or an electric vehicle) is connected to the rechargeable battery through terminals that are in electrical contact with the CC.

[0082] Commercially available primary and secondary batteries traditionally use planar, flat metal foils, woven metals or meshes attached to the back of the cathode and anode as their CCs. These CCs are limited in their ability to support large amounts of active materials, and their ability to uniformly transfer charge from the active material mass and extract useful energy from large active material loads is also limited. Lack of uniformity and other spatial inconsistencies are the main causes of battery malfunctions, failures and even dangerous outcomes, mostly due to delamination of active materials from the CC, formation of hot spots, cracks and expansion.

[0083] When conceiving the present invention, the inventors envisioned a CC for battery electrodes that could be manufactured according to industry requirements, standards, practices and machines, i.e., coated and integrated into battery production lines, and that, unlike other 3D CCs, could be manufactured quickly and in any length (rolls of tens, hundreds and thousands of meters in length) at a cost comparable to standard metal foils of similar size / quality.

[0084] The inventors have contemplated that corrugation can increase the surface area of ​​a thin metal foil because the corrugated foil presents a wavy / uneven structure with a series of ridges and grooves, which increases the overall surface area of ​​the foil compared to a flat foil of the same size because the wavy / uneven structure creates more surface area for contact with the active material. It has also been contemplated that the increased surface area in the structural material will be beneficial because it can increase the bonding surface area between the foil and other materials.

[0085] While putting the present invention into practice, the inventors demonstrated an enhanced metal foil having structural elements that increase its surface area and minimum bounding box voids (see below, functional porosity), such that the amount of active material that can be loaded thereon is much greater than a flat featureless metal foil of similar size / mass. The structural elements of the enhanced metal foil also shorten the electrical paths within the active material layer deposited thereon, thereby improving the contact and charge transfer parameters of using such enhanced metal foil as an electrode of a CC.

[0086] Thus, described herein are reinforced metal foils useful as current collectors in electrodes that overcome the above-mentioned disadvantages and solve some of the problems in the related art to which the present disclosure pertains, as well as methods of making and using the same.

[0087] Thus, according to some embodiments of the present invention, there is provided an electrode comprising at least one current collector comprising at least one metal member referred to herein as a reinforcing metal foil, characterized by a combination of some or all of the following characteristics:

[0088] Made of conductive material (preferably metal);

[0089] exhibiting seamless repeating patterns of non-perforated structural elements;

[0090] exhibiting a local thickness of less than 100 μm or a local thickness in the range of 3-100 μm; and

[0091] Functional porosity of at least 10% or greater than 50%.

[0092] Reinforced Metal Foil:

[0093] As used herein, the terms "enhanced" and "enhancement" refer to improvements in certain properties of a foil-like object as compared to those properties in a comparable original metal foil or unreinforced foil, wherein the original foil and the enhanced foil are each related to the context of an object used as a current collector in an electrode, regardless of the process by which they are obtained. Depending on the embodiment, the term "enhancement" encompasses the terms "extend", "extend", "expand", "stretch", "enlarge", "swell", "enlarge", "enlarge", "broaden", "enlarge", "expand", "stretch", "refine", "lengthen", "unfold", "stretch", "widen", and "inflate".

[0094] One of the objects of the present invention is to provide a reinforced metal foil which can be effectively used in an industrial environment, in particular as a current collector forming an electrode for the battery industry. The phrase "reinforced metal foil" is used interchangeably with the term "member" and the term "object" and refers to the final product, regardless of the process by which it is obtained, i.e. the term "reinforced" is used as a pronoun rather than a verb and does not necessarily mean that the original foil is a precursor to the final product.

[0095] In the context of embodiments of the present invention, a raw metal foil is a very thin sheet of metal, typically made by rolling, hammering and / or electrochemical deposition. Here and throughout, the term "raw" is used to refer to an unreinforced foil, or, according to some embodiments of the present invention, to a precursor substrate of a component provided herein, or, according to some embodiments of the present invention, to a step in a method of making the metal component. In some embodiments, the term "raw metal foil" refers to a flat, smooth and planar metal foil or a non-reinforced metal foil.

[0096] In some embodiments, the reinforced metal foil (object; member) is made of a conductive metal. In some embodiments, the object comprises or consists of aluminum, copper, nickel, magnesium, cobalt, iron, titanium, platinum, tungsten and gold and any alloys thereof (including steel, stainless steel, carbide / nitride steel, bronze, silver-gold alloy, tin wax, brass and pig iron). In some embodiments, the alloy comprises magnesium, manganese, chromium, molybdenum and vanadium, as well as semi-metallic and / or non-metallic elements.

[0097] As used herein, the term "thickness" refers to the local thickness of the original foil or the thickness of a non-corrugated member, or the thickness achieved by reinforcement of the foil according to some embodiments of the present invention.

[0098] In some embodiments, the object (metal component) is a corrugated foil, and its local thickness refers to the property of the flat original foil that has undergone corrugation, rather than the thickness of the corrugated foil. Unless otherwise explicitly stated, the thickness of the corrugated object is the thickness of the smallest bounding box corresponding to the enhanced object as described below.

[0099] In some embodiments of the present invention, the local thickness of the components provided herein is as thin as about 3 micrometers (μm), and typically the local thickness of the components is less than about 100 μm, less than 90 μm, less than 80 μm, less than 70 μm, less than 60 μm, less than 50 μm, less than 40 μm, less than 30 μm, less than 20 μm, less than 15 μm, less than 10 μm, less than 9 μm, less than 8 μm, less than 7 μm, less than 6 μm, less than 5 μm or less than 4 μm. In some embodiments, the local thickness of the member is about 3 micrometers (μm), 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, about 10 μm, 15 μm, 20 μm, 30 μm, 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, about 100 μm, 110 μm, 120 μm, 130 μm, 140 μm, 150 μm, 160 μm, 170 μm, about 180 μm, about 200 μm, about 250 μm, about 260 μm, about 270 μm, about 280 μm, about 290 μm, about 300 μm, about 350 μm, about 360 μm, about 370 μm, about 380 μm, about 390 μm, about 400 μm, about 450 μm, about 460 μm, about 470 μm In some embodiments of the present invention, the thickness of the metal foil forming the basis of the member is within a certain range. In some embodiments of the invention, the local thickness of the member is in the range of 3-100 μm, 4-50 μm, 4-40 μm, 4-30 μm, 4-20 μm, or 4-10 μm 10-50 μm, 40-100 μm, 90-200 μm, 190-300 μm or 290-400 μm.

[0100] In some embodiments, the reinforced metal foil is a corrugated reinforced metal foil. In some embodiments, the reinforced metal foil is a metal mesh reinforced by corrugation.

[0101] In some embodiments, the metal is aluminum and the local thickness of the metal member is in the range of about 3-250 μm, 3-100 μm, 3-50 μm, 4-500 μm, 10-50 μm, 50-100 μm, or in the range of about 100-250 μm. According to some embodiments of the present invention, the thickness of a smooth (flat, non-corrugated) member made of aluminum, or the local thickness of a member made of aluminum corrugated but not perforated by a seamless repeating pattern (SRP) of non-perforated structural elements, or the local thickness of a member made of aluminum mesh and mesh corrugated with SRP, is less than 100 μm, less than 50 μm, less than 40 μm, less than 30 μm, less than 20 μm, less than 15 μm, less than 10 μm, less than 8 μm, or less than 6 μm.

[0102] In some embodiments, the metal is copper and the local thickness of the metal component is in the range of about 4-250 μm, 4-50 μm, 6-50 μm, or in the range of about 10-100 μm. According to some embodiments of the present invention, the thickness of a smooth (flat, non-corrugated) component made of copper, or the local thickness of a component made of copper corrugated by SRP but not perforated, or the local thickness of a component made of SRP corrugated copper mesh and mesh is less than 100 μm, less than 50 μm, less than 40 μm, less than 30 μm, less than 20 μm, less than 15 μm, less than 10 μm, less than 8 μm, less than 6 μm, or less than 5 μm.

[0103] As described below, the components provided herein are enhanced to increase their functional porosity. The enhanced object may be thicker than its precursor original foil, so in some embodiments including any of the above embodiments, the thickness of the component (see below, MBB thickness) is about 10 μm, about 20 μm, about 30 μm, about 40 μm, about 50 μm, about 60 μm, about 70 μm, about 80 μm, about 90 μm, about 100 μm, about 150 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm or about 1 mm.

[0104] Unless otherwise stated, the local thickness of a component or object provided herein can be measured using microscopy techniques such as scanning electron microscopy (SEM), optical microscopy, a micrometer, or other methods.

[0105] In some embodiments, the metal foil is in the form of a long sheet with a fixed width and an unlimited length, subject only to practical limitations. In some embodiments, the metal foil has a width in the range of 10 cm to 5 meters and a length of at least 0.5 meters, or at least 1 meter, or at least 2 meters, or at least 5 meters, or at least 10 meters.

[0106] In some embodiments of the present invention, the enhanced metal foil provided herein is produced as a single piece or continuous roll using a manual or automatic process. The substrate here can be a metal mesh (i.e., a perforated material), a dense metal layer, a metal foil, etc. The process for enhancing the metal substrate can be carried out at room temperature, or the deformation process can be assisted by heating. The process using heating can be carried out in a standard atmosphere or in an atmosphere with a vacuum or an inert gas.

[0107] After the metal foil substrate is enhanced, the enhanced metal foil (component) can be stacked on top of other components. In some embodiments, the enhanced metal foil is stacked to form a layered structure, and in some embodiments, the stacked components are bonded together. In some embodiments, the bonding is achieved by diffusion bonding. In other embodiments, the bonding is achieved by ultrasonic welding. In other embodiments, the bonding is achieved by welding. In some embodiments, the stacked components are laminated to provide thicker objects. In some embodiments, the thickness of the layer is 1 μm, 5 μm, 10 μm, 25 μm, 50 μm or 100 μm. WO2022064483A1 of the assignee of the present invention teaches a method of liquid cold welding (LCW), comprising: (a) engaging two or more porous conductive substrate layers between perforated non-conductive frames so that the substrate layers are in contact with each other; (b) immersing the substrate layers in an electrolyte solution; and (c) applying current and / or voltage and / or electricity to the electrolyte solution. WO2022064483A1 also discloses a device suitable for performing some embodiments of the method.

[0108] In some embodiments, the components can be stacked on top of other metal substrates that have not been reinforced. In some embodiments, the non-reinforced metal substrates are stacked. In some embodiments, the non-reinforced metal substrates are stacked and bonded together. In some embodiments, the bonding is achieved by diffusion bonding, thermal welding, ultrasonic welding, or electrochemical welding.

[0109] In some embodiments, the member is produced as a single sheet with or without heating. In some embodiments, the member is produced as a continuous sheet with or without heating.

[0110] In some embodiments, the member is manufactured by a continuous process discussed below and wound into a roll. In some embodiments, the member is rolled into a cylindrical roll having a width in the range of 10 cm to 3 meters and a length of at least 10 meters.

[0111] The reinforced metal foil provided herein is designed for continuous manufacture, which generally produces a roll of the object, and is further designed to be used in the form of a roll in an industrial environment. Therefore, the metal component provided herein is characterized by mechanical properties that make it producible and usable in an industrial environment. One of these properties is tensile strength, which is sufficient to withstand the forces and stresses of drawing, winding, stretching and other operations used in the manufacturing process. The tensile strength required for a typical foil used to manufacture a current collector for a battery in a typical industrial environment will vary according to the specific application and the type of foil, coating material and battery. For example, a foil for a lithium ion battery generally has a tensile strength of about 45MPa (about 4.6KgF / mm2 , in kgf / mm2). The enhanced metal foils provided herein differ from the original foils in that the enhanced properties should also withstand the forces and stresses used in industrial environments, and the objects should not tear and their structural elements should be protected. In the context of some embodiments of the present invention, the objects provided herein are characterized by a tensile strength of at least 20-45 MPa, at least 60 MPa, 55 MPa, 50 MPa, 45 MPa, 40 MPa, 35 MPa, 30 MPa, 25 MPa, or at least 20 MPa.

[0112] Seamless Repeating Pattern:

[0113] An object of the present invention is to provide a reinforced metal foil characterized by a high uniformity of its structural elements and properties substantially over its entire area, whereby it is also desirable that the properties of the reinforcement are substantially the same over the entire area of ​​the foil. It is to be noted here that the term "structural elements" refers to the surface quality or feel of a material, such as its roughness, smoothness or pattern. Structural elements are visual aspects of a surface that give it a sense of depth and dimension. In the context of the present invention, the term "structural elements" includes non-perforated elements (protrusions; depressions).

[0114] In order to exhibit uniform reinforcement, the reinforced metal foil provided herein is characterized, inter alia, by a non-random and specially designed seamless repeating pattern (SRP) of structural elements that conceptually spans the entire area of ​​the metal foil with no visible boundaries or irregular / arbitrary / random transitions between or within the repeating pattern primitives. In the context of the present invention, the reinforced metal foil is considered to be an infinite planar area, limited only by practical limits.

[0115] As used herein, the term "patterned" when referring to foil refers to a non-random, specially designed and engineered metal foil having regularly spaced and oriented structural elements on its surface in some embodiments of the present invention. The features may be, but are not limited to, peaks, valleys, defects, bends, twists, undulations, or combinations thereof.

[0116] The phrase "seamless repeating pattern" (abbreviated herein as SRP) as used herein refers to a pattern that spans an undefined and unrestricted surface without visible transitions or boundaries. An SRP is an endlessly repeating pattern of structural elements, consisting of repeating elements such as geometric shapes or decorative designs arranged in a two-dimensional format. An SRP extends infinitely in all directions, creating a seamless visual effect. This pattern type is commonly used in textiles, wallpapers, flooring and other decorative materials, as well as graphic design, packaging and branding. As discussed herein, an SRP can be defined by a repeating pattern unit, and placing multiple such units in close proximity (juxtaposition) to each other will provide the SRP. The repeating unit is referred to herein as a tile or primitive.

[0117] The primitives are defined by one or more structural elements, and each primitive is integrated into adjacent primitives to achieve the SRP. In the context of the present invention, the primitives include structural elements in the form of protrusions / indentations (i.e., protrusions / depressions, bulges / creases, valleys / ridges), and the entire SRP can be defined by the primitives. As explained below, in contrast to the random distribution of similar structural elements over similar areas, the arrangement of any given structural element in the seamless repeating pattern that characterizes the metal components provided herein is not random; therefore, the SRP that characterizes the metal foils provided herein is non-random by definition.

[0118] Covering a planar metal foil surface with the above-described SPR follows essentially any standard tessellation or tiling method using one or more geometric shapes (tiles; primitives) with no overlaps and gaps. Although some embodiments of the present invention are drawn to metal foils (which are essentially two-dimensional entities if thickness is ignored), it is worth noting that tessellation can be generalized to higher dimensions and various geometric shapes. In some embodiments, the SPR is provided by periodic tiling, while some embodiments include regular tiling using regular polygonal tiles, all of which have the same shape, and some embodiments include semi-regular tiling using more than one shape and regular tiles with the same arrangement at each corner.

[0119] The term "element" or "tile" as used herein refers to the smallest and simplest single structural element or a non-repeating group of structural elements, which are repeated to form and define the SRP. In the context of the present invention, the element is closely related to the unit cell in a 3D lattice (crystal / lattice), and the SRP is formed by repeating the element in a plane in any direction on the plane. There may be one structural element or more than one structural element in an element. In some embodiments, the element includes more than one structural element related to each other by symmetry operations (such as translation, rotation and reflection transformation operations) in a 2D plane. In some embodiments, the element includes more than one structural element arranged asymmetrically relative to each other, or more than one structural element with different sizes / shapes. A plane or SRP can be completely tiled (covered) with triangular, rectangular and hexagonal polygons (tiles), each of which has one or more structural elements arranged inside. Rectangular and hexagonal tiles can be placed using the same tile orientation (translation only, no rotation), while triangular tiles are placed with a 60° rotation (translation and rotation).

[0120] An example of a simple primitive is a dot, whose behavior can be convex / concave (wrinkle enhancement), and whose SPR can be a circle packing of squares or hexagons, where the circles are evenly spaced. Further exemplary and non-limiting embodiments of primitives and their corresponding SRPs, according to some embodiments of the present invention, are presented in Figure 1A -E.

[0121] Figure 1A -E shows an exemplary primitive (tile) and its corresponding seamless repeating pattern, where Figure 1A A square primitive (left) is presented, which shows rounded rectangular structural elements of various sizes arranged asymmetrically within a tile, and their corresponding SPRs generated by endlessly repeating the primitive on a plane; Figure 1B Three variations of the square primitive are shown, two with asymmetric arrangements of structural elements and one with a symmetric arrangement (lower left, 4-fold rotation), resulting in the same SPR; Figure 1C Three variations of tile shapes are shown, and the same SPR produced by endlessly repeating the primitive on a plane through translation operations; Figure 1D Four variations of tiles are shown, and the same SPR produced by endlessly repeating the primitive on a plane through rotation and translation operations; Figure 1E Tiles are shown, along with their corresponding SPRs produced by endlessly repeating the primitives on a plane through reflection, rotation, and translation operations.

[0122] It is worth noting that the terms "structural element", "element" / "tile" and "seamless repeating pattern" apply to any type of foil reinforcement, as these terms will be discussed below. In other words, the component is required to present a seamless repeating pattern for any of its structural elements (including recesses / protrusions and / or creases).

[0123] In fact, in some embodiments, the reinforced metal foil exhibits SRP over its entire area from one side to the other before being incorporated into the electrode; in some embodiments, due to technical / practical requirements of industrial processing machinery, the SRP spans the main area of ​​the foil, leaving narrow boundaries along its edges. By boundaries is meant that the metal component does not exhibit SRP in the area considered as the boundaries, wherein the foil can be original or have a pattern different from SRP. In some embodiments, the boundaries extend over each edge of the metal foil, and in some embodiments where the foil is a long piece with a length more than 10 times longer than the width, the boundaries span less than 1%, less than 2%, less than 5%, or less than 10% of the total width of the metal foil. In some embodiments, one or more non-patterned strips are present near or at the center along the long axis of the component, which are designed for practical and industrial purposes, such as cutting the component into narrower strips. In such embodiments, the majority of the component contains SRP, and the narrow strips of the original foil separate the wide strips of SRP.

[0124] According to an embodiment of the present invention, the seamless repeating pattern is defined or constructed by mathematical methods. In some embodiments, the SRP is generated by machine learning.

[0125] roll:

[0126] The metal component provided herein is very thin, has a high surface area to volume ratio, and is highly flexible, meaning that it can be easily bent, folded, and formed without breaking, and can withstand a variety of stresses and forces. Therefore, due to these characteristics and the requirements of the manufacturing and utilization industries, one of the best formats for handling the metal component provided herein is in the form of a roll.

[0127] The long-travel roll of the member provided herein can be described as a cylindrical product, which is composed of a thin metal member wound around an axle. The roll has a fixed width usually and can have a length of tens of meters, hundreds of meters, or even several kilometers. The roll can be packaged with protective materials to avoid any damage during transportation and storage.

[0128] The metal components provided herein can be wound onto a core tube or hollow cylinder, the inner and outer diameters of which can be selected to suit the manufacturing and use settings.

[0129] Foil reinforcement:

[0130] The reinforced metal foils (members) provided herein can be viewed as metal foils that have been reinforced by corrugation to uniformly increase surface area; this form of foil reinforcement is referred to herein as "corrugation reinforcement" and the property affected is referred to as "functional porosity", as that term is defined below.

[0131] In some embodiments, the metal component is corrugated, folded, protruding, bent, twisted, undulating, or a combination thereof (corrugation enhancement), in other words, the metal component exhibits corrugation enhancement.

[0132] In embodiments where the foil exhibits more than one type of enhancement simultaneously, each type of enhancement needs to be substantially uniform over the entire area of ​​the foil. In some embodiments, the uniformity of each type of enhancement is required to correspond to the size of its structural elements, such as the standard deviation of the structural elements in size and shape estimated by the similarity between primitives (tile similarity).

[0133] The term "size" as used herein refers to the characteristic dimension of an object or structural element. When referring to the size of multiple objects, it refers to the average value obtained by measuring the size of a representative set of objects. The size of a circular object can refer to the diameter of the object. In the case where the object is non-circular, the size of the non-circular object can refer to the diameter of the corresponding circular object, wherein the corresponding circular object exhibits or has a set of specific derivable or measurable features, which are substantially the same as the features of the non-circular object. Alternatively or jointly, the size of a non-circular object can refer to the average value of various orthogonal dimensions of the object. Therefore, for example, the size of an elliptical object can refer to the average value of the major axis and minor axis of the object. When referring to a group of objects having a specific size, it is envisioned that the object can have a size distribution around the specific size. Therefore, when used in this article, the size of a group of objects can refer to the typical size of the size distribution, such as the average size, median size or peak size.

[0134] Functional Porosity:

[0135] In the context of the present invention, a reinforced metal foil is referred to as having a non-zero functional porosity. The phrase "functional porosity" as used refers to a structural property of an object that defines and quantifies the available volume within a minimum bounding box (MBB) of said object. A minimum bounding box is the smallest bounding cuboid of an object, as this geometric concept is known in the art. In the context of a foil defined as being unlimited in width and length, the concept of MBB refers to an arbitrarily selected portion, section or fragment of said foil, or to a thickness dimension, such as Figure 4 as shown in .

[0136] The usable volume is considered to be all the volume within the MBB that is not occupied by the material of the object. For corrugated foils, the functional porosity (P f ) is calculated as defined in Equation 1:

[0137] P f =(T b –T l ) / T b Eq.1.

[0138] Where T l is the thickness or local thickness of the original (smooth) foil, T b is the thickness of the corrugated member or the MBB thickness.

[0139] For a more general example, such as converting a web into a corrugated member according to an embodiment of the present invention, the functional porosity (P or P) of the member f ) is the volume fraction of the MBB not occupied by the building material, as defined in Equation 2:

[0140] P f =1–V m / V b Eq.2

[0141] Where V m is the volume occupied by the building block material, V b is the volume of the MBB including the building block material and voids. Functional porosity can also be expressed as a percentage of thickness or volume. The volume of a building block provided herein can be determined by dividing its mass by its density (m / cm 3 ). Here, the density of the foil material is given in units of mass per unit volume. Therefore, by recording the density of the component material, measuring the mass of the component, and determining the volume of the MBB, the functional porosity of the component can be calculated. For example, a foil that is wrinkled to exhibit peaks and valleys has a higher functional porosity than a flat / smooth foil made of the same material. In other words, a wrinkled foil will have a higher functional porosity than a flat / smooth foil because a completely flat foil occupying 100% of the MBB would have a functional porosity of zero.

[0142] Corrugation enhances the functional porosity of the metal component. Functional porosity as used herein relates to corrugated components (i.e., corrugated by ridges, ridges / recesses, ridges / creases, valleys / ridges). For example, to calculate the functional porosity of a flat and uncorrugated foil or flat mesh, it should be considered that the thickness of the foil is much smaller than its width or length, however, the holes in the mesh "expose" the inner wall, allowing access to a larger surface area of ​​the foil, and in terms of volume, the mesh releases space that would otherwise be occupied by metal. Therefore, the functional porosity of a mesh with a finite thickness is higher than that of the original (non-perforated) foil. It is obvious that the density, shape and size of the pores (pore geometry) affect the functional porosity of the mesh, and the thicker the foil, the more profound the effect of the pore geometry on the functional porosity.

[0143] Figure 2 A simplified illustration of the concepts of local thickness, bounding box thickness and functional porosity is shown, where a straight horizontal thick black band (top) represents a longitudinal cross-section of a pristine foil with a given local thickness (shown on the right side of the cross-section), and shows the minimum bounding box (dashed rectangle) of the web (left), the MBB of a foil with wrinkled reinforcement (right), and the MBB and its thickness associated with a web with wrinkled reinforcement (bottom).

[0144] As can be seen in Figure 2As can be seen in the figure, each reinforcement increases the free volume within the MBB, where the perforations in the mesh increase the surface area within the MBB and the wrinkling reinforcement also increases the volume of the MBB; as can be further seen, when the mesh is used as the basis of a component, the wrinkling reinforcement of the mesh increases the functional porosity to a maximum value.

[0145] In some embodiments, the constructs provided herein are characterized by a functional porosity of at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 100%, 105%, 110%, 115%, 120%, 125%, 130%, 135%, 140%, 145%, 150%, 155%, 160%, 165%, 170%, 175%, 180%, 185%, 190%, 195%, or at least 200% and more. In some embodiments, the functional porosity of the component is in the range of 5-100%, or 10-100%, or 50-150%, or 50-200%, or 100-150%, or 100-200%.

[0146] Wrinkle Enhancement:

[0147] Corrugated metal foils are used in a variety of applications, including packaging materials, structural materials, and electrical and thermal insulation. Corrugation in thin metal foils refers to the process of creating ridges or grooves in the foil in order to increase its surface adhesion and surface area, strength and stiffness. This is usually achieved by subjecting the foil to high pressure, which causes it to deform and take on a wavy or bumpy structure. The resulting corrugated foil is stronger, more resistant to bending and deformation, and has a larger surface area than a flat foil of the same initial thickness.

[0148] In some embodiments, including any of the above embodiments, the original foil or metal mesh presents a non-planar patterned metal member (a non-smooth embossed structure protruding from the general plane of the foil), that is, the foil or mesh is corrugated, folded, protruding, bent, twisted, undulating, or a combination thereof, collectively referred to herein as a non-planar patterned foil or corrugated foil. The term "non-planar" as used herein refers to a substrate that is not flat, not smooth, not planar, does not lie or can be confined in a single plane, has a three-dimensional quality, or has an angle less than 180° or greater than 180° on its surface.

[0149] The term "corrugation" as used herein refers to a plurality of convex and concave embossed structural elements that impart a patterned structure, a regular surface roughness, and / or a regular surface waviness. The term "corrugation" as used herein combines and encompasses protrusions and depressions, "dual-face convex embossing" and / or "dual-face concave embossing," and refers to structural elements that produce protrusions and depressions within the same design on a material. In some embodiments, the size, shape, spacing, and relative orientation of the corrugated structural elements are regular. According to an embodiment of the present invention, corrugation is defined as a plurality of non-perforated structural elements arranged in a seamless repeating pattern (SRP), wherein the term "non-perforated" refers to a discernible structural feature on the surface of the foil that is not a hole and does not disrupt the surface to allow a substance to pass through.

[0150] Metal foils reinforced by corrugation following a seamless repeating pattern are also referred to herein as SRP corrugated members.

[0151] Unlike through-holes, non-perforated structural elements, such as creases, can span any length relative to the dimensions of the component, i.e., a crease can extend from one side to the other while forming part of a SRP parallel to the crease. Furthermore, unlike through-holes, non-perforated structural elements can disturb the surface on one side thereof and can be either protruding (e.g., a peak) or concave (e.g., a valley), depending on the definition of the "top side" and "bottom side" of the component. Thus, non-perforated structural elements can be divided into a set of individual elements, which can form a single localized protrusion, and a set of extended elements, which can form a ridge spanning the foil, terminating at the edge of the foil.

[0152] Non-limiting examples of non-perforated structural elements include protrusions, ridges, creases, depressions, peaks, protrusions, ridges and valleys. The shape of a non-perforated individual structural element can be defined by the "footprint" of the element on the surface of the foil, such as how it looks from above. The shape of a non-perforated extended structural element can be defined by a cross section of the foil perpendicular to the overall direction of the element. For example, a simple circular protrusion / depression is an example of an individual non-perforated structural element with a circular (circle) shape, and the shape of the undulating parallel ridges / valleys is a sine (sine wave).

[0153] Figure 3 Nine non-limiting examples of seamless repeating patterns provided by corrugation enhancements according to some embodiments of the present invention are shown.

[0154] Figure 4 Schematic diagrams of exemplary components showing rounded concave and convex SRP provided by corrugation reinforcement using separate non-perforated structural elements are shown, along with the local thickness and bounding box thickness of the exemplary components according to some embodiments of the present invention.

[0155] The height of a corrugated structural element refers to the vertical distance from the bottom side to the top side of the member, in other words, the thickness of the MBB. For example, a valley is a depression in the surface, and a peak is the midpoint of two adjacent valleys that extend above a portion of the surface. The peak-to-valley vertical distance, or peak-to-valley distance, is the distance between the top of a peak and the bottom of an adjacent valley, and is also the thickness of the MBB.

[0156] The horizontal distance between non-perforated structural elements ("horizontal spacing") is essentially the distance between the centers of two adjacent structural elements (see Figure 3 ). In some embodiments, in the wrinkling enhancement, the horizontal distance between the centers of two adjacent individual or extended non-perforated structural elements is in the range of 1-1000 μm, or about 10-100 μm, or 20-100 μm, 30-100 μm, 40-100 μm, 50-100 μm, 60-100 μm, 70-100 μm, 80-100 μm, or about 90-100 μm. In some embodiments, the horizontal distance between the centers of two non-perforated structural elements is less than about 1,000 μm, less than about 750 μm, less than about 500 μm, less than about 250 μm, less than about 100 μm, less than 90 μm, less than 80 μm, less than 70 μm, less than 60 μm, less than 50 μm, less than 40 μm, less than 30 μm, less than 20 μm, less than 15 μm, less than 10 μm, less than 9 μm, less than 8 μm, less than 7 μm, less than 6 μm, less than 5 μm, or less than 4 μm. In some embodiments, the horizontal distance between the centers of two non-perforated structural elements is at least about 10 μm, 50 μm, 100 μm, 150 μm, 200 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm, 800 μm, 900 μm, or at least about 1,000 μm.

[0157] It is to be noted here that in some corrugation methods where a thin foil is pressed against a flat or circular corrugated template (or vice versa) in order to imprint the SRP of the template onto the foil, the thickness of the foil may vary depending on the type of corrugation employed. In some embodiments, corrugation is achieved by mechanically expanding the mesh. For example, if the mesh is characterized by a functional porosity of 55% (45% of the volume is occupied by metal), has a thickness of 20 μm, and the mesh is treated to present a corrugated structural element, during which the mesh is stretched to a local thickness of 100 μm (5 times stretching), this will reduce the metal portion in the component by 5 times, from 45% to 9%. This also increases the functional porosity from 55% to 91%. In some embodiments, the stretching is achieved using an embossing technique. In certain instances, the stretched component is long and is rolled up for use in a factory assembly line.

[0158] The above can be described numerically as follows:

[0159] P (0) is the functional porosity of the original foil or mesh;

[0160] P (1) is the functional porosity after wrinkling (stretching);

[0161] M (0) is the fraction of metal in the original foil or mesh;

[0162] M (1) is the fraction of metal in the corrugated metal component;

[0163] T (0) is the local thickness of the original foil or web; and

[0164] T (1) is the local thickness after wrinkling (stretching),

[0165] Therefore, M (0) =1-P (0) .

[0166] Since no material is added or removed during the corrugation process:

[0167] M (1) =M (0) ·(T (0) / T (1) ),and

[0168] P (1) =1-M (1) .

[0169] Therefore, from 50% of P (0) Start and stretch 4 times to get P (1) =1-M (1) =1-50% / 4=87.5%. (0) =80% to get P (1) =95%.

[0170] In some embodiments, stretching (local thinning) occurs primarily where the angles of the structural elements are sharpest or where the flatness changes dramatically. This thinning or stretching of the foil may result in tears in the foil, which may be intentional, thereby forming through holes; tears in the foil are otherwise to be avoided. Therefore, the size of the corrugated structural elements also depends on the thickness of the foil.

[0171] In some embodiments, the ratio of the thickness of the MBB to the local thickness (thickness of the original foil) is at least 1.1:1, at least 1.2:1, at least 1.3:1, at least 1.4:1, at least 1.5:1, at least 1.6:1, at least 1.7:1, at least 1.8:1, at least 1.9:1, at least 2:1, at least 2.2:1, at least 2.3:1, at least 2.4:1, at least 2.5:1, at least 2.6:1, at least 2.7:1, at least 2.8:1, at least 2.9:1, or at least 3: 1. In some embodiments, the ratio of the thickness of the MBB to the local thickness is in the range of 1.1:1-2:1, or 1.1:1-3:1, or 1.1:1-4:1, or 1.1:1-5:1. In some embodiments, the MBB thickness is 5-10 times greater than the local thickness. The ratio of the MBB thickness to the local thickness is also an indicator of the functional porosity on the non-perforated member with corrugated reinforced SRP, ie, a ratio of 1.1:1 corresponds to a functional porosity of 10% and a ratio of 3:1 corresponds to a functional porosity of 200%.

[0172] In some embodiments, the thickness of the MBB of the component with corrugation reinforcement is in the range of 6 μm to 5,000 μm. In some embodiments, the thickness or vertical distance of the MBB of the component with corrugation reinforcement is less than about 1,000 μm, less than about 750 μm, less than about 500 μm, less than about 250 μm, less than about 100 μm, less than 90 μm, less than 80 μm, less than 70 μm, less than 60 μm, less than 50 μm, less than 40 μm, less than 30 μm, less than 20 μm, less than 15 μm, less than 10 μm, less than 9 μm, less than 8 μm, less than 7 μm, less than 6 μm, less than 5 μm or less than 4 μm. In some embodiments, the MBB thickness of the component with corrugation reinforcement is at least about 5μm, 10μm, 20μm, 30μm, 40μm, 50μm, 60μm, 70μm, 80μm, 90μm, about 100μm, 150μm, 200μm, 300μm, 400μm, 500μm, 600μm, 700μm, 800μm, 900μm, 1,000μm, 1,200μm, 1,400μm, or at least about 1,500μm (about 1.5mm).

[0173] In some embodiments, the size of an individual non-perforated structural element (diameter, footprint, or widest horizontal span at the bottom of the structural element) is in the range of 10 μm to 5,000 μm. In some embodiments, the size of an individual non-perforated structural element is in the range of about 10-500 μm, or about 10-400 μm, about 10-300 μm, about 10-200 μm, or about 10-100 μm. In some embodiments, the size of individual non-perforated structural elements is less than about 500 μm, less than about 400 μm, less than 350 μm, less than 300 μm, less than 250 μm, less than 200 μm, less than 150 μm, less than 100 μm, less than 90 μm, less than 90 μm, less than 80 μm, less than 70 μm, less than 60 μm, less than 50 μm, less than 40 μm, less than 30 μm, less than 20 μm, less than 15 μm, less than 10 μm, less than 9 μm, less than 8 μm, less than 7 μm, less than 6 μm, less than 5 μm or less than 4 μm.

[0174] In some embodiments, the corrugated SRP comprises extended structural elements, such as folds or undulations extending perpendicular to the longitudinal axis of the member, which is one long, continuous sheet. In some embodiments, the extended structural elements cross the longitudinal axis diagonally.

[0175] In some embodiments, the corrugated SRP comprises individual structural elements, such as protrusions (convex) and depressions (concave), protrusions on one side of the member (protrusions only) or protrusions on both sides of the member (protrusions and depressions). In some embodiments, the individual structural elements are arranged in a straight line. In some embodiments, the individual structural elements are aligned in an inclined line, which is inclined relative to the longitudinal axis of the member or one of its sides. In some embodiments, as described above and Figure 3 As illustrated in FIG, the individual structural elements are arranged in tiles / primitives.

[0176] The post-production uniformity of the wrinkled enhanced SRP can be determined by any experimental statistical method using optical scanning and identification of wrinkled samples. In some embodiments, the standard deviation of the wrinkled element overlap is less than 15%, less than 10%, or less than 5%.

[0177] Continuous manufacturing process:

[0178] The method of making the components provided herein facilitates the production of a continuous SRP on or in a continuous metal foil (also referred to herein as a metal substrate) and includes a continuous additive manufacturing method, a continuous subtractive manufacturing method, a bonding method, and in some embodiments, also includes a continuous post-manufacturing reinforcement step. The present invention provides a technique for cheaply and quickly producing reinforced long foils with high and uniform porosity, which involves enhancing the functional porosity of thin foils so that these reinforced foils provide the benefits of 3D structures (e.g., metal foams) while maintaining the benefits of uniformity (non-random SRP), production speed, production cost, and roll readiness obtained from thin foil production methods.

[0179] In some embodiments, including any of the embodiments above, reinforcing the metal foil, substrate, or surface includes increasing the usable volume relative to the total volume of the bounding box, or in other words, increasing its functional porosity.

[0180] In some embodiments, including any of the above embodiments, the method includes providing a metal foil having a patterned surface, wherein the metal is initially a planar surface, but is transformed into a non-planar metal by corrugation enhancement. The transformation can be achieved using electrical, mechanical, magnetic or other forces or combinations thereof.

[0181] In some embodiments, described herein is a method of making a component provided herein, wherein the method includes providing a metal foil and reinforcing the metal foil such that the metal is non-planar and has a functional porosity of 10-200% (corrugation reinforcement).

[0182] In some embodiments, including any of the above embodiments, the method includes providing a substrate in the form of a raw metal foil or mesh, including applying a localized mechanical force to the substrate. In other embodiments, the wrinkling enhancement includes pressing on the metal foil with a metal tool (plane or cylinder), thereby forming a non-perforated structural element in the metal foil. In certain other embodiments, the method includes pressing on the metal foil with a metal structure (e.g., a template or substrate), thereby producing a non-planar non-perforated structural element in the metal foil.

[0183] In certain other embodiments, the metal foil is modified using a stretching process. In certain other embodiments, the metal foil is modified using a stamping process. In certain other embodiments, the metal foil is modified using a twisting process. In certain other embodiments, the metal foil is modified using a convex / concave embossing process. In certain other embodiments, the metal foil is modified using a bending process. In certain other embodiments, the metal foil is modified at room temperature. In certain other embodiments, the metal foil is modified at an elevated temperature.

[0184] In some embodiments, including any of the above embodiments, the method includes providing a component provided herein by deforming a metal substrate. In some embodiments, including any of the above embodiments, the method includes strengthening the metal foil, including applying a mechanical force to a metal substrate (e.g., an original thin metal foil or mesh). In certain embodiments, the method includes strengthening the metal by stretching the metal substrate. Here, deformation includes changing the shape of the metal substrate, changing the functional porosity of the metal substrate, or a combination of two or more of the above. Here, strengthening the substrate includes increasing some external dimensions of the metal surface, such as its MBB thickness and / or functional porosity. For example, strengthening the substrate may include increasing the surface area of ​​the metal surface. Strengthening may include increasing the length or width of the metal surface. In other embodiments, strengthening the substrate includes stretching the metal to make it longer or wider, but also thinner.

[0185] In some embodiments, including any of the above embodiments, the method further comprises stretching the solid foil or mesh; wherein the stretching also increases the pore size of the mesh. In other examples, this type of reinforcement increases the length or width of the foil or mesh. In other examples, this type of reinforcement increases the length or width of the foil or mesh and also reduces the thickness of the foil or mesh. In some embodiments, a combination of the above types of reinforcement steps are implemented.

[0186] In some embodiments, the methods herein include the step of increasing the functional porosity of the metal foil or mesh or the member by corrugation reinforcement. In some embodiments, the metal foil or mesh formed by continuous electroforming or other methods is subjected to mechanical forces, which introduce non-perforated (corrugated) structural elements into the foil or mesh in a continuous manner.

[0187] Current collector:

[0188] The current collector (CC) has the following general roles in a battery system: (i) since typical electrodes are made by casting a slurry (a mixture of active materials, polymer binder, and carbon additives) on the CC, the CC supports the electrode layers, and (ii) the CC provides an electrical path to transfer electrons between the electrode material and the external circuit. By controlling the properties of the CC, the following effects can be obtained: (i) the lower the thickness and the higher the strength, the more active materials can be stacked in a limited space, resulting in a high volumetric energy density; (ii) by strengthening the connection between the active material and the CC with a wide contact area, additional electron paths can be achieved, thereby reducing the internal resistance of the battery. Typically, Cu and Al are used as CCs for the anode (0-1.5 V relative to Li / Li+) and the cathode (3-4.7 V relative to Li / Li+), respectively, due to their electrochemical stability and active material compatibility in each reaction potential range.

[0189] The present invention provides a reinforced metal foil that exhibits high functional porosity and uniformity, thereby allowing a larger amount of active material slurry to be loaded thereon, increasing the contact surface area between the active material and the CC, and exhibiting uniformity over the entire area of ​​the CC, thereby reducing delamination of the active material, cracking, swelling, unfavorable formation of "hot spots", and other mechanical failures that lead to battery failure.

[0190] Compared to solid flat and smooth foil current collectors, current collectors with large surface area and low density (low weight) can have several advantages in electrodes of lithium-ion batteries. Improved active material utilization: Larger surface area allows more active materials such as lithium ions to be deposited on the current collector, thereby increasing the overall energy density of the electrode. Improved conductivity: High surface area current collectors can have greater conductivity, which can improve the overall performance of the battery. Reduced weight: Low weight current collectors can reduce the overall weight of the battery, making it more portable and convenient for use in applications such as electric vehicles and portable electronic devices. Better mechanical stability: High surface area current collectors can have greater mechanical stability, which can improve the overall durability and life of the battery. Better rate performance: High surface area current collectors can have greater rate performance, which means that the battery can be charged and discharged faster without reducing its performance. Overall, current collectors with large surface area and low density can improve the overall performance and efficiency of lithium-ion batteries.

[0191] In some embodiments of the present invention, the reinforced metal foil acting as a current collector with large surface area and low density (high functional porosity) provides the following advantages:

[0192] (i) The lower the thickness and the higher the strength, the more active materials can be packed in a limited space, resulting in high volumetric energy density;

[0193] (ii) by strengthening the connection between the active material and CC with a wide contact area, additional and shorter electron pathways can be achieved, thereby reducing the internal resistance of the battery; and

[0194] (iii) Low-cost, rapid and continuous manufacturing and provision of industrial-sized coils facilitates machinery and processes used in contemporary and advanced electrode and battery industries.

[0195] Thus, according to one aspect of some embodiments of the present invention, there is provided a current collector, in the sense of being a part of an electrode, which collects electrons from an electrode material and transfers them to an external circuit, wherein the CC consists of or comprises the reinforced metal foil (member) provided herein.

[0196] As used herein, the term "current collector" refers to a substrate that conducts electrons in a manner sufficient for use in a battery or electrochemical cell to complete an electrical circuit at the cathode and anode. The CC is typically made of a metal such as copper, aluminum, or nickel. Other metals such as magnesium, tungsten, cobalt, iron, titanium, platinum, tungsten, and gold, and any alloys thereof, as well as alloys or combinations of metals such as steel, may also be used. In the context of a secondary battery, the CC in the cathode conducts electrons into the cathode during discharge and conducts electrons out of the cathode during charge, while in the anode, the CC conducts electrons into the anode during charge and conducts electrons out of the anode during discharge.

[0197] The current collector may also include contacts and contact leads, terminals, and other features that are common and / or required as part of a current collector, or other features required for its assembly and implementation in an electrical device, and these additional features (all or any selection thereof) are encompassed in the definition of current collector used herein.

[0198] In some embodiments, the current collector comprises or consists of a member that undergoes corrugation reinforcement as defined and exemplified herein.

[0199] In some embodiments, the current collector comprises or consists of a web that undergoes corrugation reinforcement as defined herein.

[0200] In some embodiments, including any of the above embodiments, the current collector is provided in the form of a roll, as that term is defined above.

[0201] In some embodiments, the current collector provided herein comprises a significantly different metal layer (layer). Here, significantly different layers are defined as multiple metal layers that can be distinguished from each other under microscope imaging conditions. If the layers are melted, bonded, welded, brazed or diffused together or to each other so that the boundaries between them cannot be observed under microscope imaging, then the layers are not significantly different. However, if the layers are bonded together in a manner that the boundaries between them can be distinguished under microscope imaging, then the layers are referred to as being significantly different.

[0202] In the context of the present invention, particularly in the context of multilayer current collectors, a layer comprises or consists of a reinforced metal foil as provided herein. For example, the CC may have a total thickness of 100 μm and include five discernible layers, each 20 μm thick, and when stacked on top of each layer, the five layers add up to a total thickness of 100 μm. In some embodiments, the metal layers may be independently corrugated or pristine.

[0203] In some embodiments, including any of the above, the CC comprises distinct layers, each layer independently characterized by a total thickness (MBB thickness) in the range of about 4-20 μm, or 5-20 μm, or about 10-50 μm.

[0204] In some embodiments of the invention, CCs are made by stacking individual building blocks provided herein into metallic layers and are further characterized by indistinguishable layers (the layers are not distinct from each other).

[0205] According to an aspect of some embodiments of the present invention, there is provided a current collector suitable for an electrode (e.g., a battery), comprising at least one reinforced metal foil as proposed herein, wherein the reinforced metal foil is characterized by at least some of the following features:

[0206] seamless repeating pattern of non-perforated structural elements;

[0207] Local thickness in the range of 4-100 μm; and

[0208] Functional porosity of at least 10%.

[0209] Wrinkled current collector:

[0210] According to an aspect of some embodiments of the present invention, there is provided a current collector suitable for an electrode (e.g. a battery), comprising at least one reinforced metal foil as proposed herein, wherein the reinforced metal foil is produced by a continuous corrugation process such that it can be produced with a width of at least 0.1 m and an unlimited length of at least 0.5 m, and characterized in that:

[0211] seamless repeating pattern of non-perforated structural elements (corrugated SRP);

[0212] Local thickness in the range of 4-100 μm; and

[0213] Functional porosity of at least 10%.

[0214] In some embodiments, the current collector comprises or consists of a reinforced metal foil (member) produced by any continuous manufacturing technique known in the art and including a continuous corrugation process step (which imparts corrugation reinforcement to the member), these terms and characteristics being described above.

[0215] Unless otherwise specified, the member is corrugated but not perforated, i.e., it is not a mesh. In such embodiments, the corrugated SRP may include individual non-perforated structural elements and / or expanded non-perforated structural elements as defined above, such that the functional porosity of the corrugated member exceeds 10% as described herein.

[0216] In some embodiments, the size (diameter, widest span at bottom) of individual non-perforated structural elements in the SRP of the corrugated member is in the range of 10 μm to 5,000 μm or 10-500 μm. In some embodiments, the horizontal distance between non-perforated structural elements in the SRP of the corrugated member is in the range of 100-5000 μm or 100-500 μm.

[0217] In some embodiments, the horizontal distance between two adjacent non-perforated structural elements in the corrugated reinforcement is in the range of 1-2000 μm or about 10-100 μm.

[0218] In such embodiments, the height of the corrugated structural elements characterizing the component can be expressed as a ratio between local thickness and MBB thickness, where the MBB of the non-corrugated foil is equal to the local thickness of its initial thickness before corrugation. In such embodiments, the ratio of the MBB thickness to the local thickness (thickness of the original foil) is at least 1.1:1-2:1. In some embodiments, the ratio of the MBB thickness to the local thickness is at least 3:1, 4:1, 5:1, 10:1 or at least 20:1. For example, an original foil having a local thickness of 10 μm can be enhanced by corrugation to present an MBB thickness of 200 μm.

[0219] In some embodiments, the MBB having corrugated reinforcement has a thickness in the range of 6 μm to 5,000 μm.

[0220] In some embodiments, including any of the above embodiments, the reinforced metal foil produced by the continuous corrugation process is provided in the form of a foil roll, wherein the width of the foil or the width of the roll is at least 0.1m, at least 0.5m, at least 1m, at least 2m, at least 3m, at least 4m, or at least 5m wide and the length is at least 0.5m, 1m, 10m, 100m, 200m, 300m, or 400m long.

[0221] Enhanced current collector:

[0222] In some embodiments, the current collector comprises or consists of a reinforced metal foil characterized by corrugation reinforcement, the foil being produced by a continuous process. In some embodiments, the CC produced by a continuous process comprises or consists of copper. In some embodiments, the reinforced metal foil produced by a continuous process is corrugated to exhibit the SRP of a corrugated structural element as presented herein.

[0223] In some embodiments, the current collector produced by the continuous process comprises or consists of aluminum. In some embodiments, the reinforced metal foil produced by the continuous process is corrugated to exhibit the SRP of the corrugated structural element as proposed herein.

[0224] In some embodiments, including any of the above embodiments, the reinforced metal foil produced by a continuous process as described above and exhibiting corrugation reinforcement is provided in the form of a roll of a metal member, wherein the width of the member or the width of the roll is at least 0.1 m, at least 0.5 m, at least 1 m, at least 2 m, at least 3 m, at least 4 m, or at least 5 m wide and the length is at least 0.5 m, at least 1 m, at least 10 m, at least 100 m, at least 1000 m, or at least 10,000 m long.

[0225] electrode:

[0226] As discussed above, the advantages obtained by the enhanced metal foil provided herein include reducing the mass of the electrode, increasing the amount of active material that can be loaded per unit area, increasing the contact surface area with the active material, improving the electrical pathway within the active material, and all of this while maintaining low production costs and compatibility with large-scale production machinery and processes, compared to the original solid (non-porous) and flat (planar, smooth) metal foils currently used.

[0227] The components and CCs provided herein help to significantly reduce the local current density by expanding the surface area of ​​the CC. Since reducing the current density at the electrode can delay the onset of dendritic growth and slow down the growth rate, the CCs provided herein effectively mitigate dendritic growth. In addition, since the CC acts as a matrix for the Li metal, the CCs provided herein block the randomly generated Li metal-electrolyte interface and the internal pressure changes caused by the volume change of the Li metal during the cycle.

[0228] Compared to other 3D porous metal sheets that have been proposed and demonstrated in the art, the present invention provides a solution to the extremely high costs, long manufacturing times and, most importantly, the very limited production capacity of all other 3D porous structures, which cannot be mass-produced into rolls of tens and hundreds of meters in length, which are required for contemporary electrode coating production in large-scale production plant facilities. The components provided herein and the current collectors comprising or consisting of the same can be implemented in electrode production in the form of a continuous roll of feed foil that is fed into an active material coating device and cut into individual electrodes at a later time.

[0229] Thus, according to some embodiments of the present invention, there is provided an electrode, for example in the context of a battery or capacitor, comprising at least one current collector and an active electrode material (also referred to as a coating material) constructed on the CC, wherein the current collector comprises or consists of at least one reinforced metal foil (member) provided herein. Unless otherwise expressly stated, throughout the present invention, the term "electrode" refers to both anodes and cathodes.

[0230] Electrode coating is an important part of the battery manufacturing process, contributing greatly to the final microstructure and therefore related to the functionality of the resulting electrode. According to embodiments of the present invention, the coating of the reinforced metal foil provided herein can be carried out by various routes, and the coater device can be a pull-down coater commonly used in research laboratories to produce small coatings, or for larger industrial applications, a roll-to-roll (i.e., R2R or reel-to-reel) coater, and the components disclosed herein are most suitable for such coaters. In a roll-to-roll setting, the geometry of the coater used to coat the components according to some embodiments of the present invention can be a doctor blade (a fine blade set at a fixed gap from the CC), a comma rod (a comma-shaped geometry with a curved leading edge), a slot die (the coating material is extruded from the slot onto the CC), a "knife-to-roll" (the coating material is distributed onto the CC and then passed through a knife and a roller), a "reverse roller", a "Meyer rod" (where the roller applies the coating material to the CC, and then the Meyer rod meters the correct amount), and these methods and devices are known in the art. The coater can be carried out while the CC is supported by a roller. Alternatively it can also be applied to an unsupported CC under tension, which is known as tension web coating.Other electrode coating methods known in the art can be used to coat the current collectors described herein.

[0231] The coating material is introduced directly onto the CC without causing additional morphological deformation of the CC, and can be introduced onto one or both sides of the member according to the design requirements of the battery. For example, the wrinkled member provided herein has been used in an industrial electrode coater to successfully produce electrodes for LiBs, demonstrating the feasibility of large-scale production and applicability to practical industry. This simple manufacturing process can also be associated with its cost-effective characteristics.

[0232] Thus, according to some embodiments of the present invention, the electrode is produced by any known R2R process using a roll of the reinforced metal foil provided herein.

[0233] In some embodiments, the thickness of the electrode including the coating material is greater than the total thickness of the current collector (MBB thickness) due to the added layer of coating material constructed on the current collector. In some embodiments, the thickness of the electrode including the coating material is similar to the total thickness of the current collector including the added layer of coating material constructed on the current collector (MBB thickness).

[0234] Figure 5A -C shows a schematic diagram of a coating scheme for a reinforced metal foil according to some embodiments of the present invention, wherein the top cross-sectional view ( Figure 5A ) shows an electrode exhibiting the same thickness as the total thickness of the corrugated foil member (MBB thickness), similar to the middle figure showing the corrugated mesh as the metal member ( Figure 5B ), and the bottom graph ( Figure 5C) shows an electrode that exhibits a greater thickness compared to the total thickness of the corrugated member (MBB thickness).

[0235] In some non-limiting embodiments where the thickness of the entire electrode is similar to that of the current collector, the CC has a thickness of 9-12 μm or up to 100 μm. In some non-limiting embodiments where the thickness of the entire electrode is thicker than that of the current collector, the current collector has 50 μm protrusions on its surface and a porosity greater than 90%, provided by the corrugation.

[0236] As discussed herein, a current collector can include more than one metal layer, wherein at least one or all of the layers are a reinforced metal foil as provided herein.

[0237] Coating Material:

[0238] Since the reinforced metal foils provided herein are designed to be suitable for contemporary industrial electrode production, all known and commonly used processes, methods and techniques for producing active coating materials and applying them to current collectors are applicable hereto.

[0239] In some embodiments, the process includes coating a current collector with a wet or fluid active material composition in the form of a slurry, paste, liquid, etc. In some embodiments, the coating is provided by a dry (solvent-free) coating, wherein the active material is deposited on the current collector, using little or no solvent to carry the active material.

[0240] Electrode comprising a wrinkled current collector:

[0241] According to some embodiments of the present invention, there is provided an electrode comprising at least one current collector and an active electrode material constructed on the CC, wherein the current collector comprises or consists of at least one reinforcing metal foil (member) in the form of a corrugated metal foil as proposed above. In some embodiments, the member has no perforations.

[0242] Batteries and Power Equipment:

[0243] In view of the above, a battery or battery pack is provided, which comprises at least one electrode, wherein the electrode comprises at least one reinforced metal foil provided herein, or wherein the electrode comprises a current collector, and the current collector comprises at least one reinforced metal foil provided herein (member; object), or consists of it. It should be noted here that although a battery is a single unit of a device that converts chemical energy into electrical energy, and a battery pack is a collection of batteries that convert chemical energy into electrical energy, the terms "battery" and "battery pack" are used interchangeably herein.

[0244] Accordingly, an electric power device is provided, which includes the battery, battery array, battery pack or battery pack array provided herein.

[0245] In some embodiments, the cell or battery comprises at least one electrode comprising at least one current collector, wherein the CC is a corrugated metal member or a corrugated reinforced metal foil as described herein.

[0246] In some embodiments, the cell or battery comprises at least one electrode comprising at least one current collector, wherein the CC is a corrugated metal mesh as described herein.

[0247] The power devices contemplated within the scope of the present invention include any power device that can use a battery or battery pack as a primary, auxiliary or secondary energy source. Alternatively, the power device is a power device that includes at least one battery pack, wherein the device uses the power stored in the battery pack as its power source.

[0248] Examples of electric devices include, but are not limited to, electric vehicles for transportation in air, land, water, and / or space, smart phones, laptop computers, portable media players, power tools, toys, heating devices, cooling devices, lighting products (e.g., flashlights), etc.

[0249] In some embodiments, the power device is a device that requires a high power density battery pack, such as a vehicle (e.g., an electric car). In terms of a battery pack, power density refers to the amount of electricity that can be stored or delivered by a battery pack per unit volume or unit mass. High power density means that a battery pack can store or deliver a relatively large amount of electricity in a relatively small space or weight. This is one of the features of a battery pack using an enhanced metal foil provided herein, which is designed for portable electronic devices and electric vehicles, where size and weight are key factors. High power density batteries can also have a higher energy density, which means that they can store more energy per unit weight or volume.

[0250] It is anticipated that many related enhanced metal foils will be developed during the life of the patent expiring on this application, and the scope of the phrase "enhanced metal foil" is intended a priori to include all such new technologies.

[0251] It should be understood that certain features of the invention described in the context of separate embodiments for the sake of clarity may also be provided in combination in a single embodiment. Conversely, various features of the invention described in the context of a single embodiment for the sake of brevity may also be provided separately or in any suitable sub-combination, or in any other described embodiment of the invention where appropriate. Certain features described in the context of various embodiments should not be considered essential features of those embodiments unless the embodiments do not work without those elements.

[0252] Various embodiments and aspects of the present invention as delineated hereinabove and as claimed in the claims section below find experimental support in the following examples.

[0253] Example

[0254] Reference is now made to the following examples, which together with the above descriptions illustrate some embodiments of the invention in a non-limiting fashion.

[0255] Example 1

[0256] Wrinkle Enhancement

[0257] Copper and aluminum foils with local thicknesses of 12 μm and 60 μm, respectively, and at least 125 m in length were subjected to a roll-to-roll corrugation enhancement process as described herein. The SRP of the non-perforated structural elements consisted of circular depressions spaced about 500 μm apart horizontally and arranged in a hexagonal array, resulting in a total corrugated thickness (MBB thickness) of 60 μm in copper and 190 μm in aluminum.

[0258] Fig. 6A -B shows a micrograph taken using a Nikon eclipse LV100ND optical microscope, capturing a 12 μm thick copper foil ( Fig. 6A ) and 60 μm thick aluminum foil ( Figure 6B ), each foil having undergone corrugation reinforcement in the form of hexagonally arranged circular depressions spaced approximately 500 μm apart horizontally from each other.

[0259] Example 2

[0260] Active material coating

[0261] To demonstrate the ability of the enhanced metal foil provided herein to load electrode active materials, the corrugated aluminum foil presented in Example 1 above was used as a current collector and coated with a cathode active material slurry comprising 95 wt.% NMC811 (LiNi 2O3) suspended in NMP (N-methyl-2-pyrrolidone slurry carrier). 0.8 Mn 0.1 Co 0.1O2), 3wt.% polyvinylidene fluoride (PVDF), C65 (nano carbon black conductive additive; 2wt.%).

[0262] According to some embodiments of the present invention, the slurry is applied to an aluminum current collector member using a draw-down coater and dried to form an exemplary cathode. Thereafter, aluminum is chemically etched from the cathode to obtain a Figure 7 The morphology of the dry active material residual layer is shown in FIG.

[0263] Figure 7 A photograph taken using a Leica DVM6 optical microscope is shown of a dried layer of a slurry applied to a corrugated aluminum foil or component after aluminum removal by acid etching according to some embodiments of the present invention, showing five protruding protrusions and four depressions pointing to opposite sides.

[0264] Similar experiments were performed with different slurries containing LiFePO4, where the slurries were coated on similar corrugated aluminum foil and dried.

[0265] Figure 8 A SEM micrograph of a wrinkled copper mesh is shown, showing a top view of a copper current collector coated with active material on one side for demonstration purposes.

[0266] Example 3

[0267] Lithium-ion battery with wrinkled current collector

[0268] According to some embodiments of the present invention, multilayer lithium ion pouch cells with a capacity ranging from 1-1.5 Ah are prepared using corrugated copper foil and aluminum foil as current collectors, wherein according to some embodiments of the present invention, the anode is prepared using corrugated copper foil and the cathode is prepared using corrugated aluminum foil.

[0269] The battery includes a graphite anode and a nickel manganese cobalt (NMC622) cathode known in the art, the cathode active material composition is 94wt.% NMC622, 2wt.% PVDF, 2wt.% C65 (carbon black conductive additive), the slurry carrier is N-methylpyrrolidone (NMP), and a standard electrolyte of 1M LiPF6, EC / DEC 1: 1 is used. The active material is coated on the current collector using a standard roll-to-roll machine, and the battery is assembled using standard battery assembly practices.

[0270] The copper current collector for the anode has a local thickness of 12 μm, an MBB thickness of 43.5 μm, and a hexagonal array of circular depressions separated by a horizontal distance of 500 μm. The aluminum current collector for the cathode has a local thickness of 20 μm, an MBB thickness of 63.2 μm, and a hexagonal array of circular depressions separated by a horizontal distance of 500 μm.

[0271] Cathode active area 6 x 10 cm 2 Prior to the cycle test, the pouch cells were first subjected to a forming step at a C rate of C / 20. After forming, the cells were subjected to 1C charge-discharge cycles at room temperature (with regular capacity checks at C / 3).

[0272] The result of the cycle is as follows Fig.9A As shown in , where the capacity retention of the battery is plotted against the number of cycles, with the initial capacity of 1.1 Ah being 100%. The battery can be cycled at a high rate of 1C for more than 450 cycles with 85% of the initial capacity remaining.

[0273] To compare the direct current internal resistance (DCIR) of the pouch cell with wrinkled current collectors relative to the pouch cell with conventional electrodes, as shown in the previous example, the GITT method was used. The internal resistance of the cell was measured at three different SOCs during cell discharge. Fig. 9B A comparison of DCIR as a function of SOC between the two configurations is shown.

[0274] Fig.9A -B shows battery cycling results obtained for a lithium-ion battery comprising a wrinkled current collector according to some embodiments of the present invention, wherein Fig.9A shows the measured values ​​of the retained capacity (capacity scale is a percentage of the initial capacity) of the cells using the corrugated CC configuration provided herein, and Fig. 9B Internal resistance measurements of the cells at various states of charge are shown, with the results compared to those obtained for similar cells containing conventional (flat, non-porous) current collectors.

[0275] Reducing the internal resistance of a battery pack cell has a significant impact on overall battery performance because it allows faster charging and discharging, and charging and discharging with less loss in overall capacity retention. Fig.9A The performance of cells constructed according to some embodiments of the present invention outperforms that of cells using conventional foils for the CC, as seen in Figure 1-B. As can be seen, the cells with the wrinkled CC in the electrode exhibit lower DCIR (more than two times) than the cells with the conventional electrode.

[0276] Example 4

[0277] Exemplary Structural Elements and Corresponding SRPs

[0278] Table 1 shows the combinations of various SRP parameters for wrinkling enhancement.

[0279] Table 1

[0280] Metal Local thickness MBB thickness Horizontal distance copper 8μm 4-30μm 320-1000μm copper 10-12μm 20-60μm 300-200μm copper 20μm 20-120μm 200-100μm copper 50μm 90-120μm 100-50μm aluminum 20μm 30-60μm 320-1000μm aluminum 30μm 30-90μm 320-1000μm aluminum 60μm 90-180μm 500-1000μm aluminum 125μm 130-500μm 500-2000μm

[0281] Example 5

[0282] Reinforced metal foil rolls

[0283] Fig. 10A -B shows a photograph of a reinforced metal foil (metal member) according to some embodiments of the present invention, the foil comprising aluminum and exhibiting corrugation reinforcement, wherein the local thickness is about 20 μm, the vertical distance (height) of the circular protrusions (non-perforated structural elements) (which is also the MBB thickness) is about 72 μm, and the horizontal distance between the structural elements is about 500 μm, wherein Fig. 10A The entire roll and close-up insert of the reinforced metal foil are shown in Fig. 10B is a microscopic image showing a corrugated structural element.

[0284] Fig.11A -C shows a photograph of a reinforced copper foil according to some embodiments of the present invention, which exhibits wrinkling reinforcement, wherein the local thickness is about 12 μm, the MBB thickness is about 100 μm, and the horizontal distance between structural elements is about 500 μm, wherein Fig.11A The entire roll of reinforced metal foil is shown in Fig. 11B A close-up inset is shown in Fig. 11C is a microscopic image showing a corrugated structural element.

[0285] Although the present invention has been described in conjunction with its specific embodiments, it is apparent that many alternatives, modifications and variations will be apparent to those skilled in the art. Therefore, the present invention is intended to cover all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims.

[0286] The applicant's intention is to include all publications, patents and patent applications mentioned in this specification in their entirety into this specification by reference, just as each individual publication, patent or patent application is specifically and individually noted to be included herein by reference when mentioned. In addition, the citation or identification of any reference in this application should not be construed as admitting that the reference can be used as prior art of the present invention. In the case of using section headings, they should not be construed as necessarily restrictive. In addition, any priority document of the application is incorporated herein by reference in its entirety.

Claims

1. An electrode comprising at least one current collector, wherein the current collector comprises at least one metal component, wherein the metal component is characterized in that: seamless repeating pattern of non-perforated structural elements; Local thickness in the range of 3-100 μm; and Functional porosity (Pf) of at least 10%.

2. The electrode according to claim 1, wherein the non-perforated structural element is selected from a single element and an extended element.

3. An electrode according to any one of the preceding claims, wherein the non-perforated structural elements in the seamless repeating pattern have an average size in the range of 10-500 μm.

4. An electrode according to any one of the preceding claims, wherein the horizontal distance between the non-perforated structural elements is less than 1,000 μm.

5. An electrode according to any one of the preceding claims, wherein the seamless repeating pattern is characterised by a uniformity of at least 15%.

6. The electrode of any one of the preceding claims, wherein the metal component comprises a metal selected from the group consisting of aluminum, copper, nickel, gold, cobalt, iron, titanium, steel, stainless steel, and any alloys and combinations thereof.

7. An electrode according to any one of the preceding claims, wherein the local thickness is in the range of 3-20 μm.

8. The electrode according to any one of the preceding claims, wherein the ratio between the thickness of the smallest bounding box of the metal member and the local thickness is in the range of 1.1-5.

9. An electrode according to any one of the preceding claims, wherein the functional porosity is at least 50%.

10. An electrode according to any one of the preceding claims, wherein the metal component is characterized by a tensile strength of at least 20-45 MPa.

11. An electrode according to any one of the preceding claims, wherein: The metal member comprises copper, The seamless repeating pattern of the non-perforated structural elements comprises primitives of circular depressions and / or circular protrusions each having a diameter of less than 500 μm and a horizontal distance of less than 1000 μm, The local thickness is less than 50 μm, and The functional porosity (P f ) is at least 50%.

12. An electrode according to any one of the preceding claims, wherein: The metal member comprises aluminum, The seamless repeating pattern of the non-perforated structural elements comprises primitives of circular depressions and circular protrusions each having a diameter of less than 500 μm and a horizontal distance of less than 1000 μm, The local thickness is less than 100 μm, and The functional porosity (P f ) is at least 50%.

13. A battery comprising at least one electrode according to any one of the preceding claims.

14. An electric device comprising at least one battery according to claim 13.

15. The electric device of claim 14, selected from an electric vehicle for transportation in air, land, water and / or space, a smartphone, a laptop computer, a media player, a power tool, a toy, a heating device, a cooling device and a lighting device.

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