electrodes for energy storage devices

Abstract

Disclosed herein is an anode comprising a current collector and an anode active layer disposed on the current collector, the anode active layer comprising anode active particles, an anode conductive material and an anode binder, wherein the anode binder comprises a copolymer comprising a first repeating unit and a second repeating unit, the first repeating unit comprising an ether bond or derived from the polymerization of a first monomer comprising a plurality of hydroxyl groups, and the second repeating unit derived from the polymerization of an ethylenically unsaturated monomer comprising a hydrophilic pendant group.

Description

[Technical Field]

[0001] (Cross-reference of related applications) This application claims the interests of U.S. Application No. 63 / 453,043, filed on 17 March 2023, which is incorporated herein by reference in its entirety.

[0002] (Field of invention) The present invention relates to energy storage devices, particularly ultracapacitors and lithium-ion batteries, and electrodes used therein. [Background technology]

[0003] Lithium batteries are used in a wide range of products, including medical devices, electric vehicles, airplanes, and consumer products such as laptop computers, mobile phones, and cameras. Due to their high energy density, high operating voltage, and low self-discharge, lithium-ion batteries have overtaken the rechargeable battery market and continue to find new applications in products and evolving industries.

[0004] Generally, a lithium-ion battery (LIB or LiB) comprises an anode, a cathode, and an electrolyte material such as an organic solvent containing a lithium salt. More specifically, the anode and cathode (collectively, the "electrode") are formed by mixing either the anode active material or the cathode active material with a binder and a solvent to form a paste or slurry, which is then coated onto a current collector such as aluminum or copper and dried to form a film on the current collector. The anode and cathode are then layered or coiled before being housed in a pressurized casing containing the electrolyte material, and together they form a lithium-ion battery.

[0005] The binder helps to adhere the active material to the current collector with a suitable coating. It is important that the binder facilitates maintaining sufficient contact between the active material and the current collector. Furthermore, it was crucial to select a binder that is mechanically compatible with the electrode active material so that it can withstand the degree of expansion and contraction of the electrode active material during battery charging and discharging. The binder must also be strong enough to withstand the handling of the electrodes when they are fitted into the battery casing.

[0006] Therefore, binders such as cellulose-based binders or crosslinked polymer binders have been used to provide good mechanical properties. However, in conventional electrodes, the selected binders generally require environmentally unfriendly or toxic solvents for processing. [Overview of the project]

[0007] Disclosed herein is an anode comprising a current collector and an anode active layer disposed on the current collector, the anode active layer comprising anode active particles, an anode conductive material and an anode binder, wherein the anode binder comprises a copolymer comprising a first repeating unit and a second repeating unit, the first repeating unit comprising an ether bond or derived from the polymerization of a first monomer comprising a plurality of hydroxyl groups, and the second repeating unit derived from the polymerization of an ethylenically unsaturated monomer comprising a hydrophilic pendant group.

[0008] Also disclosed herein is an energy storage device comprising a housing, an electrolyte, a first current collector, an anode active material disposed on the first current collector, wherein the anode active material comprises a network of high aspect ratio carbon elements, the network of high aspect ratio carbon elements defining void spaces within the network, a plurality of anode active material particles disposed in the void spaces within the network, and an anode polymer binder, wherein the anode binder comprises a copolymer comprising a first repeating unit and a second repeating unit, the first repeating unit comprising an ether bond or derived from the polymerization of a first monomer comprising a plurality of hydroxyl groups, and the second repeating unit derived from the polymerization of an ethylenically unsaturated monomer comprising a hydrophilic pendant group. An energy storage device comprising: an anode polymer binder; a second current collector; a cathode active material disposed on the second current collector, wherein the cathode active material includes a network of high aspect ratio carbon elements, the network of high aspect ratio carbon elements defining void spaces within the network; a plurality of cathode active material particles disposed in the void spaces within the network, wherein the cathode active material includes a combination of nickel, manganese, and cobalt; and a cathode-to-cathode polymer binder, wherein the polymer binder includes at least one of (i) polyamide, (ii) polyamide copolymer, (iii) polyacrylic acid copolymer, or (iv) polyacrylate copolymer. [Brief explanation of the drawing]

[0009] The following is a brief description of the drawings, where similar elements are similarly numbered and are presented for illustrative purposes only, and not for limiting purposes, the exemplary embodiments disclosed herein. [Figure 1] This is a diagram of an example of an electrode disclosed herein. [Figure 2A] This flowchart shows an example of a method that can be used to fabricate the electrodes disclosed herein. [Figure 2B]A flowchart depicting an exemplary method of manufacturing an anode for an energy storage device. [Figure 3] A depiction of the electrode arrangement within a pouch cell device. [Figure 4] A depiction of a schematic cross-sectional view showing aspects of an energy storage device (ESD). [Figure 5] A graph depicting specific energy versus weight percent of lithiated SiOx fill. [Figure 6] A graph depicting specific energy versus cathode mass loading (areal capacity) for different weight percents of lithiated SiOx fill. **DETAILED DESCRIPTION**

[0010] A more complete understanding of the components, processes, and devices disclosed herein can be obtained by reference to the accompanying drawings. These drawings are only schematic representations based on convenience and ease of demonstration of the present disclosure, and thus are not intended to show the relative sizes and dimensions of the device or its components, and / or to define or limit the scope of the exemplary embodiments. Specific terms are used in the following description for clarity, but these terms are intended to refer only to the specific structures of the embodiments selected for illustration in the drawings and are not intended to define or limit the scope of the present disclosure. It should be understood that in the drawings and the following description, like numeral designations refer to components of like functionality.

[0011] Disclosed herein is an electrolytic cell comprising a housing that includes electrodes (an anode and a cathode). The housing includes an electrolyte that contacts the anode and the cathode. Both electrodes (the anode and the cathode) include a current collector on which an active layer is disposed. The active layer may be disposed on an optional adhesive layer that contacts the electrode.

[0012] This specification discloses an energy storage device comprising a housing in which a cathode, anode, separator, and electrolyte are disposed. The energy storage device may be a rechargeable ultracapacitor, capacitor, battery, etc., capable of supplying energy on demand under a variety of different conditions.

[0013] As detailed below, the cathode comprises a cathode current collector on which a cathode active layer is disposed. The anode comprises an anode current collector on which an anode active layer is disposed. Both the cathode current collector and the anode current collector contain metal. However, the metal is flexible and allows for strain to adapt to the expansion of their respective active layers without being affected by any changes in the collected current. Similarly, the cathode active layer and the anode active layer may undergo dimensional and / or geometric (e.g., shape) changes when subjected to interaction with the electrolyte, temperature and / or pressure changes. While the cathode and anode may undergo dimensional and geometric shape changes, they facilitate a uniform current distribution within the storage device during charging / discharging. This uniform current distribution during charging and discharging reduces the formation of hot spots and, similarly, reduces the formation of dendrites in the active material layers.

[0014] In the embodiment, the storage device comprises high-energy electrodes (cathode and anode) that do not form dendrites. In other words, the distribution of carbonaceous material (carbonaceous particles) and active material (active material particles) in the active layer (distributed on the cathode and anode current collectors) is uniform. There is no separation of the respective active materials (in the cathode active layer and anode active layer) from the carbonaceous material (high aspect ratio carbon elements, activated carbon, carbon black, graphite, carbon fibers, etc. used in each active layer).

[0015] In the embodiments, there is uniformity in the filling of components in each active layer. The carbonaceous material and active material used in the active layer are uniformly spatially distributed on a length scale of greater than 1 micrometer, preferably greater than 5 micrometers, and more preferably greater than 50 micrometers. In the embodiments, the carbonaceous material and active material used in the active layer are uniformly distributed on a length scale of 1 to 1000 micrometers, preferably 10 to 500 micrometers. In other words, there is no difference in density, surface properties, and conductivity along a line drawn through the anode and / or cathode active layers on a length scale greater than 1 micrometer, preferably greater than 5 micrometers. In the embodiments, the density difference along a line drawn through the anode and / or cathode active layers varies by less than 10%, preferably less than 5%, of the average density measured along the same line. The line can be taken in any direction.

[0016] Uniform density in the particle distribution is achieved by using particles that have a uniform particle size and are compatible with each other so as to minimize phase separation of the active material from the carbonaceous material. In the embodiment, the carbonaceous particles and active material particles (used in each active layer) have a particle size of less than 100 nanometers, preferably less than 50 nanometers, and more preferably less than 20 nanometers.

[0017] For high aspect ratio carbonaceous materials (e.g., carbon nanotubes, nanowires, nanorods, etc.), particle size represents the diameter of the particle, not the distance from end to end.

[0018] Using particles with a particle size of less than 100 nanometers (active material particles and carbonaceous particles) allows for a uniform current distribution within the storage device during charging and / or discharging. This reduces the formation of hot spots and, consequently, dendrites in the active layer.

[0019] One method to facilitate a uniform distribution of particles in the active layer is through the compatibilization of carbonaceous particles, active material particles, and an optional binder. Suitable compatibilizers are surfactants or polymer binders.

[0020] Another method for achieving compatibility is by surface functionalization of the active material particles, carbonaceous particles, or both the active material particles and carbonaceous particles. The carbonaceous particles and / or portions of the active material particles may be functionalized with functional groups such as carboxyl groups, carbonyl groups, amine groups, amide groups, thiol groups, sulfonate groups, hydroxyl groups, cyano groups, allyl groups, allenyl groups, norbornyl groups, acrylate groups, methacrylate groups, maleimide groups, maleic anhydride groups, or combinations thereof.

[0021] In the embodiment, the cathode active layer and / or anode active layer comprises two layers having different compositions and densities. The first layer closest to the current collector (and in contact directly or through an adhesive layer) has a first concentration of carbonaceous material and active material, while the second layer disposed on the first layer has a second concentration of carbonaceous material relative to the active material. In the embodiment, the second concentration (of carbonaceous material relative to the active material) exceeds the first concentration (of carbonaceous material relative to the active material). Both the first and second layers have a material with a uniform density throughout their entire volume.

[0022] A separator is disposed between the anode and the cathode and is preferably electrically insulating. It is desirable that the separator be physically flexible and capable of occupying different shapes depending on the shapes of the anode and cathode active layers. In other words, the opposing surfaces of the separator should be able to contact the surfaces of the cathode active layer and the anode active layer, regardless of changes in the shape of the anode or cathode.

[0023] When an electrolyte is added to the storage device, the anode and cathode active layers undergo changes in shape due to the interaction between the electrolyte and the anode and cathode active materials. These shape changes can also be caused by temperature changes during the operation of the storage device. Therefore, it is desirable that the separator undergoes the corresponding shape changes while remaining in contact with the anode and cathode active layers, or alternatively, adapts to these shape changes. In other words, regardless of the operating conditions of the storage device, there is continuous contact simultaneously between the anode surface and the separator, and between the cathode and the separator.

[0024] In exemplary embodiments, simultaneous and continuous contact between the separator and the anode surface, and between the separator and the cathode surface, is achieved by manufacturing the separator from a flexible and easily deformable material. The flexible material used for the separator should preferably expand or contract to maintain continuous contact with the entire surfaces of the anode and cathode active layers, while simultaneously not allowing electrolyte leakage from the anode region of the storage device to the cathode region. Despite the flexibility of the separator, there should be no transport of electrical particles (ions or electrons) across the separator.

[0025] A suitable example of a flexible material for separators is an electrically insulating elastomer. Suitable elastomers include polybutadiene, polyisoprene, styrene-butadiene rubber, poly(styrene)-block-poly(butadiene), poly(acrylonitrile)-block-poly(styrene)-block-poly(butadiene) (ABS), polychloroprene, epichlorohydrin rubber, polyacrylic rubber, silicone elastomer (polysiloxane), fluorosilicone elastomer, fluoroelastomer, perfluoroelastomer, polyether block amide (PEBA), chlorosulfonated polyethylene, ethylene propylene diene rubber (EPR), ethylene-vinyl acetate elastomer, etc., or combinations thereof.

[0026] In embodiments, the separator may include a rigid central region (substrate) on which a flexible layer capable of adapting to geometric changes in the anode active layer and the cathode active layer is disposed on the opposing surface. The rigid central region may include a ceramic or metal completely coated with the flexible layer. The flexible layer is one of the elastomers listed above.

[0027] Examples of ceramic substrates include metal oxides, metal carbides, metal nitrides, metal borides, metal silide, metal oxycarbides, metal oxynitrides, metal boronites, metal carbonitrides, metal boronites, etc., or combinations thereof. Examples of ceramics that can be used as substrates include silicon dioxide, aluminum oxide, titanium dioxide, zirconium dioxide, indium tin oxide, antimony tin oxide, cerium oxide, cadmium oxide, titanium nitride, silicon nitride, aluminum nitride, titanium carbide, silicon carbide, titanium niobium carbide, stoichiometric silicon boride compounds (SiBn, where n=14, 15, 40, etc.) (e.g., silicon triboride, SiB3, silicon tetraboride, SiB4, silicon hexaboride, SiB6, etc.), or combinations thereof.

[0028] Examples of metal oxides include quartz, silica, alumina, titania, zirconia, ceria, or combinations thereof.

[0029] The electrolyte used in the storage device may be a gaseous electrolyte, a liquid electrolyte, or a solid electrolyte. In this embodiment, the electrolyte is a solid electrolyte comprising a polymer material on which an ionic electrolyte is disposed.

[0030] The polymer material used in the electrolyte is an organic polymer selected from a wide variety of thermoplastic polymers, blends of thermoplastic polymers, thermosetting polymers, or blends of thermoplastic and thermosetting polymers. The organic polymer may also be a polymer, copolymer, terpolymer, or a blend of combinations containing at least one of the aforementioned organic polymers. The organic polymer may also be an oligomer, homopolymer, copolymer, block copolymer, alternating block copolymer, random polymer, random copolymer, random block copolymer, graft copolymer, star-shaped block copolymer, dendrimer, polyelectrolyte (polymer having several repeating groups containing an electrolyte), polyamphoteric electrolyte (polyelectrolyte having both cationic and anionic repeating groups), ionomer, or a combination containing at least one of the aforementioned organic polymers. The organic polymer has a number-average molecular weight greater than 10,000 g / mol, preferably greater than 20,000 g / mol, and more preferably greater than 50,000 g / mol.

[0031] Examples of organic polymers include polyacetal, polyacrylic acid, polycarbonate, polyalkyd, polystyrene, polyolefin, polyester, polyamide, polyaramid, polyamideimide, polyarylate, polyurethane, epoxy, phenols, silicone, polyarylsulfone, polyethersulfone, polyphenylene sulfide, polysulfone, polyimide, polyetherimide, polytetrafluoroethylene, polyetherketone, polyetheretherketone, polyetherketoneketone, polybenzoxazole, polyoxadiazole, polybenzothiadinophenothiazine, polybenzothiazole, polypyradinoquinoxaline, polypyromelillimide, polygynoxaline, polybenzimidazole, polyoxyindole, and polyoxoisoin. Examples include dorin, polydioxoisoindorin, polytriazine, polypyridazine, polypiperazine, polypyridine, polypiperidine, polytriazole, polypyrazole, polycarborane, polyoxabicyclononane, polydibenzofuran, polyphthalide, polyacetal, polyanhydride, polyvinyl ether, polyvinyl thioether, polyvinyl alcohol, polyvinyl ketone, polyvinyl halide, polyvinyl nitrile, polyvinyl ester, polysulfonate, polysulfide, polythioester, polysulfone, polysulfonamide, polyurea, polyphosphazene, polysilazane, polypropylene, polyethylene, polyethylene terephthalate, polyvinylidene fluoride, polysiloxane, etc., or combinations containing at least one of the aforementioned organic polymers.

[0032] In the embodiment, the electrolyte is a swollen solid electrolyte comprising one of the aforementioned polymers, a solvent, and an ionic liquid. The solvent and ionic liquid penetrate the solid polymer, causing it to swell and form a gelled solid electrolyte that can penetrate the active layers (anode and cathode) and come into contact with the separator.

[0033] In this embodiment, the electrolyte is very pure and free of impurities.

[0034] In the embodiment, the solid electrolyte is a swollen solid electrolyte comprising a polymer solid, an ionic liquid, and a solvent. The solvent may be present in an amount of 2 to 15% by weight, preferably 3 to 10% by weight, based on the total weight of the solid electrolyte.

[0035] In the embodiment, there are no impurities that can remain in the storage device, particularly in the electrolyte, between the active layer surface and the separator, or between the solid electrolyte surface and the separator.

[0036] Figure 1 is a diagram of an example of an electrode (anode or cathode) disclosed herein. In the example shown, the electrode 100 includes a current collector 102 and an active layer 106. The electrode 100 may optionally include an adhesive layer 104. For example, the adhesive layer 104 includes a material that promotes adhesion between the current collector 102 and the active layer 106. The active layer 106 includes an electrode active material 110 in a binder and a conductive element 108. The conductive element may include a high aspect ratio element.

[0037] The current collector 102 is a conductive element. The current collector may include a metal (e.g., a substantially pure metal or a metal alloy). As another example, the current collector 102 may be in the form of a metal strip or metal foil. For example, the current collector 102 may be an aluminum foil or strip, an aluminum alloy foil or strip, a copper foil or strip, or a copper alloy foil or strip. The current collector 102 may have a thickness of 15 μm (microns) or less, 10 μm or less, 8 μm or less, or 5 μm or less. In some embodiments, the current collector may have a thickness of at least 3 μm at the same time. For example, the current collector 102 may have a thickness of 3 to 15 μm, or 6 μm and about 8 μm. As another example, the current collector 102 is an aluminum foil or aluminum alloy foil with a thickness of 5 to 7 μm.

[0038] The active layer 106 comprises a conductive material, a binder material, and an electrode active material. The active layer can be manufactured by mixing the conductive material, binder material, and electrode active material with a solvent to form a mixture. The mixture can be applied directly to the current collector or applied onto an adhesive layer and bonded to the current collector. If an adhesive layer is used, the adhesive layer may be conductive. The mixture can be dried to remove the solvent, leaving a solid active layer. Hereinafter, the active layers 106 for the anode and cathode are described separately.

[0039] anode As shown above, the anode contains a conductive element, a binder, and an electrode active material, which are mixed together to form a mixture. The mixture is placed on a current collector and dried to form an active layer. The components of the anode active material layer are described in detail below.

[0040] conductive element Conductive elements (also called conductive materials) may contain carbon. For example, a conductive element may be a high-aspect-ratio carbon element. The term "high-aspect-ratio carbon element" refers to a carbonaceous element whose size in one or more dimensions ("long dimensions") is significantly larger than its size in the lateral dimension ("short dimensions"). High-aspect-ratio carbon elements may contain a substantially cylindrical network of carbon atoms. Conductive materials may contain carbon nanotubes or bundles of carbon nanotubes.

[0041] In some embodiments, the conductive material used for the anode may include graphite flakes, which will be discussed later.

[0042] A conductive material can form a conductive penetration network that can transmit electric current between any two isolated points located on the surface of a solid active layer (which does not contain a solvent). In other words, electric current can be transmitted from one surface or end of the active layer to the opposite surface or end of the active layer by physical contact between conductive elements in the electrode active layer or by electron hopping. The penetration network can include voids between high aspect ratio carbon elements that can contain or accommodate the electrode active material. A high aspect ratio conductive material can be substantially oriented in a direction substantially parallel to the current collector within the electrode active layer 106 to facilitate the conduction of electric current from one end to the other of the electrode while still maintaining less orientation throughout the thickness of the active layer.

[0043] The conductive material may be present in the mixture in an amount of 0.1 to 1.3, 0.15 to 1.2, or 0.3 to 1% by weight, based on the total weight of the mixture (the mixture includes the conductive material, electrode active material, binder material, and solvent). The conductive material may be present in the active layer in an amount of 0.2 to 3.5, 0.3 to 3, or 0.5 to 2% by weight, based on the total weight of the solids in the active layer (the total weight of the solids does not include the solvent, but includes the conductive material, binder material, and electrode active material).

[0044] High aspect ratio carbon elements can be single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWNTs), or mixtures of both.

[0045] Single-walled carbon nanotubes can have an outer diameter of 0.5 to 5.0 nanometers, preferably 1.0 to 3.5 nanometers. Single-walled carbon nanotubes can have an aspect ratio (ratio of length to diameter) greater than about 2.0, preferably greater than 5.0, preferably greater than 10.0, greater than 50, and more preferably greater than 100. In exemplary embodiments, single-walled carbon nanotubes can have an average aspect ratio of 5 to 200.

[0046] Single-walled carbon nanotubes can have a length greater than 6 nanometers, preferably greater than 10 nanometers, preferably greater than 15 nanometers, preferably greater than 30 nanometers, preferably greater than 50 nanometers, more preferably greater than 100 nanometers, preferably greater than 1 micrometer, preferably greater than 5 micrometers, preferably greater than 10 micrometers, more preferably greater than 15 micrometers, and at least up to 200 micrometers. In an exemplary embodiment, single-walled carbon nanotubes can have an average length of 10 to 20 micrometers, preferably 20 to 15 micrometers.

[0047] Single-walled carbon nanotubes can be present in a mixture of conductive material, binder material, electrode active material, and solvent in an amount of 0.1 to 0.3% by weight, preferably 0.15 to 0.25% by weight, based on the total weight of the mixture.

[0048] Single-walled carbon nanotubes are present in the electrode active layer (solvent-free conductive material, binder material, and electrode active material) in an amount of 0.2 to 0.6% by weight, preferably 0.3 to 0.5% by weight, based on the total weight of the electrode active layer.

[0049] The number of carbon layers in a multi-walled carbon nanotube can be 2 or more, 5 or more, 10 or more, or 50 or more. On average, a multi-walled carbon nanotube can contain 3 to 15 layers, 4 to 12 layers, 5 to 10 layers, or 6 to 8 layers.

[0050] The active layer 106 may include multi-walled carbon nanotubes and single-walled carbon nanotubes. Multi-walled carbon nanotubes swell more than single-walled carbon nanotubes when wetted with the electrolyte in the energy storage device where the electrode 100 is located. For example, multi-walled carbon nanotubes can swell by at least 15%, at least 25%, or at least 50% more than single-walled carbon nanotubes when wetted with the electrolyte in the energy storage device where the electrode 100 is located. For example, the length of a multi-walled carbon nanotube can expand by at least 15%, at least 25%, or at least 50% more than the length of a single-walled carbon nanotube when wetted with the electrolyte. In another example, a multi-walled carbon nanotube may swell by up to 50% when wetted (e.g., the length of the multi-walled carbon nanotube increases by 50% after wetting with the electrolyte, and / or the diameter of the multi-walled carbon nanotube increases by 50% after wetting).

[0051] Multi-walled carbon nanotubes can have an outer diameter of 2.0–50 nanometers, 5.0–40 nanometers, or 6–10 nanometers. Multi-walled carbon nanotubes can have lengths greater than 10 nanometers, greater than 15 nanometers, greater than 30 nanometers, greater than 50 nanometers, greater than 100 nanometers, greater than 500 nanometers, greater than 1 micrometer, greater than 5 micrometers, greater than 10 micrometers, or greater than 15 micrometers. Simultaneously, multi-walled carbon nanotubes can have an average length of up to 25 micrometers or up to 20 micrometers. In exemplary embodiments, multi-walled carbon nanotubes have an average length of 10–20 micrometers, or 20–15 micrometers. Multi-walled carbon nanotubes can have aspect ratios (ratio of length to diameter) greater than 5.0, greater than 10.0, greater than 50, greater than 100, or greater than 500.

[0052] The electrodes contain multi-walled carbon nanotubes that may be relatively longer than those included in electrodes of related technologies. The use of relatively longer multi-walled carbon nanotubes in electrodes has been found to have beneficial mechanical and / or electrical properties. For example, multi-walled carbon nanotubes provide relatively good output at low densities. As another example, shorter multi-walled carbon nanotubes generally do not swell (e.g., expand) as much as longer multi-walled carbon nanotubes. Therefore, the use of shorter multi-walled carbon nanotubes loses (or reduces) some of the beneficial properties associated with the swelling of carbon nanotubes. As an extreme example, carbon black does not swell because it is simply a collection of carbon particles without entanglement (e.g., the entanglement exhibited by a set of multi-walled carbon nanotubes). The indicator that a certain amount of multi-walled carbon nanotubes has a length exceeding a threshold length and therefore possesses sufficient swelling properties is an observation during the calendering process, and a relatively larger amount of pressure or effort for calendering the slurry in relation to coating it onto foil indicates that the collective swelling (e.g., average swelling) of the multi-walled carbon nanotubes in the active layer meets a certain performance threshold. However, multi-walled carbon nanotubes are generally difficult to process.

[0053] The processing of multi-walled carbon nanotubes related to the preparation / formation of the active layer and / or electrode is milder than the process for electrodes in related technologies. Therefore, the process according to various embodiments maintains longer multi-walled carbon nanotubes (e.g., fewer multi-walled carbon nanotubes are fractured, fragmented, or destroyed). In some embodiments, the active layer of the electrode includes a set of multi-walled carbon nanotubes having an average length longer than the average length of multi-walled carbon nanotubes in electrodes of related technologies. According to various embodiments, the length distribution of the set of multi-walled carbon nanotubes is distorted relative to the nominal length of the multi-walled carbon nanotubes. As an example, the nominal length of the multi-walled carbon nanotubes is approximately 16 microns. For example, the multi-walled carbon nanotubes are processed and / or applied to reduce or minimize fracture or destruction of the multi-walled carbon nanotubes. The length of multi-walled carbon nanotubes in a network of high-aspect-ratio carbon elements is generally the nominal length of the multi-walled carbon nanotubes, or such lengths tend to be more distorted relative to the nominal length. In some embodiments, at least 75% of the multi-walled carbon nanotubes in the network of high-aspect-ratio carbon elements are within 10% of their nominal length (e.g., 13.4 microns to about 15 microns). In some embodiments, at least 75% of the multi-walled carbon nanotubes in the network of high-aspect-ratio carbon elements have a length of at least 12 microns. In some embodiments, at least 75% of the multi-walled carbon nanotubes in the network of high-aspect-ratio carbon elements have a length of at least 13 microns. In some embodiments, at least 50% of the multi-walled carbon nanotubes in the network of high-aspect-ratio carbon elements are within 10% of their nominal length (e.g., 13.4 microns to about 15 microns). In some embodiments, at least 50% of the multi-walled carbon nanotubes in the network of high-aspect-ratio carbon elements have a length of at least 12 microns. In some embodiments, at least 50% of the multi-walled carbon nanotubes in the network of high-aspect-ratio carbon elements have a length of at least 8 microns.In some embodiments, at least 50% of the multi-walled carbon nanotubes in the network of high aspect ratio carbon elements have a length of at least 13 microns.

[0054] According to various embodiments, the length distribution of a set of multi-walled carbon nanotubes is distorted relative to the nominal length of the multi-walled carbon nanotubes. For example, multi-walled carbon nanotubes are treated and / or applied to reduce or minimize the fracturing or breakage of the multi-walled carbon nanotubes. The length of multi-walled carbon nanotubes in a network of high aspect ratio carbon elements is generally the nominal length of the multi-walled carbon nanotube, or the length of such multi-walled carbon nanotubes tends to be more distorted relative to the nominal length.

[0055] In some embodiments, at least 75% of the multi-walled carbon nanotubes in the network of high-aspect-ratio carbon elements are within 10% of their nominal length (e.g., 13.4 micrometers to about 15 micrometers). In some embodiments, at least 75% of the multi-walled carbon nanotubes in the network of high-aspect-ratio carbon elements have a length of at least 12 micrometers. In some embodiments, at least 75% of the multi-walled carbon nanotubes in the network of high-aspect-ratio carbon elements have a length of at least 13 micrometers. In some embodiments, at least 50% of the multi-walled carbon nanotubes in the network of high-aspect-ratio carbon elements are within 10% of their nominal length (e.g., 13.4 micrometers to about 15 micrometers). In some embodiments, at least 50% of the multi-walled carbon nanotubes in the network of high-aspect-ratio carbon elements have a length of at least 12 micrometers. In some embodiments, at least 50% of the multi-walled carbon nanotubes in the network of high-aspect-ratio carbon elements have a length of at least 13 micrometers.

[0056] Multiwalled carbon nanotubes may be present in a mixture (the mixture includes a conductive material, an electrode active material, a binder material, and a solvent or a combination of solvents) in an amount of 0.3 to 1.0% by weight, preferably 0.4 to 0.9% by weight, based on the total weight of the mixture. Multiwalled carbon nanotubes may also be present in a solid anode active layer (the solid active layer does not contain a solvent and includes a conductive material, a binder material, and an electrode active material) in an amount of 0.8 to 2.6% by weight, preferably 1.0 to 1.8% by weight, based on the total weight of the solid anode active material.

[0057] In examples where both multi-walled and single-walled carbon nanotubes are used, the ratio of the weight of multi-walled carbon nanotubes to the weight of single-walled carbon nanotubes in the mixture or solid active material layer may be at least 2:1.

[0058] In one example, a three-dimensional network of high aspect ratio carbon elements 108 contains carbon nanotubes, and these carbon nanotubes are multi-walled carbon nanotubes and / or fragments of such carbon nanotubes.

[0059] In another example, multi-walled carbon nanotubes are present in a mixture or solid anode active material layer in an amount at least twice that of single-walled carbon nanotubes, based on the weight of the conductive material.

[0060] A three-dimensional network of high aspect ratio carbon elements 108 can contain at least 99% by weight of carbon.

[0061] In addition to high aspect ratio carbon elements (carbon nanotubes), the conductive material may optionally include graphite flakes, carbon black, or a combination thereof.

[0062] Graphite flakes are preferably high-aspect-ratio graphite flakes in which at least one dimension is larger than any other dimension. Graphite flakes may be naturally occurring flakes or commercially synthesized flakes. Graphite flakes may be particulate and elliptical in shape. The aspect ratio of these graphite flakes may range from 2:1 to 20:1, preferably 5:1 to 12:1. In embodiments, graphite flakes may be intercalated with metal ions. In another embodiment, graphite flakes may be exfoliated flakes.

[0063] Graphite flakes may be present in the solid anode active layer (the solid active layer is solvent-free and contains a conductive material, a binder material, and an electrode active material) in an amount of 5 to 65% by weight, preferably 8 to 50% by weight, based on the total weight of the solid anode active material.

[0064] In addition to carbon nanotubes, carbon black can also be used. Carbon black is typically used in quantities of 50 square meters / gram (m³). 2 Greater than / gm, preferably 200m 2 Larger than / gm, more comfortable 500m 2 This is a high-surface-area carbon black having a surface area greater than / gm. An example of a high-surface-area carbon black is KELTJEN Black. The carbon black is optional and may be present in the solid anode active layer (the solid active layer does not contain a solvent and contains a conductive material, a binder material, and an electrode active material) in an amount of 0.5 to 2.0% by weight, preferably 0.8 to 1.6% by weight, based on the total weight of the solid anode active material.

[0065] A three-dimensional network of high aspect ratio carbon elements 108 may include an electrically interconnected network of carbon elements exhibiting connectivity above a penetration threshold, where the network defines one or more highly conductive paths having a length greater than 100 μm. The penetration threshold is a threshold that provides a conductive network where conductive elements are in contact with each other and measured across any two points on any surface of the network.

[0066] Anode binder In one embodiment, the anode binder is water-soluble or dispersible in an aqueous solution (e.g., latex). The water-soluble or water-dispersible anode binder comprises a first polymer comprising a first repeating unit containing ether links along a chain skeleton, and / or a polyol. Polymers having ether links along a chain skeleton are typically called polyethers and can be used as binders in the active layer in the form of homopolymers, copolymers, or blends with other compatible homopolymers or copolymers.

[0067] In another embodiment, the anode binder may include a first polymer comprising a first repeating unit containing a polyol. The polyol is an organic compound containing multiple hydroxyl groups. Polyols containing two, three, and four hydroxyl groups are diols, triols, and tetrols, respectively.

[0068] If the anode binder contains a copolymer, the first polymer can be covalently or ionically bonded to a second polymer derived from a second repeating unit containing a (meth)acrylic / (meth)acrylate monomer. Other second polymers (which may be used instead of polymers derived from (meth)acrylic / (meth)acrylate monomers) are also listed below. The anode binder is preferably water-soluble or soluble in aqueous solution. In another embodiment, the anode binder is preferably dispersible in water or aqueous solution.

[0069] The copolymer may be a random copolymer, a block copolymer, an alternating copolymer, a graft copolymer, a star-shaped block copolymer, a gradient copolymer, a dendrimer, or a combination thereof. The copolymer may be a linear polymer, a branched polymer, or may be crosslinked.

[0070] Polyethers that can be used as binders have the structure of formula (1),

[0071] [ka] In the formula, R1 and R2 may independently be hydrogen or an alkyl group having 1 to 5 carbon atoms, n is 1 to 4, and m is 50 to 100,000, preferably 200 to 50,000. An example is a polyoxymethylene having the structure of formula (2).

[0072] [ka] Polyethylene oxide having the structure of formula (3)

[0073] [ka] Polytetramethylene oxide having the structure of formula (4)

[0074] [ka] Polypropylene glycol having the structure of formula (5)

[0075] [ka] Polybutylene glycol having the structure of formula (6)

[0076] [ka] Or combinations thereof, where m has the meaning shown above in formula (1). This combination may include blends or copolymers of the aforementioned structures.

[0077] As shown above, the binder may include a polyol instead of, or in addition to, the polyether. Examples of polyols include the polyether polyols shown below.

[0078] [ka] In the formula, n is 50 to 100,000, preferably 100 to 50,000. Blends of the polyether and polyol described above can also be used.

[0079] The first polymer may have a molecular weight of 1,000 to 1,000,000 grams / mol, preferably 5,000 to 500,000 grams / mol, when measured using a polystyrene standard.

[0080] Other polyols that can be used as binders include polycaprolactone polyols, polyurethanes (obtained by combining polyols with polyisocyanates), polycarbonate polyols, and acrylic polyols.

[0081] In embodiments, the polyethers or polyols described in detail above may be combined with a second repeating unit derived from the polymerization of (meth)acrylic / (meth)acrylate to form copolymers.

[0082] The second repeating unit is derived from the polymerization of an ethylenically unsaturated monomer containing a hydrophilic pendant group. In embodiments, the hydrophilic pendant group is a carboxylic acid group or a carboxylic acid base. The second repeating unit has a structure derived from the polymerization of a monomer represented by formula (7),

[0083] [ka] In the formula, R1 is hydrogen or an alkyl group having 1 to 10 carbon atoms. The carboxylic acid can be neutralized with a metal ion (e.g., sodium, zinc, etc.) to produce a polymer salt (commonly called an ionomer). Examples of polymer acrylics include polyacrylic acid, polymethyl acrylate, polyethyl acrylate, polypropyl acrylate, or combinations containing at least one of the aforementioned acrylates.

[0084] In one embodiment, the second repeating unit is derived from a monomer having a structure represented by formula (8),

[0085] [ka] In the formula, R1 is hydrogen or an alkyl group having 1 to 10 carbon atoms, and R2 is C 1~10 Alkyl, C 3~10 Cycloalkyl, or C 7~10 It is an aralkyl group. Examples of (meth)acrylates include polymethyl methacrylate, polymethyl ethyl acrylate, polymethylpropyl acrylate, polyethyl ethyl acrylate, polymethylaryl acrylate, or any combination containing at least one of the aforementioned acrylates. The term "(meth)acrylate" means that either an acrylate or a methacrylate is intended unless otherwise specified.

[0086] As shown above, acrylics are derived from monomers having at least one fluorine atom substituent and a structure represented by formula (9),

[0087] [ka] In the formula, R1 is hydrogen or an alkyl group having 1 to 10 carbon atoms, and R3 is C 2~10It is a fluoroalkyl group. Examples of compounds having the structure of formula (3) are trifluoroethyl methacrylate and dodecafluoroheptyl methacrylate.

[0088] In embodiments, polyethers and / or polyols are used as a second polymer of non-(meth)acrylic / (meth)acrylate, such as polyacetal, polycarbonate, polyalkyd, polystyrene, polyolefin, polyester, polyamide, polyaramid, polyamideimide, polyarylate, polyurethane, epoxy, phenolic resin, silicone, polyarylsulfone, polyethersulfone, polyphenylene sulfide, polysulfone, polyimide, polyetherimide, polytetrafluoroethylene, polyetherketone, polyetheretherketone, polyetherketoneketone, polybenzoxazole, polyoxadiazole, polybenzothiadinophenothiazine, polybenzothiazole, polypyradinoquinoxaline, polypyromelillimide, polygynoxaline, polybenzoimida It can be reacted with zoles, polyoxyindole, polyoxoisoindoline, polydioxoisoindoline, polytriazine, polypyridazine, polypiperazine, polypyridine, polypiperidine, polytriazole, polypyrazole, polycarborane, polyoxabicyclononane, polydibenzofuran, polyphthalide, polyacetal, polyanhydride, polyvinyl ether, polyvinyl thioether, polyvinyl alcohol, polyvinyl ketone, polyvinyl halogenate, polyvinyl nitrile, polyvinyl ester, polysulfonate, polysulfide, polythioester, polysulfone, polysulfonamide, polyurea, polyphosphazene, polysilazane, polypropylene, polyethylene, polyethylene terephthalate, polyvinylidene fluoride, polysiloxane, etc., or combinations thereof.

[0089] The second polymer, when measured using a polystyrene standard, may have a molecular weight of 1,000 to 1,000,000 grams / mol, preferably 5,000 to 500,000 grams / mol.

[0090] Polyethers and / or polyols can be reacted with acrylics / acrylates (or other second polymers listed above) to form water-soluble copolymer binders. In another embodiment, polyethers and / or polyols can be blended with acrylics / acrylates (or other second polymers listed above) to form water-soluble blends.

[0091] When a polyether and / or polyol is reacted with (meth)acrylic / (meth)acrylate (or any other second polymer listed above) to form a copolymer binder, the polyether and / or polyol is present in an amount of 5 to 95 mole percent, preferably 10 to 90 mole percent, and more preferably 20 to 80 mole percent, based on the total number of moles of the copolymer. The poly(meth)acrylic / poly(meth)acrylate (or any other second polymer listed above) is present in the copolymer in an amount of 95 to 5 mole percent, preferably 90 to 10 mole percent, and more preferably 80 to 20 mole percent, based on the total number of moles of the copolymer.

[0092] Copolymers can be produced by known polymerization techniques for ethylenically unsaturated monomers, such as addition polymerization, condensation polymerization, or ionic polymerization. Polymerization may be, for example, solution polymerization or emulsion polymerization.

[0093] If desired, the polymer may contain crosslinkable functional groups, or a crosslinking agent may be added, thereby crosslinking the binder polymer before the production of the electrode active layer is completed.

[0094] When used in a blend, polyethers and / or polyols are present in amounts of 20 to 80 weight percent (wt%), preferably 30 to 70 wt%, based on the total weight of the blend. Poly(meth)acrylic / poly(meth)acrylates are present in amounts of 80 to 20 wt%, preferably 70 to 30 wt%, based on the total weight of the blend.

[0095] An example of a binder suitable for use in the anode is a water-soluble copolymer of a polyether and polyacrylic acid.

[0096] The water-soluble or water-dispersible binder may be present in the anode mixture in an amount of 3 to 12 wt% based on the total weight of the dry anode active material (absence of solvent). The binder may be present in an amount of 5 to 10 wt% based on the total weight of the dry anode active material (absence of solvent).

[0097] Anode active material For example, the anode active material can be silicon (Si), germanium (Ge), tin (Sn), lead (Pb), antimony (Sb), bismuth (Bi), zinc (Zn), aluminum (Al), titanium (Ti), nickel (Ni), cobalt (Co), cadmium (Cd); alloys thereof, or two or more of these, or alloys of these with other elements; oxides, carbides, nitrides, sulfides, phosphides, selenides, and tellurides of these metals, and mixtures or lithium-containing composites thereof; salts and hydroxides of Sn; lithium titanate, lithium manganate, lithium aluminate, lithium-containing titanium oxide, lithium transition metal oxide; their prelithiated forms; particles of Li, Li alloy, or surface-stabilized Li having at least 60 wt% lithium, or combinations thereof. The active material can include graphite instead of, or in addition to, the anode active material. As an example, the anode active material can include silicon oxide and / or carbon silicon oxide. Such an anode active material containing silicon oxide or carbon silicon oxide can further include graphite.

[0098] In an embodiment, the active material used in the anode is a lithium-based active material. An example of a lithium-based active material is Li x Si y O zHere, x is 1 to 15, preferably 2 to 7, y is 0 to 4, preferably 1 or 2, and z is 0 to 9, preferably 1 to 5. SiO is synthesized by mixing silicon and silica in a 1:1 molar ratio, and then sublimating the mixture to collect amorphous SiO (a-SiO) material. Because the silicon atoms in a-SiO are randomly distributed, their valence numbers can be 0, 1+, 2+, 3+, and 4+ depending on the bonding conditions with different numbers of oxygen atoms. Some of the silicon atoms aggregate to form tiny silicon crystals surrounded by other amorphous material, which have Si-O bonds with different silicon valences. In LIB, these tiny silicon crystals in a-SiO react with Li+ ions, and Li 15 It forms Si4 and functions as an active material for energy storage. Due to the nanoscale silicon crystals, no pulverization is performed after lithiation. Therefore, good reversibility can be obtained.

[0099] Examples of lithium-based active materials include Li 15 Examples include Si4, Li2SiO3, Li2Si2O5, Li6Si2O7, Li4SiO4, Li2O, or combinations thereof.

[0100] In the embodiment, the lithium-based active material can be blended with a carbonaceous material to form a Li-SiOx-C active material. In other words, the active material may include lithium, silicate, and carbon. Carbon in the form of carbon black, carbon nanotubes, or graphite, Li x Si y O z (Here, the x, y, and z values ​​are detailed above) may be blended and ground to form aggregates and granules of Li-SiOx-C active material.

[0101] In the production of Li-SiOx-C active material, elemental silicon (Si) can first be reacted with a silicate material (SiOx) and blended. The silicon-silica combination is subjected to a reaction and grinding process to produce a powder. Carbon is added to this powder in a carbon coating process, and lithium is added in a lithium doping process. After the carbon and lithium doping processes, the formed Li-SiOx-C material enters a classification process to form the final usable anode active material called Li-SiO with a carbon coating. The relative density of the formed material is approximately 2.1 g / cm³ at 25°C. 3 It is possible that this is the case.

[0102] In the embodiment, the energy storage device may have an initial charge ratio capacity of 1500 to 1600 mAh / g, preferably 1400 to 1500 mAh / g, with an initial Coulomb efficiency of 90 to 94%, and preferably 1350 to 1400 mAh / g with an initial Coulomb efficiency of 87 to 89%.

[0103] Lithium can be added in elemental form or in compound form. Some of these lithium compounds are listed herein. The D50 particle size of the Li-SiOx-C particles prepared in this way is 6 to 9 micrometers. The BET surface area of ​​the formed Li-SiOx-C material is 3 to 4 m² based on the total weight of the Li-SiOx-C active material, with a carbon content of 3 to 4 wt%. 2 It may be / g. Li / Li in a cell (also called an energy storage device) having a Li-SiOx-C anode. + The initial charge ratio capacity for 5mV relative to Li / Li+ can be 1500-1600mAh / g, the initial discharge ratio capacity for 2.0V relative to Li / Li+ of a cell with Li-SiOx-C anode material can be 1400-1500mAh / g with an initial Coulomb efficiency of 90-94%, and the initial discharge ratio capacity for 1.0V relative to Li / Li+ of a cell with Li-SiOx-C material can be 1350-1400mAh / g with an initial Coulomb efficiency of 87-89%.

[0104] The production of Li-SiOx and Li-SiOx-C active materials, as well as the corresponding electrodes, are described in detail in U.S. Patent No. 9,825,290(B2) and U.S. Patent Application Publication No. 2019 / 0237761(A1), the entire contents of which are incorporated by reference.

[0105] The anode active material may be present in the anode active layer in an amount of 40-90% by weight, based on the total weight of the anode active layer (without solvent).

[0106] Preparation of A An anode can first be produced by preparing a mixture (sometimes called a slurry) of conductive elements, active material, and binder in a solvent or solvent mixture. The method used to produce an anode can also be used to produce a cathode. For brevity, this method is not repeated during the production of the cathode. The advantage of binders such as those described herein is that a useful slurry can be formed using water, alcohol, or a combination thereof as the solvent. The slurry can then be coated directly onto a current collector or applied to a current collector having an intermediate adhesive layer.

[0107] The slurry can be prepared in a single step. Alternatively, the slurry can be prepared according to a multi-step process, such as the one shown in the flowchart of Figure 2A illustrating an example of a process 600 for providing with respect to electrode 100 in Figure 1. Figure 2B illustrates another mode for manufacturing an anode for an energy storage device. In 610, a conductive material, e.g., a high aspect ratio carbon element, and a surface treatment material (e.g., a surfactant, a binder material as described herein, or both) are combined with a solvent (e.g., water, alcohol, or a combination thereof) to form an initial slurry.

[0108] In the 620, the initial slurry is treated to ensure good dispersion of the solid material in the slurry. This treatment may involve introducing mechanical energy into the mixture of solvent and solid material (e.g., using an ultrasonic treatment device which may be referred to as a "sonifier"), or into another suitable mixing device (e.g., a high-shear mixer). For example, the mechanical energy introduced into the mixture may be at least 0.4 kilowatt-hours / kilogram (kWh / kg), 0.5 kWh / kg, 0.6 kWh / kg, 0.7 kWh / kg, 0.8 kWh / kg, 0.9 kWh / kg, 1.0 kWh / kg, or greater. For example, the mechanical energy introduced into the mixture per kilogram of the mixture may be in the range of 0.4 kWh / kg to 1.0 kWh / kg, or any sub-range thereof, such as 0.4 kWh / kg to 0.6 kWh / kg.

[0109] As one example, an ultrasonic bath mixer may be used. As another example, a probe sonicator may be used. Probe sonication can be significantly more powerful and effective compared to ultrasonic baths for nanoparticle applications. The high shear force generated by ultrasonic cavitation has the ability to break down particle aggregates, resulting in smaller and more uniform particle sizes. In particular, sonication can result in a stable and homogeneous suspension of solids in a slurry. Generally, this results in the dispersion and de-aggregation of solids as well as other decompositions. An example of a probe sonication device is the Q Series Probe Sonicator, available from QSonica LLC (Newtown, Connecticut). Another example is the Branson Digital SFX-450 sonicator, commercially available from Thomas Scientific (Swedesboro, New Jersey).

[0110] The localized nature of each probe within a probe assembly can sometimes lead to heterogeneous mixing and suspension. This can occur, for example, with large samples. This can be addressed by using a continuous flow cell and a setting with appropriate mixing. For example, in such a setting, the slurry mixing achieves a reasonably homogeneous dispersion.

[0111] The initial slurry, once processed, may have a viscosity in the range of 5,000 cps to 25,000 cps or any sub-range thereof, for example, 6,000 cps to 19,000 cps.

[0112] In an optional step 630 (for example, used if no binder was added in step 610), a binder or additional binder may be applied so that the surface treatment can be fully or partially formed on the conductive material (e.g., high aspect ratio carbon elements) in the initial slurry. In some embodiments, the surface treatment may self-assemble at this stage.

[0113] The resulting surface treatment may include functional groups or other features that can promote adhesion between high aspect ratio carbon elements and active material particles, as described in the following further steps. For example, functional groups on the binder can provide the aforementioned surface treatment.

[0114] In 640, the active material particles can be combined with the initial slurry to form a final slurry containing the active material particles, along with high aspect ratio carbon elements formed on top of the surface treatment.

[0115] The active material can be added directly to the initial slurry. Alternatively, the active material may first be dispersed in a solvent (e.g., water, alcohol, or a combination thereof, using the techniques described above for the initial solvent) to form an active material slurry. This active material slurry can then be combined with the initial slurry to form the final slurry.

[0116] Suitable solvents are water, alcohol, or a combination thereof. Examples of alcohols include ethanol, methanol, propanol, butyl alcohol, ethylene glycol, propylene glycol, or a combination thereof. In addition to water and alcohol, other solvents may be added to facilitate the solubilization and / or dispersion of the polymer. Other solvents include polar solvents and nonpolar solvents. The addition of other solvents should preferably not alter the solubility of the polymer in water or alcohol. Liquid aprotic polar solvents, such as propylene carbonate, ethylene carbonate, butyrolactone, acetonitrile, benzonitrile, nitromethane, nitrobenzene, sulfolane, dimethylformamide, N-methylpyrrolidone, or a combination thereof, may be added to water or alcohol for the dissolution of the polymer. Polar protic solvents, such as acetonitrile, nitromethane, acetone, dimethyl sulfoxide, dimethylformamide, or a combination thereof, may also be used. Other nonpolar solvents, such as benzene, toluene, methylene chloride, carbon tetrachloride, hexane, diethyl ether, tetrahydrofuran, or combinations thereof, may also be used. Cosolvents comprising at least one aprotic polar solvent and at least one nonpolar solvent may also be used to modify the solubilizing power of the solvent.

[0117] When water and alcohol are used as solvents for the anode active layer (used in the anode), the ratio of water to alcohol is 80:20 to 95:5, preferably 88:12 to 92:8. In exemplary embodiments, the ratio of water to alcohol is 90:10.

[0118] The solvent may be added to the mixture of the binder, conductive material, and active material in an amount of 10 to 1000% by weight, preferably 50 to 500% by weight, and more preferably 100 to 200% by weight, of the total weight of the solids used to form the active layer. The solids include materials (e.g., binder, conductive material, and active material) that do not evaporate and become an active material layer disposed on the current conductor.

[0119] In 650, the final slurry is treated to ensure good dispersion of solid materials in the final slurry. Any suitable mixing process known in the art may be used. For example, this treatment may use the techniques described above, with reference to 620. Alternatively, a planetary mixer, such as a multi-axis (e.g., three or more axes) planetary mixer, may be used. The planetary mixer may feature multiple blades, such as two or more mixing blades and one or more (e.g., two, three, or more) dispersion blades, such as two or more mixing blades and disk dispersion blades.

[0120] During this time, the interaction between the surface treatment (e.g., a binder) and the active material facilitates the self-assembly process, so that the matrix entangling the active material can self-assemble completely or partially.

[0121] In some embodiments, the final slurry, once processed, has a viscosity in the range of 1,000 cps to 10,000 cps or any sub-range thereof, for example, 2,500 cps to 6,000 cps.

[0122] In 660, the active layer 106 is formed from the final slurry. In some embodiments, the final slurry may be wet-cast directly onto the current collector conductive layer 102 (or an optional adhesive layer 104) and dried. As an example, the casting may form the active layer 106 by applying at least one of heat and high pressure until substantially all of the solvent and any other liquids are removed. It may be desirable to protect various parts of the underlying layers. For example, protecting the underside of the conductive layer 102 may be desirable if the electrode 100 is intended to operate on one side. Protection may include, for example, protection from the solvent by masking a particular area, or providing a drain for removing the solvent.

[0123] In another example, the final slurry may be at least partially dried elsewhere using any suitable technique (e.g., roll-to-roll layer application) and then transferred onto the adhesive layer 104 or conductive layer 102 to form the active layer 106. In yet another example, the combined wet slurry may be placed on an intermediate material having a suitable surface and dried to form a layer (e.g., the active layer 106). Any material having a suitable surface can be used as the intermediate material, but exemplary intermediate materials include polytetrafluoroethylene (PTFE) because its properties facilitate subsequent removal from the surface. The layer may be formed by pressing to provide a layer exhibiting the desired thickness, area, and density.

[0124] In yet another example, the final slurry may be formed into a sheet and appropriately coated onto the adhesive layer 104 or the conductive layer 102. For example, the final slurry can be applied through a slot die to control the thickness of the applied layer. In another example, the slurry may be applied and then flattened to a desired thickness, for example, using a doctor blade. Various other techniques can be used to apply the slurry. For example, coating techniques include, but are not limited to, comma coating, comma reverse coating, doctor blade coating, slot die coating, direct gravure coating, air doctor coating (air knife), chamber doctor coating, offset gravure coating, one-roll kiss coating, reverse kiss coating with small-diameter gravure rolls, bar coating, three-reverse-roll coating (top feed), three-reverse-roll coating (fountain die), and reverse-roll coating.

[0125] The viscosity of the final slurry can vary depending on the applied technique. For example, in the case of comma coating, the viscosity may range from approximately 1,000 cps to approximately 200,000 cps. Lip die coating provides coating with a slurry exhibiting a viscosity of approximately 500 cps to approximately 300,000 cps. Reverse kiss coating provides coating with a slurry exhibiting a viscosity of approximately 5 cps to 1,000 cps. In some applications, each layer may be formed by multiple passes.

[0126] If desired, the active layer 106 formed from the final slurry can be compressed (for example, using a calendering apparatus) before or after it is applied to the electrode 100. The slurry can be partially or completely dried (for example, by applying heat, high pressure, or a combination thereof) before or during the compression process. For example, in some embodiments, the active layer can be compressed to a final thickness (for example, in the direction perpendicular to the current collector layer 102) of 90%, 80%, 70%, 50%, 40%, 30%, less than 20%, or 10% of its thickness before compression.

[0127] If a partially dried layer is formed during the coating or compression process, the layer can then be completely dried (for example, by applying heat, high pressure, or a combination thereof). In some embodiments, substantially all of the solvent is removed from the active layer 106.

[0128] The solvent used to form the slurry is recovered and recycled into the slurry preparation process.

[0129] The active layer 106 can be compressed to increase the surface area of ​​each layer, for example, by destroying some of the high aspect ratio carbon elements or other carbonaceous materials that constitute its components. This compression process can increase one or more of the following: interlayer adhesion, intralayer ion transport rate, and layer surface area. In various embodiments, compression can be applied before or after each layer is applied to or formed on the electrode 100.

[0130] When calendering is used to compress the active layer 106, the calendering apparatus can be set with gap intervals equal to 90%, 80%, 70%, 50%, 40%, 30%, less than 20%, or less than 10% of the thickness of the layer before compression (for example, set to about 33% of the thickness of the layer before compression). The calender roll can be configured to provide a suitable pressure, for example, more than 1 ton per 1 cm of roll length, more than 1.5 tons per 1 cm of roll length, more than 2.0 tons per 1 cm of roll length, more than 2.5 tons per 1 cm of roll length, or greater. The compressed active layer can have a density in the range of 1 g / cc to 10 g / cc, or any sub-range such as 2.0 g / cc to 4.0 g / cc. The density of the cathode active layer is 2 to 4 g / cc. The anode active layer generally has a density of 1.0 to 1.8 g / cc. The calendering process can be carried out at temperatures in the range of 20°C to 140°C or any partial range thereof. In some embodiments, the active layer 106 may be preheated before calendering, for example, at temperatures in the range of 20°C to 100°C or any partial range thereof.

[0131] Process 600 may include any of the following features (individually or in any preferred combination):

[0132] The initial slurry has a solid content ranging from 0.1% to 20.0% by weight (or any sub-range thereof), and / or the final slurry has a solid content ranging from 10.0% to 80% by weight (or any sub-range thereof).

[0133] As shown, the conductor and binder scaffold or matrix can hold active material particles together and form an aggregated layer that adheres strongly to the metal current collector. Such an active material structure can be created during slurry preparation, followed by a roll-to-roll ("R2R") coating and drying process. One of the main advantages of this technique is its scalability and "drop-in" nature, as various embodiments can be adapted to conventional electrode manufacturing processes.

[0134] The matrix can be formed during slurry preparation using the techniques described herein, and the high aspect ratio carbon material is appropriately dispersed and, if desired, chemically functionalized using, for example, process 600 in Figure 2 as described above. The chemical functionalization is designed to form an organized self-assembled structure having a surface of active material particles, e.g., NMC particles (detailed below) for use in the cathode, or in the case of the anode, silicon particle ("Si") particles or silicon oxide ("SiOx") particles. The slurry thus formed can be based on water and / or an alcohol solvent for the cathode and water for the anode, such solvents evaporate very easily during the manufacturing process and are easy to handle. Electrostatic interactions promote the self-assembled structure in the slurry, and after the drying process, the bonding between the carbon matrix with the thus formed active material particles and the surface of the current collector is promoted by surface treatment (e.g., functional groups on the matrix) and strong entanglement of the active material in the carbon matrix.

[0135] The mechanical properties of the electrodes can be modified according to the application and mass filling requirements by adjusting the surface functionalization versus entanglement effect.

[0136] After coating and drying, the electrodes can undergo a calendering step to control the density and porosity of the active material. NMC cathode electrodes can achieve a density of 3.5 g / cc or higher and a porosity of 20% or higher. Porosity can be optimized according to mass filling and lithium-ion battery cell requirements. For silicon oxide or silicon-based anodes, porosity can be specifically controlled to accommodate the expansion of the active material during the lithiation process.

[0137] The teachings herein may provide a reduction of up to 20% in $ / kWh. By using water, alcohol, or a water / alcohol mixture as the solvent, these solvents evaporate easily, allowing for higher throughput in electrode manufacturing and, more importantly, significantly reducing energy consumption from long drying cycles. Conventional recovery systems required when using NMP or similar compounds as solvents are also greatly simplified when using water, alcohol, or a combination thereof.

[0138] The teachings herein provide an active layer having a 3D matrix that can dramatically increase electrode conductivity by 10 to 100 times compared to electrodes using conventional binders such as PVDF, enabling rapid charging at the battery level. This technique enables thick electrode coatings on the cathode of up to 150 μm per side (or more) of the current collector. The solvent used in the slurry in combination with the strong 3D carbon matrix is ​​designed to achieve a thick wet coating without cracking during the drying step. A thick cathode with a high-capacity anode enables a substantial leap in energy density, reaching over 400 Wh / kg.

[0139] Cathode As shown above, the cathode comprises a cathode conductive element, a cathode binder, and a cathode active material, which are mixed together to form a mixture. The mixture is placed on a current collector and dried to form an active layer. The components of the cathode active material layer are described in detail below.

[0140] Cathode conductive element The cathode conductive element may contain carbon nanotubes arranged to form a permeable network with voids. The cathode active material is located in the voids of the permeable network. The cathode conductive material is similar to that described above for the anode conductive material.

[0141] Cathode binder A cathode comprises one or more polymer binders (cathode polymer binders), one or more active materials, and a conductive material. The one or more polymer binders, one or more active materials, and the conductive material are blended with a solvent to form a cathode mixture. The cathode mixture is then placed on a current collector (typically a metal) and dried to form a solid cathode active layer.

[0142] The cathode polymer binder (used in the cathode) includes a first cathode polymer binder comprising a polyamide, a polyacrylic acid copolymer, or an acrylate copolymer. The cathode polymer binder (used in the cathode) also includes a second cathode polymer binder comprising polyvinylpyrrolidone (PVP).

[0143] The polyamide (used as the first cathode polymer binder) may include aliphatic polyamides, aromatic polyamides, or combinations thereof. In one embodiment, the polyamide includes a general family of resins known as nylon, characterized by the presence of an amide group (-C(O)NH-). Any amide-containing polymer can be used individually or in combination. Nylon-6 and nylon-6,6 are preferred polyamide resins available from various commercial sources. However, other polyamides such as nylon-4, nylon-4,6 (PA 46), nylon-12, nylon-6,10, nylon-6,9, nylon-6,12, nylon-9T, copolymers of nylon-6,6 and nylon-6, nylon-610 (PA 610), nylon-11 (PA 11), nylon-12 (PA 12), nylon-6-3-T (PA 6-3-T), polyarylamide (PA MXD 6), polyphthalamide (PPA) and / or polyether block amide, as well as other polyamides such as amorphous nylon, may also be useful. Mixtures of various polyamides and various polyamide copolymers are also useful.

[0144] Polyamides can be obtained by several well-known processes, such as those described in U.S. Patents 2,071,250, 2,071,251, 2,130,523, 2,130,948, 2,241,322, 2,312,966, and 2,512,606. For example, nylon-6 is a polymerization product of caprolactam. Nylon-6,6 is a condensation product of adipic acid and 1,6-diaminohexane. Similarly, nylon 4,6 is a condensation product of adipic acid and 1,4-diaminobutane. In addition to adipic acid, other diacids useful for the preparation of nylon include azelaic acid, sebacic acid, dodecanediic acid, and terephthalic acid and isophthalic acid. Other useful diamines include, in particular, m-xylenediamine, di-(4-aminophenyl)methane, di-(4-aminocyclohexyl)methane; 2,2-di-(4-aminophenyl)propane, and 2,2-di-(4-aminocyclohexyl)propane. Copolymers of caprolactam with diacids and diamines are also useful.

[0145] Polyamides are generally derived from the polymerization of organic lactams having 4 to 12 carbon atoms. In one embodiment, the lactam is represented by formula (I),

[0146] [ka] In the formula, n is between 3 and 11. In one embodiment, the lactam is an epsilon-caprolactam where n is equal to 5.

[0147] Polyamides can also be synthesized from amino acids having 4 to 12 carbon atoms. In one embodiment, the amino acid is represented by formula (II),

[0148] [ka] In the formula, n is 3 to 11. In one embodiment, the amino acid is epsilon-aminocaproic acid, where n is equal to 5. Polyamides can also be polymerized from aliphatic dicarboxylic acids having 4 to 12 carbon atoms and aliphatic diamines having 2 to 12 carbon atoms. In one embodiment, the aliphatic diamine is of formula (III)H2N-(CH2) n In the formula -NH2(III), n is approximately 2 to approximately 12. In one embodiment, the aliphatic diamine is hexamethylenediamine (H2N(CH2)6NH2). In one embodiment, the molar ratio of dicarboxylic acid to diamine is 0.66 to 1.5. Within this range, a molar ratio of 0.81 or higher is generally beneficial. In another embodiment, the molar ratio is 0.96 or higher. In yet another embodiment, the molar ratio is 1.22 or lower. In yet another embodiment, the molar ratio is 1.04 or lower. Examples of polyamides useful in the present invention include nylon 6, nylon 6,6, nylon 4,6, nylon 6,12, nylon 10, or combinations containing at least one of the polyamides described above.

[0149] Those copolymers of poly(meth)acrylic acid / poly(meth)acrylate are listed and described above, and for brevity, will not be repeated here.

[0150] The first cathode polymer binder is present in an amount of 0.1 to 0.4% by weight, preferably 0.15 to 0.375% by weight, based on the weight of the cathode mixture (which includes the cathode polymer binders (first and second cathode polymer binders), the cathode active material, the cathode conductive material, and the solvent). The first cathode polymer binder is present in the cathode active layer in an amount of 0.2 to 0.5% by weight, preferably 0.25 to 0.45% by weight, based on the total weight of the cathode active layer.

[0151] The cathode active layer contains a second cathode polymer binder, which includes polyvinylpyrrolidone (PVP). In addition to functioning as a second cathode polymer binder, PVP can also function as a dispersant for the cathode active material and the cathode conductive filler.

[0152] The second cathode polymer binder is present in an amount of 0.1 to 0.4% by weight, preferably 0.15 to 0.375% by weight, based on the weight of the cathode mixture (which includes the cathode polymer binders (first and second cathode polymer binders), cathode active material, cathode conductive material, and solvent). The second cathode polymer binder is present in the cathode active layer in an amount of 0.2 to 0.5% by weight, preferably 0.25 to 0.45% by weight, based on the total weight of the cathode active layer.

[0153] Cathode active material The cathode active material may contain lithium cobalt oxide (LCO, sometimes called "lithium cobaltate" or "lithium cobaltite"). Examples of LCO formulations include LiCoO2, lithium nickel manganese cobalt oxide (NMC, with variations of LiNiMnCo), lithium manganese oxide (LMO, such as LiMn2O4, Li2MnO3, or variations of combinations thereof), and lithium titanate oxide (LTO, one variation of which is Li4Ti5O 12 This may include lithium iron phosphate oxide (LFP, one variant being LiFePO4), lithium nickel cobalt aluminum oxide (and its variant as NCA), as well as other similar materials. Other variants of those mentioned above may be included.

[0154] In the embodiment, the cathode active material may include NMC, NCA, NCMA, or a combination thereof.

[0155] When NMC is used as a cathode active material, nickel-rich NMC may be used. For example, a variation of NMC is LiNi x Mn y Co (1-x-y)This is possible, where x is approximately 0.7 or greater, 0.75 or greater, 0.80 or greater, 0.85 or greater, y is 0.1 or greater, 0.15 or greater, 0.2 or greater, or 0.25 or greater, and x+y is less than 1. For example, NMC811, where x is approximately 0.8 and y is approximately 0.1, can be used. Alternatively, the cathode active material may be lithium nickel manganese cobalt oxide (LiNi x Mn y Co z It may include O2). Variations of this formula that can be used in the active material layer are NMC111 (detailed below), NMC532 (LiNi 0.5 Mn 0.3 Co 0.2 O2), NMC622 (LiNi 0.6 Mn 0.2 Co 0.2 O2), or combinations thereof.

[0156] In the embodiment, NMC91 can be used as a cathode active material. NMC91 contains 91 mole percent or more nickel. An example of NMC91 is LiNi 0.91 Co 0.06 Mn 0.03 It is O2. Also, as the cathode active material, Li[Ni 1-x-y Co x Al y O2(NCA) may be used. An example of NCA is NCA89.

[0157] In yet another embodiment, the cathode active material may be an NCMA material. An example of an NCMA is Li[Ni], also known as NCMA89. 0.89 Co 0.05 Mn 0.05 Al 0.01 It is 2O2.

[0158] In embodiments, the cathode active material may also include a nickel-rich combination of nickel, manganese, and cobalt. Lithium-nickel-manganese-cobalt oxide (LiNiMnCoO2), abbreviated as NMC, provides the high overall performance, excellent specific energy, and lowest self-heating rate of all mainstream cathode powders. NMC powder may contain 20–40 wt% nickel, 20–40 wt% manganese, and 20–40 wt% cobalt, based on the total weight of the NMC blend. While the term “NMC powder” can refer to various blends, it is preferable to use a blend containing 33 wt% nickel, 33 wt% manganese, and 33 wt% cobalt. This blend, sometimes referred to as 1-1-1 (NMC111), is useful for applications using frequent cycles (automotive, energy storage) due to the reduced material cost resulting from the lower cobalt content and the nickel-rich combination of nickel, manganese, and cobalt (NMC). NMC powder may contain 20–40 wt% nickel, 20–40 wt% manganese, and 20–40 wt% cobalt, based on the total weight of the NMC blend. While the term “NMC powder” can refer to various blends, it is preferable to use a blend containing 33 wt% nickel, 33 wt% manganese, and 33 wt% cobalt. This blend, sometimes referred to as 1-1-1, is useful for applications with frequent cycles (automotive, energy storage) due to the reduced material cost resulting from its lower cobalt content. Lithium-nickel-manganese-cobalt oxide (LiNiMnCoO2) provides the high overall performance, excellent specific energy, and lowest self-heating rate of all mainstream cathode powders. Lithium-rich NCM materials such as 424 and 523, manufactured by BASF, can also be used as cathode active materials.

[0159] Generally, increasing the amount of active material added to the cathode (measured as a function of the total weight of the cathode) increases the area capacity and specific energy levels in the cathode.

[0160] As shown above, the cathode active material can be contained or contained within a network of high aspect ratio conductive materials present in the cathode active layer. The cathode active material may be present in the mixture used to form the cathode in an amount of 55-75% by weight, preferably 60-70% by weight, based on the total weight of the cathode mixture (a mixture used to produce a cathode active layer containing a cathode binder material, cathode active material, cathode conductive material, and solvent). The cathode active material may be present in the cathode active layer (solvent-free) in an amount of 95-98.5% by weight, based on the total weight of the cathode active layer.

[0161] Production of the cathode active layer The cathode active layer is disposed on the current collector. The cathode active layer is manufactured in the same manner as the anode active layer. A cathode binder, cathode active material, and cathode conductive material are mixed with a solvent to form a slurry. The slurry is disposed on the cathode current collector. The solvent is evaporated, and the cathode current collector is subjected to further finishing operations in a roll mill to produce the cathode, which can then be used in an energy storage device as detailed below.

[0162] Energy storage devices Once the electrode 100 is assembled, it can be used to assemble an energy storage device. The assembly of the energy storage device may follow conventional steps used to assemble the electrode with a separator and place it in a housing such as a canister or pouch, and may further include additional steps for adding an electrolyte and sealing the housing.

[0163] One exemplary embodiment includes a pouch-cell type Li-ion battery energy storage device combining a Ni-rich NMC active material in the cathode with an SiOx and graphite blend active material in the anode, both of which are fabricated using a 3D carbon matrix process as described herein.

[0164] A schematic diagram of the electrode arrangement in an example of a pouch cell device is shown in Figure 3. As shown, cathode active layers 760 (e.g., active layers according to various embodiments disclosed herein) on both sides of a current collector 710 (e.g., an aluminum foil current collector) form a double-sided cathode disposed between two single-sided anodes. Each single-sided anode has an anode layer 740 or 750 (e.g., an active layer including a network of carbon elements, as disclosed herein) disposed on a current collector 720 or 730 (e.g., a copper current collector). The electrodes are separated by a permeable separator material 780 wetted with an electrolyte (not shown). This arrangement can be housed in a pouch cell of a type well known in the art.

[0165] Figure 4 shows a cross-section of an energy storage device (ESD) 810. The energy storage device (ESD) 810 includes a housing 811. The housing 811 has two terminals 800 disposed on its exterior. The terminals 800 provide internal electrical connections to a storage cell 812 housed within the housing 811 and external electrical connections to external devices such as a filling or charging device (not shown). Energy storage devices disclosed herein may include batteries, capacitors, ultracapacitors, and the like. [Examples]

[0166] This embodiment is performed to determine the effect of the Li-SiOx-C anode packing amount on cathode performance and, therefore, cell performance. The cathode packing is 4.0~7.0 mAh / cm². 2The analysis is performed using (area capacity). Figure 5 is a graph illustrating the specific energy as a percentage of weight of Li-SiOx-C filling. The effect of Li-SiOx-C filling amount on specific energy was examined for filling amounts from 0 to 95 wt%. From Figure 5, it can be seen that the specific energy increases as the Li-SiOx-C filling amount increases from 0 wt% to approximately 65 wt%. It can also be observed that the specific energy increases with area capacity. Figure 6 is a graph illustrating the specific energy as a percentage of weight of different Li-SiOx-C fillings as a percentage of cathode mass filling (area capacity). Figure 6 shows that an increase in the Li-SiOx-C content in the cathode results in an increase in specific energy (measured in watts-hours / kilogram (Wh / Kg)).

[0167] Table 1 below shows the cell (energy storage device) performance of a cell containing a cathode with NCM-91 and an anode with a graphite-SiOx blend (containing 35 wt% graphite and 65 wt% SiOx). The cathode performance is 3.4–3.6 g / cm³. 3 It has a density of 1.45-1.60 g / cm³, and the anode has a density of 1.45-1.60 g / cm³. 3 It has a density of .

[0168] [Table 1]

[0169] As can be seen from Table 1, the cell (also called an energy storage device) exhibits a specific energy of 300–450 watt-hours / kilogram (Wh / kg), preferably 340–400 Wh / kg, and more preferably 360–395 Wh / kg. The cell exhibits an energy density of 900–1000 watt-hours / liter (Wh / L), preferably 930–995 Wh / L, and more preferably 940–990 Wh / L. The initial Coulombic efficiency (ICE) of the cell is in the range of 0.87–0.91, preferably 0.89–0.90.

[0170] All ranges disclosed herein include endpoints, which can be combined independently of each other (for example, the range “up to 25% by weight, or more specifically, 5% to 20% by weight” includes the endpoints and all intermediate values ​​of the range “5% to 25% by weight”, etc.). Furthermore, the upper and lower limits described may be combined to form a range (for example, “at least 1 or at least 2% by weight” and “up to 10 or 5% by weight” may be combined as the range “1 to 10% by weight”, or “1 to 5% by weight”, or “2 to 10% by weight”, or “2 to 5% by weight”).

[0171] This disclosure may, alternatively, include, consist of, or essentially consist of any suitable components disclosed herein. This disclosure may, additionally or alternatively, be formulated to lack, or substantially contain, any components, materials, ingredients, adjuvants, or species used in prior art compositions or not otherwise necessary for achieving the function and / or purpose of this disclosure.

[0172] All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if any terminology in this application conflicts with or is inconsistent with any terminology in any of the incorporated references, the terminology from this application shall prevail over the conflicting terminology from the incorporated references.

[0173] Unless otherwise indicated herein, all test standards are the most current standards in effect as of the filing date of this application, or, if priority is claimed, the filing date of the earliest priority application in which the test standard appears.

Claims

1. A storage device, Housing and The housing comprises a separator, a cathode, and an anode, wherein the anode and cathode are arranged on both sides of the separator. A storage device in which the cathode and / or anode each comprises a current collector on which an active layer is disposed, and the active layer has a uniform density throughout its entire volume.

2. The storage device according to claim 1, wherein the active layer includes an anode active layer or a cathode active layer, and the cathode active layer or the anode active layer may undergo dimensional and / or geometric changes during the operation of the storage device.

3. The storage device according to claim 1, wherein the current collector can be deformed in accordance with changes in the dimensions or geometric shape of the active layer.

4. The storage device according to claim 2 or 3, wherein the storage device uniformly discharges current during a charge / discharge cycle.

5. The storage device according to claim 4, wherein the discharge of a uniform current during charging or discharging reduces the formation of hot spots in the active layer.

6. The storage device according to claim 5, wherein dendrite formation is reduced compared to a comparative storage device that includes an active layer that does not have a uniform density throughout its entire volume.

7. The storage device according to claim 1, wherein the separator can be deformed to adapt to changes in the dimensions or geometric shape of the active layer.

8. The storage device according to claim 1, wherein the active layer comprises an anode active layer and a cathode active layer, and either the anode active layer or the cathode active layer comprises a first layer and a second layer, the first layer is in contact with the current collector, the second layer is in contact with the first layer, and the second layer has a lower concentration of active material than the first layer.

9. The storage device according to claim 8, wherein the second layer has a higher concentration of carbonaceous material than the first layer.

10. The storage device according to claim 7, wherein the separator comprises a rigid base material, and a flexible material capable of adapting to changes in the shape of the active layer is disposed thereon.

11. The storage device according to claim 7, wherein the separator is in contact with either the active layer or the cathode active layer, and the separator adapts to changes in the shape of the active layer or the cathode active layer.

12. The storage device according to claim 1, further comprising a solid electrolyte containing a polymer, a solvent, and an ionic liquid.

13. It is a method, The housing includes arranging an electrolyte, a separator, an anode, and a cathode, wherein the anode and cathode are arranged on both sides of the separator. A method wherein the cathode and / or anode each comprises a current collector on which an active layer is disposed, and the active layer has a uniform density throughout its entire volume.

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