Using a sheet structure, electrical cell and method

Abstract

According to various embodiments, a sheet structure (10) is used to form a separator (106) of an electrical cell (100a, 100b).

Description

[0001] Various embodiments relate to using a sheet structure, an electrical cell and a method.

[0002] In general, electrical cells, such as accumulators or capacitors, are the focus of research and development, particularly in light of growing efforts toward a sustainable energy economy and the growing interest in mobile electrical devices. To improve the energy density of electrical cells, numerous developments have been presented in recent decades for the deposition of thin films on various substrates. Common substrates include glass, plastics, metals, and, in rare cases, biodegradable materials such as paper or biopolymer films.

[0003] WO 2024 / 054 611 A2 describes a device comprising a decellularized biological scaffold, a first electrode and a second electrode, wherein the decellularized biological scaffold is in electrical and / or chemical connection with the first and second electrodes.

[0004] DE 600 28 409 T2 describes an electrochemical cell with a large anode-cathode interface area and therefore high discharge efficiency. In one embodiment, the cell has a three-dimensional tree-like structure made of a metal, resembling the veins of a leaf, and coated with a separator coating.

[0005] According to various embodiments, it has been recognized that these developments have in common that the substrate is often of little importance for the function of the finished cell and, at most, provides mechanical support. Thus, the substrate contributes to an increase in volume and the cell, which is a hindrance in some applications.

[0006] According to various embodiments, an electric cell and a method as well as a sheet structure for use therein are provided which promote cost-effective production, a compact design and associated high energy density, as well as low internal resistance and associated high efficiency.

[0007] It was clearly recognized that a leaf structure is suitable as a basis for forming a separator, particularly favoring cost-effective production and a more compact cell design. The leaf structure can, for example, provide a carrier that is coated with the cell components. Such a leaf structure is very inexpensive to manufacture compared to conventional concepts, is available worldwide, and, due to its properties, favors the production of a high-performance separator.

[0008] Various examples are described below which relate to what is described herein and shown in the figures.

[0009] Example 1 is using a leaf structure of organic origin to form (e.g., as a component) a separator (e.g., by coating the leaf structure) of an electrical cell, and preferably to form the electrical cell comprising the separator. The leaf structure is a plant leaf skeleton.

[0010] Example 2 is using a sheet structure of organic origin to provide an electric cell having a separator formed by the sheet structure (e.g., by coating the sheet structure).

[0011] Example 3 is an electrical (e.g. electrochemical or capacitive) cell (e.g. the electrical cell from example 1 or 2), comprising: a first electrode (e.g. first electrical potential); a second electrode (e.g. second electrical potential); a separator which is arranged at least in sections between the first electrode and the second electrode (and, for example, spatially separates them from one another); a leaf structure of organic origin, by means of which the separator is formed, wherein the leaf structure is a plant leaf skeleton.

[0012] Example 4 is a method (e.g., for forming the electrical cell according to Example 3), comprising: forming a first electrode (e.g., first electrical potential); forming a second electrode (e.g., second electrical potential); and forming a separator, which is arranged at least partially between the first electrode and the second electrode, wherein a leaf structure of organic origin is used to form the separator, wherein the leaf structure is a plant leaf skeleton.

[0013] Example 5 is the use of a result of the process according to Example 4 as an electrical (e.g. electrochemical or capacitive) cell.

[0014] Example 6 is configured according to any one of Examples 1 to 5, further comprising: coating the first electrode and the second electrode, at least in sections, with a component (e.g., a polymer) of a separator, which is preferably arranged between the first electrode and the second electrode and / or in which the first electrode and the second electrode are preferably embedded. This promotes a compact design.

[0015] Example 7 is configured according to any one of Examples 1 to 6, further comprising: coating the first electrode with a first contact layer (e.g., metal layer); and / or coating the second electrode with a second metal layer. This simplifies electrical contacting.

[0016] Example 8 is configured according to any one of Examples 1 to 7, further comprising: embedding a first edge of the sheet structure (or a base layer formed therefrom) into the first electrode (e.g., by coating the first edge with the first electrode). This promotes a compact design.

[0017] Example 9 is configured according to any one of Examples 1 to 8, further comprising: embedding a second edge of the sheet structure (or a base layer formed therefrom) into the second electrode (e.g., by coating the second edge with the second electrode). This promotes a compact design.

[0018] Example 10 is configured according to any one of Examples 1 to 9, wherein the formation of the first electrode and / or the embedding in the first electrode is carried out by means of liquid-phase deposition, preferably by immersing the sheet structure (or a base layer formed therefrom) in a liquid phase. This simplifies production.

[0019] Example 11 is configured according to any one of Examples 1 to 10, wherein the formation of the second electrode and / or the embedding in the second electrode is carried out by means of liquid-phase deposition, preferably by immersing the sheet structure (or a base layer formed therefrom) in a liquid phase. This simplifies production.

[0020] Example 12 is configured according to any one of Examples 1 to 11, wherein the sheet structure is or will be coated with a component of the separator, preferably by means of liquid-phase deposition and / or on both sides. This promotes a compact design.

[0021] Example 13 is configured according to any one of Examples 1 to 12, wherein the electrical cell further comprises one or more electrodes coated on the sheet structure, preferably on both sides. This promotes a compact design.

[0022] Example 14 is configured according to any one of Examples 1 to 13, wherein the electrical cell further comprises one or more electrodes into which the sheet structure (or a base layer formed therefrom) is embedded. This promotes a compact design.

[0023] Example 15 is configured according to any one of Examples 1 to 14, wherein the sheet structure further provides a base layer, which is, for example, coated with one or more components of the separator and / or which is, for example, coated to form the separator, e.g., to form the electrical cell. This promotes a compact design.

[0024] Example 16 is configured according to any one of Examples 1 to 15, wherein the electrical cell further comprises one or more electrodes into which the leaf structure extends, preferably in which the leaf structure is embedded. This promotes a compact design.

[0025] Example 17 is configured according to any one of Examples 1 to 16, wherein the electrical cell further comprises one or more electrodes extending into a portion of the separator, preferably embedded in the separator. This facilitates a compact design.

[0026] Example 18 is configured according to any one of Examples 1 to 17, wherein the electrical cell further comprises one or more electrodes coated with a portion of the separator, preferably on both sides. This facilitates a compact design.

[0027] Example 19 is configured according to any one of Examples 1 to 18, further wherein the leaf structure is flexible and / or of plant origin. This simplifies production.

[0028] Example 20 is configured according to any one of Examples 1 to 19, further wherein the sheet structure and / or the separator (or at least the base layer) comprises a polymer, preferably cellulose, more preferably ethylcellulose. This simplifies manufacturing.

[0029] Example 21 is configured according to Example 20, wherein the polymers are or become crosslinked, preferably by irradiating the polymer, more preferably with electromagnetic radiation (e.g., UV), and / or by heating the polymer. This simplifies production.

[0030] Example 22 is configured according to Example 21, further comprising calibrating a process (e.g., irradiation and / or heating) by means of which the polymer is crosslinked, for example, based on at least one parameter representing a gas permeability (e.g., its desired state and / or actual state) of the separator. This simplifies production.

[0031] Example 23 is configured according to any one of Examples 1 to 22, further comprising the sheet structure and / or the separator (or at least the base layer) being gas-permeable. This simplifies manufacturing.

[0032] Example 24 is configured according to any one of Examples 1 to 23, further wherein the leaf structure has a three-dimensional structure, preferably wherein the three-dimensional structure has a fractal-based design. This simplifies manufacturing.

[0033] Example 25 is configured according to any one of Examples 1 to 24, further wherein the leaf structure (or a base layer formed therefrom) is porous and / or has a plurality of filaments, preferably in the form of leaf veins and / or branching from one another. This simplifies manufacturing. A porous base layer facilitates, for example, the manufacture of a porous and / or gas-permeable separator.

[0034] Example 26 is configured according to any one of Examples 1 to 25, further wherein the separator is ionically conductive and / or porous; and / or wherein the separator comprises a dielectric material (e.g., a porous matrix thereof). This increases the energy density and / or the efficiency.

[0035] Example 27 is configured according to any one of Examples 1 to 26, wherein the cell is configured as an energy storage device.

[0036] Example 28 is configured according to any one of Examples 1 to 27, wherein the base layer and / or the separator comprise a plurality of channels, e.g., in the form of a network of interconnected channels, e.g., are penetrated by them (e.g., so that they are fluid-permeable, e.g., gas-permeable). This facilitates the uptake of an electrolyte by means of the separator.

[0037] Example 29 is configured according to any one of Examples 1 to 28, wherein a (e.g., ion-conductive) membrane is formed using the sheet structure. This simplifies fabrication.

[0038] Example 30 is configured according to any one of Examples 1 to 29, wherein the separator comprises one or more halogen complexing agents coated, for example, on the sheet structure (or a base layer formed therefrom). This helps limit gas accumulation and produce stable cell performance.

[0039] Example 31 is configured according to any one of Examples 1 to 30, wherein the cell has a base layer having the sheet structure. This simplifies manufacturing.

[0040] Example 32 is configured according to any one of Examples 1 to 31, wherein the cell comprises a first electrode into which a first edge of the sheet structure (or a base layer formed therefrom), e.g., filaments thereof, is embedded.

[0041] Example 33 is configured according to any one of Examples 1 to 32, wherein the cell comprises a second electrode (e.g., second electrode) into which a second edge of the sheet structure (or a base layer formed therefrom), e.g., filaments thereof, opposite the first edge is embedded.

[0042] Example 34 is configured according to any one of Examples 1 to 33, wherein the first electrode (e.g., electrode of first electrochemical potential) and / or the second electrode (e.g., second electrode) are coated at least in sections with a component of the separator.

[0043] Example 35 is configured according to any one of Examples 1 to 34, wherein the cell is configured as a capacitive cell or as an electrochemical cell.

[0044] Example 36 is configured according to any one of Examples 1 to 35, wherein, when the cell is configured as an electrochemical cell, the first electrode and the second electrode differ from each other in their electrochemical potential and / or in a material (e.g., metal) that they comprise or consist of, or the first electrode and the second electrode comprise or consist of carbon (e.g., in a carbon modification such as graphite).

[0045] Example 37 is configured according to any one of Examples 1 to 36, wherein, when the cell is configured as a capacitive cell, the first electrode and the second electrode match in their electrochemical potential and / or in a metallic material (e.g., metal) that they comprise or consist of.

[0046] Example 38 is configured according to any one of Examples 1 to 37, wherein the electrochemical cell is configured as a redox flow battery, e.g., a vanadium redox battery, a polysulfide bromide battery, a sodium chloride redox battery, a zinc bromine battery, or a uranium redox battery. This provides a high-performance cell.

[0047] Example 39 is configured according to Example 38, wherein the redox flow accumulator is an organic redox flow accumulator and / or wherein the redox flow accumulator is quinone (e.g., quinone) and / or hydroquinone (e.g., hydroquinone) based.

[0048] Example 40 is configured according to any one of Examples 1 to 39, wherein the leaf structure is or is provided based on a plant leaf, preferably by removing plant tissue from the plant leaf. This simplifies manufacturing.

[0049] Example 41 is configured according to any one of Examples 1 to 40, wherein the sheet structure (or at least a base layer formed therefrom), e.g., filaments thereof, is embedded at least in sections in the separator (or a section thereof), preferably arranged between two sections of the separator. This simplifies production.

[0050] Example 42 is configured according to any one of Examples 1 to 41, wherein (e.g., when the cell is configured as an electrochemical cell), the cell further comprises: a first contact layer (e.g., metal layer) coated on the first electrode; and / or a second contact layer (e.g., metal layer) coated on the second electrode. This facilitates electrical contacting.

[0051] Example 43 is configured according to any one of Examples 1 to 42, wherein the sheet structure (or at least a base layer formed therefrom) is at least partially coated on both sides with the first electrode and / or protrudes into it; and / or wherein the sheet structure (or at least a base layer formed therefrom) is at least partially coated on both sides with the second electrode and / or protrudes into it. This increases the energy density and / or the efficiency.

[0052] Example 44 is configured according to any one of Examples 1 to 43, wherein the first electrode is coated at least partially on both sides with a component of the separator; and / or wherein the second electrode is coated at least partially on both sides with a component of the separator. This increases the energy density and / or the efficiency.

[0053] Example 45 is configured according to any one of Examples 1 to 44, wherein the first electrode protrudes at least partially from the separator (e.g., on a side of the electrode opposite the second edge); and / or wherein the second electrode protrudes at least partially from the separator (e.g., on a side of the electrode opposite the first edge). This facilitates electrical contacting.

[0054] Example 46 is configured according to any one of Examples 1 to 45, wherein the first electrode is at least partially embedded in the separator; and / or wherein the second electrode is at least partially embedded in the separator. This increases the energy density and / or the efficiency.

[0055] Example 47 is configured according to any one of Examples 1 to 46, wherein the first electrode is disposed at least partially between a portion of the separator and the base layer; and / or wherein the second electrode is disposed at least partially between a portion of the separator and the base layer. This increases the energy density and / or the efficiency.

[0056] Example 48 is configured according to any one of Examples 1 to 47, wherein a portion of the separator, preferably in contact with the base layer, is disposed between the first electrode (e.g., electrode of first electrochemical potential) and the second electrode (e.g., second electrode). This increases the energy density and / or the efficiency.

[0057] Example 49 is configured according to any one of Examples 1 to 48, wherein the separator spatially separates the first electrode and the second electrode from each other and / or couples them to each other in an ion-conductive manner.

[0058] Example 50 is configured according to any one of Examples 1 to 49, further comprising: an electrolyte accommodated by the separator (e.g., one or more cavities thereof).

[0059] Example 51 is configured according to any one of Examples 1 to 50, wherein the separator is or will be formed by means of the sheet structure.

[0060] Example 52 is configured according to any one of Examples 1 to 51, wherein the leaf structure is (or will be) arranged at least in sections between the first electrode and the second electrode and / or is (or will be) integrated at least in sections into the separator.

[0061] Example 53 is configured according to any one of Examples 1 to 52, wherein the sheet structure is preferably a component of the separator and / or coated with one or more than one component (e.g., a polymer and / or a halogen complexing agent) of the separator (or at least one component thereof).

[0062] Example 54 is configured according to any one of Examples 1 to 53, wherein the first electrode is formed on (e.g., above) the leaf structure and / or coupled to the leaf structure; wherein the second electrode is formed on (e.g., below) the leaf structure and / or coupled to the leaf structure.

[0063] Example 55 is configured according to any one of Examples 1 to 54, wherein the sheet structure is used to form the separator and / or a base layer.

[0064] Example 56 is configured according to any one of Examples 1 to 55, wherein the base layer comprises one or more polymer layers and the sheet structure coated therewith and / or wherein the base layer provides a component of the separator.

[0065] Example 57 is configured according to any one of Examples 1 to 56, wherein the leaf structure is integrated into the separator or at least coated with the component of the separator.

[0066] Example 58 is configured according to any one of Examples 1 to 57, wherein the separator of the cell is arranged at least in sections between the first electrode of the cell and the second electrode of the cell.

[0067] Example 59 is configured according to any one of Examples 1 to 58, wherein forming the separator comprises coating the sheet structure with one or more additional sheet structures, with one or more polymers, for example with cellulose (e.g., ethylcellulose) and / or with chitosan.

[0068] Example 60 is configured according to any one of Examples 1 to 59, which is further configured according to any one of the appended claims.

[0069] It shows Fig. 1A and B each show a cell according to various embodiments in a schematic side view or cross-sectional view; Fig. 2 a cell according to various embodiments in a schematic side view or cross-sectional view; Fig. 3 shows a method according to various embodiments in a schematic flow diagram; Fig. 4 Top views of a plant leaf during and after providing the leaf structure (or a base layer formed therefrom), according to various embodiments; Fig. 5 shows the discharge curve of an exemplary electrochemical cell according to various embodiments in a schematic diagram; Fig. 6A and B show details of this discharge curve in different schematic diagrams; Fig. 7 shows the discharge curve of an exemplary capacitor according to various embodiments in a schematic diagram; Fig. 8A and B each show a cell according to various embodiments in a schematic side view or cross-sectional view; and Fig. 9A to C each show implementations of the separator according to various embodiments in a schematic cross-sectional view.

[0070] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology such as "top", "bottom", "front", "back", "fore", "rear", etc., will be used with reference to the orientation of the described figure(s). Since components of embodiments can be positioned in a number of different orientations, the directional terminology is for the purpose of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention.It is understood that the features of the various exemplary embodiments described herein may be combined with one another unless specifically stated otherwise. The following detailed description is therefore not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims.

[0071] In this description, the terms "connected," "attached," and "coupled" are used to describe both a direct and an indirect connection (e.g., resistive and / or electrically conductive, e.g., an electrically conductive connection), a direct or indirect connection, and a direct or indirect coupling. In the figures, identical or similar elements are provided with identical reference numerals where appropriate.

[0072] In this description, reference is made to the term "plant leaf" (also referred to as leaf for short) and components thereof, such as its leaf veins, its plant tissue, or the like, which are objects of organic (more precisely: plant) origin. The leaf veins form a coherent and multiply branched structure that can be exposed by removing the plant tissue (e.g., the biomass). The structure of leaf veins forms the so-called leaf structure, e.g., a leaf skeleton (also referred to as leaf scaffold), which comprises or consists of, for example, cellulose, lignin, and / or hemicellulose.

[0073] In the context of this description, the term "biodegradable" with regard to an object is understood to mean that it is an object which consists of components and / or materials, for example from renewable raw materials, the majority of which, for example more than 80%, for example more than 90% of which, can dissolve or decompose into its elementary components such as carbon, oxygen, hydrogen, carbon dioxide, humic acids, etc. and / or other minerals under the influence of external factors (enzymes, (micro)organisms, electromagnetic radiation (e.g. UV and light radiation), pressure, solvents (e.g. water), etc.) within a certain period of time (e.g. a period which is longer than the usual periods of the manufacturing process of the object and / or the (e.g. organic) electronic components, for example 10, 20, 50 times longer).Examples of such components which have the electrical cell or are at least coupled to it include: thin-film electronic components, such as organic electronic components, or oxide thin-film transistors (e.g. ZnO etc.).

[0074] Cellulose and its derivatives, such as ethylcellulose, are biomolecules and polysaccharides consisting solely of organic compounds. Cellulose is the main component of plant cell walls. Therefore, it is understood that cellulose and its derivatives are biodegradable. Cellulose and its derivatives also have the advantage of being non-toxic, dielectric, and inexpensive.

[0075] The term "flexible" with regard to an object is used in this description to mean that the object is elastically (e.g. damage-free and / or reversibly) deformable (e.g. bendable), e.g. up to a deflection of at least 10% (e.g. at least 25%) based on the extension of the object along which the bending line runs.

[0076] An electrical cell (also simply referred to as a cell) is a device by means of which electrical energy can be absorbed, released, or stored in the form of other (e.g., chemical or potential) energy. An electrical cell has two half-cells (also referred to as electrodes) that are coupled to one another (e.g., by means of an electrolyte and / or a separator). The electrical cell can be configured as a capacitive or electrochemical cell, as described in more detail below.

[0077] An electrochemical cell is an electrical cell by means of which chemical energy and electrical energy can be converted into one another and, for example, the chemical energy can be stored. If chemical energy is converted into electrical energy by means of the electrochemical cell, which can be taken from the electrochemical cell, the cell is of the galvanic cell type (also known as a battery). If the electrochemical cell absorbs electrical energy and converts it into chemical energy, it is of the electrolytic cell type. An electrochemical cell of the accumulator type can be operated either as an electrolytic cell or as a battery. The chemical energy generated during operation as an electrolytic cell can be stored in the accumulator and converted back into electrical energy during operation as a battery.

[0078] The electrodes of the electrochemical cell (simply referred to as electrochemical electrodes) are coupled to one another (e.g. by means of an electrolyte and / or a separator) in such a way that they can exchange electrical charge with one another (e.g. in the form of ions). During operation of the electrochemical cell, oxidation takes place at the electrode operated as the anode (simply referred to as the electrochemical anode) and the corresponding reduction takes place at the electrode operated as the cathode (simply referred to as the electrochemical cathode). The electrodes interact with one another by means of the exchange of electrical charge (also referred to as charge exchange). The separator of an electrochemical cell clearly provides an ion-conductive membrane by means of which the charge exchange (e.g. ion exchange) between reduction and oxidation takes place.

[0079] Examples of an electrochemical anode include or consist of one or more of the following materials: zinc (oxidation potential is approximately -0.76 V relative to a standard hydrogen electrode), carbon (e.g., in a carbon modification such as graphite). The oxidation potential of graphite can be approximately -0.86 V relative to a standard hydrogen electrode.

[0080] Examples of an electrochemical cathode comprise or consist of one or more than one of the following materials: lithium or at least one chemical compound (e.g., an oxide) comprising lithium, such as lithium cobalt oxide (e.g., LiCoO2), whose oxidation potential may be in a range of about +4.3 V to about -3.8 V versus Li0 / Li+, lithium manganese oxide (e.g., LiMn2O4), whose oxidation potential may be in a range of about +4.3 V to about -3.8 V versus Li0 / Li+; and / or an oxide, such as manganese dioxide (e.g., MnO2), whose oxidation potential may be about +0.250 V versus standard hydrogen electrode.

[0081] The two electrochemical electrodes differ in their electrochemical potential, so that an electrical potential is generated between them. The respective electrochemical potential of an electrochemical electrode is a function of the electrode's chemical composition and can be compared, for example, with an electrode of a different electrochemical potential using the electrochemical series, which is a list of redox pairs according to their standard electrode potential (redox potential under standard conditions versus the standard hydrogen electrode).

[0082] The two electrodes of the electrochemical cell are separated from one another (e.g. spatially and / or electrically) by means of the (e.g. electrically insulating) separator, whereby the separator is optionally permeable to ions. For example, the separator can have a lower conductivity for electrons than for ions. Alternatively or additionally, the separator can be gas-permeable and / or contain the electrolyte, which is accommodated, for example, in cavities (e.g. channels) of the separator. For example, the separator can be porous and / or contain filaments, e.g. a composite of filaments (e.g. in the form of a sheet structure, a woven fabric, a knitted fabric, a braid, a net, a fleece or the like) and / or a network of interconnected cavities (e.g. channels).

[0083] A capacitive cell (also called a capacitor) is a device by means of which electrical energy and the potential energy of an electric field can be converted into one another, whereby the associated electrical charge is statically stored and generates the electric field. When electrical energy is absorbed by the capacitive cell, it is converted into the potential energy of the electric field that is formed between the electrodes (also called capacitor electrodes). One of the capacitor electrodes acts as the anode and the other of the two capacitor electrodes as the cathode (also called capacitor anode and capacitor cathode). The capacitor electrodes can be metallic (e.g., they can match in terms of the metal they comprise or are made of) and / or have the same electrochemical potential.Examples of a capacitor electrode include or consist of one or more of the following materials: carbon black, graphite, aluminum, and / or aluminum oxide.

[0084] The term "ionically conductive" refers to a conductivity for ions (e.g., in a solid, liquid, and / or gas), e.g., through the movement of cations and / or anions. The resulting electrical conductivity can be greater than 10 -10 S / cm (Siemens per centimeter), e.g. in a range of approximately 10 -10 S / cm to approximately 10 -1 S / cm (e.g. 10 -4 S / cm) and / or greater than 10 -9 S / cm, e.g. greater than 10 -7 S / cm, e.g. greater than 10 -5 S / cm.

[0085] The term "permeable" refers to the permeability (also referred to as permeability) of a fluid, e.g., a gas (also referred to as gas permeable) and / or a liquid (also referred to as liquid permeable). For example, permeation occurs when a material (the so-called permeate) penetrates a solid. Permeability is expressed in GTR (gas transmission rate), which corresponds to one mole per square meter, second, and Pascal (e.g., under standard conditions), and can optionally be normalized to the length along which the permeability is specified. Permeability can, for example, be greater than 0.1 cm 3 / m 2 Day, e.g. as 10 cm 3 / m 2 day, e.g. as 1000 cm 3 / m 2 Day.

[0086] An electrolyte can refer to a substance or a mixture of substances which can conduct ions, i.e. is ionically conductive. The electrolyte can comprise or be formed from solid or liquid components. For example, the electrolyte can comprise or be formed from one or more of the following components: a liquid electrolyte (e.g. conductive salt with solvent and optional additives), a polymer electrolyte, an electrolyte based on an ionic liquid, and / or a solid electrolyte. Optionally, the electrolyte can comprise a mixture of different components, e.g. a mixture thereof. Alternatively or additionally, several electrolyte types and / or components can be used alongside one another within a cell.

[0087] The base layer can, for example, provide a support (e.g., a substrate) for the components of the cell (also referred to as cell components), or at least be coated with the components of the cell. In some embodiments, the base layer provides part of the separator of the cell (e.g., by being integrated into the separator and / or by containing the electrolyte) or is at least coated with layers of the separator. An exemplary implementation of the base layer comprises or consists of (e.g., dielectric and / or organic) filaments (e.g., a coherent composite of filaments). For example, the base layer can be porous and / or comprise filaments (e.g., sheets), e.g., a composite of filaments (e.g., in the form of a sheet structure, a woven fabric, a knitted fabric, a braid, a net, a fleece, or the like) and / or a network of interconnected cavities (e.g., channels).

[0088] With regard to the filaments of the base layer, particular reference is made herein to filaments in the form of leaf veins, for example, when the base layer has or consists of a leaf structure. Leaf veins offer inexpensive and ecological production, are mechanically very robust, and are biodegradable. In this regard, however, it is understood that the base layer can optionally comprise any other suitable type of (e.g., dielectric) filaments, for example, filaments comprising ceramic (e.g., glass), plastic, and / or carbon in a carbon modification.

[0089] Examples of filaments include: leaf veins, fibers (e.g., textile fibers, glass fibers, thermoplastic fibers, or carbon fibers), hairs, threads, wires, and the like. Examples of the base layer include: a leaf skeleton (e.g., coated with ethylcellulose); a carbon fiber mat, a glass fiber mat, a glass fiber fleece, a textile, a grid (e.g., made of thermoplastic), a (e.g., perforated) film, a foam layer.

[0090] For ease of understanding, reference is made herein to a base layer, which may comprise or consist of one or more leaf structures. For example, the base layer may be provided by means of one or more leaf structures, as described in more detail below. It should be understood, at least with regard to geometric details (orientation, shape, etc.), that what is described for the base layer may apply analogously to the leaf structure, and vice versa.

[0091] Forming the base layer may, for example, comprise coating one or more than one sheet structure (e.g., a plurality of stacked sheet structures), for example with cellulose, preferably with ethylcellulose, and / or with a halogen complexing agent. Forming the base layer may, for example, comprise connecting (e.g., laminating) a plurality of sheet structures arranged one above the other (also referred to as stacked sheet structures) to one another, for example by means of cellulose, preferably with ethylcellulose. Advantageous exemplary properties of the base layer include: plate-shaped (or at least ribbon-shaped), porous, comprising filaments, penetrated by cavities (e.g., channels), dielectric, organic (or comprising at least one polymer).

[0092] Reference is further made herein to various types of cell architectures, including the so-called lateral architecture and the so-called vertical architecture, which differ from one another in the orientation of the sheet structure (or a base layer formed therefrom) with respect to the electrodes. In this regard, it can be understood that what has been described for the lateral architecture can apply analogously to the vertical architecture and vice versa. The sheet structure (or a base layer formed therefrom) can, for example, be elongated from the first edge to the second edge along a reference direction. The sheet structure (or a base layer formed therefrom) can have a thickness transverse to the reference direction (e.g., along a direction perpendicular thereto, which is also referred to as the thickness direction) and / or be penetrated by a plurality of channels.If the cell is of the lateral architecture type, the reference direction runs from the first electrode to the second electrode and / or the thickness direction runs between the first electrode and the second electrode. If the cell is of the vertical architecture type, the reference direction runs between the first electrode and the second electrode and / or the thickness direction runs from the first electrode to the second electrode. These different types of cell architecture will first be explained using . Fig. 8A and B are explained.

[0093] Fig. 8A illustrates a lateral architecture type cell 800a according to various embodiments in a schematic side view or cross-sectional view and Fig. 8B shows a cell of the vertical architecture type 800b according to various embodiments in a schematic side view or cross-sectional view, wherein the reference direction 101 is transverse to the thickness direction 105.

[0094] According to various embodiments, the separator 106 may include one or more than one sheet structure 10. For example, the separator 106 may include or consist of a base layer 102 including or consisting of the sheet structure 10. The sheet structure 10 (or the base layer 102) may be configured, for example, according to Example 26.

[0095] The sheet structure 10 (or a base layer 102 comprising or consisting thereof) may have two opposing edges (also referred to as first edge 102l and second edge 102r) with respect to the reference direction 101. The sheet structure 10 (e.g., a base layer 102 comprising or consisting thereof) may, for example, be longitudinally extended from the first edge 102l to the second edge 102r along the reference direction 101 and may have a thickness 102d transversely to the reference direction 101 (e.g., along a direction 105 perpendicular thereto) and / or be penetrated by a plurality of channels.

[0096] Illustratively speaking, in the case of the lateral architecture 800a, the electrodes 104l, 104r are spaced apart from one another along the reference direction 101. Optionally, the first edge 102l can be arranged in the first electrode 104l and the second edge 102r can be arranged in the second electrode 104r (e.g., embedded therein). Alternatively or additionally, the electrodes 104l, 104r are arranged at least laterally (also referred to as lateral).

[0097] Illustratively speaking, in the case of the vertical architecture 800b, the electrodes 104l, 104r are spaced apart from one another along the thickness direction 105. For example, an upper side of the sheet structure 10 (or a base layer comprising it or consisting thereof) can face the first electrode 104l (e.g., adjoin it), and an underside of the sheet structure 10 (or a base layer comprising it or consisting thereof) can face the second electrode 104r (e.g., adjoin it). Alternatively or additionally, in the case of the vertical architecture 800b, the electrodes 104l, 104r are arranged, for example, above and below the sheet structure 10.

[0098] In the case of an electrochemical cell, the two electrodes 104l, 104r may differ from each other in their electrochemical potential. For example, the first electrochemical electrode 104l may have a first electrochemical potential (then also referred to as the first electrochemical potential electrode). The second electrochemical electrode 104r may, for example, have a second electrochemical potential (then also referred to as the second electrochemical potential electrode). For example, one of the two electrochemical electrodes 104l, 104r may provide an electrochemical anode and the other of the two electrodes 104l, 104r may provide an electrochemical cathode.

[0099] In the case of a capacitive cell, the two capacitor electrodes 104l, 104r may match in their electrochemical potential and / or chemical composition. Optionally, one or more of the capacitor electrodes 104l, 104r may be passivated, e.g., by means of a dielectric layer, and / or galvanically separated from each other (e.g., by means of separator 106). The smaller the distance between the capacitor electrodes 104l, 104r, the greater the capacitance of the capacitive cell.

[0100] In a less complex implementation, the separator may consist of the base layer 102. In other implementations, the base layer 102 may be integrated (or at least embedded) into the separator, for example, by coating the base layer 102 with one or more components of the separator 106.

[0101] For example, the separator 106 (or at least the base layer 102) may have a greater conductivity for ions than for electrons and / or may comprise a dielectric material (e.g., a porous matrix thereof). For example, the conductivity for ions may be 10 k -times the conductivity for electrons, where k is equal to 3 or greater, e.g., 4 or greater, e.g., 5 or greater, e.g., 6 or greater. Alternatively or additionally, a porosity of the separator 106 (or at least of the base layer 102) can be in a range from approximately 10 nm to approximately 100 µm (relative to the radius of the pores). The radius of a pore can be understood, for example, as the radius of a sphere having the volume of the pore.

[0102] Examples of the (e.g., dielectric) material include: an organic material (e.g., polymer), e.g., cellulose (e.g., ethylcellulose); an oxide (e.g., glass); a ceramic. Reference is made herein, inter alia, to ethylcellulose as a dielectric material, although it should be understood that what is described herein may also apply to any other dielectric material.

[0103] The thickness 102d of the base layer 102 can, for example, be in a range from approximately 1 µm to approximately 100 µm. The porosity of the base layer 102 can, for example, be in a range from approximately 10 nm to approximately 100 µm. The thickness of filaments of the base layer 102 can, for example, be in a range from approximately 10 nm (nanometers) to approximately 100 µm (micrometers).

[0104] The distance of the first edge 102l from the second edge 102r may be greater than the 10 ktimes the thickness 102d of the base layer 102, where k is equal to 3 or greater, e.g. 4 or greater, e.g. 5 or greater, e.g. 6 or greater. Exemplary implementation of the lateral architecture 800a

[0105] The base layer 102 may have two opposing edges (also referred to as first edge 102l and second edge 102r) with respect to the reference direction 101, each edge of which is embedded in one of the two electrodes 104l, 104r (also referred to as first electrode 104l and second electrode 104r) that are spaced apart from one another. For example, a portion of the base layer 102 (e.g., along the reference direction 101) that is embedded in the two electrodes 104l, 104r may be greater than approximately 10%, e.g., than approximately 25%, e.g., than approximately 50%, e.g., than approximately 75%, e.g., than approximately 90%. Alternatively or additionally, a distance between the two electrodes may be smaller than approximately 75% (e.g., than approximately 50%, e.g., than approximately 25%, e.g., than approximately 10%) of the extent of the base layer 102 along the reference direction 101. Exemplary implementation of the 800b vertical architecture

[0106] The base layer 102 may have two opposing sides (also referred to as top and bottom) which are spaced apart along the thickness direction 105, and each side of which is coated with one of the two electrodes 104l, 104r (also referred to as first electrode 104l and second electrode 104r), which, for example, are spaced apart. For example, a proportion of the base layer 102 (e.g., along the reference direction 101) which is coated with the two electrodes 104l, 104r may be greater than approximately 10%, e.g., approximately 25%, e.g., approximately 50%, e.g., approximately 75%, e.g., approximately 90%, e.g., approximately 99%. Alternatively or additionally, the distance between the two electrodes may be less than approximately 10 -k the extent of the base layer 102 along the reference direction 101, where k is equal to 3 or greater, e.g. 4 or greater, e.g. 5 or greater, e.g. 6 or greater.

[0107] With regard to the nature of the components of the cell, reference is made below to the lateral architecture 800a, whereby what is described therein can apply analogously to the vertical architecture 800b.

[0108] Fig. 1A illustrates a cell according to various embodiments 100a (e.g., according to Example 1, e.g., Example 27) in a schematic side view or cross-sectional view, which may be configured, for example, as a capacitive cell or as an electrochemical cell.

[0109] As illustrated, the separator 106 may include at least one (i.e., one or more than one) layer (also referred to as a separator layer), each separator layer extending contiguously from the first electrode 104l to the second electrode 104r and / or including a portion 106m (as a component of the separator 106) disposed between the first electrode 104l and the second electrode 104r. The portion 106m may, for example, contact the first electrode 104l, the second electrode 104r, and / or the base layer 102. Alternatively or additionally, the first electrode 104l, the second electrode 104r, and / or the base layer 102 may be coated with a component of the separator 106.

[0110] If the separator 106, as shown by way of example, has two layers between which the base layer 102 is arranged, the first electrode 104l and / or the second electrode 104r can extend at least partially into the separator 106 (e.g., embedded therein). Alternatively or additionally, the separator 106 can touch three sides of the first electrode 104l and / or the second electrode 104r.

[0111] For example, a proportion of the first electrode 104l and / or the second electrode 104r (e.g., along the reference direction 101) which is embedded in the separator 106 may be greater than approximately 10%, e.g., than approximately 25%, e.g., than approximately 50%, e.g., than approximately 75%, than approximately 90%.

[0112] In some embodiments, the first electrode 104l and / or the second electrode 104r may have a portion (also referred to as a contact portion) that protrudes from the separator 106. This facilitates coating the contact portion 104k with a (e.g., metallic) contact, as will be described in more detail later.

[0113] Several of the cells provided herein are particularly suitable for being connected in series or parallel to one another (e.g. by stacking), which is generally difficult with conventional thin-film components (e.g. batteries).

[0114] Fig. 1B illustrates an electrochemical cell 100b according to various embodiments (e.g., according to Example 7 and / or 42) in a schematic side view or cross-sectional view, in which each of the electrochemical electrodes 104l, 104r (e.g., their contact portion 104k) is coated with a contact layer 108 (e.g., comprising one or more metal layers). For example, the metal layer 108 may comprise or consist of at least copper and / or silver. A non-metallic contact layer 108 may, for example, comprise or consist of carbon in a carbon modification (e.g., graphite).

[0115] Fig. 2 illustrates an electrochemical cell according to various embodiments 200 (e.g., according to Example 43) in a schematic side view or cross-sectional view, wherein the first electrode 104l exemplarily comprises or consists of manganese oxide and the second electrode 104r exemplarily comprises zinc and / or zinc oxide. The base layer 102 has a leaf skeleton, which is or will be coated on both sides with the first electrode 104l, the second electrode 104l, and components of the separator 106. The separator 106 can, for example, comprise or consist of ethylcellulose, which promotes particularly cost-effective production and is biodegradable.

[0116] Fig. 3 illustrates a method 300 according to various embodiments (e.g., according to Example 4) in a schematic flow diagram. With regard to coating (e.g., one side), reference is made by way of example to so-called wet coating (also referred to as liquid phase deposition), in which coating is carried out using a liquid phase (also referred to as coating liquid) with which the object to be coated is coated. The layer of coating liquid on the object to be coated can subsequently be converted into a solid state, e.g., by means of drying and / or polymerization. With regard to wet coating, it can be understood that what has been described for this purpose can apply analogously to any other type of coating, for example, dry coating (e.g., vapor deposition), such as, for example, chemical and / or physical vapor deposition, powder coating, and the like.

[0117] An exemplary implementation of the coating liquid comprises a solution whose chemical composition corresponds to the chemical composition of the layer to be produced from it. Alternatively or additionally, the coating liquid can comprise or consist of a highly viscous screen printing ink.

[0118] With regard to wet coating, reference is made, among other things, to so-called dip coating, in which the object to be coated is immersed in the coating liquid. Dip coating is particularly cost-effective and simplifies the embedding of the object to be coated. With regard to dip coating, it should be understood that what is described here can apply analogously to any other suitable method of wet coating, e.g., by spraying, printing, and the like.

[0119] The formation 301 of the first electrode can be carried out, for example, by coating (e.g., the first edge) of a base layer with the first electrode. The formation 303 of the second electrode can be carried out, for example, by coating (e.g., the second edge) of the base layer with the second electrode. Alternatively or additionally, this can be carried out by means of a coating liquid into which the base layer is, for example, immersed (also referred to as dip coating). The coating liquid has a chemical composition that corresponds to the chemical composition of the electrode to be produced.

[0120] The formation 305 of the separator can be carried out, for example, by coating the first electrode and / or second electrode with one or more than one component of the separator. Alternatively or additionally, this can be carried out by means of a coating liquid, for example by means of a polymer solution as the coating liquid and / or by printing the coating liquid. For example, the formation 305 of the separator can comprise immersing the sheet structure (e.g., the base layer formed therefrom) in the coating liquid. The immersion can be carried out, for example, for a specific period of time from 3 minutes to 24 hours, and / or, for example, at a temperature in a range from 20°C to 100°C, for example 25°C to 90°C.

[0121] In an exemplary implementation of wet coating (e.g., with an electrode and / or with the separator), a mask can be used that is configured to shield a portion of the object to be coated from the coating liquid. Alternatively or additionally, the desired geometry of the coating can be printed. This facilitates, for example, the protrusion of the first electrode 104r and / or the second electrode 104l from the separator.

[0122] It should be noted that the lateral cell architecture and the corresponding manufacturing process allow the electrode(s) to be coated with the separator (or at least a portion thereof) on multiple (e.g., three) sides. Compared to vertical architectures, where the separator is coated with an electrode, for example, this provides a larger contact area between the cell components, which reduces the electrochemical energy density and potentially the internal resistance, thus increasing the cell's performance.

[0123] This addresses the fact that the electrochemical reactions that generate the electrical current primarily occur on the surface of the electrode(s). In this regard, various embodiments have recognized that, in conventional cells, the reactivity available in the volume of the electrodes is not fully utilized. The cell provided herein better utilizes this reactivity because a large portion of the electrode volume is available for electrochemical reactions, which leads to a higher current density for the same amount of material and is advantageous, for example, in thin-film batteries. For this purpose, the freestanding base layer (which can, for example, provide a battery separator layer) can be provided with dip-coated electrodes (based on high-viscosity screen printing inks) on both sides.

[0124] Optionally, the method 300 comprises, in 307, forming one or more contact layers (e.g., metal layers), for example, on an electrochemical electrode. For this purpose, the first electrochemical electrode and / or the second electrochemical electrode can be coated with a respective contact layer.

[0125] Optionally, the method 300 comprises, in 309, providing the base layer, for example based on a plant leaf, as described in more detail below.

[0126] In an exemplary implementation, the base layer (e.g., providing a membrane) is manufactured using one or more than one leaf skeleton. The leaf skeleton may comprise the leaf veins (also called leaf ribs) that remain when the green cells (called mesophyll) are removed from the plant leaf. This quasi-fractal structure of a leaf skeleton can be used as a natural, layer-supporting scaffold (illustratively as a layer formation nucleus) that can be coated (e.g., impregnated) with one or more than one functional material (such as a biodegradable, solution-fabricated polyvinyl alcohol (PVA) sponge). The resulting biopolymer structure can provide an ion-conducting separator (e.g., comprising or consisting of one or more than one separator layer) for the cell (e.g., configured as a redox flow battery). Example of an implementation of the procedure:

[0127] The separator can be produced using an ink containing a PVA solution with cellulose fibers and an ionic liquid (e.g., [EMIM][ESO4] (1-ethyl-3-methylimidazolium ethyl sulfate) and a polyacrylic acid solution in water). This ink (also referred to as a solution in this context) is poured into a Petri dish, and the leaf scaffolds are immersed in it. Acetone is poured over it until the ink and the submerged leaf scaffolds are immersed in an acetone bath. The Petri dish is exposed to UV irradiation for 3 minutes to mechanically stabilize the pores through cross-linking, while the acetone evaporates. The Petri dish is then placed on a hot plate at 60 °C for complete drying. The coated leaf scaffolds are cut out and are ready for use as ion-conducting, biodegradable, porous separators, for example, by adding a suitable electrolyte. Example of electrode production:

[0128] Silver ink is printed onto two sheet structures (or glass substrates) to form a current collector. The active electrode material, based, for example, on a graphite ink, is printed onto this. In a battery, for example, both electrodes may be made of graphite. In a Zn-ion hybrid supercapacitor (ZHSC), the anode is made of Zn (zinc) and the cathode is made of graphite. In a Zn-Br cell, the anode is made of Zn and the cathode is made of graphite. Finally, the separator is immersed in a 10-15M (water in salt) solution of a suitable electrolyte before being placed between the selected electrodes.

[0129] Fig. 4A-C illustrate top views of a plant leaf during and after providing the leaf structure (or a base layer formed therefrom), according to various embodiments 400.

[0130] According to various embodiments, providing a leaf structure (or a base layer formed therefrom) may comprise: providing a plant leaf 20, wherein the plant leaf 20 has a plurality of leaf veins 30 and plant tissue (e.g., biomass) arranged between and / or around the leaf veins 30; treating the plant leaf such that the plant tissue is removed from the plant leaf; and optionally drying the treated plant leaf to form the leaf structure 10.

[0131] For example, the leaf structure can be produced from a plant leaf that may have been degreened. For example, the leaf structure 10 may essentially contain only the leaf veins of the plant leaf (e.g., without plant tissue). According to various embodiments, the leaf veins can, for example, essentially retain their three-dimensional, for example, network-like and / or quasi-fractal structure, which they had in the plant leaf before treatment.

[0132] According to various embodiments, the plant leaf can, for example, come from local plants. For example, the plant leaf can come from a magnolia tree, rubber tree (e.g., Hevea brasiliensis), Bodhi tree (e.g., Ficus religiosa), rooibos (e.g., Fagus sylvatica), or from plants with large leaves (e.g., lotus, rhubarb, banana plants, etc.). The plant leaf can be washed before treatment, for example, using a solvent, such as an alcoholic solvent.

[0133] According to various embodiments, treating the plant leaf may comprise immersing the plant leaf in an alkaline medium, for example together with heating the plant leaf immersed in the alkaline medium (for example at a temperature in a range of 60°C to 100°C) to form the leaf structure. Example of providing the sheet structure 10

[0134] Magnolia leaves were freshly obtained from local plants and washed under running water before being placed in an ultrasonic bath containing ethanol for 10 minutes to remove impurities. The leaves were cut into 2.5 cm x 2.5 cm plates, and then the plates were placed in an aqueous solution of Na2CO3.10 H2O (sodium carbonate decahydrate / washing soda) in demineralized water and heated overnight at a constant temperature of 90°C with stirring (this process is also known as alkaline treatment). The amount of Na2CO3.10 H2O to be used was determined by simply increasing the amount until the compound no longer dissolved. The plates were then removed and placed in a separate container containing fresh distilled water at room temperature, which was then placed in an ultrasonic bath for 20 minutes.The entire process was repeated until the water no longer changed color after bathing. The leaf veins were clearly visible at this point (see ). Fig. 4A, B, and C) and light brushing with gloved fingers was sufficient to remove excess biomass. The leaf skeletons were then bleached in a 10% bleach solution for 15 minutes before being dried and smoothed with weights.

[0135] Fig. Figure 4B shows a cut plate of the magnolia leaf after alkaline treatment. Fig. Figure 4C shows the treated magnolia leaf under magnification (scale bar - 500 µm).

[0136] In an exemplary implementation, the base layer is provided by a flexible, freestanding porous structure (e.g., the leaf skeleton), which is coated (e.g., impregnated) with one or more functional materials by immersion in a coating liquid to promote an improved cell assembly (e.g., thin-film battery / capacitor designs). Optionally, the flexible, freestanding porous structure can be a freestanding leaf-based scaffold, which is more cost-effective, for example, than a fiberglass separator.

[0137] Fig. 5 illustrates the discharge curve of an exemplary electrochemical cell according to various embodiments (e.g., according to any one of Examples 1 to 4) in a schematic diagram 500. Fig. 6A and B each illustrate details of this discharge curve in various schematic diagrams 600a and 600b.

[0138] As can be seen, the electrochemical cell can be designed not only as primary batteries but also as secondary rechargeable cells, for example, based on a redox flow mechanism, such as the redox flow mechanism based on zinc and bromine. Other examples of the redox flow mechanism are based on vanadium, polysulfide and bromide, sodium chloride, or uranium.

[0139] Furthermore, the cell provided herein makes it possible to dispense with the need for constant circulation of the electrolyte using external pumps, as is often required in conventional redox flow cells. This is facilitated, for example, if the base layer contains one or more halogen complexing agents, which help limit bromine gas accumulation and generate stable cell performance. Examples of the halogen complexing agent include: 1-butyl-3-methylpyridinium bromide; N-ethyl-N-methylpyrrolidinium bromide; N-ethyl-N-methylmorpholinium bromide; 1-ethylpyridinium bromide; and 1-ethyl-3-methylimidazolium bromide ([C2MIm]Br).

[0140] Fig. 7 illustrates the discharge curve of an exemplary capacitor according to various embodiments (e.g., according to any one of Examples 1 to 4) in a schematic diagram 700. As can be seen, the capacitor falls into the category of supercapacitors, which have a particularly high energy density.

[0141] As explained above, Fig. 8A and Fig. 8B each show a cell of different architecture types according to various embodiments in a schematic side view or cross-sectional view.

[0142] Fig. 9A to C illustrate various implementations of the separator 106 (or at least the base layer thereof) according to various embodiments, respectively, in a schematic cross-sectional view (looking along the reference direction 101), in which the sheet structure is or will be coated, e.g., with a coating material 902, with an additional sheet structure 10 and / or with a polymer layer 914.

[0143] Implementation 900a (see Fig. 9A) of the separator 106 has a plurality of leaf veins, each of which is enveloped by a material 902 (also referred to as a coating material), e.g., coated therewith. The coating material 902 may comprise carbon, e.g., a polymer comprising carbon and / or a carbon modification. The composite of the coating material 902 and the leaf structure 10 coated therewith may be penetrated by the plurality of channels 904, e.g., from the top side to the bottom side.

[0144] An exemplary implementation of the coating material 902 may comprise or consist of a polymer, e.g., chitosan and / or cellulose and / or at least one derivative thereof (e.g., ethylcellulose), or at least forming a polymer layer. An alternative implementation of the coating material 902 may comprise or consist of fullerenes.

[0145] An exemplary implementation of the coating material 902 may be configured to provide a positive charge in aqueous solution (to attract negatively charged metal ions), e.g., configured as a positively charged polymer coating 902. Coating with the positively charged polymer coating 902 may be replaced if the metal is coated with a positively charged material (e.g., amines). In this case, the coating material 902 may also be negatively charged (e.g., comprising cellulose and / or at least one derivative thereof (e.g., ethylcellulose).

[0146] For example, the leaf veins can be coated with the coating material 902 by means of liquid-phase deposition, for example, by means of dip coating. Alternatively or additionally, any other coating process can of course be used to coat the leaf veins with the coating material 902, for example, vapor deposition, spray coating, particle deposition (e.g., powder coating), printing (e.g., stamping), lamination, etc.

[0147] Implementation 900b (see Fig. 9B) of the separator 106 has a stack 30s (also referred to as a sheet structure stack 30s) comprising a plurality of sheet structures 10 arranged one above the other (also referred to as stacked). Illustratively, a sheet structure 10 can be coated with one or more additional sheet structures 10 to form the sheet structure stack 30s. Optionally, the sheet structure stack 30s can be joined together (e.g., laminated and / or by crosslinking the coating material 902), e.g., by heating and / or by coating the sheet structure stack 30s, so that a laminate comprising a plurality of sheet structures 10 is formed. For example, one or more of the plurality of sheet structures 10 can be coated with the coating material 902, e.g., before or after they are arranged one above the other. The sheet structure stack 30s can be penetrated by the plurality of channels 904, e.g., from its top side to its bottom side.

[0148] The coating material 902 can comprise or consist of chitosan, cellulose, or cross-linked PVA. For example, the coating material forms a porous framework between the leaf veins 30. Using chitosan as an example, the porosity can be promoted by the chitosan polymer layer comprising or consisting of: nanoscale chitosan allotropes, such as nanoparticles, nanofibers, nanotubes, nanowires, nanocapsules, or nanolayer laminates, which can be produced synthetically, for example. The allotropes can be used to adjust the porosity of the chitosan polymer layer. Furthermore, it is possible to influence the porous structure of the chitosan polymer layer by means of chemical additives. Alternatively or additionally, the porosity can be influenced by thermoplastic deformation, e.g., by heating the layer. These processes can also be applied analogously to polymer coatings of other compositions (e.g.,made of cellulose and / or PVA). A change in the degree of porosity is also possible by influencing the degree of crosslinking and / or the crosslinking method. The advantage of porosity is that layer 902 contributes to confining the electrolyte between the pores of the leaf skeleton. Implementation 900c (see . Fig.9C) of the separator 106 has a stack 40s (also referred to as layer stack 40s) comprising at least one sheet structure 10 (e.g., a sheet structure stack 30s) and one or more chitosan polymer layers 914 with which the at least one sheet structure 10 is coated. The coating material 902 can optionally be arranged between the chitosan polymer layer 914 and the leaf veins (e.g., when the sheet structure 10 is coated according to implementation 900a). For this purpose, a layer stack 40s can be formed from the sheet structure 10 (e.g., coated with the coating material 902) and the chitosan polymer layer 914, for example, by stacking them (and, e.g., joining them together). The chitosan polymer layer 914 can, for example, be formed on a (e.g., planar) supporting surface (e.g., a substrate 50, for example, made of glass) (e.g., by means of a liquid phase coating).

[0149] For example, the leaf structure 10 (e.g., coated with the coating material 902) can be placed on the chitosan polymer layer 914 to form the layer stack 40s. Subsequently, the layer stack 40s can be detached from the support surface, for example, using ultrasound. The resulting separator 106, which comprises the layer stack 40s, can, for example, have a very homogeneous and smooth chitosan polymer layer 914.

[0150] More generally, the polymer layer 914 may have one or more of the following properties: - smooth to facilitate subsequent printing processes; - nanoporous to absorb electrolyte; - a smaller porosity than the coating material 902 to promote a smooth surface for printing; - Degree of nanoporosity can be in a range from about 10 nm to about 100 nm;

[0151] Examples of materials of the polymer layer 914 include: chitosan, cellulose, polyvinyl alcohol (PVA), polyvinylidene fluoride (PVDF), graphene oxide, and allotropes of these materials, e.g., comprising chitosan sheets and / or fibers.

[0152] Optionally, the layer stack 40s can be joined together, e.g. by heating and / or irradiating the stack.

[0153] An example of one of the exemplary implementations 900a, 900b, 900c includes coating the leaf structure with the coating material 902, for example, such that the leaf veins are coated with the coating material 902. Furthermore, the result of the coating (e.g., the separator or at least the base layer), which comprises the leaf structure 10 coated with the coating material 902, may be penetrated by multiple channels. The more or larger the channels 904 are present, the greater the porosity of the leaf structure 10 coated with the coating material 902.

[0154] One example of coating with the coating material 902 involves stimulating crosslinking of the coating material (also referred to as crosslinking). Crosslinking can occur by linking a plurality of individual macromolecules of the coating material 902 to form a three-dimensional network. Stimulating crosslinking of the coating material can occur by heating and / or irradiation. Heating can occur, for example, by supplying thermal energy to the coating material 902, for example, by means of a heating device. Irradiation can occur, for example, by irradiating the coating material 902 with electromagnetic radiation, for example, with ultraviolet radiation and / or with infrared radiation. Alternatively or additionally, crosslinking can occur chemically, e.g., by using oxidative or enzymatic polymerization.

[0155] The further the crosslinking of the coating material has progressed, the smaller the porosity of the sheet structure 10 coated with the coating material 902 can be.

[0156] In one example of crosslinking that may be performed in one of the exemplary implementations 900a, 900b, 900c, the crosslinking is controlled and / or regulated. This facilitates providing a resulting porosity according to a specification. The specification may, for example, comprise a desired state of the porosity and / or represent at least one parameter associated therewith, such as gas permeability. For example, the specification may comprise or at least represent a desired state for a gas permeability of the separator 106 or at least of the sheet structure 10 coated with the coating material 902.

[0157] For example, a parameter for stimulating cross-linking can be changed based on an actual state of cross-linking, e.g., its difference from the specification.

[0158] According to various embodiments, a process (or at least the device by which the process is performed) by which crosslinking is stimulated can be calibrated. Calibration may involve changing a duration and / or an intensity of the process based on the specification, the porosity, and / or based on the gas permeability. Once the process is calibrated, this facilitates the production of a variety of separators of the same quality.

Claims

[1] Using a leaf structure (10) of organic origin to form a separator (106) of an electrical cell (100a, 100b), wherein the leaf structure (10) is a plant leaf skeleton. [2] Using the sheet structure (10) according to claim 1, wherein the sheet structure (10) is coated with a portion of the separator (106), preferably by means of liquid phase deposition and / or on both sides. [3] Using the sheet structure (10) according to claim 1 or 2, wherein the electrical cell (100a, 100b) has one or more than one electrode (104l, 104r) with which the sheet structure (10) is coated, preferably on both sides. [4] Using the sheet structure (10) according to any one of claims 1 to 3, wherein the electrical cell (100a, 100b) has one or more than one electrode (104l, 104r), • into which the leaf structure (10) extends; • and / or which extends into a portion of the separator (106). [5] Using the leaf structure (10) according to one of claims 1 to 4, wherein the leaf structure (10) is flexible and / or of plant origin. [6] Using the sheet structure (10) according to one of claims 1 to 5, wherein the sheet structure (10) and / or the separator (106) are gas permeable. [7] Using the sheet structure (10) according to any one of claims 1 to 6, wherein the separator (106) is conductive to ions and / or porous. [8] Using the sheet structure (10) according to any one of claims 1 to 7, wherein forming the separator (106) comprises coating the sheet structure with a polymer, preferably cellulose, more preferably ethylcellulose. [9] Using the sheet structure (10) according to claim 8, wherein the polymer is or becomes crosslinked, preferably by irradiating the polymer and / or by heating the polymer. [10] Using the sheet structure (10) according to claim 9, further comprising calibrating a process by which the polymer is crosslinked based on a parameter representing a gas permeability of the separator (106). [11] Using the sheet structure (10) according to any one of claims 1 to 10, wherein forming the separator (106) comprises coating the sheet structure with one or more additional sheet structures. [12] Using the sheet structure (10) according to any one of claims 1 to 11, wherein forming the separator (106) comprises coating the sheet structure with chitosan. [13] Electric cell (100a, 100b), comprising: • a first electrode (104l); • a second electrode (104r); • a separator (106) which is arranged at least in sections between the first electrode (104l) and the second electrode (104r); • wherein the separator (106) is formed by means of a sheet structure (10) of organic origin, • wherein the leaf structure (10) is a plant leaf skeleton. [14] Method (300), comprising: • Forming a first electrode; • Forming a second electrode; • forming a separator (106) disposed between the first electrode and the second electrode; • wherein a sheet structure (10) of organic origin is used to form the separator (106), • wherein the leaf structure (10) is a plant leaf skeleton.

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