Multimodal silicon-carbon composite material, anode containing same and method for producing same - Patents.com

Abstract

This specification includes micropores and mesopores, and has a total pore volume of 0.5 cm 3 / g or more, a plurality of particles having a silicon content of 30% to 70% and a Dv50 of 6 μm to 20 μm; a first silicon-carbon composite material including micropores and mesopores and a total pore volume of 0.5 cm 3 / g or more, a plurality of particles having a silicon content of 30% to 70%, and a Dv50 of 1 μm to 6 μm; and 10% to 90% by weight of the first silicon-carbon composite material and 10% to 90% by weight of the second silicon-carbon composite material. Also disclosed are methods of making the silicon-carbon composite material, methods of making an anode electrode comprising the silicon-carbon composite material, and methods of making an electrochemical energy storage device comprising the silicon-carbon composite material.

Description

[Technical field]

[0001] The present disclosure relates to a particulate silicon-carbon composite blend having a multimodal particle size distribution. The present disclosure further relates to a method for making the silicon-carbon composite blend, a method for making an electrode including the silicon-carbon composite blend, and a method for employing the silicon-carbon composite blend as an anode in a lithium-based energy storage device, and an electrochemical energy storage device including the silicon-carbon composite blend. [Background technology]

[0002] Silicon-carbon composite mixtures can be made from carbon materials that contain pore volumes that include micropores, mesopores, and / or macropores. Such carbon mixtures can serve as scaffolds for making silicon-carbon composites. Methods for impregnating the pore volumes of porous carbon materials with silicon are known. The impregnated silicon can be provided in nano-size. In general, silicon has a significantly higher energy density than graphite and the like. For example, the energy density of silicon exceeds that of graphite by a factor of 10.

[0003] Upon further impregnation, such impregnated carbon materials may be coated so as to further reduce the still present porous surface. Possible coatings may consist, for example, of polymers, in particular conductive polymers, carbon or metal oxides. An advantage of impregnated and / or coated carbon materials is the increased stability of the lithium ion storage capacity, which increases the charging capacity of lithium ion battery cells.

[0004] Furthermore, the silicon-impregnated carbon material may be combined with other materials as a material composition. Known material compositions include binders and / or carbon particles. Such material compositions are typically utilized as electrode materials, particularly anode materials, in electrochemical cells, particularly lithium-ion battery cells.

[0005] In addition to silicon, such material compositions may contain other materials such as tin or other electrochemical modifications with lithium alloys. Lithium alloys may store large amounts of lithium per unit weight, depending on the alloy. However, the practical use of such alloys is limited due to the strong volume expansion that occurs during the complete reaction with lithium. Removal of lithium leads to volume expansion, while removal of lithium from silicon leads to volume contraction. This effect reduces the life and performance of the corresponding electrodes.

[0006] To overcome these shortcomings of lithium alloys, attempts have been made to increase the content of electrochemical alloy modifiers in the anode composition without affecting cycling stability.

[0007] This can be achieved by micro- or nano-structured electrochemical alloy modifiers, composites of the electrochemical alloy modifiers with carbon, or deposition of the electrochemical alloy modifiers on carbon using vacuum conditions or high temperature treatment. However, none of these methods can eliminate the impact on cycling stability. In particular, electrochemical cells are still susceptible to capacity fade with increasing cycle count, where a solid electrolyte interphase (SEI layer) forms on the negative electrode based on a variety of different mechanisms, competing with reversible lithium intercalation.

[0008] The SEI layer is usually formed by the reduction of organic solvents and anions on the electrode surface during the charge-discharge cycle of an electrochemical cell. In such cases, most of the formation occurs already during the first charge-discharge cycle of the electrochemical cell. In the prior art, it is known that the SEI layer plays an important role in terms of the safety, performance and cycle life of electrochemical cells, such as Li-ion battery cells.

[0009] The SEI layer causes irreversible consumption of lithium ions from the cathode at the anode, which typically results in capacity loss during the first lithiation / delithiation cycle. As the SEI layer continues to grow, the resistance of lithium ions to diffusion through it also increases.

[0010] Silicon tends to expand and contract continuously, leading to cracks and reformation, so different sizes and shapes of silicon are used to prevent this.Thus, different sizes and shapes of silicon are already known in the prior art.In particular, it is known in the prior art that the nanoscale-based characteristics of silicon are advantageous for use in electrochemical cells, especially Li-ion batteries.

[0011] For example, U.S. Patent Publication No. 2017 / 0170477 discloses a composite material comprising a porous carbon scaffold and silicon, the composite material comprising 15 to 85 wt. % silicon and 0.05 cm 3 / g~0.5cm 3 / g and the composite has a nitrogen inaccessible volume in the range of 1.5 g / cm as measured by helium pycnometry. 3 ~2.2g / cm 3 The particle scaffold density ranges from 0.01 to 0.01.

[0012] Due to the rapidly growing importance of electrochemical batteries, and in particular lithium-ion batteries, there is a continuing need for further developments and improvements in the field of silicon-carbon composites, both in the materials and in the methods for manufacturing such materials. [Prior art documents] [Patent documents]

[0013] [Patent Document 1] US Patent Publication No. 2017 / 0170477 Summary of the Invention

[0014] It is therefore an object of the present disclosure to provide a composite material mixture for electrodes as well as for electrochemical storage devices such as lithium ion batteries, having improved electrochemical properties.

[0015] This object is solved by providing a silicon-carbon composite mixture having a multimodal particle size distribution. The particle size distribution can be measured as known in the art. For example, the particle size distribution can be measured by laser light scattering of particles in a suspension, or powder time-of-flight, or other methods known in the art. The particle size distribution can be expressed as a number particle distribution or a volume particle distribution, as known in the art. Thus, the particle size distribution can be expressed as Dvx, where D represents the particle diameter, v represents the value corresponding to the volume basis, and x represents the cumulative % of the particles. For example, Dv1, Dv10, Dv50, Dv90, and Dv99 are the diameters at which 1%, 10%, 50%, 90%, and 99% of the particles in a given volume distribution are below a specified micron size. The particle size distribution is bounded by D0 (the smallest particle in the distribution) and Dv100 (the maximum size of the largest particle), and Dv50 is the volume average particle size. A particle size distribution can be described in terms of one or more modes present in the particle size distribution, where the concept of mode is known in the art, e.g., a local maximum in a distribution. The particle size distribution may be unimodal or multimodal, such as bimodal or trimodal. A mode in a multimodal particle size distribution may have distinct local maxima in the particle size distribution and / or shoulders that can be resolved from the first and / or second derivative of the particle size distribution.

[0016] Due to the rapidly growing importance of electrochemical batteries, and in particular lithium-ion batteries, there is a continuing need for further developments and improvements in the field of silicon-carbon composites, both in the materials and in the methods for manufacturing such materials.

[0017] It is therefore an object of the present disclosure to provide electrode and composite material mixtures for electrochemical storage devices, such as lithium ion batteries, having improved electrochemical properties.

[0018] Each embodiment herein includes a mixture that includes two or more silicon-carbon composite materials, each material having a different Dv50 or range of Dv50.

[0019] Thus, one embodiment includes (a)(i) a porous membrane comprising micropores and mesopores and having a total pore volume of 0.5 cm 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% by weight to 90% by weight of a first silicon-carbon composite material and 10% by weight to 90% by weight of a second silicon-carbon composite material. The present invention provides a silicon-carbon composite material comprising:

[0020] In a further embodiment, the blended material may optionally comprise a third or more silicon-carbon composites, each of the third or more silicon-carbon composites having a Dv50 of 1 μm to 6 μm. Thus, the silicon-carbon composite may comprise at least one further silicon-carbon composite, the at least one further silicon-carbon composite comprising micropores and mesopores and having a total pore volume of 0.5 cm3. 3 / g or more, with a silicon content of 30% to 70% and a Dv50 of 1 μm to 6 μm.

[0021] In one embodiment, the silicon-carbon composite mixture may comprise 10% to 90% by weight of a first silicon-carbon composite and 10% to 90% by weight of a second silicon-carbon composite or at least one further silicon-carbon composite.

[0022] One additional embodiment comprises: (a)(i) A micropore and a mesopore having a total pore volume of 0.5 cm 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% to 90% by weight of a first silicon-carbon composite material and 10% to 90% by weight of a second silicon-carbon composite material; (d) 30m 2 / g surface area, and (e) E greater than 0.01 [where E is 1-(tap density of composite mixture) / (mass average tap density of individual fractions) is defined as: Including, (f) providing a silicon-carbon composite mixture, measuring the tap density of the silicon-carbon composite mixture and measuring the tap densities of individual fractions comprising each mode under otherwise identical conditions to determine E;

[0023] Another embodiment is (a)(i) A micropore and a mesopore having a total pore volume of 0.5 cm3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% to 90% by weight of a first silicon-carbon composite material and 10% to 90% by weight of a second silicon-carbon composite material; (d) any third or more silicon-carbon composite materials, each having a different Dv50; (e) 30m 2 / g, and (e) E greater than 0.01 [where E is 1-(Conductivity of composite mixture) / (Mass average conductivity of individual fractions) is defined as: The present invention provides a silicon-carbon composite material comprising:

[0024] As used herein, "different Dv50" means that the third or more silicon-carbon composites or at least one further silicon-carbon composite comprises a plurality of particles having a Dv50 between 1 μm and 6 μm.

[0025] The silicon-carbon composite mixture, in one embodiment, may comprise 10% to 90% by weight of a first silicon-carbon composite and 10% to 90% by weight of a second silicon-carbon composite or at least one further silicon-carbon composite.

[0026] Yet another embodiment comprises: (a) providing a porous carbon scaffold; (b) Milling the porous carbon scaffold; (i) a first porous carbon composite material including a plurality of particles having a Dv50 of 6 μm to 20 μm; (ii) a second porous carbon composite material having a particle size distribution of Dv50=1 μm to 6 μm; generating at least two fine particle fractions comprising: (c) impregnating the pores of at least two particulate fractions of the porous carbon composite with silicon by chemical vapor infiltration; and (d) blending the first silicon-carbon composite material and the second silicon-carbon composite material. The present invention provides a method for producing a silicon-carbon composite blend, comprising:

[0027] Yet another embodiment comprises: (a) providing a porous carbon scaffold; (b) Milling the porous carbon scaffold; (i) a first porous carbon composite material including a plurality of particles having a Dv50 of 6 μm to 20 μm; (ii) a second porous carbon composite material having a particle size distribution of Dv50=1 μm to 6 μm; generating at least two fine particle fractions comprising: (c) impregnating the pores of at least two particulate fractions of the porous carbon composite with silicon by chemical vapor infiltration; (d) applying a coating to the surface of at least two particulate fractions of the porous silicon-carbon composite material by chemical vapor deposition; and (e) blending the first particulate silicon-carbon composite material and the second particulate silicon-carbon composite material to produce a blended material. The present invention provides a method for producing a silicon-carbon composite blend, comprising:

[0028] In further embodiments, the blended material may optionally include a third or more silicon-carbon composite materials, each of the third or more silicon-carbon composite materials having a unique Dv50.

[0029] As used herein, "intrinsic Dv50" means that the third or more silicon-carbon composite materials or at least one additional silicon-carbon composite material comprises a plurality of particles having a Dv50 of from 1 μm to 6 μm.

[0030] One embodiment comprises: (a)(i) A micropore and a mesopore having a total pore volume of 0.5 cm 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% by weight to 90% by weight of a first silicon-carbon composite material and 10% by weight to 90% by weight of a second silicon-carbon composite material. The present invention provides an anode electrode comprising a silicon-carbon composite mixture comprising:

[0031] The term carbon refers to a material or substance that consists of or at least includes carbon. In this regard, carbon materials may include high purity, amorphous and crystalline materials. The carbon may be activated carbon, pyrolyzed dried polymer gel, pyrolyzed polymer cryogel, pyrolyzed polymer xerogel, pyrolyzed polymer aerogel, activated dried polymer gel, activated polymer cryogel, activated polymer xerogel, activated polymer aerogel, or combinations thereof. In one embodiment, the carbon material has a high micropore volume ratio. In a further embodiment, the carbon can be produced by pyrolysis of coconut shells or other organic waste. In this respect, a polymer is a molecule that contains two or more repeating structural units. Porous carbon usually has the advantages of being easy to produce, having few impurities, and having a large pore volume. As a result, porous carbon exhibits good electrical conductivity and high mechanical and chemical stability.

[0032] Porous carbon typically has pore space, also called pore volume, which are the voids (pores) in the carbon that can be filled with a gas or fluid.

[0033] The silicon portion may be pure silicon or a material composition that includes silicon. For example, the silicon portion may be at least one alloy. The alloy may be a silicon-titanium alloy (Si-Ti), a silicon-iron alloy (Si-Fe), a silicon-nickel alloy (Si-Ni). In further embodiments, the silicon portion may be comprised of a P-dopant, an As-dopant, or an N-dopant. The P-dopant is typically a phosphorus dopant, the As-dopant is typically an arsenic dopant, and the N-dopant is typically a nitrogen dopant.

[0034] The silicon content of the multimodal silicon-carbon composite material in its total mass is usually between 30% and 70%, in particular between 40% and 60%.

[0035] In a further embodiment, the silicon-carbon composite mixture has a surface area of ​​30 m 2 / g. The surface area is measured by gas adsorption according to the BET measurement method, which is the term for an analytical method for determining the size of surfaces, especially porous solids. In a further embodiment, the BET surface area is less than 5 m 2 / g~25m 2 / g.

[0036] In a further embodiment, the anode electrode has a density comprising E greater than 0.01, where E is 1-(density of composite mixture) / (mass average density of individual fractions) where the density is the electrode density measured in an electrode composed of 70 wt. % composite, 20 wt. % graphite, 2 wt. % Super C65, and 8 wt. % PAA.

[0037] In a further embodiment, to determine E, measurements of the electrode properties of the silicon-carbon composite mixture and individual fractions comprising each mode are measured under otherwise identical conditions.

[0038] In a further embodiment, the anode electrode has a density with E greater than 0.01, where E is 1-(tap density of composite mixture) / (mass average tap density of individual fractions) where the density is the electrode density measured in an electrode composed of 70 wt. % composite, 20 wt. % graphite, 2 wt. % Super C65, and 8 wt. % PAA.

[0039] To determine E, measurements of the electrode properties of the silicon-carbon composite mixture and the individual fractions comprising each mode are measured under otherwise identical conditions.

[0040] In a further embodiment, E is greater than 0.05. In a further embodiment, E is greater than 0.1.

[0041] In a further embodiment, the silicon-carbon composite mixture comprises at least one further carbon and / or at least one binder. A binder is a binding agent or binding material. Thus, a binder refers to a material that can hold together individual components, in particular particles, of a substance, such as carbon. Binders are usually arranged so that when particles are combined with the corresponding binder, agglomerates are formed, which can then be molded into new shapes.

[0042] In a further embodiment, the at least one further carbon and / or the at least one binder are dissolved in the aqueous medium.

[0043] In a further embodiment, the silicon-carbon composite mixture has a density of 1.05 g / cm 3 ~1.5g / cm 3 , or 1.1 g / cm 3 ~1.3g / cm 3 This has the advantage that the particles are in better contact with each other, improving the conductivity of the resulting electrode.

[0044] In a further embodiment, the silicon-carbon composite material has a conductivity in the range of 0.3 S / cm to 2 S / cm, or 0.5 S / cm to 1.2 S / cm, which has the advantage of reducing the resistance of the electrode and allowing for faster reaction of lithium ions with the silicon-carbon composite material, thus potentially improving the charging rate of the lithium ion cell.

[0045] In a further embodiment, the carbon is a hard carbon material, graphitic carbon, or a metal oxide. For example, the metal oxide is silicon oxide (SiO2). Alternatively, the metal oxide is titanium oxide (TiO2), tin oxide (SnO2), or other metal oxides. The hard carbon material is a non-graphitizable carbon material. Hard carbon has the advantage that it remains amorphous even at high temperatures (typically above 1500°C), whereas "soft" carbon crystallizes to graphite.

[0046] In one embodiment, the carbon may be modified hard carbon. Modified hard carbon is a composite material that includes both carbon, particularly hard carbon, and a lithium alloying material. The lithium alloying material may be silicon, tin, germanium, nickel, aluminum, manganese, alumina (Al2O3), titanium, titanium oxide, sulfur, molybdenum, arsenic, gallium, phosphorus, selenium, antimony, bismuth, tellurium or indium, or other metals or metalloids that can absorb lithium.

[0047] In a further embodiment, the binder is configured to bond the porous carbon and the silicon content of the first silicon-carbon composite, the porous carbon and the silicon-carbon portion of the further silicon-carbon composite, and / or the first silicon-carbon composite and the further silicon-carbon composite. In a further embodiment, the binder is adapted to bond the further material to at least one of the respective silicon-carbon composites. Thus, the binder is generally arranged to hold together the components of the silicon-carbon composite mixture of the electrode, which may be formed as an anode, and optionally the further carbon material.

[0048] In a further embodiment, the silicon-carbon composite mixture comprises at least one further binder. This has the advantage that the carbon increases the electrical conductivity of the electrode, resulting in improved electrical conductivity. The at least one further binder further supports mechanical stability. The further carbon may be a hard carbon material or graphitic carbon or a metal oxide.

[0049] In a further embodiment, the silicon-carbon composite mixture comprises at least two binders, a first binder arranged to bond the porous carbon and silicon-carbon portions of the first silicon-carbon composite to the porous carbon and silicon portions of the at least one additional silicon-carbon composite, and at least one additional binder arranged to bond the first silicon-carbon composite to the at least one additional silicon-carbon composite.

[0050] Optionally, the silicon-carbon composite material includes at least one further binder adapted to bind together the first material component and the at least one further material component.

[0051] In a further embodiment, the binder is a styrene butadiene gum / carboxymethyl cellulose (CMC / SBR) blend, polyacrylic acid (PAA) and / or lithium polyacrylate (LiPAA) or sodium polyacrylate (NaPAA). In an alternative embodiment, the binder is formed as a fluoropolymer, such as polytetrafluoroethylene (PTFE), perfluoroalkoxy polymer resin (PFA), fluorinated ethylene propylene (FEP), polyethylene tetrafluoroethylene (ETFE), polyvinyl fluoride (PVF), polyethylene chlorotrifluoroethylene (ECTFE), (polyvinylidene fluoride (PCDF)), (polychlorotrifluoroethylene (PCTFE)), trifluoroethanol, or a combination of at least one of these materials with at least one other material. In a further embodiment, the binder is a polyimide, or a copolymer of polyacrylic acid and styrene-butadiene. The present disclosure provides the advantage that the bimodal distribution of the composite allows for higher packing density and improved electrical conductivity of the anode electrode.

[0052] Yet another embodiment comprises: (a) mixing a silicon-carbon composite mixture with at least one carbon to form a mixture; (b) mixing the mixture and a binder solution in a twin screw extruder to form an electrode paste; (c) applying the electrode paste to a conductor to form at least one electrode; (d) drying the at least one electrode at a temperature between 100° C. and 140° C. The present invention provides a method for manufacturing an anode electrode comprising a silicon-carbon composite blend according to any one of the embodiments described herein, comprising:

[0053] One object of the present disclosure is to provide an electrical energy storage device (e.g., a lithium ion battery) comprising at least one anode electrode according to any one of the embodiments described herein.

[0054] Thus, another embodiment is (a) at least one anode electrode according to any one of the embodiments described herein; (b) at least one electrode configured as a cathode, the electrode comprising a transition metal oxide; (c) a separator disposed between the cathode and the anode; and (d) An electrolyte containing lithium ions The present invention provides an electrochemical storage device, in particular formed as a lithium ion battery, comprising:

[0055] Yet another embodiment is a silicon-carbon composite comprising: (a)(i) A micropore and a mesopore having a total pore volume of 0.5 cm 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% by weight to 90% by weight of a first silicon-carbon composite material and 10% by weight to 90% by weight of a second silicon-carbon composite material. The present invention provides a use of a silicon-carbon composite material mixture in an anode electrode, the use comprising:

[0056] In one further embodiment of such a use, the surface area of ​​the silicon-carbon composite mixture is 30 m2 / g.

[0057] In yet another embodiment, the silicon-carbon composite comprises: (a)(i) A micropore and a mesopore having a total pore volume of 0.5 cm 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% by weight to 90% by weight of a first silicon-carbon composite material and 10% by weight to 90% by weight of a second silicon-carbon composite material. Including, (d) providing a use of the silicon-carbon composite blend in an anode electrode, the anode being comprised of a first and a second layer, the first layer comprising a first silicon-carbon composite material and the second layer comprising a second silicon-carbon composite material.

[0058] In a further embodiment of such a use, the anode electrode has a density having an E greater than 0.01, where E is 1-(density of composite mixture) / (mass average density of individual fractions) where the density is the electrode density measured in an electrode composed of 70 wt. % composite, 20 wt. % graphite, 2 wt. % Super C65, and 8 wt. % PAA.

[0059] In one further embodiment of such a use, the determination of E of the silicon-carbon composite mixture and the individual fractions comprising each mode are measured under otherwise identical conditions.

[0060] In a further embodiment of such a use, E is greater than 0.05.In a further embodiment of such a use, E is greater than 0.1.

[0061] Yet another embodiment provides the use of an anode electrode comprising a silicon-carbon mixture of any one of the embodiments described herein in an electrochemical storage device. In one embodiment, the electrochemical storage device is a lithium ion battery. [Brief description of the drawings]

[0062] In the figures, identical reference numbers refer to similar elements. The sizes and relative positions of elements in the figures are not necessarily drawn to scale, and some of these elements have been enlarged and positioned to improve legibility in the figures. Furthermore, the particular shapes of the depicted elements are not intended to convey any information regarding the actual shape of the particular elements, but have been selected solely for ease of recognition in the figures. [Figure 1] A volumetric difference plot of silicon-carbon composite 22 (dashed line) and silicon-carbon composite 23 (solid line) is shown. [Diagram 2] 1 shows volume difference plots for various blends of silicon-carbon composite 22 and silicon-carbon composite 23: 10 / 90 (dashed line), 50 / 50 (solid line), and 90 / 10 (dotted line). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0063] In the following description, certain specific details are set forth in order to provide a thorough understanding of various embodiments of the present disclosure. However, it will be understood by those skilled in the art that the present disclosure may be practiced without these details.

[0064] Unless the context requires otherwise, throughout this specification and claims, the words "comprises" and "comprising" and variations thereof are to be interpreted in their open, inclusive sense, i.e., "including, but not limited to."

[0065] Any concentration range, percentage range, ratio range, or integer range herein is understood to include any integer value within the stated range, and fractions thereof, where appropriate (such as tenths and hundredths of integers), unless otherwise indicated. As used herein, the terms "about" and "approximately" mean ±20%, ±10%, ±5%, or ±1% of the indicated range, value, or structure, unless otherwise indicated. The terms "a" and "an" as used herein should be understood to mean "one or more" of the listed components. Use of the alternative (e.g., "or") should be understood to mean either one, both, or any combination of the alternatives.

[0066] References throughout this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment of the disclosure. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification do not necessarily all refer to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0067] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. As used in this specification and claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0068] The foregoing objectives are solved by a multimodal silicon-carbon composite having features of embodiments disclosed herein (the terms "multimodal silicon-carbon composite" and "silicon-carbon composite blend" may be used interchangeably in some embodiments). For example, one embodiment comprises: (a)(i) A micropore and a mesopore having a total pore volume of 0.5 cm 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% by weight to 90% by weight of a first silicon-carbon composite material and 10% by weight to 90% by weight of a second silicon-carbon composite material. The present invention provides a silicon-carbon composite material comprising:

[0069] In some embodiments, the silicon-carbon composite mixture is 30 ml 2 / g.

[0070] In some embodiments, E is greater than 0.01, where E is 1-(density of composite mixture) / (mass average density of individual fractions) where the density is the electrode density measured in an electrode composed of 70 wt. % composite, 20 wt. % graphite, 2 wt. % Super C65, and 8 wt. % PAA.

[0071] In some embodiments, E is greater than 0.01, where E is 1-(density of composite mixture) / (mass average density of individual fractions) It is defined as: Density = E(x,y) / 20%. In some embodiments, density is measured in an electrode composed of 70 wt% composite, 20 wt% graphite, 2 wt% Super C65, and 8% PAA. In some specific embodiments, to determine E, measurements of electrode properties of silicon-carbon composite mixture and individual fractions containing each mode are measured under otherwise identical conditions. In some embodiments, E is greater than 0.05. In some embodiments, E is greater than 0.1.

[0072] One embodiment comprises: (a)(i) A micropore and a mesopore having a total pore volume of 0.5 cm 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% to 90% by weight of a first silicon-carbon composite material and 10% to 90% by weight of a second silicon-carbon composite material; (d) 30m 2 / g surface area, and (e) E greater than 0.01 [where E is 1-(tap density of composite mixture) / (mass average tap density of individual fractions) is defined as: Including, (f) providing a silicon-carbon composite mixture, measuring the tap density of the silicon-carbon composite mixture and measuring the tap densities of individual fractions comprising each mode under otherwise identical conditions to determine E;

[0073] The tap density of particulate silicon-carbon composites and silicon-carbon composite blends can be measured as known in the art. For example, tap density can be measured using a PT-TD300 Tap Density Tester by loading a known mass of powder into a graduated cylinder, e.g., filling the graduated cylinder to 1 / 2 to 3 / 4 of its total capacity, loading the cylinder into a test device, tapping the loaded cylinder for a set number of taps (e.g., 250 taps), recording the new tap volume, and repeating this tapping process until the measured volume no longer changes, e.g., within 2% of the previous measurement.

[0074] In some embodiments, the tap density of the particulate silicon-carbon material ranges from 0.3 g / cc to 0.5 g / cc, or from 0.4 g / cc to 0.6 g / cc, or from 0.5 g / cc to 0.7 g / cc, or from 0.6 g / cc to 0.8 g / cc, or from 0.7 g / cc to 0.9 g / cc, or from 0.8 g / cc to 1.0 g / cc. In some embodiments, the tap density of the particulate silicon-carbon material is greater than 1.0 g / cc.

[0075] In some embodiments, the tap density of the particulate silicon-carbon mixture is in the range of 0.3 g / cc to 0.5 g / cc, or 0.4 g / cc to 0.6 g / cc, or 0.5 g / cc to 0.7 g / cc, or 0.6 g / cc to 0.8 g / cc, or 0.7 g / cc to 0.9 g / cc, or 0.8 g / cc to 1.0 g / cc. In some embodiments, the tap density of the particulate silicon-carbon mixture is greater than 1.0 g / cc.

[0076] Another embodiment is (a)(i) A micropore and a mesopore having a total pore volume of 0.5 cm 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% to 90% by weight of a first silicon-carbon composite material and 10% to 90% by weight of a second silicon-carbon composite material; (d) 30m 2 / g surface area, and (e) E greater than 0.01 [where E is 1-(Conductivity of composite mixture) / (Mass average conductivity of individual fractions) is defined as: The present invention provides a silicon-carbon composite material comprising:

[0077] In some specific embodiments, to determine E, measurements of properties of the silicon-carbon composite mixture and individual fractions comprising each mode are measured under otherwise identical conditions. In some embodiments, the conductivity is the conductivity measured in an electrode composed of 70 wt.% composite, 20 wt.% graphite, 2 wt.% Super C65, and 8 wt.% PAA. In some embodiments, E is greater than 0.05. In some embodiments, E is greater than 0.1.

[0078] One embodiment comprises: (a) providing a porous carbon scaffold; (b) Milling the porous carbon scaffold; (i) a first porous carbon composite material including a plurality of particles having a Dv50 of 6 μm to 20 μm; (ii) a second porous carbon composite material having a particle size distribution of Dv50=1 μm to 6 μm; generating at least two fine particle fractions comprising: (c) impregnating the pores of at least two particulate fractions of the porous carbon composite with silicon by chemical vapor infiltration; and (d) blending the first silicon-carbon composite material and the second silicon-carbon composite material. The present invention provides a method for producing a silicon-carbon composite blend, comprising:

[0079] In some embodiments, The mixture comprises a first fraction of the first silicon-carbon composite material in a proportion of 60% to 90% by weight and a further fraction of at least one further silicon-carbon composite material in a proportion of 10% to 40% by weight. In some more specific embodiments, the mixture comprises a first fraction of the first silicon-carbon composite material in a proportion of 70% to 90% by weight and a second silicon-carbon composite material in a proportion of 10% to 30% by weight.

[0080] Another embodiment is (a) providing a porous carbon scaffold; (b) Milling the porous carbon scaffold; (i) a first porous carbon composite material including a plurality of particles having a Dv50 of 6 μm to 20 μm; (ii) a second porous carbon composite material having a particle size distribution of Dv50=1 μm to 6 μm; generating at least two fine particle fractions comprising: (c) impregnating the pores of at least two particulate fractions of the porous carbon composite with silicon by chemical vapor infiltration; (d) applying a coating to the surface of at least two particulate fractions of the porous silicon-carbon composite material by chemical vapor deposition; and (e) blending the first particulate silicon-carbon composite material and the second particulate silicon-carbon composite material. The present invention provides a method for producing a silicon-carbon composite blend, comprising:

[0081] One specific embodiment is (a)(i) A micropore and a mesopore having a total pore volume of 0.5 cm 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% by weight to 90% by weight of a first silicon-carbon composite material and 10% by weight to 90% by weight of a second silicon-carbon composite material. A silicon-carbon composite mixture comprising: An anode electrode is provided, comprising:

[0082] In some embodiments, the silicon-carbon composite mixture is 30 ml 2In some embodiments, the silicon-carbon composite mixture has an E of greater than 0.01, where E is: 1-(density of composite mixture) / (mass average density of individual fractions) In some embodiments, E is defined as: 1-(tap density of composite mixture) / (mass average tap density of individual fractions) In some embodiments, the density is the electrode density measured in an electrode composed of 70% by weight composite, 20% by weight graphite, 2% by weight Super C65, and 8% by weight PAA.

[0083] In some embodiments, E is greater than 0.05. In some embodiments, E is greater than 0.1. In some embodiments, to determine E, measurements of the electrode properties of the silicon-carbon composite mixture and individual fractions comprising each mode are measured under otherwise identical conditions.

[0084] In more specific embodiments, the silicon-carbon composite mixture includes at least one additional carbon and / or at least one binder. In some more specific embodiments, the at least one additional carbon and / or the at least one binder are dissolved in the aqueous medium. In some embodiments, the silicon-carbon composite mixture has a water content of 1.05 g / cm. 3 ~1.5g / cm 3 , or 1.1 g / cm 3 ~1.3g / cm 3 The electron density is configured to be in the range of

[0085] In some embodiments, the silicon-carbon composite mixture has an electrical conductivity in the range of 0.3 S / cm to 2 S / cm, or 0.5 S / cm to 1.2 S / cm. In some embodiments, the carbon is a hard carbon material, graphitic carbon, or a metal oxide. In some more specific embodiments, a binder is configured to bond the porous carbon to the silicon-containing first silicon-carbon composite, the porous carbon to the silicon-carbon portion of the second silicon-carbon composite, and / or the first silicon-carbon composite to the second silicon-carbon composite. In more specific embodiments, the silicon-carbon composite mixture includes at least one additional binder. In some embodiments, the binder or additional binder is a styrene-butadiene gum / carboxymethyl cellulose (CMC / SBR) mixture, polyacrylic acid (PAA) and / or lithium polyacrylate (LiPAA) or sodium polyacrylate (NaPAA).

[0086] One specific embodiment is (a) mixing a silicon-carbon composite mixture with at least one carbon to form a mixture; (b) mixing the mixture and a binder solution in a twin screw extruder to form an electrode paste; (c) applying the electrode paste to a conductor to form at least one electrode; (d) drying the at least one electrode at a temperature between 100° C. and 140° C. The present invention provides a method for manufacturing an anode electrode comprising a silicon-carbon composite blend according to any one of the embodiments described herein, comprising:

[0087] One embodiment comprises: (a) at least one anode electrode according to any one of the embodiments described herein; (b) at least one electrode configured as a cathode, the electrode comprising a transition metal oxide; (c) a separator disposed between the cathode and the anode; and (d) An electrolyte containing lithium ions The present invention provides an electrochemical storage device, in particular formed as a lithium ion battery, comprising:

[0088] A further embodiment provides an anode electrode comprising the silicon-carbon mixture of any one of the embodiments described herein.

[0089] In one embodiment, the silicon-carbon composite material comprises: (a)(i) A micropore and a mesopore having a total pore volume of 0.5 cm 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% by weight to 90% by weight of a first silicon-carbon composite material and 10% by weight to 90% by weight of a second silicon-carbon composite material. The present invention provides a use of a silicon-carbon composite material mixture in an anode electrode, the use comprising:

[0090] In some embodiments, the silicon-carbon composite mixture is 30 ml 2 In some more specific embodiments, the silicon-carbon composite blend has an E of greater than 0.01, where E is: 1-(density of composite mixture) / (mass average density of individual fractions) where the density is the electrode density measured in an electrode composed of 70 wt.% composite, 20 wt.% graphite, 2 wt.% Super C65, and 8 wt.% PAA. In some more specific embodiments, the silicon-carbon composite blend has an E of greater than 0.01, where E is 1-(tap density of composite mixture) / (mass average tap density of individual fractions) It is defined as: In some embodiments, to determine E, measurements of the electrode properties of the silicon-carbon composite mixture and the individual fractions comprising each mode are measured under otherwise identical conditions. In some embodiments, E is greater than 0.05. In some embodiments, E is greater than 0.1.

[0091] In one embodiment, the silicon-carbon composite material comprises: (a)(i) A micropore and a mesopore having a total pore volume of 0.5 cm 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% by weight to 90% by weight of a first silicon-carbon composite material and 10% by weight to 90% by weight of a second silicon-carbon composite material. The present invention provides a use of a silicon-carbon composite material mixture in an anode electrode, the use comprising:

[0092] In some embodiments, the silicon-carbon composite mixture is 30 ml 2In some more specific embodiments, the silicon-carbon composite blend has an E of greater than 0.01, where E is: 1-(density of composite mixture) / (mass average density of individual fractions) where the density is the electrode density measured in an electrode composed of 70 wt.% composite, 20 wt.% graphite, 2 wt.% Super C65, and 8 wt.% PAA. In some more specific embodiments, the silicon-carbon composite blend has an E greater than 0.01, where E is 1-(tap density of composite mixture) / (mass average tap density of individual fractions) In more specific embodiments, E is greater than 0.05. In some embodiments, E is greater than 0.1.

[0093] An additional embodiment provides the use of an anode electrode according to any one of the embodiments described herein in an electrochemical storage device.

[0094] The carbon materials produced according to the compositions and methods described herein have improved electrochemical properties and are particularly applicable to a variety of electrical devices, especially Li-ion batteries.

[0095] According to one aspect of the present disclosure, a multimodal silicon-carbon composite material (silicon-carbon composite) for an electrode is provided. The multimodal silicon-carbon composite comprises a first silicon-carbon composite material comprising porous carbon and having a silicon content of 30% to 70%, the first silicon-carbon composite material comprising a first fraction having a particle size distribution of Dv50=7 μm to 20 μm, and at least one additional silicon-carbon composite material comprising the at least one porous carbon and having a silicon content of 30% to 70%, the additional silicon-carbon composite material having a further fraction having a particle size distribution of Dv50=2 μm to 6 μm, the multimodal silicon-carbon composite material comprising the first fraction of the first silicon-carbon composite material in a proportion of 70% to 90%, the additional silicon-carbon composite material having a proportion of 10% to 30%.

[0096] In some embodiments, the mass fraction of the first fraction of the first silicon-carbon composite material is between 10% and 90%, such as between 20% and 90%, such as between 30% and 90%, such as between 40% and 90%, such as between 50% and 90%, such as between 60% and 90%. Correspondingly, in some embodiments, the mass fraction of the additional silicon-carbon composite material is between 10% and 90%, such as between 10% and 80%, such as between 10% and 70%, such as between 10% and 60%, such as between 10% and 50%, such as between 10% and 40%.

[0097] In some embodiments, the mass fraction of the first fraction of the first silicon-carbon composite material is between 10% and 50%, such as between 20% and 50%, such as between 30% and 50%, such as between 40% and 50%. Correspondingly, in some embodiments, the mass fraction of the further fraction of the additional silicon-carbon composite material is between 50% and 90%, such as between 50% and 80%, such as between 50% and 70%, such as between 50% and 60%.

[0098] Typically, silicon in porous carbon is introduced into the pores of the porous carbon by chemical vapor infiltration (CVI) reaction of a silicon-containing gas, such as monosilane, e.g., silicon hydride (SiH4). A description of such a method is described in U.S. Patent Publication No. 2017 / 0170477, the entire disclosure of which is incorporated herein by reference in its entirety for all purposes.

[0099] Thus, the present subject matter relates to the particle size composition of a composite material. As used herein, multimodal means that the composite material comprises at least two fractions, each fraction being a respective predefined range of particle sizes in the particle size distribution.

[0100] The term carbon material refers to a material or substance that consists of or at least includes carbon. In this regard, carbon materials may include high purity, amorphous and crystalline materials. The carbon material may be activated carbon, pyrolyzed dried polymer gel, pyrolyzed polymer cryogel, pyrolyzed polymer xerogel, pyrolyzed polymer aerogel, activated dried polymer gel, activated polymer cryogel, activated polymer xerogel, activated polymer aerogel, or combinations thereof. In further embodiments, carbon can be produced by pyrolysis of coconut shells or other organic waste. In this regard, a polymer is a molecule that includes two or more repeating structural units.

[0101] Porous carbon, also known as porous carbon material, typically offers the advantages of easy production, low impurity content, and large pore volume. As a result, porous carbon exhibits good electrical conductivity and high mechanical and chemical stability. In one embodiment, the carbon material has a high micropore volume ratio.

[0102] Typically, porous carbon has pore space, also called pore volume, which are the voids (pores) in the carbon that can be filled with a gas or fluid.

[0103] In this regard, the properties of, and methods of manufacture of, porous carbon have been described in the prior art, e.g., U.S. Patent Publication No. 2017 / 0015559, the entire disclosure of which is incorporated herein by reference in its entirety for all purposes.

[0104] The Si portion may be pure silicon or a material composition including silicon. For example, the Si portion may be at least one alloy. The alloy may be a silicon-titanium alloy (Si-Ti), a silicon-iron alloy (Si-Fe), a silicon-nickel alloy (Si-Ni). In further embodiments, the Si portion may be comprised of a P-dopant, an As-dopant or an N-dopant. The P-dopant is typically a phosphorus dopant, the As-dopant is typically an arsenic dopant, and the N-dopant is typically a nitrogen dopant.

[0105] The silicon content of the multimodal silicon-carbon composite material in its total mass is typically 10%-90%, such as 20%-80%, such as 30%-70%, such as 40%-60%.

[0106] A binder is a binding agent or binding material. Thus, a binder refers to a material that can hold together individual components, especially particles, of a substance, such as carbon. Binders are usually arranged so that when particles are combined with a corresponding binder, an agglomerate is formed, which can then be molded into a new shape.

[0107] In one embodiment, the binder is a styrene butadiene gum / carboxymethyl cellulose (CMC / SBR) blend, polyacrylic acid (PAA) and / or lithium polyacrylate (LiPAA) or sodium polyacrylate (NaPAA). In an alternative embodiment, the binder is formed as a fluoropolymer, such as polytetrafluoroethylene (PTFE), perfluoroalkoxy polymer resin (PFA), fluorinated ethylene propylene (FEP), polyethylene tetrafluoroethylene (ETFE), polyvinyl fluoride (PVF), polyethylene chlorotrifluoroethylene (ECTFE), polyvinylidene fluoride (PCDF), polychlorotrifluoroethylene (PCTFE), trifluoroethanol, or a combination of at least one of these materials with at least one other material. In a further embodiment, the binder is a polyimide, or a copolymer of polyacrylic acid and styrene-butadiene.

[0108] The present disclosure provides the advantage that the bimodal distribution of the composite material allows for higher packing density and improved electrical conductivity of the anode electrode.

[0109] In a further embodiment, the multimodal silicon-carbon composite comprises at least one further carbon and / or at least one further binder. This has the advantage that the carbon increases the electrical conductivity of the electrode, resulting in improved electrical conductivity. The at least one further binder further supports mechanical stability. The further carbon may be a hard carbon material or graphitic carbon or a metal oxide.

[0110] In one embodiment, the at least one further carbon and / or the at least one further binder are dissolved in the aqueous medium.

[0111] In a further embodiment, the multimodal silicon-carbon composite has a silicon-carbon composite mass of 1.05 g / cm 3 ~1.5g / cm 3 , especially 1.1 g / cm 3 ~1.3g / cm 3This has the advantage that the particles are in better contact with each other, improving the conductivity of the resulting electrode.

[0112] In a further embodiment, the multimodal silicon-carbon composite is a multimodal silicon-carbon composite having a thickness of 4 mm. 2 / g~30m 2 / g, especially 8m 2 / g~20m 2 / g BET surface area (as measured by Brunauer Emmett Teller). BET surface area as measured by BET is a term for an analytical method for determining the size of surfaces, especially porous solids, by gas adsorption.

[0113] In a further embodiment, the BET surface area is 5 m 2 / g~25m 2 In a further embodiment, the silicon-carbon composite has an electrical conductivity of 0.3 S / cm to 2 S / cm, in particular 0.5 S / cm to 1.2 S / cm.

[0114] This has the advantage of reducing the resistance of the electrode and allowing the lithium ions to react more quickly with the multimodal Si-C composite, potentially improving the charging speed of lithium-ion batteries.

[0115] In one embodiment, the carbon is a hard carbon material, graphitic carbon or a metal oxide. For example, the metal oxide is silicon oxide (SiO2). Alternatively, the metal oxide is titanium oxide (TiO2), tin oxide (SnO2) or other metal oxides. The hard carbon material is a non-graphitizable carbon material. Hard carbon has the advantage that it remains amorphous even at high temperatures (typically above 1500°C), whereas "soft" carbon crystallizes to graphite.

[0116] In one embodiment, the carbon may be modified hard carbon. Modified hard carbon is a composite material that includes both carbon, particularly hard carbon, and a lithium alloying material. The lithium alloying material may be silicon, tin, germanium, nickel, aluminum, manganese, alumina (Al2O3), titanium, titanium oxide, sulfur, molybdenum, arsenic, gallium, phosphorus, selenium, antimony, bismuth, tellurium or indium, or other metals or metalloids that can absorb lithium.

[0117] In further embodiments, the binder is configured to bond the porous carbon and the Si portion of the first silicon-carbon composite, the porous carbon and the silicon-carbon portion of the further silicon-carbon composite, and / or the first silicon-carbon composite and the further silicon-carbon composite.

[0118] In a further embodiment, the binder is adapted to bond the further material to at least one of the respective silicon-carbon composites. Thus, the binder is generally arranged to hold together the multimodal silicon-carbon composite components and any further carbon materials of an electrode, which may be formed as an anode.

[0119] In a further embodiment, the multimodal silicon-carbon composite comprises at least two binders, a first binder arranged to bond the porous carbon and the silicon-carbon portion of the first silicon-carbon composite and the porous carbon and the Si portion of the second silicon-carbon composite, and at least one further binder arranged to bond the first silicon-carbon composite to the second silicon-carbon composite.

[0120] Optionally, the silicon-carbon composite material includes at least one further binder adapted to bind together the first material component and the at least one further material component.

[0121] According to a further aspect of the present disclosure, there is provided an anode comprising at least one silicon-carbon composite multimodal material as described above.

[0122] According to a further aspect of the present disclosure, there is provided a method for producing the aforementioned silicon-carbon composite material. In a first step, a porous carbon scaffold material is produced. In a preferred embodiment, the carbon scaffold is made according to the aforementioned US Patent Publication No. 2017 / 0015559. In a preferred embodiment, the porous carbon scaffold carbon is an amorphous carbon containing nitrogen. The use of nitrogen (N) improves the electrical conductivity of the amorphous carbon. In some embodiments, the polymer gel is pyrolyzed in nitrogen at a temperature of 700° C. to 950° C. to obtain the silicon-carbon composite material.

[0123] In a preferred embodiment, the porous carbon scaffold comprises micropores, mesopores, and / or macropores, where micropores are defined as pores with a diameter less than 2 nm, mesopores are defined as pores with a diameter between 2 nm and 50 nm, and mesopores are defined as pores with a diameter greater than 50 nm. As used herein, % "microporosity", % "mesoporosity", and % "macroporosity" refer to the percentage of micropores, mesopores, and macropores, respectively, relative to the total pore volume. For example, a carbon scaffold with a microporosity of 90% is a carbon scaffold in which 90% of the total pore volume of the carbon scaffold is micropores.

[0124] In a further step, the silicon-carbon composite is pulverized by grinding to produce at least two silicon-carbon composites, each of the two silicon-carbon composites having a unique average particle size. In particular, one of the at least two silicon-carbon composites has a particle size distribution with a percentile of Dv50=6 μm to 20 μm, and the second silicon-carbon composite has a particle size distribution with a percentile of Dv50=1 μm to 6 μm. Such pulverization can be achieved by attrition-type grinding methods, such as particle size reduction using a hammer mill, ball mill, jet mill, or other attrition-type mill, as known in the art.

[0125] The two or more fractions of the silicon-carbon composite each include a porous carbon scaffold having certain properties, such as those disclosed in the aforementioned U.S. Patent Publication No. 2017 / 0170477. Exemplary properties are shown in Table 1. TIFF2024540577000002.tif189147

[0126] In a further step, at least two of the carbon scaffold fractions are subjected to a CVI process to impregnate the pores of the porous carbon with silicon, a description of which is given in the aforementioned U.S. Patent Publication No. 2017 / 0170477.

[0127] It is a further object of the present disclosure to provide a method for making an anode electrode comprising the aforementioned silicon-carbon composite mixture.

[0128] In a first step, the manufacturing method comprises mixing the Si-C composite material with at least one carbon. In a further step, the mixture and a binder solution are combined in a twin screw extruder to form an electrode paste. The binder solution in this case is typically a binder dissolved in an aqueous solution. In a further step, the electrode paste is applied to a current conductor to produce at least one electrode. In a further step, the at least one electrode is dried at a temperature between 100°C and 140°C.

[0129] It is a further object of the present disclosure to provide an electrical energy storage device, in particular a lithium ion battery, comprising at least one anode electrode comprising the aforementioned multimodal silicon-carbon composite material, at least one cathode electrode comprising a transition metal oxide, a separator disposed between the cathode and anode electrodes, and an electrolyte comprising lithium ions.

[0130] Multimodal silicon-carbon composites, when processed into electrodes as described herein, provide surprising and unexpected results. For example, some beneficial properties of electrodes containing multimodal silicon-carbon composites exceed the mass average properties of the corresponding individual fractions containing multimodal silicon-carbon composites. Such properties include, but are not limited to, physicochemical properties such as density, and electrochemical properties such as electrical conductivity. The latter also provide a surprising and unexpected result of improved rate capability of the energy storage device comprising electrodes containing multimodal silicon-carbon composites.

[0131] Another improvement with respect to the multimodal silicon-carbon composite is observed in the increased C-rate capacity of the electrode fabricated with the multimodal silicon-carbon composite compared to the measurement of the electrode properties of the individual fractions. The charge-discharge C-rate enhancement is in the range of 3-30%, more preferably in the range of 5-15%. Similar electrode loadings and electrode fabrications were set up to measure the C-rate performance. The loading of the silicon-carbon composite and the individual fractions was 4.0 mAh / cm. 2 The electrode for measurement was prepared by mixing the active material with the carbon material and the binder dissolved in an aqueous solution. The ratio of the mixture was set to 70 wt% active material, 20 wt% graphite (KSL6, Imerys), 2 wt% Super C65 (Imerys), and 8% PAA dissolved in water. The active material in this experiment was a multimodal silicon-carbon composite or individual fractions. The electrolyte for this measurement was selected to be 1M LiPF6 dissolved in a 1:4 mixture of fluoroethylene carbonate and diethyl carbonate. In this experiment, the 1C rate current of the electrode was defined as 1800mAh.

[0132] Thus, an electrode comprising a silicon-carbon composite material has one or more properties having an enhancement factor, E, where: E = 1-(composite value) / (mass average of individual fractions) To determine E, measurements of the electrode properties of the multimodal silicon-carbon composite and the individual fractions comprising each mode are measured under otherwise identical conditions.

[0133] In some embodiments, the slurry mixture is applied to a current collector as known in the art following a coating, drying, and calendering sequence. The degree of calendering may be expressed as a percentage as the difference between the initial electrode thickness and the final electrode thickness divided by the initial electrode thickness. For example, if the initial electrode thickness (i.e., before calendering) is 50 μm and the final electrode thickness (i.e., after calendering) is 40 μm, the degree of calendering is 20%. In some embodiments, the degree of calendering is between 10% and 50%, such as between 15% and 40%, such as between 15% and 30%. In further embodiments, the final electrode comprises a first slurry mixture comprising a first Si—C composite material having a first average particle size applied to the current collector and optionally dried and calendered. The electrode further comprises a second slurry mixture comprising a second Si—C composite material having a second average particle size applied to the current collector and optionally dried and calendered. This electrode stacking process is optionally repeated with additional or two more Si-C composite materials to create a stacked electrode.

[0134] In some embodiments, E for one or more electrode properties is greater than 0.01, such as greater than 0.02, for example greater than 0.05, such as greater than 0.1, for example greater than 0.15, such as greater than 0.2, for example greater than 0.3, such as greater than 0.4, for example greater than 0.5, such as greater than 0.6, for example greater than 0.8, such as greater than 1.0, for example greater than 1.2, such as greater than 1.5, for example greater than 2.0. EXAMPLES

[0135] Example 1: Preparation of silicon-carbon composite material by CVI The properties of the carbon scaffold (Carbon Scaffold 1) employed in the preparation of silicon-carbon composites are shown in Table 2. Carbon Scaffold 1 is used to prepare silicon-carbon composites (Silicon-Carbon Composite 1) by CVI as follows.

[0136] 0.2 grams of amorphous porous carbon is placed in a 2" x 2" ceramic crucible and placed in the center of a horizontal tube furnace. The furnace is sealed and continuously purged with nitrogen gas at 500 cubic centimeters per minute (ccm). The furnace temperature is ramped at 20°C / min to a peak temperature of 450°C, where it is allowed to equilibrate for 30 minutes. At this point, the nitrogen gas is shut off and silane and hydrogen gas are introduced at rates of 50 ccm and 450 ccm, respectively, for a total residence time of 30 minutes. After the residence time is over, the silane and hydrogen are shut off and nitrogen is again introduced to purge the furnace atmosphere. The furnace is simultaneously turned off and cooled to ambient temperature. The finished Si-C material is then removed from the furnace. TIFF2024540577000003.tif38134

[0137] Example 2: Analysis of various silicon composite materials The specific surface area, total pore volume, and percentage of micropores, mesopores, and macropores in the pore volume of various carbon scaffold materials were measured by nitrogen adsorption gas analysis. The characterization data of the carbon scaffold materials, i.e., the surface area, pore volume, and pore volume distribution (% microporosity, % mesoporosity, and % macroporosity) of the carbon scaffold materials, are shown in Table 3. TIFF2024540577000004.tif103134

[0138] The carbon scaffold samples listed in Table 4 are used to produce various silicon-carbon composites employing the CVI method in a static bed configuration as outlined in Example 1. The silicon-carbon samples are produced using process conditions of silane concentrations between 1.25% and 100%, diluent gases nitrogen or hydrogen, and carbon scaffold starting masses between 0.2 g and 700 g.

[0139] The surface area of ​​the silicon-carbon composite is measured. The silicon-carbon composite is also analyzed by TGA to determine the silicon content. The silicon-carbon composite is also tested in a half-cell coin cell. The anode of the half-cell coin cell may contain 60-90% silicon-carbon composite, 5-20% Na-CMC (as a binder), and 5-20% Super C45 (as a conductivity enhancer), and the electrolyte may contain 2:1 ethylene carbonate:diethylene carbonate, 1M LiPF6, and 10% fluoroethylene carbonate. The half-cell coin cell may be cycled at 25°C at a C / 5 rate for 5 cycles, followed by a C / 10 rate. The voltage may be cycled between 0V and 0.8V, or alternatively between 0V and 1.5V. From the half-cell-coin cell data, the maximum capacity and the average Coulombic efficiency (CE) from cycle 7 to cycle 20 may be measured. The physicochemical and electrochemical properties of various silicon-carbon composites are shown in Table 4. TIFF2024540577000005.tif165129

[0140] Example 3: Particle size distribution of various carbon scaffold materials The particle size distribution of various carbon scaffold materials is determined using a laser diffraction particle size analyzer as known in the art. Table 5 shows the particle size distribution data, specifically, Dv1, Dv10, Dv50, Dv90, and Dv100. TIFF2024540577000006.tif74140

[0141] Example 4: Blends of various silicon-carbon composite materials In this example, two silicon-carbon composites are blended in various ratios. The first material, designated silicon-carbon composite 22, has a particle size distribution including Dv1, Dv10, Dv50, Dv90, and Dv99, or 0.35 μm, 0.76 μm, 3.28 μm, 6.30 μm, and 8.28 μm, respectively. The second material, designated silicon-carbon composite 23, has a particle size distribution including Dv1, Dv10, Dv50, Dv90, and Dv99, or 4.23 μm, 5.73 μm, 8.80 μm, 13.0 μm, and 15.98 μm, respectively. The particle size distributions of these two materials are shown in FIG. 1. These two materials were blended in various mass ratios, for example 30% silicon-carbon composite 22 and 70% silicon-carbon composite 23, alternatively 50% silicon-carbon composite 22 and 50% silicon-carbon composite 23, alternatively 70% silicon-carbon composite 22 and 30% silicon-carbon composite 23, and the corresponding particle size distributions are shown in FIG. 2.

[0142] Example 5: Multiple blended silicon-carbon composites In this Example 5, two silicon-carbon composites were blended in various ratios. The first material, shown in Table 5 as silicon-carbon composite 24, has a particle size distribution including Dv1, Dv10, Dv50, Dv90, and Dv99, or 0.6 μm, 1.0 μm, 2.3 μm, 5.3 μm, and 7.9 μm, respectively. The second material, shown in Table 6 as silicon-carbon composite 25, has a particle size distribution including Dv1, Dv10, Dv50, Dv90, and Dv99, or 1.2 μm, 4.1 μm, 8.2 μm, 14.6 μm, and 20.8 μm, respectively. The above materials 24 and 25 were blended in various mass ratios. For example, blend 1 includes 10% composite 24 and 90% composite 25. Blend 2 contains 90% composite 24 and 10% composite 25. Finally, Blend 3 contains 50% composite 24 and 50% composite 25. TIFF2024540577000007.tif60114

[0143] (Embodiment) (Embodiment 1) (a)(i) A pore volume of 0.5 cm3 or less that contains micropores and mesopores. 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% by weight to 90% by weight of a first silicon-carbon composite material and 10% by weight to 90% by weight of a second silicon-carbon composite material. 1. A silicon-carbon composite mixture comprising: (Embodiment 2) A silicon-carbon composite material mixture is 30 m 2 2. The silicon-carbon composite blend of embodiment 1 having a surface area of ​​less than 1.0 μm / g. (Embodiment 3) E is greater than 0.01, where E is 1-(density of composite mixture) / (mass average density of individual fractions) 3. The silicon-carbon composite blend of embodiment 1 or 2, wherein the density is defined as the electrode density measured in an electrode composed of 70 wt.% composite, 20 wt.% graphite, 2 wt.% Super C65, and 8 wt.% PAA. (Embodiment 4) The silicon-carbon composite mixture of embodiment 3, wherein the electrode properties of the silicon-carbon composite mixture and individual fractions comprising each mode are measured under otherwise identical conditions to determine E. (Embodiment 5) (a)(i) A pore volume of at least 0.5 cm3 containing micropores and mesopores. 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% to 90% by weight of a first silicon-carbon composite material and 10% to 90% by weight of a second silicon-carbon composite material; (d) 30m 2 / g surface area, and (e) E greater than 0.01 [where E is 1-(tap density of composite mixture) / (mass average tap density of individual fractions) is defined as: Including, (f) A silicon-carbon composite mixture, measuring the tap density of the mixture and measuring the tap density of each individual fraction containing each mode under otherwise identical conditions to determine E. (Embodiment 6) (a)(i) A pore volume of at least 0.5 cm3 containing micropores and mesopores. 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% to 90% by weight of a first silicon-carbon composite material and 10% to 90% by weight of a second silicon-carbon composite material; (d) 30m 2 / g surface area, and (e) E greater than 0.01 [where E is 1-(Conductivity of composite mixture) / (Mass average conductivity of individual fractions) is defined as: 1. A silicon-carbon composite mixture comprising: (Embodiment 7) The silicon-carbon composite blend of any one of embodiments 1 to 6, wherein E is greater than 0.05. (Embodiment 8) The silicon-carbon composite blend of any one of embodiments 1 to 6, wherein E is greater than 0.1. (Embodiment 9) (a) providing a porous carbon scaffold; (b) Milling the porous carbon scaffold; (i) a first porous carbon composite material including a plurality of particles having a Dv50 of 6 μm to 20 μm; (ii) a second porous carbon composite material having a particle size distribution of Dv50=1 μm to 6 μm; generating at least two fine particle fractions comprising: (c) impregnating the pores of at least two particulate fractions of the porous carbon composite with silicon by chemical vapor infiltration to produce a first silicon-carbon composite and a second silicon-carbon composite; and (d) blending the first silicon-carbon composite material and the second silicon-carbon composite material. A method for producing a silicon-carbon composite blend comprising: (Embodiment 10) The silicon-carbon composite mixture of any one of embodiments 1 to 9, wherein the mixture comprises a first fraction of the first silicon-carbon composite material in a proportion of 60% to 90% by weight and a second silicon-carbon composite material in a proportion of 10% to 40% by weight. (Embodiment 11) The silicon-carbon composite mixture of any one of embodiments 1 to 10, wherein the mixture comprises a first fraction of a first silicon-carbon composite material in a proportion of 70% to 90% by weight and a second silicon-carbon composite material in a proportion of 10% to 30% by weight. (Embodiment 12) (a) providing a porous carbon scaffold; (b) Milling the porous carbon scaffold; (i) a first porous carbon composite material including a plurality of particles having a Dv50 of 6 μm to 20 μm; (ii) a second porous carbon composite material having a particle size distribution of Dv50=1 μm to 6 μm; generating at least two fine particle fractions comprising: (c) impregnating the pores of at least two particulate fractions of the porous carbon composite with silicon by chemical vapor infiltration; (d) applying a coating to the surface of at least two particulate fractions of the porous silicon-carbon composite material by chemical vapor deposition; and (e) blending the first particulate silicon-carbon composite material and the second particulate silicon-carbon composite material. A method for producing a silicon-carbon composite blend comprising: (Embodiment 13) (a)(i) A pore system comprising micropores and mesopores, the total pore volume of which is less than or equal to 0.5 cm 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% by weight to 90% by weight of a first silicon-carbon composite material and 10% by weight to 90% by weight of a second silicon-carbon composite material. A silicon-carbon composite mixture comprising: an anode electrode. (Embodiment 14) The silicon-carbon composite mixture has a surface area of ​​30 m 2 14. The anode electrode of embodiment 13, wherein the anode electrode has a viscosity of less than 1000 saturation / g. (Embodiment 15) An anode electrode has a density with E greater than 0.01, where E is 1-(density of composite mixture) / (mass average density of individual fractions) 15. The anode electrode of embodiment 13 or 14, wherein the density is defined as the electrode density measured in an electrode composed of 70 wt.% composite, 20 wt.% graphite, 2 wt.% Super C65, and 8 wt.% PAA. (Embodiment 16) The anode electrode of embodiment 15, wherein the electrode properties of the silicon-carbon composite mixture and individual fractions comprising each mode are measured under otherwise identical conditions to determine E. (Embodiment 17) An anode electrode has a density E greater than 0.01, where E is 1-(tap density of composite mixture) / (mass average tap density of individual fractions) 15. The anode electrode of embodiment 13 or 14, wherein the density is defined as the electrode density measured in an electrode composed of 70 wt.% composite, 20 wt.% graphite, 2 wt.% Super C65, and 8 wt.% PAA. (Embodiment 18) The anode electrode of embodiment 17, wherein the electrode properties of the silicon-carbon composite mixture and individual fractions comprising each mode are measured under otherwise identical conditions to determine E. (Embodiment 19) The anode electrode according to any one of embodiments 15 to 18, wherein E is greater than 0.05. (Embodiment 20) The anode electrode according to any one of embodiments 15 to 18, wherein E is greater than 0.1. Embodiment 21. The anode electrode of any one of embodiments 13 to 20, wherein the silicon-carbon composite mixture comprises at least one additional carbon and / or at least one binder. Embodiment 22. The anode electrode of embodiment 21, wherein the at least one additional carbon and / or the at least one binder is dissolved in the aqueous medium. 23. The silicon-carbon composite mixture according to claim 22, wherein the silicon-carbon composite mixture has a density of 1.05 g / cm 3 ~1.5g / cm 3 , or 1.1 g / cm 3 ~1.3g / cm 3 23. The anode electrode according to any one of embodiments 13 to 22, configured to have an electron density in the range of (Embodiment 24) The anode electrode of any one of embodiments 13 to 23, wherein the silicon-carbon composite mixture has an electrical conductivity in the range of 0.3 S / cm to 2 S / cm, or 0.5 S / cm to 1.2 S / cm. Embodiment 25. The anode electrode according to any one of embodiments 13 to 24, wherein the carbon is a hard carbon material, graphitic carbon, or a metal oxide. (Embodiment 26) An anode electrode described in any one of embodiments 13 to 25, wherein the at least one binder is configured to bond the porous carbon and a first silicon-carbon composite having the silicon content, the porous carbon and a silicon-carbon portion of the second silicon-carbon composite, and / or the first silicon-carbon composite and the second silicon-carbon composite. Embodiment 27. The anode electrode of any one of embodiments 13 to 26, wherein the silicon-carbon composite mixture comprises at least one additional binder. (Embodiment 28) The anode electrode of any one of embodiments 21, 22, 26, or 27, wherein the at least one binder or additional binder is a styrene butadiene gum / carboxymethyl cellulose (CMC / SBR) mixture, polyacrylic acid (PAA) and / or lithium polyacrylate (LiPAA) or sodium polyacrylate (NaPAA). 29. (a) mixing a silicon-carbon composite material with at least one carbon to form a mixture; (b) mixing the mixture and a binder solution in a twin screw extruder to form an electrode paste; (c) applying the electrode paste to a conductor to form at least one electrode; (d) drying the at least one electrode at a temperature between 100° C. and 140° C. A method for producing the anode electrode according to any one of embodiments 13 to 28, comprising: (Embodiment 30) (a) at least one anode electrode according to any one of embodiments 13 to 28; (b) at least one electrode configured as a cathode, the electrode comprising a transition metal oxide; (c) a separator disposed between the cathode and the anode; and (d) An electrolyte containing lithium ions Electrochemical storage device, in particular formed as a lithium-ion battery. (Embodiment 31) A silicon-carbon composite material comprising: (a)(i) A micropore and a mesopore having a total pore volume of 0.5 cm 3 / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 6 μm and 20 μm a first silicon-carbon composite material comprising: (b)(i) A total pore volume of 0.5 cm3, including micropores and mesopores 3 / g or more; (ii) a silicon content of 30% to 70%; (iii) Multiple particles with Dv50 between 1 μm and 6 μm a second silicon-carbon composite material comprising: (c) 10% by weight to 90% by weight of a first silicon-carbon composite material and 10% by weight to 90% by weight of a second silicon-carbon composite material. Use of a silicon-carbon composite blend in an anode electrode, comprising: (Embodiment 32) A silicon-carbon composite material having a surface area of ​​30 m 2 The use according to embodiment 31, wherein the .lambda. / g is less than 100 / g. (Embodiment 33) An anode electrode has a density with E greater than 0.01, where E is 1-(density of composite mixture) / (mass average density of individual fractions) 33. The use of embodiment 31 or 32, wherein the density is defined as the electrode density measured in an electrode composed of 70 wt.% composite, 20 wt.% graphite, 2 wt.% Super C65, and 8 wt.% PAA. (Embodiment 34) The use according to embodiment 33, wherein the determination of E of the silicon-carbon composite mixture and the individual fractions comprising each mode is measured under otherwise identical conditions. (Embodiment 35) The use according to embodiment 33 or 34, wherein E is greater than 0.05. (Embodiment 36) The use according to embodiment 33 or 34, wherein E is greater than 0.1. (Embodiment 37) Use of the anode electrode according to any one of embodiments 13 to 28 in an electrochemical storage device. (Embodiment 38) (a) providing a current collector comprising copper; (b) (i) a silicon-carbon composite anode active material comprising a plurality of particles having a Dv50 of 1 μm to 6 μm; (ii) a binder, and (iii) A conductive carbon material including a plurality of particles having a Dv50 of 1 nm to 1 μm. applying to a current collector a first anode composition comprising: (c) (i) a silicon-carbon composite anode active material comprising a plurality of particles having a Dv50 of 1 μm to 20 μm; (ii) a binder, and (iii) A conductive carbon material including a plurality of particles having a Dv50 of 1 nm to 1 μm. applying a second anode composition over the first anode composition comprising Including, (d) the ratio of the Dv50 of the silicon-carbon composite material in the first anode composition to the Dv50 of the silicon-carbon composite material in the second anode composition is greater than 1; (e) A method of making an anode electrode, wherein the ratio of a silicon content of the silicon-carbon composite material in the first anode composition to a silicon content of the silicon-carbon composite material in the second anode composition is less than 1. Embodiment 39. The first silicon-carbon composite anode active material comprises micropores and mesopores and has a total pore volume of 0.5 cm 3 39. A method of making an electrode as described in embodiment 38, comprising: a carbon scaffold having a surface area of ​​0.1 μm or more; and a plurality of particles having a silicon content of 30% to 70% and a Dv50 of 1 μm to 6 μm. Embodiment 40. A second silicon-carbon composite anode active material having micropores and mesopores and a total pore volume of 0.5 cm 3 39. A method of making an electrode as described in embodiment 38, comprising: a carbon scaffold having a Dv50 of 30% to 70% and a Dv50 of 6 μm to 20 μm, the carbon scaffold having a Dv50 of 30% to 70% and a Dv50 of 6 μm to 20 μm. (Embodiment 41) (a) A first silicon-carbon composite anode active material having micropores and mesopores and a total pore volume of 0.5 cm 3 / g or more, a plurality of particles having a silicon content of 30% to 70% and a Dv50 of less than 6 μm; (b) a second silicon-carbon composite anode active material having micropores and mesopores and a total pore volume of 0.5 cm 3 39. A method of making an electrode as described in embodiment 38, comprising: a carbon scaffold having a silicon content of 30% to 70% and a plurality of particles having a Dv50 greater than 6 μm; Embodiment 42. A method of making an electrode according to any one of embodiments 38-42, wherein the first silicon-carbon composite anode active material comprises graphite. Embodiment 43. A method of making an electrode according to any one of embodiments 38-42, wherein the second silicon-carbon composite anode active material comprises graphite. Embodiment 44. A method of making an electrode as described in any one of embodiments 38-42, wherein the first silicon-carbon composite anode active material comprises graphite and the second silicon-carbon composite anode active material comprises graphite. Embodiment 45. A method of making an electrode according to any one of embodiments 38 to 44, wherein the second silicon-carbon composite anode active material has a silicon content less than the silicon content of the first silicon-carbon composite anode active material. Embodiment 46. A method of making an electrode according to any one of embodiments 38 to 44, wherein the second silicon-carbon composite anode active material has a silicon content greater than the silicon content of the first silicon-carbon composite anode active material. (Embodiment 47) An electrode produced from any one of embodiments 38-46.

Claims

1. (a) (i) a porous membrane containing micropores and mesopores, the total pore volume of which is 0.5 cm ３ / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) a plurality of particles having a Dv50 of 6 μm to 20 μm a first silicon-carbon composite material comprising: (b) (i) a porous membrane containing micropores and mesopores, the total pore volume of which is 0.5 cm ３ / g or greater; (ii) a silicon content of 30% to 70%; (iii) a plurality of particles having a Dv50 of 1 μm to 6 μm a second silicon-carbon composite material comprising: (c) 10% to 90% by weight of a first silicon-carbon composite material and 10% to 90% by weight of a second silicon-carbon composite material.

1. A silicon-carbon composite blend comprising:

2. 10. The silicon-carbon composite blend of claim 1, wherein the blend further comprises one or more additional silicon-carbon composite materials, each of the one or more additional silicon-carbon composite materials having a unique Dv50.

3. The silicon-carbon composite mixture is 30 m ２ 10. The silicon-carbon composite blend of claim 1 having a surface area of ​​less than 1000 W / g.

4. E is greater than 0.01, where E is 1 - (density of composite mixture) / (mass average density of individual fractions) 4. The silicon-carbon composite blend of claim 1, 2 or 3, wherein the density is defined as an electrode density measured in an electrode composed of 70 wt. % composite, 20 wt. % graphite, 2 wt. % Super C65, and 8 wt. % PAA.

5. 5. The silicon-carbon composite blend of claim 4, wherein measurements of the electrode properties of the silicon-carbon composite blend and individual fractions comprising each mode are measured under otherwise identical conditions to determine E.

6. (a) (i) a porous membrane containing micropores and mesopores, the total pore volume of which is 0.5 cm ３ / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) a plurality of particles having a Dv50 of 6 μm to 20 μm a first silicon-carbon composite material comprising: (b) (i) a porous membrane containing micropores and mesopores, the total pore volume of which is 0.5 cm ３ / g or greater; (ii) a silicon content of 30% to 70%; (iii) a plurality of particles having a Dv50 of 1 μm to 6 μm a second silicon-carbon composite material comprising: (c) 10% to 90% by weight of a first silicon-carbon composite material and 10% to 90% by weight of a second silicon-carbon composite material; (d) 30 m ２ / g, and (e) E greater than 0.01, where E is 1 - (tap density of composite mixture) / (mass average tap density of individual fractions) is defined as: Including, (f) A silicon-carbon composite mixture, measuring the tap density of the silicon-carbon composite mixture and measuring the tap density of the individual fractions comprising each mode under otherwise identical conditions to determine E.

7. (a) (i) a porous membrane containing micropores and mesopores, the total pore volume of which is 0.5 cm ３ / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) a plurality of particles having a Dv50 of 6 μm to 20 μm a first silicon-carbon composite material comprising: (b) (i) a porous membrane containing micropores and mesopores, the total pore volume of which is 0.5 cm ３ / g or greater; (ii) a silicon content of 30% to 70%; (iii) a plurality of particles having a Dv50 of 1 μm to 6 μm a second silicon-carbon composite material comprising: (c) 10% to 90% by weight of a first silicon-carbon composite material and 10% to 90% by weight of a second silicon-carbon composite material; (d) 30 m ２ / g, and (e) E greater than 0.01, where E is 1 - (Conductivity of composite mixture) / (Mass average conductivity of individual fractions) is defined as:

1. A silicon-carbon composite blend comprising:

8. 2. The silicon-carbon composite blend of claim 1, wherein E is greater than 0.

05.

9. 2. The silicon-carbon composite blend of claim 1, wherein E is greater than 0.

1.

10. (a) providing a porous carbon scaffold; (b) crushing the porous carbon scaffold; (i) a first porous carbon composite material comprising a plurality of particles having a Dv50 of 6 μm to 20 μm; (ii) A second porous carbon composite material having a particle size distribution of Dv50 = 1 μm to 6 μm generating at least two fine particle fractions comprising: (c) impregnating the pores of at least two particulate fractions of the porous carbon composite with silicon by chemical vapor infiltration to produce a first silicon-carbon composite and a second silicon-carbon composite; and (d) blending the first silicon-carbon composite material and the second silicon-carbon composite material.

1. A method for producing a silicon-carbon composite blend, comprising:

11. 10. The silicon-carbon composite blend of claim 1, wherein the blend comprises a first fraction of the first silicon-carbon composite in a proportion of 60% to 90% by weight and a second fraction of the second silicon-carbon composite in a proportion of 10% to 40% by weight.

12. 10. The silicon-carbon composite blend of claim 1, wherein the blend comprises a first fraction of the first silicon-carbon composite in a proportion of 70% to 90% by weight and a second fraction of the second silicon-carbon composite in a proportion of 10% to 30% by weight.

13. (a) providing a porous carbon scaffold; (b) crushing the porous carbon scaffold; (i) a first porous carbon composite material comprising a plurality of particles having a Dv50 of 6 μm to 20 μm; (ii) A second porous carbon composite material having a particle size distribution of Dv50 = 1 μm to 6 μm generating at least two fine particle fractions comprising: (c) impregnating the pores of at least two particulate fractions of the porous carbon composite with silicon by chemical vapor infiltration; (d) applying a coating to the surface of at least two particulate fractions of the porous silicon-carbon composite material by chemical vapor deposition; and (e) blending the first particulate silicon-carbon composite material and the second particulate silicon-carbon composite material.

1. A method for producing a silicon-carbon composite blend, comprising:

14. (a) (i) a porous membrane containing micropores and mesopores, the total pore volume of which is 0.5 cm ３ / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) a plurality of particles having a Dv50 of 6 μm to 20 μm a first silicon-carbon composite material comprising: (b) (i) a porous membrane containing micropores and mesopores, the total pore volume of which is 0.5 cm ３ / g or greater; (ii) a silicon content of 30% to 70%; (iii) a plurality of particles having a Dv50 of 1 μm to 6 μm a second silicon-carbon composite material comprising: (c) 10% to 90% by weight of a first silicon-carbon composite material and 10% to 90% by weight of a second silicon-carbon composite material. Silicon-carbon composite blends comprising: an anode electrode.

15. The surface area of ​​the silicon-carbon composite material mixture is 30 m ２ 15. The anode electrode according to claim 14, wherein the anode electrode has a Mo+ / g or less.

16. The anode electrode has a density with E greater than 0.01, where E is 1 - (density of composite mixture) / (mass average density of individual fractions) 15. The anode electrode of claim 14, wherein the density is defined as:

17. 17. The anode electrode of claim 16, wherein measurements of the electrode properties of the silicon-carbon composite mixture and individual fractions comprising each mode are measured under otherwise identical conditions to determine E.

18. The anode electrode has a density with E greater than 0.01, where E is 1 - (tap density of composite mixture) / (mass average tap density of individual fractions) 15. The anode electrode of claim 14, wherein the density is defined as:

19. 20. The anode electrode of claim 18, wherein measurements of the electrode properties of the silicon-carbon composite mixture and individual fractions comprising each mode are measured under otherwise identical conditions to determine E.

20. 17. The anode electrode of claim 16, wherein E is greater than 0.

05.

21. 17. The anode electrode of claim 16, wherein E is greater than 0.

1.

22. 15. The anode electrode of claim 14, wherein the silicon-carbon composite mixture comprises at least one additional carbon and / or at least one binder.

23. 23. The anode electrode of claim 22, wherein the at least one further carbon and / or the at least one binder is dissolved in an aqueous medium.

24. The silicon-carbon composite mixture has a density of 1.05 g / cm ３ ~1.5g / cm ３ , or 1.1 g / cm ３ ~1.3g / cm ３ 15. The anode electrode of claim 14 configured to have an electron density in the range of

25. 25. The anode electrode according to any one of claims 14 to 24, wherein the silicon-carbon composite mixture has an electrical conductivity in the range of 0.3 S / cm to 2 S / cm, or 0.5 S / cm to 1.2 S / cm.

26. 15. The anode electrode according to claim 14, wherein the carbon is a hard carbon material, graphitic carbon, or a metal oxide.

27. 15. The anode electrode of claim 14, wherein the at least one binder is configured to bond the porous carbon and the silicon-containing first silicon-carbon composite, the porous carbon and the silicon-carbon portion of the second silicon-carbon composite, and / or the first silicon-carbon composite and the second silicon-carbon composite.

28. 15. The anode electrode of claim 14, wherein the silicon-carbon composite mixture comprises at least one additional binder.

29. 23. The anode electrode of claim 22, wherein the at least one binder or additional binder is a styrene butadiene gum / carboxymethyl cellulose (CMC / SBR) mixture, polyacrylic acid (PAA) and / or lithium polyacrylate (LiPAA) or sodium polyacrylate (NaPAA).

30. (a) mixing the silicon-carbon composite mixture with at least one carbon to form a mixture; (b) mixing the mixture and the binder solution in a twin-screw extruder to form an electrode paste; (c) applying the electrode paste to the conductor to form at least one electrode; (d) drying the at least one electrode at a temperature between 100°C and 140°C The method for manufacturing the anode electrode of claim 14 , comprising:

31. (a) at least one anode electrode according to claim 14; (b) at least one electrode configured as a cathode, comprising a transition metal oxide; (c) a separator disposed between the cathode and the anode; and (d) an electrolyte containing lithium ions Electrochemical storage device, in particular formed as a lithium ion battery, comprising:

32. Silicon-carbon composite materials, (a) (i) a porous membrane containing micropores and mesopores, the total pore volume of which is 0.5 cm ３ / g or more of a porous carbon scaffold; (ii) a silicon content of 30% to 70%; (iii) a plurality of particles having a Dv50 of 6 μm to 20 μm a first silicon-carbon composite material comprising: (b) (i) a porous membrane containing micropores and mesopores, the total pore volume of which is 0.5 cm ３ / g or greater; (ii) a silicon content of 30% to 70%; (iii) a plurality of particles having a Dv50 of 1 μm to 6 μm a second silicon-carbon composite material comprising: (c) 10% to 90% by weight of a first silicon-carbon composite material and 10% to 90% by weight of a second silicon-carbon composite material. Use of a silicon-carbon composite blend in an anode electrode, comprising:

33. The surface area of ​​the silicon-carbon composite material is 30 m ２ 33. The use according to claim 32, wherein the hydroxyl group is less than 1 / g.

34. The anode electrode has a density with E greater than 0.01, where E is 1 - (density of composite mixture) / (mass average density of individual fractions) 33. The use of claim 32, wherein the density is defined as: wherein the density is the electrode density measured in an electrode composed of 70 wt% composite, 20 wt% graphite, 2 wt% Super C65, and 8% PAA.

35. 35. The use of claim 34, wherein the determination of E of the silicon-carbon composite mixture and the individual fractions comprising each mode is measured under otherwise identical conditions.

36. 35. The use according to claim 34, wherein E is greater than 0.

05.

37. 35. The use according to claim 34, wherein E is greater than 0.

1.

38. Use of the anode electrode according to claim 14 in an electrochemical storage device.

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