Carbon nanostructures for dry processed battery electrodes

Abstract

A solvent-free process employs carbon nanostructures to prepare compositions and electrodes for lithium-ion batteries. The carbon nanostructures can be multifunctional, providing two or more desirable characteristics, acting, for example, as a conductive carbon additive, as a fibrillizing agent and / or as a mechanical reinforcement. In one example, an electroactive material, a binder, e.g., PTFE, and carbon nanostructures are combined in one or more steps. High shear mixing is used to process the binder in the presence of the carbon nanostructures. In some implementations, the carbon nanostructures are provided in combination with a carbon black and / or with carbon nanotubes. Some anode compositions can be prepared by processing the binder in the presence of a composite that contains the carbon nanostructures and an active anode material. Generally, the binder is processed in the absence of solvent. The resulting composition can be formed into a film which can be applied onto a suitable substrate to form an electrode.

Description

Docket: 2020617PCTTITLECarbon Nanostructures for Dry Processed Battery ElectrodesCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit under 35 USC 119 of U. S. Provisional Application No. 63 / 737,930 filed on December 23, 2024, the disclosure of which is hereby incorporated herein by reference in its entirety.BACKGROUND

[0002] Lithium-ion batteries (LIBs) are commonly used sources of electrical energy for numerous applications ranging from electronic devices to electric vehicles. A lithium-ion battery typically includes a negative electrode and a positive electrode in an arrangement that allows lithium ions and electrons to move to and from the electrodes during charging and discharging. An electrolyte solution in contact with the electrodes provides a conductive medium in which the ions can move. To prevent direct reaction between the electrodes, an ion-permeable separator is used to physically and electrically isolate the electrodes. During operation, electrical contact is made to the electrodes, allowing electrons to flow through the device to provide electrical power, and lithium ions to move through the electrolyte from one electrode to the other.

[0003] Most commercially available lithium-ion batteries have anodes that contain graphite, a material capable of incorporating lithium through an intercalation mechanism. Typically, lithium is added to the graphite anode during the charging cycle and removed as the battery is used. Other anode materials used in addition to or alternatively to graphite include lithium titanate, tin oxide, silicon (Si) and SiOx (with x typically being 1.04, 1.06, etc.). In illustrative examples the anode includes graphite, silicon suboxide (SiOx, x<2), silicon-carbon composite, and / or silicon-containing compound.

[0004] Cathodes typically include a conductive substrate supporting a mixture containing at least an electrochemically active material and a binder. The electroactive material, such as aDocket: 2020617PCTlithium transition metal oxide, is capable of receiving and releasing lithium ions. As with the anode, the binder is used to provide mechanical integrity and stability to the electrode.

[0005] Since the electroactive material and the binder often display poor electrically conducting or even insulating properties, cathodes often include an additive component which enhances the electrical conductivity of the electrode. Conductive additives, carbon conductive additives (CCA), for instance, also can be found in LIB anode compositions.

[0006] To manufacture the electrode, the active electrode material, graphite for instance, is mixed with a binder, typically a polymeric or resin material. Many existing fabrication methods employ casting techniques based on wet slurries that contain not only the binder but also solvents, plasticizers, conductive additives, and so forth. During manufacturing, the slurry is coated or extruded onto a conductive substrate. Since the solvent is detrimental to the final product, it is removed by drying.

[0007] However, drying operations, m particular those aimed at solvent removal, require time, slowing down the overall production process. Also, they can raise costs as well as environmental concerns, typically due to toxicity of the solvent, e.g., N-methyl-2-pyrrolidone (NMP). In terms of the end product, the removal of the solvent during the drying process often leads to migration of the binder to the surface of the electrode. Though minimal migration can be acceptable in some cases, it is problematic in others. For high loadings (thick, > 4.5 mAh / cm2) electrodes, for instance, the migration is exacerbated, leading to delamination and poor electrode performance.

[0008] As a result, “dry” alternatives, aiming at reducing or eliminating the diying step associated with slurry techniques, are being developed. While dry processes also produce electrodes that typically contain an electroactive material, binder and a conductive additive component, they do not require using a solvent.

[0009] Dry approaches that have been proposed include high shear mixing involving a fibrillizable binder, use of a sacrificial binder to be removed upon processing of the electrode, dry powder spraying, electrostatic spray deposition, cold plasma deposition, sputtering deposition, powder printing, to name a few. In some, a fibrillization promoter is incorporated into the binder and the resulting formulation is subjected to high shear mixing to fibrillate theDocket: 2020617PCTbinder, thereby generating a web-like structure that can better hold the materials together and support the active material.

[0010] To date, the most common additive used to promote binder fibrillization has been activated carbon (AC). Generally, AC is derived from carbonaceous source materials such as bamboo, coconut husk, willow peat, wood, coir, lignite, coal, and petroleum pitch. Activation is achieved by physical or chemical approaches, as known in the art. For many applications, AC powders are milled to tens of micron (micrometers; pm) particle dimensions prior to activation.SUMMARY

[0011] While dry manufacturing processes have the potential of eliminating many of the challenges posed by the addition and / or removal of solvents (often harmful), problems remain.

[0012] For example, current “dry” fabrication techniques utilize not only the active electrode material but many other ingredients such as fibrillization promoters, conductive additives and binders. Since many of these components are not involved in the electrochemical reactions that generate electrical energy, they can negatively affect certain performance characteristics (e.g., capacity and energy density) of the battery', as they effectively lower the amount of active material that can be contained in the available volume.

[0013] State of the art fibrillization agents such as ACs are often characterized by high impurity levels. Also, high surface areas and surface oxygen-containing groups typical for ACs tend to promote significant water uptake. These features can contribute to irreversible capacity losses, diminishing battery performance. Furthermore, ACs fail to add sufficient conductivity, raising the need for increased amounts of conductive additives in the overall formulation. Even as a simple fibrillization promoter, AC often requires relatively high loadings (5 to 10 weight %, in many cases) and this, in and of itself, also limits the amount of active materials that can be included.

[0014] It was discovered that AC can be supplemented and often entirely replaced by carbon nanotubes (CNTs), as described, for example, in International Patent Application No. PCT / US24 / 20620, filed on March 20, 2024, incorporated herein in its entirety by this reference.Docket: 2020617PCT

[0015] One problem faced during the solvent-free mixing of CNTs with other ingredients, however, relates to the potential release of airborne particulates, posing health and safety concerns. With a total weight average (TWA) exposure limit of 1 micrograms per cubic meter (μg / m3) of particulates in 8 hours, emissions of CNTs-derived particulates can become problematic for industrial-scale manufacturing.

[0016] Another challenge is the limited dispersibility of CNTs. For the conventional “wet” fabrication process of LiB electrodes, the CNTs are often pre-dispersed by means of high shear or used in formulated dispersions wherein the state of the CNTs (in the dispersant) is controlled. As such, the CNT dispersion state and adequate distribution throughout the electrode are often ensured by the flexibility of the “wet” process. On the other hand, the dry process often relies on dispersing a conductive additive (e.g., CNT powder) in the electrode matrix in-situ or requires the use of other strategies, which may severely impact the state of the conductive additive in the dry electrode and ultimately its performance.

[0017] In some cases, e.g., in silicon-based anodes for instance, multiwall CNTs were found to provide insufficient reinforcing support to maintain robust electrical networks throughout the electrode and minimize irreversible capacity loss related to structural changes and anomalously large volume expansions of electroactive material (e.g., Si) upon long-term charge / discharge cycling. Even as a conductive additive, multiwall CNTs may be required in relatively high loadings (for example, 1 weight % of Si-containing anode) and this, in and of itself, also limits the amount of active materials that can be included.

[0018] A need exists, therefore, for compositions and processes that address at least some of the problems associated with existing approaches.

[0019] This disclosure relates to the use of carbon nanostructures (CNSs) to bring about needed improvements in the compositions and fabrication methods for preparing product electrodes and / or assembled batteries. More specifically, it relates to the use of CNSs in the context of dry or solvent-free electrode manufacturing processes.

[0020] CNSs include a plurality' of multiwall carbon nanotubes that are crosslinked in a polymeric structure by being branched, interdigitated, entangled and / or sharing common walls. In specific embodiments, the carbon nanostructures employed have a multifunctional character,Docket: 2020617PCTproviding two or more desirable features. For example, the carbon nanostructures can act as a fibrillizing agent, serving as an AC substitute; as conductive carbon additive (by forming electrically conductive networks); and / or as a mechanical reinforcement, acting as a binding aid to add mechanical strength and flexibility to a product electrode. In the case of silicon-contaming anodes, CNSs can further act as a mechanical reinforcement of particles by encapsulating electroactive material (e.g., Si) and maintaining electrode integrity upon the volume expansion of Si during cycling.

[0021] Some approaches employ CNSs that are further processed to enhance at least one of the multifunctional attributes discussed above.

[0022] CNSs can be provided as made, in the form of a loose particulate material, e.g., CNS flakes, often unpurified and without a binder, as polymer coated CNSs, as polymer-coated pellets, as purified (e.g., acid-washed) CNSs or CNS pellets, as milled CNSs, or in other suitable forms. In some cases, the CNSs are provided in composites such as, for example, CNS-polymer composites or CNS-active anode material composites. Generally, the CNSs are free of the growth substrate typically employed in their manufacture. In some implementations, CNSs are provided in combination with another material such as, for example, carbon blacks (CBs), or carbon nanotubes (CNTs). In some embodiments CNSs are provided together with both a CB and a CNT component.

[0023] Preparing the compositions and / or articles described herein also involves an active electrode (anode or cathode) material and a binder. In some illustrative examples, the active anode material is or includes graphite, silicon (Si), SiOx, a graphite-Si composite, a silicon-carbon (Si / C) composite, lithium titanate or any combination thereof. In other illustrative examples, the active cathode material is a lithium transition metal compound.

[0024] The binder can be any semi-crystalline polymer. Accordingly, the method can be conducted with binders conventionally considered “fibnllizable” as well as with those conventionally thought of as “non-fibrillizable” binders; combinations thereof also can be utilized. As used herein, “processing” a binder refers to an operation conducted under shear conditions. In embodiments, the shear conditions are selected to fibrillate a fibrillizable binder or deform, elongate, entangle, etc. a non-fibrillizable binder. For convenience, the termDocket: 2020617PCT“fibrillating” or “fibrillizing” a binder is used herein to describe binder transformations (deformations, elongations, stretching, entanglements, the formation of ribbons, strands, etc.) occurring under suitable shear conditions with fibrillizable as well as non-fibrillizable binders.

[0025] In many embodiments, the method described herein employs ingredients that are provided as loose particulate materials such as flowing or pourable dry powders, flakes, beads, granules, pellets and so forth. The ingredients can be combined in one step or in any desired sequence. In one example, loose particulate CNSs (e.g., dry flakes) are combined with an active material in dry powder form and then with a binder, also provided as a loose particulate material.

[0026] Thus, one aspect of the disclosure features a method for preparing an electrode composition. In one approach, the method includes combining an active electrode material, a binder and carbon nanostructures, and processing the binder in the presence of the carbon nanostructures. In another approach, the method comprises processing a binder (subjecting the binder to high shear conditions, for example) in the presence of carbon nanostructures, and adding an electrode active material before, during or after binder processing. For preparing an anode composition, the binder can be processed, e.g., fibrillized in the presence of a composite that includes CNSs and an anode active material.

[0027] Typically, the binder is processed without adding a liquid, generally referred to herein as a “solvent”. In some cases, the entire method is conducted in the absence of solvent.

[0028] While many embodiments described herein are conducted under dry or solvent-free conditions, using ingredients in loose particulate form, the method for preparing an electrode composition can involve a solvent, e.g., to moisten or disperse powder particles in an operation other than the binder processing operation. In some implementations, the method further includes a solvent removal operation resulting in a dry precursor component that can be used in a subsequent dry or solvent-free binder processing.

[0029] For many fabrication protocols, solvent amounts are no greater than 10 wt % based on the total weight of all the ingredients. In specific cases, solvent is added in an amount that is no greater and often less than 1 wt %.

[0030] In an illustrative example, CNSs are provided in a dispersing solvent. The dispersion can be used to coat the anode active particles, a Si- containing active material, for example. ThisDocket: 2020617PCToperation is followed by a solvent removing step (e.g., using spray drying). The resulting dry intermediate precursor, e.g., a composite containing CNSs and the Si-containing active material in powder form, is then mixed with the binder, also provided as a dry powder. The binder is processed, e.g., fibnllized, in the absence of a solvent, to make the anode composition in loose particulate form.

[0031] Other approaches that involve a solvent during an intermediate step may be employed and may be followed by a drying step. In general, however, processing the binder in the presence of CNSs, or a component that includes CNSs is conducted under dry processing conditions, i.e., in the absence of solvent.

[0032] In specific embodiments, the method described herein is conducted without adding any fibrillating aid other than the carbon nanostructures. In such a case, the CNSs employed provide the entire binder processing (e.g., fibrillating) functionality, completely replacing conventional fibrillating agents such as activated carbons, for instance.

[0033] In addition to employing a binder processing (e.g., fibrillating) component that consists of carbon nanostructures, it is also possible to use a binder processing component that consists essentially of or that comprises carbon nanostructures. For instance, the CNSs can be used in combination with various amounts of a conventional fibrillizing aid, an activated carbon, for example. It is also possible to employ the CNSs in combination with a conventional conductive carbon additive (CCA). Typically, the CCA will lack fibrillizing properties.

[0034] Some embodiments of the disclosure employ CNSs in combination with at least one carbon black (CB). In some cases, the CB is multifunctional, playing at least two of the following roles: conductive additive, fibrillating aid, mechanical reinforcement. Further embodiments employ CNSs in combination with carbon nanotubes (CNTs) that are not part of or derived from CNSs (also referred to herein as “fresh”, “pristine”, or “ordinary'” CNTs), which too can be multifunctional. Compositions, techniques, films, electrodes, batteries, etc. that contain a combination of CNSs, CB and pristine CNTs also can be utilized. In some implementations, CNSs are combined with at least one other multifunctional constituent selected from the group consisting of a multifunctional CB and multifunctional CNTs.Docket: 2020617PCT

[0035] The electroactive (anode or cathode) material, the binder, e.g., a fibrillizable binder, and the carbon nanostructures can be combined in a single step, the binder processing, a fibrillization operation, for instance, being conducted subsequently. In a different approach, the constituents are combined sequentially. For example, the binder, in the presence of the carbon nanostructures, is processed, e.g., fibrillized, first, this step being followed by mixing with the electroactive material. Dry composite particles that include CNSs and an anode active material can be combined with the binder, followed by a binder processing step. Other sequences are possible.

[0036] Uniform distributions of constituents can be obtained using conditions other (often milder) than those utilized in the binder processing, e.g., fibrillization. Low shear mixing techniques also can prevent particle fragmentations and preserve particle size. Intermediate blends or composites formed using a solvent are dried prior to binder processing, e.g., fibrillization.

[0037] Other operations, e.g., sieving of one or more of the loose particulate materials involved in performing the method described herein, can be included.

[0038] The resulting electrode composition, typically a loose particulate material such as a flowing powder, containing electroactive material, a processed binder (a fibrillized binder in some cases), post-processing carbon nanostructures (a component that can include not only carbon nanostructures but also fragments of carbon nanostructures and / or fractured nanotubes) and, optionally, other ingredients (e.g., other CCAs, AC, CBs, CNTs, materials derived from the CNS pellets or composites that may have been employed in preparing the electrode composition, etc.) can be subjected to further operations. For example, the composition can be formed into a free-standing film that can be applied to an electrically conductive substrate or support to form an electrode. In one approach, the composition is calendered and laminated to a conductive foil substate. The calendering operation can be conducted at or above room temperature, e.g., at a temperature similar or close to the polymer glass transition temperature. The lamination step can be performed during or after the composition is calendered. The resulting product electrode can be assembled into a LIB battery in which one or both electrodes is / are prepared by a solvent-free process. In one example, both electrodes are prepared according to techniques described herein.Docket: 2020617PCT

[0039] In a further aspect, the disclosure features a film which includes an active electrode material, a binder and carbon nanostructures, fragments of carbon nanostructures and / or fractured nanotubes. Before any drying operation, the film can contain solvent residue in an amount no greater than about 10 wt % relative to the theoretical weight of the film electrode. Or, before any drying operation, the film has a weight that is the same as or within 10 wt % of its theoretical weight. For many applications, drying the film will result in a film having a weight that is within 1 wt % of its theoretical weight, or a film containing solvent in an amount not greater than I wt % relative to the theoretical weight of the film.

[0040] Some embodiments feature a dry processed film which, before any drying operation, contains solvent m an amount not greater than about 1 wt % relative to the theoretical weight of the film electrode. Or, before any drying operation, the dry processed film has a weight that is the same as or within 1 wt % of its theoretical weight.

[0041] An illustrative dry processed electrode includes an active material in an amount of from about 92 wt % to about 99.8 wt %, binder in an amount of from about 0.1 wt % to about 5 wt % and a CNS component in an amount of from about 0.1 wt % to about 3 wt %.

[0042] Practicing embodiments described herein has many advantages. Using CNSs, for example, can reduce the amount of binder and / or conventional processing additives required in the fabrication process, increasing the potential loading with active materials and leading to higher energy density electrodes and therefore batteries. Approaches described herein can reduce or eliminate the need for ACs. In many cases, smaller additive amounts are needed, increasing the available content allowed for active electrode materials, yielding batteries with higher energy densities and longer lifetimes.

[0043] The web-like structure of CNSs makes these materials good candidates for binder fibrillization and can promote mechanical reinforcement, improving the tensile strength and / or the elastic modulus of a free standing film, for example. The entangled characteristics and other structural features discussed above provide the electrical pathways desired for electrical connectivity and increase electrode cohesiveness.

[0044] The CNS additive can improve material distribution across the electrode. Enhanced adhesion and mechanical stability represent yet other potential benefits. Dry-processedDocket: 2020617PCTelectrodes prepared using carbon nanostructures exhibit good charge transfer. The reduction in electrode impedance expected with a CNS additive can improve cell rate capacity and charging performance, opening opportunities for thicker electrodes and higher energy density batteries with fast charging capabilities. With anode compositions that contain silicon or SiOx, some of the benefits associated with the use of CNSs may be due to improvements in electrical conductivity, connectivity and silicon swelling management.

[0045] In some cases, the CNSs generate fragments (including partially fragmented CNSs) and / or fractured CNTs, fractured multiwall CNT (MWCNTs), for example. These structures can bring about improved connectivity between one another, thereby enhancing electrical conductivity in the electrode.

[0046] Whereas binder migration phenomena are often observed with slurry-prepared electrodes (with increased binder concentration at the surface of the electrode), the process and composition described herein appear to yield uniform distributions across the electrode. This binder distribution can be observed by techniques such as energy dispersive spectroscopy (EDS).

[0047] Advantageously, by practicing aspects of the disclosure it is possible to obtain thicker films or electrodes than those generally obtained by wet techniques, where cracking issues often limit the electrode thickness to less than 100 microns.

[0048] The processed, e.g., fibrillated, binder keeps the electroactive particles (along with the conductive additives) together (cohesion), while also keeping the electrode film layer attached to the metal substrate (adhesion).

[0049] The solvent-free techniques described herein reduce or eliminate the use of harmful solvents such as NMP and the like. Being able to bypass the drying step associated with slurry (or other “wet” processes) can simplify, speed up manufacture and reduce the footprint of the electrode production line. These benefits, as well as reducing or eliminating the need for solvent recycling or emissions abatement measures can contribute to overall cost reductions.

[0050] The above and other features of the disclosure including various details of construction and combinations of parts, and other advantages, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It willDocket: 2020617PCTbe understood that the particular method and device embodying the disclosure are shown by way of illustration and not as a limitation of the disclosure. The principles and features of this disclosure may be employed in various and numerous embodiments without departing from the scope of the disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0051] In the accompanying drawings, reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale; emphasis has instead been placed upon illustrating the principles of the disclosure. Of the drawings:

[0052] FIGS. 1A and IB are diagrams illustrating differences between a Y-shaped MWCNT, not in or derived from a carbon nanostructure (FIG. 1A), and a branched MWCNT (FIG. 1B) in a carbon nanostructure.

[0053] FIGS. 2A and 2B are TEM images showing features characterizing multiwall carbon nanotubes found in carbon nanostructures.

[0054] FIGS. 2C and 2D are SEM images of carbon nanostructures showing the presence of multiple branches.

[0055] FIG. 3A is an illustrative depiction of a carbon nanostructure flake material after isolation of the carbon nanostructure from a growth substrate;

[0056] FIG. 3B is a SEM image of an illustrative carbon nanostructure obtained as a flake material;

[0057] FIG. 3C is a photograph of polymer-coated CNS pellets;

[0058] FIGS. 4A is a photograph of a free-standing graphite electrode film prepared by a solvent-free process that employed a CNS additive;

[0059] FIG. 4B is a photograph of a control graphite electrode film prepared by a solvent- free process without a processing aid;

[0060] FIGS. 5A and 5B are SEM images of cross-sections of a free-standing graphite electrode film that was prepared by a solvent-free process utilizing CNSs;Docket: 2020617PCT

[0061] FIG. 5C is a SEM image of a processing aid- free graphite electrode film prepared by a dry process;

[0062] FIG. 6A compares the electrode resistivity of graphite electrodes prepared by a solvent-free process utilizing CNSs and activated carbon for comparison;

[0063] FIG. 6B compares the rate capabilities of graphite electrodes prepared by a solventtree process utilizing CNSs relative to graphite electrodes prepared by a solvent-free process but using activated carbon, both being tested in half com-cells; insert in FIG. 6B shows 1stcycle efficiency;

[0064] FIG. 7 compares the tensile strength of NCM electrode films prepared by a solvent-free process utilizing a CNS additive and activated carbon for comparison;

[0065] FIG. 8 compares the electrode resistivity of NCM electrodes prepared by a solvent-free process utilizing a CNS additive and activated carbon for comparison;

[0066] FIG. 9 compares the tensile strength and elastic modulus of graphite / Si-C anode films prepared by two different solvent-free approaches;

[0067] FIG. 10 compares the tensile strength of films made with different CNS;

[0068] FIG. 11 compares the in-plane resistivity of electrodes made with different CNSs;

[0069] FIG. 12 shows dynamic light measurements for SiOx (as is) and a composite of SiOx- CNS powder obtained by the spray drying;

[0070] FIGs, 13 A and 13B shows the SEM images for dry graphite / Si-C anodes made with CNS5.

[0071] FIG. 14 compares the tensile strength and elastic modulus of NCM622 cathode films prepared by a solvent-free process utilizing a CNS5 only, CNT5 only, and CNS5 / CNT5 blends at two different ratios for comparison;

[0072] FIG. 15 compares the specific discharge capacity and rate capabilities of NCM622 electrodes prepared by a solvent-free process utilizing a CNS5 only, CNT5 only, and CNS5 / CNT5 blends at two different ratios, all being tested in full com-cells;Docket: 2020617PCT

[0073] FIG. 16 compares the capacity retention of NCM622 electrodes prepared by a solvent-free process utilizing a CNS5 additive and CNS5 / CNT5 blends at two different ratios, all being cycled in full com-cells;

[0074] FIG. 17 compares the tensile strength of NCM622 cathodes films prepared by a solvent-free process utilizing a CNS5 / CB3 blend and CB3 additive for comparison; and

[0075] FIG. 18 compares the composite volume resistivity of NCM622 cathodes prepared by a solvent-free process utilizing a CNS5 / CB3 blend and CB3 additive for comparison.DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0076] The disclosure now will be described more fully hereinafter with reference to the accompanying drawings, in which illustrative embodiments of the disclosure are shown. This disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0077] The disclosure generally relates to the manufacture of electrodes for electrochemical cells, in many cases for batteries such as, for instance, LIBs. In one example, the batteries of interest are rechargeable LIBs.

[0078] Typically, LIBs are named according to the acronyms for the electroactive material employed to form the cathode, often an intercalation compound. Embodiments described herein can be practiced with or adapted to various types of lithium ion batteries currently known in the art, such as, for instance, LCO (lithium cobalt oxide), LMO (lithium manganese oxide), NCM (lithium nickel cobalt manganese oxide), NCA (lithium nickel cobalt aluminum oxide), LCP (lithium cobalt phosphate), LFP (lithium iron phosphate), LFSF (lithium iron fluorosulfate), LTS (lithium titanium sulfide), or LIBs developed in the future.

[0079] In addition, principles described herein can be applied or adapted to lithium metal batteries, for instance, lithium-sulfur batteries that include a sulfur-containing cathode, to solid state batteries (SSB), or other devices.Docket: 2020617PCTIngredients Used

[0080] One aspect of the disclosure relates to a solvent-free method for preparing an electrode composition. Constituents employed to prepare the electrode composition include: an electroactive component (a material or combination of materials that participates in the electrochemical charge / discharge reactions of an electrochemical cell such as by absorbing or desorbing lithium); a binder, which can be a fibrill izable or a non-fibrillizable binder; and carbon nanostructures. Other ingredients can be added m some cases.Electroactive Materials

[0081] For many LIB anodes, the electroactive material (also simply referred to herein as “active material” or “AM”) is graphite, e.g., natural graphite, artificial graphite (e.g., massive artificial graphite (MAG)) or blends of both. Mesocarbon microbead (MCMB), mesophasepitch-based carbon fiber (MCF), vapor grown carbon fibre (VGCF) also can be employed. In other implementations, the active anode compound comprises, consists essentially of, or consists of silicon, such as, for instance, silicon-graphite composites, graphite containing nanosilicon (Si) or SiOx particles, Si composite or combinations thereof. Some active anode material can include lithium titanate.

[0082] Principles described herein also can be used with other active anode materials such as, for instance, those known or currently explored, or those to be developed in the future. Examples include but are not limited to: (a) intercalation / de-intercalatiou materials (e.g., carbon based materials, porous carbon, graphene, T1O2, LrfbisOv, and so forth); (b) alloy foe-alloy materials (e.g., Si, SiOx, doped Si, Ge, Sn, Al, Bi. SnO?., etc.); and (c) conversion materials (e.g., transition metal oxides (MmOy, NiO, Fe^Oy, CuO, Cm. O, MoO?., etc.), metal sulfides, metal phosphides and metal nitrides represented by the formula MxXy, where X = S, P, N)).

[0083] The amount of the active anode material employed can vary, depending on the particular type of energy storage device. In illustrative examples, the active anode component is present in the electrode composition m an amount of at least 80 % by weight, e.g., at least 85, 90 or 95 wt %, relative to the total weight of the (dry) electrode composition, e.g., in an amount ranging from 80% to 99%, or even 99.8 % by weight, such as, within the range of from about 80 to about 83, to about 85 wt %, to about 87, to about 90, to about 92, to about 95, to about 98Docket: 2020617PCTwt%; or from about 83 to about 85, to about 87, to about 90, to about 92, to about 95 to about 98, to about 99 wt%; or from about 85 to about 90, to about 93, to about 95, to about 98, to about 99 wt%; or from 85 to about 87, to about 90, to about 93, to about 98, to about 99 wt%; or from about 87 to about 90, to about 93, to about 95, to about 98, to about 99 wt %; or from about 90 to about 93, to about 95, to about 98, to about 99 wt %; or form about 93 to about 95, to about 98, to about 99 wt %; or form about 95 to about 98, to about 99 wt%; or from about 98 to about 99 wt %, relative to the total weight of the electrode composition. In other examples, the active anode material amount is in the range of 99 to 99.8 wt%.[00841 LIB cathodes can employ LCO, LMO, LMNO, NCM, NCA, LCP, LFP, LFSF or LTS, for example. Active cathode materials such as these are generally referred to herein as “lithium transition metal compounds”, e.g., “lithium transition metal oxides”. In addition to cathode materials based on intercalation chemistry, e.g., typically involving chemical reactions that transfer a single electron, other types of cathode materials (having lithium ions inserted into FeFO, for instance) can transfer multiple electrons through more complex reaction mechanisms, called conversion reactions. Other active cathode materials known in the art or developed in the future can be employed. One illustration involves a sulfur-containing cathode.

[0085] In specific examples, the cathode composition is prepared using NCM (also referred to as “NMC”) or NCA.

[0086] NCM can be represented by the formula Liwx(NiyCoi-y-zMnz)i-xO2, wherein x ranges from 0 to 1, y ranges from 0 to 1 (e.g., 0.3 -0.8), and z ranges from Oto 1 (e.g., 0.1-0.3). Examples of NCMs include Lil+x(Ni0.33CO0.33Mn0.33)l-xO2, Lii+x(Nio.4Coo.3Mno.3)i-x02, Lii+x(Nio.4Coo.2Mno.4)i-x02, Lii +x(Nio.4Coo.iMno.5)i ■.0. Lii+x(Nio.5Coo.iMno.4)i-x02, Lii+x(Nio.5Coo.3Mno.2)i- 02, Ln+x(Nio.5Coo.2Mno.3)i-x02, Lii+x(Nio.6Coo.2Mno.2)i-x02, Liwx(Nio.sCoo.iMno.i)i-x02 and Lil+x(Ni0.9C0.05Mn0.05)l-x02. Illustrative NCM materials that can be used include NCML11 (LiNi o.333Mno.333Coo.33302), NCM622 (LiNio.6Mno.2Coo.2O2) and others (providing the three metal components in different ratios).

[0087] NCA can be represented by the formula Lii+x(NiyCoi-y-zAlz)i-xO2, wherein x ranges from 0 to 1, y ranges from 0 to 1, and z ranges from 0 to 1. An example of an NCA is Lii+x(Nio.8Coo.isAlo.o5)i-x02.Docket: 2020617PCT

[0088] The amount of NCM or NCA in the electrode composition can vary, depending on the particular type of energy storage device. In some cases, the NCM or NCA is present in the electrode composition in an amount of at least 90% by weight, e.g., greater than 95%, often greater than 98%, or in some cases, at least 99% by weight, relative to the total weight of the electrode composition. In examples, the electroactive cathode material is present in an amount ranging from 90% to 99% or even to 99.8% by weight, relative to the total weight of the electrode composition, such as within a range of from about 90 to about 93, to about 95, to about 98, to about 99 wt %; or from about 93 to about 95, to about 98, to about 99 wt %; or from about 95 to about 98, to about 99; or from about 98 to about 99 wt %. In other examples, the active cathode material amount is in the range of 99 to 99.8 wt%.Binder

[0089] In addition to the active material, the method for preparing the electrode composition employs a binder. In general, the binder can be any semi-crystalline polymer.

[0090] In some embodiments, the binder is a fibrillizable binder. The fibrillizable binder can be provided m a binder component that consists of, consists essentially of, or comprises the fibrillizable binder.

[0091] Under certain processing conditions, e.g., high shear mixing in the presence of a fibrillizing agent, a fibrillizable binder is capable of producing fibrils, forming a network that can connect and support other particles present m the formulation. In more detail, it is believed that fibrillization of the binder generates a matrix, lattice, or web of fibrils that imparts mechanical structure to the electrode. In a product electrode, a fibrillized binder can be detected in SEM images which will show the presence of fibrils wrapped around at least a portion of at least some of the particles present, e.g., active material particles. Other indirect techniques that can be employed to evaluate relative degree of binder fibrillization include, for instance, energy-dispersive X-ray spectroscopy (EDX), powder rheology, tensile strength. EDX allows to map fluorine element distribution throughout the dry’ electrode and evaluate effectiveness of binder fibrillization. Powder rheology measures the cohesive interaction between the particles in the free-flowing electrode powder mix, while tensile strength testing measures strength of the freestanding electrode film, both being representative of the degree of binder fibrillization. In someDocket: 2020617PCTcases, poor or no fibrillization can be inferred for dry product electrode films that crumble or peel away from the substrate.

[0092] In some implementations the fibrillizable binder is a fibrillizable fluoropolymer, such as, for instance, polytetrafluoroethylene or PTFE. Other binders that can be considered fibrillizable include but are not limited to ultra-high molecular weight polypropylene, or polyethylene, co-polymers, or combinations thereof.

[0093] The fibrillizable binder (alone or as a constituent m a binder component (e.g., in a polymer blend)) can be present in the electrode composition in an amount of about 1 to about 10 % by weight, e.g., about 1-2, 2-3, 3-4, 4-5, 5-6, 6-7, 7-8, 8-9, 9-10 wt %. In one example, the fibrillizable binder is provided in an amount of about 5 wt %. In other examples the fibrillizable binder is present in an amount within a range of from about 1 to: about 2, about 3, about 4, about 5, about 6, about 7, about 8, about 9 wt %; or from about 2 to: about 3, about 4, about 5, about 6, about 7, about 8, about 9, about 10 wt %; or from about 3 to: about 4, about 5, about 6, about 7, about 8, about 9, about 10 wt %; or from about 4 to: about 5, about 6, about 7, about 8, about 9, about 10 wt %; or from about 5 to: about 6, about 7, about 8, about 9, about 10; or from about 6 to: about 7, about 8, about 9, about 10 wt %; or from about 7 to: about 8, about 9, about 10 wt %; or from about 8 to: about 9, about 10 wt %.

[0094] Not all situations, however, will employ a binder that is fibrillizable. Thus, some embodiments of the disclosure employ a binder component that consists of, consists essentially of, or comprises one or more non-fibrillizable binders. As used herein, the term “non- fibrillizable” binder refers to a binder that is difficult to fibnllize at the same conditions that are sufficient to fibrillate a “fibrillizable” binder. Nevertheless, even without reaching full fibrillization, practicing aspects of the disclosure (at the same or substantially the same processing conditions used for a fibrillizable counterpart) can still deform, e.g., stretch out, elongate, entangle, etc., many non-fibrillizable binders, often to a significant extent. Some benefits can be observed even with non-fibrillizable binders which, post processing, can be found to remain substantially undefomied. Such benefits can include improved adhesion (cathode or anode), and / or decreased side reactions and SEI layer formation (typically observed in anode formulations).Docket: 2020617PCT

[0095] Without wishing to be bound by a particular interpretation or mechanism, it is believed that fibrillization may be thought of as an extreme phenomenon, where the binder polymer (which may start out as a colloidal particle) becomes stretched out very thinly, forming very long (high aspect ratio) strands (ribbons) that can bridge across more than two electroactive particles, thereby holding them together. Practicing embodiments described herein also can lead to stretching (elongating) and / or entangling a non fibrillizable binder, forming composites, for example. Even if not fully fibrillated, such a “processed” non-fibrillizable binder can still serve as a glue, binding together and providing connectivity for the electroactive particles and adhesion to the current collector. Deformations of a non-fibrillizable binder can be observed by at least some of the techniques noted above.

[0096] In one example, the non-fibrillizable binder is a fluoropolymer such as polyvinylidene fluoride (PVDF). Other examples of binders that can be considered non- fibrillizable include poly(vinyldifluoroethylene co-hexafluoropropylene) (PVDF-HFP), polyimides, water-soluble binders, such as poly(ethylene) oxide, polyvinyl-alcohol (PVA), polyvinyl pyrrolidone (PVP), polyvinyl acetate, polyetliylene-co-vinyl acetate, some polyolefins, cellulose, or cellulose derivatives, to name a few.

[0097] Other possible non-fibrillizable binders include polyethylene and polypropylene other than ultra-high molecular weight, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene-butadiene rubber (SBR), butyl rubber, nitrile rubber, acrylonitrile¬ butadiene rubber (NBR) and its derivatives, e.g. hydrogenated nitrile butadiene rubber (HNBR), and fluoro rubber, copolymers and / or mixtures thererof.

[0098] In some implementations, the non-fibrillizable binder is a cellulose ester, a cellulose ether, a cellulose nitrate, a carboxyalkylcellulose, a cellulose salt or a cellulose salt derivative. In other examples, a microparticulate non-fibrillizable binder is selected from the group consisting of: cellulose, cellulose acetate, methylcellulose, ethylcellulose, hydroxylpropylcellulose (HPC), hydroxyethylcellulose (HEC), cellulose nitrate, carboxymethylcellulose (CMC), carboxyethylcellulose, carboxypropylcellulose, carboxyisopropylcellulose, sodium cellulose, sodium cellulose nitrate and sodium carboxyal ky 1 cel lulose.Docket: 2020617PCT

[0099] Non-fibrillizable binders can be present in the electrode composition in the same amounts as those used for fibrillizable binders. Other suitable amounts can be employed, as determined by routine experimentation, for example.

[0100] Fibrillizable binders in combination with non-fibrillizable binders also can be used. One example utilizes a combination of a PTFE and PVDF.CNSs

[0101] Electrode compositions routinely include ingredients such as conductive additives (e.g., conductive carbon additives or CCA), plasticizers and so forth. In the case of solvent-free processes, common techniques also call for a binder fibrillizmg (also known as “fibnllating”) agent or aid, typically AC.

[0102] It was discovered that conventional fibrillizmg aids (AC, for example) can be supplemented and often entirely replaced by carbon nanostructures.

[0103] The term “carbon nanostructures” (CNSs, singular CNS) refers to a plurality of carbon nanotubes (CNTs) that that are crosslinked in a polymeric structure by being branched, e.g., in a dendrimeric fashion, interdigitated, entangled and / or sharing common walls with one another. Operations conducted to prepare the compositions, electrodes and / or batteries described herein can generate CNS fragments and / or fractured CNTs. Fragments of CNSs are derived from CNSs and, like the larger CNS, include a plurality of CNTs that are crosslinked in a polymeric structure by being branched, interdigitated, entangled and / or sharing common walls. Fractured CNTs are derived from CNSs, are branched and share common walls with one another.

[0104] Highly entangled CNSs are macroscopic in size and can be considered to have a carbon nanotube (CNT) as a base monomer unit of its polymeric structure. For many CNTs in the CNS structure, at least a portion of a CNT sidewall is shared with another CNT. While it is generally understood that every carbon nanotube in the CNS need not necessarily be branched, crosslinked, or share common walls with other CNTs, at least a portion of the CNTs in the carbon nanostructure can be interdigitated with one another and / or with branched, crosslinked, or common-wall carbon nanotubes in the remainder of the carbon nanostructure.Docket: 2020617PCT

[0105] As known in the art, carbon nanotubes (CNT or CNTs plural) are carbonaceous materials that include at least one sheet of sp2-hybridized carbon atoms bonded to each other to form a honey-comb lattice that forms a cylindrical or tubular structure. The carbon nanotubes can be single-walled carbon nanotubes (SWCNTs) or multi-walled carbon nanotubes (MWCNTs). SWCNTs can be thought of as an allotrope of sp2-hybridized carbon similar to fullerenes. The structure is a cylindrical tube including six-membered carbon rings. Analogous MWCNTs, on the other hand, have several tubes in concentric cylinders. The number of these concentric walls may vary, e.g., from 2 to 25 or more. Typically, the diameter of MWNTs may¬ be 6 nm or more, m comparison to 0.7 to 2.0 nm for typical SWNTs.

[0106] In many of the CNSs used in this disclosure, the CNTs are MWCNTs, having, for instance, at least 2 coaxial carbon nanotubes. The number of walls present, as determined, for example, by transmission electron microscopy (TEM), at a magnification sufficient for analyzing the number of walls in a particular case, can be within the range of from 2 to 30 or so, for example: 4 to 30; 6 to 30; 8 to 30; 10 to 30; 12 to 30; 14 to 30; 16 to 30; 18 to 30; 20 to 30; 22 to 30; 24 to 30; 26 to 30; 28 to 30; or 2 to 28; 4 to 28; 6 to 28; 8 to 28; 10 to 28; 12 to 28; 14 to 28; 16 to 28; 18 to 28; 20 to 28; 22 to 28; 24 to 28; 26 to 28; or 2 to 26; 4 to 26; 6 to 26; 8 to 26; 10 to 26; 12 to 26; 14 to 26; 16 to 26; 18 to 26; 20 to 26; 22 to 26; 24 to 26; or 2 to 24; 4 to 24; 6 to 24; 8 to 24; 10 to 24; 12 to 24; 14 to 24; 16 to 24; 18 to 24; 20 to 24; 22 to 24; or 2 to 22; 4 to 22; 6 to 22; 8 to 22; 10 to 22; 12 to 22; 14 to 22; 16 to 22; 18 to 22; 20 to 22; or 2 to 20; 4 to 20; 6 to 20; 8 to 20; 10 to 20; 12 to 20; 14 to 20; 16 to 20; 18 to 20; or 2 to 18; 4 to 18; 6 to 18; 8 to 18; 10 to 18; 12 to 18; 14 to 18; 16 to 18; or 2 to 16; 4 to 16; 6 to 16; 8 to 16; 10 to 16; 12 to 16; 14 to 16; or 2 to 14; 4 to 14; 6 to 14; 8 to 14; 10 to 14; 12 to 14; or 2 to 12; 4 to 12; 6 to 12; 8 to 12; 10 to 12; or 2 to 10; 4 to 10; 6 to 10; 8 to 10; or 2 to 8; 4 to 8; 6 to 8; or 2 to 6; 4-6; or 2 to 4.

[0107] Since a CNS is a polymeric, highly branched and crosslinked network of CNTs, at least some of the chemistry observed with individualized CNTs may also be carried out on the CNS. In addition, some of the atractive properties often associated with using CNTs also are displayed in materials that incorporate CNSs. These include, for example, electrical conductivity, atractive physical properties including good tensile strength when integrated into a composite, such as a thermoplastic or thermoset compound, thermal stability (sometimesDocket: 2020617PCTcomparable to that of diamond crystals or in-plane graphite sheets) and / or chemical stability, to name a few.

[0108] CNSs, however, bring about further advantages. For example, without wishing to be held to a particular interpretation, it is believed that the combination of its length, branching, crosslinking, and wall sharing among the carbon nanotubes in a CNS reduces or minimizes the van der Waals forces that are often problematic when using individualized carbon nanotubes in a similar manner. These CNS features also contribute to forming significant electrical connections or pathways in electrode and battery applications.

[0109] Thus, as used herein, the term “CNS” is not a synonym for individualized, unentangled structures such ordinary nanotubes (or for other “monomeric” fullerenes, the term “fullerene” broadly referring to an allotrope of carbon in the form of a hollow sphere, ellipsoid, tube, or other shape).

[0110] For instance, even though CNTs can be considered building blocks in CNS materials, significant differences exist between CNTs that are part of or are derived from a CNS and “ordinary”, “fresh” or “pristine” CNTs, which are typically provided in individualized form, as manufactured commercially). For example, fresh CNTs are known to contain fair amounts of catalyst and support residuals. These species can be detected by techniques such as SEM, TEM, inductively coupled plasma atomic emission spectroscopy or ICP-AES, etc., and are not typically observed when examining CNSs.

[0111] Further features can be used to describe CNTs present in or derived from CNSs; at least some can be relied upon to distinguish such CNTs from ordinary CNTs (or other nanomaterials). For example, a CNT present in or derived from a CNS will typically have a diameter that is no greater than about 50 nanometers (nm), often within a range from about 2 to about 30 nanometers (nm), such as within the range of from about 2 to about 5, to about 10, to about 15, to about 20, to about 25 nm; or from about 5 to about 10, to about 15, to about 20, to about 25, to about 30 nm; or from about 10 to about 15, to about 20, to about 25, to about 30 nm; or from about 15 to about 20, to about 25, to about 30 nm; or from about 20 to about 25, to about 30 nm; or from about 25 to about 30 nm. In one example, the CNTs present in the CNSDocket: 2020617PCTstructure or derived from CNSs have an average diameter within a range from about 2 nm to about 30 nm, determined by TEM imaging for at least 100 individual tubes.

[0112] In some embodiments, at least one of the CNTs present in or derived from CNSs has a length that is equal to or greater than 2 microns, as determined by SEM. For instance, at least one of the CNTs will have a length within a range of from 2 to 2.25 microns; from 2 to 2.5 microns; from 2 to 2.75 microns; from 2 to 3.0 microns; from 2 to 3.5 microns; from 2 to 4.0 microns; or from 2.25 to 2.5 microns; from 2.25 to 2.75 microns; from 2.25 to 3 microns; from 2.25 to 3.5 microns; from 2.25 to 4 microns; or from 2.5 to 2.75 microns; from 2.5 to 3 microns; from 2.5 to 3.5 microns; from 2.5 to 4 microns; or from 3 to 3.5 microns; from 3 to 4 microns; of from 3.5 to 4 microns or higher.

[0113] More than one, e.g., a portion such as a fraction of at least about 0.1%, at least about 1%, at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40, at least about 45%, at least about 50% or even more than one half, of the CNTs, as determined by SEM, can have a length greater than 2 microns, e.g., within the ranges specified above.

[0114] The morphology of CNTs present in a CNS, in a fragment of a CNS or in a fractured CNT derived from a CNS will often be characterized by a high aspect ratio, with lengths typically more than 100 times the diameter, and in certain cases much higher. For instance, in a CNS (or CNS fragment), the length to diameter aspect ratio of CNTs can be within a range of from about 200 to about 1000, such as, for instance, from 200 to 300; from 200 to 400; from 200 to 500; from 200 to 600; from 200 to 700; from 200 to 800; from 200 to 900; or from 300 to 400; from 300 to 500; from 300 to 600; from 300 to 700; from 300 to 800; from 300 to 900; from 300 to 1000; or from 400 to 500; from 400 to 600; from 400 to 700; from 400 to 800; from 400 to 900; from 400 to 1000; or from 500 to 600; from 500 to 700; from 500 to 800; from 500 to 900; from 500 to 1000;or from 600 to 700; from 600 to 800; from 600 to 900; from 600 to 1000; from 700 to 800; from 700 to 900; from 700 to 1000; or from 800 to 900; from 800 to 1000; or from 900 to 1000.

[0115] It has been found that in CNSs, as well as in structures derived from CNSs (e.g., in fragments of CNSs or in fractured CNTs) at least one of the CNTs is characterized by a certainDocket: 2020617PCT“branch density”. As used herein, the term “branch” refers to a feature in which a single carbon nanotube diverges into multiple (two or more), connected multiwall carbon nanotubes. One embodiment has a branch density according to which, along a two-micrometer length of the carbon nanostructure, there are at least two branches, as determined by SEM. Three or more branches also can occur.

[0116] Further features (detected using TEM or SEM, for example) can be used to characterize the type of branching found in CNSs relative to structures such as Y-shaped CNTs that are not derived from CNSs. For instance, whereas Y-shaped CNTs, have a catalyst particle at or near the area (point) of branching, such a catalyst particle is absent at or near the area of branching occurring in CNSs, fragments of CNSs or fractured CNTs.

[0117] In addition, or in the alternative, the number of walls observed at the area (point) of branching in a CNS, fragment of CNS or fractured CNTs, differ from one side of the branching (e.g., before the branching point) to the other side of this area (e.g., after or past the branching point). Such a change in in the number of walls, also referred to herein as an “asymmetry” in the number of walls, is not observed with ordinary Y-shaped CNTs (where the same number of walls is observed in both the area before and the area past the branching point).

[0118] Diagrams illustrating these features are provided in FIGS. 1A and IB. Shown in FIG. 1 A, is an exemplary Y-shaped CNT 11 that is not derived from a CNS. Y-shaped CNT 11 includes catalyst particle 13 at or near branching point 15. Areas 17 and 19 are located, respectively, before and after the branching point 15. In the case of a Y-shaped CNT such as Y-shaped CNT 11, both areas 17 and 19 are characterized by the same number of walls, i.e., two walls in the drawing.

[0119] In contrast, in a CNS (FIG. 1B), a CNT building block 111, that branches at branching point 115, does not include a catalyst particle at or near this point, as seen at catalyst devoid region 113. Furthermore, the number of walls present in region 117, located before, prior (or on a first side of) branching point 115 is different from the number of walls in region 119 (which is located past, after or on the other side relative to branching point 115. In more detail, the three- walled feature found in region 117 is not carried through to region 119 (which in the diagram of FIG. 1B has only two walls), giving rise to the asymmetry mentioned above.Docket: 2020617PCT

[0120] These features are highlighted in the TEM images of FIGS. 2A and 2B and SEM images of FIGS. 2C and 2D

[0121] In more detail, the CNS branching in TEM region 40 of FIG. 2A shows the absence of any catalyst particle. In the TEM of FIG. 2B, first channel 50 and second channel 52 point to the asymmetry in the number of walls featured in branched CNSs, while arrow 54 points to a region displaying wall sharing. Multiple branches are seen in the SEM regions 60 and 62 of FIGS. 2C and 2D, respectively.

[0122] In some embodiments, a given CNS is part of an entangled and / or interlinked network of CNSs. Such an interlinked network can contain bridges between CNSs.

[0123] Suitable techniques for preparing CNSs are described, for example, in U. S. Patent Application Publication No. 2014 / 0093728 Al, published on April 3, 2014, U. S. Patent Nos.8,784,937B2; 9,005,755B2; 9,107,292B2; and 9,447,259B2. The entire contents of these documents are incorporated herein by this reference.

[0124] As seen in these documents, a CNS can be grown on a suitable substrate, for example on a catalyst-treated fiber material. The product can be a fiber-containing CNS material. In some cases, the CNSs are separated from the substrate on which the carbon nanostructures are initially formed. In many implementations of the present disclosure, the CNSs employed are free of any growth substrate. For instance, the CNSs can be provided in the form of flakes obtained when CNSs are removed from the growth substrate. As used herein, the term “flake material” refers to a discrete particle having finite dimensions. As described in US 2014 / 0093728A1, a carbon nanostructure obtained as a flake material (i.e., a discrete particle having finite dimensions) exists as a three-dimensional microstructure due to the entanglement and crosslinking of its highly aligned carbon nanotubes. The aligned morphology is reflective of the formation of the carbon nanotubes on a growth substrate under rapid carbon nanotube growth conditions (e.g., several microns per second, such as about 2 microns per second to about 10 microns per second), thereby inducing substantially perpendicular carbon nanotube growth from the growth substrate. Without being bound by any theory’ or mechanism, it is believed that the rapid rate of carbon nanotube growth on the growth substrate can contribute, at least in part, to the complex structural morphology of the carbon nanostructure. In addition, the bulk densityDocket: 2020617PCTof the CNS can be modulated to some degree by adjusting the carbon nanostructure growth conditions, including, for example, by changing the concentration of transition metal nanoparticle catalyst particles that are disposed on the growth substrate to initiate carbon nanotube growth. In embodiments described herein, the CNSs are free of the growth substrate employed in their manufacture.

[0125] Shown in FIG. 3A, for instance, is an illustrative depiction of a CNS flake material after isolation of the CNS from a growth substrate. Flake structure 100 can have first dimension 110 that is in a range from about 1 nm to about 35 pm thick, particularly about 1 nm to about 500 nm thick, including any value in between and any fraction thereof. Flake structure 100 can have second dimension 120 that is in a range from about 1 micron to about 750 microns tall, including any value in between and any fraction thereof. Flake structure 100 can have third dimension 130 that can be in a range from about 1 micron to about 750 microns, including any value in between and any fraction thereof. Two or all of dimensions 110, 120 and 130 can be the same or different.

[0126] For example, in some embodiments, second dimension 120 and third dimension 130 can be, independently, on the order of about 1 micron to about 10 microns, or about 10 microns to about 100 microns, or about 100 microns to about 250 microns, from about 250 to about 500 microns, or from about 500 microns to about 750 microns.

[0127] Shown in FIG. 3B is a SEM image of an illustrative carbon nanostructure obtained as a flake material. The carbon nanostructure shown in FIG. 3B exists as a three-dimensional microstructure due to the entanglement and crosslinking of its highly aligned carbon nanotubes.

[0128] A flake structure can include a webbed network of carbon nanotubes in the form of a carbon nanotube polymer (i.e., a “carbon nanopolymer”) having a molecular weight in a range from about 15,000 g / mol to about 150,000 g / mol, including all values in between and any fraction thereof. In some cases, the upper end of the molecular weight range can be even higher, including about 200,000 g / mol, about 500,000 g / mol, or about 1,000,000 g / mol. The higher molecular weights can be associated with carbon nanostructures that are dimensionally long. The molecular weight can also be a function of the predominant carbon nanotube diameter and number of carbon nanotube walls present within the carbon nanostructure. The crosslinkingDocket: 2020617PCTdensity of the carbon nanostructure can range between about 2 mol / cm3to about 80 mol / cnr’. Typically, the crosslinking density is a function of the carbon nanostructure growth density on the surface of the growth substrate, the carbon nanostructure growth conditions and so forth. It should be noted that the typical CNS structure, containing many, many CNTs held in an open web-like arrangement, removes Van der Wall’s forces or diminishes their effect. This structure can be exfoliated more easily, which makes many additional steps of separating them or breaking them into branched structures unique and different from conventional CNTs.

[0129] The flakes can be further processed, e.g., by cutting or fluffing, operations that can involve mechanical ball milling, grinding, blending, etc., chemical processes, or any combination thereof.

[0130] Thus, in addition to the flakes described above, the CNS material can be provided as granules, pellets, powders, or as other loose particles. A photograph of CNSs in pellet form is presented in FIG. 3C.

[0131] Pellets (or other loose particulate CNSs such as granules, powders, etc.) can having a typical particle size within the range of from about 0.5 mm to about 1 cm, for example, from about 0.5 mm to about 1 mm, from about 1 mm to about 2 mm, from about 2 mm to about 3 mm, from about 3 mm to about 4 mm, from about 4 mm to about 5 mm, from about 5 mm to about 6 mm, from about 6 mm to about 7 mm, from about 7 mm to about 8 mm, from about 8 mm to about 9 mm or from about 9 mm to about 10 mm. In one example, the particles size is within a range from about 0.5 to about: 2, 4, 6, 8 or 10 mm; or from about 2 to about 4, 6, 8 or 10 mm; or from about 4 to about: 6, 8 or 10 mm; or from about 6 to about 8 or 10 mm; or from about 8 to about 10 mm.

[0132] Blends of CNSs having different particle sizes can be employed in some cases.

[0133] The CNSs can be “coated” (also referred to herein as “sized” or “encapsulated”) CNSs. In a typical sizing process, the coating is applied onto the CNTs that form the CNS. The sizing process can produce a partial or a complete coating that is non-covalently bonded to the CNTs and, in some cases, can act as a binder. In addition, or in the alternative, the size can be applied to already formed CNSs in an operation that can be thought of as post-coating (or post encapsulation). With sizes that have binding properties, CNSs can be formed into largerDocket: 2020617PCTstructures, granules or pellets, for example. In other embodiments the granules or pellets are formed independently of the sizing.

[0134] Coating amounts can vary. For instance, relative to the overall weight of the coated CNS material, the coating can be within the range, by weight, from about 0.1 % to about 0.5%; from about 0.5 % to about 1%; from about 1% to about 1.5%; from about 1.5% to about 2%; from about 2% to about 2.5%; from about 2.5% to about 3%; from about 3% to about 3.5%; from about 3.5% to about 4%; from about 4% to about 4.5%; from about 4.5% to about 5%; from about 5% to about 5.5%; from about 5.5% to about 6%; from about 6% to about 6.5%; from about 6.5% to about 7%; from about 7% to about 7.5%; from about 7.5% to about 8%; from about 8% to about 8.5%; from about 8.5% to about 9%; from about 9% to about 9.5%; or from about 9.5% to about 10%.

[0135] In specific implementations, the coating is in the range of from about 0.1 weight % to about 10 weight %, such as from about 0.1 to about: 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 wt %; or from about 0.5 to about 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10 wt %; or from about 1 to about: 2, 3, 4, 5, 6, 7, 8, 9 or 10 wt %; or from about 2 to about: 3, 4, 5, 6, 7, 8, 9 or 10 wt %; or from about 3 to about: 4, 5, 6, 7, 8, 9 or 10 wt %; or from about 4 to about: 5, 6, 7, 8, 9 or 10 wt %; or from about 5 to about: 6, 7, 8, 9 or 10 wt %; or from about 6 to about: 7, 8, 9 or 10 wt %; or from about 7 to about: 8, 9 or 10 wt %; or from about 8 to about 9 or 10 wt % or from about 9 to about 10 wt %.

[0136] In many cases, controlling the amount of coating (or size) reduces or minimizes undesirable effects on the properties of the CNS material itself. Low coating levels, for instance, are more likely to preserve electrical properties brought about by the incorporation of CNSs or CNS-derived (e.g., CNS fragments of fractured CNTs) materials in an electrode composition.

[0137] Various types of coating materials can be selected, including, for example, organic polymers, hybrid polymers, or others.

[0138] Some CNS coatings can be formed employing sizing solutions commonly used in coating carbon fibers or glass fibers. Specific examples include but are not limited to fluorinated polymers such as poly(vinyldifluoroethylene) (PVDF), poly(vinyldifluoroethylene-co-hexafluoropropylene) (PVDF-HFP), poly(tetrafluoroethylene) (PIPE), polyimides, and water-Docket: 2020617PCTsoluble binders, such as poly(ethylene) oxide, polyvinyl -alcohol (PVA), cellulose, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinyl pyrrolidone (PVP), and copolymers and mixtures thereof. In many implementations, the CNSs used are treated with a polyurethane (PU), a thermoplastic polyurethane (TPU), or with polyethylene glycol (PEG).

[0139] Polymers such as, for instance, epoxy, polyester, vinylester, poly etherimide, poly etherketoneketone, poly phthalamide, poly etherketone, poly etheretherketone, polyimide, phenol-formaldehyde, bismaleimide, acrylonitrile-butadiene styrene (ABS), polycarbonate, polyethyleneimine, polyurethane, polyvinyl chloride, polystyrene, polyolefins, polypropylenes, polyethylenes, polytetrafluoroethylene, elastomers such as, for example, polyisoprene, polybutadiene, butyl rubber, nitrile rubber, ethylene-vinyl acetate polymers, silicone polymers, and fluorosilicone polymers, combinations thereof, or other polymers or polymeric blends can also be used in some cases. In order to enhance electrical conductivity, conductive polymers such as, for instance, polyanilines, polypyrroles and polythiophenes can also be used.

[0140] In some implementations, the coating is prepared using a fibrillizable binder such as a fluoropolymer, e.g., polytetrafluoroethylene or PTFE. Other possible fibrillizable binders, such as those listed above, can be utilized. It is also possible to coat CNSs with at least one binder typically considered non-fibrillizable. The coating material can be the same as the binder employed in the solvent-free process.

[0141] With a web-like morphology, CNS materials can have relatively low bulk densities. As-produced carbon nanostructures can have an initial bulk density ranging between about 0.003 g / cm3to about 0.015 g / cm3. Further consolidation and / or coating to produce a carbon nanostructure flake material or like morphology can raise the bulk density to a range between about 0.1 g / cm³ to about 0.15 g / cm3. In some embodiments, optional modifications of the carbon nanostructure can be conducted to further alter the bulk density and / or another property of the carbon nanostructure. For instance, the bulk density of the carbon nanostructure can be further modified by forming a coating on the carbon nanotubes of the carbon nanostructure and / or infiltrating the interior of the carbon nanostructure with various materials. Coating the carbon nanotubes and / or infiltrating the interior of the carbon nanostructure can further tailor the properties of the carbon nanostructure for use in various applications. Moreover, forming aDocket: 2020617PCTcoating on the carbon nanotubes can desirably facilitate the handling of the carbon nanostructure. Further compaction can raise the bulk density, e.g., to an upper limit of about 1 g / cm3, with chemical modifications to the carbon nanostructure raising the bulk density to an upper limit of about 1.2 g / cm3. Specific examples utilize CNS materials having a bulk density within the range of from about 0.003 g / cm3to about 0.5 g / cm3, e.g., from about 0.003 g / cm3to about 0.015 g / cm3.

[0142] In many of the embodiments described herein, the CNSs powder employed have a Brunauer-Emmett-Teller (BET) surface area, measured, for example, according to ASTM D6556-10, that is within the range of 200 m2 / g - 400 m2 / g (for some coated CNS powder the BET area can be within the range of 100 m2 / g - 350 m2 / g).

[0143] Other CNSs properties relate to their physical form. Particle size, for example, is a property that can be determined by particle size distribution (PSD) techniques and / or scanning electrode microscopy (SEM). A particle size analyzer can be used to measure the intensity of scattered light by laser diffraction to conduct particle size measurement. As a laser beam is directed through a dispersed particulate sample, large particles will scatter light at small angles, while small particles will scatter the light at a larger angle. Average particle size (Dso) is the particle size range based on 50% in the particle size distribution of the dispersion.

[0144] Some of the CNSs employed are characterized by a BET surface area within a range from about 100 m2 / g to about 400 m2 / g, determined according to ASTM D6556-10.

[0145] Also of interest is the CNS particle size, a property that can be determined by particle size distribution (PSD) techniques and / or scanning electrode microscopy (SEM). For instance, a particle size analyzer measures the intensity of scattered light by laser diffraction. As a laser beam is directed through a dispersed particulate sample, large particles will scatter light at small angles, while small particles will scatter the light at a larger angle. Average particle size (Dso) is the particle size range based on 50% in the particle size distribution of the dispersion. In embodiments, the CNSs employed in the dry process described herein have an average particle size (D50) within a range of from about 5 to about 100 microns (pm), e.g., within a range from about 5 to about 50 microns. In many cases, the PSD of pristine CNS flakes is in the range fromDocket: 2020617PCT25 to 50 microns; processed (e.g., milled) CNSs can have a PSD within a range from about 10 to about 30 microns.

[0146] In many embodiments, the CNS-material employed has a 97% or higher CNT purity. Typically, anionic, cationic or metal impurities are very low, e.g., in the parts per million (ppm) range.

[0147] Illustrative examples of CNSs are those developed by Applied Nanostructured Solutions, LLC (ANS) (Massachusetts, United States). Various types of CNSs are commercially available from Cabot Corporation (Massachusetts, U. S. A.).

[0148] The CNSs used herein can be identified and / or characterized by various techniques. Electron microscopy, including techniques such as transmission electron microscopy (TEM) and scanning electron microscopy (SEM), for example, can provide information about features such as the frequency of specific number of walls present, branching, the absence of catalyst particles, etc. See, e.g., FIGS. 2A-2D.

[0149] Raman spectroscopy can point to bands associated with impurities. For example, a D-band (around 1350 cm-1) is associated with amorphous carbon; a G-band (around 1580 cm-1) is associated with crystalline graphite or CNTs). A G' band (around 2700 cm-1) is expected to occur at about 2X the frequency of the D band. In some cases, it may be possible to discriminate between CNS and CNT structures by thermogravimetric analysis (TGA).

[0150] In many cases, the carbon nanostructures employed can be thought of as providing at least one but typically more than one functions. A “multifunctional” additive can serve as binder fibrillating agents, as conductive additive (generating conductive networks, e.g., the long- range conductivity of the electrode), and / or as mechanical strengthening aid (imparting mechanical support, stability and / or flexibility to the electrode product, often the coating, layer or film typically applied onto the conductive substrate to form a battery electrode). Thus, in many cases, “multifunctional” carbon nanostructures can be defined as a material that effectively deforms or fibrillizes a binder employed in a solvent-free process; contributes to the electronic / ionic conductivity of the electrode; and / or provides mechanical benefits (e.g., improved flexibility, improved elastic modulus for the free-standing films or electrodes). In specific implementations, multifunctional CNSs can be thought of as being capable ofDocket: 2020617PCTfibrillizing a fibrillizable binder at a loading no greater than 5 weight percent (wt %), At this loading, the multifunctional carbon nanostructures also act as a carbon conductive additive, reducing the in-plane resistivity of the electrode. In many cases, mechanical benefits are obtained as well.

[0151] Without wishing to be held to a particular interpretation, it is believed that desirable multifunctional attributes may be associated with the porous characteristics (e.g., void volume) of the CNS flake or granule, surface roughness of CNS fragments, the electrical conductivity of the CNS material, and / or the mechanical strength of high-aspect-ratio tubular structure of CN S fragments. The particle size and surface chemistry characterizing some of the CNS materials employed may be other factors, enhancing, for example, fibrillizing properties.

[0152] Additional processing or modifications can further increase the multifunctional character of CNSs.

[0153] In one approach, CNS flakes are pre-milled (milled before mixing with the fibrillizable binder and / or electrode active material), using, for instance, a high shear mixing apparatus such as, for instance, jet mills, ball mills, extruders, homogenizers, etc. In some situations, the pre-milling operation can involve a solvent. If this is the case, the solvent is removed, e.g., by heat drying, freeze drying, or vacuum. Conducted before the fibrillization step, a pre- milling operation, optionally in conjunction with a drying step (if solvent is employed), can serve to detangle CNSs bundles, thus maximizing contact area with the binder and enhancing fibril formation. Without wishing to be held to a particular mechanism, it is possible that detangled CNSs may become incorporated into the binder more uniformly than CNS flakes and further suppress binder over- fibrillization (excessive thinning of the binder fibrils resulting in hardening, then snapping. Other detangling techniques could be employed.

[0154] In another approach, the CNSs entirely lack or have reduced numbers of oxygencontaining surface groups. The reduction or elimination of oxygen containing groups such as -OH, -O-, -COOH, etc., increases the hydrophobic character of the CNS additive and thus increases the affinity of the additive to a hydrophobic binder such as, for example, PTFE. One technique for removing oxygen-containing groups from CNSs is heat treatment, which can be conducted in a vacuum oven, for example.Docket: 2020617PCT

[0155] In addition to enhancing hydrophobicity, heat treatment can also improve the electrical conductivity of the CNS material and reduce or minimize impurities (e.g., metallic impurities, metal oxide fibers) that can interfere and negatively impact cyclic performance, hot storage and / or battery safety. Other techniques that can be employed to remove impurities, include, for instance, acid washing, a combination of heat treatment and acid washing, or another suitable technique.CNS-Polymer Composites

[0156] In further embodiments, a CNS material (optionally further processed by pre-milling, heat treating, acid washing, etc.) can be provided as one component in a composite material. Such a composite can include a polymeric constituent which can be present in the composite in any suitable amount. CNS-polymer composites can be made by routine techniques known in the art and can be provided in any suitable form such as powders, pellets, beads, granules, or other kinds of loose particulate materials. A CNS-polymer composite, for instance, can be prepared by dispersing CNSs (in the form of flakes, pre-milled, heat treated, and / or acid washed (as described above), or in another suitable form), in a polymer matrix.

[0157] Depending at least in part on the polymer content, specific types of composites that can be utilized include coated or encapsulated CNSs (such as described above), CNS-polymer composites, combinations thereof and so forth.

[0158] In a composite that contains relatively low polymer amounts, the amount of polymer (relative to the overall weight of the CNS-polymer composite, a coated CNS material, for example) can be within a range of from about 0.1 weight % to about 10 weight %, e.g., within the range, by weight, of from about 0.1% to about 0.5%; from about 0.5 % to about 1%; from about 1% to about 1.5%; from about 1.5% to about 2%; from about 2% to about 2.5%; from about 2.5% to about 3%; from about 3% to about 3.5%; from about 3.5% to about 4%; from about 4% to about 4.5%; from about 4.5% to about 5%; from about 5% to about 5.5%; from about 5.5% to about 6%; from about 6% to about 6.5%; from about 6.5% to about 7%; from about 7% to about 7.5%; from about 7.5% to about 8%; from about 8% to about 8.5%; from about 8.5% to about 9%; from about 9% to about 9.5%; or from about 9.5% to about 10%.Docket: 2020617PCT

[0159] Other, e.g., higher or significantly higher, polymer amounts can be used. A CNS-polymer composite, for instance, can contain CNSs in an amount within a range of from about 50 to about 99.9 wt %, and a polymer binder in an amount within a range of from about 0.1 to about 50 wt %.

[0160] In specific examples, a CNSs-polymer composite is prepared by combining CNSs with the polymer using CNSs in an amount within the range of from about 0.1 weight % to about 50 weight % relative to the overall weight of the composite, such as, for instance, from 0.1 to 1, from 0.1 to 10, from 0.1 to 20, from 0.1 to 30, from 0.1 to 40, from 0.1 to 50 wt%; or from 1 to 10, from 1 to 20, from 1 to 30, from 1 to 40, from 1 to 50 wt %; or from 10 to 20, from 10 to 30, from 10 to 40, from 10 to 50 wt %; or from 20 to 30, from 20 to 40, from 20 to 50 wt %; or from 30 to 40, from 30 to 50 wt %; or from 40 to 50 wt %).

[0161] While any CNS-polymer material can be considered, of particular interest are composites in which the polymeric material is the same as the binder used in the solvent-free process. In some cases, the selected polymeric material is “similar” to the binder, presenting, for example, interaction mechanisms and / or functional groups that are similar to those characterizing the binder.

[0162] In an illustrative example that employs a fibrillizable binder, e.g., PTFE, the CNS-polymer composite contains PTFE or a similar binder (e.g., modified PTFE, nitrile butadiene rubber, hydrogenated nitrile butadiene rubber and its modified versions). Other fibrillizable binders (such as PTFE and modified PTFE, for instance) can be utilized as the polymeric component in the CNS-polymer composite. Solvent-free processes conducted with non- fibrillizable binders can employ composites that include at least one non-fibrillizable binder, e.g., the same or a similar non-fibrillizable binder.

[0163] Without wishing to be bound by a particular theory, it is believed that CNSs-polymer composites, encapsulated CNSs, for instance, can increase dispersibility and surface interactions between CNSs and polymeric species and are expected to improve binder fibrillization or binder deformation.

[0164] In some embodiments, the polymer present in the composite provides at least a portion of the binder necessary to conduct the dry process. In one example, the entire binderDocket: 2020617PCTcomponent is supplied to the process via a CNSs-polymer composite, eliminating the need for separately adding binder as a discrete ingredient.CNS Composites with Active Anode Materials (CNS-AAM)

[0165] In some cases, it may be beneficial to pre-make composite particles comprising CNS and an active anode material (such as silicon, SiOx, Si / C, graphite and combination thereof) and subsequently utilize the resulting composite as a loose particulate material in a dry fabrication process such as described herein.

[0166] Using a CNS-AAM composite can address several process related issues relating to the lack of consistency in the feeding of multiple dry powders with various properties and fibrilization ability, homogeneity and uniformity of the dry electrodes made with multiple constituents, consistent process operation and yield, and others. Also advantageous with premade CNS-AAM composites is the placement of the conductive web-like network of CNS on the surface A AM In turn, this helps to roughen the surface of AAM for the binder processing, e.g., fibrilization, utilize CNS more effectively as the conductive agent (minimize the loading of conductive additive), restrict AAM swelling and pulverization during the battery operation, and so forth.

[0167] CNS-AAM particles can be made by various methods. For example, AAM and CNS can be dispersed into a slurry with small amount of an organic binder and subsequently dried. Alternatively, or in addition, the individual slurries of AAM and CNS can be combined, mixed and subsequently dried to make CNS-AAM powder. Suitable solvents for the slurries include aqueous solvents, alcohols or their combination. Solvent levels in the slurry can be in a range from about 30% to about 90%.

[0168] The drying methods may include oven drying, freeze drying and spray drying, for example. Specific implementations rely on spray drying, as this technique can generate powders with small and consistent particle sizes with a range between sub-micron to several tens of microns, attributes that can be advantageous for the particle feeds into the dry process.

[0169] Binders that can be used to prepare CNS-AAM composites include but are not limited to water soluble polymeric binders, aqueous emulsions, or two parts cross-linkable components. Examples of organic binders that can be employed include carboxymethylDocket: 2020617PCTcellulose (CMC), cellulose derivatives, SBR, polyvinyl alcohol and its derivatives, polyacrylic acid and its salts, polyurethanes, styrene maleic anhydride resms, polyimides and its derivatives, aqueous emulsions of PTFE, PVDF and others. In many examples, the amount of the organic binder in the slurry does not exceed 20 wt% with respect to CNS-AAM composition on a dry basis; often, the organic binder in the slurry is less than or equal to 10 wt%.

[0170] Thus, in general, the CNSs constituent or component employed to prepare the electrode compositions, films, electrodes and / or batteries can consist of, consist essentially of or comprise CNSs in the form of uncoated flakes or pellets, coated (with binder material, for instance) CNS flakes, coated CNS pellets, pulverized (pre-milled) powders of coated or uncoated CNSs, modified, e.g., heat treated flakes, coated heat-treated flakes, CNS-polymer composites, the composites that contain CNSs as well as an active anode material, and so forth. In some cases, TEM, X-ray tomography or other techniques could be used to determine the type of CNSs employed. Good multifunctional properties often are reflected in the quality of the film, electrode or battery product obtained.

[0171] Some implementations of the disclosure utilize more than one type of CNSs. In one example, neat CNS flakes are combined with a second CNS material, a CNSs-polymer composite, for instance. In another, CNSs that have not been further processed for increased multifunctionality are combined with a heat-treated, pre-milled, acid-washed or otherwise processed CNS material.Blends Containing CB and / or CNTs

[0172] The solvent-free process for electrode fabrication described herein can employ CNSs in combination with one or more non-CNS material(s). Examples of non-CNS materials that can be used include carbon blacks (CBs) and / or carbon nanotubes (CNTs). In some cases, the CB and / or the CNTs is / are multifunctional, providing two or more desirable features, functioning as a fibrillizing agent; as conductive carbon additive; and / or as a mechanical reinforcement. Combinations of materials that include two or more of CNSs, CB and CNTs also are referred to herein as “blends”. In practice, blend components (CNSs, CB, CNTs) can be provided in a pre-mixture (pre-blend) of two or more constituents, or individually.Docket: 2020617PCT

[0173] For some applications, the wt % ratio of CNSs to a combination (blend) that comprises CB and / or CNTs is within a range from 1:99 to 99:1, e.g., in a range from 1:19 to 1:1. The weight % content of CNS in a blend comprising CNSs together with CB and / or CNTs can be within a range from about 1 to about 99%, e.g., from about 5 to about 50 wt %.CBs

[0174] As known, CBs are materials that exist in the form of aggregates, which, in turn, are formed of CB primary particles. In most cases, primary particles do not exist independently of the CB aggregate. While the primary particles can have a mean primary particle diameter within the range of from about 10 nanometers (nm) to about 70 nm, e.g., from about 10 nm to about 15 nm; from about 10 nm to about 20 nm; from about 10 nm to about 25 nm; from about 10 nm to about 30 nm; or from about 10 nm to about 40 nm, the aggregates can be considerably larger. CB aggregates have fractal geometries and are often referred to in the art as CB “particles” (not to be confused with the “primary particles” discussed above).

[0175] Many types of CB are produced in a furnace-type reactor by pyrolyzing a hydrocarbon feedstock (FS) with hot combustion gases to produce combustion products containing particulate CB. Characteristics of a given CB often depend upon the conditions of manufacture and may be altered or modified, e.g., by changes in temperature, pressure, FS, stoichiometry, residence time, quench temperature, throughput, and other parameters.

[0176] As known in the art, CBs can be described by certain properties determined according to procedures, often standardized protocols, well known in the art. For instance, CBs can be characterized by their Brunauer-Emmett-Teller (BET) surface area, measured, for example, according to ASTM D6556-10; by their oil adsorption number (OAN), determined, for instance, according to ASTMD 2414-16; by their statistical thickness surface areas (STSAs), a property that can be determined by ASTM D 6556-10.

[0177] For a given CB, it may also be of interest, in some cases, to specify the ratio of its STSA to its BET surface area (STSA: BET ratio).

[0178] Crystalline domains of CBs can be characterized by an Lacrystallite size, as determined by Raman spectroscopy. La is defined as 43.5 * (area of G band / area of D band). The crystallite size can give an indication of the degree of graphitization, where a higher LaDocket: 2020617PCTvalue correlates with a higher degree of graphitization. Raman measurements of La were based on Gruber et al., " Raman studies of heat-treated carbon blacks," Carbon Vol. 32 (7), pp. 1377-1382, 1994, which is incorporated herein by reference. The Raman spectrum of carbon includes two major “resonance” bands at about 1340 cm⁻¹ and 1580 cm⁻¹, denoted as the “D” and “G” bands, respectively. It is generally considered that the D band is attributed to disordered sp2carbon, and the G band to graphitic or “ordered’ sp2carbon. Using an empirical approach, the ratio of the G / D bands and an La measured by Raman spectroscopy are highly correlated, and regression analysis gives the empirical relationship:La= 43.5 x (area of G band / area of D band),in which Lais calculated in Angstroms. Thus, a higher Lavalue corresponds to a more ordered crystalline structure.

[0179] The crystalline domains can be characterized by a Lccrystallite size. The Lccrystallite size was determined by X-ray diffraction using an X-ray diffractometer (PANalytical X’Pert Pro, PANalytical B. V.), with a copper tube, tube voltage of 45 kV, and a tube current of 40 mA. A sample of carbon black particles was packed into a sample holder (an accessory of the diffractometer), and measurement was performed over angle (29) range of 10° to 80°, at a speed of 0.14° / min. Peak positions and full width at half maximum values were calculated by¬ means of the software of the diffractometer. For measuring-angle calibration, lanthanum hexaboride (LaBs) was used as an X-ray standard. From the measurements obtained, the Lccrystallite size was determined using the Scherrer equation: Lc(Å) = K*λ / (β*cosθ), where K is the shape factor constant (0.9); X is the wavelength of the characteristic X-ray line of Cu Kα1(1.54056 A); P is the peak width at half maximum in radians: and 0 is determined by taking half of the measuring angle peak position (26).

[0180] Carbon black surface can be characterized by its surface energy (SEP), a property that can be determined by Dynamic Vapor (Water) Sorption (DVS) or water spreading pressure (described, for instance in US Patent No. 10,886,535 B2, issued on January 5, 2021, to Korchev et al. and incorporated herein by this reference.

[0181] Other techniques that can be used to study CBs include Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopyDocket: 2020617PCT(XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). FTIR spectroscopy is particularly useful for determining the nature of surface functional groups, while SEM / TEM techniques help to visualize the size and morphology of the particles. XPS is often used to determine the elemental composition of a material and TGA can provide information on the decomposition and oxidation characteristics of carbons.

[0182] Various CBs have been and continue to be developed for carbon conductive additive (CCA) applications. Attractive electroconductivity often combines a high specific surface and extensively developed structure (the arrangement of primary CB particles within an aggregate) and porosity. CBs that can be added to anode and / or cathodes compositions for LIBs prepared by a slurry process are described, for instance, in International Publication Nos. WO 2020 / 197670, to Cabot Corp., published on October 1, 2020 and WO 2020 / 197673, to Cabot Corp., published on October 1, 2020. Both are incorporated herein by this reference in their entirety.

[0183] Examples of commercially available CBs that can be effective CCAs include LUX® 50, LITX® 66, LITX® 200, LITX® 300, LITX® HI’, and LITX® MAX 90 carbon black particles available from Cabot Corporation; C-NERGY ™ C45, C-NERGY™ C65 and SUPER P® products from Imerys; Li-400, Li-250, Li-100 and Li-435 products from Denka; and the EC300 and EC600 products from Ketjen. The physical properties of illustrative CBs that can be employed as CCAs are presented as samples CB1 through CB5 in Table A below.Table APore Pore Pore(IG / (IG+ volume volume volume Total BET La LcSTSA, OAN, SEP, ID)) (cm3 / g) by (cm3 / g) by (cm CB y e A R3 / g) by Pore t p S, aman. XRD,m2 / g m. T / m2B. TH (pore B. TH (pore B. TH (pore Volume m2 / g mL / 100g A A% Cr size < 2 size 2nm- size (cm3 / g) Raman nm) 50nm) >50nm) CB1 999 446 265 6.7 25.5 37 13 0.015 0.66 1.54 2.21 CB2 1430 1415 605 2.5 20.9 32.4 12.8 NA 1.47 0.4 2.22 CB3 1491 507 387 12.5 18.8 26.1 NA 0.028 0.49 0.64 1.15 CB4 100 100 231 2.6 27.1 39.6 20.1 0.003 0.15 0.21 0.36CB5 131 97 230 28 13 23 15.3 NA 0.1 0.15 0.26>Docket: 2020617PCT

[0184] The carbon blacks employed in combination with the CNSs can have selected morphologies and / or surface chemistries and can provide two or more functions in the context of dry (solvent-free) electrode fabrication methods. In general a “multifunctional” carbon black (CB) can be defined as a CB that effectively deforms or fibrillizes a binder employed in a solvent-free process; contributes to the electronic / ionic conductivity of the electrode; and / or provides mechanical benefits. In specific implementations, a multifunctional CB can be thought of as being capable of fibrillizing a fibrillizable binder at a loading no greater than 5 weight percent (wt %). At this loading, the multifunctional CB also acts as a carbon conductive additive, reducing the in-plane and through-plane resistivity of the electrode. In many cases, mechanical benefits are obtained as well.

[0185] Multifunctional CBs are described, for example, in International Patent Application No. PCT / US23 / 64614, filed on March 17, 2023 and published as WO2023 / 183754 Al on September 28, 2023), with the title Solvent-Free Process for Preparing Lithium-Ion Batteries, which is incorporated herein by this reference.

[0186] Further to displaying the electroconductivity desired for LIB applications, other properties that can contribute to the multifunctionality of a CB involve one, more, or all of the following: surface roughness; surface chemistry (surface energy); particle strength; and particle size.

[0187] Typically, the CB surface roughness is related to the porosity of the particles, described, for instance, by a pore volume or pore size distribution. RMS surface roughness (calculated as the Root Mean Square of a surface’s measured microscopic peaks and valleys), for example, is known to correlate with surface pore size (e.g., similar order of magnitude). For instance, 2 nm pores can be indicative of an approximate RMS surface roughness of 1 nm.

[0188] Broadly, CB porosity can fall into one or more of the following categories: microporosity, defined by pores having diameter less than 2 nm; mesoporosity, defined by pores of a diameter ranging from 2 to 50 nm; and macroporosity, defined by pores having a diameter larger than 50 nm. Mean pore diameters and pore volumes can be determined in accordance with the techniques described in E. P. Barrett, L. G. Joyner, P. P. Halenda, J. Am. Chem. Soc.1951, 73, 373-380 (BJH method).Docket: 2020617PCT

[0189] In more detail, pore size distribution and pore volume in a carbon black can be determined by gas physisorption techniques such as nitrogen adsorption porosimetry, by measuring nitrogen gas adsorption using BET analysis followed by fitting the adsorption isotherms with different models, for example, the DFT (density function theory) and the BJH (Barrett- Joyner-Halenda) model, depending on the pore size region of interest. The BJH adsorption model technique was relied upon to fit the N2 adsorption isotherm and calculate the mesopore and macropore volumes presented herein.

[0190] Without wishing to be bound by a particular interpretation, it is believed that fibrillizing properties in multifunctional CBs are driven, at least in part, by the macroporosity of the particle, with macropores acting as anchoring points for interlocking the binder on the CB surface and stretching the binder into fibrils when high shear forces are applied.

[0191] While some carbon blacks are predominantly microporous materials, techniques exist for increasing porosity levels and / or producing CBs with tailored porosity types.

[0192] Contacting a CB starting material with an oxidant stream, for instance, can enhance porosity, in particular the mesoporous character of the CB product. Increasing the porosity of furnace blacks can be achieved by lengthening the residence time in the carbon black reactor, allowing the tail gas additional time to attack and etch the carbon surface. Another method relies on the addition of alkali earth metal ions to the carbon black feedstock, as these ions are known to catalyze the etching of the carbon black via the tail gas. Both techniques involve etching the CB “in-situ,” i.e., in the furnace reactor during production, to create carbon blacks with internal porosity. Some approaches that can be employed to modify carbon blacks are described, for instance, in U. S. Patent Nos. 8,895,142 B2, to Kyrlidis et al. and 10,087,330 B2, to Green et al., both being incorporated herein by this reference. Commercially, modified carbon blacks that can be utilized are available from Cabot Corporation. The properties of two illustrative CB specifications, namely samples CB2 and CB3, are presented in Table A, above. CB2 is the steam-etched version of CB5.

[0193] Fibrillizing properties also were found to depend on the surface chemistry or surface activity, a function that is often related to the manufacturing and / or heating process employed in preparing a particular CB. In many cases, surface chemistry or surface activity is associatedDocket: 2020617PCTwith oxygen-contaming groups found on the CB surface. In some embodiments, good fibnllating CB candidates lack or are depleted in oxygen-contaming surface groups, tending to be less hydrophilic (more hydrophobic).

[0194] For example, it is believed that effective fibrillization is driven, at least in part, by the affinity (adhesion) of CB to the binder, e.g., a fibrillizable binder. Thus, in one implementation, the preferred multifunctional CBs for successfully fibril hzing a binder such as PTFE are hydrophobic CBs (namely CBs that lack oxygen-contaming surface groups) and / or low surface energy CBs. Oxygen content can be measured by inert gas fusion. Low surface chemistry CBs have oxygen content within a range of from about 10 ppm to about 5000 ppm, e.g., from about 100 ppm to about 1000 ppm.

[0195] The presence of oxygen-contaming surface groups can be reduced or minimized by techniques such as heat treatment, or other surface modification approaches, as known in the art or as developed in the future. Surface-modified, e.g., heat-treated CBs, can be compared to and distinguished from regular carbon blacks by X-ray scattering, Raman spectroscopy, surface energy measurements by gas adsorption, or other techniques, as known in the art. In some cases, heat-treated and other surface-modified CBs also tend to display a reduced moisture uptake during processing. In Table A, CB1 is a heat-treated version of CB3, while CB4 is a heat-treated version of CB5.

[0196] Other CB properties to be considered in multifunctional CB candidates relate to their physical form. The CB particle size, for example, is a property that can be determined by particle size distribution (PSD) techniques and / or scanning electrode microscopy (SEM).

[0197] Also believed to play a role in the multifunctional character of the selected CB relates to the CB particle strength (displayed as particle hardness and / or particle cohesion). Particle strength allows the CB to effectively stretch the polymer binder; this along with particle roughness are important mechanical properties to achieve desirable binder fibrilization. Particle strength can be measured by individual pellet crash test, oscillatory viscoelastic measurements, or other techniques, as known in the art.

[0198] CBs can be provided as any number of loose particulate materials. Truly fluffy CB-contaming powders, for example, have been found to perform particularly well in some of theDocket: 2020617PCTdry processes tested. Such powdery materials can be characterized by their particle size, BET, and / or other properties. In many cases, powders employed have a density no greater than about 100 g / cm3.

[0199] Less fluffy CB particles, for example those obtained by jet-milling of CB pellets, can also be employed. Powder CBs can be pelletized using techniques and equipment known in the art. In one example, CB is pelletized with an emulsion solution of the binder utilized to form the electrode composition described herein. Other approaches employ an emulsion solution of a different binder, for instance, a binder that belongs to the same chemical family or has similar functionally active groups that can bind or otherwise interact with the binder employed to cany out the dry process. It is thought that, as a result, the energetics interaction of the pelletized CB with the binder used to prepare the electrode composition increases. Pellet sizes, which apply to pure CB and CB-polymer composites, can be within a range of from about 0.1 mm to about 5 mm.

[0200] Granules of carbon black also may be useful in some situations. In many cases, CB granules are a densified form of CB, without polymer being present in the final product. Generally, CB granules can be formed via a conventional pelletization process associated with CB production. Granular CB also can be provided as a composite such as a binder-containing granule.

[0201] Ground CB materials can have a particle size pellets, determined by laser diffraction, with D50 in the micron range, e.g., 1-10 gm, such as, for instance: 1 to 8, 1 to 6, 1 to 4, 1 to 2; or 2 to 10, 2 to 8, 2 to 6, 2 to 4; or 4 to 10, 4 to 8, 4 to 6; or 6 to 10, 6 to 8; or 8 to 10 microns. On the other hand, the particle size of CB granules or pellets, determined by sieving, can be in the range from sub millimeters (mm) to several mm. In specific examples, CB granules or pellets have a particle size from about 0.1 to about 3 mm, e.g., within a range from about 0.4 to about 1.5 mm. With some granules or pellets, an initial size can be reduced by grinding to various degrees to provide particles of roughly 10 microns down to below 1 micron. Some implementations utilize a combination of sizes.

[0202] The strength of the granules also can be considered. It can be minimized by forming the granule in the absence (or with minimal content) of binder during granule formation;Docket: 2020617PCTincreased strength of the granules can be achieved by using varying concentrations of binders and / or different types of binders. In some implementations, the binder employed to form the CB granules is the same or a similar binder to the binder employed m the dry process.

[0203] Some embodiments employ granules that are friable, under processing, e.g., fibrillization conditions. In such cases, the strength of the granules can be controlled so that the strength is high enough to fibrillate or deform the polymer binder and low enough for the granules to fall apart and release conducting and reinforcing carbon units, such as aggregates.

[0204] For many dry processes, the CNSs described above are employed in combination with a CB having a BET that is no greater than about 1600 m2 / g and an OAN that is no greater than about 650 ml / 100g.

[0205] The CB can have a BET that is no greater than about 1600 m2 / g, e.g., no greater than about: 1500, 1400, 1300, 1200, 1100, 1000, 900, 800, 700, 600, 500, 400, 300, 200, 100 or 50 m2 / g. The BET can be within a range of from about 35 to about 1600, such as, for example, within a range of from about 35 to about: 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500; or from about 100 to about: 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600; or from about 200 to about: 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600; or from about 300 to about: 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600; or from about 400 to about: 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600; or from about 500 to about: 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600; or from about 600 to about: 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600; or from about 700 to about 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600; or from about 800 to about: 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600; or from about 900 to about: 1000, 1100, 1200, 1300, 1400, 1500, 1600; or from about 1000 to about: 1100, 1200, 1300, 1400, 1500, 1600; or from about 1100 to about: 1200, 1300, 1400, 1500, 1600; or from about 1200 to about: 1300, 1400, 1500, 1600; or from about 1300 to about 1400, 1500, 1600; or from about 1400 to about: 1500, 1600; or from about 1500 to about 1600 m2 / g.

[0206] The CB employed in the dry process described herein can have an OAN that is no greater than about 650 ml / 100g, e.g., no greater than about 500, no greater than about 400, noDocket: 2020617PCTgreater than about 300, no greater than about 250, no greater than about 200, no greater than about 150, no greater than about 120 ml / 100g. The multifunctional CB can have an OAN within the range of from about 120 to about 650 ml / 100g, e.g., from about 120 to about 200, to about 300, to about 400, to about 500 ml / 100g, to about 600, to about 650 ml / 100g; or from about 200 to about 300, to about 400, to about 500, to about 600, to about 650 ml / 100g; or from about 300 to about 400, to about 500, to about 600, to about 650 ml / 100g; or from about 400 to about 500, or to about 600, to about 650 ml / 100g; or from about 500 to about 600, to about 650 ml / 100g; or from about 600 to about 650 ml / 100g.

[0207] LIB anodes can be prepared by a dry process that utilizes CNSs in combination with a CB having a BET within a range from about 35 to about 420 m2 / g, such as from about 35 to about 70, to about 100, to about 150, to about 200, to about 250, to about 300, to about 350 or to about 400 m2 / g; or from about 70 to about 100, to about 150, to about 200, to about 250, to about 300, to about 350, to about 400, or to about 420 m2 / g; or from about 100 to about 150, to about 200, to about 250, to about 300, to about 350, to about 400, or to about 420 m2 / g; or from about 150 to about 200, to about 250, to about 300, to about 350, to about 400, or to about 420 nr / g; or from about 200 to about 250, to about 300, to about 350, to about 400, or to about 420 m2 / g; or from about 250 to about 300, to about 350, to about 400, or to about 420 m2 / g; or from about 300 to about 350, to about 400, or to about 420 m2 / g; or from about 350 to about 400, or to about 420 m2 / g; or from about 400 to about 420 m2 / g.

[0208] For anode applications, the CB used in combination with CNSs can have an OAN within a range from about 120 to about 280 ml / 100g, such as for about 120 to about 175, or to about 230 ml / 100g; or from about 175 to about 230, or to about 280 ml / 100g; or from about 230 to about 280 ml / 100g.

[0209] LIB cathodes, employing, for instance, a lithium transition metal compound, can be prepared by a dry process that utilizes CNSs in combination with a CB having a BET within a range of from about 50 to about 1600 nr / g, such as from about 50 to about 200, to about 400, to about 600, to about 800, to about 1000, to about 1200, or to about 1400 m2 / g; or from about 200 to about 400, to about 600, to about 800, to about 1000, to about 1200, to about 1400, or to about 1600 m2 / g; or from about 400 to about 600, to about 800, to about 1000, to about 1200, to about 1400, or to about 1600 m2 / g; or from about 600 to about 800, to about 1000, to aboutDocket: 2020617PCT1200, to about 1400, or to about 1600 m2 / g; or from about 800, to about 1000, to about 1200, to about 1400, or to about 1600 m2 / g; or from about 1000, to about 1200, to about 1400, or to about 1600 m2 / g; or from 1200, to about 1400, or to about 1600 m2 / g; or from about 1400 to about 1600 m2 / g.

[0210] For cathode applications, the CB used in combination with CNSs can have an OAN within a range from about 120 to about 650 ml / 100g, such as from about 120 to about 250, to about 350, to about 450, to about 550, to about 650 ml / 100g; or from about 250 to about 350, to about 450, to about 550, to about 650 ml / 100g; or from about 350, to about 450, to about 550, to about 650 ml / 100g; or from about 450 to about 550, to about 650 ml / 100g; or from about 550 to about 650 ml / 100g.

[0211] In some cases, CBs that, together with CNSs, can be used to prepare LIB cathodes by the dry process described herein have a BET within a range of from about 50 to about 1600 m2 / g and an OAN within a range of from about 120 to about 650 ml / 100g. An illustrative CB that can be used to prepare a LIB cathode has a relatively high BET surface area (e.g., within a range of from about 1350 to about 1600 m2 / g), coupled with a relatively low OAN (e.g., within a range of from about 120 to about 220 ml / 100g). Another illustrative CB that can be used to prepare a LIB cathode has a BET surface area within a range of from about 80 to about 200 m2 / g and an OAN within a range of from about 140 to about 280 m2 / g, such as about 240 or lower, within a range of from about 140 to about 180 ml / 100g, for example. A further illustrative CB has a BET within a range of from about 500 to about 1600 m2 / g and an OAN within a range of from about 180 to about 650 ml / 100g. Yet another illustrative CB that can be used to prepare a LIB cathode has a BET surface area below 650 m2 / g (e.g., within a range of from about 500 to about 650 m2 / g) and an OAN within a range from about 180 to about 260 ml / 100g.

[0212] In many cases, CBs that can be used in combination with CNSs to prepare LIB anodes by the dry process described herein have a BET within a range of from about 35 to about 420 m2 / g and an OAN within a range of from about 120 to about 280 ml / 100g. An illustrative CB that can be used to prepare a LIB anode has a relatively low BET surface area (e.g., within a range of from about 50 to about 200 m2 / g) coupled with an OAN within a range of from about 1 0 to about 240 ml / 100g.Docket: 2020617PCT

[0213] Further to the BET and OAN properties mentioned above, many CBs that can be utilized in combination with CNSs are characterized by one or more of the following: a surface energy of about 25 mJ / m2or less, a Raman microcrystallme planar size (La) of at least about 10 A, a mesopore volume of at least about 0.05 cm3 / g, a macropore volume of at least about 0.2 cm3 / g, and a total mesopore and macropore volume of at least about 0.1 cm3 / g.

[0214] In more detail, the CB selected can have a surface energy (SEP) of less than or equal to 25 mJ / m2, e.g., within a range from about 1 to about 25, such as from about 1 to about 5, to about 10, to about 15, or to about 20 mJ / m2; or from about 5 to about 10, to about 15, to about 20, or to about 25 J / m2; or from about 10 to about 15, to about 20, or to about 25 mJ / m2; or from about 15, to about 20, or to about 25 mJ / m2; or from about 20 to about 25 mJ / nT'.

[0215] In many implementations, the CB has a La crystallite size of at least 10 A, for example, from 10 A to 40 A. In specific examples, the CB has a Lacrystallite size of from about 10 A to about 20 or to about 30 A; or from about 20 A to about 30 or to about 40; or from about 30 A to about 40 A.

[0216] With respect to porosity, the CB can have a mesopore volume of at least 0.05 cm3 / g, e.g., at least 0.1 cm3 / g. For some anodes, CNSs can be combined with a CB having a mesoporosity within a range from about 0.05 to about 0.5, while for some cathodes, CNSs can be used in combination with a CB having a mesoporosity within a range from 0.05 to about 2.0 cm3 / g.

[0217] Total mesopore and macropore volumes characterizing CBs that can be employed in combination with CNSs in the solvent-free process described herein can be at least 0.1 cm3 / g, typically higher. In one example, a CB used to prepare an anode composition has a total mesopore and macropore volume within a range of from about 0.1 to about 1.5 cm3 / g. In the case of cathodes, the CB can have a total mesoporosity and macroporosity within a range from about 0.1 to about 4.0 cm3 / g.

[0218] In some examples, the CB utilized in combination with CNSs has a % crystallinity of at least 20%, for example, from 20% to 50%, e.g., within a range of from about 20 to about: 25, 30, 35, 40, 45%; or from about 25 to about: 30, 35, 40, 45, 50%; or from about 30 to about:Docket: 2020617PCT35, 40, 45, 50%; or from about 35 to about: 40, 45, 50%; or from about 40 to about: 45, 50%; or from about 45 to about 50%.

[0219] In one illustration, the CB is selected to combine sufficient surface area (measured by BET N2 adsorption, for example) for best binder processing, e.g., fibrillization, while ensuring that the particular CB agglomerates employed (e.g., CB pellets or jet mill CB particles) can break down into particles small enough, e.g., less than 2 microns (pm), to maximize surface interactions between CB particle and the binder and thus effectively process, e.g., fibrillize, the binder.

[0220] More than one type of CB can be employed along with the CNS constituent. In some implementations, a multifunctional CB is provided along with a second CB (which may or may not be multifunctional), in a CB blend, for example. One example utilizes at least two carbon blacks having one or more characteristics that are different from one another, e.g., with respect to their BE T. Also possible are blends of carbon blacks with structure-OAN that are different from each other and / or blends of different carbon morphology, e.g., activated carbon or graphite with at least one CB. In specific examples, at least one component in the blend is a multifunctional CB.

[0221] Examples of suitable CB materials that can be utilized include commercially available specifications such as: Vulcan® series CB such as Vulcan® XCmax 22, a Black Pearls® senes CB such as Black Pearls 2000 carbon black, PBX® senes CB such as PBX 51, LITX® series CB such as LITX HP, LITX MAX 90, LITX93R from Cabot Corporation. CNSs + CNTs Blends

[0222] CNSs also can be provided in combination with conventional, also referred to herein as “ordinary”, “pristine” or “fresh” carbon nanotubes (CNTs). Typically, these CNTs are provided in individualized form, as manufactured commercially, or, in some cases, as custom- synthesized or processed. As discussed herein, these conventional, ordinary, pristine or fresh CNTs are not part of or derived from CNSs and are different and distinguishable from the CNTs entangled within the CNS structure, or from the fractured CNTs generated from CNSs during the dry’ process. The use of CNTs in solvent- free processes for preparing electrode compositions, films, electrodes, batteries, etc. is described m International Application No.Docket: 2020617PCTPCT / LS2024 / 20620, filed on March 20, 2024, published as WO 2024 / 196971 Al on September 26, 2024, and incorporated herein in its entirety by this reference.

[0223] Carbon nanotubes are carbonaceous materials, typically hydrophobic, characterized by at least one sheet of sp2-hybridized carbon atoms bonded to each other to form a honey-comb lattice that forms a cylindrical or tubular structure. The carbon atoms m a carbon nanotube are arranged in a hollow (e.g., cylindrical) structure, having a length that generally is greater than the radial diameter.

[0224] CNTs may have different morphologies, including single-walled carbon nanotubes (SWCNTs) or multi-walled carbon nanotubes (MWCNTs). SWCNTs can be thought of as an allotrope of sp2-hybridized carbon similar to fullerenes. The structure is a cylindrical tube including six-membered carbon rings. Double walled carbon nanotubes (DWCNTs) tend to have properties similar to SWCNTs. Analogous MWCNTs, on the other hand, have several tubes in concentric cylinders. The number of these concentric walls may vary, e.g., from 2 to 25 or more. Typically, the diameter of MWNTs may be 10 nm or more, in comparison to 0.7 to 2.0 nm for typical SWCNTs.

[0225] Based on chirality, CNTs are classified into armchair, zigzag and chiral nanotubes.

[0226] Due to strong van der Waals interactions, e.g., along their length, CNTs can easily form aggregates such as bundles, ropes or agglomerates. CNTs may occur as substantially parallel “forests”, in randomly tangled masses (“pillows”) of structured agglomerations, or other kinds of aggregates.

[0227] CNTs can provide excellent electrical and thermal conductivity, and good mechanical properties. With their great conductivity, carbon nanotubes are increasingly adopted as a conductive additive in lithium-ion battery electrodes. They can enhance battery performance indicators such as power, cycle life and energy density.

[0228] Both single and multiple walled CNTs can be used, as can mixtures of two or more different types of CNTs. In many embodiments, the CNTs are MWCN Ts. The number of walls present if MWCNTs are employed, determined, for example, by transmission electron microscopy (TEM), at a magnification sufficient for analyzing the number of wall in a particular case, can be within the range of from about 2 to about 30, for example: 4 to 30; 6 to 30; 8 to 30;Docket: 2020617PCT10 to 30; 12 to 30; 14 to 30; 16 to 30; 18 to 30; 20 to 30; 22 to 30; 24 to 30; 26 to 30; 28 to 30; or 2 to 28; 4 to 28; 6 to 28; 8 to 28; 10 to 28; 12 to 28; 14 to 28; 16 to 28; 18 to 28; 20 to 28; 22 to 28; 24 to 28; 26 to 28; or 2 to 26; 4 to 26; 6 to 26; 8 to 26; 10 to 26; 12 to 26; 14 to 26; 16 to 26; 18 to 26; 20 to 26; 22 to 26; 24 to 26; or 2 to 24; 4 to 24; 6 to 24; 8 to 24; 10 to 24; 12 to 24; 14 to 24; 16 to 24; 18 to 24; 20 to 24; 22 to 24; or 2 to 22; 4 to 22; 6 to 22; 8 to 22; 10 to 22; 12 to 22; 14 to 22; 16 to 22; 18 to 22; 20 to 22; or 2 to 20; 4 to 20; 6 to 20; 8 to 20; 10 to 20; 12 to 20; 14 to 20; 16 to 20; 18 to 20; or 2 to 18; 4 to 18; 6 to 18; 8 to 18; 10 to 18; 12 to 18; 14 to 18; 16 to 18; or 2 to 16; 4 to 16; 6 to 16; 8 to 16; 10 to 16; 12 to 16; 14 to 16; or 2 to 14; 4 to 14; 6 to 14; 8 to 14; 10 to 14; 12 to 14; or 2 to 12; 4 to 12; 6 to 12; 8 to 12; 10 to 12; or 2 to 10; 4 to 10; 6 to 10; 8 to 10; or 2 to 8; 4 to 8; 6 to 8; or 2 to 6; 4-6; or 2 to 4.

[0229] Specific embodiments employ CNTs having a diameter of 50 nanometers (nm) or less, such as within a range from about 2 nm to about 50 nm, as determined by TEM. For instance, the CNTs employed can have a diameter within a range of from about 2 to about: 5, 10, 20, 30, 40 nm; or from about 5 to about: 10, 20, 30, 40, 50 nm; or from about 20 to about: 30, 40, 50 nm; or from about 30 to about: 40, 50 nm; or from about 40 to about 50 nm.

[0230] CNTs can vary in length from about 10 nanometers (nm) to about 750 microns (pm), or higher. Thus, the CNTs can be from 10 nm to 100 nm, from 10 nm to 500 nm; from 10 nm to 750 nm; from 10 nm to 1 micron; from 10 nm to 1.25 micron; from 10 nm to 1.5 micron; from 10 nm to 1.75 micron; from 10 nm to 2 micron; or from 100 nm to 500 nm, from 100 nm to 750 nm; from 100 nm to 1 micron; from 100 to 1.25 micron; from 100 to 1.5 micron; from 100 to 1.75 micron from 100 to 2 microns; from 500 nm to 750 nm; from 500 nm to 1 micron; from 500 nm to 1 micron; from 500 nm to 1.25 micron; from 500 nm to 1.5 micron; from 500 nm to 1.75 micron; from 500 nm to 2 micron; from 750 nm to 1 micron; from 750 nm to 1.25 micron; from 750 nm to 1.5 micron; from 750 nm to 1.75 microns; from 750 nm to 2 microns; from 1 micron to 1.25 micron; from 1.0 micron to 1.5 micron; from 1 micron to 1.75 micron; from 1 micron to 2 microns; or from 1.25 micron to 1.5 micron; from 1.25 micron to 1.75 micron; from 1 micron to 2 microns; or from 1.5 to 1.75 micron; from 1.5 to 2 micron; or from 1.75 to 2 microns.

[0231] In some cases, the CNTs employed in the dry process described herein have an average length within a range of from about 1 microns to about 30 microns, such as within aDocket: 2020617PCTrange of from about 1 to about 5, from about 1 to about 10, from about 1 to about 15, from about 1 to about 20, from about 1 to about 25 microns; or from about 5 to about 10, from about 5 to about 15, from about 5 to about 20, from about 5 to about 25, from about 5 to about 30 microns; or from about 10 to about 15, from about 10 to about 20, from about 10 to about 25, from about 10 to about 30 microns; or from about 15 to about 20, from about 15 to about 25, from about 15 to about 30 microns; or from about 20 to about 25, from about 20 to about 30 microns; or from about 25 to about 30 microns.

[0232] In some embodiments, at least one of the CNTs has a length that is equal to or greater than 2 microns, as determined by SEM. In specific embodiments, more than one, e.g., a portion such as a fraction of at least about 0.1 %, at least about 1%, at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50% or even more than one half, of the CNTs, as determined by SEM, can have a length greater than 2 microns, e.g., within ranges specified above.

[0233] The morphology of CNTs will often be characterized by a high aspect ratio, with lengths typically more than 100 times the diameter, and in certain cases much higher.

[0234] CNTs also can be characterized by their surface area. Small-diameter single- wall CNTs, for example, can have specific surface areas up to approximately 3000 m2 / g, such as, for instance, up to about 1315 m2 / g, while large-diameter multi- wall CNTs often are characterized by specific surface areas no greater than about 1000 m2 / g.

[0235] In many of the embodiments described herein, CNSs are employed in combination with CNTs that have a Brunauer-Emmett-Teller (BE T) surface area, measured, for example, according to AS I’M D6556-10, that is less than about 500 nr / g, such as, for example, less than or equal to 400 m2 / g; less than or equal to 300 m2 / g (e.g., 200 m2 / g).

[0236] In some implementations, the BET surface area of the CNTs is within a range from about 80 to about 500, e.g., within a range of from 200 to about 500 m2 / g. In specific examples, the CNTs have a BET surface area within a range from about 80 to about: 100, 150, 200, 250, 300, 350, 400, 450, 500 m2 / g; or from about 100 to about: 150, 200, 250, 300, 350, 400, 450, 500 m2 / g; or from about 150 to about: 200, 250, 300, 350, 400, 450, 500 m2 / g; or from aboutDocket: 2020617PCT200 to about: 250, 300, 350, 400, 450, 500 m2 / g; or from about 250 to about: 300, 350, 400, 450, 500 m2 / g; or from about 300 to about: 350, 400, 450, 500 m2 / g; or from about 350 to about: 400, 450, 500 m2 / g; or from about 400 to about: 450, 500 m2 / g; or from about 450 to about 500 m2 / g.

[0237] The CNTs employed have a bulk density, calculated, for example, as a weight of CNT powder, free-fallen and untapped in the cylinder, divided by volume that the powder occupies, that can be within a range of from about 0.01 to about 0.3, e.g., from about 0.01 to about 0.2. In one illustration, the CNTs have a bulk density of about 0.03 g / cm3. Further consolidation, compacting or densification, measured by tapped density, can raise the bulk density to a range between about 0.03 g / cnr’ to about 0.5 g / cm3.

[0238] The CNTs used herein can be identified and / or characterized by various techniques. Electron microscopy, including techniques such as transmission electron microscopy (TEM) and scanning electron microscopy (SEM), for example, can provide information about features such as the frequency of specific numbers of walls present, tube diameter, length, branching, the presence of catalyst particles, etc. Ordinary (fresh or pristine) CNTs, for instance, are known to contain fair amounts of catalyst and support residuals; these species can be detected by techniques such as SEM, TEM, inductively coupled plasma atomic emission spectroscopy or ICP-AES, etc.

[0239] Raman spectroscopy is often used to characterize the state of carbon in carbonaceous materials. For example, a D-band (around 1350 cm-1) is associated with sp3- carbon, whereas a G band (around 1580 cm’1) is associated with the sp2- carbon in the graphite or CN Ts. A G' band (around 2700 cm’1) is expected to occur at about 2X the frequency of the D band. In some cases, it may be possible to discriminate between the CNTs employed to practice the disclosure and other carbon structures by thermogravimetric analysis (TGA).

[0240] Another property that can be considered relates to the physical form of the CNTs. In embodiments, the dry process described herein is conducted by using CNSs in combination with CNTs having a Dso within a range from about 5 to about 500 microns, e.g., within a range from about 5 to about 100 microns.

[0241] In many embodiments, the CNT-material employed has a 97% or higher CNT purity. Typically, anionic, cationic or metal impurities are low, e.g., in the parts per million (ppm)Docket: 2020617PCTrange. Often, the CNTs employed herein require no further additives to counteract Van der Waal s’ forces.

[0242] Commercially, examples of CNT materials that can be utilized include but are not limited to those available from Cabot Corporation under the tradename of ENERMAX® carbon nanotubes, from CNano under FT trade name, LG Chem under Lucan trade name. Some specific examples include ENERMAX 61, FT2000, Lucan BT1003M, and others.

[0243] Properties of some illustrative CNTs are shown in Table B below.Table BBulk PSD (pm) Diameter,CNT type BET, m2 / g density,nmg / cm3DsoCNT 1 265.5 9-12 0.12 133-135CNT 2 300.41 5-10 0.092 60CNT 3 225.59 10-20 0.16 55CNT 4 101.22 30-50 0.149 80CNT 5 261.6 9-12 0.0308 12-16CNT 6 268.8 5-10 0.0189 15-16CNT 7 2297 10-20 0.0614 11-15CNT 8 208.41 10-20 0.06 15CNT 9 91.2 30-50 0.0511 9-15

[0244] In specific embodiments the CNSs are combined with CNTs that are multifunctional (providing electrical conductivity, binder fibrillatmg properties and / or mechanical reinforcement). Additional processing or modifications can further enhance the multifunctional character of the CNTs.

[0245] In one approach, for example, the CNT material is pre-milled (milled before mixing with the fibrillizable binder and / or electrode active material) using, for instance, a high shear mixing apparatus such as, for instance, jet mills, ball mills, extruders, homogenizers, etc. In many cases, the pre-milling operation is a dry pre-mill, conducted without a solvent, in a dry¬ state, e.g., as a dry powder. In some situations, however, the pre-milling operation can involve a solvent. If this is the case, the solvent can be removed by heat drying, freeze drying, or vacuum. Conducted before the fibrillization step, a pre-milling operation, optionally inDocket: 2020617PCTconjunction with a drying step (if solvent is employed), can increase the electrochemical performance and may enhance the fibrillizmg potential of the CNTs. Pre-milling may also bring about positive mechanical effects in the film and / or electrode product. Without wishing to be bound to a particular interpretation, it is believed that the smaller particles can be more uniformly dispersed through the composition, thereby enhancing electrical and mechanical properties of the product (film or electrode). In Table B above, CNT5 is pre-milled (pulverized) version of CNT1, while CNT6, CNT7, and CNT9 are pre-milled (pulverized) versions of CNT2, CNT3, and CNT4, respectively.

[0246] In another approach, the CNTs employed entirely lack or have a reduced number of oxygen- containing surface groups. The reduction or absence of oxygen containing groups such as -OH, -O-, -COOH, etc., increases the hydrophobic character of the additive and thus increases the affinity of the additive to a hydrophobic fibrillizable binder such as PTFE. One technique for removing oxygen-containing groups from CNTs is heat treatment, which can be conducted in a vacuum oven, for example.

[0247] In addition to enhancing the hydrophobic character of the CNTs, heat treatment can also improve their electrical conductivity and reduce or minimize impurities (such as those left behind from the manufacture of the CN Ts) that can interfere and negatively impact cyclic performance, hot storage and / or battery safety. Other techniques that can be employed to remove impurities, include, for instance, acid washing, a combination of heat treatment and acid washing or other techniques. In some approaches, the acid treatment includes oxidation with HNOs, H2SO4, HC1, HF, alone or in any combinations thereof, or graphitization. Other possible approaches include wetting MWCNTs with dimethyl formamide (DMF), oxidized first, then suspended in nitric acid.) In Table B above, CNT7 is the acid washed version of CNTS.

[0248] In some implementations, CNT aggregates are tailored to have sufficient strength to fibrillate the binder, yet fall apart to some extent, generating smaller fragments that can be spread throughout the composition, yielding a uniform CNT distribution.

[0249] CNTs can be doped (with boron, for example), graphene-winged or otherwise treated.Docket: 2020617PCT

[0250] CNTs may undergo more than one process and / or modification. For example, CNTs may be both heat-treated and pre-milled.

[0251] Thus, in general, the solvent-free process described herein can employ CNSs in conjunction with a CNT additive without any further processing or modification (e.g., not comminuted (e.g., not pre-milled or pulverized), not heat-treated, not acid-washed, etc.), as pulverized (pre-milled) powders, as modified, e.g., heat treated CNTs, acid washed CNTs, and so forth. In some cases, TEM, X-ray tomography or other techniques could be used to determine the type of CNTs utilized. Good multifunctional properties often are reflected in the quality of the film, electrode or battery product obtained.

[0252] CNTs may form or be compounded to form mixtures of CNTs with various combinations and distributions of the above characteristics (number of walls, diameters, lengths, morphologies, orientations, etc.).Weight % ratios of CNSs to fresh CNTs can be within a range from about 99:1 to about 1:99. In embodiments, the ratio is from about 1:19 to about 1:1. For a dry process using a blend of CNSs and CNTs, the weight % of CNSs in the blend can be from 99: 1 to 1:99.CNSs + AC

[0253] The CNS additive can be combined with another, e.g., a conventional, fibnllizing agent, such as an AC.

[0254] As used herein, the term “fibnllizing aid” or “fibrillizmg agent” refers to a material that is other than the binder or active electrode material and that promotes filbnllization of a fibrillizable binder. “Additional” or “other” fibrillizmg aid or “additional” or “other” fibrillizing agent refers to a material other than (i.e., a material that excludes or is not) the CNS material, a CNS-contaming composite, a CNS -containing blend (e.g., with a multifunctional CB) such as described above. Typically, the additional fibnllization aid is not considered multifunctional.

[0255] CNSs also can be provided in combination with a substantially non-fibrillizing conductive additive, a conventional CCA, for instance. As used herein, the term “additional conductive additive” refers to a material other (i.e., a material that excludes or is not) the CNS material or a CNS-containing composite or CNS-containing blend. Typically, additional conductive additives lack or substantially lack fibrillization functionality.Docket: 2020617PCT

[0256] Plasticizers and / or other materials conventionally used in electrode compositions can be included as well.

[0257] Some illustrative examples utilize CNSs along with another (additional) material, e.g., a conventional fibrillizer such as AC, a hard carbon, graphite, graphenes, other non-fibrillizmg conductive additives, plasticizers, or combinations thereof. In some applications, CNSs are combined with AC in a ratio within a range of from about 95:5 to about 50:50.Preparing the Electrode Composition

[0258] Constituents described above can be used to prepare an electrode composition, which, in turn, can be used to prepare films, electrodes and / or batteries.

[0259] Many existing electrode manufacturing techniques used in the fabrication of an electrochemical cell include the formation of an electrode composition (anode or cathode) that can be applied (coated, extruded, laminated, etc.) onto a conductive substrate. In the composition, the active electrode material is mixed (blended) with a binder (e.g., polymers, resins, etc.), which serves to associate and hold together the active materials. Liquids used to dissolve or carry the binder material, plasticizers and / or other agents often are included.

[0260] Generally, in a conventional solvent-based process, the polymer binder and other components are mixed with a suitable solvent to form a slurry that can be applied onto the substrate. As the solvent is removed (e.g., during drying), the binder becomes increasingly sticky and adheres to the particles present and / or the substrate.Dry or Solvent-Free Approach

[0261] In contrast to slurry-based techniques, some of the embodiments described herein involve a “solvent-free” also referred to as a “dry” process. In such a solvent-free approach, some and often all constituents (e.g., active material, binder, additives, etc.) needed to prepare the electrode composition are provided as loose particulate materials, e.g., free flowing powders, flakes, pellets, beads, and so forth. Implementations described herein can include one or more operations designed to mix these constituents (using, for instance, equipment designed to blend loose particulate materials) as well as at least one operation designed to process the binder. Subjecting the binder to certain shear conditions, for example, can result in binder deformations,Docket: 2020617PCTe.g,, binder elongations, formation of binder strands, entanglements, and so forth. With some types of binders, this is referred to as binder “fibrillization”.

[0262] In the method described herein, the binder processing, e.g., fibrillization, operation is performed in the absence of solvent. To illustrate, shearing conditions suitable for fibrillizing a fibri llizable binder are applied to ingredients in dry, loose particulate form, without any solvent addition, to produce a dry composition that includes the fibrillized binder.

[0263] In some approaches, steps other than the binder processing step also are carried out in the absence of a solvent. In such cases, the entire method for preparing the electrode composition is conducted under dry conditions. For example, steps needed for mixing ingredients, as well as the binder processing operation are all performed in the absence of a solvent, to make a dry electrode composition.

[0264] In other approaches, solvent can be employed m at least one step other than the binder processing step.

[0265] Small solvent amounts can be used, for example, to moisten at least some of the particles being mixed. The solvent can be removed by standard drying techniques. It is expected that such low solvent levels can be removed completely or nearly so. In one illustration, solvent is used m an intermediate step, to pre-blend some of the components, for example. The solvent is then removed, e.g., by drying, followed by combining the dried pre-blend with one or more of the remaining components and binder processing. In another illustration, the solvent-free process described herein includes a step that is a wet (or paste) step, while other steps (typically the binder processing, e.g., fibrillization, operation) are conducted without adding solvent.

[0266] Principles described herein also apply to a process in which, before drying, the electrode composition contains solvent in an amount less than about 10 wt %. Such a process is described herein as “semi-dry” and involves a drying operation to produce an electrode composition (e.g., in loose (pourable), particulate form) that contains solvent in an amount not greater than about 1 wt %.

[0267] In one implementation, a CNS-AAM composite, such as described above, is prepared by combining a dispersion including CNSs and an active electrode material, followedDocket: 2020617PCTby a solvent removal step. The dry composite particles are then combined with the binder (also in dry form) and processed, e.g., fibrillized in the absence of solvent.

[0268] While the dry CNS-AAM composite can be prepared in one or more intermediate steps that are part of an overall manufacturing process, CNS-AAM dry particles can also be premade (pre-formed) in an entirely separate operation and, in one example, stored and / or shipped for later use, e.g., in an entirely solvent-free process for preparing an electrode composition. This can also be the case for other composites, pre-blends, etc. that are prepared in the presence of a solvent, then dried. In some implementations, an intermediate pre-blend or composite can be stored or shipped in wet form, with the solvent removal step taking place at a later time.

[0269] A specific example involves forming a dispersion in which CNSs, which can be part of a CNS constituent, are combined with a Si-containing active material. The dispersion is oven dried, freeze dried, spray dried, etc., to form a composite including CNSs and the Si-containing active material in the form of dry, loose particles, a powder, for instance. To prepare the electrode composition, typically as a loose particulate material, the dry composite particles are dry-mixed with a fibrillizable or non-fibrillizable binder, followed by processing the binder under solvent-free conditions.

[0270] For many applications, the amount of solvent employed is no greater than about and often less than 1 weight % of the entire product electrode composition (a composition containing electroactive material, processed, e.g., fibrillized, binder and other ingredients, an additive component, for instance). In illustrative examples, the amount of solvent employed is within a range of from about 0 to at most 1 wt %, such as from about 0 to about 0.2, to about 0.4, to about 0.6, to about 0.8 wt %; or from about 0.2, to about 0.4, to about 0.6, to about 0.8, to about 1 wt %; or from about 0.2 to about 0.4, to about 0.6, to about 0.8, to about 1 wt%; or from about 0.4 to about 0.6, to about 0.8, to about 1 wt %; or from about 0.6 to about 0.8, to about 1.0 wt %; or from about 0.8 to about 1 wt %, based on the total weight of ingredients being used.

[0271] In other situations (when conducting a semi-dry process, for instance), solvent can be added in amounts within a range of from about 0 to about 10 wt %, such as within a range of from about 0 to about 2, to about 4, to about 6 to about 8 wt %; or from about 2 to about 4, toDocket: 2020617PCTabout 6, to about 8, to about 10 wt %; or from about 4 to about 6, to about 8 to about 10 wt %; or from about 6 to about 8, to about 10 wt %; or from about 8 to about 10 wt %.

[0272] Using CNS-AAM composites can involve even higher solvent levels. In one example, a CNS dispersion can contain solvent in an amount of up to about 98,4 wt %, resulting in a slurry composed of CNSs, Si-containing particles, any additives (e.g., binders, crosslinkers, other conductive carbons, etc) and a solvent. The solvent can be removed by spray drying or another suitable drying method to make CNS-AAM dry composite.

[0273] Specific solvents that can be employed include solvents typically encountered in LIB production, such as, for instance NMP, acetone, alcohols, or water.

[0274] In some cases, finished products, e.g., films or electrodes prepared by a process described herein, can be recognized by the absence of detectable processing solvents or processing solvent residues. In contrast, a product obtained by wet (slurry) techniques will typically include detectable processing solvents and / or processing solvent residues.

[0275] Binder strings (tendrils) connecting active material particles and / or particles containing CNSs can be easily visualized using EDS, for example. This is not the case with similar films or electrodes prepared by wet techniques.

[0276] Moreover, electrode products or films prepared according to embodiments of the disclosure are expected to display a uniform or substantially uniform binder distribution across the electrode product or film thickness, as observed by EDS or another suitable technique. In contrast, films prepared by wet techniques will typically present less uniformity, with binder migrations towards a film surface being a common occurrence.

[0277] Whereas electrodes prepared by wet (slurry) processes are prone to cracking, a tendency that limits the potential thickness of the electrode, dry processes such as described herein make possible the preparation of thicker, e.g., greater than or equal to about 100 microns, electrodes.

[0278] While ingredients can be mixed and the binder processed, e.g., fibrillized, entirely in the absence of solvent, some electrode production schemes employ a small amount of solvent, in an operation that takes place after the dry electrode composition has been formed, to “wet” the film during calendering, for instance. Such a process is also referred to herein as a “dry”Docket: 2020617PCTprocess, since this wetting step does not affect a binder processing step that is conducted under solvent-free conditions.Mixing and Processing the Binder

[0279] The dry process employed to prepare the electrode composition will typically target at least two objectives: blending some and often all the constituents, constituents that, in most cases, are provided in the form of loose (e.g., flowing or pourable) particles; and processing the binder in the presence of the CNS additive. In some embodiments, each of these two objectives is met by one or more mixing operations conducted under specific shear conditions, using suitable equipment.

[0280] A low shear mixing, for example, can be selected to distribute ingredients, as uniformly as possible, for example utilizing a roll mill. As used herein, the term “low shear mixing” refers to mixing conducted under conditions that are not sufficient or not substantially sufficient to fibrillize a fibrillizable binder. Relying on low shear mixing conditions can avoid excessive particle fragmentations, often a consideration for some electroactive materials.

[0281] In many embodiments, processing the binder in the presence of a CNS additive is conducted under high shear mixing. As used herein, the term “high shear” refers to shear conditions that are vigorous enough to deform (e.g., elongate, entangle) a binder to a degree sufficient to prepare a film electrode by a solvent-free technique. In the case of fibrillizable binders, “high shear” refers to conditions that are sufficient to fibrillize the binder.

[0282] Without wishing to be bound by a particular interpretation, it is believed that, in the presence of the CNS additive (typically multifunctional in character) and under high shear conditions, a binder polymer is deformed, becoming stretched out, elongated and entangled. Surface energy and / or the surface roughness attributes characterizing the CNSs can facilitate grabbing hold of the binder polymer and the two (CNSs and polymer) can become squished between electroactive particles, resulting in the binder polymer being stretched out. With CNS particles dispersed in the binder or on the surface of the binder, it is thought that the CNSs can hold together neighboring polymer domains. Other contributing factors include polymer-polymer interactions (which are expected to increase with increased polymerDocket: 2020617PCTelongations and / or with multi-directional shear forces), electroactive parti cl es-polymer binder interactions (which can relate to surface energy), and / or other factors.

[0283] At the same or substantially the same high shear conditions, these manifestations tend to become more pronounced when the binder employed is a fibrillizable binder. Surface and other properties of the CNS additive promote snagging the polymer here and there. With all particles moving under high shear mixing, the polymer becomes elongated, forming very long, very thin strands (having a high aspect ratio). Typically, these effects will be less pronounced with a non-fibrillizable binder processed at the same or substantially the same high shear conditions. Or, stated differently, a non-fibrillizable binder may require increased high shear conditions to obtain results approaching full fibrillization.

[0284] In addition to the processing contributions described above, CNSs can enhance electrical conductivity and, in many cases, can act as a mechanical reinforcement by enhancing the mechanical strength of the electrode via the contribution to its adhesion and cohesion.

[0285] In some situations, high shear mixing also can be relied upon to break particles into smaller fragments. The fragments resulting from comminuting larger particles can become uniformly spread throughout the electrode composition, thereby enhancing electrical conductivity and / or mechanical properties.

[0286] Specific shear values can depend on the scale of the operation, the materials involved, type of mixing equipment and / or other factors. Low or high mixing settings can be determined or optimized based on prior experience, routine experimentation, and so forth. In one example, routine experimentation is relied upon to find a shear regime that promotes the detangling CNS bundles.

[0287] Constituents can be combined in any order designed to obtain a mixture, preferably one that is well dispersed, e.g., with a uniform distribution of the constituents, in other words a mixture that is homogeneous. In one example, CNSs, fragments of CNSs and / or fractured CNTs are homogeneously dispersed on the surface of the electroactive material and the binder.

[0288] Binder processing (e.g., fibrillization) can be performed on any mixture or pre¬ mixture (pre-blend) which brings together the CNS additive and the binder.Docket: 2020617PCT

[0289] Suitabl e techniques that can be used or adapted to conduct the steps of mixing and / or binder processing, e.g., fibrillization, include mechanical agitation, shaking, stirring, etc., and can rely on equipment such as jet mills, tube mills, acoustic mixers, extruders, planetary mixers, other mixing devices, e.g., laboratory-scale mixers, equipment suitable for pilot-scale evaluations, for full-scale industrial manufacturing and so forth.

[0290] Stepwise sequences can employ one type of apparatus to conduct the first operation (e.g., preparing a pre-blend), and another type of apparatus in the subsequent operation (fibrillization, for instance). The same is true for shear and / or other mixing parameters.

[0291] In one embodiment, the CNSs are first combined with the binder using high shear equipment to process, e.g., fibrillize, the binder. In some cases, this high shear operation also breaks the additive particles into smaller CNS fragments and / or fractured CNTs and / or serves to detangle CNSs. The resulting mixture is then combined with the electroactive material (graphite in one example); use of low shear conditions during this step favors preserving particle size (of the electroactive material, for example).

[0292] In another embodiment, the CNS additive is first combined with the electroactive material in a pre-blending step conducted under low shear, for example, to obtain a uniform distribution of these two constituents. The binder is then added to this pre-blend and processed, e.g., fibnllized, using high shear conditions.

[0293] In a further embodiment, the electrochemical active material, the binder and the CNSs are all mixed (e.g., under low shear conditions); the mixture is then subjected to high shear conditions to process, e.g., fibrillate, the binder.

[0294] Other sequences are possible. For instance, the electroactive material can be first mixed with the binder, followed by the addition of the CNS additive and processing, e.g., fibrillization, under high shear conditions. Using a CNS-AAM composite can involve combining the composite with the binder and processing the binder.

[0295] Ingredients can be introduced incrementally. In one example, the CNS component is first combined with a portion of the total binder amount to be used. Electroactive material (e.g., NCM) is then added, followed by the addition of more binder.Docket: 2020617PCT

[0296] Processing, fibrillization, for example, can be conducted in one or more (two, three, four, five, six, etc.) mixing stages or pulses(s) that can last for a suitable period, e.g., within a range of from about 10 seconds to about 5 minutes, e.g., within a range of from about 30 seconds to about a minute, to about 90 seconds, to about 2 minutes, to about 2.5 minutes, to about 3 minutes, to about 4 minutes, to about 5 minutes; from about 1 minute to about 90 seconds, to about 2 minutes, to about 3 minutes, to about 4 minutes, to about 5 minutes; From about 90 seconds to about 3 minutes, to about 4 minute, to about 5 minutes; from about 2 minutes to about 3 minutes, to about 4 minutes, to about 5 minutes; from about 3 minutes to about 4 minutes, to about 5 minutes; from about 4 minutes to about 5 minutes. Different time intervals also can be employed. The duration of two, more or all pulses can be the same or different.

[0297] A pulse can be followed by a rest or a cool down period. Resting periods can be at ambient, e.g., room temperature. Cooling can be to a temperature below ambient, e.g., below room temperature, often at 0°C or below, for instance at a temperature within a range of about -5 to about 5°C.

[0298] The rest or cooling period can depend on temperatures reached during mixing, quantities handled, and so forth. In many cases, cooling will last for a few minutes, e.g., 10 minutes to half an hour or longer. Cooling periods can differ in duration and / or temperature conditions.

[0299] It is also possible to conduct low shear mixing in a stepwise fashion, using mixing pulses, followed by rest periods.

[0300] To illustrate, a binder-containing composition can be subjected to a high shear blending at about 25,000 RPM to about 10,000 RPM, optionally at about 18,000 RPM for half a minute, then cooled to a temperature at or below freezing, for 10 minutes, e.g., at about -10°C. A low shear mixing can be conducted at about 2,000 RPM to about 4,000 RPM, for 1 minute followed by a cool down for 10 minutes at about 0°C.

[0301] In one example, a pre-blend of a CNSs and electroactive material is prepared using an acoustic mixer e.g., for several minutes at 100 G force. The resulting blend is combined with the binder at fibrillization parameters, e.g., using a lab scale jet mill at the pressure rate of 100-90-90-10 psi. In another example, all components are mixed in a tube mill (such as an IKADocket: 2020617PCTTubeMill 100) at 25,000 rpm in a pulsed approach in which blending is alternated with rest periods, followed by a longer duration mixing operation. In a further example, powders are premixed in an acoustic mixer, then milled in a tube mill, e.g., an IKA TubeMill 100.

[0302] Mixing and / or processing, e.g., fibrillization, steps can be monitored by visual inspection, hand calendering, powder rheology, or another suitable technique. For instance, a small amount can be handled manually and sheared or passed through a hand calender. End points can be established based on experience, routine experimentation, visual inspection, and so forth. Whether these operations have been successful also can be determined by SEM, performance and / or other techniques typically conducted on the electrode product, e.g., an electrode film.

[0303] In an optional step, starting or intermediate materials and / or the resulting electrode composition, typically in the form of pellets, powders (often fluffy powders), or other forms of free flowing or loose particulate materials can be sieved to remove unwanted clumps.Details on the Resulting Electrode Composition

[0304] The electrode composition prepared using ingredients and techniques such as described above is typically in the form of a loose particulate material (such as free-flowing or pourable powders, flakes, pellets, beads, etc.). In specific embodiments, the composition includes an active electrode material, a CNS component and a “processed” binder. The CNSs and the active electrode material also can be present in a CNS-AAM composite and can be detected using techniques such as SEM.

[0305] Some electrode compositions, those prepared with a fibrillizable binder, for instance, will include a post fibrillization binder (also referred to herein as a “fibrillized binder”), often exhibiting fibrils of high aspect ratios. Compositions prepared with non fibrillizable binders will still present a binder that is “deformed” (elongated, entangled, etc.) but perhaps to a lesser extent than that observed with fibrillizable binders at the same or substantially the same fibrillization conditions. A processed, e.g., fibrillized, binder can be detected by EDS or other suitable techniques. Also, successful binder processing, e.g., fibrillization, often is reflected by the quality of the resulting electrode (electrode film, for example). In some cases, electrode compositions prepared with non- fibrillizable binders may include a post processing binder thatDocket: 2020617PCTis un-deformed (globular, rounded, spherical shaped, etc,); in such situations, due to their multifunctional character, CNSs can act as a binder, a conductive additive and as a mechanical reinforcement of the electrode,

[0306] In the electrode composition, the CNS component can include not only CNSs in their original form (as supplied), but also various CNS-derived species. Process operations and / or conditions employed to form the electrode composition can preserve the integrity of some or all the initial CNSs used, which will remain intact. In some cases, however, an initial CNS is broken into smaller CNS units, generating CNS fragments, for example. Except for their reduced sizes, CNS fragments generally share the properties of intact CNS and can be identified by electron microscopy and other techniques, as described above.

[0307] Also possible are changes in the initial nanostructure morphology of the CNS. For example, applied shear can break crosslinks between CNTs within a CNS to form CNTs that typically will be distributed in the composition or electrode as individual CNTs. It is found that structural features of branching and shared walls are retained for many of these CNTs, even after the crosslinks are removed. CNTs that are derived (generated) from CNSs and retain structural features of CNT branching and shared walls are referred to herein as "fractured” CNTs. These species are capable of imparting improved interconnectivity (between CNT units), resulting in better conductivity at lower concentrations.

[0308] In comparison to electrodes or electrode compositions that employ ordinary, individualized CNTs, e.g., in “as manufactured” form, fractured CNTs can readily be differentiated from ordinary carbon nanotubes through standard carbon nanotube analytical techniques, such as SEM, for example. It is further noted that not every CNT encountered needs to be branched and share common walls; rather it is a plurality of fractured CNTs, that, as a whole, possess these features.

[0309] Illustrative CNS fragment or fractured CNT sizes present in the product electrode compositions, electrodes and / or batteries can be within the range of from about 0.5 to about 20 pm, e.g., within the range of from about 0.5 to about 1 pm; from about 1 to about 5 pm; from about 5 to about 10 um; from about 10 to about 15 um; or from about 15 to about 20 pm. InDocket: 2020617PCTsome cases, reducing the fragment size too much, eg., to less than 0.5 gm, can compromise the electrical properties associated with utilizing CNSs.

[0310] Based on the total weight of the electrode composition, CNSs can be provided in an amount within a range of from about 0.1 to about 5 wt %, e.g., 0,3 to about 3 wt %. In one implementation, for instance, a CNS additive represents between 3 and 5 % by weight of the product electrode composition, such as, for instance, between 3 and: 3.5, 4 or 4.5 wt %; between 3.5 and: 4, 4.5 or 5 wt %; or from 4 and: 4.5 or 5 wt %; or from 4.5 and 5 wt%. In another implementation, a CNS additive is present in an amount within a range of from about 0.1 to: about 0.5, about 1.0, about 1.5, about 2.0, about 2.5; or from about 0.5 to: about 1.0, about 1.5, about 2.0, about 2.5, about 3; or from about 1.0 to: about 1.5, about 2.0, about 2.5, about 3.0; or from about 1.5 to: about 2.0, about 2.5, about 3.0; or from about 2.0 to: about 2.5, about 3.0; or from about 2.5 to about 3.0. Specific amounts within as well as outside these ranges can be selected.

[0311] In many cases, the amount of the CNS additive is equal to or, preferably, lower than the AC amount required to obtain the same or substantially the same electrode performance. In an alternative approach, reaching a performance level established with AC is expected to require lower amounts of the CN S additive, freeing extra volume for electroactive material.

[0312] In an illustrative LIB graphite anode composition, for example, the loading of the CN S additive is no greater than about 5 wt % and often no greater than about 3 wt %, for example no greater than 1 wt %. In specific examples, the loading of a multifunctional CN S additive is within the rage of from about 0.1 wt % to 1.0 wt %, such as, within the range of from about 0.1 to about 0.5, or from about 0.5 to about 1 wt %. Other examples employ a loading within the range of from about 1 to about 5 wt %, e.g., a loading of at least about 4.5, 4.0, 3.5, 3.0, 2.5, 2.0 or 1.5.

[0313] In an illustrative NCM cathode composition, the CNS additive is provided in amounts less than or equal to about 5 wt %, e.g., no greater than about 3 wt %, for example no greater than 1 wt %. In specific examples, the CNS loading is within the rage of from about 0.1 wt % to 1.0 wt %, such as, within the range of from about 0.1 to about 0.5, or from about 0.5 toDocket: 2020617PCTabout 1 wt %. Other exampl es employ a l oading within the range of from about 1 to about 5 wt %, e.g., a loading of at least about 4.5, 4.0, 3.5, 3.0, 2.5, 2.0 or 1.5.

[0314] Relative amounts of the CNS component to binder, e.g,, a fibrillizable binder, can be within a ratio of 5:1 to 0.1:10, e.g., from about 1:1 to 0.1:10, from 0.5:1 to 0.1:10; from 5:1 to 0.5:10, from 5:1 to 1:5; from 5:1 to 5:10 by weight. In specific cases, the weight ratio of the CNS additive to binder is 1:1.

[0315] In one embodiment, the electrode composition contains active electrode material in an amount of from about 92 wt % to about 99.8 wt %, binder in an amount of from about 0.1 to about 5 wt % and CNSs in an amount of from about 0.1 to about 5 wt %, e.g., to about 3 wt %.

[0316] The electrode composition, typically containing an electroactive material, processed binder, a CNS component (CNSs, fragments of CNSs and / or fractured CNTs) and, optionally, other ingredients, can be employed to form an anode, cathode or both an anode and a cathode, e.g., for assembly in a device such as a LIB. One, more, or all properties characterizing ultifunctional CNSs can be assessed in the product electrode composition, (in which the binder has been processed, e.g., fibrilhzed), in product electrodes (e.g., films), typically obtained by further processing the product electrode composition, assembled electrodes (in which the electrode composition or the product electrode (a film, for instance) has been applied to the suitable substrate) and / or batteries described herein. For example, the electrode can be tested for adhesion (assessing the attachment of the electrode film to a substrate), cohesion (assessing how well particles are bound together), electrode resistivity and / or other properties, by techniques known in the art.Films, Electrodes, Batteries

[0317] After mixing, binder processing, e.g., fibrillization, and optional sieving, the electrode composition (containing, at a minimum, an active electrode material, a CNS component (including CNSs, CNS fragments and / or fractured CNTs) and a post processing binder, e.g., a fibrillized binder) can be used to produce an electrode, employing techniques known in the art or developed in the future. For example, the electrode composition can be applied to a suitable support.Docket: 2020617PCT

[0318] In embodiments, the composition is first formed into a product electrode, e.g,, a film, which is then attached, e.g., laminated, to a conductive substrate. The film can be obtained by¬ calendering, an operation which can be conducted at or above room temperature, e.g., at a temperature similar or close to the polymer glass transition temperature. In a typical calendering operation, the composition is subjected to heat and pressure using an extruder. The softened material is passed through calendering rolls (vertical, for instance) to prepare a product electrode sheet or film.

[0319] In many embodiments, the film is free-standing, a property that can be described using a 100-200pm thick film that stands on its own, with no part of the film being in contact with any type of support, e.g., a substrate.

[0320] A desired film thickness can be obtained by adjusting the gap between the rolls, and, in some situations, other process parameters.

[0321] The roll temperature can be, for example, from about room temperature (20°C) to about 200°C, High roll temperatures may result in a thinner free-standing film on the first pass, whereas the opposite happens at lower temperature. Roll speed can vary. In illustrative examples, the roll speed is set from about 0.17 meters per minute (m / min) to about 1.3 m / min. A slower roll speed tends to produce a thinner free-standing film on the first pass compared to a faster roll speed. The hydraulic pressure employed can be within a range of from about 1,000 psi to about 7,000. Again, a higher pressure may result in a thinner free-standing film on the first pass compared to the thicker films obtained at a lower pressure.

[0322] Additional passes through the roll mill may be employed, reducing the film thickness until the desired thickness and loading are reached. In specific implementations, the film thickness is within a range of form about 30 pm to about 300 pm, e.g., from about 50 to about 200 pm, from about 100 pm to about 150 pm. Also possible are film thicknesses within a range of from 50 to 100, 50 to 150, 50 to 200, 50 to 250; or from 100 to 150, 100 to 200, 100 to 250, 100 to 300; or from 150 to 200, 150 to 250, 150 to 300; or from 200 to 250, from 200 to 300; or from 250 to 300 pm. Desired loadings may be about 10 mg / cm2to about 50 mg / cm2.

[0323] In an optional operation, the film is thermally activated, e.g., to soften the binder and prepare the electrode product for being applied to a substrate. In the laboratory, this operationDocket: 2020617PCTcan be conducted using a hot plate, at 100° centigrade (C), for instance. Approaches for larger scale processes include temperature-controlled roll to roll calenders, convective and / or microwave driers, and so forth.

[0324] The film (typically free-standing and containing active electrode material, a CNS component (composed of CNSs, fragments of CNSs and / or fractured CNTs) and a post processing, e.g., fibrillized, binder) can be applied to a conductive substrate or support (an aluminum or copper current collector, for example). In one embodiment, the film is laminated to a carbon-coated copper foil by calendering the two together, using, for instance a horizontal hot roller at a suitable roll temperature, roll speed and hydraulic pressure.

[0325] The roll temperature can be within the range of from about 50 to about 150°C. Temperatures that are too high can increase blister formation and poor adhesion, while temperatures that are too low can hamper adhesion.

[0326] Roll speed may be from about 0.17 m / min to about 1.3 m / min, e.g., about 0.5 m / min, while the hydraulic pressure may be set from about 500 psi to about 2,000 psi. Other settings can be employed. The pressure can be optimized to be high enough to promote adhesion to the substrate without altering loading, porosity or other properties. In some implementations, lamination is performed before setting the final thickness and / or porosity of the film electrode.

[0327] The formation of the film and its application to the substrate can be conducted in a single step in some cases. For instance, a powder electrode composition (containing processed, e.g., fibrillized, binder, and a substrate foil can be fed together through calendaring rolls under conditions suitable to produce a laminate in which the composition is pressed to film thickness and adhered to the foil. In this approach, forming a self-standing film is obviated.

[0328] The laminated structure can be shaped and / or sized for specific applications, such as electrochemical cells, for instance, LIBs, e.g., rechargeable LIBs, and so forth.

[0329] Electrodes prepared as described herein can be incorporated into a lithium-ion battery according to methods known in the art, such as, for example, those described in " Lithium Ion Batteries Fundamentals and Applications", by Yuping Wu, CRC press, (2015). In specific implementations, the batteries are com types such as, for example, 2032 coin-cells, 18650 cylindrical cells, pouch cells, or others.Docket: 2020617PCT

[0330] An illustrative dry processed electrode includes an active material in an amount of from about 92 wt % to about 99.8 wt %, binder in an amount of from about 0.1 wt % to about 5 wt % and a CNS component (CNSs, fragments of CNSs and / or fractured ( / NTs) in an amount of from about 0.1 wt % to about 5 and in many cases to about 3 wt %.

[0331] A LIB can include an anode prepared by a dry process that contains a CNS component (CNSs, fragments of CNSs and / or fractured CNTs), typically acting as a multifunctional additive and provided, m many cases, m an amount no greater than 5 wt %; a graphite (natural graphite, artificial graphite or blends of both, commercially available types of graphite such as MCMB, MCF, VGCF, M / XG, etc.) active anode material; and a processed binder which, in many cases, displays fibrils. As described above, the graphite active material can be present in an amount of at least 80 wt %, such as at least 85 or at least 90 or at least 95 wt %, e.g., within a range from about 80 to about 99 or even higher, e.g., up to 99.8 wt %.

[0332] A battery cathode prepared using a solvent- free process can contains a processed binder (e.g., in the form of fibrils); a CNS component (CNSs, fragments of CNSs and / or fractured CNTs), in an amount no greater than 5 wt %; and electroactive material (e.g., NCM or NCA) in an amount of at least 90% by weight, e.g., greater than 95% by weight, relative to the total weight of the electrode composition, e.g., an amount ranging from 90% to 99%, or even higher, e.g., 99.8 % by weight, relative to the total weight of the electrode composition.

[0333] The second (opposite) electrode in the battery also can be prepared using a solvent- free process such as described herein, for instance. In one implementation, both electrodes in the battery contain a CN S component.

[0334] It is also possible to prepare the second electrode by a conventional dry process (using AC, for instance), by a slurry or by another non-dry technique.

[0335] In addition to the two electrodes, the typical LIB comprises a suitable electrolyte. Examples include, for instance, ethylene carbonate-dimethyl carbonate-ethylmethyl carbonate (EC-DMC-EMC), vinylene carbonate (VC), LiPFe; ethylene carbonate-diethlycarbonate (EC-DEC, LiPFe; or (EC-DMC), LiPF6. Furthermore, electrolyte composition may contain special additives known to enhance the performance of SiOxor silicon comprising anodes, for example fluorinated carbonates, such as fluoroethylene carbonate and others. In the laboratory, aDocket: 2020617PCTseparator that absorbs electrolyte and prevents electrical contact between electrodes, while allowing diffusion of Li ions, can be a suitable glass fiber micro filter (for example, Whatman GF / A). Membrane separators made of polypropylene / polyethylene (for example, Celgard 2300) also can be used in some cases.Evaluation Techniques

[0336] The composition or morphology of films, electrodes and / or batteries described herein can be characterized by various techniques. Examples include but are not limited to electron microscopy, e.g., TEM, SEM, X-ray tomography, Raman spectrometry, and other suitable qualitative or quantitative analytical methods. Binder strings (tendrils) connecting active material particles and / or particles containing CNSs can be visualized using EDS. In one example, SEM data for graphite electrodes prepared by a dry process using the multifunctional CNS additive described herein revealed the presence of ribbon-like binder fibrils, indicating effective fibrillization.

[0337] In many cases, dry-processed electrodes or films can be distinguished from slurry¬ based products by very low or undetectable levels of solvent or solvent residue. The presence or absence of solvent or solvent residues can be evaluated by weight testing. This involves drying the wet-casted electrode until electrode weight reaches the value theoretically calculated based on known solids loading of the slurry, or until electrode weight stabilizes and does not change for minimum of 3 min. In the case of an electrode produced entirely in the absence of solvent, the weight remains the same over the evaluation period. Or, stated differently, the weight of the just prepared electrode (before any drying operation) is the same as or within 1 wt % of the theoretical weight (i.e., the weight obtained by adding together the weights of the individual ingredients provided in the process).

[0338] Another approach that could be employed to detect a solvent (e.g., NMP) relies on attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy (FTIR-ATR), in conjunction with gas chromatography (GC).

[0339] A substantially uniform binder distribution, without binder migration towards a film surface, is yet another feature that often characterizes an electrode or electrode product, e.g.,Docket: 2020617PCTfilm, prepared by a solvent- free process. In some cases, thick electrodes (e.g,, at least 100 microns) may be indicative of electrodes made by a solvent-free technique.

[0340] While dry processed films or electrodes will contain binder ribbons, strings, tendrils etc. (detected by EDS, for example), this is not the case with films or electrodes prepared by wet techniques.

[0341] Free-standing films prepared using CNSs in a solvent-free process or in a solvent-free binder processing step are expected to have good mechanical properties. One mechanical evaluation technique that can be relied upon relates to tensile strength testing, which can be conducted using a Mecmesin MultiTest 2.5-dV tester equipped with the advanced force gauge AFG 10N. Other suitable techniques can be employed to measure the tensile strength of the film, as known in the art. In one example, a graphite anode film is expected to have a tensile strength of at least lOOkPa, while the tensile strength of a NCM cathode film or a Si-contaming anode film is expected to be at least 50kPa. In another example, the free-standing film has a tensile strength of at least 0.1 MPa and a thickness ranging from 30 pm to 500 pm. In many cases, the mechanical performance of the film was at least as good as that of a comparative film fabricated using AC.

[0342] Good mechanical properties also are expected for electrodes prepared utilizing a CNS additive in a process such as described herein. Mechanical evaluation techniques that can be relied upon include peeling testing (e.g., 90°, 180°, T-peel, various fixtures), pull testing, and bending testing (mandrel experiments), to name a few.

[0343] Flexibility properties characterizing the electrode, (its ability to resist cracking) can be measured by visual inspection upon bending a film by hand or using a Mandrel bend tester. In specific implementations, the electrode is evaluated and expected to pass a 10 mm diameter mandrel bar test without visible cracking to the unaided eye. In an illustration, the electrode was found to pass a bending test using a pen of 8 mm diameter as a rod.

[0344] In many cases, the mechanical performance of electrodes prepared according to embodiments of the disclosure was at least as good as that of a comparative electrode fabricated using AC.Docket: 2020617PCT

[0345] Electrode performance can be tested by procedures known in the art, or techniques adapted or developed in the future. Suitable techniques include, for instance, in-plane and thru plane electrode conductivity, electrochemical impedance spectroscopy (EIS), constant current charge-discharge, hybrid pulse power capability (HPPC), cycling.

[0346] In many cases, electrodes prepared by a solvent-free process, using a CNS additive, perform at least as well and often better (as measured by in-plane resistivity, initial capacity, or first cycle efficiency, for example) relative to a comparative (also referred to herein as a “reference”) electrode containing the same amounts of active electrode material (e.g., graphite), binder, and a conventional fibillization agent such as AC Or, the amounts of multifunctional additive required to reach the performance obtained with AC will typically be lower for electrodes fabricated according to embodiments described herein.

[0347] In one illustration, a dry process graphite anode prepared using CNSs at loadings no higher than about 1 wt %, displayed at least as good a performance (measured by m-plane resistivity, rate capability, 1stcycle efficiency) as a comparative electrode containing higher amounts (e.g., 5 wt %) of AC.

[0348] Without wishing to be bound by a specific interpretation, it is believed that using a CNS additive such as described herein can produce ribbon-like binder strands or fibrils that can be long enough to wrap around and hold together particles of the electroactive material. Thus, even at relatively low levels, CNSs appear capable of processing, e.g., fibrillating, the binder, generating effective conductive networks in electrodes, while also contributing to desirable mechanical properties.

[0349] Compositions and methods described herein also can be used (e.g., incorporated) and / or adapted to the manufacture of other energy storage devices, such as, primary alkaline batteries, lithium-metal batteries, nickel metal hydride batteries, sodium batteries, lithium sulfur batteries, metal-air batteries, solid state batteries (SSB) and supercapacitors, to name a few. Methods of making such devices are known in the art and are described, for example, in " Battery Reference Book", by TR Crompton, Newness (2000).

[0350] The disclosure is further illustrated by the following non-limited examples.ExamplesDocket: 2020617PCTMaterials and Methods

[0351] The materials used for the solvent-free electrode process and formulations included: Graphite BTR 918-2A from Targray as active material for graphite anode; NCM111 from Toda and NCM622 from Targray as active material for NCM cathode; a combination of Graphite SLC-1506 T from Superior Graphite and Si-C composite SCC55 from Group 14 as active materials for Si-containing anode; carbon nanostructures (“CNS”) from Cabot Corporation as a multifunctional additive; and standard activated carbon (AC) of surface area of 1500 cm2 / g as standard fibnllizing additive. The fibrillizable binder was polytetrafluorethylene (PTFE) Teflon™ 601X by Chemours obtained from Fluorogistx; the same type of binder was used to fabricate graphite anodes and NCM cathodes. Another binder used in combination with PTFE for Si-containing anode was Polyvinylidene fluoride (PVDF) IISV 900 produced by Arkema.

[0352] CNSs used as multifunctional carbon additives for dry electrodes processing are shown m Table 1. CNSl is the pristine CNS flake. CNS2 is the pelletized form of CNSl, encapsulated with a polymer binder. CNS3 is a milled version of CNS2, produced using a mechanical grinding machine (Model: FW177, from Tianjing Tai Si Te Instrument Co., Ltd.) operating at 50Hz, 1200W, and 24,000 rpm. CNS4 and CNS5 are purified versions of CNS2 of D50~20pm. The particle size distribution was determined using a laser particle sizer with the powder suspended in DI water with being sonicated for 2mm (Model Topsizer, Zhuhai OMEC Instruments Co., Ltd.).Table 1Additive D10 (pm) D50(pm) D90 (pm) BET (m2 / g) CNSl 22.4 48.4 99.4 269.2CNS2 18.3 46.3 105 287.4CNS3 9 20.2 36.7 256.7CNS4 9.33 19.8 35.3 225.2CNS5 9.14 20.3 36.3 383.5

[0353] Generally, dry-process anode electrodes were prepared in several stages. In a first step (SI) the electrode components were combined and mixed under conditions suitable to blend powders uniformly and fibrillate the binder (e.g., by low and high shear mixing). The second step (S2) involved passing the powder blend from SI through a vertical calender pre-set to theDocket: 2020617PCTappropriate gap based on the desired film thickness. The free-standing films obtained from S2 were laminated onto a current collector in a third step (S3).

[0354] A similar sequence of steps was followed in preparing cathode electrodes.

[0355] The thickness of the solvent-free electrodes was measured using a manual drop gauge with the flat gauging contact head of 7,14 mm diameter, A manual die cutter was used to punch discs of diameter of 15 mm for cathode and 16 mm for anode.

[0356] The tensile strength of the solvent-free films was measured using Mecmesin MultiTest 2.5-dV tester equipped with the advanced force gauge AFG 10N, Testing was performed for the equivalent films series.

[0357] The sheet resistance of the solvent-free electrodes was measured with a Signatone Pro4-4400 commercial system (SP4 probe head connected to the rear of a Keithley 2410-C source meter). Measurements were performed in a four-wire configuration mode. The reported values were normalized by the electrode thickness and reported as electrode resistivity in Ohm- cm.Example 1 - Graphite anode

[0358] The four graphite anode formulations studied are listed m Table 2, below.Table 2Electrode Active material Carbon Additive Binder Film quality A-l 94% Graphite 1% CNS1 (as is) 5% P TIT PassA-2 94% Graphite 1% CNS1 (processed) 5% PTFE Pass Reference- 1 90% Graphite 5% AC 5% PTFE Pass Control- 1 95% Graphite None 5% PTFE Fail

[0359] Electrodes A-l, A-2 and Control-! were prepared following a 3-step protocol. In SI, all electrode components were blended using an IK A Tube Mill 100, all the electrode components being processed together at 25,000 rpm, 6 x 15 second blending pulses with 45 second rests in-between, followed by 2 minutes of straight blending. Here, the CNS materialDocket: 2020617PCTwas used in a flake form (CNS 1 “as is”) m Formulation A- 1 and was pre-milled version of CNS 1 using IKA Tube Mill 100 at 25,000 rpm, 5 x 3-minute blending periods with 1 -minute rests inbetween before being blended with other components in formulation A-2.

[0360] In S2, the powder blend obtained in SI was passed through a vertical calender at room temperature to obtain free-standing films having a thickness between 80 and 300 m.

[0361] In S3, the tree-standing electrode films were thermally activated on a hot plate set to 100 °C, then laminated on the carbon-coated, 9-pm thick Copper foil (MTI Corporation) by calendaring them together using a horizontal hot-roller calender pre-heated to 80°C.

[0362] Reference-1 electrode was prepared following a 3-step protocol where a Jet mill was used to fibrillize the binder in SI. In SI, the pre-blended electrode components were passed through the lab-scale jet mill at the pressure rate of 100-90-90-10 psi. Steps S2 and S3 were the same as for electrodes A-l, A-2 and Control- 1.

[0363] Photos of the electrode prepared using formulation A-l and Control-1 are shown in Fig. 4A and Fig. 4B, respectively. As opposed to the fibrillizer-free film, addition of 1% of CNS to the formulation made possible the fabrication of a flexible free-standing film.

[0364] SEM photographs of cross-sections of electrodes prepared using formulation A-l are shown in FIGS. 5A and 5B, while FIG. 5C is a SEM of a control electrode that used no fibrillating agent and contained 95 wt. % graphite and 5 wt. % PTFE / Xrrows in FIG. 5B point at CNS ribbons wrapped around the active material particles.

[0365] Whereas fibrils of the binder can be visualized in the formulation with CNS (see FIG. 5A), no fibrils are seen in the fibrillizer-free formulation (FIG. 5C). These observations indicate that CNS can function as a binder fibrillizing additive. In addition, FIG. 5B depicts ribbons of CNS material that are longer than the diameter of active particles and can be considered as a reinforcing additive for improved strength and flexibility of the electrode films. This type of morphology is also expected to improve long-range conductivity across the electrode.

[0366] FIG. 6 A presents in-plane electrode resistivity of dry processed graphite anodes A-1, A-2 and Reference- 1. Despite a CNS loading that was 5 times lower than the AC loading, CNSs brought about comparable resistivity in the lower data distribution range for the anode A-Docket: 2020617PCT1. By using pre-milled CNS of improved di persibility. Anode A- 2 showed improved in-plane resistivity which was superior to the Reference- 1, a state-of-art dry anode containing 5% AC. The values and distribution are expected to be improved further upon optimizing the CNS dispersing process.

[0367] FIG. 6B presents rate capability of dry processed anode A-l, containing 1 wt % CNS1 (21 mg / cm2or 7.4 mAh / cm2) and a comparative anode (Reference-1) containing 5 wt % AC (26 mg / cm2or 9.2 mAh / cm2), tested in half coin-cells against Li metal. The insert in FIG.6B shows 1st cycle efficiency. The A-l formulation exhibited better rate capability and 1st cycle efficiency than the Reference-1 formulation. Based on the given datapomts available for extra thick electrodes (20+ mg / cm2of active material loading), CNSs appear to deliver higher capacity at faster rates and thus better power density for the cell compared to traditional AC. Example 2 NCM111 Cathode

[0368] The four NCM111 cathode formulations studied are listed in Table 3 below.Table 3Electrode Active material Carbon Additive Binder Film quality C-l 94% NCM111 1% CNS1 5% PTFE Pass Rereference- 94%NCM111 1% AC 5% PTFE Pass2.1Reference- 9O%NCM1I1 5% AC 5% PTFE Pass22Control-2 95% NCM111 None 5% PTFE Fail

[0369] Cathode formulations and test electrodes were prepared as follows. In SI, the CNS material was first processed in an IKA Tube Mill 100 at 25,000 rpm, 5 x 3-minute blending periods with 1 -minute rests in-between and then mixed with other electrode components following a two-stage operation. In more detail, the first stage of SI for formulations C-l, Rereference-2.1, and Reference-2.2 was performed to prepare a uniform distribution of powder components in the blend and included a 5-minute pre-blending of a carbon additive (AC or CNSs) and electrode active material in the acoustic mixer at 100% intensity and auto frequency,Docket: 2020617PCTfollowed by the addition of the polymer binder and blending at the same settings for 1 more minute. For the Control-2 formulation which contains no carbon additive, only 1-min acoustic mixing of active material and polymer was applied. For all cathode formulations, the second stage of SI was performed using a IKA Tube Mill 100, where the pre-blended electrode components were processed at 25,000 rpm, 6 x 15 second blending pulses with 45 second rests in-between, followed by 2 minutes of straight blending. Conditions to fabricate a free-standing film (S2) and electrode (S3) were the same as for anode formulation A-l.

[0370] FIG. 7 presents tensile strength of dry processed films C-l, Rereference-2.1, and Reference-2.2. C-l formulation with 1% CNS additive showed the highest tensile strength which was 4- and 3-times better than for the Rereference-2.1 and Reference-2.2 cathodes containing AC as a standard fibrillizing additive, respectively. The Control-2 cathode film was too week to perform the test confirming a need for a binder fibrillizing additive for effective dry¬ electrode processing.

[0371] FIG. 8 presents in-plane electrode resistivity of dry processed NCM cathode films listed in Table 3. Similarly to anodes, the presence of 1 wt.% of pre-milled CNSs (C-l) showed the benefit of the lowest electrode resistivity, greatly improved over the Control, Rereference-2.1, and Reference-2.2 formulations containing 0, 1, and 5 wt.% of standard carbon additive, respectively.Example 3 - Si-containing anode by mixing method (SI)

[0372] The three Graphite / Si-C dry anode formulations studied are listed in Table 4 below. Table 4Carbon Powder Blend Film Electrode Active material Additive Processing quality Bindermethod in S 1D-l 84% Graphite, 10% 1% CNS1 2% PTFE, Method 1 Pass Si-C composite 3% PVDFD-2 84% Graphite, 10% 1% CNS1 2% PTFE, Method 2 Fail Si-C composite 3% PVDFD-3 84% Graphite, 10% 1% CNS1 2% PTFE, Method 3 Fail Si-C composite 3% PVDFDocket: 2020617PCT

[0373] Si-containing anode formulations and test free-standing films were prepared in two stages. As shown in Table 4, in the first step (SI), dry powder blends for the electrodes D-l, D- 2, and D-3 were prepared using 3 different mixing protocols.

[0374] Method 1: CNS1 powder was milled in a Retsch ball mill with 99% IPA to form a paste-like consistency using zirconium media. The mixture was milled at 200 rpm for 60 minutes, with a cycle of 10 minutes on and 5 minutes off. Half of the graphite was then added to the CNS paste and ball milled for 30 minutes, with a stop at 15 minutes to scrape the walls and check the paste quality. The paste was dried in an oven at 100°C for 18 hours. The remaining graphite, Si-C composite, and PVDF are then added and milled for 25 minutes. This was followed by adding PTFE and continued milling for an additional 5 minutes. The mixture was then blended in a Magic Bullet for 6 minutes in 30-second increments with 3-minute rests between increments.

[0375] Method 2: CNS1 powder was milled in an 1KA mill for 60 minutes at 25,000 rpm, with 3-minute increments and 1 -minute rests. Graphite and the Si-C composite were mixed in a Magic Bullet for 1 minute. The combined active material with Graphite and Si-C composite and CNSs were then mixed in an acoustic mixer for 20 minutes followed by the addition of PVDF and PTFE and mixing for another 10 minutes. All materials were then mixed in a Thinky cup for 2 minutes in 15-second increments at 2,000 rpm, with 5-minute cooling periods. Finally, the mixture was blended in a Magic Bullet for 6 minutes in 30-second increments with 3-minute rests.

[0376] Method 3: Similarly to Method 1, CNS1 powder was milled in a Retsch ball mill with 99% IPA to form a paste-like consistency using zirconium media. The mixture was milled at 200 rpm for 60 minutes, with a cycle of 10 minutes on and 5 minutes off. Unlike the protocol in Method 1, graphite, Si-C composite and PVDF were added all together and milled for 25 minutes followed by the addition of PTFE and milling for 5 more minutes. The mixture was dried overnight in an oven at 100°C. Then, the dry mixture was blended in a Magic Bullet for 6 minutes in 30-second increments with 3-minute rests between increments.Docket: 2020617PCT

[0377] In the second step (S2), the fibnlized powder blend obtained in SI was passed through a vertical calender at 50 C° to obtain free-standing films having a thickness between 120 and 300 pm.

[0378] The quality of the dry film made with Method 1 represented an improvement over the ones made with Method 2 and 3 as indicated by the " Pass" or " Fail" labels in Table 4.

[0379] The tensile strength and elastic modulus of the D-l and D-2 dry anode films are presented in FIG. 9. As shown, the tensile strength of the D-l improved by approximately 65% compared to D-2 while the elastic modulus of films remained comparable. These results suggest that Method 1 is more suitable for producing stronger films.Example 4 - Si-Containing Anode by CNS Type

[0380] The four Graphite / Si-C dry anode formulations studied in this example are listed in the Table 5, below. The carbon additives employed were the different types of CNS from Table 1, All dry process anodes were calendered at active materials loading of about 19 mg / cm2and electrode density of about 1,7 cm3 / g.Table 5Electrode Active material Gabon Additive Binder Film quality E-l 84% Graphite, 10% Si-C composite 1% CNS2 2% PTFE, Pass3% PVDFE-2 84% Graphite, 10% Si-C composite 1% CNS3 2% PTFE, Pass3% PVDFE-3 84% Graphite, 10% Si-C composite 1% CNS4 2% PTFE, Pass3% PVDFE-4 84% Graphite, 10% Si-C composite 1% CNS5 2% PTFE, Pass3% PVDF

[0381] The Si-containing anodes in this example (E-l through E-4) were fabricated following the 3 -steps procedure.Docket: 2020617PCT

[0382] In more details, in SI and S2, the free-standing anode films were prepared using the powder mixing protocol of Method 1 and film calendering approach described in Example 3.

[0383] In S3, electrodes were prepared by laminating the dry free-standing films onto a carbon-coated, 11 -pm thick copper foil (from MTI Corporation). This was done by calendaring them together using a vertical hot-roller calender pre-heated to 80°C. Additionally, the electrodes were pressed for 2 minutes between preheated 100°C, 12x12 meh metal sheets with a pressure of 40,000 pound-force. As shown in FIG. 10, the dry silicon-contaimng anode films E-2, E-3, and E-4 prepared with CNSs of Dso of about 20pm displayed enhanced tensile strength compared to the anode film E-l made with pelletized CNS material of larger Dso size. This suggests that there are strengthened interactions between the binder and presumably more unbundled CNSs of Dso as low as about 20pm for improved reinforcement and film quality. The comparison of E-3 and E-4 prepared with CNSs modified by different methods further suggested that less graphitic surface allows formation of relatively stronger, better quality anode films. Additionally, the comparison of E-2, E-3, and E-4, prepared with CNSs of varying surface areas, suggests that a larger BET surface area enhances the strength of the film formation.

[0384] FIG. 11 presents the in-plane electrode resistivity of the selected dry anodes laminated on the current collector. As seen in FIG. 11, the electrode with CNSs of lower Dso (E-2, E-3, and E-4), regardless of the purification method and surface chemistry, also demonstrated improved conductivity, which is another indicator of a benefit of the selected particle size of CNSs (believed to lead to improved distribution of CNS particles throughout the electrode in addition to enhanced interactions with binder and fibrillization properties). An improvement in electrode resistivity (in other words, electrode conductivity’) would improve the battery performance. SEM images presented in FIG. 13A for the Electrode E-4 evidence no significant CNS aggregation within the films prepared with CNS 5. SEM analysis also provided insights into the binder fibrillization level, a large number of fibrils appeared to be wrapping around active electrode materials and / or carbon as shown in the FIG.13B.Example 6 - Electrochemical cell assembly

[0385] The electrochemical performance of anodes El to E4 from Table 5 was tested in 2032 half and full coin cells. For testing in half-coin cells, fifteen-millimeter in diameter discsDocket: 2020617PCTwere punched and dried at 100°C under vacuum for a minimum of 4 hours. Discs were calendered at the desired electrode density with a manual roll press and assembled into 2032 coin-cells in an argon-filled glove box (M-Braun) for testing against Lithium metal foil. For testing in full-coin cells, sixteen-millimeter in diameter discs were punched and dried at 100°C under vacuum for a minimum of 4 hours. Discs were calendered at the desired electrode density with a manual roll press and assembled into 2032 com-cells in an argon-filled glove box (M-Braun) for testing against slurry-processed NCM622 cathodes which contained 1.5% CB, 1.5% PVDF, 97% NCM622, at anodic access of 1.2, measured as a negative to positive electrodes capacity ratio (N / P). 2325 Celgard film was used as the separator. The IM lithium hexafluorophosphate (LiPFs) in ethylene carbonate-dimethyl carbonate-ethyl methyl carbonate (EC-DMC-EMC, 1:1:1 by wt.) with 1 wt.% vinylene carbonate (VC) from E-Lyte was used as electrolyte. The room temperature (25 °C) rate performance of the full coin cells was measured by first forming them by four C / 20-D / 20 charge-discharge cycles, then charging and discharging them at each rate for four cycles at C / 10, C / 5, C / 3, C / 2, 1C, and 2C, respectively. Cycling performance testing of the full cells was carried out at 25°C using C / 3 charge and C / 3 discharge rate after C-rate capability test. The cells comprising cathode C3 underwent additional formation cycle at C / 20 charge and C / 20 discharge before cycling test.Example 7 - Preparation of CNS-SiOx Particles

[0386] This example illustrates the fabrication of CNS-AAM composite powder by a spray drying method, which is suitable for LiB anode composition.

[0387] An amount of 35.6 g water was combined with 19.5 g 5 wt. % polyvinyl alcohol (Mowiol® 4-98 with MW - 27,00 g / moi available from Sigma-Aldrich) and mixed using an IKA homogenizer at 1000 rpm. 37.5 g of aqueous 0.8 wt% CNS slurry' (available from Cabot Corporation under Enermax 708A name) was slowly added; the homogenizer speed was increased to 8000 rpm. After 15 min mixing, the speed of the homogenizer was reduced to 3000 rpm and 36.75 g SiOx (KSC-1265 available from ShinEtsu Chemical Co) was added. Afterwards, the suspension was mixed for 15 min at 8000 rpm. Finally, the homogenizer speed was reduced to 2000 rpm and 1.5 g of acidified 5 wt% aq. solution of gluteraldehide (Aldrich) was added. The resulting mixture had the following composition SiOx: CNS: PVA: gluteraldehyde: water = 36.75: 0.3: 0,975: 0,075: 61.9. After 5 min of mixing, the suspensionDocket: 2020617PCTwas fed to a Buchi spray dryer operating at the inlet temperature of 200 C and outl et temperature of 130°C. In this example, the glutaraldehyde serves as a crosslinking agent for PVA chains, which occurs at the elevated temperature of the spray drying. The yield of the CNS-SiOx composite powder was about 91%. FIG. 12 the results of dynamic light scatting measurements for suspension of SiOx (as-is) and the obtained SiOx-CNS composite. The results showed the size of the SiOx-CNS composite particles slightly increased with the spray drying process, largely remaining, however, below 20 microns, an important consideration for the LiB electrode fabrication. Optionally, if required, the size of the composite particles can be further reduced by the dry milling methods well known in the art.Example 8 - NCM622 Cathode Comprising CNS and / or CNT

[0388] Cathode dry-processed free-standing films were prepared in the similar manner as described for the cathode formulation C-l in Example 2, except that there was a difference in time and intensity. In more detail, the first stage of SI was performed to prepare a uniform distribution of powder components in the blend and included 10-minutes of pre-blending of a carbon additive and electrode active material in the acoustic mixer at 90% intensity and auto frequency, followed by the addition of the polymer and blending at the same settings for 20 more minutes. The second stage involving fibrillating the blend was further processed using IKA Tube Mill 100 for 15 sec at 25,000 rpm for 6 cycles and 3 min at 5000 rpm for 1 cycle. In S2, the powder blend obtained in SI was passed through a vertical calender at 100 °C to obtain free-standing films. The conductive additive used in this example wasCNS5, or CNT5, or a combination of CNS5 and CNT5 processed together in SI at different ratios.

[0389] The formulations employed (labeled Fl through F4) are listed in Table 6, below. All the electrode films were prepared with a carbon additive (CNS only, CNT only, or combinations of CNS and CNT, blended at different CNS / CNT ratios) at a total carbon loading of 1 wt.%. The NCM622 loading was 96 wt. % and the PTFE loading was 3 wt. %.Docket: 2020617PCTTable 6Average Dry Formulation Active material Carbon additive CNS / CNT Binder FilmID ratio Thickness (um)Fl 96% NCM622 1% CNS5 100:0 3% PTFE 110.5F2 96% NCM622 1% CNS5 / CNT5 10:90 3% PTFE 111.5F3 96% NCM622 1% CNS5 / CNT5 30:70 3% PTFE 114F4 96% NCM622 1% CNT5 0:100 3% PTFE 112

[0390] FIG. 14 compares the tensile strength of dry cathode films prepared with formulation FT (an NCM622 electrode containing only CMS) to those with formulations F2 and F3 (CNS / CNT blends at two different ratios) and formulation F4 (containing only CNT). As shown in FIG. 14, the dry electrode films made with CNS / CN T blends (F2 and F3) exhibited higher tensile strength than the CNT-only film (F4) and demonstrated improved flexibility compared to one with CNS-only film (Fl), as reflected by their lower elastic modulus. The dry films incorporating CNS / CNT blends effectively combine the advantages of both CNS and CNT, achieving an optimized balance between mechanical strength and flexibility.Example 9 - Electrochemical Performance

[0391] A series of free-standing films were laminated on the carbon-coated, 17-pm thick Al foil by calendaring them together through a vertical calender at 110 °C to obtain the positive electrode (G1-G4).

[0392] The electrode formulations employed, and characteristics of the resulting cathodes are listed m Table 7 below.Table 7Electrode Formulation Active material Electrode ID loading density [mg / cm'] [g / cm3] G1 96% NCM622, 1% CNS5, 3% PTFE 22.2 3.8G2 96% NCM622, 0.1 % CNS5, 0.9% CNT5, 3% PTFE 22.7 3.8G3 96%NCM622, 0.3% CNS5, 0.7% CNT5, 3% PTFE 22.5 3.8G4 96% NCM622, 1% CNT5, 3% PTFE 24.6 3.6Docket: 2020617PCT

[0393] The cathodes from Table 7 were tested in 2032 full coin cells. Fifteen-millimeter in diameter discs were punched for com-cell preparation and dried at 100°C under vacuum for a minimum of 4 hours. Discs were calendered at the desired electrode density with a manual roll press and assembled into 2032 com-cells m an argon-filled glove box (M-Braun) for testing against slurry-processed graphite anodes which contained 3% CB, 5% CMC-SBR, 92% natural graphite, at anodic access of 1.2, measured as a negative to positive electrodes capacity ratio (N / P). 2325 Celgard film were used as separators. The I M Lithium hexafluorophosphate (LiPFs) in ethylene carbonate-dimethyl carbonate-ethyl methyl carbonate (EC-DMC-EMC, 1:1:1 by wt.) with I wt.% vinylene carbonate (VC) from E-Lyte was used as electrolyte. Room temperature (25 °C) rate performance of the full coin cells was measured by first forming them by four C / 20-D / 20 charge-discharge cycles, then charging and discharging them at each rate for four cycles at C / 10, C / 5, C / 3, C / 2, 1C, and 2C, respectively. Reported capacities are normalized in mAh / g of active cathode mass. Cycling performance testing was carried out at 25°C using C / 3 charge and C / 3 discharge rate.

[0394] FIG. 15 compares the rate performance of four electrodes (G1-G4) under increasing charge-discharge rates from C / 10 to 1C. Among these, G2 and G3 are the electrodes containing CNS / CNT blends, which maintain higher discharge capacities and better rate retention than the single-component electrodes (Gl and G4), especially at higher rates (1C). These blended electrodes exhibit a clear synergy between the two carbon structures leading to improved rate performance.

[0395] Cycling performance of the cathodes (Gl, G2, and G3) at C / 3 is presented in FIG.16. The electrodes incorporating CNS / CNT blends (G2 and G3) exhibited similar capacity retention, retaining approximately 89% of their initial capacity after 300 cycles, superior to the electrode made solely with CNS (Gl). This improvement highlights the synergistic effect between CNS and CNT again, where the introduction of CNT could increase structural integrity and might also enhance the adhesion between the free-standing film and the current collector, thereby leading to more stable long-term cycling performance.Docket: 2020617PCTExample 10- NCM622 Cathodes Comprising CNS and / or CB

[0396] Selected cathode formulations and test electrodes were prepared in the same manner as described for the cathode formulations in Example 8, except that the conductive additive changed from CNS1 to CB3, or combination of CNS5 and CB3 processed together in SI at different ratios.

[0397] Two sets of NCM622 electrode films were prepared with a CB3 only as the reference, and combinations of CB3 and CNS5, namely CB3 / CNS5 (from Table A and Table 1, respectively) blended at 70:30 and 90: 10 ratio, targeting the dry film thickness of 110 gm upon calendering.

[0398] Table 8 shows amounts of carbon additive (1 wt.%) and amounts of PTFE (3 wt.% and 4 wt.%) employed to make free-standing electrode films, which were evaluated for film processibility; NCM representing the balance to 100 wt. %. In Table 8, “pass” indicates that a continuous with no minor crack and flexible film could be formed at —110 gm; “fail” indicates that no continuous and flexible film could be formed at ~1 lOgm.Table 8Formulation 4% PTFE 3% PTFE1% CB3 / CNS5 (70:30) Fail Fail1% CB3 / CNS5 (90:10) Pass Pass1% CB3 Pass Pass

[0399] At 1 wt.% of total carbon additive, both formulations containing a CB / CNS blend at 90:10 ratio and a CB only, in combination with PTFE loaded at 3 wt.% or 4% PTFE, delivered continuous high-quality, free-standing films. Moving toward higher ratio of CNS in the blends of CB3 / CNS5 (70 / 30) did not result in a continuous and flexible film formation at both 4% and 3% PTFE conditions (labeled as “fail” in Table 8).

[0400] FIG. 17 compares the tensile strength of NCM dry electrode films Hl and H2 as shown in Table 9. As shown, electrodes fabricated using a CB3 / CNS5 composite exhibit improved mechanical strength compared to those made with CB3 alone, when evaluated at identical NCM-carbon-PTFE loadings. The enhanced strength indicates that incorporating CNS into the CB network reinforces the film structure.Docket: 2020617PCTTable 9Formulation Active material Carbon additive CB / CNS Binder Average Dry Film ID ratio Thickness (gm) Hl 96% NCM622 1% CB3 100:0 3% PTFE 113H296% NCM622 1% CB3 / CNS5 90:10 3% PTFE 114

[0401] As shown in FIG. 18, electrodes prepared using CB3 / CNS5 blend (H2) also displayed lower electrode resistivity' relative to the pure CB3 -containing electrode (Hl), an advantageous effect for battery performance.ASPECTS

[0402] Aspect 1. A method for preparing an electrode composition, the method comprising: combining an active electrode material, a binder and carbon nanostructures; and processing the binder in the presence of the carbon nanostructures, wherein:the carbon nanostructures include a plurality of multiwall carbon nanotubes that are crosslinked to one another and branched: andprocessing the binder is conducted in the absence of solvent.

[0403] Aspect 2. The method of aspect 1, wherein the active electrode material, the binder, the carbon nanostructures and the electrode composition are loose particulate materials.

[0404] Aspect 3. The method of any of aspects 1 or 2, wherein the carbon nanostructures are provided in an amount no greater than about 3 % by weight based on the total weight of the electrode composition.

[0405] Aspect 4. The method of any of the preceding aspects, wherein the active electrode material is a lithium transition metal compound.

[0406] Aspect 5. The method of any of the preceding aspects, wherein the active electrode material is an active anode material selected from the group consisting of graphite, silicon, SiOx, silicon-graphite composite, silicon-carbon composite, lithium titanate, and any combination thereof.Docket: 2020617PCT

[0407] Aspect 6. The method of any of the preceding aspects, wherein the binder is a fibrillizable binder, a non-fibrillizable binder, or any combination thereof.

[0408] Aspect 7, The method of aspect 6, wherein the binder is PTFE, PVDF, HNBR or any combination thereof.

[0409] Aspect 8. The method of any of the preceding aspects, wherein the method is conducted in the presence of carbon nanostructures as the only fibril lating aid.

[0410] Aspect 9. The method of any of aspects 1 through 7, wherein the method is conducted m the presence of carbon nanostructures in combination with a multifunctional carbon black and / or carbon nanotubes, wherein the combination is the only fibrillating aid.

[0411] Aspect 10, The method of any of aspects 1 through 7, wherein the method is conducted in the presence of the carbon nanostructures and at least one other material selected from the group consisting of: an activated carbon, a non-fibnllizing conductive carbon additive and any combination thereof.

[0412] / Xspect 11. The method of any of the preceding aspects, wherein the carbon nanostructures are provided as flakes, pellets, granules or dry CNSs-containing composite.

[0413] / Xspect 12. The method of any of the preceding aspects, wherein the carbon nanostructures are coated carbon nanostructures.

[0414] Aspect 13. The method of aspect 12, wherein the coated carbon nanostructures are polyurethane-coated nanostructures or polyethylene glycol-coated carbon nanostructures.

[0415] / Xspect 14. The method of any of the preceding aspects, wherein the carbon nanostructures are pre-milled as a dry powder.

[0416] / Xspect 15. The method of any of the preceding aspects, wherein the carbon nanostructures are provided in a carbon nanostructure-polymer composite.

[0417] / Xspect 16. The method of any of the preceding aspects, wherein the carbon nanostructures are provided in a composite that includes carbon nanostructures and an active anode material selected from the group consisting of graphite, silicon, SiOx, silicon-carbon composite, sili con-graphite composite, and any combination thereof.Docket: 2020617PCT

[0418] Aspect 17. The method of any of the preceding aspects, wherein the electrode composition contains active material in an amount from about 92 wt % to about 99.8 wt %, binder in an amount of from about 0.1 wt % to about 5 wt % and a CNS component in an amount of from about 0.1 wt % to about 3 wt %.

[0419] Aspect 18. The method of any of the preceding aspects, wherein processing the binder in the presence of the carbon nanostructures includes a high shear operation sufficient to fibrillize a fibrillizable binder.

[0420] / Xspect 19. The method of aspect 18, wherein the high shear operation deforms a non-fibrillizable binder.

[0421] / Xspect 20. The method of any of the preceding aspects comprising one or more mixing operations, wherein all the mixing operations are conducted at shear conditions that are lower than shear conditions employed to process the binder.

[0422] Aspect 21. The method of any of the preceding aspects, wherein the electrode composition comprises at least one material selected from the group consisting of carbon nanostructures, fragments of carbon nanostructures and fractured carbon nanotubes, wherein the fragments of carbon nanostructures include a plurality of multiwall carbon nanotubes that are crosslinked to one another and branched, andwherein the fractured carbon nanotubes are multi wall carbon nanotubes that are derived from carbon nanostructures and are branched and share common walls with one another.

[0423] / Xspect 22. The method of any of the preceding aspects, wherein:at least one of the multi wall carbon nanotubes has a length equal to or greater than 2 microns, as determined by SEM,at least one of the multiwall carbon nanotubes has a length to diameter aspect ratio within a range of from 200 to 1000,there are at least two branches along a 2-micrometer length of at least one of the multiwall carbon nanotube, as determined by SEM,Docket: 2020617PCTat least one multiwall carbon nanotube exhibits an asymmetry7in the number of walls observed in the area after a branching point relative to the area prior to the branching point, and / or no catalyst particle is present at or near branching points, as determined by TEM.

[0424] Aspect 23, The method of any of the preceding aspects, wherein the multiwall nanotubes include 2 to 30 coaxial nanotubes, as determined by TEM at a magnification sufficient for counting the number of walls.

[0425] Aspect 24. The method of any of aspects 1 through 21, wherein at least 1% of the carbon nanotubes have a length equal to or greater than 2 microns, as determined by SEM, a length to diameter aspect ratio within a range of from 200 to 1000, and / or exhibit an asymmetry in the number of walls observed in the area after a branching point relative to the area prior to the branching point.

[0426] / Xspect 25. The method of any of the preceding aspects, wherein carbon nanostructures have:a BET surface area within a range from about 100 to about 400 m2 / g; and / oran average particle size (Dso) within a range of from about 5 to about 50 microns, as determined by laser diffraction analysis of powdery samples.

[0427] Aspect 26. A film or an electrode produced using the electrode composition prepared by the method of any of the preceding aspects.

[0428] 27. The method of any of aspects 1 through 25, further comprising processing the electrode composition to form a free-standing film, wherein the carbon nanostructures in the film act as: a conductive carbon additive, a fibrillizing agent and a mechanical reinforcer.

[0429] / Xspect 28. The method of aspect 27, wherein the free-standing film is formed by¬ calendaring the electrode composition.

[0430] / Xspect 29. The method of aspect 27 or 28, wherein the free-standing film has a tensile strength of at least 50 kPa and a thickness within a range of from about 30 and 500 gm.

[0431] / Xspect 30. The method of any of aspects 27 through 29, further comprising applying the free-standing film to a conductive substrate, to form a battery electrode.Docket: 2020617PCT

[0432] Aspect 31, A method further comprising applying the electrode composition prepared according to any of aspects 1 through 25 to a conductive substrate, to form a battery¬ electrode.

[0433] Aspect 32. The method of aspects 30 or 31, wherein the electrode has a thickness that is greater than about 40 microns

[0434] Aspect 33. A method for preparing an anode composition, the method comprising: combining an active anode material, a binder, and carbon nanostructures; andprocessing the binder in the presence of the carbon nanostructures, wherein:

[0435] the carbon nanostructures include a plurality of multiwall carbon nanotubes that are crosslinked to one another and branched; andthe binder is processed in the absence of solvent.

[0436] Aspect 34. The method of aspect 33, wherein the active anode material is graphite, Si / C composite, SiOx, silicon or any combination thereof.

[0437] Aspect 35, The method of aspects 33 or 34, wherein the carbon nanostructures and the active anode material are provided as dry, loose composite particles.

[0438] Aspect 36. The method of any of aspects 33 through 35, wherein the carbon nanostructures are provided in combination with a carbon black having a BET within a range from about 35 to about 420 m2 / g and an OAN within a range from about 120 to about 280 ml / 100g,

[0439] Aspect 37. The method of any of aspects 33 through 36, wherein the carbon nanostructures are provided in combination with a carbon black having one or more of the following properties: a surface energy of about 25 mJ / m2or less, a Raman microcrystal line planar size (La) within a range from about 10 to about 40 A, a mesoporous volume of at least about 0.05 cm3 / g, a total mesopore and macropore volume of at least 0.1 cm3 / g and a % crystallinity by Raman of at least 20%.

[0440] / Xspect 38. The method of aspects 36 or 37, wherein the weight % ratio of the carbon nanostructures to the carbon black is within a range of from about 1: 19 to about 1:1.Docket: 2020617PCT

[0441] Aspect 39, The method of aspects 36 or 37, wherein the weight % content of the carbon nanostructures in a blend comprising the carbon nanostructures and the carbon black is within a range of from about 5 to about 50 % of the blend.

[0442] Aspect 40. The method of aspects 33 through 35, wherein the carbon nanostructures are provided in combination with carbon nanotubes that are not part of or derived from the carbon nanostructures, the carbon nanotubes having a BET within a range from about 200 to about 500 m2 / g, a diameter within a range from about 2 to about 30 nm, and / or a Dso within a range from about 5 to about 500 microns.

[0443] Aspect 41. The method of any of aspects 33 through 35, wherein the carbon nanostructures are provided in combination with carbon nanotubes that are not part of or derived from the carbon nanostructures, wherein the weight % ratio of the carbon nanostructures to the carbon nanotubes is within a range of from about 1:19 to about 1:1.

[0444] Aspect 42. The method of any of aspects 33 through 35, wherein the carbon nanostructures are provided in combination with carbon nanotubes that are not part of or derived from the carbon nanostructures, wherein the weight % content of the carbon nanostructures in a blend comprising the carbon nanostructures and the carbon nanotubes is within a range from about 5 to about 50 wt % of the blend.

[0445] Aspect 43. A free-standing film or an anode prepared by the method any of the clams 33 through 42.

[0446] Aspect 44. A method for preparing a cathode composition, the method comprising: combining a cathode active material, a binder, and carbon nanostructures; andprocessing the binder in the presence of the carbon nanostructures, wherein:the carbon nanostructures include a plurality of multi wall carbon nanotubes that are crosslinked to one another and branched; andthe binder is processed in the absence of solvent.

[0447] / Xspect 45. The method of aspect 44, wherein the cathode active material is NCM, NCA, or LFP.Docket: 2020617PCT

[0448] Aspect 46, The method of aspect 44 or 45, wherein the carbon nanostructures are provided in combination with a carbon black and / or carbon nanotubes that are not part of or derived from the carbon nanostructures, wherein:the carbon black has a BET within a range from about 50 and about 1600 m2 / g, an OAN within a range from about 120 to about 650 ml / 100g, a surface energy of about 25 mJ / m2or less, a Raman microcrystalline planar size (La) of at least about 10A, a mesopore volume of at least about 0.05 cnr7g, a total mesopore and macropore volume of at least about 0.10 cm3 / g and / or a % crystallinity of at least 20%,wherein the carbon nanotubes have a BET within a range from about 200 to about 500 m2 / g. a diameter within a range from about 2 to about 30 nanometers and / or a Dso particle size within a range from about 5 to about 100 microns.

[0449] / Xspect 47. The method of aspects 44 or 45, wherein the weight % content of the carbon nanostructures in a blend comprising the carbon nanostructures together with the carbon black and / or the carbon nanotubes is within a range of from about 5 to about 50% of the blend.

[0450] Aspect 48. The method of aspects 44 or 45, wherein the weight % ratio of the carbon nanostructures to a blend comprising the carbon black and / or the carbon nanotubes is within a range of from about 1: 19 to about 1:1.

[0451] / Xspect 49. A free-standing film or a cathode, prepared by the method of any of aspects 44 through 48.

[0452] / Xspect 50. A method for preparing an electrode composition, the method comprising:(a) subjecting a binder to high shear conditions in the presence of carbon nanostructures; and (b) adding an electrode active material before, during or after step (a),wherein,the method is conducted without adding a solvent, andthe electrode composition comprises one or more of carbon nanostructures, fragments of carbon nanostructures and fractured carbon nanotubes,Docket: 2020617PCTwherein the carbon nanostructures and the fragments of carbon nanostructures include a plurality of multiwall carbon nanotubes that are crosslinked to one another and branched, and wherein the fractured carbon nanotubes are multiwall carbon nanotubes that are derived from carbon nanostructures and are branched and share common walls with one another.

[0453] Aspect 51, The method of aspect 50, wherein the carbon nanostructures are provided in combination with a carbon black and / or with carbon nanotubes that are not part of or derived from the carbon nanostructures.

[0454] Aspect 52. An electrode compositi on prepared by the method of aspects 50 or 51.

[0455] Aspect 53, A dry processed film comprising: an active electrode material, a processed binder and carbon nanostructures, fragments of carbon nanostructures and / or fractured carbon nanotubes,wherein, before any drying operation, the dry processed film contains solvent or solvent residue in an amount no greater than about 10 wt % relative to the theoretical weight of the film, wherein the carbon nanostructures or fragments of carbon nanostructures include a plurality of multiwall carbon nanotubes that are crosslinked to one another and branched, and wherein the fractured carbon nanotubes are derived from carbon nanostructures and are branched and share common walls with one another.

[0456] Aspect 54. The dry processed film of aspect 53, wherein, before any drying operation, the dry processed film contains solvent or solvent residue in an amount no greater than about 1 wt % relative to the theoretical weight of the film.

[0457] Aspect 55. The dry processed film of aspect 53 or 54, wherein the dry processed film is free-standing or laminated to a substrate.

[0458] Aspect 56. The dry processed film of any of aspects 53 through 55, wherein the carbon nanostructures, fragments of carbon nanostructures and / or fractured carbon nanotubes are the only fibnllating aid present in the film.Docket: 2020617PCT

[0459] Aspect 57. The dry processed film of any of clams 53 through 56, wherein the film is free-standing, has a tensile strength of at least about 50 kPa and a thickness within a range of from about 30 to about 500 microns.

[0460] Aspect 58. The dry processed film of any of aspects 53 through 57, wherein: at least one of the multi wall carbon nanotubes has a length equal to or greater than 2 microns, as determined by SEM,at least one of the multiwall carbon nanotubes has a length to diameter aspect ratio within a range of from 200 to 1000,there are at least two branches along a 2-micrometer length of at least one of the multiwall carbon nanotube, as determined by SEM,at least one multiwall carbon nanotube exhibits an asymmetry in the number of walls observed in the area after a branching point relative to the area prior to the branching point, and / or no catalyst particle is present at or near branching points, as determined by TEM.

[0461] Aspect 59. The dry processed film of any of aspects 53 through 57, wherein the multiwall nanotubes include 2 to 30 coaxial nanotubes, as determined by TEM at a magnification sufficient for counting the number of walls.

[0462] Aspect 60. The dry processed film of any of aspects 53 through 57, wherein at least 1% of the carbon nanotubes have a length equal to or greater than 2 microns, as determined by SEM, a length to diameter aspect ratio within a range of from 200 to 1000, and / or exhibit an asymmetry in the number of walls observed in the area after a branching point relative to the area prior to the branching point.

[0463] / Xspect 61. The dry processed film of any of aspects 53 through 60, wherein the dry- processed film further comprises a carbon black and / or carbon nanotubes that are not part of or derived from the carbon nanostructures.

[0464] Aspect 62. An electrode comprising the dry processed film of any of aspects 53 through 61.Docket: 2020617PCT

[0465] Aspect 63. The electrode of aspect 62, wherein the dry processed film is applied to a substrate.

[0466] Aspect 64. A battery comprising the electrode of aspect 62 or 63.

[0467] Aspect 65. A dried processed electrode comprising an active material in an amount of from about 92 wt % to about 99.8 wt %, binder in an amount of from about 0.1 wt % to about 5 wt % and an additive component in an amount of from about 0.01 wt % to about 3 wt %, wherein the additive component comprises carbon nanostructures

[0468] Aspect 66. The dried processed electrode of aspect 65, wherein the additive component further comprises a carbon black and / or carbon nanotubes that are not part of or are not derived from the carbon nanostructures.

[0469] Aspect 67. A method for preparing an anode composition, the method comprising: preparing a composite that includes an active anode material and carbon nanostructures; and processing a binder in the presence of the composite to produce the anode composition, wherein: the composite is in the form a loose dry particles;processing the binder is conducted in the absence of solvent, andthe carbon nanostructures include a plurality of multiwal l carbon nanotubes that are crosslinked to one another and branched.

[0470] Aspect 68. The method of aspect 67, wherein preparing the composite comprises: combining the active anode material with a dispersion containing the carbon nanostructures in a solvent, andremoving the solvent to obtain the composite in a form of loose dry particles.

[0471] Aspect 69. The method of aspect 67 or 68, wherein the composite in the form of loose dry particles is obtained by spray drying.

[0472] Aspect 70. The method of any of aspects 67 through 69, wherein the active anode material is graphite, Si, Si-graphite composite, Si-carbon composite, SiOx, or any combination thereof.Docket: 2020617PCT

[0473] Aspect 71, A composite material comprising carbon nanostructures and an active anode material selected from the group consisting of graphite, Si, Si-graphite composite, Si-C composite, SiOx, and any combination thereof, wherein:the carbon nanostructures are free of a growth substrate and include a plurality of multiwall carbon nanotubes that are crosslinked to one another and branched;the composite material has a particle size that is less than 30 microns; andat least one of the multi wall carbon nanotubes has a length equal to or greater than 2 microns, as determined by SEM,at least one of the multiwall carbon nanotubes has a length to diameter aspect ratio within a range of from 200 to 1000,there are at least two branches along a 2-micrometer length of at least one of the multiwall carbon nanotube, as determined by SEM,at least one multiwall carbon nanotube exhibits an asymmetry in the number of walls observed in the area after a branching point relative to the area prior to the branching point, and / or no catalyst particle is present at or near branching points, as determined by TEM.

[0474] As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items. Further, the singular forms and the articles "a", "an" and "the" are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms: includes, comprises, including and / or comprising, when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Further, it will be understood that when an element, including component or subsystem, is referred to and / or shown as being connected or coupled to another element, it can be directly connected or coupled to the other element or intervening elements may be present.

[0475] It will be understood that although terms such as “first” and “second” are used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. Thus, an element discussed couldDocket: 2020617PCTbe termed a second element, and similarly, a second element may be termed a first element without departing from the teachings of the present disclosure.

[0476] Unless otherwise defined, all terms (including 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. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0477] While this disclosure has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the disclosure encompassed by the appended claims.

Claims

Docket: 2020617PCTCLAIMSWhat is claimed is:

1. A method for preparing an electrode composition, the method comprising:combining an active electrode material, a binder and carbon nanostructures; and processing the binder in the presence of the carbon nanostructures, wherein:the carbon nanostructures include a plurality of multi wall carbon nanotubes that are crosslinked one another and branched; andprocessing the binder is conducted in the absence of solvent.

2. The method of claim 1, wherein the active electrode material, the binder, the carbon nanostructures and the electrode composition are loose particulate materials.

3. The method of any of claims 1 or 2, wherein the carbon nanostructures are provided in an amount no greater than about 3 % by weight based on the total weight of the electrode composition.

4. The method of any of the preceding claims, wherein the active electrode material is a lithium transition metal compound.

5. The method of any of the preceding claims, wherein the active electrode material is an active anode material selected from the group consisting of graphite, silicon, SiOx, silicon-graphite composite, silicon-carbon composite, lithium titanate, and any combination thereof.

6. The method of any of the preceding claims, wherein the binder is a fibrillizable binder, a non-fibrillizable binder, or any combination thereof.

7. The method of claim 6, wherein the binder is PTFE, PVDF, HNBR or any combination thereof.Docket: 2020617PCT8. The method of any of the preceding claims, wherein the method is conducted in the presence of carbon nanostructures as the only fibrillating aid.

9. The method of any of claims I through 7, wherein the method is conducted in the presence of carbon nanostructures in combination with a multifunctional carbon black and / or carbon nanotubes, wherein the combination is the only fibrillating aid.

10. The method of any of claims 1 through 7, wherein the method is conducted in the presence of the carbon nanostructures and at least one other material selected from the group consisting of: an activated carbon, a non-fibrillizing conductive carbon additive and any combination thereof.

11. The method of any of the preceding claims, wherein the carbon nanostructures are provided as flakes, pellets, granules or dry CNSs-containing composite.

12. The method of any of the preceding claims, wherein the carbon nanostructures are coated carbon nanostructures.

13. The method of claim 12, wherein the coated carbon nanostructures are polyurethane-coated nanostructures or polyethylene glycol-coated carbon nanostructures.

14. The method of any of the preceding claims, wherein the carbon nanostructures are premilled as a dry powder.

15. The method of any of the preceding claims, wherein the carbon nanostructures are provided in a carbon nanostructure-polymer composite.

16. The method of any of the preceding claims, wherein the carbon nanostructures are provided in a composite that includes carbon nanostructures and an active anode material selected from the group consisting of graphite, silicon, SiOx, silicon-carbon composite, silicon-graphite composite, and any combination thereof.Docket: 2020617PCT17. The method of any of the preceding claims, wherein the electrode composition contains active material in an amount from about 92 wt % to about 99.8 wt %, binder in an amount of from about 0.1 wt % to about 5 wt % and a CNS component in an amount of from about 0.1 wt % to about 3 wt %.

18. The method of any of the preceding claims, wherein processing the binder in the presence of the carbon nanostructures includes a high shear operation sufficient to fibrillize a fibrillizable binder.

19. The method of claim 18, wherein the high shear operation deforms a non-fibrillizable binder.

20. The method of any of the preceding claims comprising one or more mixing operations, wherein all the mixing operations are conducted at shear conditions that are lower than shear conditions employed to process the binder.

21. The method of any of the preceding claims, wherein the electrode composition comprises at least one material selected from the group consisting of carbon nanostructures, fragments of carbon nanostructures and fractured carbon nanotubes,wherein the fragments of carbon nanostructures include a plurality of multiwall carbon nanotubes that are crosslinked to one another and branched, andwherein the fractured carbon nanotubes are multiwall carbon nanotubes that are derived from carbon nanostructures and are branched and share common walls with one another.

22. The method of any of the preceding claims, wherein:at least one of the multiwall carbon nanotubes has a length equal to or greater than 2 microns, as determined by SEM,at least one of the multi wall carbon nanotubes has a length to diameter aspect ratio within a range of from 200 to 1000,Docket: 2020617PCTthere are at least two branches along a 2-micrometer length of at least one of the multi wall carbon nanotube, as determined by SEM,at least one multiwall carbon nanotube exhibits an asymmetry in the number of walls observed in the area after a branching point relative to the area prior to the branching point, and / orno catalyst particle is present at or near branching points, as determined by TEM.

23. The method of any of the preceding claims, wherein the multiwall nanotubes include 2 to 30 coaxial nanotubes, as determined by TEM at a magnification sufficient for counting the number of walls.

24. The method of any of claims 1 through 21, wherein at least 1% of the carbon nanotubes have a length equal to or greater than 2 microns, as determined by SEM, a length to diameter aspect ratio within a range of from 200 to 1000, and / or exhibit an asymmetry in the number of walls observed in the area after a branching point relative to the area prior to the branching point.

25. The method of any of the preceding claims, wherein carbon nanostructures have:a BET surface area within a range from about 100 to about 400 m2 / g; and / or an average particle size (Dso) within a range of from about 5 to about 50 microns, as determined by laser diffraction analysis of powdery samples.

26. The method of any preceding claim, wherein the active electrode material is an active anode material,27. The method of claim 26, wherein the active anode material is graphite, Si / C composite, SiOx, silicon or any combination thereof,28. The method of claims 26 or 27, wherein the carbon nanostructures and the active anode material are provided as dry, loose composite particles.Docket: 2020617PCT29. The method of any of claims 26 through 28, wherein the carbon nanostructures are provided in combination with a carbon black having a BET within a range from about 35 to about 420 m2 / g and an OAN within a range from about 120 to about 280 ml / 100g.

30. The method of any of claims 26 through 29, wherein the carbon nanostructures are provided in combination with a carbon black having one or more of the following properties: a surface energy of about 25 mJ / m2or less, a Raman microcrystalline planar size (La) within a range from about 10 to about 40 A, a mesoporous volume of at least about 0.05 cm3 / g, a total mesopore and macropore volume of at least 0.1 cm3 / g and a % crystallinity by Raman of at least 20%.

31. A method of any of claims 1 through 25, wherein the active electrode material is a cathode active material.

32. The method of claim 31, wherein the cathode active material is NCM, NCA, or LFP.

33. The method of claim 31 or 32, wherein the carbon nanostructures are provided in combination with a carbon black, wherein:the carbon black has a BET within a range from about 50 and about 1600 m2 / g, an OAN within a range from about 120 to about 650 ml / 100g, a surface energy of about 25 mJ / m2or less, a Raman microcrystalline planar size (La) of at least about lOA, a mesopore volume of at least about 0.05 cm3 / g, a total mesopore and macropore volume of at least about 0.10 cm3 / g and / or a % crystallinity of at least 20%,34. The method of any of claims 29, 30, or 33, wherein the weight % ratio of the carbon nanostructures to the carbon black is within a range of from about 1:19 to about 1:1.

35. The method of any of claims 29, 30, 33, or 34, wherein the weight % content of the carbon nanostructures in a blend comprising the carbon nanostructures and the carbon black is within a range of from about 5 to about 50 % of the blend.Docket: 2020617PCT36. The method of claims 26 through 35, wherein the carbon nanostructures are provided in combination with carbon nanotubes that are not part of or derived from the carbon nanostructures, the carbon nanotubes having a BET within a range from about 200 to about 500 m2 / g, a diameter within a range from about 2 to about 30 nm, and / or a Dso within a range from about 5 to about 500 microns.

37. The method of any of claims 26 through 36, wherein the carbon nanostructures are provided in combination with carbon nanotubes that are not part of or derived from the carbon nanostructures, wherein the weight % ratio of the carbon nanostructures to the carbon nanotubes is within a range of from about 1: 19 to about 1:1.

38. The method of any of claims 26 through 37, wherein the carbon nanostructures are provided in combination with carbon nanotubes that are not part of or derived from the carbon nanostructures, wherein the weight % content of the carbon nanostructures in a blend comprising the carbon nanostructures and the carbon nanotubes is within a range from about 5 to about 50 wt % of the blend.

39. A method for preparing an electrode composition, the method comprising:(a) subjecting a binder to high shear conditions in the presence of carbon nanostructures; and(b) adding an electrode active material before, during or after step (a),wherein,the method is conducted without adding a solvent, andthe electrode composition comprises one or more of carbon nanostructures, fragments of carbon nanostructures and fractured carbon nanotubes,wherein the carbon nanostructures and the fragments of carbon nanostructures include a plurality of multiwall carbon nanotubes that are crosslinked to one another and branched; and wherein the fractured carbon nanotubes are multiwall carbon nanotubes that are derived from carbon nanostructures and are branched and share common walls with one another.Docket: 2020617PCT40. The method of claim 39, wherein the carbon nanostructures are provided in combination with a carbon black and / or with carbon nanotubes that are not part of or derived from the carbon nanostructures.

41. The method of any preceding claim, further comprising processing the electrode composition to form a free-standing film, wherein the carbon nanostructures in the film act as: a conductive carbon additive, a fibrillizing agent and a mechanical reinforcer.

42. The method of claim 41, wherein the free-standing film is formed by calendaring the electrode composition.

43. The method of claim 41 or 42, wherein the free-standing film has a tensile strength of at least 50 kPa and a thickness within a range of from about 30 and 500 um.

44. The method of any of claims 41 through 43, further comprising applying the free-standing film to a conductive substrate, to form a battery electrode.

45. A method further comprising applying the electrode composition prepared according to any of claims 1 through 40 to a conductive substrate, to form a battery' electrode.

46. The method of claims 44 or 45, wherein the electrode has a thickness that is greater than about 40 microns.

47. An electrode composition prepared by the method of any one of claims 1 through 40,48. A film or an electrode produced using the electrode composition prepared by the method of any claims 1 through 40,49. A dry processed film comprising: an active electrode material, a processed binder and carbon nanostructures, fragments of carbon nanostructures and / or fractured carbon nanotubes,Docket: 2020617PCTwherein, before any drying operation, the dry processed film contains solvent or solvent residue in an amount no greater than about 10 wt % relative to the theoretical weight of the film, wherein the carbon nanostructures or fragments of carbon nanostructures include a plurality of multi wall carbon nanotubes that are crosslinked to one another and branched; and wherein the fractured carbon nanotubes are derived from carbon nanostructures and are branched and share common walls with one another.

50. The dry processed film of claim 49, wherein, before any drying operation, the dry processed film contains solvent or solvent residue in an amount no greater than about 1 wt % relative to the theoretical weight of the film.

51. The dry processed film of claim 49 or 50, wherein the dry processed film is free-standing or laminated to a substrate.

52. The dry processed film of any of claims 49 through 51, wherein the carbon nanostructures, fragments of carbon nanostructures and / or fractured carbon nanotubes are the only fibrillating aid present in the film.

53. The dry processed film of any of clams 49 through 52, wherein the film is free-standing, has a tensile strength of at least about 50 kPa and a thickness within a range of from about 30 to about 500 microns.

54. The dry processed film of any of claims 49 through 53, wherein:at least one of the multiwall carbon nanotubes has a length equal to or greater than 2 microns, as determined by SEM,at least one of the multiwall carbon nanotubes has a length to diameter aspect ratio within a range of from 200 to 1000,there are at least two branches along a 2-micrometer length of at least one of the multi wall carbon nanotube, as determined by SEM,Docket: 2020617PCTat least one multi wall carbon nanotube exhibits an asymmetry in the number of walls observed in the area after a branching point relative to the area prior to the branching point, and / orno catalyst particle is present at or near branching points, as determined by TEM.

55. The dry processed film of any of claims 49 through 54, wherein the multiwall nanotubes include 2 to 30 coaxial nanotubes, as determined by TEM at a magnification sufficient for counting the number of walls.

56. The dry processed film of any of claims 49 through 55, wherein at least 1% of the carbon nanotubes have a length equal to or greater than 2 microns, as determined by SEM, a length to diameter aspect ratio within a range of from 200 to 1000, and / or exhibit an asymmetry in the number of walls observed in the area after a branching point relative to the area prior to the branching point.

57. The dry processed film of any of claims 49 through 56, wherein the dry processed film further comprises a carbon black and / or carbon nanotubes that are not part of or derived from the carbon nanostructures.

58. An electrode comprising the dry’ processed film of any of claims 49 through 57.

59. The electrode of claim 58, wherein the dry’ processed film is applied to a substrate.

60. A battery comprising the electrode of claim 58 or 59,61. A dried processed electrode comprising an active material in an amount of from about 92 wt % to about 99.8 wt %, binder in an amount of from about 0.1 wt % to about 5 wt % and an additive component in an amount of from about 0.01 wt % to about 3 wt %, wherein the additive component comprises carbon nanostructures.Docket: 2020617PCT62. The dried processed electrode of claim 61, wherein the additive component further comprises a carbon black and / or carbon nanotubes that are not part of or are not derived from the carbon nanostructures.

63. A method for preparing an anode composition, the method comprising:preparing a composite that includes an active anode material and carbon nanostructures; andprocessing a binder in the presence of the composite to produce the anode composition, wherein:the composite is in the form a loose dry particles;processing the binder is conducted in the absence of solvent, andthe carbon nanostructures include a plurality of multiwall carbon nanotubes that are crosslinked to one another and branched.

64. The method of claim 63, wherein preparing the composite comprises:combining the active anode material with a dispersion containing the carbon nanostructures in a solvent, andremoving the solvent to obtain the composite in a form of loose dry particles.

65. The method of claim 63 or 64, wherein the composite in the form of loose dry particles is obtained by spray drying.

66. The method of any of claims 63 through 65, wherein the active anode material is graphite, Si, Si-graphite composite, Si-carbon composite, SiOx, or any combination thereof,67. A composite material comprising carbon nanostructures and an active anode material selected from the group consisting of graphite, Si, Si-graphite composite, Si-C composite, SiOx, and any combination thereof, wherein:the carbon nanostructures are free of a growth substrate and include a plurality of multiwall carbon nanotubes that are crosslinked to one another and branched;the composite material has a particle size that is less than 30 microns; andDocket: 2020617PCTat least one of the multiwall carbon nanotubes has a length equal to or greater than 2 microns, as determined by SEM,at least one of the multiwall carbon nanotubes has a length to diameter aspect ratio within a range of from 200 to 1000,there are at least two branches along a 2-micrometer length of at least one of the multi wall carbon nanotube, as determined by SEM,at least one multiwall carbon nanotube exhibits an asymmetry in the number of walls observed in the area after a branching point relative to the area prior to the branching point, and / orno catalyst particle is present at or near branching points, as determined by TEM.

Images