Compositions and methods for dry electrode films containing particulate non-fibrillating binders

Abstract

To provide new electrode film formulations that expand possibilities for electrode film formulations and improve performance.SOLUTION: A dry electrode film of an energy storage device comprises: a dry active material; and a dry binder comprising a fibrillizable binder and a microparticulate non-fibrillizable binder having a D50 particle size of about 1-10 μm. The microparticulate non-fibrillizable binder is selected from at least one of cellulose and a cellulose derivative. The dry electrode film is a free-standing type and substantially free of solvent residues.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 62 / 650,903, entitled "Compositions and Methods for Dry Electrode Films Comprising Particulate Non-Fibrillating Binders," filed March 30, 2018, the entire disclosure of which is incorporated herein.

[0002] The present invention relates generally to energy storage devices, and more particularly to materials and methods for dry electrode films containing particulate non-fibrillating binders. [Background technology]

[0003] Electrical energy storage cells are widely used to power electronic, electromechanical, electrochemical, and other useful devices. Such cells include batteries, such as primary chemical cells and secondary (rechargeable) cells, fuel cells, and various types of capacitors, including ultracapacitors. Increasing the operating power and energy of energy storage devices, including capacitors and batteries, is desirable to enhance energy storage, increase power capabilities, and broaden practical use cases. Summary of the Invention [Problem to be solved by the invention]

[0004] Energy storage devices containing electrode films with complementary attributes can improve the performance of energy storage devices in practical applications. Furthermore, existing dry and solvent-free manufacturing methods can impose practical limitations on electrode composition. Therefore, new electrode film formulations, and their manufacturing methods, can expand the possibilities for electrode film formulations and, consequently, improve performance. [Means for solving the problem]

[0005] For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects of the invention and its advantages are described herein. Not all such objects or advantages may be achieved in any particular embodiment of the invention. Thus, for example, one skilled in the art will recognize that the invention can be embodied or practiced in a manner that achieves or optimizes one or a group of advantages as taught herein, without necessarily achieving other objects or advantages that may be taught or suggested herein.

[0006] In a first aspect, a self-supporting dry electrode film is provided that includes a particulate, non-fibrillating binder having a particle size of about 0.5 μm to about 40 μm.

[0007] In a second aspect, a dry electrode film for an energy storage device is provided. Dry electrode films consist of a dry active material, a fibrillated binder, and a D of approximately 0.5 to 40 μm. 50 and a dry binder comprising a particulate non-fibrillating binder having a particle size of 1000 nm, wherein the dry electrode film is self-supporting.

[0008] In some embodiments, the particulate non-fibrillating binder has a D of about 1 to 25 μm. 50 In some embodiments, the dry binder comprises up to 50% by weight of a particulate non-fibrillating binder.

[0009] In some embodiments, the particulate non-fibrillating binder is a binder of cellulose and In some embodiments, the particulate non-fibrillating binder is selected from at least one of cellulose, cellulose esters, cellulose ethers, cellulose nitrate, carboxyalkyl cellulose, cellulose salts, and cellulose salt derivatives. In some embodiments, the particulate non-fibrillating binder is selected from at least one of cellulose, cellulose acetate, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose (HPC), hydroxyethyl cellulose (HEC), cellulose nitrate, carboxymethyl cellulose (CMC), carboxyethyl cellulose, carboxypropyl cellulose, carboxyisopropyl cellulose, sodium cellulose, sodium cellulose nitrate, and sodium carboxyalkyl cellulose. In some embodiments, the particulate non-fibrillating binder is selected from at least one of carboxymethyl cellulose (CMC) and polyvinylidene fluoride (PVDF). In some embodiments, the cellulose or cellulose derivative has a number average molecular weight of about 10,000 to about 500,000. In some embodiments, the cellulose derivative has a degree of substitution of about 0.7 to about 1.5.

[0010] In some embodiments, the fibrillating binder comprises polytetrafluoroethylene (PTFE). In some embodiments, the dry electrode film is substantially free of holes, cracks, and surface pits. In some embodiments, the dry electrode film has a tensile strength of at least about 1 N. In some embodiments, the dry active material comprises graphite.

[0011] In a third aspect, an electrode is provided that includes a dry electrode film in contact with a current collector. In a fourth aspect, a lithium ion battery is provided that includes the electrode.

[0012] In a fifth aspect, a method of manufacturing a dry electrode film for an energy storage device is provided, the method including treating a dry non-fibrillating binder with high shear to form a dry particulate non-fibrillating binder, combining the dry fibrillating binder with the dry particulate non-fibrillating binder to form a dry electrode film mixture, and calendering the dry electrode film mixture to form a free-standing dry electrode film.

[0013] In a sixth aspect, a method of manufacturing a dry electrode film for an energy storage device is provided, the method including providing a dry particulate non-fibrillating binder, mixing the dry particulate non-fibrillating binder with a dry first active material by a first non-destructive mixing process to form a dry bulk active material mixture, mixing the dry fibrillating binder with a second dry active material by a high shear mixing process to form a dry structural binder mixture, mixing the dry bulk active material mixture and the dry structural binder mixture by a second non-destructive mixing process to form a dry electrode film mixture, and manufacturing a free-standing dry electrode film from the dry electrode film mixture.

[0014] In some embodiments, the method further comprises treating the dry non-fibrillating binder with high shear to form a dry particulate non-fibrillating binder.

[0015] All of these embodiments are intended to be within the scope of the invention disclosed herein. These and other embodiments of the invention will become readily apparent to those skilled in the art from the following detailed description of the preferred embodiments, taken in conjunction with the accompanying drawings, although the invention is not limited to any particular preferred embodiment disclosed. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 shows an embodiment of an energy storage device. [Figure 2A] Figure 2A is a photograph of the inside of the grinding chamber of a jet mill with three jets pointing at the same point. [Figure 2B] FIG. 2B is an image of a classifier with a spinning wheel that selects the output size of the particles. [Figure 3A] FIG. 3A shows an SEM image of commercially available CMC particles. [Figure 3B] FIG. 3B shows jet-milled CMC particles processed according to Example 1. [Figure 4] FIG. 4 shows a chart providing the charge and discharge specific capacity of dry graphite anodes prepared according to Example 1, comparing anodes prepared from commercial CMC and milled CMC. [Figure 5A] FIG. 5A shows an image of an anode film prepared using commercially available CMC particles. [Figure 5B] FIG. 5B shows an image of an anode film prepared using jet-milled CMC particles according to the process of Example 1. [Figure 6] FIG. 6 provides a flow chart illustrating a method for producing a free-standing electrode film by combining a non-fibrillating binder with a fibrillating binder. [Figure 7] FIG. 7 provides a flow chart illustrating a method for parallel processing of electrode film binders. DETAILED DESCRIPTION OF THE INVENTION

[0017] Various embodiments of electrode films for use in energy storage devices are provided herein. In particular, in certain embodiments, the energy storage devices disclosed herein include electrode films containing a particulate, non-fibrillating binder having a specific particle size. The electrode films have been found to exhibit improved mechanical and processing properties. Also provided are methods for processing such particulate, non-fibrillating electrode film binders and methods for incorporating particulate, non-fibrillating binders into electrode films. The present disclosure reveals that improved uniformity of material distribution in electrode films can be achieved when the particle sizes of certain components are within the ranges provided herein.

[0018] Lithium-ion batteries have been relied upon as the power source for numerous commercial and industrial applications, for example, in consumer electronics, productivity devices, and battery-powered vehicles. However, the demands placed on energy storage devices are continually and rapidly increasing. For example, the automotive industry is developing vehicles, such as plug-in hybrids and pure electric vehicles, that rely on compact and efficient energy storage.

[0019] Several components that affect the storage potential of an energy storage device include the electrodes, and more specifically, the electrode film that comprises each electrode within the device. The electrochemical performance of an electrode, e.g., the capacity and efficiency of a battery electrode, is governed by various factors, such as the distribution of the active material, binder, and additives; the physical properties of the material, such as the particle size and surface area of ​​the active material; the surface characteristics of the active material; and the physical properties of the electrode film, such as cohesion and adhesion to conductive elements. Dry processing methods traditionally use high-shear and / or high-pressure processing steps to grind and mix electrode film materials, which can contribute to structural advantages over electrode films manufactured using wet processes.

[0020] In principle, electrode films with a more uniform distribution of active material, binder, and other components exhibit higher performance. It is generally believed that electrode films can suffer from performance degradation due to the mechanical properties of the film components and the interactions between them. For example, mechanical limitations can be attributed to poor adhesion between the active layer and the current collector, and poor cohesion in the electrode film, for example, between the active material and the binder. Such processes can result in performance losses in both power delivery and energy storage capacity. Performance degradation can be attributed to, for example, poor ionic conductivity, poor electrical conductivity, and so on. These degradation processes may be due to deactivation of the active material due to mechanical degradation, degradation of the active material, or a combination of these factors. For example, cell resistance may increase as adhesion between the active layer and the current collector decreases. Decreased cohesion between active materials can also lead to increased cell resistance, and in some cases, loss of electrical contact, potentially removing some of the active material from the ion and electron transport cycle in the cell. Without wishing to be limited by theory, it is believed that volume changes in the active material may contribute to such processes. For example, further degradation may be observed in electrodes incorporating certain active materials, such as silicon-based materials that undergo large volume changes during cell cycling. Lithium intercalation-deintercalation processes may correspond to such volume changes in some systems. In general, these mechanical degradation processes can be observed in any electrode, such as cathodes, anodes, positive electrodes, negative electrodes, battery electrodes, capacitor electrodes, hybrid electrodes, or electrodes of other energy storage devices. Increasing the uniformity of electrode film materials is expected to alleviate at least some of these issues.

[0021] More specifically, uniform distribution of the binder in an electrode film can provide a film with improved mechanical properties. Such improvements can provide many practical advantages. For example, an electrode film with a uniform distribution of the binder component can exhibit a reduced incidence of defects and / or a reduced severity of defects compared to an electrode film with a more non-uniform distribution of the binder material. For example, an electrode film with a uniform distribution of the binder component can exhibit higher tensile strength and / or ductility, which can facilitate the fabrication of energy storage devices. Specifically, an electrode film with higher tensile strength and / or ductility is easier to apply to a current collector or other substrate. These factors can be particularly relevant when dry electrode processing techniques are used, and the electrode film may be treated as a free-standing film, further defined herein as a "self-supporting film."

[0022] In principle, smaller particle sizes may allow for more uniform distribution of electrode film materials, including active materials, binders, and other components. However, in practice, some components may aggregate when reduced below a certain size threshold. Therefore, the particle sizes of various components of an electrode film may be advantageously incorporated within a range. In the present disclosure, it has been discovered that particulate non-fibrillating binders can be incorporated into electrode films at specific particle sizes. Achieving smaller particle sizes and more intimate contact of active materials, binders, and additives can lead to better devices. Smaller particle sizes may allow for more consistent manufacturing of electrode films. These electrode films may be manufactured using substantially identical processes and / or under substantially identical conditions, resulting in reduced variability in properties between electrode films manufactured.

[0023] If the electrode film is fabricated by a dry, solvent-free process, aqueous dispersions are not available and achieving a uniform dispersion of cellulose can be more difficult. Commercially available CMC in powder form generally has a D of approximately 40–70 μm. 50 The particle size is limited. More specific sizes within this range are limited to a specific degree of substitution. Larger particle sizes are believed to cause various problems, such as uneven CMC dispersion, localized pressure during calendering, and adhesion of CMC particles to the heated calender rollers, potentially leading to the issues described herein, such as electrode film defects. Reducing the cellulose particle size to match the active material particles is believed to improve the issues described herein. Because the CMC is better dispersed and on the order of the particle size of the active material particles, the calendering pressure is believed to be more uniformly distributed throughout the electrode film, resulting in greater consistency and less damage to active material particles such as graphite particles. Furthermore, improved film formation consistency may enable the production of uniform, continuous roll films.

[0024] Some embodiments include an electrode film manufactured by a dry process for use in a battery, the electrode film comprising a particulate non-fibrillating binder having a particle size ranging from 0.5 to 40 μm and at least one fibrillating binder. Embodiments include dry electrodes and manufacturing processes that provide particulate non-fibrillating binder particles having a size ranging from about 0.5 to about 40 μm, and electrode films incorporating such particulate non-fibrillating binder particles. Such electrode films may have a more uniform distribution of active material, binder, and other components. Electrode films incorporating such particulate non-fibrillating binder particles may exhibit improved tensile strength and / or processability. In certain embodiments, the particulate non-fibrillating binder is a cellulose, such as carboxymethyl cellulose (CMC). The electrode film is suitable for use as an anode in a lithium-ion battery. In certain embodiments, the electrode film comprises graphite.

[0025] Dry or self-supporting electrode films incorporating such fine, non-fibrillating binder particles can provide improved properties compared to typical electrode films. For example, the dry or self-supporting electrode films can provide one or more of improved film strength, improved cohesion, improved adhesion, improved electrical performance, or reduced defect incidence. Defects can include holes, cracks, and surface pits in the electrode film. The adhesion can be adhesion to a current collector. The electrical performance can be specific capacitance. The film strength can be tensile strength.

[0026] The electrode films described herein, or energy storage devices incorporating the electrode films described herein, can be advantageously characterized by improved specific capacity (which can be measured in mAh / g). Further improvements that can be realized in various embodiments include reduced capacity fade over the life of the device.

[0027] Some embodiments relate to dry electrode process technology. Dry electrode manufacturing processes may be those disclosed in one or more of U.S. Patent Application Publication No. 2006 / 0114643, U.S. Patent Application Publication No. 2006 / 0133013, U.S. Patent No. 9,525,168, or U.S. Patent No. 7,935,155, each of which is incorporated herein by reference in its entirety.

[0028] Further provided herein is a method for reducing the particle size of a particulate non-fibrillating binder. A pressurized jet milling process has been found to reduce the particle size of a particulate non-fibrillating binder. For example, the non-fibrillating binder can be placed in a jet mill and "jet milled" to reduce the median particle diameter (D) of the active material contained in the electrode film. 50 ) particle size. In some embodiments, the active material may be graphite having a median particle size of about 15 μm. In further embodiments, the particulate non-fibrillating binder may be a cellulose, such as CMC. Suitable pressurized jet milling conditions include a milling gas pressure of 100 to 500 psi. Jet milling can include separating the milled particles by particle size. For example, particles of the particulate non-fibrillating binder having a predetermined size can be separated using a classifier.

[0029] One embodiment is a method for fabricating a freestanding electrode film. Referring to Figure 6, method 600 can include selecting a non-fibrillating binder (605) and jet-milling the non-fibrillating binder to form a particulate non-fibrillating binder having a median particle size (610). Step 610 includes milling the non-fibrillating binder to produce particles on the order of the active material particle size, e.g., about 0.5 to about 40 μm, and combining the particulate non-fibrillating binder particles with the fibrillating binder and one or more The active material is combined with the above to form an electrode film mixture (615), and the electrode film mixture is calendered to form a self-supporting and / or free-standing electrode film (620). In some embodiments, each step is dry and solvent-free. In some embodiments, the particulate non-fibrillating binder is polyvinylidene fluoride (PVDF) and / or CMC. In further embodiments, the particulate non-fibrillating binder is CMC. In yet other embodiments, the fibrillating binder is PTFE. In yet other embodiments, the active material includes graphite. The method for producing a free-standing electrode film may include one or more parallel processing steps, such as those provided in FIG. 7.

[0030] Referring to FIG. 7 , the parallel processing method begins with an upper (as shown) parallel processing path 702 and a lower (as shown) parallel processing path 710. In the upper (as shown) parallel processing path 702, a bulk active material mixture 708 is formed by non-destructively mixing a bulk active material 704 with a non-fibrillating binder 706. The non-fibrillating binder 706 may be a particulate non-fibrillating binder, as previously described herein. The non-fibrillating binder 706 may be, for example, PVDF and / or CMC. The bulk active material 704 may be graphite. In the lower (as shown) parallel processing path 710, a second active material 712 and a structural binder 714 are combined under non-destructive mixing. The structural binder 714 may be PTFE, and the second active material 712 may be graphite. The mixed structural binder and second active material form an initial binder mixture 716, which is then jet-milled in a high-shear, high-intensity process to form a structural binder mixture 718. The bulk active material mixture 708 is then combined with the structural binder mixture 718 in a non-destructive mixing process to form a bulk active material and binder mixture 720, which is then processed by low-shear jet-milling to form an electrode film mixture 722. The low-shear jet-milling may be performed at a higher feed rate, for example, compared to the initial jet-milling used to form the structural binder mixture 718. The electrode film mixture 722 may then be pressed or calendered into a self-supporting and free-standing electrode film 724. Generally, no solvents are required at any stage of the process.

[0031] In various embodiments, dry powders, such as mixtures containing binder particles and active material particles, can be mixed by a gentle process using, for example, convection, air pressure, or diffusion mixers, such as tumblers with or without mixing media (e.g., glass beads, ceramic balls), paddle mixers, blade blenders, or acoustic mixers. The gentle mixing process can be non-destructive with respect to any active material in the mixture. Without limitation, the particle size of the graphite particles can be maintained after the gentle mixing process. In further embodiments, the powder mixing sequence and conditions can be modified to improve uniform distribution of the active material, binder, and any additives.

[0032] The materials and methods provided herein can be implemented with a variety of energy storage devices. As provided herein, the energy storage device can be a capacitor, a lithium ion capacitor (LIC), an ultracapacitor, a battery, a lithium ion battery, or a hybrid energy storage device that combines two or more aspects of the foregoing. In a preferred embodiment, the device is a lithium ion battery.

[0033] The energy storage device may be of any suitable shape, for example, flat, spiral wound, button-shaped, or pouch-shaped. The energy storage device may be a component of a system, for example, a power generation system, an uninterruptible power supply system, a solar power generation system, an energy recovery system for use in, for example, industrial machinery and / or transportation. The energy storage device may be a component of a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHIV), or a power storage system for power generation in ... The present invention may be used to power a variety of electronic devices and / or automobiles, including hybrid electric vehicles (PHEVs), and / or electric vehicles (EVs).

[0034] 1 shows a cross-sectional side schematic view of an example of an energy storage device 100 having an electrode film including a particulate non-fibrillating binder as provided herein. The energy storage device 100 can be classified as, for example, a capacitor, a battery, a capacitor-battery hybrid, or a fuel cell. In one embodiment, the device 100 is a lithium-ion battery.

[0035] The device has a first electrode 102, a second electrode 104, and a separator 106 disposed between the first electrode 102 and the second electrode 104. The first electrode 102 and the second electrode 104 are adjacent to opposing surfaces of the separator 106. The energy storage device 100 includes an electrolyte 118 to facilitate ionic communication between the electrodes 102, 104 of the energy storage device 100. For example, the electrolyte 118 may be in contact with the first electrode 102, the second electrode 104, and the separator 106. The electrolyte 118, the first electrode 102, the second electrode 104, and the separator 106 are contained within an energy storage device housing 120. One or both of the first electrode 102 and the second electrode 104 may include a particulate non-fibrillating binder, as described herein.

[0036] One or more of the first electrode 102, second electrode 104, and separator 106, or components thereof, may include a porous material. The pores within the porous material can provide containment and / or increased surface area for contact with the electrolyte 118 within the housing 120. The energy storage device housing 120 may be sealed around the first electrode 102, second electrode 104, and separator 106 and may be physically sealed from the surrounding environment.

[0037] In some embodiments, the first electrode 102 can be an anode (negative electrode), and the second electrode 104 can be a cathode (positive electrode). The separator 106 can be configured to electrically insulate two electrodes adjacent to opposite sides of the separator 106, such as the first electrode 102 and the second electrode 104, while allowing ionic communication between the two adjacent electrodes. The separator 106 can include a suitable porous, electrically insulating material. In some embodiments, the separator 106 can include a polymeric material. For example, the separator 106 can include a cellulose material (e.g., paper), a polyethylene (PE) material, a polypropylene (PP) material, and / or a polyethylene and polypropylene material.

[0038] Generally, the first electrode 102 and the second electrode 104 each include a current collector and an electrode film. The electrodes 102 and 104 include electrode films 112 and 114, respectively. The electrode films 112 and 114 can have any suitable shape, size, and thickness. For example, the electrode films can have a thickness of about 30 microns (μm) to about 250 microns, e.g., about 50 microns, about 100 microns, about 150 microns, about 200 microns, about 250 microns, about 300 microns, about 400 microns, about 500 microns, about 750 microns, about 1000 microns, about 2000 microns, or values ​​therebetween. The electrode films generally include one or more active materials, such as an anode active material or a cathode active material, as provided herein. The electrode films 112 and / or 114 can be dry and / or self-supporting electrode films as provided herein and have advantageous properties, such as tensile strength or capacitance, as provided herein. The first electrode film 112 and / or the second electrode film 114 may also include a particulate non-fibrillating binder as described herein, and may also include one or more additional binders. The electrode films 112 and / or 114 may be wet or self-supporting dry electrodes, as described herein.

[0039] As shown in FIG. 1 , the first electrode 102 and the second electrode 104 each have a first current collector 108 in contact with the first electrode film 112 and a second current collector 110 in contact with the second electrode film 114. The first current collector 108 and the second current collector 110 facilitate electrical connection between each corresponding electrode film and an external electrical circuit (not shown). The first current collector 108 and / or the second current collector 110 can comprise one or more conductive materials and have any suitable shape and size selected to facilitate the transfer of charge between the corresponding electrode and the external circuit. For example, the current collector can comprise a metallic material such as aluminum, nickel, copper, rhenium, niobium, tantalum, and materials including precious metals such as silver, gold, platinum, palladium, rhodium, osmium, iridium, and alloys and combinations thereof. For example, the first current collector 108 and / or the second current collector 110 can comprise, for example, aluminum foil or copper foil. The first current collector 108 and / or the second current collector 110 can have a rectangular or approximately rectangular shape sized to provide for the transfer of charge between the corresponding electrode and an external circuit.

[0040] In some embodiments, at least one active material comprises a treated carbon material, wherein the treated carbon material comprises a reduced number of hydrogen-containing functional groups, nitrogen-containing functional groups, and / or oxygen-containing functional groups, as described in U.S. Patent Application Publication No. 2014 / 0098464. For example, the treated carbon particles comprise a reduction in one or more functional groups on one or more surfaces of the treated carbon, e.g., from about 10% to about 60%, including from about 20% to about 50%, of the one or more functional groups compared to the untreated carbon surface. The treated carbon comprises a reduced number of hydrogen-containing functional groups, nitrogen-containing functional groups, and / or oxygen-containing functional groups. In some embodiments, the treated carbon material comprises less than about 1%, including less than about 0.5%, of hydrogen-containing functional groups. In some embodiments, the treated carbon material comprises less than about 0.5%, including less than about 0.1%, of nitrogen-containing functional groups. In some embodiments, the treated carbon material comprises less than about 5%, including less than about 3%, of oxygen-containing functional groups. In a further embodiment, the treated carbon material contains about 30% fewer hydrogen-containing functional groups than the untreated carbon material.

[0041] In some embodiments, the energy storage device 100 can be a lithium ion battery. In some embodiments, the electrode film of the lithium ion battery electrode can include a particulate non-fibrillating binder, one or more active materials, and a fibrillating binder matrix as described herein.

[0042] In further embodiments, the energy storage device 100 is charged with a suitable lithium-containing electrolyte. For example, the device 100 can include a lithium salt and a solvent, such as a non-aqueous or organic solvent. Generally, the lithium salt includes a redox-stable anion. In some embodiments, the anion can be monovalent. In some embodiments, the lithium salt can be selected from hexafluorophosphate (LiPF), lithium tetrafluoroborate (LiBF), lithium perchlorate (LiClO), lithium bis(trifluoromethanesulfonyl)imide (LiN(SOCF)), lithium trifluoromethanesulfonate (LiSOCF), and combinations thereof. In some embodiments, the electrolyte can include a quaternary ammonium cation and an anion selected from the group consisting of hexafluorophosphate, tetrafluoroborate, and iodide. In some embodiments, the salt concentration can be from about 0.1 mol / L (M) to about 5 M, from about 0.2 M to about 3 M, or from about 0.3 M to about 2 M. In further embodiments, the salt concentration of the electrolyte may be from about 0.7 M to about 1 M. In the electrolyte, the salt concentration may be about 0.2M, about 0.3M, about 0.4M, about 0.5M, about 0.6M, about 0.7M, about 0.8M, about 0.9M, about 1M, about 1.1M, about 1.2M, or any value therebetween.

[0043] In some embodiments, the electrolyte of the energy storage device can include a liquid solvent. The solvent need not dissolve all components, and need not completely dissolve any component of the electrolyte. In further embodiments, the solvent can be an organic solvent. In some embodiments, the solvent can include one or more functional groups selected from carbonates, ethers, and / or esters. In some embodiments, the solvent can include a carbonate. In further embodiments, the carbonate can be selected from cyclic carbonates such as, for example, ethylene carbonate (EC), propylene carbonate (PC), vinyl ethylene carbonate (VEC), vinylene carbonate (VC), fluoroethylene carbonate (FEC), and combinations thereof, or acyclic carbonates such as, for example, dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), and combinations thereof. In certain embodiments, the electrolyte can include LiPF6 and one or more carbonates.

[0044] In some embodiments, the lithium ion batteries are configured to operate at about 2.5 to 4.5 V, or 3.0 to 4.2 V. In further embodiments, the lithium ion batteries are configured to have a minimum operating voltage of about 2.5 V to about 3 V, respectively. In yet other embodiments, the lithium ion batteries are configured to have a maximum operating voltage of about 4.1 V to about 4.4 V, respectively.

[0045] As used herein, the terms "battery" and "capacitor" should be given their ordinary and customary meanings to those skilled in the art, and the terms "battery" and "capacitor" are not mutually exclusive. A capacitor or battery can refer to a single electrochemical cell that may operate alone or as a component of a multi-cell system.

[0046] As used herein, the voltage of an energy storage device is the operating voltage for a single battery or capacitor cell, whether the voltage is above the rated voltage or below the rated voltage under load or subject to manufacturing tolerances.

[0047] As provided herein, a "self-supporting" electrode film is an electrode film that incorporates a binder matrix structure sufficient to support the film or layer and maintain its shape so that the electrode film or layer can be self-supporting. When incorporated into an energy storage device, a self-supporting electrode film or active layer is one that incorporates such a binder matrix structure. Generally, and depending on the method employed, such electrode films have sufficient strength to be employed in the energy storage device manufacturing process without external support elements such as current collectors or other films. For example, a "self-supporting" electrode film can have sufficient strength to be wound, handled, and unwound within the electrode manufacturing process without other support elements. The dry electrode films described herein, such as cathode electrode films or anode electrode films, may be self-supporting.

[0048] As provided herein, a "solvent-free" electrode film is an electrode film that does not contain detectable process solvents, process solvent residues, or process solvent impurities. The dry electrode films described herein, such as the cathode electrode film or the anode electrode film, may be solvent-free.

[0049] As provided herein, a "wet" electrode, "wet process" electrode, or slurry electrode is an electrode prepared by at least one step involving a slurry of active material, binder, and optional additives. Wet electrodes generally contain detectable amounts of processing solvent residues and / or processing solvent impurities due to the solvents used during processing, even after the electrode has been dried.

[0050] As used herein, a "non-destructive" process is one in which the electrode active material, including its surface, is not substantially altered during the process. Therefore, the analytical properties and / or performance of the active material in applications such as incorporation into an energy storage device are the same or nearly the same as if it had not undergone the process. For example, a coating on the active material may be undisturbed or substantially undisturbed during the process. A non-limiting example of a non-destructive process is "non-destructive mixing or blending," such as jet milling due to reduced pressure, increased feed rate, decreased speed (e.g., blender speed), and / or changes in other process parameters, in which the shear imparted to the active material remains below a threshold at which the analytical properties and / or performance of the active material are adversely affected when implemented in an energy storage device. A "non-destructive" process can be distinguished from a high-shear process that substantially modifies the electrode active material, such as its surface, and substantially affects the analytical properties and / or performance of the active material. For example, high-shear blending or jet milling may have a detrimental effect on the surface of the electrode active material. High shear processes can be carried out to provide other benefits, such as fibrillating the binder material or forming a binder / active material matrix to aid in the formation of a self-supporting electrode film, without impairing the active material surface properties. Embodiments herein provide similar benefits while avoiding the detrimental effects of excessive use of high shear processes. Generally, non-destructive processes herein are carried out at one or more of higher feed rates, lower speeds, and / or lower pressures, resulting in a lower shear process than destructive processes that substantially alter the electrode active material and affect performance.

[0051] In some embodiments, the electrode films provided herein include at least one active material and at least one binder. The at least one active material can be any active material known in the art. The at least one active material may be a material suitable for use in a battery anode or cathode. Anode active materials can include, for example, intercalation materials (such as carbon, graphite, and / or graphene), alloyed / non-alloyed materials (such as silicon, silicon oxide, tin, and / or tin oxide), metal alloys or compounds (such as Si-Al and / or Si-Sn), and / or conversion materials (such as manganese oxide, molybdenum oxide, nickel oxide, and / or copper oxide), etc. The anode active materials can be used alone or mixed to form multiphase materials (such as Si-C, Sn-C, SiOx-C, SnOx-C, Si-Sn, Si-SiOx, Sn-SnOx, Si-SiOx-C, Sn-SnOx-C, Si-Sn-C, SiOx-Sn, or Sn-SiOx-SnOx). The cathode active material can be, for example, a metal oxide, a metal sulfide, or a lithium metal oxide. The lithium metal oxide can be, for example, lithium nickel manganese cobalt oxide (NMC), lithium manganese oxide (LMO), lithium iron phosphate (LFP), lithium cobalt oxide (LCO), lithium titanate (LTO), and / or lithium nickel cobalt aluminum oxide (NCA). In some embodiments, the cathode active material can be, for example, a layered transition metal oxide (LiCoO2 (LCO), Li(NiMnCo)O2 (NMC) and / or LiNi 0.8 Co 0.15 Al 0.05 O2 (NCA), spinel manganese oxides (LiMn2O4 (LMO) and / or LiMn 1.5 Ni 0.5 O4 (e.g., LMNO) or olivine (e.g., LiFePO4).

[0052] The at least one active material may include one or more carbon materials. The carbon materials may be selected from, for example, graphite materials, graphite, graphite-containing materials, hard carbon, soft carbon, carbon nanotubes, porous carbon, conductive carbon, or combinations thereof. The graphite may be synthetic or naturally derived. The activated carbon may be derived from a steam process or an acid / etching process. In some embodiments, the graphite material may be a surface-treated material. In some embodiments, the porous carbon may comprise activated carbon. In some embodiments, the porous carbon may comprise hierarchical structured carbon. In some embodiments, the porous carbon may comprise structured carbon nanotubes, structured carbon nanowires, and / or structured carbon nanosheets. In some embodiments, the porous carbon may comprise graphene sheets. In some embodiments, the porous carbon may be surface-treated carbon.

[0053] In some embodiments, a cathode electrode film for a lithium-ion battery or hybrid energy storage device can comprise about 70 wt% to about 98 wt%, including about 70 wt% to about 92 wt%, or about 70 wt% to about 96 wt%, of at least one active material. In some embodiments, a cathode electrode film can comprise up to about 5 wt%, or up to about 10 wt%, including about 1 wt% to about 5 wt%, of a porous carbon material. In some embodiments, a cathode electrode film can comprise up to about 5 wt%, including about 1 wt% to about 3 wt%, of a conductive additive. In some embodiments, a cathode electrode film can comprise up to about 20 wt%, for example, about 1.5 wt% to 10 wt%, about 1.5 wt% to 5 wt%, or about 1.5 wt% to 3 wt%, of a binder. In some embodiments, a cathode electrode film can comprise about 1.5 wt% to about 3 wt% of a binder.

[0054] In some embodiments, the anode electrode film can include at least one active material, a binder, and optionally a conductive additive. In some embodiments, the conductive additive can include a conductive carbon additive such as carbon black. In some embodiments, the at least one active material of the anode can include synthetic graphite, natural graphite, hard carbon, soft carbon, graphene, mesoporous carbon, silicon, silicon oxide, tin, tin oxide, germanium, lithium titanate, a mixture of the foregoing materials, or a composite. In some embodiments, the anode electrode film can include about 80 wt % to about 98 wt %, including about 80 wt % to about 98 wt %, or about 94 wt % to about 97 wt %, of the at least one active material. In some embodiments, the anode electrode film can include up to about 5 wt %, including 1 wt % to about 3 wt %, of the conductive additive. In some embodiments, the anode electrode film can include up to about 20 wt % of the binder, including about 1.5 wt % to 10 wt %, about 1.5 wt % to 5 wt %, or about 3 wt % to 5 wt %. In some embodiments, the anode electrode film includes about 4 wt % of the binder. In some embodiments, the anode film can be free of conductive additives.

[0055] Some embodiments include an electrode film, such as an anode and / or cathode, having one or more binders. The one or more binders may include a particulate non-fibrillating binder having a particle size ranging from 0.5 μm to 40 μm, as described herein, and in some embodiments, together with a fibrillating binder. The particulate non-fibrillating binder may be cellulose or a cellulose derivative. Examples of cellulose derivatives include cellulose esters such as cellulose acetate, cellulose ethers such as methyl cellulose, ethyl cellulose, hydroxypropyl cellulose (HPC), or hydroxyethyl cellulose (HEC), cellulose nitrate, or cellulose derivatives such as carboxymethyl cellulose (CMC), carboxyethyl cellulose, carboxypropyl cellulose, and the like. The cellulose or cellulose derivative may comprise a cellulose salt. In a further embodiment, the cellulose salt cation may be selected from sodium, ammonium, or lithium. For example, the cellulose or cellulose derivative may comprise sodium cellulose or a sodium cellulose derivative selected from sodium cellulose ester, sodium cellulose ether, sodium cellulose nitrate, or sodium carboxyalkylcellulose. In a preferred embodiment, the particulate non-fibrillating binder is CMC. The CMC may comprise sodium carboxymethylcellulose.

[0056] Cellulose derivatives can be characterized by their degree of substitution. For example, the degree of substitution may be about 0.7 to about 1.5, or about 1.2. When the material is implemented in an electrode film, a certain degree of substitution may be desirable to provide desired properties. However, commercially available CMC in powder form has been found to be limited to certain particle sizes and degrees of substitution. For example, commercially available CMC powders with a degree of substitution of 1.2 have been found to be available only in larger particle sizes. Smaller particle sizes, up to about 40 μm, have been found to be limited to a degree of substitution of 0.7, which is an undesirable degree of substitution. As mentioned above, smaller CMC powders have not been available because the need for such materials has not been recognized and the degree of substitution is certainly not desirable.

[0057] In some embodiments, the cellulose or cellulose derivative may include crosslinks. Furthermore, the cellulose or cellulose derivative can be characterized by its molecular weight, which is generally the number average molecular weight. In some embodiments, the cellulose or cellulose derivative has a number average molecular weight of about 10,000 to about 500,000, or about 50,000 to about 400,000.

[0058] The one or more binders can include polytetrafluoroethylene (PTFE), polyolefins, polyalkylenes, polyethers, styrene-butadiene, polysiloxanes and copolymers of polysiloxanes, branched polyethers, polyvinyl ethers, copolymers thereof, and / or mixtures thereof. The binder can include cellulose. The cellulose can be, for example, a carboxyalkyl cellulose such as carboxymethyl cellulose (CMC). In some embodiments, the polyolefin can include polyethylene (PE), polypropylene (PP), polyvinylidene fluoride (PVDF), copolymers thereof, and / or mixtures thereof. For example, the binder can include polyvinylene chloride, poly(phenylene oxide) (PPO), polyethylene-block-poly(ethylene glycol), poly(ethylene oxide) (PEO), poly(phenylene oxide) (PPO), polyethylene-block-poly(ethylene glycol), polydimethylsiloxane (PDMS), polydimethylsiloxane-coal alkylmethylsiloxane, copolymers thereof, and / or mixtures thereof. In certain embodiments, the fibrillating binder is PTFE. The dry self-supporting electrode film can include an interpenetrating network of the aforementioned binders. In some embodiments, the one or more binders include CMC, PVDF, and PTFE.

[0059] The binder can include various suitable ratios of polymer components. The particulate non-fibrillating binder can be up to 50% by weight of the binder. For example, the particulate non-fibrillating binder can be about 0.1% to about 50% by weight, about 0.5% to about 10% by weight, about 0.5% to about 5% by weight, about 0.5% to about 2% by weight, or about 0.5% to about 1% by weight. PTFE can be about 20% to about 98% by weight of the binder, including, for example, about 20% to about 95% by weight, about 20% to about 80% by weight, about 30% to about 70% by weight, about 30% to about 50% by weight, or about 50% to about 90% by weight. It can be about 90% by weight. In some embodiments, the one or more binders comprise about 0.1 to about 2% by weight CMC, about 0.1 to about 2% by weight PVDF, and about 1 to about 4% by weight PTFE. In certain embodiments, the one or more binders comprise about 1% by weight CMC, about 1% by weight PVDF, and about 2% by weight PTFE.

[0060] In some embodiments, the particulate, non-fibrillating binder particles may have a median particle size of about 0.5 μm to about 40 μm, e.g., about 1 μm to about 25 μm, about 2 μm to about 20 μm, about 5 μm to about 15 μm, or about 10 μm to about 15 μm. The electrode film mixture may further include binder particles other than the particulate, non-fibrillating binder particles, e.g., PTFE binder particles, having a selected size. In some embodiments, the binder particles may be about 50 nm, about 100 nm, about 150 nm, about 200 nm, about 250 nm, about 300 nm, about 350 nm, about 400 nm, about 450 nm, about 500 nm, about 1 μm, about 2 μm, about 3 μm, about 4 μm, about 5 μm, about 10 μm, about 50 μm, about 100 μm, or any value therebetween.

[0061] A dry manufacturing process can refer to a process that does not use, or substantially does not use, a solvent to form the electrode film. For example, the components of the electrode film, including the active material and the binder, may include dry particles. The dry particles for forming the electrode film can be combined to provide a dry particle electrode film mixture. In some embodiments, the electrode film may be formed from a dry particle electrode film mixture such that the weight percentages of the components of the electrode film and the weight percentages of the components of the dry particle electrode film mixture are substantially the same. In some embodiments, the electrode film formed from the dry particle electrode film mixture using a dry manufacturing process may be free of or substantially free of any processing additives, such as solvents and solvent residues resulting therefrom. In some embodiments, the resulting electrode film is a self-supporting film formed from the dry particle mixture using a dry process. In some embodiments, the resulting electrode film is a free-standing film formed from the dry particle electrode film mixture using a dry process. The process for forming the active layer or electrode film can include fibrillating a fibrillating binder component such that the film comprises a fibrillated binder matrix. In further embodiments, a free-standing electrode film may be formed in the absence of a current collector. In yet further embodiments, the electrode film may include a fibrillated polymer matrix such that the film is self-supporting. It is believed that a matrix, lattice, or web of fibrils can be formed to provide mechanical structure to the electrode film.

[0062] In some embodiments, an energy storage device electrode film, wherein the electrode film is a dry and / or self-supporting film comprising a particulate non-fibrillating binder described herein, can provide a specific capacity upon charge or discharge of about 300 mAh / g, about 325 mAh / g, about 350 mAh / g, about 375 mAh / g, about 400 mAh / g, about 425 mAh / g, about 450 mAh / g, about 500 mAh / g, or a range of values ​​therebetween. In further embodiments, an energy storage device electrode film, wherein the electrode film is a dry and / or self-supporting film comprising a particulate non-fibrillating binder described herein, can provide a first cycle efficiency of about 90%, about 91%, about 92%, about 93%, or a range of values ​​therebetween.

[0063] The electrode film can have a selected thickness suitable for a particular application. The thickness of the electrode film provided herein may be thicker than the thickness of an electrode film prepared by a conventional process. In some embodiments, the electrode film has a thickness of about 250 microns, about 300 microns, about 350 microns, about 400 microns, about 450 microns, about 500 microns, about 750 microns, about 1 mm, or about 2 mm, or any value therebetween. It can have a range of thicknesses.

[0064] In some embodiments, freestanding and / or self-supporting electrode films comprising the particulate non-fibrillating binders described herein may have a tensile strength of at least about 1 N. In further embodiments, the tensile strength may be about 1 N, about 1.1 N, about 1.2 N, about 1.3 N, about 1.4 N, about 1.5 N, about 1.6 N, about 1.7 N, about 1.8 N, about 1.9 N, about 2 N, greater than about 2 N, or a range of values ​​therebetween.

[0065] In some embodiments, a set of freestanding and / or self-supporting electrode films (e.g., a set of at least three electrode films) comprising a particulate non-fibrillating binder described herein, produced under substantially identical conditions, may have a variation in specific capacitance with a standard deviation (sd) of less than about 3%, e.g., about 2.5%sd, about 2%sd, about 1.5%sd, about 1%sd, about 0.5%sd, or a range of values ​​therebetween.

[0066] In some embodiments, freestanding and / or self-supporting electrode films comprising the particulate non-fibrillating binders described herein may be characterized by, for example, a specific energy density that is 20-30% higher than that of a wet battery electrode of comparable composition of active material.

[0067] In the specific examples below, electrode films were prepared that included a particulate non-fibrillating binder.

[0068] Example 1 Dry battery anode electrode films were fabricated containing 96 wt% graphite and 4 wt% binder, where the binder comprised 2% PTFE, 1% CMC, and 1% PVDF. Other electrode film compositions are envisioned and can be prepared, and the disclosure herein is not limited to the specific compositions disclosed.

[0069] The received CMC powder was milled using a Hosokawa 100AFG pressure jet mill with a classifier attachment to a size output selection. SigmaAldrich® sodium carboxymethylcellulose with a degree of substitution of 1.2 was used as the feed material. A D of 10 μm was used. 50 For size selection, a classifier rotation speed of 8000 rpm was used. The grinding gas pressure was 120 psi, and the initial chamber mass was 100 g. This resulted in a production rate of approximately 0.1 kg / hr. Photographs of the 100AFG machine can be seen in Figures 2A and 2B. The CMC powder received from SigmaAldrich® had a D of approximately 70 μm. 50 The particle size of Hosokawa CMC after grinding is about 10 μm.50 This difference can be seen in the SEM images in Figures 3A and 3B. When Hosokawa milled CMC was used in the dry anode electrode parallel process, improved first cycle efficiency and cell-to-cell uniformity were observed compared to as-received CMC. The electrochemical data for this comparison are shown in Figure 4. Using as-received CMC, charge / discharge specific capacities of 386 mAh / g and 348 mAh / g (90.2% efficiency) were achieved, respectively. Using milled CMC, charge / discharge specific capacities of 384 mAh / g and 349 mAh / g (90.9% efficiency) were achieved, respectively.

[0070] In addition to the improved electrochemical performance, the smaller D of CMC 50 The particle size improved electrode defects such as holes, cracks or surface pits. 50 The dry powder formulation using CMC powder with a particle size of 70 μm produced free-standing electrode films with defects as shown in Figure 5. These defects were observed in the D 50 This was avoided by using CMC milled to a particle size of approximately 10 μm. The basis for these experimental results is the smaller D 50 The larger surface area provided by the CMC particle size. At a fixed binder weight ratio in the electrode formulation, the higher surface area results in stronger bonding strength to the active material powder matrix. , and may provide a weaker affinity to the heated rollers used to produce the film or to calender the thickness of the film. In contrast, a larger D 50 The CMC particle size may provide a weaker bond strength to the active material powder matrix and a stronger affinity to the heated rollers used to produce the film or to calender the film thickness. This stronger affinity to the heated calender rollers is due to the larger D of the CMC binder particles found in unmilled powders that directly contact the heated calender rollers during dry processing. 50This can be attributed to the larger single spot size of the particle size. Thus, larger CMC particles are accidentally removed from the electrode powder sample during powder-to-film formation or extracted from the film during the film-to-film thickness reduction process, leaving defects in the electrode. Tensile strength measurements of freestanding electrode films also support the idea that the finely ground CMC polymer binder has strong bonding cohesive strength. The tensile strength results are consistent with a smaller D 50 Electrode films of similar thickness made with CMC binders of a larger particle size (10 μm vs. approximately 70 μm) are shown to be stronger than those made with larger particle sizes. The experimental results are shown in Table 1.

[0071] [Table 1]

[0072] While specific embodiments of the present invention have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the present disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms. Furthermore, various omissions, substitutions, and modifications to the systems and methods described herein may be made without departing from the spirit of the present disclosure. The appended claims and their equivalents are intended to cover such forms or modifications as fall within the scope and spirit of the present disclosure. Accordingly, the scope of the present invention is defined solely by reference to the appended claims.

[0073] It should be understood that features, materials, properties, or groups described in connection with a particular aspect, embodiment, or example are applicable to, to the extent incompatible with, any other aspect, embodiment, or example described in this section or elsewhere herein. All features disclosed herein (including the accompanying claims, abstract, and drawings), and / or all steps of any method or process so disclosed, may be combined in any combination, except where at least some of such features and / or steps are mutually exclusive. Protection is not limited to the details of the foregoing embodiments. Protection extends to any novel one, or any novel combination, of features disclosed herein (including the accompanying claims, abstract, and drawings), or any novel one, or any novel combination of steps of any method or process so disclosed.

[0074] Furthermore, certain features that are described in this disclosure in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, although features may be described above as acting in particular combinations, one or more features from a claimed combination may, in some cases, be deleted from the combination, and the combination may be claimed as a subcombination or a variation of the subcombination.

[0075] Furthermore, while operations may be illustrated in the figures or described herein in a particular order, such operations need not be performed in the particular order shown, or in any sequential order, or even all of the operations to achieve desired results. Other operations not shown or described may be incorporated into the example methods and processes. For example, one or more additional operations may be performed before, after, simultaneously with, or between any of the described operations. Furthermore, operations may be rearranged or resequenced in other embodiments. Those skilled in the art will appreciate that in some embodiments, the actual steps taken in the illustrated and / or disclosed processes may differ from those shown in the figures. Depending on the embodiment, some of the steps described above may be removed, and other steps may be added. Furthermore, the features and attributes of the specific embodiments disclosed above may be combined in different ways to form additional embodiments, all of which are within the scope of the present disclosure. Also, the separation of various system components in the above-described embodiments should not be construed as requiring such separation in all embodiments, and it should be understood that the described components and systems may generally be integrated into a single product or packaged into multiple products. For example, any of the components for the energy storage systems described herein may be provided separately or may be integrated (e.g., packaged together or attached together) to form an energy storage system.

[0076] For purposes of this disclosure, certain aspects, advantages, and novel features are described herein. Not necessarily all such advantages may be achieved in accordance with any particular embodiment. Thus, for example, one skilled in the art will recognize that the present disclosure may be embodied or carried out in a manner that achieves one advantage or group of advantages as taught herein, without necessarily achieving other advantages that may be taught or suggested herein.

[0077] Conditional language such as "can," "could," "could," and "may," unless otherwise specified or understood otherwise within the context in which it is used, is generally intended to convey that a particular embodiment includes certain features, elements, and / or steps, while other embodiments do not include the specified features, elements, and / or steps. Thus, such conditional language generally does not intend that the features, elements, and / or steps are in any way required by one or more embodiments, or that one or more embodiments necessarily include logic for determining, with or without user input or instruction, whether those features, elements, and / or steps are included in or should be performed in any particular embodiment.

[0078] Unless otherwise specified, conjunctions such as "at least one of X, Y, and Z" are understood apart from the context in which they are generally used to convey that an item, term, etc. can be either X, Y, or Z, and therefore such conjunctions are not generally intended to indicate that a particular embodiment requires the presence of at least one of X, Y, and at least one of Z.

[0079] As used herein, language of degree, such as the terms "approximately," "about," "generally," and "substantially," refers to a value, amount, or characteristic that approaches a stated value, amount, or characteristic that still performs a desired function or achieves a desired result.

[0080] The scope of the present disclosure is not intended to be limited by the specific disclosure of preferred embodiments in this section or elsewhere herein, but may be defined by the claims as they are presented in this section or elsewhere herein or as they may be presented in the future. Claim language is to be construed broadly based on the language employed in the claims and is not limited to the examples set forth herein, and is to be construed broadly during prosecution as well, and those examples are to be construed as non-exclusive.

Claims

1. A dry electrode film for an energy storage device, comprising: a dry active material; Fibrillating binder and D of 0.5 to 10 μm ５０ a dry binder comprising a particulate non-fibrillating binder having a particle size; the particulate non-fibrillating binder is selected from at least one of cellulose and cellulose derivatives; Freestanding and free of detectable solvent residues, with a strength of at least 1 N / mm ２ A dry electrode film having a tensile strength of

2. 10. The dry electrode film of claim 1, wherein the dry binder comprises up to 50% by weight of the particulate non-fibrillating binder.

3. 3. The dry electrode film according to claim 1, wherein the cellulose and the cellulose derivative are selected from at least one of cellulose, cellulose acetate, methyl cellulose, ethyl cellulose, hydroxypropyl cellulose (HPC), hydroxyethyl cellulose (HEC), cellulose nitrate, carboxymethyl cellulose (CMC), carboxyethyl cellulose, carboxypropyl cellulose, carboxyisopropyl cellulose, sodium cellulose, sodium cellulose nitrate, and sodium carboxyalkyl cellulose.

4. The dry electrode film according to any one of claims 1 to 3, wherein the particulate non-fibrillating binder comprises carboxymethyl cellulose (CMC).

5. The dry electrode film according to any one of claims 1 to 4, wherein the cellulose or the cellulose derivative has a number average molecular weight of 10,000 to 500,000.

6. The dry electrode film according to any one of claims 1 to 5, wherein the cellulose derivative has a degree of substitution of 0.7 to 1.

5.

7. A dry electrode film as described in claim 1 or 2, wherein the particulate non-fibrillating binder is selected from at least one of cellulose, cellulose ester, cellulose ether, cellulose nitrate, carboxyalkyl cellulose, cellulose salt and cellulose salt derivative.

8. The dry electrode film according to any one of claims 1 to 7, wherein the fibrillated binder comprises polytetrafluoroethylene (PTFE).

9. The dry electrode film according to any one of claims 1 to 8, wherein the dry electrode film is free of holes, cracks, and surface pits.

10. The dry electrode film has a resistance of at least 1.5 N / mm ２ The dry electrode film according to any one of claims 1 to 9, having a tensile strength of

11. The dry electrode film according to any one of claims 1 to 10, wherein the dry active material includes graphite.

12. The dry electrode film according to any one of claims 1 to 11, wherein the dry electrode film has a thickness of at least 250 µm.

13. The dry electrode film of claim 1 or 2, wherein the dry binder comprises an additional non-fibrillating binder.

14. 14. The dry electrode film of claim 13, wherein the additional non-fibrillating binder comprises polyvinylidene fluoride (PVDF).

15. The dry electrode film according to any one of claims 1 to 14, wherein the dry electrode film comprises at least 92 wt% of the dry active material.

16. An electrode comprising the dry electrode film of any one of claims 1 to 15 in contact with a current collector.

17. 17. A lithium ion battery comprising the electrode of claim 16.

18. 20. The lithium ion battery of claim 17 having a first cycle efficiency of at least 90%.

19. A dry electrode film described in any one of claims 1 to 12, wherein the particulate non-fibrillating binder includes polyvinylidene fluoride (PVDF).

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