Electrode for energy storage device and method for manufacturing dry electrode film for energy storage device

Abstract

To provide a composition and a manufacturing method for an energy storage device electrode, which improve binder for holding electrode material with a reduced amount of binder and for improving the equivalent series resistance (ESR).SOLUTION: An electrolyte energy storage device 100 comprises a housing 120, electrodes 120, 104, a separator 106, and an electrolyte 122. The electrodes 102, 104 each include a first electrode film 112, 116 and a second electrode film 118, which contain super-fibrillated binder material and carbon. Increasing the fibrillization can increase binder adherence and film strength, and enables thinner films using a smaller amount of binder. Furthermore, since a larger amount of carbon-based conductive material can be added, the ESR can be reduced.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an energy storage device, and in particular to a composition and a method for producing an electrode for an energy storage device. and manufacturing methods. [Background technology]

[0002] Many different types of energy storage devices can be used to power electrical devices. Such electrical devices include, for example, capacitors, batteries, and capacitor-barreled Battery hybrid and / or fuel cell. Lithium ion capacitors, etc. Each energy storage device improves the composition of its electrodes to improve the electrical performance of the capacitor. It can be improved. Summary of the Invention

[0003] To summarize the present invention and the advantages it provides over the prior art, Certain objects and advantages are described herein. Not all such objects or advantages are necessarily specific. Therefore, for example, a person skilled in the art would understand that The present invention relates to a method for achieving or optimizing one or more of the advantages or groups of advantages described herein. It is not intended to limit the scope of the present invention to the specific embodiments described herein without necessarily achieving any of the objects or advantages stated or implied. It will be understood that the present invention may be implemented or practiced in various ways.

[0004] In a first embodiment, a dry carbon particle, a dry superfibrillated binder particle, and a current collector are used. and a body, the body comprising a free-standing dry electrode film, and an electrode for use in an energy storage device. Poles are provided.

[0005] In one embodiment of the first aspect, the dry electrode film has a thickness of about 50 μm to about 120 μm. In one embodiment of the first aspect, the electrode is an anode. In one embodiment, the free-standing dry electrode film further comprises conductive carbon. In one embodiment of the aspect, the electrode film comprises about 1% to about 5% by weight of conductive carbon. In one embodiment of the first aspect, the electrode comprises an electrolyte containing a lithium salt. In one embodiment of the first aspect, the electrolyte is further in ionic contact with the cathode. In one embodiment of the first aspect, the dried ultrafibrillated biomass is in ionic contact with the surface of the dried ultrafibrillated biomass. The ethylenediamine particles constitute about 3% to about 7% by weight of the free-standing dry electrode film. In one embodiment of the present invention, a lithium ion capacitor is provided that includes an electrode.

[0006] In a second embodiment, dried carbon particles and dried fibrillizable binder particles are mixed. forming a first dry electrode mixture containing a bipolar electrode; The ductility of the electrode film was then superfibrillated to form a superfibrillated matrix in the electrode film mixture. and calendering the ultrafibrillated electrode film mixture to form a forming a free-standing superfibrillated electrode film.

[0007] In one embodiment of the second aspect, the method is substantially free of processing additives. In one embodiment of the second aspect, the method comprises the step of forming a free-standing electrode film. and contacting the electrode with a current collector to form a first electrode. In one embodiment, the method includes forming a second electrode and providing a separator between the first electrode and the second electrode. In one embodiment of the second aspect, the first electrode is an anode. In one embodiment of the second aspect, the free-standing dry electrode film is about 50 μm to about In one embodiment of the second aspect, the dry superfibrillated binder has a thickness of 120 μm. The particles comprise about 3% to about 7% by weight of the superfibrillated matrix. In one embodiment, the step of forming the first mixture comprises adding conductive carbon particles to the first mixture. In one embodiment of the second aspect, the first mixture further comprises adding: The conductive carbon particles are contained in an amount of about 1% by mass to about 5% by mass. The process of superfibrillating the binder involves fibrillating the binder in the dry electrode film mixture. fibrillating the first fibrillated matrix to form a first fibrillated matrix; The process involves breaking down the binder particles to form a powder mixture of carbon particles and fibrillated binder particles. and fibrillating the powder mixture to form a second powder containing the superfibrillated matrix. forming a fibrillated matrix.

[0008] This specification contains at least one color drawing, a copy of which may be included in the claims and accompanying drawings. and the Office on payment of the necessary fees.

[0009] Other features, aspects, and advantages disclosed herein may be incorporated by reference in their entirety into specific embodiments. The drawings are intended to illustrate specific embodiments. and does not limit the present invention. [Brief explanation of the drawings]

[0010] [Figure 1]FIG. 1 is a side cross-sectional view schematically illustrating an example of an energy storage device according to an embodiment. [Figure 2] FIG. 2 is a flow chart showing an example of steps in a method for manufacturing an electrode film. [Figure 3] 1 is a table showing the equivalent series resistance performance of lithium ion capacitor cells having anodes containing different types of conductivity-enhancing additives. [Figure 4] FIG. 1 is a flow diagram showing an example of a method for manufacturing a thin electrode film. [Figure 5A] FIG. 1 is a schematic diagram of a payout machine for a calender line of an electrode film. [Figure 5B] FIG. 5B is a detailed view of a portion of the dispenser shown in FIG. 5A. [Figure 6A] 1 shows an SEM image of an electrode film prepared by prior art dry electrode processing. [Figure 6B] 1 shows SEM images of electrode films prepared by dry electrode processing using an ultrafibrillating binder. [Figure 7] 1 is a table showing data for various embodiments of lithium ion capacitors having anodes made by the methods provided herein.

[0011] While specific embodiments and examples are described below, those skilled in the art will appreciate that the present invention may be practiced in specific Beyond the disclosed embodiments and / or uses, obvious modifications and equivalents thereof It will be understood that the scope of the invention disclosed herein is therefore limited to the following: It should not be limited by the specific embodiments described.

[0012] In some embodiments, lithium ion batteries with improved electrical and / or mechanical performance are An energy storage device such as a lithium ion capacitor (LiC) is provided. In some embodiments, the device may include an electrode containing the improved electrode film composition. , which can provide improved electrical and / or mechanical performance. In some embodiments, the electrodes can be anodes and / or cathodes.

[0013] The disclosed embodiments provide enhanced fibrillation of binder materials compared to conventional methods; That is, the electrode film material undergoes "superfibrillation" as defined and described herein. The present invention may include composites, electrode films, electrodes, energy storage devices, and related methods. Many of the benefits in electrical and / or mechanical performance are due to the enhanced fibrillation of the binder. This can be achieved by:

[0014] For example, by enhancing the fibrillation of the binder, the adhesion and flexibility of the binder can be improved. Such embodiments may be equivalent to fibrillated films. Uses the same or less amount of binder than comparable films with no binder This may allow for the production of thinner films. Due to the self-supporting properties of dry electrode films and other reasons, wet electrode processing has traditionally been used. This could be beneficial for dry electrode film technology, which results in thicker films than conventional methods. Furthermore, the proportion of binder in the electrode film relative to some of the other materials, such as conductive materials, Lower weight percentages ("binder loading") have advantages in electrical performance For example, the use of ultrafibrillated binders and binders in electrode films The lower amount of binder also improves the film's fibrillation resistance compared to conventional films with conventional fibrillating binders. In comparison, the undesirable electrical series resistance (ESR) in devices using the film is low. It is possible.

[0015] In some embodiments, the anode and / or cathode electrode films are The electrode may contain other electrode materials such as a disintegratable binder material and carbon. Polarized films can be made with less binder material while maintaining desirable mechanical properties. Such desirable mechanical properties are useful, for example, in the manufacture of energy storage devices. This may involve mechanical properties required for one or more processes, e.g., dry manufacturing processes. When manufacturing an electrode by Advantageously, it provides sufficient stability for rolling, handling, and other handling. Furthermore, by enhancing the fibrillation of the binder material, the calender line This can advantageously facilitate the formation of thinner electrode films that can withstand tensions of In some embodiments, increased numbers of fibrils, greater fibril surface area, and Electrode films containing longer and / or longer fibrils may be obtained by increasing the number of fibrils desired during film fabrication. Reduce the thickness while still exhibiting sufficient mechanical strength to maintain the integrity of the film It is possible.

[0016] The method for manufacturing the electrode film is different from the conventional electrode film fibrillation process. The processing speed is slowed down to enhance the fibrillation of the binder material. and / or a fibrillation treatment step with increased treatment pressure. For example, Enhanced fibrillation results in an increase in the number of fibrils, an increase in the fibril surface area, and / or Alternatively, longer fibrils can be obtained from the binder material, which is different from the fibrils of conventional electrode films. Uses less binder material compared to chemical treatment processes while still maintaining desirable mechanical properties Such an increase in the number of fibrils, an increase in the surface area of ​​the fibrils, and / or Alternatively, longer fibrils may result in more effective matrix formation in the electrode film. This allows for a structure to be constructed that provides one or more of the advantages set forth herein. In some embodiments, this more effective matrix structure is Increased tensile strength, shear stress, and compression along the length compared to traditional dry electrode technology Resistance to stress and / or torsion stress, reduced film thickness, increased film density In certain embodiments, the electrode film may comprise a binder. This is a self-supporting electrode film with a reduced binder content so that it can be easily mounted.

[0017] In certain embodiments, the electrode film comprises ultrafibrillated binder particles and carbon particles. The ultrafibrillated binder particles are processed in process 200 and and / or binder particles produced according to the production methods set forth herein, such as 400. The binder particles are fibrillated, reduced in size, and then refibrillated. and at higher pressures, slower speeds, and slower feed rates than conventional fibrillation techniques. and / or binder particles that undergo fibrillation over a longer period of time. The fibrillated binder particles are characterized by the number of fibrils, the surface area of ​​the fibrils, and / or the fibril size. The rills can be structurally defined based on their length, all of which are conventional binder fillers. The ultrafibrillated matrix presented here increases the electrode flow rate. The structure formed by the components of the film mixture is The nanoparticles are hyperfibrillated to the point where they stick together, as shown in Figure 6B. The structure is such that it is not compressed and is not made into an electrode film.

[0018] In some embodiments, the ultrafibrillated binder particles have a maximum dimension of about 3 μm. (microns), less than about 2 μm, less than about 1 μm, less than about 0.5 μm, less than about 0.3 μm, less than about 0.1 μm less than about 0.05 μm, less than about 0.03 μm, less than about 0.01 μm, or any value therebetween, e.g., Approximately 0.01 to 3 μm, approximately 0.03 to 2 μm, approximately 0.05 to 1 μm, or approximately 0.1 μm to 0.3 μm In yet another embodiment, the superfibrillated matrix is ​​characterized by: particles, the carbon particles being at least 10%, at least 20%, at least 30%, At least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least At least 90%, at least 95%, or at least 99% of the surface area, or any range therebetween In some embodiments, the superfibrillated binder particles contact the binder particles at a surface area ranging from 0.1 to 1.0 μm. Compared with electrode films made by conventional dry processing with the same binder mass, the InDa particles Therefore, the number present in the electrode film is at least twice as large.

[0019] Dry particle electrodes fabricated using standard techniques with conventional fibrillating binders Conventional dry electrode films made from film mixtures by dry processing generally The anode is characterized by a thickness of about 120 μm or more, and the cathode The thickness of these two types is approximately 80 μm or more. The reason for the difference in the thickness of the dry electrodes is that the anode electrode film is thicker than the cathode electrode film. This is because they are difficult to compress, at least in part because, for example, It is difficult to compress the carbon material in the anode compared to the activated carbon in the cathode electrode film. Generally, such conventional cathode films have a thickness of about 80 μm to about 10,000 μm. The thickness of the anode film may range from about 120 μm to about 10,000 μm.

[0020] In some embodiments, the fibrillation of the binder material is enhanced over conventional dry electrode processes. Strengthening the electrode film can facilitate the formation of thinner electrode films. In particular, a thinner electrode film reduces the volume it occupies and can be used in a lithium-ion capacitor. In some embodiments, the ultrafibrillation of the binder material can be achieved by conventional fibrillation. The structural integrity of other similar conventional dry electrode films with fibrillated dry binder materials is less than about 80 μm, 60 μm, or 50 μm while maintaining integrity and / or electrical performance This can facilitate the formation of a cathode electrode film having a thickness. In some embodiments, electrode films produced by one or more of the processes described herein have a thickness of about 120 μm. The electrode may have a thickness of about 50 μm or less, such as 80 μm, 60 μm, or even less than about 50 μm, and the electrode may optionally In some embodiments, the enhanced fibrillation of the binder material is It may be easier to form anode electrode films with thicknesses of less than 120 μm. In an embodiment, by enhancing the fibrillation of the binder material, it is possible to obtain a film having a thickness of, for example, 120 μm. Thin electrode fillers such as less than 80μm, less than 60μm, less than 50μm, less than 40μm, and less than 30μm For example, the manufacture of anode electrode films with a thickness of less than 120 μm or thinner, and Thinner electrodes, such as cathode electrode films with thicknesses of less than 120 μm, less than 80 μm, or even thinner, In some embodiments, thinner electrode films can be manufactured with ease. The film can provide a lithium ion capacitor with improved power performance. In some embodiments, the anodes used in lithium ion capacitors have a thickness of about 40 μm to Approximately 120μm, approximately 50μm to approximately 120μm, approximately 50μm to approximately 80μm, approximately 60μm to approximately 100μm, approximately 80μm to approximately 120 In some embodiments, the lithium ion catalyst comprises an electrode film having a thickness of 1 μm. The cathodes used in the capacitors are about 40 μm to about 80 μm, about 40 μm to about 70 μm, and about 50 μm to about 8 The electrode film has a thickness of about 50 μm to about 70 μm.

[0021] In some embodiments, the electrode film may be conductive to facilitate a reduction in equivalent series resistance. Contains a performance enhancing additive. This additive is carbon black and / or graphite. In some embodiments, the electrode film may be different from a conventional electrode film. In comparison, the amount of binder material is low and the amount of one or more conductivity-enhancing additives is high, and therefore Therefore, the electrode film according to the embodiment has an equivalent series resistance while maintaining desirable mechanical properties. Indicates a drop in resistance.

[0022] Lithium ion electrodes comprising one or more electrodes containing the electrode film compositions described herein. The silicon capacitor advantageously exhibits a reduced equivalent series resistance, which allows it to be used in comparison with conventional electrode films. In some embodiments, the present invention provides a capacitor with a higher power density than conventional capacitors. The valence series resistance reduces heat generation, thereby improving the performance of lithium-ion capacitors with conventional electrode films. In some embodiments, the capacitors described herein reduce or avoid heat dissipation. Lithium ion capacitors comprising one or more electrodes containing the electrode film composition are more In some embodiments, one or more of the electrodes described herein may be used. The lithium ion capacitors containing the electrode compositions may be prismatic, cylindrical and / or boron. In some embodiments, the encapsulation material may have a variety of shapes, including a tongue shape. Lithium-ion capacitors with the electrolyte are widely used in hybrid electric vehicles (HEVs), powertrains, and powertrains. Powering plug-in hybrid electric vehicles (PHEVs) and / or electric vehicles (EVs) It can be used to provide

[0023] The electrodes and energy storage devices described herein are intended to be useful in the context of lithium ion capacitors. Although the present invention can be described in terms of one or more barriers, with or without lithium, Battery, capacitor, capacitor-battery hybrid, fuel cell, and combinations of these Any of a number of energy storage devices and systems, including but not limited to, In some embodiments, the electrodes can be used in ultracapacitors, lithium ion batteries, cathode or capacitor configured for use in a lithium-ion battery In a preferred embodiment, the electrode is a The anode is configured to

[0024] FIG. 1 is a schematic side cross-sectional view of an example of an energy storage device 100. The 00 may be a lithium-ion capacitor. Of course, other energy storage devices are also possible. Within the scope of the present invention, batteries, capacitor-battery hybrids, and / or It should be understood that the energy storage device 100 may include a fuel cell. 2, a second electrode 104, and a separator 106 disposed between the first electrode 102 and the second electrode 104. For example, the first electrode 102 and the second electrode 104 can be disposed on opposite sides of the separator 106. The first electrode 102 may be a cathode. , the second electrode 104 may be the anode, or vice versa (the first electrode 102 is the anode, The second electrode 104 may be a cathode. An electrolyte 122 may be provided to facilitate ionic transfer between the electrodes 102, 104 of the device 100. For example, the electrolyte 122 may be in contact with the first electrode 102 , the second electrode 104 , and the separator 106 . The electrolyte 122, the first electrode 102, the second electrode 104, and the separator 106 form the heart of the energy storage device. For example, the energy storage device housing 120 may be A first electrode 102, a second electrode 104, a separator 106 and an electrolyte 122 are introduced to form an energy storage device. After the electrolyte 122 is impregnated into the battery 100, the first electrode 102, the second electrode 104, the separator 106, and the electrolyte The material 122 may be sealed such that it is physically sealed from the environment outside the housing. Although the gas storage device 100 is shown as a dual electrode, dual layer device, other configurations, such as a single layer electrode, may be used. It will be appreciated that other types of

[0025] The energy storage device 100 may include any of several different types of electrolytes 122. For example, the device 100 may include an electrolyte for a lithium ion capacitor. The electrolyte may include a lithium source such as a lithium salt and a solvent such as an organic solvent. In some embodiments, the lithium salt is lithium hexafluorophosphate. Lithium (LiPF6), Lithium tetrafluoroborate (LiBF4), Lithium perchlorate (LiClO4) , bis(trifluoromethanesulfonyl)imide lithium (LiN(SO2CF3)2), trifluoromethanesulfonyl Lithium sulfonate (LiSO3CF3), combinations thereof, and / or In some embodiments, the solution of the lithium ion capacitor electrolyte is The catalyst may comprise one or more ethers and / or esters. For example, lithium The solvent for the electrolyte of the lithium ion capacitor is ethylene carbonate (EC), dimethyl carbonate (DMCO), etc. Dimethyl carbonate (DMC), diethyl carbonate (DEC), ethyl methyl carbonate (EMC), vinyl propylene carbonate (VC), propylene carbonate (PC), combinations thereof, and / or For example, the electrolyte may include LiPF6, ethylene carbonate, or the like. The solvents may include propylene carbonate, propylene carbonate, and diethyl carbonate.

[0026] The separator 106 has two electrodes, e.g., a first electrode 111, adjacent to each other on opposite sides of the separator 106. 102 and the second electrode 104 are electrically isolated while allowing ionic transfer between the two adjacent electrodes. The separator 106 can be configured to allow for a variety of porous, electrically insulating In some embodiments, the separator 106 comprises a polymer material. For example, the separator 106 can be made of a cellulose material (e.g., paper), polyethylene, or Polyethylene (PE) material, polypropylene (PP) material, and / or polyethylene and polypropylene The material may include propylene.

[0027] As shown in FIG. 1, the first electrode 102 and the second electrode 104 are connected to a first current collector 108 and a second current collector 110. The first current collector 108 and the second current collector 110 are connected to the corresponding electrodes and an external circuit (not shown). The first current collector 108 and / or the second current collector 109 can be easily electrically coupled to each other. The current collector 110 may contain one or more conductive materials and / or may be coated with a corresponding and terminals for coupling the energy storage device 100 to an external circuit, such as an external electrical circuit. They can be of various shapes and sizes that facilitate the transfer of charge between the collectors. The conductive material may be any material including aluminum, nickel, copper, silver, and alloys thereof. For example, the first current collector 108 and / or the second current collector 110 may be rectangular. The aluminum foil may be of a rectangular or substantially rectangular shape, and may have a corresponding electrode and Transfer of desired charge to or from an external electrical circuit (e.g., current collecting plates and / or electrodes) via another component of the energy storage device configured to electrically couple the The electrodes can be dimensioned to provide electrical charge transport.

[0028] The first electrode 102 is a first electrode 104 on a first surface of the first current collector 108 (e.g., the top surface of the first current collector 108). The film 112 (e.g., the upper electrode film) and the opposing second surface (e.g., a second electrode film 114 (e.g., a lower electrode film) on the bottom surface of the first current collector 108) and Similarly, the second electrode 104 is provided on a first surface of the second current collector 110 (e.g., a first electrode film 116 (e.g., top electrode film) on the top surface of the second current collector 110; a second electrode film 118 on the opposing second surface (e.g., the bottom surface of the second current collector 110); For example, the first surface of the second current collector 110 faces the second surface of the first current collector 108. The separator 106 is a second electrode film 114 of the first electrode 102 and a first electrode film 115 of the second electrode 104. It is adjacent to Mu 116.

[0029] The electrode films 112, 114, 116 and / or 118 may be of various suitable shapes, dimensions, and / or thicknesses. For example, the electrode film can be about 100 μm (microns) to about 25 μm thick. The thickness can be from about 30 μm to about 250 μm, including 0 μm.

[0030] In some embodiments, electrode films such as electrode films 112, 114, 116 and / or 118 One or more of the films may contain a mixture containing a binder material and carbon. In some embodiments, the electrode film may contain one or more additives, such as a conductivity-enhancing additive. In some embodiments, the cathode of the lithium ion capacitor may contain The electrode film of the electrode contains one or more carbon-based electroactive components, such as porous carbon materials. In some embodiments, the electrode film may contain a mixture of a cathode The porous carbon material includes activated carbon. For example, the cathode electrode film includes a binder material. , activated carbon, and conductivity-promoting additives. The anode electrode film of a lithium-ion capacitor reversibly transfers lithium ions. The electrode film contains a carbon-containing mixture that is configured to be tarcalating. In some embodiments, the lithium-intercalating carbon is graphite. For example, the anode electrode film is made of binder material, graphite, and conductive additives. It may contain an agent.

[0031] In some embodiments, the binder material comprises one or more fibrillizable binder components. For example, the process for forming the electrode film may include this fibrillating component. The binder component is fibrillated so that the electrode film contains the fibrillated binder. In some embodiments, the fibrillating binder can be The binder component comprises a superfibrillated binder particle having a plurality of fibrils. The fibrils may be fibrillated to separate one or more other components of the film. For example, a matrix of fibrils, a lattice and / or Alternatively, a web can be formed to provide the electrode film with a desired mechanical structure. For example, the cathode and / or anode of a lithium ion capacitor may contain one or more filters. One or more electrode films may be provided that contain a brilly binder component. In some embodiments, the binder component is polytetrafluoroethylene (PTFE), an ultra-high molecular weight Polyethylene (UHMWPE), and / or other suitable fibrillable materials, either alone or or a combination thereof.

[0032] In some embodiments, the electrode film may be formed from a material that is more flexible than conventional materials while maintaining desirable mechanical properties. In some embodiments, the binder material weight is less than that of known dry electrode films. The electrode film may be about 1% by weight to about 10% by weight, about 3% by weight to about 15% by weight, or about 3% by weight to about 10% by weight. %, about 3% to about 8% by weight, about 3% to about 7% by weight, about 3% to about 6% by weight, or about In yet another embodiment, the electrode film contains 3% to about 5% by weight of a binder material. , for example, about 5% to about 6% by weight, or about 6.5% to about 8% by weight, about 4% to about 7% by weight In some embodiments, the electrode film is an anode containing a binder material of about 7% by weight to about 11% by weight, for example, about 8% by weight to about 10% by weight, of a binder material, together with activated carbon. In some embodiments, an electrode film, such as an anode film, The composition may have a binder content of less than about 4% by weight or less than 3% by weight, for example, less than about 0.5% by weight. % to 4% by weight, 1% to 4% by weight, 0.5% to 3% by weight, or 1% to 3% by weight In some embodiments, electrode films with low binder content are more resistant to tension, shear, and A desired resistance to compressive and / or torsional stresses can be maintained.

[0033] In some embodiments, the electrode film may contain a binder relative to other materials in the film. The lower amount of material allows for increased amounts of conductivity-enhancing additives, improving electrical performance. For example, the anode according to such an embodiment may maintain desirable mechanical properties or In some embodiments, the equivalent series resistance can be improved while increasing the To achieve the desired electrical performance, certain types of conductivity-enhancing additives are included in the electrode film. For example, an electrode film with a low binder content can reduce the equivalent series resistance. Desired resistance to tensile, shear, compressive and / or torsional stresses while showing improvement in and thereby exhibiting a resistance of 0.1% compared to other conventional energy storage devices of comparable construction. energy storage devices such as lithium-ion capacitors, which have a higher power density compared to Manufacturing becomes easier.

[0034] In some embodiments, the conductivity-enhancing additive comprises conductive carbon. In an embodiment, the conductive carbon is one or more of carbon black and / or graphite. In some embodiments, the one or more carbon blacks include commercially available {Product} Ketjenblack® manufactured by Akzo Nobel NV, Im C-NERGY™ Super C65, manufactured by Imerys Graphite & Carbon, Ltd. Super P® manufactured by Cabot Corp., BP2000® manufactured by Cabot Corp., and / or LITX® 50 manufactured by Cabot Corp. In some embodiments, one or more of the above The graphite was commercially available from Superior Graphite Co., Inc., ABG1010 and / or Superior G ABG1005 manufactured by raphite Co., Ltd. For example, anode electrode filters for lithium ion capacitors The film may contain one or more of the conductivity-enhancing additives described herein. In some embodiments, the conductive carbon is present in an amount of about 1% by weight in the electrode film mixture. It may be from about 1% to about 10% by weight, including from about 8% to about 8% by weight, or from about 1% to about 5% by weight. In some embodiments, the electrode film may be made of a conductive carbon, as described herein. By incorporating conductive carbon, the energy storage device can achieve approximately 5 times the energy consumption compared to an energy storage device that does not contain conductive carbon. % ESR improvement. In yet another embodiment, the conductive carbon has a surface area of ​​10 ~100m 2 / g, e.g., 20-50m 2 / g, and / or particle size of 0.1 to 10 μm. In yet another embodiment, the conductive carbon has a particle size of about 0.1 μm to about 0.5 μm, or about 10 μm. In some embodiments, A lithium ion capacitor having an anode manufactured by the method has an ESR value of about 0.1 (m ohm) (milliohm) to about 10 (m ohm), for example, about 0.5 (m ohm) to about 5 (m ohm), or about 1.5 ( m ohm) to approximately 3.5 (m ohm).

[0035] In some embodiments, one or more of the electrode films described herein are prepared using a dry process. In this specification, the dry manufacturing process refers to the process for manufacturing an electrode film. It can refer to a process in which no or substantially no solvent is used in the formation of For example, the components of the electrode film can include dry particles. The dry particles for the electrode film can be mixed together to provide a dry particle electrode film mixture. In some embodiments, the electrode film comprises a dry particle weight percentage of the electrode film components. Dry manufacturing processes were used to ensure that the weight percentages of the electrode film mixture components were similar. In some embodiments, the dry particle electrode film can be formed from a dry particle mixture. The electrode film formed from the dry particle electrode film mixture by the manufacturing process It may be free or substantially free of processing solvents and solvent residues resulting therefrom. In some embodiments, a dry particle electrode film mixture is fabricated using a dry manufacturing process. The resulting electrode film may be cleaner and / or structurally stronger. This can result in improved electrochemical and / or mechanical performance. In some embodiments, the electrode film is formed by dry processing from a dry particle mixture. In some embodiments, the free-standing dry particle electrode film is The film consists essentially of dried carbon particles and dried superfibrillated binder particles. In some embodiments, the polymer may comprise or consist of a single fibrillating polymer, such as PTFE. Only a single binder is needed to form a free-standing dry electrode film such as a binder that can be Used.

[0036] In some embodiments, the energy storage device is not a battery.

[0037] FIG. 2 illustrates an example process 200 for manufacturing an electrode film, according to some embodiments. 1 is a flow diagram illustrating a process 200 for manufacturing an electrode film. is a dry processing process, and the resulting electrode film is free of liquids, solvents, and residues. In block 202, the carbon dioxide is removed from the carbon dioxide gas by the addition of a solvent or a liquid. An electrode film mixture is formed containing the particles and a binder material. In some embodiments, the electrode filler may be a conductive additive. The particle mixture is a dry particle mixture. In some embodiments, the binder material is a polytetrafluoroethylene (PTFE) binder. One or more of tetrafluoroethylene (PTFE) and ultra-high molecular weight polyethylene (UHMWPE) In some embodiments, the binder material comprises a fibrillizable polymer of PTFE. In some embodiments, the polymer comprises: The conductivity-enhancing additive can be one or more conductive carbons. For example, conductive carbons may contain one or more carbon blacks and / or graphites as described herein. This can be done.

[0038] In block 204, the binder in the electrode film mixture is superfibrillated to form a superfibrillated electrode film. The process of superfibrillation can form a fibrillated matrix. The polymerization can be carried out at a slower processing speed and / or at a higher processing pressure. For example, the process of superfibrillation is described in U.S. Patent Application Publication No. 2015 / 0072234. In some embodiments, the pressure may be reduced and / or depressurized compared to the previous embodiment. In some embodiments, the superfibrillation process may be a mechanical shearing process. the material can be mechanically treated to form a plurality of fibrils from the binder material; The binder material may be subjected to mechanical shear forces. The process of mechanical shearing includes mixing and / or milling. The particles of the rum mixture are provided to a blender and / or mill, and the blender and / or mill The rate at which the electrode filler is circulated through the mill may be reduced during the superfibrillation process. By slowing the rate at which particles of the gum mixture circulate through the blender and / or mill, The particles of the electrode film mixture are mixed in the process chamber of the blender and / or mill. In some embodiments, the time for this circulation can be increased. By increasing the time between the binders, the fibrillation of the mixture can be enhanced. In some embodiments, the particles of the electrode film mixture may be blurred. The circulation speed within the render and / or mill is determined by the speed at which the particles circulate once within the process chamber. The time required for the treatment should be determined to be approximately 1.2 to 3 times longer than that of conventional dry electrode treatment. For example, the mixing and / or grinding process time in conventional dry processing is approximately 1 minute. In some embodiments, the mixing and / or grinding time may be about 2 minutes, about 3 minutes, or about 4 minutes. , about 4 minutes, about 5 minutes, about 7 minutes, or about 10 minutes. The feeding rate of the mixing and / or grinding is Compared to conventional dry electrode processing, the speed can be reduced to about half. In an embodiment, the mixing and / or grinding feed rate is about 10% of the rated machine feed rate, Approximately 20% of the feed speed of the rated machine, approximately 30% of the feed speed of the rated machine, approximately 40% of the feed speed of the rated machine , about 50% of the rated machine feed rate, about 60% of the rated machine feed rate, about 100% of the rated machine feed rate 70%, approximately 80% of the rated machine feed rate, or approximately 90% of the rated machine feed rate. In some embodiments, the electrode film is formed by heating the dry mixture of carbon particles and binder for about 2 minutes to about 5 minutes. %. .

[0039] In some embodiments, a continuous mixing process can be performed. The mixing and / or grinding time may be inversely proportional to the feed rate. In such embodiments, conventional dry fillers may be used to increase the mixing and / or grinding time. The feed rate can be reduced compared to the Brillization process. By reducing this feed rate by half, the mixing and / or grinding time is doubled. For example, the feed rate for conventional dry processing in a particular machine is about 50-60 kg / hr. Thus, in some embodiments, the superfibrillated polymers provided herein The binder or matrix can be produced on the same machine with a feed rate of approximately 25-30 kg / hr. Generally, this feed rate depends on the milling machine and is described herein. In addition, the load can be adjusted based on the operating parameters of the machine. In this form, mixing and / or grinding can be performed using larger channel equipment. If a batch mixing and / or grinding process is used, the time can be increased. The processing time can be increased simply by mixing and / or grinding for a longer period of time. Cut.

[0040] In some embodiments, the processing in the blender and / or mill during the fibrillation process The processing pressure can be increased to achieve superfibrillation. As the force increases, more shear force is applied to the binder, which in turn In some embodiments, the treatment pressure for superfibrillation is The shear force applied to the insulating material is the same as that in the fibrillation process of conventional dry electrodes. It can be determined to be approximately 1.2 to 3 times larger.

[0041] The superfibrillation process, which is carried out at a slow processing speed and / or a high processing pressure, The number of fibrils formed from the binder material is increased by promoting enhanced fibrillation of the binder material. May promote increased fibril surface area and / or longer fibril lengths In some embodiments, slowing down the treatment speed and / or increasing the treatment pressure can This enhances fibrillation and allows for tensile, shear and To form an electrode film having a desired resistance to compressive and / or torsional stresses. For example, the treatment speed can be slowed down and / or the treatment pressure can be increased. This allows for a reduction in the amount of binder material while still providing the desired amount of one or more other components of the film. It is possible to promote the formation of a sufficient amount of fibrils to provide mechanical support for the In some embodiments, the mixing step of block 202 and the fibrillation step of block 204 are performed in a single step. The process may be one or substantially one continuous process.

[0042] In certain embodiments, the superfibrillation of block 204 is performed in the same manner as a conventional fibrillation process. This can be done by repeating the process two or more times for the same material. The first fibrillation step can form a fibrillated matrix. This fibrillated matrix can then be reduced in size, e.g., A powder electrode film mixture may be formed. For example, block 204 may be formed by mixing this first fiber. The method may include the step of breaking the ionized electrode film mixture. The breaking process involves passing the fibrillated electrode film mixture through a strainer, a sifter, a mesh This may include passing through a shredder, riddle, screen and / or sieve. The resulting fibrillated electrode film mixture is then subjected to a second fibrillation treatment as described herein. This second fibrillation step may be referred to herein as the superfibrillation step. As shown, in the fibrillation step performed at a slow processing speed and / or a high processing pressure, A second fibrillation step may result in a second powder electrode film mixture. The second powder electrode film mixture is then subjected to further processing steps in block 204. Alternatively, the process of block 206 may be performed. In this embodiment, a second (or additional) fibrillation step may be performed to produce an electrode film with enhanced fibrillation. Block 2 provides a fluoropolymer mixture and one or more of the benefits derived therefrom. The superfibrillation of the binder in 04 can be performed by fibrillating it once, twice, three times or more. Finally, in block 204, the ultra-fibers shown herein can be A fibrillated matrix and / or ultrafibrillated binder particles are obtained.

[0043] In block 206, the fibrillated electrode film mixture is calendered in a calendering device. The calendering device can be used to form a free-standing superfibrillated electrode film. are well known in the art and generally provided as raw materials such as electrode film mixtures. In some embodiments, the electrode film is formed by a pair of calender rolls. may be added to form a film with a desired minimum thickness, as further described herein. The electrode film is formed in the first calendaring process without an additional calendaring process. In some embodiments, the calendered mixture may be a liquid, a solvent, or a mixture of both. and a free-standing dry particle form free or substantially free of residues resulting therefrom. In some embodiments, the electrode film is an anode electrode film. In some embodiments, the electrode film is a cathodic electrode film. In some embodiments, the superfibrillated electrode film mixture is calendered under selected conditions. For example, in yet another embodiment, the calendering may be performed for 10 to 30 minutes. It can be done at a temperature of 0°C and a pressure of 5 to 150 kilonewtons. It may be of any size selected for the application, but generally ranges in diameter from 5 to 80 cm. That's fine. [Example]

[0044] Figure 3 shows a lithium-ion battery with an anode containing different types of conductivity-promoting additives. 1 is a table showing the equivalent series resistance of each of the capacitor cells. The type of conductivity-enhancing additive contained in the node and the corresponding equivalent series resistance determine the conductivity-enhancing additive. The percentage improvement is shown over a lithium-ion capacitor without additives. The conductivity-enhancing additives tested were mesoporous carbon and various types As shown in Figure 3, the conductive carbon contained a specific type of conductive carbon. Lithium-ion capacitors with anodes containing However, lithium ion capacitors with anodes containing mesoporous carbon exhibited equivalent For example, the use of certain types of conductive carbon did not result in significant improvement in series resistance. Lithium-ion capacitors with anodes that have an equivalent series resistance of 5% or more showed improvement.

[0045] Also, metal powders such as silver (Ag) powder, nickel (Ni) powder, or copper (Cu) powder are included. Lithium-ion capacitors with anodes containing ZnO showed significant improvements in equivalent series resistance. I didn't.

[0046] FIG. 4 illustrates a process 400 for manufacturing a thin electrode film, according to some embodiments. 1 is a flow diagram illustrating an example of a cathode electrode film. In some embodiments, the electrode film can be an anode electrode. In some embodiments, the electrode film can be made of a polymer. Step 400 is a dry processing step, which does not use liquids or solvents, and the resulting electrode film Free or substantially free of liquids, solvents and their residues. In some embodiments, step 400 may be performed to generate a charge from an ultracapacitor, a battery, and / or a lithium The electrodes of an ionic capacitor can be formed.

[0047] At block 402, an electrode film containing a binder material and one or more conductivity-enhancing additives is formed. The components of the film mixture can be mixed together. In some embodiments, the electrode film The rubber mixture is a dry particle mixture. The binder is polytetrafluoroethylene (PTFE). and one or more fibrillizable polymers, such as ultra-high molecular weight polyethylene (UHMWPE). In some embodiments, the binder material may include one type of polymer, such as PTFE. In some embodiments, the conductivity-enhancing additive comprises a polymer. For example, the conductive carbon may be one or more of the conductive carbons described herein. It may contain one or more types of carbon black and / or graphite.

[0048] At block 404, the electrode film mixture is mixed to form fibrils from the binder material. The fibrillation process may involve slow processing speeds and / or The process can be carried out at high processing pressures, while the slow processing speed and / or high processing pressures The pressure can cause tension, shear, compression and / or screw forces to form from a small amount of binder material. To form an electrode film having the desired resistance to stress, As described herein, in some embodiments, The fibrillation process may be a mechanical shearing process, such as a mixing process and / or a grinding process. In some embodiments, the electrode film mixture may be added during the fibrillation process. The rate at which the particles of the mixture circulate through the blender and / or mill can be slowed. In some embodiments, the internal processing of the blender and / or mill during the fibrillation process In some embodiments, the mixing step of block 402 and the processing pressure can be increased. and the fibrillation step of block 404 may be one or substantially one continuous step. Slower processing speeds and / or higher processing pressures may result in the above-mentioned larger Electrode films having high strength can be prepared, for example, from films less than 120 μm or as previously described herein. Thinner than previously possible, in a single high-pressure calendering step (single step) or multiple calendering process (e.g., after the first calendering process, the film is unwound) and one or more regalendering steps).

[0049] In certain embodiments, block 404 may include: The size of the fibrillated electrode film mixture can be reduced, for example, by breaking it. At block 406, the process may include reducing the size and refibrillating the fiber. The fibrillated electrode film mixture is calendered to form a first electrode film. In block 408, the first electrode film can be unwound. For example, The first electrode film is fed through a feeding machine as shown in FIGS. 5A and 5B, which will be described below. In block 410, the unwound electrode film is rewound at least once. In some embodiments, the electrode film can be about 50 μm or less. to form thin electrode films, such as those having thicknesses of 1000 nm or other thicknesses described herein. In some embodiments, the thin electrode may be recalendered two or more times. The film may have the desired resistance to tensile, shear, compressive and / or torsional stresses. For example, the calender line is drawn once. The thickness of the electrode film, such as the anode electrode film of a lithium-ion capacitor, that has been passed through The diameter of the fiber may be about 120 μm. The electrode film is made of high-strength, calendered electrode film, which is then unwound to a thickness of approximately 120 μm. One or more additional passes can be made through the calender line to reach a thickness of less than 1 / 2 mm. For example, the film may be calendered a second time to a thickness of, for example, about 80 μm or less. The recalendered anode electrode film can be unwound. After passing through the calendar line for the third time, an electrode film with a thickness of approximately 50 μm can be obtained. can.

[0050] In some embodiments, the electrode film may be less than 80 μm thick, or a conventional electrode film. Other electrode films described herein that are thinner than the film are made of ultrafibrillated binders. The electrode film mixture with the da is produced by passing it through the calender line only once. For example, calendering can increase the fibrillation rate due to its enhanced fibrillation. Due to the high strength of the film, the mixture can be calendered only once to a thickness of less than 80 μm. This can be done by exerting sufficient pressure on the electrode film mixture so that a desired thickness can be achieved. The electrode film mixture is processed once in a calendering device to form the desired electrode film. Reducing the demand for low-cost materials can provide cheaper and / or faster manufacturing processes. This can be done.

[0051] FIG. 5A is a schematic diagram of one embodiment of a payout machine for a calender line of an electrode film. FIG. 5B is a more detailed view of a portion of the dispenser shown in FIG. 5A. The apparatus shown can be used to perform the rechalendering step 410 of FIG. For example, in the illustrated embodiment, a free-standing dry electrode film (shown as a "feeding material" in FIG. 5B) The roll (shown as a circle) is unwound and re-calendered by the pair of rollers shown. A calendering device similar to the rollers shown in Figures 5A and 5B also applies the dried electrode mixture. 2 and step 410 of FIG. 4 or other embodiments. The first calendering step allows the initial formation of a free-standing dry electrode film. It will be understood that this is possible.

[0052] Figures 6A and 6B show SEM images of the dry electrode film matrix. SEM images of the dry electrode film matrix fabricated by conventional dry electrode processing are shown. FIG. 6B shows a graph of the nanofibers prepared according to step 200 or other ultrafibrillation processes described herein. The electrode film in Figure 6A shows the dry electrode film matrix fabricated with 8% binder. The electrode film in FIG. 6B contains 6.5% binder and has a thickness of 50 μm. The electrode film in Figure 6B is an electrode film mixture that has been subjected to two grinding processes. As can be seen from a comparison of Figures 6A and 6B, the dry electrode film in Figure 6B The matrix is ​​characterized by enhanced fibrillation of the binder. In Figure 6B, the number of fibrils increases. In Figure 6A, the carbon particles (shown in the figure) In Figure 6B, the fibrillated binder is a carbon particle. Generally, the binder shown in FIG. 6B covers a substantially increased surface area of ​​the polymer. 6A and has a larger surface area than the binder of FIG. 6A, and contacts the carbon particles over a larger surface area. The binder in Figure 6B is an example of the superfibrillating binders provided herein.

[0053] FIG. 7 illustrates various embodiments of anodes fabricated by the methods described herein. Regarding the lithium ion capacitor, the binder content, film thickness, capacitance The amount and ESR are shown.

[0054] While the present invention has been disclosed in the context of specific embodiments and examples, those skilled in the art will appreciate that the present invention may be practiced in a variety of ways. The invention may go beyond the specifically disclosed embodiment to other embodiments and / or other uses of the invention. It will be understood that the present invention is applicable to various uses, modifications, and the like. Although certain variations have been shown and described in detail, other variations which are within the scope of the invention are within the spirit and scope of the present invention. Certain features and aspects of these embodiments will be readily apparent to those skilled in the art based on the disclosure. Various combinations or subcombinations of the same may be made and are within the scope of the present invention. It should be understood that various features and aspects of the disclosed embodiments are within the scope of the present disclosure. or may be combined with one another to form various other aspects of the disclosed embodiments of the invention. It should be understood that the terms "a", "b", and "c" can be substituted for each other. The scope of the present invention should not be limited by the specific embodiments described above.

[0055] The headings used herein are for convenience only and do not limit the scope of the invention disclosed herein. It does not necessarily affect the scope or meaning of the apparatus and methods used.

Claims

1. An electrode film for an energy storage device, comprising: dry carbon particles and dry ultrafibrillated binder particles; the electrode film comprises a superfibrillated matrix comprising the dry superfibrillated binder particles; the superfibrillated matrix comprises the dry carbon particles having at least 10% of their surface area in contact with the dry superfibrillated binder particles; The electrode film is a dry, free-standing, ultrafibrillated electrode film that is free of solvent residue.

2. The electrode film described in claim 1, wherein the electrode film has a thickness of 50 μm to 120 μm.

3. The electrode film described in claim 1, wherein the electrode film contains conductive carbon.

4. The electrode film described in Claim 3, wherein the electrode film contains 1% to 5% by mass of the conductive carbon.

5. An electrode film as described in claim 1, wherein the dry superfibrillated binder particles constitute 5% to 7% by weight of the superfibrillated matrix.

6. The electrode film of claim 1, wherein the electrode film is substantially free of processing additives.

7. An electrode film as described in claim 1, wherein the dry ultrafibrillated binder particles comprise a binder selected from polytetrafluoroethylene and ultrahigh molecular weight polyethylene, and combinations thereof.

8. An electrode film as described in claim 1, wherein the maximum dimension of the dry ultrafibrillated binder particles is less than 3 μm.

9. The electrode film of claim 8, wherein the dry ultrafibrillated binder particles have a maximum dimension of 0.01 μm to 3 μm.

10. An electrode comprising the electrode film described in claim 1 and a current collector.

11. The electrode described in claim 10, wherein the electrode is an anode.

12. An energy storage device comprising the electrode described in claim 10.

13. The energy storage device of claim 12, wherein the electrode is in ionic contact with an electrolyte comprising a lithium salt.

14. The energy storage device of claim 12, which is a battery.

15. An electrode film for an energy storage device, comprising: dry carbon particles and dry ultrafibrillated binder particles. the electrode film comprises a superfibrillated matrix comprising the dry superfibrillated binder particles; the dry ultrafibrillated binder particles have a maximum dimension of less than 3 μm; The electrode film for an energy storage device is a dry, free-standing, ultrafibrillated electrode film that is free of solvent residue.

16. The electrode film of claim 15, wherein the maximum dimension of the dry ultrafibrillated binder particles is between 0.01 μm and 3 μm.

17. The electrode film of claim 15, wherein the electrode film is substantially free of processing additives.

18. The electrode film described in Claim 15, wherein the electrode film contains 1% to 10% by mass of the dry ultrafibrillated binder particles.

19. A method for producing a dry electrode film for an energy storage device, comprising: Producing a dry electrode film matrix comprising dry carbon particles and dry superfibrillated binder particles; superfibrillating fibrillizable dry binder particles contained in the dry electrode film matrix to form a superfibrillated matrix in the dry electrode film matrix; and calendering the ultrafibrillated dry electrode film matrix to form a dry, free-standing ultrafibrillated electrode film; The method of manufacturing an electrode film, wherein the ultrafibrillated matrix comprises the dry carbon particles having at least 10% of their surface area in contact with the dry ultrafibrillated binder particles.

20. The method of claim 19, which is a dry process substantially free of processing additives.

21. The method described in claim 19, wherein the dry superfibrillated binder particles constitute 5% to 7% by weight of the superfibrillated matrix.

22. The method described in claim 19, wherein the calendering treatment results in a thickness of the free-standing ultrafibrillated electrode film of 50 μm to 120 μm.

23. The method described in claim 22, wherein the calendering process to achieve a thickness of 50 μm to 120 μm is a single calendering process.

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