Coated Electrodes

Abstract

The present disclosure relates to insulating electrode edge coating compositions and methods of making the same. Energy storage devices, such as lithium ion batteries, that utilize the insulating coating compositions are also described.

Description

[Technical field]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims priority to U.S. Provisional Patent Application No. 63 / 318,081, entitled "COATED ELECTRODES," filed March 9, 2022, the disclosure of which is incorporated by reference in its entirety herein.

[0002] FIELD OF THE DISCLOSURE This disclosure relates to energy storage devices and methods of making same. More specifically, this disclosure relates to insulated electrode edge coating compositions and methods of making and using same. [Background technology]

[0003] Many types of battery cells are currently used as energy sources in electric vehicles and energy storage applications. Many current cells use a jelly roll configuration in which the cathode, anode, and separator are wound together and have cathode and anode tabs for connecting to the positive and negative terminals of the cell can.

[0004] The path of current naturally travels through these tabs to a connector on the outside of the battery cell. However, if the current must travel out of the cell all the way across the cathode or anode to the tabs, ohmic resistance increases with distance. Furthermore, the tabs are additional components that add additional thickness to the device and must themselves be wound into a jelly roll, increasing costs and can pose manufacturing challenges. Summary of the Invention

[0005] For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of embodiments of the invention are described herein. Not all such objects or advantages may be achieved in any particular embodiment of the invention. Thus, for example, as will be appreciated by those skilled in the art, the invention may be embodied or implemented to achieve or optimize one advantage or advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.

[0006] In one aspect, a coated electrode foil is described that includes a foil including a first portion, a second portion, and a third portion, a carbon coating disposed over the first portion of the foil, and an insulating layer disposed over the second portion of the foil, the insulating layer including a ceramic material including a D50 particle size distribution range of about 1 nm to about 500 nm, and a high glass transition temperature binder.

[0007] In some embodiments, the high glass transition temperature binder has a glass transition temperature of at least about 140° C. In some embodiments, the ceramic material comprises a powder selected from the group consisting of alumina powder, boehmite powder, and combinations thereof. In some embodiments, the ceramic material comprises a D50 particle size distribution range of about 0.1 μm to about 0.3 μm. In some embodiments, the binder comprises at least one of polyvinylpyrrolidone (PVP), poly(N-vinylcaprolactam) (PNVCL), poly(vinylpyrrolidone-co-caprolactam), poly(n-vinylacetamide) (PNVA), ethylene-acrylic acid (EAA), or polyglycidyl ether.

[0008] In another aspect, an electrode is described that includes a coated electrode foil of the present disclosure and an electrode film disposed over a first portion of the foil. In some embodiments, a third portion of the coated electrode foil comprises a series of flags. In some embodiments, the electrode is in a wound configuration, and the series of flags are substantially interleaved. In some embodiments, the series of flags form a concentric circular pattern. In some embodiments, the distance between the series of flags ranges from 5 mm to 50 mm. In further embodiments, the distance between the series of flags ranges from 5 mm to 20 mm. In some embodiments, the electrode further comprises a gap disposed between the electrode film and the insulating layer.

[0009] In another aspect, an energy storage device is described that includes an electrode of the present disclosure, a second electrode, a separator disposed between the electrode and the second electrode, an electrolyte, and a housing, wherein the electrode, the second electrode, the separator, and the electrolyte are disposed within the housing. In some embodiments, the electrode is a cathode and the second electrode is an anode.

[0010] In another aspect, a method of preparing an electrode is described, the method including the steps of: coating a foil having a first portion and a second portion with an insulating layer over the second portion to form a coated electrode foil, where a carbon coating is disposed over the first portion of the foil, disposing an electrode film over the coated electrode foil, where a portion of the electrode film is disposed over the insulating layer, and removing a portion of the electrode film disposed over the insulating layer to form an electrode.

[0011] In some embodiments, the portion of the insulating layer comprises a smooth surface after the portion of the electrode film is removed. In some embodiments, the portion of the electrode film peels cleanly from the insulating layer during the positioning and removing steps. In some embodiments, the method further includes visually identifying a boundary of the electrode film and forming a counter electrode with an overhang that extends beyond the electrode.

[0012] In another aspect, an insulating material is described that includes a ceramic material having a D50 particle size distribution range of about 1 nm to about 500 nm and a high glass transition temperature binder.

[0013] In some embodiments, the ceramic material comprises a D50 particle size distribution range of about 0.1 μm to about 0.3 μm.

[0014] In another aspect, a method of preparing an electrode is described that includes coating a foil having a first portion and a second portion with an insulating layer over the second portion to form a coated electrode foil, where a carbon coating is disposed over the first portion of the foil, and disposing an electrode film over the first portion of the foil and over the carbon coating to form an electrode.

[0015] In some embodiments, the method further includes cutting the electrode film prior to disposing the electrode film over the first portion of the foil and over the carbon coating. In some embodiments, coating the foil includes disposing an insulating aqueous solution over the second portion. In some embodiments, the method further includes forming a gap disposed between the electrode film and the second portion. In some embodiments, the method further includes identifying the gap and forming a counter electrode having an overhang extending beyond the electrode. [Brief description of the drawings]

[0016] [Figure 1A] 1 illustrates a coating pattern for a coated electrode foil, according to one embodiment.

[0017] [Figure 1B] FIG. 1B is an enlarged view of FIG. 1A showing the coating pattern of a coated electrode foil according to one embodiment.

[0018] [Figure 2A] A perspective view of a battery cell can is shown.

[0019] [Figure 2B] FIG. 2B shows a side view of the battery cell can of FIG. 2A.

[0020] [Diagram 3] FIG. 1 illustrates a perspective view of material layers within a jelly roll, according to one embodiment.

[0021] [Figure 4] FIG. 2 illustrates a cross-sectional view of an end of a jelly roll, according to one embodiment.

[0022] [Figure 5A] 1 illustrates an end of a coated electrode foil with an edge coating according to one embodiment.

[0023] [Figure 5B] FIG. 5B is an enlarged view of FIG. 5A showing an end of a coated electrode foil with an edge coating according to one embodiment.

[0024] [Figure 6] FIG. 2 shows a cross-sectional view of a coating pattern of a coated electrode foil according to one embodiment.

[0025] [Figure 7] 1 is a flow chart of a process for preparing an electrode, according to one embodiment.

[0026] [Figure 8] 1 is a flow chart of a process for preparing an electrode, according to one embodiment.

[0027] [Figure 9A] 1 is a scanning electron microscope (SEM) image of a typical solvent-based ceramic slurry mixed with a solvent-based cathode slurry.

[0028] [Figure 9B] 1 is a top view photographic image of a solvent-based ceramic slurry mixed with a solvent-based cathode slurry.

[0029] [Figure 10] 1 is a line graph of electrolyte uptake factor for aged electrolytes with crosslinked and non-crosslinked binders.

[0030] [Figure 11] 1 is a line graph showing current versus voltage for a ceramic material of the present disclosure and an electrode with and without a cross-linked binder;

[0031] [Figure 12] 1 is a graph showing DSC curves of a crosslinked binder and a non-crosslinked binder.

[0032] [Figure 13] 1 is a graph of various ceramic particle cohesive strengths as a function of binder percentage.

[0033] [Figure 14] 1 is a graph of various ceramic coating adhesion strength as a function of binder percentage.

[0034] [Figure 15A] 1 is a scanning electron microscope (SEM) image of a typical insulating layer.

[0035] [Figure 15B] FIG. 15B is a magnified view of FIG. 15A, a scanning electron microscope (SEM) image of a typical insulating layer.

[0036] [Figure 15C] FIG. 15B is a magnified view of a scanning electron microscope (SEM) image of a typical insulating layer.

[0037] [Figure 15D] 1 is a scanning electron microscope (SEM) image of an insulating layer according to one embodiment.

[0038] [Figure 15E] FIG. 15D is a condensed view of a scanning electron microscope (SEM) image of an insulating layer, according to one embodiment.

[0039] [Figure 15F] FIG. 15B is a magnified view of the scanning electron microscope (SEM) image of the insulating layer of FIG. 15E, according to one embodiment.

[0040] [Figure 16A] 1 is a scanning electron microscope (SEM) image of an insulating layer according to one embodiment.

[0041] [Figure 16B] FIG. 16B is a magnified view of FIG. 16A of a scanning electron microscope (SEM) image of an insulating layer, according to one embodiment.

[0042] [Figure 17A] 1 is a scanning electron microscope (SEM) image of an insulating layer according to one embodiment.

[0043] [Figure 17B] FIG. 17B is a magnified view of FIG. 17A of a scanning electron microscope (SEM) image of an insulating layer, according to one embodiment.

[0044] [Figure 18A] 13 is an image of a delamination result of an electrode active material layer utilizing a typical insulating layer.

[0045] [Figure 18B] 1 is an image of an insulating layer delamination result using a typical insulating layer.

[0046] [Figure 19A] 13 is an image of a result of delamination of an electrode active material layer utilizing an insulating layer, according to one embodiment.

[0047] [Figure 19B] 1 is an image of an insulating layer delamination result utilizing an insulating layer, according to one embodiment.

[0048] [Figure 20]13 is an image of a lamination result utilizing an insulating layer using ammonium polyacrylate as a dispersant.

[0049] [Figure 21A] 1 is a photographic image of a coated cathode electrode with a gap between the electrode film and the insulating layer, according to one embodiment.

[0050] [Figure 21B] FIG. 21B is a magnified view of FIG. 21A, a photographic image of a coated cathode electrode with a gap between the electrode film and the insulating layer, according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0051] The present disclosure relates to insulating materials for use in electrodes in energy storage devices. The insulating materials may be applied to the edges of electrode layers as edge coatings to provide edge coating insulating layers. The edge coating insulating layers may promote improved charge and discharge cycling. Additionally, the edge coating insulating layers of the present disclosure peel cleanly away from the electrode active material layers during electrode fabrication. In some embodiments, there is no or substantially no intermixing of the insulating layer or ceramic coating with the electrode or electrode film.

[0052] In some embodiments, the insulating material of the present disclosure is coated on the electrode or coated electrode foil. In some embodiments, the coated electrode foil comprises an electrode foil and a carbon coating disposed over a portion of the electrode foil. In some embodiments, the insulating material acts as a dividing film between different electrodes. In some embodiments, the insulating material provides electrical insulation to the anode and / or cathode. In some embodiments, the insulating material disposed on the coated electrode foil does not adhere or bond to the electrode film during the lamination process.

[0053] Reference will now be made in detail to certain aspects or features, examples of which are illustrated in the accompanying drawings. Wherever possible, corresponding or like reference numbers are used throughout the drawings to refer to the same or corresponding parts.

[0054] Insulation layer The insulating layer of the present disclosure can comprise a ceramic material and a binder material. In some embodiments, the surface roughness of the insulating layer is about 0.01 μm, 0.02 μm, 0.03 μm, 0.04 μm, 0.05 μm, 0.06 μm, 0.07 μm, 0.08 μm, 0.09 μm, 0.1 μm, 0.11 μm, 0.12 μm, 0.13 μm, 0.14 μm, 0.15 μm, 0.16 μm, 0.17 μm, 0. 18 μm, 0.19 μm, 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, or 2 μm, or any range of values ​​therebetween. In some embodiments, the insulating layer has a low internal porosity, which prevents the insulating layer from denting or compressing during the dry electrode lamination process. It has been found that the use of spherical particles, which fit tightly together when dried, results in a low internal pore space. In contrast, it has been found that the use of non-spherical particles, even though they are small in size, forms voids during the drying process, resulting in a deformable coating. In some embodiments, the density of the insulating layer is about 1.8 g / cm 3 ,1.85g / cm 3 ,1.9g / cm 3 ,1.95g / cm 3 ,2g / cm 3 , 2.05g / cm 3 , 2.1g / cm 3 ,2.15g / cm 3 ,2.16g / cm 3 ,2.17g / cm 3 ,2.18g / cm 3 ,2.19g / cm 3 ,2.2g / cm 3 ,2.21g / cm 3 ,2.22g / cm 3,2.23g / cm 3 ,2.24g / cm 3 ,2.25g / cm 3 ,2.26g / cm 3 ,2.27g / cm 3 ,2.28g / cm 3 ,2.29g / cm 3 ,2.3g / cm 3 ,2.31g / cm 3 ,2.32g / cm 3 ,2.33g / cm 3 ,2.34g / cm 3 ,2.35g / cm 3 ,2.36g / cm 3 ,2.37g / cm 3 ,2.38g / cm 3 ,2.39g / cm 3 ,2.4g / cm 3 ,2.5g / cm 3 , or 2.6g / cm 3 In some embodiments, the density of the insulating layer is about 2.27 g / cm 3 In some embodiments, the density of the insulating layer is 1.72 g / cm 3 Greater than.

[0055] In some embodiments, it may be preferred that after drying, the insulating layer does not or does not substantially adhere to adjacent layers. In some embodiments, the thickness of the insulating layer is less than or at most the thickness of the conductive coating. In some embodiments, the insulating layer does not or does not substantially adhere to a film (e.g., wet or dry electrode film) applied to or placed over the current collector during the application process. In some embodiments, the insulating layer does not or does not substantially adhere to a functional film (i.e., dry battery electrode film) during a lamination process that utilizes heat and pressure to bond the functional film (i.e., dry battery electrode film) to a conductive adhesive that is also coated on the current collector.

[0056] Ceramic Materials In some embodiments, the insulating layer of the present disclosure comprises a ceramic material selected from the group consisting of boehmite, alumina, and combinations thereof. In some embodiments, the morphology of the ceramic material facilitates compact or dense packing of the ceramic, resulting in higher coating density. In some embodiments, the ceramic material provides improved adhesion qualities.

[0057] In some embodiments, the ceramic material is 0.01 μm, 0.02 μm, 0.03 μm, 0.04 μm, 0.05 μm, 0.06 μm, 0.07 μm, 0.08 μm, 0.09 μm, 0.1 μm, 0.11 μm, 0.12 μm, 0.13 μm, 0.14 μm, 0.15 μm, 0.16 μm, 0.17 μm, 0.18 μm, 0.19 μm, 0.20 μm, 0.21 μm, 0.22 μm, 0.23 μm, 0.24 μm, 0.25 μm, 0.26 μm, 0.27 μm, 0.28 μm, 0.29 μm, 0.30 μm, 0.31 μm, 0.32 μm, 0.33 μm, 0.34 μm, 0.35 μm, 0.36 μm, 0.37 μm, 0.38 μm, 0.39 μm, 0.40 μm, 0.41 μm, 0.42 μm, 0.43 μm, 0.44 μm, 0.45 μm, 0.46 μm, 0.47 μm, 0.48 μm, 0.49 μm, 0.50 μm, 0.51 μm, 0.52 μm, 0.53 μm, 0.54 μm, 0.55 μm, 0.56 μm, 0.57 μm, 0.58 μm, 0.59 μm, 0.60 μm, 0.61 μm, 0.62 μm, 0.63 μm, .19μm, 0.2μm, 0.3μm, 0.4μm, 0.5μm, 0.6μm, 0.7μm, 0.8μm, 0.9μm, 1μm, 1.1μm, 1.2μm, 1.3μm, 1.4μm, 1.5μm, 1.6μm, 1.7μm, 1.8μm, 1.9μm, or 2μm, or any range of values ​​therebetween, or approximately these values. 50 In some embodiments, the ceramic material has a particle size distribution of 0.01 μm, 0.02 μm, 0.03 μm, 0.04 μm, 0.05 μm, 0.06 μm, 0.07 μm, 0.08 μm, 0.09 μm, 0.1 μm, 0.11 μm, 0.12 μm, 0.13 μm, 0.14 μm, 0.15 μm, 0.16 μm, 0.17 μm, 0.18 μm, 0.19 μm, 0.20 μm, 0.21 μm, 0.22 μm, 0.23 μm, 0.24 μm, 0.25 μm, 0.26 μm, 0.27 μm, 0.28 μm, 0.29 μm, 0.30 μm, 0.31 μm, 0.32 μm, 0.33 μm, 0.34 μm, 0.35 μm, 0.36 μm, 0.37 μm, 0.38 μm, 0.39 μm, 0.40 μm, 0.41 μm, 0.42 μm, 0.43 μm, 0.44 μm, 0.45 μm, 0.46 μm, 0.47 μm, 0.48 μm, 0.49 μm, 0.50 μm, 0.51 μm, 0.52 μm, 0.53 μm, 0.54 μm, 0.55 μm, 0.56 μm, 0.57 μm, 0.58 μm, 0.59 μm, 0.60 μm, 0.61 μm, 0.62 μm, 0. In some embodiments, the ceramic material particles have an average particle size of about or at any range of values ​​therebetween, such as 0.2 μm, 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.1 μm, 1.2 μm, 1.3 μm, 1.4 μm, 1.5 μm, 1.6 μm, 1.7 μm, 1.8 μm, 1.9 μm, or 2 μm. In some embodiments, the ceramic material particles are spherical.

[0058] Table 1 summarizes the various ceramic materials utilized for the insulating layers. As discussed herein, Ceramic 1 and Ceramic 2 provided insulating layers that were not adhered to the electrodes but had desirable particle agglomeration. [Table 1]

[0059] Binder Materials In some embodiments, the binder material has a glass transition temperature or melting point such that the material does not act as an adhesive (e.g., a hot melt lamination adhesive) during the lamination process. In some embodiments, the binder material is selected from the group consisting of polyvinylpyrrolidone (PVP), poly(N-vinylcaprolactam) (PNVCL), poly(vinylpyrrolidone-co-caprolactam), polyglycidyl ether, poly(n-vinylacetamide) (PNVA), ethylene-acrylic acid (EAA), and combinations thereof. In some embodiments, the binder is crosslinked. In some embodiments, the binder is not crosslinked. In some embodiments, the binder material may be at 130°C, 131°C, 132°C, 133°C, 134°C, 135°C, 136°C, 137°C, 138°C, 139°C, 140°C, 141°C, 142°C, 143°C, 144°C, 145°C, 146°C, 147°C, 148°C, 149°C, 150°C, 151°C, 152°C, 153°C, 154°C, 155°C, 156°C, 157°C, 158°C, 159°C, 160°C, 161°C, 162°C, 163°C, 164°C, 165°C, 166°C, 167°C, 168°C, 169°C, 170°C, 171°C, 172°C, 173°C, 174°C, 175°C, 176°C, 177°C, 178°C, 179°C, 180°C, 181°C, 182°C, 183°C, 184°C, 185°C, 186°C, 187°C, 188°C, 189°C, 190°C, 191°C, 192°C, 193°C, 194°C, 195°C, 196°C, 197°C, 198°C, 199°C, 198°C, 199 The glass transition temperature is at or about 60°C, 161°C, 162°C, 163°C, 164°C, 165°C, 166°C, 167°C, 168°C, 169°C, 170°C, 171°C, 172°C, 173°C, 174°C, 175°C, 176°C, 177°C, 178°C, 179°C, 180°C, 181°C, 182°C, 183°C, 184°C, or 185°C, or any range of values ​​therebetween. In some embodiments, the binder material may be at least 130°C, 131°C, 132°C, 133°C, 134°C, 135°C, 136°C, 137°C, 138°C, 139°C, 140°C, 141°C, 142°C, 143°C, 144°C, 145°C, 146°C, 147°C, 148°C, 149°C, 150°C, 151°C, 152°C, 153°C, 154°C, 155°C, 156°C, 157°C, 158°C, 159°C, , 160°C, 161°C, 162°C, 163°C, 164°C, 165°C, 166°C, 167°C, 168°C, 169°C, 170°C, 171°C, 172°C, 173°C, 174°C, 175°C, 176°C, 177°C, 178°C, 179°C, 180°C, 181°C, 182°C, 183°C, 184°C, or 185°C, or any range of values ​​therebetween, or about these values.

[0060] In some embodiments, the binder material may be able to adhere well to the current collector foil and also have sufficient cohesive strength between particles in the insulating layer. In some embodiments, the binder material may be able to withstand highly electrochemically reducing and / or oxidizing conditions (specific to the applied electrode current collector - oxidizing at the positive electrode, reducing at the negative electrode) in the electrochemical cell. In some embodiments, the binder material may be able to withstand prolonged contact with solvents, salts, and other chemical species present in the electrolyte. In some embodiments, the binder material may retain or substantially retain its adhesive and cohesive strength over the useful life of the cell.

[0061] Coated electrode foil In some embodiments, the insulating material of the present disclosure is coated on the electrode or coated electrode foil. In some embodiments, the coated electrode foil comprises an electrode foil and a carbon coating disposed over a portion of the electrode foil. In some embodiments, the insulating material acts as a dividing film between different electrodes. In some embodiments, the insulating material provides electrical insulation to the anode and / or cathode. In some embodiments, the insulating material disposed on the coated electrode foil does not adhere or bond to the electrode film during the lamination process.

[0062] FIG. 1A shows a coating pattern of a coated electrode foil 100A according to some embodiments. The coated electrode foil 100A includes a third portion of a bare foil 101 (e.g., aluminum foil) and first portions 102a and 102b with a carbon coating. The coated electrode foil 100A is shown with the core ends 104a and 104b. FIG. 1B is an enlarged view of FIG. 1A showing a coating pattern of a coated electrode foil 100B. The coated electrode foil 100B includes a bare foil 101 (e.g., aluminum foil), first portions 102a and 102b with a carbon coating, and second portions 103a, 103b disposed between the first portion 102a and the bare foil 101 or between the first portion 102b and the bare foil 101, respectively. In some embodiments, the second portions 103a and 103b include an insulating material. In some embodiments, the coated electrode foil 100 may be cut along the location 103c to form a plurality of coated electrode foils. In some embodiments, an electrode film may be disposed over the first portion 102a and / or 102b and the carbon coating to form an electrode. In some embodiments, the electrode film is disposed over the first portion 102a and / or 102b and adheres to the carbon coating. In some embodiments, the electrode film is further disposed on the second portion 103a and / or 103b and the insulating layer. In some embodiments, the electrode film disposed on the second portion 103a and / or 103b and the insulating layer may be cleanly removed from the insulating layer without modifying or roughening the surface of the insulating layer. In some embodiments, the electrode film does not adhere to the insulating layer even after heat and / or pressure is applied.

[0063] Energy Storage Devices The energy storage device of the present disclosure includes an electrolyte, a cathode, an anode, and a housing as discussed herein, wherein the electrolyte, the cathode, and the anode are disposed within the housing. In some embodiments, the energy storage device provided herein is a lithium-ion battery. Each of the cathode and the anode includes an electrode film and a current collector that form an electrode.

[0064] FIG. 2A illustrates the battery cell 200 in a perspective view, and FIG. 2B illustrates the battery cell 200 in a side view. With joint reference to FIGS. 2A and 2B, the battery cell 200 may be any type of conventional battery cell capable of converting chemical energy of materials stored in the battery cell 200 into electrical energy. The battery cell 200 has a first end 202 and a second end 204. The battery cell 200 has a positive terminal 206 and a negative terminal 208 toward the first end 202. The positive terminal 206 preferentially protrudes from the first end 202 of the battery cell 200 to allow contact to the positive terminal 206, distinguishing the first end 202 from the second end 204, although different shapes of the positive terminal 206 may exist. The negative terminal 208 preferentially begins at the second end 204 and continues at an exterior surface 210 of the battery cell 200, covering at least a portion of the first end 202. The portion of the battery cell 200 that covers the outer surface to the first end may be referred to as the "shoulder" of the battery cell 200. The negative terminal 208 is preferentially formed on the shoulder, so that a connection to the negative terminal can be made at the shoulder. That is, the negative terminal 208 is preferentially present on the shoulder of the battery cell 200. An insulating region 212 may be provided on the surface 210 of the battery cell 200 to prevent the positive terminal 206 and the negative terminal 208 from shorting due to contact with each other. The insulating region 212 may be provided on the area of ​​the surface 210 between the positive terminal 206 and the negative terminal 208 via any other means. In an alternative embodiment, the positive and negative terminals may be switched.

[0065] As shown in FIG. 3, the jelly roll 300 includes a first substrate 302 having a first coating 310 disposed on one side of the first substrate 302. In some embodiments, the first coating 310 may be disposed on both sides of the first substrate 302 to form a bilayer electrode. In some embodiments, the first substrate 302 is preferably embodied in the form of a laminate having a thickness of a predetermined size, for example, within a range of 0.01 to 1 millimeter (mm). In some embodiments, the first substrate 302 comprises a current collector. In some embodiments, the current collector comprises a metal foil. In some embodiments, the current collector comprises aluminum or copper.

[0066] In some embodiments, the first coating 310 may be a conductive coating having a first magnitude of conductivity. In some embodiments, the first coating 310 comprises an electrode film and / or a conductive carbon coating. In some embodiments, the conductive coating comprises an electrode active material. In some embodiments, the conductive carbon coating is disposed over a current collector (e.g., an electrode foil). In some embodiments, the conductive carbon coating is disposed between the current collector and the electrode film, as described with respect to FIGS. 1A and 1B. In some embodiments, the electrode film is free-standing. In some embodiments, the electrode film is free of solvent residues. In some embodiments, the active layer or electrode film is free or substantially free of any processing additives, such as solvents and solvent residues resulting therefrom.

[0067] 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 is 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, depending on the method used, such an electrode film or active layer is strong enough to be used in the energy storage device manufacturing process without any external support elements such as current collectors, support webs or other structures, although support elements may be used to facilitate the energy storage device manufacturing process. For example, a "self-supporting" electrode film can have sufficient strength to be rolled, handled, and unrolled within the electrode manufacturing process without other support elements. A dry electrode film, such as a cathode electrode film or an anode electrode film, may be self-supporting.

[0068] As provided herein, a "solvent-free" electrode film is an electrode film that does not contain any detectable process solvent, process solvent residues, or process solvent impurities. A dry electrode film, such as a cathode electrode film or an anode electrode film made with only dry components, may be solvent-free.

[0069] A "wet" electrode, "wet-processed" electrode, or slurry electrode is an electrode or electrode film prepared by at least one step that includes a slurry of active material, binder, and optionally additives, even if a subsequent drying step removes moisture from the electrode or electrode film. Thus, a wet electrode or wet electrode film includes at least one or more processing solvents, processing solvent residues, and / or processing solvent impurities.

[0070] In some embodiments, the electrode film includes an active cathode material. In some embodiments, the electrode active material is selected from silicon materials (e.g., silicon metal and silicon dioxide), graphitic materials, graphite, graphene-containing materials, hard carbon, soft carbon, carbon nanotubes, porous carbon, and conductive carbon. In some embodiments, the cathode active material can include, 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 (e.g., LiCoO2 (LCO), Li(NiMnCo)O2 (NMC), and / or LiNi 0.8 Co 0.15 Al 0.05 O2(NCA)), spinel-type manganese oxide (LiMn2O4(LMO) and / or LiMn 1.5 Ni 0.5 The cathode active material may include, for example, lithium sulfide (Li2S), lithium sulph ...

[0071] In some embodiments, the electrode film includes an anode active material. In some embodiments, the anode active material can include, for example, an intercalation material (such as carbon, graphite, and / or graphene), an alloying / dealloying material (such as silicon, silicon oxide, tin, and / or tin oxide), a metal alloy or compound (such as Si-Al and / or Si-Sn), and / or a conversion material (such as manganese oxide, molybdenum oxide, nickel oxide, and / or copper oxide). The anode active materials can be used alone or mixed together to form a multiphase material (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-SnOx-C, Si-SiOx-Sn, or Sn-SiOx-SnOx, etc.). Anode active materials include common natural graphite, synthetic or artificial graphite, surface modified graphite, spherical graphite, flake graphite, and blends or combinations of these types of graphite, metallic elements and their compounds, and metal-C composites for the anode.

[0072] In some embodiments, the first coating further comprises a binder. In some embodiments, the first coating 310 may be disposed on the first substrate 302 by any means known to one of skill in the art. Some examples of disposing the first coating 310 on the first substrate 302 include, but are not limited to, mechanical deposition, electromechanical deposition, electrochemical deposition, or any combination of processes known to one of skill in the art.

[0073] A foil portion 312 of the first substrate 302 is formed midway through the width W of the first substrate 302 and includes an insulating layer 313 and a series of lower flags 316. In some embodiments, the insulating layer 313 includes a ceramic material and a binder as described herein. In some embodiments, the insulating layer 313 may be disposed on both sides of the first substrate 302. In some embodiments, the insulating layer 313 may help reduce or prevent electrical contact between the first substrate 302, first coating 310, and / or the series of lower flags 316 and the second substrate 306 and / or the second coating.

[0074] As shown, as the jellyroll is formed, the lower flag 316 becomes wrapped around the central axis AA'. In some embodiments, the lower flag 316 is an exposed area of ​​the first substrate 302 (e.g., a current collector). In some embodiments, the lower flag 316 consists or consists essentially of the first substrate 302. In some embodiments, as the electrode is wrapped to form the jellyroll, the series of flags are substantially interleaved such that they are substantially folded over one another and / or there is substantially no tenting of the flags. In some embodiments, the series of flags form a concentric circular pattern as the electrode is wrapped. In some embodiments, the distance between each of the series of flags is about 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm, or any range of values ​​therebetween. In some embodiments, for example, the distance between the series of flags is in the range of 5 mm to 50 mm. In a further embodiment, the distance between the series of flags is in the range of 5mm to 20mm.

[0075] An inner separator 304 is disposed over (e.g., stacked on) the first substrate 202. In some embodiments, the inner separator 304 is in the form of a laminate having a thickness of a predetermined magnitude, for example, in the range of 1 to 50 micrometers (μm). In some embodiments, the inner separator is or is about 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 15 μm, 20 μm, 30 μm, 40 μm, or 50 μm, or any range of values ​​therebetween (e.g., 5 to 10 μm). Further, in some embodiments, the inner separator 304 is electrically insulating. In some embodiments, the inner separator may comprise a polymeric material. In some embodiments, the inner separator may be selected from polyethylene, polypropylene, or a combination thereof. In some embodiments, the inner separator comprises multiple separator layers. In some embodiments, the inner separator comprises micropores.

[0076] A second substrate 306 is also disposed over the inner separator 304 (e.g., stacked on the inner separator 304). The second substrate 306 has a second coating 320 disposed on one side of the second substrate 306. In some embodiments, the second coating 320 may be disposed on both sides of the second substrate 306. In some embodiments, the second substrate 306 is in the form of a laminate having a thickness of a predetermined magnitude, for example, within a range of 0.01 to 1 millimeter (mm). In some embodiments, the second substrate 306 comprises a current collector (e.g., a foil).

[0077] The second coating 320 is a conductive coating having a second magnitude of conductivity. In some embodiments, the second coating 320 may be an electrode film and / or a conductive carbon coating. In some embodiments, the conductive coating includes an electrode active material. In some embodiments, the electrode active material is a cathodic active material. In some embodiments, the electrode active material is an anode active material. In certain embodiments, the second coating 320 may be similar or the same as the first coating 310 and therefore may have a similar or the same conductivity. In certain other embodiments, the second coating 320 may be different from the first coating 310 and therefore may have a different conductivity. In some embodiments, the second coating 320 may be disposed on the second substrate 306 by any means known to one of skill in the art. Some examples of disposing the second coating 320 on the second substrate 306 include, but are not limited to, mechanical deposition, electromechanical deposition, electrochemical deposition, or any combination of processes known to one of skill in the art.

[0078] The outer separator 308 may be disposed over the second substrate 306 (e.g., stacked on the second substrate 306). In some embodiments, the outer separator 308 is in the form of a laminate having a thickness of a predetermined size, for example, in the range of 1 to 50 μm. Furthermore, the outer separator 308 is electrically insulating. When the first substrate 302, the inner separator 304, the second substrate 306, and the outer separator 308 are sequentially stacked, the first substrate 302, the inner separator 304, the second substrate 306, and the outer separator 308 are wound around the central axis AA′ with the first substrate 302 closest to the central axis AA′.

[0079] As shown, the second substrate 306 includes a series of flags 306A formed from foil in communication with the second substrate 306. These flags 306A are wrapped around the top layer of the jelly roll to form a flower or artichoke shape when bent toward the central axis AA' as the jelly roll is formed. In some embodiments, the series of flags are substantially interleaved such that they are substantially folded over one another as the electrode is wrapped to form the jelly roll, and / or there is substantially no tenting of the flags. In some embodiments, each of the series of flags forms a concentric circular pattern as the electrode is wrapped. In some embodiments, the distance between the series of flags is about 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 21 mm, 22 mm, 23 mm, 24 mm, 25 mm, 26 mm, 27 mm, 28 mm, 29 mm, 30 mm, 31 mm, 32 mm, 33 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm, or any range of values ​​therebetween. In some embodiments, for example, the distance between the series of flags is in the range of 5 mm to 50 mm. In a further embodiment, the distance between the series of flags is in the range of 5mm to 20mm.

[0080] 4 shows a cross-sectional view of the end of a jelly roll 400, with an anode 410 separated from a cathode 412 by separators 401a and 401b. The anode 410 is shown as a dual-coated anode, including an anode current collector foil 403 sandwiched between anode conductive coatings 402a and 402b (e.g., a conductive carbon coating and an anode electrode film). The cathode 412 is shown as a dual-coated cathode, including a cathode current collector foil 405 sandwiched between cathode conductive coatings 404a and 404b (e.g., a conductive carbon coating and a cathode electrode film). An anode overhang 413 extends beyond the cathode 412. The cathode current collector 405 is shown extending beyond the distal ends of the cathode conductive coatings 404a and 404b, forming an extended overhang 406. A portion of the extended overhang 406 is coated with an insulating layer 407 to form a ceramic coating 415, and an exposed portion 416 of the extended overhang 406 forms a flag 408, with a portion of the flag bent over and beyond the separator overhang 414 and the distal ends of the separators 401a and 401b.

[0081] FIG. 5A shows an end of a payout electrode 500A with a flag 501, an insulating coating 502, and a conductive coating 503 (e.g., an electrode film and / or a conductive carbon coating). FIG. 5B shows an enlarged view of FIG. 5A showing an end of a payout electrode 500B with a flag 501, an insulating coating 502, and a conductive coating 503. According to one embodiment, the length of the ceramic material 502 measured between the flag 501 and the conductive coating 503 may be 2 mm, and the length of the series of flags 501 measured between the ceramic material 502 and the end of the flag may be 5.5 mm. The adhesiveness or substantial lack of adhesiveness of the insulating layer may allow the insulating layer to function as a patterning boundary to define a portion of the foil.

[0082] In some embodiments, the coated electrode foil includes a gap between the insulating layer and the electrode film, as shown in Figure 6. Figure 6 shows a cross-sectional view of a coating pattern of a double-sided coated electrode 600. The coated electrode 600 includes a current collector 601, a first portion 606 including top and bottom electrode films 604a and 604b, respectively, including top and bottom carbon coatings 602a and 602b, respectively, and partially disposed over the top and bottom carbon coatings 602a and 602b, and a second portion 607 including top and bottom insulating layers 603a and 603b, respectively. The coated electrode 600 also includes top and bottom gaps 605a, 605b disposed between edges of the top and bottom electrode films 604a, 604b and edges of the top and bottom insulating layers 603a, 603b. Gaps 605a and 605b are shown at the exposed portions of the top and bottom carbon coatings 602a and 602b. In some embodiments, there is no or substantially no intermixing of the insulating layers or ceramic coatings 603a and 603b with the electrode films or cathode electrodes 604a and 604b along the gaps 605.

[0083] The energy storage devices provided herein can be in any suitable form, for example, flat, spirally wound, button-shaped, or pouch. The energy storage devices provided herein can be components of a system, for example, a power generation system, an uninterruptible power system (UPS), a solar power generation system, an energy recovery system, for example, for use in industrial machinery and / or transportation. The energy storage devices provided herein may be used to power various electronic devices and / or automobiles, including hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), and / or electric vehicles (EVs).

[0084] It may be appreciated that the electrolyte formulations provided herein may be used in various embodiments with any of a number of energy storage devices and systems, such as one or more batteries, capacitors, capacitor-battery hybrids, fuel cells, or other energy storage systems or devices and combinations thereof. In some embodiments, the electrolyte additives or electrolytes including the additives described herein may be implemented in lithium ion batteries. Manufacturing method

[0085] Some embodiments of the present disclosure relate to a process for preparing the coated electrode foil and / or electrode disclosed herein. Figure 7 is a flow chart of a process 700 for preparing an electrode according to one embodiment. The process includes disposing 702 a carbon coating over a first portion of the foil and coating 704 a second portion of the foil with an insulating layer to form a coated electrode foil 706. Once the coated electrode foil is formed, an electrode film is disposed 708 over the coated electrode foil and over a portion of the insulating layer, and then the portion of the electrode film disposed over the insulating layer is removed 710 to form an electrode 712. In some embodiments, the portion of the insulating layer has a smooth surface after the portion of the electrode film is removed. In some embodiments, the portion of the electrode film peels cleanly from the insulating layer during the disposing and removing steps.

[0086] In some embodiments, a conductive coating and an insulating layer are coated side by side on a foil. A dry electrode film is then placed and laminated onto the conductive coating and insulating layer. The dry electrode adheres to the conductive coating but does not or does not substantially adhere to the insulating layer. The unadhered electrode portion is then cleanly peeled away and separated from the remainder of the adhered electrode, defining the edge of the electrode.

[0087] In some embodiments, the conductive coating and the insulating layer are coated side by side on the foil. A dry electrode film is then placed on top of the laminated conductive coating without overlapping the insulating layer. In some embodiments, the electrode film is cut to fit over the carbon coating and / or without overlapping the insulating layer. In some embodiments, as shown in FIG. 8, when the exposed portion of the conductive coating is located between the edge of the electrode and the edge of the insulating layer, there is a distance between the edge of the electrode and the edge of the insulating layer. FIG. 8 is a flow chart of a process 800 for preparing an electrode according to one embodiment. The process includes placing 802 a carbon coating over a first portion of a foil 802 and coating 804 a second portion of the foil with an insulating layer to form 806 a coated electrode foil. Once the coated electrode foil is formed 806, an electrode film is placed 808 over the first portion of the foil and over the carbon coating to form 810 an electrode.

[0088] In some embodiments, the ceramic coatings and dry electrode films utilized in the processes for preparing electrodes disclosed herein may utilize an aqueous insulating solution, and / or the insulating solution does not intermix with the dry electrode film. Intermixing may be avoided due to the use of a dry electrode film, removal of the electrode film from the insulating layer, and / or avoidance of placing the electrode film over an insulating layer, as described herein. In some embodiments, the process for avoiding intermixing includes the processes described herein with respect to Figures 7 and 8. In some embodiments, the electrodes for avoiding intermixing include the electrodes described herein with respect to Figures 1A-6.

[0089] In some embodiments, the electrode film is prepared by a dry electrode manufacturing process. As used herein, a dry electrode manufacturing process can refer to a process that forms a dry electrode film without or substantially without the use of a solvent. For example, the components of the active layer or electrode film, including the carbon material and the binder, can include, consist of, or consist essentially of dry particles. The dry particles for forming the active layer or electrode film can be combined to provide a dry particle active layer mixture. In some embodiments, the active layer or electrode film can be formed from a dry particle active layer mixture such that the weight percentages of the components of the active layer or electrode film and the weight percentages of the components of the dry particle active layer mixture are substantially the same. In some embodiments, the active layer or electrode film formed from the dry particle active layer mixture using a dry manufacturing process can be free or substantially free of any processing additives, such as solvents and solvent residues resulting therefrom. In some embodiments, the resulting active layer or electrode film is a self-supporting film formed from the dry particle mixture using a drying process. In some embodiments, the resulting active layer or electrode film is a free-standing film formed from the dry particle mixture using a drying process. The process for forming the active layer or electrode film may include fibrillating a fibrillizable binder component such that the film comprises a fibrillated binder. In further embodiments, a free-standing active layer or electrode film may be formed in the absence of a current collector. In yet other embodiments, the active layer or electrode film may comprise a fibrillated polymer matrix such that the film is self-supporting. It is believed that a matrix, lattice, or web of fibrils may be formed to provide mechanical structure to the electrode film.

[0090] In some embodiments, the electrode film mixture can be calendered in a calendering device to form a free-standing fibrillated electrode film. In some embodiments, the calendered mixture forms a free-standing dry particulate film that is free or substantially free of any liquids, solvents, and resulting residues therefrom. In some embodiments, the electrode film is an anode electrode film. In some embodiments, the electrode film is a cathode electrode film. In some embodiments, the process for manufacturing the electrode film is a dry process, in which no liquids or solvents are used and the listed raw materials are dry (e.g., one or more are dry powders), such that the resulting electrode film is free or substantially free of any liquids, solvents, and resulting residues.

[0091] In some embodiments, the insulating layer is applied to the metal current collector foil using a gravure coating method as a wet ink and dried. It has been found that for high speed gravure coating, the coating slurry must be adjusted to a specific viscosity. This requires a relatively low viscosity at high shear rates, but not too low to avoid bleeding. In some embodiments, the binder material comprises a polymer binder. In some embodiments, the binder material does not act as a hot melt lamination adhesive during the temperature range of the lamination process. In general, the coating slurry viscosity can be adjusted by reducing the solids and binder content, but lowering the amount of binder resulted in reduced coating properties. In some embodiments, the insulating layer wet ink comprises a solvent. In some embodiments, the solvent is an inorganic solvent, an organic solvent, or a combination thereof.

[0092] A typical wet-processed electrode utilizing a ceramic coating slurry and a cathode electrode slurry requires the use of the same solvent system, such as both solvent systems being organic solvent or both solvent systems being aqueous. In such wet-processed electrodes, the ceramic coating and cathode electrode slurries are deposited end-to-end, resulting in intermixing of the two slurries due to the similar solvent systems utilized. Furthermore, aqueous-based solvent systems for the insulating layer generally cannot be utilized in a typical wet-processed electrode, since slurry-cast electrode films generally require the use of organic solvents. The use of both aqueous-based and organic-based coatings in the same dryer can cause moisture to react with the cathode material, adversely affecting cathode activity. Additionally, edge-to-edge contact between the aqueous and organic-based coatings can cause gelling of the coatings, resulting in poor edge quality.

[0093] FIG. 9A is a scanning electron microscope (SEM) image of a typical wet-processed electrode utilizing an organic solvent system. As shown in FIG. 9A, the solvent-based ceramic slurry 901 mixes with the solvent-based cathode slurry 902, resulting in a wide overlap region 903 with overlap endpoints 903a and 903b. FIG. 9B is a top view photographic image of a typical wet-processed electrode. As visually shown in FIG. 9B, the overlap region of the two organic slurries covered a large area of ​​the wet-processed electrode, ultimately reducing the yield of the coated electrode prepared by wet processing.

[0094] In some embodiments, the energy storage device is fabricated such that one electrode (e.g., an anode) is larger than and overhangs the other electrode (e.g., a cathode). Such electrode overhangs can avoid yield loss. In some embodiments where there is no or substantially no overlap and / or intermingling of the insulating layer and the electrode film (e.g., a cathode electrode film), the boundaries of the electrode film are easier to identify, thus improving the ability to form a counter electrode (e.g., an anode electrode) with an overhang. In some embodiments, a vision system (e.g., a camera) can identify the boundaries of the electrode film and / or the amount of cathode material. EXAMPLES

[0095] The insulated electrode edge coating compositions of the present disclosure may be prepared utilizing the methods disclosed herein. Further embodiments are disclosed in more detail in the following examples, which are not intended to limit the scope of the claims in any way.

[0096] Example 1 - Preparation of formulation The formulation of the electrical insulating material of the present disclosure was prepared as follows: First, the ceramic powder was dispersed in water. Then, the binder resin and at least one crosslinking agent were added to the solution. The wetting agent and deionized water were added and mixed in a one-pot solution at low shear rate. Table 2 summarizes the manufacturing formulation of the electrical insulating material of the present disclosure. [Table 2]

[0097] Example 2 - Preparation of Binder Coupon Samples Binder coupon samples were prepared by drying the aqueous binder solutions in PTFE dishes. The non-crosslinked sample used neat Binder 1. The crosslinked sample used a 9:1 wt / wt mixture of Binder 1 and Binder 2. After the water was removed under vacuum at approximately 80°C, approximately 100 mg coupons of the dried binder film were cut and weighed on an analytical balance.

[0098] Example 3 - Binder ageing experiments in electrolyte A coupon sample prepared by the method of Example 2 was immersed in 20 mL of Li-ion battery electrolyte (approximately 1.2 m LiPF6 in EC:DMC:EMC (25:70:5) + 1% VC + 2% FEC) in a sealed polypropylene container. The top of the container was covered with parafilm and the container was stored in a dry room at 17°C to prevent water ingress.

[0099] The binder film was periodically removed from the electrolyte to measure the mass uptake of electrolyte by the film. Excess electrolyte was shaken off and unabsorbed / swollen electrolyte on the surface of the coupon was removed by Kimwipe. The film was weighed on an analytical balance to measure the mass gain from electrolyte uptake. All processes and handling of the film and electrolyte were carried out in a dry room. Measurement points were taken at 1, 2, 3, 6, 7, 8, 15, 41, 98, and 126 days.

[0100] Figure 10 summarizes the electrolyte uptake factors of aged electrolytes with crosslinked and non-crosslinked binders and demonstrates that the use of a crosslinked binder reduced electrolyte uptake compared to a non-crosslinked binder. For example, after 120 days, the electrolyte uptake factor of the aged electrolyte with a non-crosslinked binder was about 1.35, while the electrolyte uptake factor of the aged electrolyte with a crosslinked binder was about 1.25. Two samples of each film were tested.

[0101] Example 4 - Electrochemical stability of the binder Tests were performed using a typical formulation for ceramic coatings (e.g., 24 wt% ceramic and 2.4 wt% binder). For binder-only films, only the binder without ceramic was used. For crosslinked films, binder 2 was added at a 9:1 wt / w ratio (binder 1:binder 2). Films were directly coated onto Al foil, stainless steel disks, or onto stainless steel coin cell caps by doctor blade and dried in a vacuum oven. Film thickness was approximately 2 μm. Coin cells were constructed using the film (working electrode), polymer separator, lithium metal counter electrode, and standard electrolyte. Cells were tested for 20 cycles using cyclic voltammetry with a voltage window of 2.5-4.4 V vs. Li / Li+ and a voltage sweep rate of 0.5 mV / s. Stainless steel disks were utilized to reduce background signals typically generated from alloyed aluminum foils.

[0102] Figure 11 is a line graph showing the current vs. voltage of the electrode after 10 cycles. No significant electrochemical activity difference was observed over all cycles between all films, regardless of substrate, demonstrating the electrochemical stability of the crosslinked binder. Furthermore, no additional peaks were observed in this voltage range, again indicating the electrochemical stability of the binder and ceramic particles. The detected peaks may be related to the oxidation / reduction of FeF2 resulting from reaction with residual HF in the electrolyte.

[0103] Example 5 - Binder Differential Scanning Calorimetry (DSC) The binder films were dried in PTFE dishes under vacuum at 80°C. Crosslinked samples were prepared as above. Approximately 5-10 mg of solid binder was used for standard Differential Scanning Calorimetry (DSC) measurements. A TA Instruments Q50 DSC was utilized, sweeping from room temperature to 200°C, down to 0°C, and back to 200°C at 10°C / min.

[0104] FIG. 12 shows the DSC curves of the crosslinked and non-crosslinked binders. The crosslinked sample has a slightly lower T of about 160° C. gwhereas the uncrosslinked sample has a T of about 172 °C. g Approximately 0℃ to 30℃ T g Compared to typical water-based acrylate binders having such a high glass transition temperature, this allows for high temperature lamination processes by avoiding softening of the binder during coating, thus preventing sticking of the active material film.

[0105] Example 6 - Ceramic Interparticle Coagulation Ceramic inks were produced by a standard mixing process with various compositions. The total solids content of these inks was varied since the same inks were used to build the viscosity models. With regard to the dried coating properties, the total solids content utilized was found to be irrelevant since the defining property of coating strength is the amount of binder relative to ceramic. Here, the various films were coated on Al foils to a thickness of approximately 5 μm and dried overnight at 110 °C in a vacuum oven. The amount of binder was adjusted to 0-10% of the ceramic mass.

[0106] The coatings on the Al foil were applied to a steel block with strong double-sided tape. Cohesive strength was measured using 19 mm wide Scotch tape ("Velcro®"). The tape was applied by hand to the coating surface and pressure was applied to the tape via a rubber roller. The tape was peeled at a 180 degree angle at a speed of 12 inches / min via a standard peel test apparatus, an Instron load frame with a custom-made fixture. The peel force was measured by averaging the force required to peel the tape over a 15 second period. The tape was also qualitatively inspected to note whether any particles were visible on the tape after peeling.

[0107] Figure 13 is a graph of the cohesive strength of ceramic particles with various binders as a function of binder percentage. When the amount of binder was about 4% or less of the ceramic mass, particles were observed on the tape, and when the amount of binder was greater than 4% of the ceramic mass, the cohesive strength of the coating exceeded the adhesive strength of the individual particles to the tape.

[0108] Example 7 - Ceramic Coating Adhesion Adhesion was measured with a stronger adhesive backed tape (PSA). Adhesion strength was measured using the same 180 degree angle peel test with the same equipment and method as the adhesion measurement disclosed herein. After the coating was removed from the foil surface, the bare Al foil became visible, so the adhesive failure of the coating was visually observable. In this case, the thicker PSA of the tape can penetrate the surface of the coating and has a higher adhesiveness compared to the Scotch tape, causing the adhesive failure of the weaker coating with a lower binder amount.

[0109] FIG. 14 is a graph of the cohesive strength of the ceramic coating as a function of binder percentage. It was found that the morphology of the ceramic plays an important role in the adhesive strength of the coating. For example, Ceramic 1 failed at 7% ceramic weight binder. Ceramic 2 passed at 5% ceramic weight binder. Both of these ceramics have a similar particle size distribution, but Ceramic 2 is much more spherical than Ceramic 1. Without wishing to be bound by theory, it is believed that the spherical ceramics provide improved adhesive quality over non-spherical ceramics as a result of better packing of the ceramics causing a higher coating density.

[0110] Furthermore, when a standard acrylic binder with 5 wt. % ceramic was coated onto aluminum, the coating completely de-adhered from the foil surface, indicating that the insulating layer binder was superior to typical binders for separator ceramic coatings for adhesion onto aluminum foil.

[0111] As shown in Figures 15A-15C, typical insulating layers utilize large non-spherical particles with rough surfaces. In contrast, the insulating layers of the present disclosure utilize small spherical particles with smooth surfaces, as shown in Figures 15D-15F. Additionally, Figures 16A and 16B show scanning electron microscope (SEM) images of fully formulated coatings including Binder 1, Binder 2, and a ceramic material with a D50 particle size distribution of about 0.2 μm. Figures 17A and 17B show scanning electron microscope (SEM) images of fully formulated coatings including Binder 1, Binder 2, and a ceramic material with a D50 particle size distribution of about 0.3 μm. As shown in Figures 16A-16B and 17A-17B, fully formulated coatings with smooth surfaces have been prepared utilizing ceramic materials with a D50 particle size distribution of up to about 0.3 μm.

[0112] Importantly, during electrode fabrication, the edge coating insulating layer of the present disclosure peeled cleanly from the electrode active material layer. Figures 18A and 18B are images of lamination results utilizing an exemplary insulating layer. The exemplary insulating layer adhered to the coating and attached to the electrode active material layer during the application process. As a result, as seen in Figures 18A and 18B, the exemplary insulating layer did not peel cleanly from the electrode active material layer and therefore did not damage the electrode. In contrast, Figures 19A and 19B demonstrate that utilizing the insulating layer of the present disclosure does not adhere to the coating and peels cleanly from the electrode active material layer during the application process. Thus, the insulating layer of the present disclosure did not damage the electrode as seen in Figures 19A and 19B.

[0113] Furthermore, the addition of 2 wt. % ammonium polyacrylate as a dispersant to the insulating layer composition of the present disclosure was found to deteriorate lamination, as seen in Figure 20. Also, the addition of an unknown dispersant to the same ceramics from the same supplier resulted in failure of electrode fabrication, suggesting that the low glass transition temperature of polyacrylate may cause the electrode to stick to the insulating layer.

[0114] Example 8 - Gap formation between insulating layer and electrode film A cathode coated electrode was prepared by a process similar to that described in Figure 8 by disposing a carbon coating on a first portion of an aluminum foil and coating the foil with an insulating layer on a second portion of the foil. An electrode film was disposed on the first portion of the foil and the carbon coating to form a coated electrode with a gap disposed between the electrode film and the second portion of the foil. The cathode was composed of an active material (e.g., NMC, NCA), a carbon material, and a binder.

[0115] Figure 21A is a photographic top view of a coated cathode electrode having a gap between the electrode film and the insulating layer, and Figure 21B is an enlarged view of Figure 21A. As shown in Figures 21A and 21B, the gap between the electrode film and the insulating layer where the carbon coating is present is visible. Such visual gaps can be easily identified by a vision system, thereby facilitating the fabrication of complementary anode electrodes and / or anode electrode films having an overhang beyond the edges of the cathode electrode film.

[0116] Although specific embodiments have been described, these embodiments are presented by way of example 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 of the systems and methods 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.

[0117] It is to be understood that features, materials, properties, or groups described in connection with a particular aspect, embodiment, or example are applicable to any other aspect, embodiment, or example described in this section or elsewhere in this specification, unless inconsistent therewith. All of the features disclosed in this specification (including the accompanying claims, abstract, and drawings), and / or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations in which at least some of such features and / or steps are mutually exclusive. Protection is not limited to the details of any of the foregoing embodiments. Protection extends to any novel or any novel combination of features disclosed in this specification (including the accompanying claims, abstract, and drawings), or any novel or any novel combination of steps of any method or process so disclosed.

[0118] Moreover, certain features that are described in this disclosure in the context of separate implementations can also be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation can also be implemented separately in multiple implementations or in any suitable subcombination. Furthermore, although features may be described above as acting in a particular combination, one or more features from the claimed combination can, in some cases, be deleted from the combination, and the combination can be claimed as a subcombination or a variation of the subcombination.

[0119] Furthermore, although operations may be depicted in the figures or described in the specification in a particular order, such operations need not be performed in the particular order shown or in sequential order to achieve desired results, nor need all operations be performed. Other operations not shown or described can be incorporated into the example methods and processes. For example, one or more additional operations can be performed before, after, simultaneously with, or between any of the described operations. Furthermore, operations may be rearranged or reordered in other implementations. As will be appreciated by those skilled in the art, in some embodiments, the actual steps performed in the illustrated and / or disclosed processes may differ from those shown in the figures. Depending on the embodiment, certain of the steps described above may be omitted and other steps may be added. Furthermore, the features and attributes of certain embodiments disclosed above may be combined in different ways to form further embodiments, all of which are within the scope of the present disclosure. Additionally, the separation of various system components in the above implementations should not be understood to require such separation in all implementations, and it should be understood that the described components and systems can generally be incorporated together in 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 integrated with one another (e.g., packaged together or attached to one another) to form an energy storage system.

[0120] 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 of ordinary skill in the art will recognize that the present disclosure may be embodied or implemented to obtain one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

[0121] The headings provided herein, if any, are for convenience only and do not necessarily affect the scope or meaning of the devices and methods disclosed herein.

[0122] 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 presented in this section or elsewhere herein, or as presented in the future. The language of the claims should be interpreted broadly based on the language used in the claims, and not limited to the examples or during the prosecution of the application described herein, and the examples should be interpreted as non-exclusive.

Claims

1. a foil comprising a first portion, a second portion, and a third portion; a carbon coating disposed over the first portion of the foil; and an insulating layer disposed over the second portion of the foil; The insulating layer comprises: a ceramic material comprising a D50 particle size distribution range of 1 nm to 500 nm; a high glass transition temperature binder; A coated electrode foil comprising:

2. 2. Coated foil according to claim 1, wherein said high glass transition temperature binder has a glass transition temperature of at least 140°C.

3. 2. The coated foil of claim 1, wherein the ceramic material comprises a powder selected from the group consisting of alumina powder, boehmite powder, and combinations thereof.

4. 2. The coated foil of claim 1, wherein the ceramic material comprises a D50 particle size distribution range of 0.1 μm to 0.3 μm.

5. 2. The coated foil of claim 1, wherein the binder comprises at least one of polyvinylpyrrolidone (PVP), poly(N-vinylcaprolactam) (PNVCL), poly(vinylpyrrolidone-co-caprolactam), poly(n-vinylacetamide) (PNVA), ethylene-acrylic acid (EAA), or polyglycidyl ether.

6. The coated electrode foil according to any one of claims 1 to 5, an electrode film disposed over the first portion of the foil; An electrode comprising:

7. The electrode of claim 6 , wherein the third portion of the coated electrode foil comprises a series of flags.

8. The electrode of claim 7 , wherein the electrode is in a wound configuration and the series of flags are substantially interleaved.

9. The electrode of claim 7 , wherein the series of flags form a concentric circular pattern.

10. 8. The electrode of claim 7, wherein the distance between the series of flags is in the range of 5 mm to 50 mm.

11. 11. The electrode of claim 10, wherein the distance between the series of flags is in the range of 5 mm to 20 mm.

12. The electrode of claim 6 , further comprising a gap disposed between the electrode film and the insulating layer.

13. The electrode according to claim 6; a second electrode; and a separator disposed between the electrode and the second electrode; Electrolytes, a housing, the electrode, the second electrode, the separator, and the electrolyte being disposed within the housing; and An energy storage device comprising:

14. 14. The cell of claim 13, wherein the electrode is a cathode and the second electrode is an anode.

15. 1. A method for preparing an electrode, comprising: coating a foil having a first portion and a second portion with an insulating layer over the second portion to form a coated electrode foil, wherein a carbon coating is disposed over the first portion of the foil; disposing an electrode film over the coated electrode foil, a portion of the electrode film being disposed over the insulating layer; removing the portion of the electrode film disposed over the insulating layer to form an electrode; A method comprising:

16. The method of claim 15 , wherein the portion of the insulating layer comprises a smooth surface after the portion of the electrode film is removed.

17. 16. The method of claim 15, wherein the portion of the electrode film peels cleanly from the insulating layer during the disposing and removing steps.

18. 18. The method of claim 15, further comprising visually identifying a boundary of the electrode film and forming a counter electrode with an overhang extending beyond the electrode.

19. A ceramic material comprising a D50 particle size distribution range of 1 nm to 500 nm; a high glass transition temperature binder; An insulating material comprising:

20. 20. The insulating material of claim 19, wherein the ceramic material comprises a D50 particle size distribution range of 0.1 μm to 0.3 μm.

21. 1. A method for preparing an electrode, comprising: coating a foil having a first portion and a second portion with an insulating layer over the second portion to form a coated electrode foil, wherein a carbon coating is disposed over the first portion of the foil; disposing an electrode film over the first portion of the foil and over the carbon coating to form an electrode; A method comprising:

22. 22. The method of claim 21, further comprising cutting the electrode film before disposing the electrode film over the first portion of the foil and over the carbon coating.

23. 22. The method of claim 21, wherein said step of coating said foil comprises disposing an aqueous insulating solution over said second portion.

24. 24. The method of any one of claims 21 to 23, further comprising forming a gap disposed between the electrode film and the second portion.

25. 25. The method of claim 24, further comprising identifying the gap and forming a counter electrode having an overhang extending beyond the electrode.

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