Dielectric polymer films

Abstract

Thin polymer films may comprise a first polymer layer comprising poly(vinylidene fluoride); a second polymer layer comprising poly(vinylidene fluoride); and a nanofiller-polymer layer interposed between the first polymer layer and the second polymer layer, the nanofiller-polymer layer comprising poly(methyl methacrylate) and nanosheets dispersed in the poly(methyl methacrylate); the nanosheets comprising mica nanosheets and / or hexagonal boron-nitride nanosheets; wherein 50-99% of the nanosheets in the nanofiller-polymer layer are oriented parallel to a width dimension of the first polymer layer.

Description

DIELECTRIC POLYMER FILMSSTATEMENT OF GOVERNMENT INTEREST

[0001] This invention was made with government support under grant number NSF-DMR- 1900692 awarded by the National Science Foundation. The government has certain rights in the invention.TECHNICAL FIELD

[0002] The present disclosure relates to thin polymer films and dielectric capacitors comprising the same. Thin polymer films disclosed and contemplated herein comprise a first polymer layer, a second polymer layer and a nanofiller-polymer layer interposed between the first polymer layer and the second polymer layer.INTRODUCTION

[0003] High energy density and high-power density energy storage dielectric capacitors may play an important role in enabling reliable power supply as decarbonization drives the world to shift towards intermittent renewable energy sources. However, the energy density of existing dielectric capacitors remains limited as compared to their electrochemical counterparts.SUMMARY

[0004] In one aspect, a thin polymer film is disclosed. Exemplary thin polymer films may comprise a first polymer layer comprising poly(vinylidene fluoride); a second polymer layer comprising poly(vinylidene fluoride); and a nanofiller-polymer layer interposed between the first polymer layer and the second polymer layer. The nanofiller-polymer layer may comprise poly(methyl methacrylate) and nanosheets dispersed in the poly(methyl methacrylate). The nanosheets may comprise mica nanosheets and / or hexagonal boron-nitride nanosheets. In various instances, 50-99% of the nanosheets in the nanofiller-polymer layer may be oriented parallel to a width dimension of the first polymer layer.

[0005] The thin polymer film has a thickness of 300 nm to 15 pm. The first polymer layer may have a thickness of 100 nm to 5 pm. The second polymer layer may have a thickness of 100 nm to 5 pm. The nanofiller-polymer layer may have a thickness of 100 nm to 5 pm. The nanosheetsmay have an average thickness of 1 nm to 50 nm. The nanofiller-polymer layer may have an area of 0.01 pm2to 1000 gm2. The nanosheets may cover at least 50% of the area of the nanofiller- polymer layer. The nanosheets may be present in the nanofiller-polymer layer at about 0.1% to 5% by volume.

[0006] In another aspect, a dielectric capacitor is disclosed. The dielectric capacitor may comprise a first electrode substrate; a second electrode substrate; and a thin polymer film. The first polymer layer may be positioned on the first electrode substrate, and the second electrode substrate is positioned on the second polymer layer. The dielectric capacitor may have a dielectric constant (e) of 19 to 22 at room temperature. The dielectric capacitor may have a dielectric strength (EBD) of greater than 1000 megavolts per meter (MV / m). The dielectric capacitor may have a capacitive discharge energy density (UD) of at least 50 J / cm3.

[0007] In another aspect, an energy storage device is disclosed. The energy storage device may comprise a dielectric capacitor.

[0008] In another aspect, a method of manufacturing a thin polymer film is disclosed. The method may comprise preparing a poly(methyl methacrylate) solution comprising a first solvent and poly methyl methacrylate); providing an array of nanosheets comprising mica nanosheets and / or hexagonal boron-nitride nanosheets; spin coating the poly(methyl methacrylate) solution onto the array of nanosheets to provide the nanofiller-polymer layer; annealing the nanofiller- polymer layer; preparing a poly(vinylidene fluoride) solution comprising a second solvent and poly(vinylidene fluoride); providing the first polymer layer positioned on a substrate; depositing the nanofiller-polymer layer onto the first polymer layer; drying the nanofiller-polymer layer deposited on the first polymer layer; and spin coating the poly(vinylidene fluoride) solution onto the nanofiller-polymer layer to provide the second polymer layer. Before providing the array of nanosheets, the nanosheets may be mechanically exfoliated.

[0009] Before any embodiments of the disclosure are explained in detail, it is to be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 schematically illustrates a side view of an exemplary thin polymer film.

[0011] FIG. 2 schematically illustrates an exploded perspective view of an exemplary dielectric capacitor.

[0012] FIG. 3 shows a flowchart of an exemplary method for preparing exemplary thin polymer films.

[0013] FIG. 4A is a microscope image of exfoliated mica flakes on a first area of an experimentally generated Si / SiC>2 substrate.

[0014] FIG. 4B is a microscope image of exfoliated mica flakes on a second area of the experimentally generated Si / SiC>2 substrate shown in FIG. 4A.

[0015] FIG. 4C is a microscope image of exfoliated mica flakes on a third area of the experimentally generated Si / SiC>2 substrate shown in FIG. 4A.

[0016] FIG. 4D is a microscope image of exfoliated mica flakes on a fourth area of a Si / SiCh substrate shown in FIG. 4A.

[0017] FIG. 5 schematically illustrates the experimental method used to prepare experimentally generated PVDF / 2D Mica-PMMA / PVDF (Mica interfaced) heterostructure capacitors.

[0018] FIG. 6A graphically shows the temperature (7) dependent dielectric constants (s) of experimentally generated PVDF / PMMA / PVDF (reference) and PVDF / 2D Mica-PMMA / PVDF (Mica interfaced) heterostructure capacitors respectively.

[0019] FIG. 6B graphically shows the frequency (Hz) dependent dielectric constants (E) of experimentally generated PVDF / PMMA / PVDF (reference) and PVDF / 2D Mica-PMMA / PVDF (Mica interfaced) heterostructure capacitors respectively.

[0020] FIG. 6C graphically shows the enhancement in E ( ls) of the PVDF / 2D Mica- PMMA / PVDF (Mica interfaced) heterostructure capacitor compared to the PVDF / PMMA / PVDF heterostructure (reference) capacitor as a function of frequency.

[0021] FIG. 6D graphically shows the dielectric loss for PVDF / PMMA / PVDF heterostructure (reference) capacitors.

[0022] FIG. 6E graphically shows the dielectric loss for experimentally generated PVDF / 2D Mica-PMMA / PVDF (Mica interfaced) heterostructure capacitors.

[0023] FIG. 6F schematically illustrates the origins of higher dielectric constant due to higher nanofiller-polymer interfacial polarization.

[0024] FIG. 7A is a schematic demonstrating electrical tree propagation in polymeric heterostructures.

[0025] FIG. 7B is a schematic demonstrating enhanced resistance to electrical tree propagation by oriented 2D mica nanosheets in polymeric heterostructures.

[0026] FIG. 8 graphically shows two-parameter Weibull probability plots and fits of experimentally generated PVDF / PMMA / PVDF and PVDF / PMMA-2D Mica / PVDF heterostructures measured at room temperature.

[0027] FIG. 9A graphically shows electric displacement vs electric field of experimentally generated PVDF / PMMA / PVDF and PVDF / PMMA-2D Mica / PVDF heterostructures.

[0028] FIG. 9B graphically shows discharge energy density and efficiency of experimentally generated PVDF / PMMA / PVDF and PVDF / PMMA-2D Mica / PVDF heterostructures.

[0029] FIG. 10A graphically shows discharge energy density and efficiency for experimentally generated capacitors, made from oriented 2D Mica nanofdlers in the experimental examples, with the pristine polymeric and nanocomposites-based capacitors demonstrated in the literature.

[0030] FIG. 10B graphically shows discharge energy density and maximum electric field for experimentally generated capacitors, made from oriented 2D Mica nanofillers in the experimental examples, with the pristine polymeric and nanocomposites-based capacitors demonstrated in the literature.

[0031] FIG. 11 graphically shows the permittivity enhancement (Ae) in experimentally generated PVDF / PMMA- / ?-BN / PVDF heterostructures as compared to PVDF / PMMA / PVDF control heterostructures.

[0032] FIG. 12 graphically shows the Weibull probability plots of experimentally generated PVDF / PMMA / PVDF and P VDF / PMM A-Zr-BN / P VDF heterostructures.

[0033] FIG. 13 A graphically shows electric displacement vs electric field of experimentally generated pristine and Z?-BN based heterostructures.

[0034] FIG. 13B graphically shows discharge energy density and efficiency of experimentally generated pristine and Z / -BN based heterostructures.DETAILED DESCRIPTION

[0035] Exemplary materials, methods and techniques disclosed and contemplated herein generally relate to thin polymer films. Exemplary thin polymer films disclosed and contemplated herein may be incorporated into dielectric capacitors.I. Definitions

[0036] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. In case of conflict, the present document, including definitions, will control. Methods and materials are described below, although methods and materials similar or equivalent to those described herein can be used in practice or testing of the present disclosure. All publications, patent applications, patents and other references mentioned herein are incorporated by reference in their entirety. The materials, methods, and examples disclosed herein are illustrative only and not intended to be limiting.

[0037] The terms “comprise(s),” “include(s),” “having,” “has,” “can,” “contain(s),” and variants thereof, as used herein, are intended to be open-ended transitional phrases, terms, or words that do not preclude the possibility of additional acts or structures. The singular forms “a,” “an” and “the” include plural references unless the context clearly dictates otherwise. The present disclosure also contemplates other embodiments “comprising,” “consisting of’ and “consisting essentially of,” the embodiments or elements presented herein, whether explicitly set forth or not.

[0038] As used herein, the term “about” is used to indicate that exact values are not necessarily attainable. Therefore, the term “about” is used to indicate this uncertainty limit. The term “about” may refer to plus or minus 10% of the indicated number. For example, “about 10%” may indicate a range of 9% to 11%, and “about 1” may mean from 0.9-1.1. Other meanings of “about” may be apparent from the context, such as rounding off, so, for example “about 1” may also mean from 0.5-1.4. The modifier “about” should also be considered as disclosing the range defined by the absolute values of the two endpoints. For example, the expression “from about 2 to about 4” also discloses the range “from 2 to 4.”

[0039] For the recitation of numeric ranges herein, each intervening number there between with the same degree of precision is contemplated. For example, for the range of 6-9, the numbers 7 and 8 are contemplated in addition to 6 and 9, and for the range 6.0-7.0, the numbers 6.0, 6.1, 6.2,6.3, 6.4, 6.5, 6.6, 6.7, 6.8, 6.9, and 7.0 are contemplated. For another example, when a pressure range is described as being between ambient pressure and another pressure, a pressure that is ambient pressure is expressly contemplated.IL Exemplary Thin Polymer Films

[0040] FIG. 1 schematically depicts a side view of an exemplary thin polymer film 100. As shown in FIG. 1, exemplary thin polymer film 100 may comprise a first polymer layer 102, a second polymer layer 104, and a nanofiller-polymer layer 106. As shown, the nanofiller-polymer layer 106 is interposed between the first polymer layer 102 and the second polymer layer 104. In various instances, one surface of the nanofiller-polymer layer 106 is contacting the first polymer layer 102 and an opposite surface of the nanofiller-polymer layer 106 is contacting the second polymer layer 104.

[0041] In various instances, exemplary thin film polymers 100 may have a thickness TPF of 300 nm to 15 pm. In some instances, exemplary thin film polymers 100 may have a thickness TPFof 300 nm to 14 pm; 350 nm to 12 pm; 400 to 10 pm; 400 nm to 8 pm; 450 nm to 6 pm; 500 nm to 5 pm; 550 nm to 4 pm; 600 nm to 3 pm; 650 nm to 2 pm; 700 nm to 1 pm; 750 nm to 950 nm; or 800 nm to 900 nm. In various instances, exemplary thin film polymers 100 may have a thickness TPF of no greater than 15 pm; no greater than 14 pm; no greater than 12 pm; no greater than 10 pm; no greater than 8 pm; no greater than 6 pm; no greater than 5 pm; no greater than 4 pm; no greater than 3 pm; no greater than 2 pm; no greater than 1 pm; no greater than 950 nm; no greater than 900 nm; no greater than 850 nm; no greater than 800 nm; no greater than 750 nm; no greater than 700 nm; no greater than 650 nm; no greater than 600 nm; no greater than 550 nm; no greater than 500 nm; or no greater than 450 nm. In various instances, exemplary thin film polymers 100 may have a thickness TPFof no less than 400 nm; no less than 450 nm; no less than 500 nm; no less than 550 nm; no less than 600 nm; no less no less than 650 nm; no less than 700 nm; no less than 750 nm; no less than 800 nm; no less than 850 nm; no less than 900 nm; no less than 950 nm; no less than 1 pm; no less than 2 pm; no less than 3 pm; no less than 4 pm; no less than 5 pm; no less than 6 pm; no less than 8 pm; no less than 10 pm; no less than 12 pm; or no less than 14 pm.A. Exemplary First Polymer Layers

[0042] Exemplary first polymer layers 102 may comprise one or more dielectric polymers. The dielectric polymer may vary depending on the specific implementation. Exemplary dielectric polymers may include poly(vinylidene fluoride) (PVDF), polypropylene (PP), polyethylene (PE), a polystyrene, a polycarbonate, a polyimide, a polyacrylate, a polysulfone, a polyurethane, a cellulose, and combinations thereof. The term “dielectric polymer,” as used herein, means a polymer which can resist the flow of electrical current and has low loss of energy under an applied electric field. In various instances, exemplary first polymer layers 102 may comprise poly(vinylidene fluoride) (PVDF).

[0043] In various instances, exemplary first polymer layers 102 may have a thickness Tn of 100 nm to 5 pm. In some instances, exemplary first polymer layers 102 may have a thickness TLI of 150 nm to 4.5 pm; 200 nm to 4 pm; 350 nm to 3.5 pm; 400 nm to 3 pm; 450 nm to 2.5 pm; 500 nm to 2 pm; 550 nm to 1.5 pm; 600 nm to 1 pm; 650 nm to 950 nm; 700 nm to 900 nm; or 750 nm to 800 nm. In various instances, exemplary first polymer layers 102 may have a thickness TLI of no greater than 5 pm; no greater than 4 pm; no greater than 3 pm; no greater than 2 pm; no greater than 1 pm; no greater than 900 nm; no greater than 800 nm; no greater than 700 nm; no greater than 600 nm; no greater than 500 nm; no greater than 400 nm; no greater than 300 nm; or no greater than 200 nm. In various instances, exemplary first polymer layers 102 may have a thickness Tn of no less than 100 nm; no less than 200 nm; no less than 300 nm; no less than 400 nm; no less than 500 nm; no less than 600 nm; no less than 700 nm; no less than 800 nm; no less than 900 nm; no less than 1 pm; no less than 2 pm; no less than 3 pm; or no less than 4 pm.B. Exemplary Second Polymer Layers

[0044] Exemplary second polymer layers 104 may comprise one or more dielectric polymers. The dielectric polymer may vary depending on the specific implementation. Exemplary dielectric polymers may include poly(vinylidene fluoride) (PVDF), polypropylene (PP), polyethylene (PE), a polystyrene, a polycarbonate, a polyimide, a polyacrylate, a polysulfone, a polyurethane, a cellulose, and combinations thereof. In various instances, exemplary second polymer layers 104 may comprise poly(vinylidene fluoride) (PVDF).

[0045] Tn various instances, exemplary second polymer layers 104 may have a thickness TL2 of 100 nm to 5 pm. In some instances, exemplary second polymer layers 104 may have a thickness TL2 of 150 nm to 4.5 pm; 200 nm to 4 pm; 350 nm to 3.5 pm; 400 nm to 3 pm; 450 nm to 2.5 pm; 500 nm to 2 pm; 550 nm to 1.5 pm; 600 nm to 1 pm; 650 nm to 950 nm; 700 nm to 900 nm; or 750 nm to 800 nm. In various instances, exemplary second polymer layers 104 may have a thickness TL2 of no greater than 5 pm; no greater than 4 pm; no greater than 3 pm; no greater than 2 pm; no greater than 1 pm; no greater than 900 nm; no greater than 800 nm; no greater than 700 nm; no greater than 600 nm; no greater than 500 nm; no greater than 400 nm; no greater than 300 nm; or no greater than 200 nm. In various instances, exemplary second polymer layers 104 may have a thickness TL2 of no less than 100 nm; no less than 200 nm; no less than 300 nm; no less than 400 nm; no less than 500 nm; no less than 600 nm; no less than 700 nm; no less than 800 nm; no less than 900 nm; no less than 1 pm; no less than 2 pm; no less than 3 pm; or no less than 4 pm.C. Exemplary Nanofiller-Polymer Layers

[0046] Exemplary nanofdler-polymer layers 106 may comprise a polymer 106a and nanosheets 1066 dispersed in the polymer 106a. Exemplary polymers 106a may comprise one or more dielectric polymers, such as poly(vinylidene fluoride) (PVDF), polypropylene (PP), polyethylene (PE), polystyrene, a polycarbonate, a polyimides, a polyacrylate, a polysulfone, a polyurethane, and / or a cellulose. The dielectric polymer may vary depending on the specific implementation. In various instances, exemplary polymers 106a may comprise poly(methyl methacrylate). Exemplary nanosheets 106Z> may comprise mica nanosheets, hexagonal or amorphous boron-nitride nanosheets, graphene oxide, MXenes, nanoclays, and / or transition metal dichalcogenides. The term “MXene,” as used herein, refers to a two-dimensional inorganic compound consisting of atomically thin layers of transition metal carbides, nitrides, and / or carbonitrides. In various instances, exemplary nanosheets 106Z> may comprise mica nanosheets and / or hexagonal boronnitride nanosheets.

[0047] In various instances, exemplary nanofiller-polymer layers 106 may have a thickness TNP of 100 nm to 5 pm. In some instances, exemplary nanofiller-polymer layers 106 may have a thickness TNP of 150 nm to 4.5 pm; 200 nm to 4 pm; 350 nm to 3.5 pm; 400 nm to 3 pm; 450 nmto 2.5 pm; 500 nm to 2 pm; 550 nm to 1.5 pm; 600 nm to 1 pm; 650 nm to 950 nm; 700 nm to 900 nm; or 750 nm to 800 nm. In various instances, exemplary nanofiller-polymer layers 106 may have a thickness Tw of no greater than 5 pm; no greater than 4 pm; no greater than 3 pm; no greater than 2 pm; no greater than 1 pm; no greater than 900 nm; no greater than 800 nm; no greater than 700 nm; no greater than 600 nm; no greater than 500 nm; no greater than 400 nm; no greater than 300 nm; or no greater than 200 nm. In various instances, exemplary nanofiller- polymer layers 106 may have a thickness T-.(, of no less than 100 nm; no less than 200 nm; no less than 300 nm; no less than 400 nm; no less than 500 nm; no less than 600 nm; no less than 700 nm; no less than 800 nm; no less than 900 nm; no less than 1 pm; no less than 2 pm; no less than 3 pm; or no less than 4 pm.

[0048] In various instances, exemplary nanofiller-polymer layers 106 may have an area of 0.01 pm2to 1000 pm2. In some instances, exemplary nanofiller-polymer layers 106 may have an area of 0.1 pm2to 900 pm2; 0.2 pm2to 800 pm2; 0.3 pm2to 700 pm2; 0.4 pm2to 600 pm2; 0.5 pm2to 500 pm2; 0.6 pm2to 400 pm2; 0.7 pm2to 300 pm2; 0.8 pm2to 200 pm2; 0.9 pm2to 190 pm2; 1 pm2to 100 pm2; 5 pm2to 95 pm2; 10 pm2to 90 pm2; 15 pm2to 85 pm2; 20 pm2to 80 pm2; 25 pm2to 75 pm2; 30 pm2to 70 pm2; 35 pm2to 65 pm2; 40 pm2to 60 pm2; or 45 pm2to 55 pm2. In various instances, exemplary nanofiller-polymer layers 106 may have an area of no greater than 1000 pm2; no greater than 900 pm2; no greater than 800 pm2; no greater than 700 pm2; no greater than 600 pm2; no greater than 500 pm2; no greater than 400 pm2; no greater than 300 pm2; no greater than 200 pm2; no greater than 100 pm2; no greater than 90 pm2; no greater than 80 pm2; no greater than 70 pm2; no greater than 60 pm2; no greater than 50 pm2; no greater than 40 pm2; no greater than 30 pm2; no greater than 20 pm2; no greater than 10 pm2; no greater than 5 pm2; no greater than 1 pm2; no greater than 0.5 pm2; no greater than 0.1 pm2; or no greater than 0.05 pm2. In various instances, exemplary nanofiller-polymer layers 106 may have an area of no less than 0.01 pm2; no less than 0.05 pm2; no less than 0.1 pm2; no less than 0.5 pm2; no less than 1 pm2; no less than 5 pm2; no less than 10 pm2; no less than 20 pm2; no less than 30 pm2; no less than 40 pm2; no less than 50 pm2; no less than 60 pm2; no less than 70 pm2; no less than 80 pm2; no less than 90 pm2; no less than 100 pm2; no less than 200 pm2; no less than 300 pm2; no less than 400 pm2; no less than 500 pm2; no less than 600 pm2; no less than 700 pm2; no less than 800 pm2; or no less than 900 pm2.

[0049] In various instances, exemplary nanosheets 106b may have an average thickness TNs of 1 nm to 50 nm. In some instances, exemplary nanosheets 106b may have an average thickness 7% of 1.5 nm to 45 nm; 2 nm to 40 nm; 2.5 nm to 35 nm; 3 nm to 30 nm; 3.5 nm to 25 nm; 4 nm to 20 nm; 4.5 nm to 15 nm; 5 nm to 10 nm; 6 nm to 9 nm; or 7 nm to 8 nm. In various instances, exemplary nanosheets 106b may have an average thickness TNs of no greater than 50 nm; no greater than 40 nm; no greater than 30 nm; no greater than 20 nm; no greater than 15 nm; no greater than 10 nm; no greater than 5 nm; no greater than 4 nm; no greater than 3 nm; or no greater than 2 nm. In various instances, exemplary nanosheets 106 / ? may have an average thickness TNs of no less than 1 nm; no less than 2 nm; no less than 3 nm; no less than 4 nm; no less than 5 nm; no less than 10 nm; no less than 15 nm; no less than 20 nm; no less than 30 nm; or no less than 40 nm.

[0050] In various instances, 50-99% of the nanosheets 106b in the nanofiller-polymer layer 106 may be oriented parallel to a width dimension WLI of the first polymer layer 102, as schematically depicted in FIG. 1. In various instances, 55-95%; 60-90%; 65-85%; or 70-80% of the nanosheets 106b in the nanofiller-polymer layer 106 may be oriented parallel to a width dimension WLI of the first polymer layer 102. In various instances, no greater than 99%; no greater than 95%; no greater than 90%; no greater than 85%; no greater than 80%; no greater than 75%; no greater than 70%; no greater than 65%; no greater than 60%; or no greater than 55% of the nanosheets 106 / > in the nanofiller-polymer layer 106 may be oriented parallel to a width dimension WLI of the first polymer layer 102. In various instances, no less than 50%; no less than 55%; no less than 60%; no less than 65%; no less than 70%; no less than 75%; no less than 80%; no less than 85%; no less than 90%; or no less than 95% of the nanosheets 106 / > in the nanofiller-polymer layer 106 may be oriented parallel to a width dimension WLI of the first polymer layer 102.

[0051] In various instances, the nanosheets 106b may cover at least 50% of the area of the nanofiller-polymer layer 106. In some instances, the nanosheets 106Z> may cover at least 55%; at least 60%; at least 65%; at least 70%; at least 75%; at least 80%; at least 85%; at least 90%; or at least 95% of the area of the nanofiller-polymer layer 106.

[0052] In various instances, the nanosheets 106Z> may be present in the nanofiller-polymer layer 106 at about 0.1% to 5% by volume (vol%). In some instances, the nanosheets 106b may be present in the nanofiller-polymer layer 106 at about 0.15 to 4.5 vol%; about 0.2 to 4 vol%; about 0.25 to 3.5 vol%; about 0.3 to 3 vol%; about 0.35 to 2.5 vol%; about 0.4 to 2 vol%; about 0.45 to 1.5vol%; about 0.5 to 1 vol%; about 0.6 to 0.9 vol%; or about 0.7 to 0.8 vol%. the nanosheets 106h may be present in the nanofiller-polymer layer 106 at no greater than about 5 vol%; no greater than about 4 vol%; no greater than about 3 vol%; no greater than about 2 vol%; no greater than about 1 vol%; no greater than about 0.9 vol%; no greater than about 0.8 vol%; no greater than about 0.7 vol%; no greater than about 0.6 vol%; no greater than about 0.5 vol%; no greater than about 0.4 vol%; no greater than about 0.3 vol%; or no greater than about 0.2 vol%. In various instances, the nanosheets 106b may be present in the nanofiller-polymer layer 106 at no less than about 0.1 vol%; no less than about 0.2 vol%; no less than about 0.3 vol%; no less than about 0.4 vol%; no less than about 0.5 vol%; no less than about 0.6 vol%; no less than about 0.7 vol%; no less than about 0.8 vol%; no less than about 0.9 vol%; no less than about 1 vol%; no less than about 2 vol%; no less than about 3 vol%; or no less than about 4 vol%.III. Exemplary Dielectric Capacitors

[0053] FIG. 2 schematically depicts an exploded perspective view of an exemplary dielectric capacitor 200, as well as an externally applied electric field E for reference.A. Exemplary Dielectric Capacitor Components

[0054] As depicted in FIG. 2, exemplary dielectric capacitors 200 comprise a first electrode substrate 202, a second electrode substrate 204, and a thin polymer film 100. As shown, the first polymer layer 102 is positioned on the first electrode substrate 202, and the second electrode substrate 204 is positioned on the second polymer layer 104.

[0055] Nanofiller-polymer layer 106 comprises polymer 106< and nanosheets 106 >. As shown in FIG. 2, the planar surfaces of nanosheets 106b of nanofiller-polymer layer 106 are oriented orthogonal to an externally applied electric field E.

[0056] Various electrode substrates known in the art for dielectric capacitors may be used as the first electrode substrate 202. For example, the first electrode substrate 202 may be a metal coated wafer, a foil, or an evaporated metal. In various instances, the first electrode substrate 202 may comprise one or more metals, such as silver (Ag), iron (Fe), copper (Cu), nickel (Ni), chromium (Cr), gold (Au), platinum (Pt), aluminum (Al), and combinations thereof.

[0057] Various electrode substrates known in the art for dielectric capacitors may be used for the second electrode substrate 204. For example, the second electrode substrate 204 may be a metalcoated wafer, a foil, or an evaporated metal. In various instances, the second electrode substrate 204 may comprise one or more metals, such as silver (Ag), iron (Fe), copper (Cu), nickel (Ni), chromium (Cr), gold (Au), platinum (Pt), aluminum (Al), and combinations thereof.B. Exemplary Dielectric Capacitor Properties

[0058] In various instances, at room temperature, exemplary dielectric capacitors 200 may have a dielectric constant (F) of 19 to 22. In some instances, exemplary dielectric capacitors 200 may have a dielectric constant (F) of 19.2 to 21.8; 19.4 to 21.6; 19.6 to 21.4; 19.8 to 21.2; 20 to 21; 20.2 to 20.8; or 20.4 to 20.6. In various instances, at room temperature, exemplary dielectric capacitors 200 may have a dielectric constant (F) of no greater than 22; no greater than 21.8; no greater than 21.4; no greater than 21; no greater than 20.8; no greater than 20.4; no greater than 20; no greater than 19.8; or no greater than 19.4. In various instances, at room temperature, exemplary dielectric capacitors 200 may have a dielectric constant (F) of no less than 19; no less than 19.2; no less than 19.6; no less than 20; no less than 20.2; no less than 20.6; no less than 21; no less than 21.2; or no less than 21.6.

[0059] In various instances, exemplary dielectric capacitors 200 may have a dielectric strength (ABB) of greater than 1000 megavolts per meter (MV / m). In some instances, exemplary dielectric capacitors 200 may have a dielectric strength (EBD) of greater than 1025 MV / m; greater than 1050 MV / m; greater than 1075 MV / m; greater than 1100 MV / m; greater than 1125 MV / m; greater than 1150 MV / m; greater than 1175 MV / m; greater than 1200 MV / m; greater than 1225 MV / m; greater than 1250 MV / m; or greater than 1275 MV / m.

[0060] In various instances, exemplary dielectric capacitors 200 may have a capacitive discharge energy density (UD) of at least 50 J / cm3. In some instances, exemplary dielectric capacitors 200 may have a discharge energy density (UDof at least 55 J / cm3; at least 60 J / cm3; at least 65 J / cm3; at least 70 J / cm3; or at least 75 J / cm3.C. Exemplary Applications

[0061] Exemplary dielectric capacitors 200 may be incorporated into various energy storage devices, such as batteries and semiconductors. In various instances, exemplary dielectric capacitors 200 may be incorporated into various electrical devices. Exemplary dielectric capacitors200 may be used to store energy, filter out noise from signals, and / or supply a burst of power. In various instances, exemplary dielectric capacitors 200 may be incorporated into advanced weapons, defibrillators, and invertors.IV. Exemplary Methods of Preparing Exemplary Thin Film Polymers

[0062] Exemplary methods for preparing exemplary thin film polymers disclosed and contemplated herein may include one or more exemplary operations. FIG. 3 shows an exemplary method 300 for preparing exemplary thin film polymers contemplated and described herein. Optional operations are shown in dotted outline in FIG. 3.

[0063] As shown in FIG. 3, exemplary method 300 may include preparing a poly(m ethyl methacrylate) (PMMA) solution (operation 302); providing an array of nanosheets (operation 304); spin coating the poly(methyl methacrylate) solution onto the array of nanosheets to provide the nanofiller-polymer layer (operation 306); annealing the nanofiller-polymer layer (operation 308); preparing a polyfvinylidene fluoride) (PVDF) solution (operation 310); providing the first polymer layer positioned on a substrate (operation 312); depositing the nanofiller-polymer layer onto the first polymer layer (operation 314); drying the nanofiller-polymer layer deposited on the first polymer layer (operation 316); and spin coating the poly(vinylidene fluoride) solution onto the nanofiller-polymer layer to provide the second polymer layer (operation 318). Optionally, before providing the array of nanosheets (operation 304), the nanosheets may be mechanically exfoliated (operation 303). Other embodiments may include more or fewer operations.

[0064] In various instances, exemplary methods 300 may begin by preparing a poly(m ethyl methacrylate) (PMMA) solution (operation 302). The PMMA solution may comprise a first solvent and poly(m ethyl methacrylate). Preparing the PMMA solution (operation 302) may comprise adding poly(methyl methacrylate) (PMMA) to a first solvent.

[0065] Exemplary first solvents may include various organic solvents, such as dimethyl formamide (DMF), toluene, tetrahydrofuran (THF), N-Methyl-2-pyrrolidone (NMP), and combinations thereof.

[0066] Exemplary PMMA solutions may comprise PMMA at 0.1 wt% to 12 wt%. In various instances, exemplary PMMA solutions may comprise PMMA at 0.5 wt% to 10 wt%; 1 wt% to 9 wt%; 2 wt% to 8 wt%; 3 wt% to 7 wt%; or 6 wt% or 4 wt%. In various instances, exemplaryPMMA solutions may comprise PMMA at no greater than 12 wt%; no greater than 11 wt%; no greater than 10 wt%; no greater than 9 wt%; no greater than 8 wt%; no greater than 7 wt%; no greater than 6 wt%; no greater than 5 wt%; no greater than 4 wt%; no greater than 3 wt%; no greater than 2 wt%; no greater than 1 wt%; or no greater than 0.5 wt%. In various instances, exemplary PMMA solutions may comprise PMMA at no less than 0.1 wt%; no less than 0.5 wt%; no less than 1 wt%; no less than 2 wt%; no less than 3 wt%; no less than 4 wt%; no less than 5 wt%; no less than 6 wt%; no less than 7 wt%; no less than 8 wt%; no less than 9 wt%; no less than 10 wt%; or no less than 11 wt%.

[0067] In some instances, after adding the PMMA to the first solvent, the PMMA solution may be stirred. In various instances, exemplary PMMA solutions may be stirred for a period of 10 seconds to 24 hours. In various instances, exemplary PMMA solutions may be stirred for a period of 30 seconds to 22 hours; 1 minute to 20 hours; 2 minutes to 18 hours; 3 minutes to 16 hours; 4 minutes to 14 hours; 5 minutes to 12 hours; 10 minutes to 10 hours; 15 minutes to 8 hours; 20 minutes to 6 hours; 30 minutes to 5 hours; 40 minutes to 4 hours; 50 minutes to 3 hours; or 1 hour to 2 hours. In various instances, exemplary PMMA solutions may be stirred for a period of no greater than 24 hours; no greater than 22 hours; no greater than 20 hours; no greater than 18 hours; no greater than 16 hours; no greater than 14 hours; no greater than 12 hours; no greater than 10 hours; no greater than 8 hours; no greater than 6 hours; no greater than 4 hours; no greater than 2 hours; no greater than 1 hour; no greater than 30 minutes; no greater than 10 minutes; no greater than 5 minutes; or no greater than 1 minute. In various instances, exemplary PMMA solutions may be stirred for a period of no less than 10 seconds; no less than 30 seconds; no less than 1 minute; no less than 5 minutes; no less than 10 minutes; no less than 30 minutes; no less than 1 hour; no less than 2 hours; no less than 4 hours; no less than 6 hours; no less than 8 hours; no less than 10 hours; no less than 12 hours; no less than 14 hours; no less than 16 hours; no less than 18 hours; no less than 20 hours; or no less than 22 hours.

[0068] In various instances, exemplary PMMA solutions may be stirred at a temperature of 40 °C to 70 °C. In various instances, exemplary PMMA solutions may be stirred at a temperature of 45 °C to 65 °C; 47 °C to 63 °C; 50 °C to 60 °C; 52 °C to 58 °C; or 54 °C to 56 °C. In various instances, exemplary PMMA solutions may be stirred at a temperature of no greater than 70 °C; no greater than 65 °C; no greater than 60 °C; no greater than 55 °C; no greater than 50 °C; or nogreater than 45 °C. In various instances, exemplary PMMA solutions may be stirred at a temperature of no less than 40 °C; no less than 45 °C; no less than 50 °C; no less than 55 °C; no less than 60 °C; or no less than 65 °C.

[0069] After preparing the poly(methyl methacrylate) (PMMA) solution (operation 302), exemplary method 300 may comprise providing an array of nanosheets (operation 304), such as nanosheets 1066 described above. Exemplary nanosheets 106 > may comprise mica nanosheets and / or hexagonal boron-nitride nanosheets.

[0070] Optionally, before providing the array of nanosheets (operation 304), the nanosheets may be mechanically exfoliated (operation 303). Mechanical exfoliation of the nanosheets (operation 103) may include various exfoliation methods known in the art, such as scotch tape exfoliation. In various instances, the nanosheets may be mechanically exfoliated (operation 303) by applying a piece of scotch tape to crystals, such as mica- or hexagonal boron bitride (hBN)- based crystals, so that the crystals are adhered to the tape. Upon adhesion, the scotch tape may be peeled off the crystals to provide a tape comprising nanosheets. Then, the tape comprising the nanosheets may be positioned on a substrate surface and a force may be applied so that the tape comprising the nanosheets contacts the substrate surface. Then, the tape may be removed, thereby providing an array of exfoliated nanosheets positioned on the substrate surface.

[0071] Upon providing an array of nanosheets (operation 304), exemplary methods 300 may comprise spin coating the poly(methyl methacrylate) solution onto the array of nanosheets to provide a nanofdler-polymer layer (operation 306). Operation 306 thus generates a nanofdler- polymer layer, such as layer 106 described above. In various instances, spin coating the poly(m ethyl methacrylate) solution onto the array of nanosheets (operation 306) may occur at a rotational speed of 100 rpm to 10000 rpm. In various instances, spin coating the poly(methyl methacrylate) solution onto the array of nanosheets may occur at a rotational speed of 150 rpm to 9500 rpm; 200 rpm to 9000 rpm; 250 rpm to 8500 rpm; 300 rpm to 8000 rpm; 350 rpm to 7500 rpm; 400 rpm to 8000 rpm; 450 rpm to 7500 rpm; 500 rpm to 7000 rpm; 550 rpm to 6500 rpm; 600 rpm to 5000 rpm; 650 rpm to 4500 rpm; 700 rpm to 4000 rpm; 750 rpm to 3500 rpm; 800 rpm to 3000 rpm; 850 rpm to 2500 rpm; 900 rpm to 2000 rpm; or 950 rpm to 1500 rpm. In various instances, spin coating the poly(methyl methacrylate) solution onto the array of nanosheets (operation 306) may occur at a rotational speed of no greater than 10000 rpm; no greater than 9000rpm; no greater than 8000 rpm; no greater than 7000 rpm; no greater than 6000 rpm; no greater than 5000 rpm; no greater than 4000 rpm; no greater than 3000 rpm; no greater than 2000 rpm; no greater than 1000 rpm; no greater than 900 rpm; no greater than 800 rpm; no greater than 700 rpm; no greater than 600 rpm; no greater than 500 rpm; no greater than 400 rpm; no greater than 300 rpm; or no greater than 200 rpm. In various instances, spin coating the poly(methyl methacrylate) solution onto the array of nanosheets (operation 306) may occur at a rotational speed of no less than 100 rpm; no less than 200 rpm; no less than 300 rpm; no less than 400 rpm; no less than 500 rpm; no less than 600 rpm; no less than 700 rpm; no less than 800 rpm; no less than 900 rpm; no less than 1000 rpm; no less than 2000 rpm; no less than 3000 rpm; no less than 4000 rpm; no less than 5000 rpm; no less than 6000 rpm; no less than 7000 rpm; no less than 8000 rpm; or no less than 9000 rpm.

[0072] After spin coating the poly(methyl methacrylate) solution onto the array of nanosheets to provide the nanofiller-polymer layer (operation 306), exemplary methods may comprise annealing the nanofiller-polymer layer (operation 308).

[0073] In various instances, annealing the nanofiller-polymer layer (operation 308) may occur for a period of 1 to 10 minutes. In various instances, annealing the nanofiller-polymer layer (operation 308) may occur for a period of 1.5 to 9.5 minutes; 2 to 8 minutes; 2.5 to 7.5 minutes; 3 to 7 minutes; 3.5 to 6.5 minutes; 4 to 6 minutes; or 4.5 to 5.5 minutes. In various instances, annealing the nanofiller-polymer layer (operation 308) may occur for a period of no greater than 10 minutes; no greater than 9 minutes; no greater than 8 minutes; no greater than 7 minutes; no greater than 6 minutes; no greater than 5 minutes; no greater than 4 minutes; no greater than 3 minutes or no greater than 2 minutes. In various instances, annealing the nanofiller-polymer layer (operation 308) may occur for a period of no less than 1 minute; no less than 2 minutes; no less than 3 minutes; no less than 4 minutes; no less than 5 minutes; no less than 6 minutes; no less than 7 minutes; no less than 8 minutes; or no less than 9 minutes.

[0074] In various instances, annealing the nanofiller-polymer layer (operation 308) may occur at a temperature of 80 °C to 120 °C. In various instances, annealing the nanofiller-polymer layer (operation 308) may occur at a temperature of 85 °C to 115 °C; 87 °C to 113 °C; 90 °C to 110 °C; 92 °C to 107 °C; 95 °C to 105 °C; or 97 °C to 103 °C. In various instances, annealing the nanofiller- polymer layer (operation 308) may occur at a temperature of no greater than 120 °C; no greaterthan 115 °C; no greater than 110 °C; no greater than 105 °C; no greater than 100 °C; no greater than 95 °C; no greater than 90 °C; or no greater than 85 °C. In various instances, annealing the nanofiller-polymer layer (operation 308) may occur at a temperature of no less than 80 °C; no less than 85 °C; no less than 90 °C; no less than 95 °C; no less than 100 °C; no less than 105 °C; no less than 110 °C; or no less than 115 °C.

[0075] After annealing the nanofiller-polymer layer (operation 308), exemplary methods 300 may comprise preparing a poly(vinylidene fluoride) (PVDF) solution (operation 310). In various instances, preparing the PVDF solution (operation 310) may comprise adding poly(vinylidene fluoride) (PVDF) to a second solvent.

[0076] Exemplary second solvents may include various solvents, such as dimethyl formamide (DMF), toluene, tetrahydrofuran (THF), N-Methyl-2-pyrrolidone (NMP), and combinations thereof.

[0077] Exemplary PVDF solutions may comprise PVDF at 0.1 wt% to 20 wt%. In various instances, exemplary PVDF solutions may comprise PVDF at 0.2 wt% to 18 wt%; 0.5 wt% to 15 wt%; 1 wt% to 10 wt%; 2 wt% to 8 wt%; 3 wt% to 7 wt%; or 4 wt% to 6 wt%. In various instances, exemplary PVDF solutions may comprise PVDF at no greater than 20 wt%; no greater than 18 wt%; no greater than 15 wt%; no greater than 10 wt%; no greater than 8 wt%; no greater than 6 wt%; no greater than 5 wt%; no greater than 4 wt%; no greater than 3 wt%; no greater than 2 wt%; no greater than 1 wt%; no greater than 0.5 wt%; or no greater than 0.2 wt%. In various instances, exemplary PVDF solutions may comprise PVDF at no less than 0.1 wt%; no less than 0.2 wt%; no less than 0.5 wt%; no less than 1 wt%; no less than 2 wt%; no less than 3 wt%; no less than 4 wt%; no less than 5 wt%; no less than 6 wt%; no less than 7 wt%; no less than 8 wt%; no less than 9 wt%; no less than 10 wt%; no less than 15 wt%; or no less than 18 wt%.

[0078] In some instances, after adding the PVDF to the second solvent, the PVDF solution may be stirred. In various instances, exemplary PVDF solutions may be stirred for a period of 1 minute to 24 hours. In various instances, exemplary PVDF solutions may be stirred for a period of 2 minutes to 22 hours; 5 minutes to 20 hours; 7 minutes to 18 hours; 10 minutes to 15 hours; 12 minutes to 12 hours; 15 minutes to 10 hours; 20 minutes to 8 hours; 25 minutes to 5 hours; 30 minutes to 3 hours; or 1 hour to 2 hours. In various instances, exemplary PVDF solutions may be stirred for a period of no greater than 24 hours; no greater than 22 hours; no greater than 20 hours;no greater than 18 hours; no greater than 15 hours; no greater than 12 hours; no greater than 10 hours; no greater than 8 hours; no greater than 5 hours; no greater than 3 hours; no greater than 2 hours; no greater than 1 hours; no greater than 30 minutes; no greater than 20 minutes; no greater than 10 minutes; no greater than 5 minutes; or no greater than 2 minutes. In various instances, exemplary PVDF solutions may be stirred for a period of no less than 1 minute; no less than 2 minutes; no less than 5 minutes; no less than 7 minutes; no less than 10 minutes; no less than 12 minutes; no less than 15 minutes; no less than 20 minutes; no less than 25 minutes; no less than 30 minutes; no less than 1 hour; no less than 2 hours; no less than 3 hours; no less than 5 hours; no less than 8 hours; no less than 10 hours; no less than 12 hours; no less than 15 hours; no less than 18 hours; no less than 20 hours; or no less than 22 hours.

[0079] In various instances, exemplary PVDF solutions may be stirred at a temperature of 70 °C to 100 °C. In various instances, exemplary PVDF solutions may be stirred at a temperature of 75 °C to 95 °C; 76 °C to 94 °C; 77 °C to 93 °C; 78 °C to 92 °C; 79 °C to 91 °C; 80 °C to 90 °C; 81 °C to 89 °C; 82 °C to 88 °C; 83 °C to 87 °C; or 84 °C to 86 °C. In various instances, exemplary PVDF solutions may be stirred at a temperature of no greater than 100 °C; no greater than 95 °C; no greater than 90 °C; no greater than 85 °C; no greater than 80 °C; or no greater than 75 °C. IN various instances, exemplary PVDF solutions may be stirred at a temperature of no less than 70 °C; no less than 75 °C; no less than 80 °C; no less than 85 °C; no less than 90 °C; or no less than 95 °C.

[0080] After preparing the PVDF solution (operation 310), exemplary methods 300 may further comprise providing a first polymer layer positioned on a substrate (operation 312). In various instances, the first polymer layer may be positioned on the substrate by spray coating the PVDF solution onto the substrate. In various instances, the substrate may be an electrode substrate, such as first electrode substrate 202 discussed above.

[0081] After providing the first polymer layer positioned on a substrate (operation 312), exemplary methods may further comprise depositing the nanofiller-polymer layer onto the first polymer layer (operation 314). Depositing the nanofiller-polymer layer onto the first polymer layer (operation 314) may comprise positioning a nanofiller-polymer layer on the first polymer layer. In various instances, the nanofiller-polymer layer is positioned so that an entire surface of the nanofiller-polymer layer is contacting a surface of the first polymer layer. In various instances,after positioning the nanofiller-polymer layer on the first polymer layer, a force may be applied, thereby pressing the nanofiller-polymer layer and the first polymer layer together.

[0082] After depositing the nanofiller-polymer layer onto the first polymer layer (operation 314), exemplary methods 300 may comprise drying the nanofiller-polymer layer deposited on the first polymer layer (operation 316). In various instances, drying the nanofiller-polymer layer deposited on the first polymer layer (operation 316) may comprise blowing air and / or placing the nanofiller-polymer layer deposited on the first polymer layer in a hot air circulating chamber. In various instances, drying may occur under vacuum.

[0083] In various instances, drying the nanofiller-polymer layer deposited on the first polymer layer (operation 316) may occur for a period of 2 to 60 minutes. In various instances, drying the nanofiller-polymer layer deposited on the first polymer layer (operation 316) may occur for a period of 5 to 55 minutes; 10 to 50 minutes; 15 to 45 minutes; 20 to 40 minutes; or 25 to 35 minutes. In various instances, drying the nanofiller-polymer layer deposited on the first polymer layer (operation 316) may occur for a period of no greater than 60 minutes; no greater than 55 minutes; no greater than 50 minutes; no greater than 40 minutes; no greater than 30 minutes; no greater than 20 minutes; no greater than 10 minutes; or no greater than 5 minutes. In various instances, drying the nanofiller-polymer layer deposited on the first polymer layer (operation 316) may occur for a period of no less than 2 minutes; no less than 5 minutes; no less than 10 minutes; no less than 20 minutes; no less than 30 minutes; no less than 40 minutes; no less than 50 minutes; or no less than 55 minutes.

[0084] In various instances, drying the nanofiller-polymer layer deposited on the first polymer layer (operation 316) may occur at a temperature of 50 °C to 100 °C. In various instances, drying the nanofiller-polymer layer deposited on the first polymer layer (operation 316) may occur at a temperature of 55 °C to 95 °C; 60 °C to 90 °C; 65 °C to 85 °C; or 70 °C to 80 °C. In various instances, drying the nanofiller-polymer layer deposited on the first polymer layer (operation 316) may occur at a temperature of no greater than 100 °C; no greater than 95 °C; no greater than 90 °C; no greater than 85 °C; no greater than 80 °C; no greater than 75 °C; no greater than 70 °C; no greater than 65 °C; no greater than 60 °C; or no greater than 55 °C. In various instances, drying the nanofiller-polymer layer deposited on the first polymer layer (operation 316) may occur at a temperature of no less than 50 °C; no less than 55 °C; no less than 60 °C; no less than 65 °C; noless than 70 °C; no less than 75 °C; no less than 80 °C; no less than 85 °C; no less than 90 °C; or no less than 95 °C.

[0085] After drying the nanofiller-polymer layer deposited on the first polymer layer (operation 316), exemplary methods 300 may comprise spin coating the poly(vinylidene fluoride) solution onto the nanofiller-polymer layer to provide the second polymer layer (operation 318).

[0086] In various instances, spin coating the poly(vinylidene fluoride) solution onto the nanofiller-polymer layer (operation 318) may occur at a rotational speed of 100 rpm to 10000 rpm. In various instances, spin coating the poly(vinylidene fluoride) solution onto the array of nanosheets (operation 318) may occur at a rotational speed of 150 rpm to 9500 rpm; 200 rpm to 9000 rpm; 250 rpm to 8500 rpm; 300 rpm to 8000 rpm; 350 rpm to 7500 rpm; 400 rpm to 8000 rpm; 450 rpm to 7500 rpm; 500 rpm to 7000 rpm; 550 rpm to 6500 rpm; 600 rpm to 5000 rpm; 650 rpm to 4500 rpm; 700 rpm to 4000 rpm; 750 rpm to 3500 rpm; 800 rpm to 3000 rpm; 850 rpm to 2500 rpm; 900 rpm to 2000 rpm; or 950 rpm to 1500 rpm. In various instances, spin coating the poly(vinylidene fluoride) solution onto the array of nanosheets (operation 318) may occur at a rotational speed of no greater than 10000 rpm; no greater than 9000 rpm; no greater than 8000 rpm; no greater than 7000 rpm; no greater than 6000 rpm; no greater than 5000 rpm; no greater than 4000 rpm; no greater than 3000 rpm; no greater than 2000 rpm; no greater than 1000 rpm; no greater than 900 rpm; no greater than 800 rpm; no greater than 700 rpm; no greater than 600 rpm; no greater than 500 rpm; no greater than 400 rpm; no greater than 300 rpm; or no greater than 200 rpm. In various instances, spin coating the poly(vinylidene fluoride) solution onto the array of nanosheets (operation 318) may occur at a rotational speed of no less than 100 rpm; no less than 200 rpm; no less than 300 rpm; no less than 400 rpm; no less than 500 rpm; no less than 600 rpm; no less than 700 rpm; no less than 800 rpm; no less than 900 rpm; no less than 1000 rpm; no less than 2000 rpm; no less than 3000 rpm; no less than 4000 rpm; no less than 5000 rpm; no less than 6000 rpm; no less than 7000 rpm; no less than 8000 rpm; or no less than 9000 rpm.V. Experimental Examples

[0087] Without limiting the scope of the instant disclosure, experimental examples of embodiments discussed above were prepared and the results are discussed below.A. Materials and Methods

[0088] Heterostructure device fabrication. Poly (vinylidene fluoride) (PVDF) (MW: 534,000 by GPC), dimethyl formamide (DMF), and potassium hydroxide (KOH) were purchased from Sigma-Aldrich. PMMA was purchased from Microchem (currently named Kayaku Advanced Materials, Inc). Bulk 2D Mica sheets are purchased from SPI-Supplies. PVDF was dissolved in DMF, typically at 10 wt %. followed by stirring at 70 °C temperature for 3 hours. This PVDF solution was used to make the thin film of PVDF using spin coating. The thin film of PVDF was prepared on ITO (Indium Tin Oxide) coated glass substrate. Each layer of PVDF thin film is prepared by spin coating of 10 wt % of PVDF solution in DMF solvent at 1700 rpm for 60 secs followed by annealing at 100 °C for 5 minutes. To make PVDF film smoother and uniform, two layers (two times coating) of PVDF were coated on the ITO substrate.

[0089] Dielectric permittivity, breakdown strength, and polarization measurements. Temperature-dependent dielectric measurements were carried out using an LCR meter, Model: IM-3536 LCR Meter at the ambient condition with a temperature-controlled hot plate as a function of frequency range from 100 Hz to 8 MHz from room temperature (RT) to 180 °C at ambient condition. All the samples were annealed initially at 180 °C for 45 minutes before measuring frequency and temperature-dependent dielectric properties. Data were collected at each 10 °C difference in the temperature range. Dielectric constant (s) was extracted using the relation C = permittivity in free space, e is the dielectric constantof the sample, A is the area of the capacitor, and d is the separation distance between two plates or thickness of dielectric materials (heterostructure capacitor). The capacitor area for dielectric measurements is typically (-350 X 350 pm2) area, fabricated using conducting Ag paint or thermally deposited Au electrodes on the top PVDF layer (top electrode). The sample thickness measured from contact mode AFM for the samples presented in FIGS. 4A-4C (for Mica) was500+ / — 50 nm. The average thickness was used to extract the dielectric constants. The thickness of A-BN interfaced heterostructure capacitors was measured between 600+ / -50 nm.

[0090] Breakdown voltage measurements were conducted using the PolyK testing system PK CPE- 1801 equipped with a High voltage TREK amplifier Model # 609D-6. A ramp rate of 20 V / s was selected for the testing and the breakdown values were recorded using the PolyK software. The data were analyzed using a two-parameter Weibull fit aswhere E is the breakdown field, EBD is the dielectric breakdown strength, i.e., breakdown strength at 63.2% probability of failure, is the shape parameter and P(E) is the probability of failure.

[0091] The electric displacement vs electric field (D-E loop) measurements were performed using the PolyK PK CPE-1801 system. The top electrodes for the D-E loop measurement were fabricated using Gallium-Indium liquid metal and had diameters of around -200-300 microns. The liquid metal electrodes were connected to the instruments using needlepoint contacts. Raman measurements on bulk Mica was done using a 785 nm laser source (MacroRAM™ benchtop Raman spectrometer) in the range of 100 to 1000 cm1at ambient condition. Fourier Transform Infrared Spectroscopy (FTIR) measurement was conducted using Perkin-Elmer- Spectrum two FT-IR spectrometers in the range 4000-450Atomic force microscope (AFM) images of the surface morphology and height measurements were conducted using Veeco Dimension 3100 AFM instrument in contact mode.

[0092] Fabrication of Heterostructure Capacitor. FIG. 5 illustrates the method for preparing the heterostructure devices in the following experimental examples. As as shown in FIG. 5, the schematic design of the heterostructure device consists of layers of PVDF and Mica (supported by the PMMA layer). To prepare the devices, mechanically exfoliated 2D Mica flakes (squares) were transferred onto a clean SiC>2 / Si substrate. On purpose, a section of the SiO2 / Si wafer was kept clean without transferring any 2D flakes. The whole wafer was covered with PMMA polymer using the spin coating technique and baked at 100 °C for 2 minutes. The whole wafer (PMMA / 2D- Mica / SiO2 / Si) was then dipped inside the KOH solution to etch the SiO2 layer and release the PMMA holding the 2D Mica layers to the solvent. PMMA holding 2D-layered Mica crystals was later fished using a clean glass slide and transferred into the H2O to remove any excess KOH solvent from the PMMA / 2D-Mica layers. The 2D-Mica / PMMA layer was then transferred ontothe spin-coated PVDF film (bottom PVDF) on the ITO glass slides and the resulting device contained layers of ITO / PVDF / Mica-PMMA. Finally, the top polymer layer (PVDF) was coated to complete the PVDF / 2D Mica-PMMA / PVDF heterostructure device. Finally, FIG. 5 illustrates the final device used for dielectric measurements. The reference as well as mica-interfaced areas of the sample is labeled on the edge of the schematic. The Mica nanosheets were exfoliated using scotch tape through mechanical exfoliation technique and then transferred onto 285 nm SiO2 deposited on Si substrate in such a way that half of the SiO wafer remain empty, and half of the wafer is covered with transferred Mica flakes (FIG. 5). The empty half of the substrate was used as a reference capacitor and Mica covered half area used as the 2D filler interfaced capacitor. A Raman spectroscopy study was used on a thick layer of Mica crystal to verify the Mica crystal. After the transfer process, the 2D Mica flakes were observed under the optical microscope to verify the quality of distribution of the exfoliated crystals on the Si / SiC>2 substrate. The thickness of the 2D Mica flakes varied from a single layer to several atomic layers but the average thickness of the flakes obtained from AFM measurements was 20 nm.

[0093] The optical images shown in FIGS. 4A-4C indicate the size and distribution of the flakes are random and nonuniform and the density of flakes varies across the exfoliated area of the substrate. A thin layer of PMMA was coated on the top of the exfoliated Mica sheets by spin coating a PMMA solution at 1600 rpm followed by annealing at 110 °C for 2 minutes, providing sufficient adhesion of the flakes to PMMA. Finally, this PMMA layer with 2D-Mica nanosheets was etched from the Si / SiOs substrate using SiCh etchant, and KOH solvent and transferred onto the PVDF coated layer on ITO substrate to obtain an ITO / PVDF / 2D Mica-PMMA heterostructure (FIG. 5, bottom). After subsequent drying in vacuum, a top thin layer of PVDF was coated on the ITO / PVDF / 2D Mica-PMMA heterostructure to obtain the final PVDF / 2D Mica-PMMA / PVDF heterostructure on the ITO as shown in the bottom of FIG. 5. Half of the substrate yields a reference capacitor, PVDF / PMMA / PVDF, and the other half yields PVDF / 2D Mica-PMMA / PVDF heterostructure capacitor shown in FIG. 5. In the fabricated capacitor devices, the thickness of the PVDF / PMMA-2D Mica / PVDF heterostructure was measured, and the average thickness was -500 nm ± 50 nm. The non-uniformity arises from the manual transfer process of 2D Mica / PMMA layers. The thickness of the polymer layers was kept as low as possible to observe the maximum effect of 2D fillers on dielectric properties from the heterostructure assembly of the device as wellas to limit the leakage or dielectric loss. In this vertically stacked geometry, the 2D surfaces of Mica flakes are parallel to the electrodes or perpendicular to the externally applied electric field E as illustrated in FIG. 2. It was observed that the 2D Mica nanofillers are intact in the final heterostructures using scanning electron microscopy (SEM).B. Results

[0094] Permittivity Enhancement in Polymer-2D Layered Mica Heterostructures . FIGS. 6A- 6B display the dielectric constant of reference (PVDF / PMMA / PVDF) and stratified Mica interfaced capacitors (PVDF / PMMA-2D Mica / PVDF) respectively as a function of temperature and frequency. The reference capacitor shows a dielectric constant (e) = 11-13.5 at room temperature, similar as compared to pristine PVDF. The 2D mica nanofiller-based heterostructures capacitor shows = 19-22 at room temperature as a function of frequency. The permittivity of 2D Mica-based heterostructures is 60-75% higher than the reference heterostructure samples as shown in FIG. 6C. The enhancement, Ae of oriented 2D Mica-based heterostructures is much higher than the expected volumetric contribution of permittivity by the Mica nanofillers given that the filler volume fraction is very small (~ 1 vol%) and Mica permittivity ranges from 6-9. It is hypothesized that the highly enhanced permittivity of 2D Mica-based samples stems from the additional interfacial dipoles along the 2D plane due to the perpendicular (to the electric field) orientation of nanofillers. The large surface area of the 2D fillers provides ultra-large interfacial area per unit volume with the polymers where each small 2D flake acts as a micro-capacitor, as shown in FIG. 6F. The enhancement values of permittivity, AE varies with the density of the filler content and low enhancement was also observed in some areas of the capacitor, presumably from low 2D filler contain capacitor. Interestingly, the loss tangent of the 2D nanofiller-based capacitor is comparable to the control reference capacitor at low frequency as shown in FIGS. 6D-6E. Typically, such enhancements in permittivity of polymers are obtained by high loadings of randomly dispersed inorganic nanofillers (> 10 vol%), which results in high losses as well.

[0095] Dielectric Strength and Capacitive Energy Density Measurements for Heterostructures. The 2D inorganic nanofillers have been shown to enhance the dielectric strength of polymeric nanocomposites depending on the concentration of fillers. Typically, high fractions10 wt. %) of randomly distributed 2D nanofillers are used to increase the dielectric strength (~60-70 % enhancements) of polymeric nanocomposites. Here, although the fraction of mica (or h- BN) nanofillers is very low (~ 1 vol %), the nanofillers were expected to increase the dielectric strength as the orientation of the 2D surface of the nanofillers are completely perpendicular to the applied electric field and can resist electrical treeing as shown in FIGS. 7A-7B. Furthermore, the above theoretical studies confirmed that the in-plane alignment of the polymer chain axis leads to in-plane dipoles which helps enhance the dielectric strength or reduce the electrical treeing process. FIG. 8 shows two-parameter Weibull probability plots and fits of reference vs stratified 2D Mica containing heterostructures capacitors measured at room temperature. The oriented Micabased heterostructures capacitor shows an ultra-high dielectric strength of ~ 1270 MV / m, which is = 117% higher than the reference heterostructure capacitor using the thickness of the capacitor is 600 nm. This enhancement in dielectric strength is significant given that the nanofiller fraction is only = 1 vol%. Simulation results predicted the 40% enhancement of the breakdown voltage in h- BN filler PVDF-CTFE and PVDF-TrFE-CFE composites at 8-10 vol% of filler concentration. Along with increased dielectric strength, the values also increase, showing that the reliability of dielectrics also increases. FIGS. 9A-9B show the electrical displacement vs electric field and discharge energy density (J / cm3) and efficiency for the stratified Mica-based heterostructures and the reference capacitors respectively. The stratified 2D Mica based polymer heterostructures show an ultra-high discharge energy density of = 75 J / cm3with an efficiency of over 79% at a maximum electric field of 1247 MV / m, while the pure polymer heterostructures show a discharge energy density of 4.54 J / cm3with an efficiency of 78.9 % at an electric field of 483 MV / m. The energy density of the 2D Mica nanofiller-based capacitor is an order of magnitude higher than the pure polymer samples and stems from the increase in both permittivity and dielectric strength. The electrical treeing effect is significantly reduced in 2D-Mica interfaced capacitors due to the perpendicular alignment of the dipoles with respect to the field direction at the interface between polymer and fillers. Furthermore, the energy density of the PVDF / PMMA-2D Mica / PVDF samples is the highest to date for any thin film polymer composites as shown in FIGS. 10A-10B.

[0096] Versatility of Capacitive Energy Density Enhancement using Oriented 2D Nanofillers. To test the versatility of ultra-high energy storage properties of stratified 2D nanofiller-based polymeric dielectrics, another two-dimensional dielectric material hexagonal Boron Nitride ( / z-BN) nanofillers was investigated as a replacement for 2D Mica nanofillers. FIG.11 shows the enhancement of the dielectric constant of PVDF / PMMA-Zz-BN / PVDF heterostructures as compared to PVDF / PMMA / PVDF heterostructures. The A-BN based heterostructures show an increase of 40-45% in the permittivity at room temperature. The enhancement of the dielectric constant in PVDF / PMMA-A-BN / PVDF capacitor was observed to be lower than that observed for PVDF / PMMA-2D Mica / PVDF heterostructures. Dielectric permittivity £ oc, N is the density of the atom in the material, and Egis the energy gap. Mica has a higher density (~3g / cm3) compared to the A-BN (~2 g / cm3). Mica nanosheets have a lower band gap (~3-4 eV for 1 -5 layers) compared to A-BN (~6 eV) making the dielectric constant of the Mica interfaced capacitor presumably higher than the A-BN interfaced capacitor. FIG. 12 shows the Weibull probability plots of PVDF / PMMA / PVDF and PVDF / PMMA- / ?-BN / PVDF heterostructures. The dielectric strength of PVDF / PMMA-A-BN / PMMA heterostructures is « 170% higher than that of the control heterostructures and is higher than that observed for their Mica counterparts. The higher dielectric strength of A-BN based heterostructures might be due to their high resistance to breakdown, which is dependent on the 2D flake thickness. FIGS. 13A-13B show the electric displacement vs electric field and discharge energy density and efficiency plots of PVDF / PMMA- / 1-BN / PVDF and PVDF / PMMA / PVDF heterostructures. The / z-BN based heterostructures can store an ultra-high energy density of ~ 50 J / cm3with an efficiency of over 52% despite very low filler fraction (« 1 vol%), which is the highest among any literature reported polymeric dielectrics. The lower value of energy density in A-BN based heterostructures is due to their slightly lower permittivities (polarizability and higher bandgap) as compared to the Mica heterostructures. This demonstrates that the approach of using stratified 2D nanofillers within the polymer matrix is versatile for designing ultra-high energy density polymeric dielectric capacitors.

[0097] Certain embodiments encompassed by this disclosure are particularly enumerated below.Enumerated embodiment 1 (Ee 1). A thin polymer film, comprising: a first polymer layer comprising poly(vinylidene fluoride); a second polymer layer comprising poly(vinylidene fluoride); and a nanofiller-polymer layer interposed between the first polymer layer and the second polymer layer,the nanofiller-polymer layer comprising poly(methyl methacrylate) and nanosheets dispersed in the poly(methyl methacrylate); the nanosheets comprising mica nanosheets and / or hexagonal boron-nitride nanosheets; wherein 50-99% of the nanosheets in the nanofiller-polymer layer are oriented parallel to a width dimension of the first polymer layer.Ee 2. The thin polymer film of Ee 1, wherein the thin polymer film has a thickness of 300 nm to 15 pm.Ee 3. The thin polymer film of Ee 1 or 2, wherein the first polymer layer has a thickness of 100 nm to 5 pm; and wherein the second polymer layer has a thickness of 100 nm to 5 pm.Ee 4. The thin polymer film of any one of Ees 1 to 2, wherein the nanofiller-polymer layer has a thickness of 100 nm to 5 pm.Ee 5. The thin polymer film of any one of Ees 1 to 4, wherein the nanosheets have an average thickness of 1 nm to 50 nm.Ee 6. The thin polymer film of any one of Ees 1 to 5, wherein the nanofiller-polymer layer has an area of 0.01 pm2to 1000 pm2.Ee 7. The thin polymer film of Ee 6, wherein the nanosheets cover at least 50% of the area of the nanofiller-polymer layer.Ee 8. The thin polymer film of any one of Ees 1 to 7, wherein the nanosheets are present in the nanofiller-polymer layer at about 0.1% to 5% by volume.Ee 9. A dielectric capacitor, comprising:a first electrode substrate; a second electrode substrate; and the thin polymer film of Ee 1, wherein the first polymer layer is positioned on the first electrode substrate, and the second electrode substrate is positioned on the second polymer layer.Ee 10. The dielectric capacitor of Ee 9, wherein the dielectric capacitor has a dielectric constant (f) of 19 to 22 at room temperature.Ee 11. The dielectric capacitor of Ee 9 or 10, wherein the dielectric capacitor has a dielectric strength (EBD) of greater than 1000 megavolts per meter (MV / m).Ee 12. The dielectric capacitor of any one of Ees 9 to 11, wherein the dielectric capacitor has a capacitive discharge energy density (UD) of at least 50 J / cm3.Ee 13. An energy storage device comprising the dielectric capacitor of any one of Ees 9 to 12.Ee 14. A method of manufacturing the thin polymer film of any one of Ees 1 to 8, the method comprising: preparing a poly(methyl methacrylate) solution comprising a first solvent and poly(methyl methacrylate); providing an array of nanosheets comprising mica nanosheets and / or hexagonal boronnitride nanosheets; spin coating the poly(methyl methacrylate) solution onto the array of nanosheets to provide the nanofiller-polymer layer; annealing the nanofiller-polymer layer; preparing a poly(vinylidene fluoride) solution comprising a second solvent and poly (vinylidene fluoride); providing the first polymer layer positioned on a substrate; depositing the nanofiller-polymer layer onto the first polymer layer;drying the nanofiller-polymer layer deposited on the first polymer layer; and spin coating the poly(vinylidene fluoride) solution onto the nanofiller-polymer layer to provide the second polymer layer.Ee 15. The method of Ee 14, wherein before providing the array of nanosheets, the nanosheets are mechanically exfoliated.

Claims

CLAIMS1. A thin polymer film, comprising: a first polymer layer comprising poly(vinylidene fluoride); a second polymer layer comprising poly(vinylidene fluoride); and a nanofiller-polymer layer interposed between the first polymer layer and the second polymer layer, the nanofiller-polymer layer comprising poly(methyl methacrylate) and nanosheets dispersed in the poly(methyl methacrylate); the nanosheets comprising mica nanosheets and / or hexagonal boron-nitride nanosheets; wherein 50-99% of the nanosheets in the nanofiller-polymer layer are oriented parallel to a width dimension of the first polymer layer.

2. The thin polymer film of claim 1, wherein the thin polymer film has a thickness of 300 nm to 15 pm.

3. The thin polymer film of claim 1, wherein the first polymer layer has a thickness of 100 nm to 5 pm; and wherein the second polymer layer has a thickness of 100 nm to 5 pm.

4. The thin polymer film of claim 1, wherein the nanofiller-polymer layer has a thickness of 100 nm to 5 pm.

5. The thin polymer film of claim 1, wherein the nanosheets have an average thickness of 1 nm to 50 nm.

6. The thin polymer film of claim 1, wherein the nanofiller-polymer layer has an area of 0.01 pm2to 1000 pm2.

7. The thin polymer film of claim 6, wherein the nanosheets cover at least 50% of the area of the nanofiller-polymer layer.

8. The thin polymer film of claim 1, wherein the nanosheets are present in the nanofiller- polymer layer at about 0.1% to 5% by volume.

9. A dielectric capacitor, comprising: a first electrode substrate; a second electrode substrate; and the thin polymer film of claim 1, wherein the first polymer layer is positioned on the first electrode substrate, and the second electrode substrate is positioned on the second polymer layer.

10. The dielectric capacitor of claim 9, wherein the dielectric capacitor has a dielectric constant (7 ) of 19 to 22 at room temperature.

11. The dielectric capacitor of claim 9, wherein the dielectric capacitor has a dielectric strength (EBD) of greater than 1000 megavolts per meter (MV / m).

12. The dielectric capacitor of claim 9, wherein the dielectric capacitor has a capacitive discharge energy density (UD) of at least 50 J / cm3.

13. An energy storage device comprising the dielectric capacitor of claim 9.

14. A method of manufacturing the thin polymer film of claim 1, the method comprising: preparing a poly (methyl methacrylate) solution comprising a first solvent and poly(m ethyl methacrylate); providing an array of nanosheets comprising mica nanosheets and / or hexagonal boronnitride nanosheets;spin coating the poly(methyl methacrylate) solution onto the array of nanosheets to provide the nanofiller-polymer layer; annealing the nanofiller-polymer layer; preparing a poly (vinylidene fluoride) solution comprising a second solvent and poly(vinylidene fluoride); providing the first polymer layer positioned on a substrate; depositing the nanofiller-polymer layer onto the first polymer layer; drying the nanofiller-polymer layer deposited on the first polymer layer; and spin coating the poly(vinylidene fluoride) solution onto the nanofiller-polymer layer to provide the second polymer layer.

15. The method of claim 14, wherein before providing the array of nanosheets, the nanosheets are mechanically exfoliated.

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