Capacitance Density Research Articles

Pt-doped TiO2 nanotubes as photocatalysts and electrocatalysts for enhanced photocatalytic H2 generation, electrochemical sensing, and supercapacitor applications

Hydrogen production plays a major role in both the stationary and transportation energy sectors. Electrochemical sensing is an additional sensitive electrochemical application for the detection of trace analytes. Semiconductor-based catalysts can be used for both of these applications. While doping these semiconductors, it improves the pure semiconductor's electrical properties. TiO2 nanotubes (NTbs) and Pt-doped TiO2 NTbs were successfully synthesized by the hydrothermal method at various doping concentrations. They were subjected to different methodical characterization tools such as XRD, FT-IR, UV-DRS, SEM, and TEM. Out of various doping concentrations of Pt, 1.6% Pt-doped TiO2 NTbs shows superior H2 generation through photocatalytic water splitting reactions, which is attributed to the high electrical conductivity and stable electrical properties of it with a low impedance of 79 Ohms. The amount of hydrogen gas produced from 1.6% Pt-doped TiO2 was found to be 19.22 mmolh−1g−1, which is due to the reduced band gap of the material from the incorporation of Pt into pure TiO2. Prepared NTbs were examined for their electrochemical activity towards the detection of nitrite at very low concentrations. The enhanced electrochemical activity of 1.6% Pt-doped TiO2 NTbs is effective in detecting nitrite with a detection limit of 14.7 nM. A supercapacitor device has been constructed using 1.6% Pt-doped TiO2. The constructed device produced stable cyclic voltammograms up to the maximum scan rate of 10,000 mVs−1 with a potential window of 2 V. The maximum specific capacitance and Energy density (Ed) of a 1.6% Pt-doped TiO2-based supercapacitor were determined to be 750.01 F/g and 78.8 Wh/Kg, respectively. These results demonstrate that it is an excellent material for energy storage applications.

Constructing a Hierarchical Ternary Hybrid of PEDOT:PSS/rGO/MoS2 as an Efficient Electrode for a Flexible Fiber-Shaped Supercapacitor

Improving the specific capacitance and energy density of a fiber-shaped supercapacitor (FSSC) is critical to its applications as an energy storage device for advanced smart wearable electronics. In this paper, a heterogeneous poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/reduced graphene oxide/molybdenum disulfide (PEDOT:PSS/rGO/MoS2) fiber was prepared to achieve a high-performance and durable electrode for the FSSC. As indicated, pseudocapacitive MoS2 was in situ grown on a highly conductive acid-treated PEDOT:PSS/rGO assembly with a hierarchical structure. This structural design emphasizes the wrinkled morphology and high conductivity of the PEDOT:PSS/rGO backbone to maximize the MoS2 deposition and accelerate its electron transfer, which fully utilizes the pseudocapacitance of MoS2 and provides additional capacitance contribution to the obtained device. Attributed to the synergy, the prepared fiber electrode in the FSSC exhibits high volumetric/areal specific capacitance (325.8 F cm–3/405.3 mF cm–2 at 1 A cm–3 or 1.2 mA cm–2) and excellent rate performance (82%, 1–10 A cm–3). The corresponding device shows an ultrahigh volumetric energy density of 6.9 mW h cm–3 at a high power density of 173.6 mW cm–3 and an areal energy density of 8.5 μW h cm–2 at 215.9 μW cm–2, together with excellent cycle stability and mechanical flexibility, outperforming most of the previously reported FSSCs. Accordingly, the proposed strategy provides a great opportunity to develop a high-performance FSSC for further wearable electronics.

Utilizing hybrid faradaic mechanism via catalytic and surface interactions for high-performance flexible energy storage system

Improving the capacitance and energy density is a significant challenge while developing practical and flexible energy storage system (ESS). Redox mediators (RMs), as redox-active electrolyte additives, can provide additional energy storing capability via electrochemical faradaic contribution on electrodes for high-performance flexible ESSs. Particularly, determining effective material combinations between electrodes and RMs is essential for maximizing surface faradaic redox reactions for energy-storage performance. In this study, an electrode-RM system comprising heterostructured hybrid (carbon fiber (CF)/MnO2) faradaic electrodes and iodine RMs (I-RMs) in a redox-active electrolyte is investigated. The CF/MnO2 with the I-RMs (CF/MnO2-I) induces dominant catalytic faradaic interaction with the I-RMs, significantly enhancing the surface faradaic kinetics and increasing the overall energy-storage performance. The CF/MnO2-I ESSs show a 12.6-fold (or higher) increased volumetric energy density of 793.81 mWh L−1 at a current of 10 µA relative to ESSs using CF/MnO2 without I-RMs (CF/MnO2). Moreover, the CF/MnO2-I retains 93.1% of its initial capacitance after 10,000 cycles, validating the excellent cyclability. Finally, the flexibility of the ESSs is tested at different bending angles (180° to 0°), demonstrating its feasibility for flexible and high-wear environments. Therefore, CF/MnO2 electrodes present a practical material combination for high-performance flexible energy-storage devices owing to the catalytic faradaic interaction with I-RMs.

Preparation of rGO/PEDOT:PSS composite with high photothermal conversion efficiency for light enhanced quasi-solid-state supercapacitor

The suppression of performance degradation at low temperatures and the improvement of capacity are still important issues that need to be solved for many energy storage devices. Here, we prepared reduced graphene oxide/poly(3,4-ethylenedioxythiophene):poly(sodium styrene sulfonate) composite (rGO/PEDOT:PSS) via a facile hydrothermal reaction, and apply it to a symmetric supercapacitor. On the one hand, the optimized composite exhibits improved electrochemical performance, and its specific capacitance is 50 % higher than that of pure rGO; on the other hand, the optimized composite also exhibits excellent photothermal properties, under the NIR light illumination intensity of 1.05 W cm−2 (808 nm), it shows a high photothermal conversion efficiency of 62.0 %. Thus, the photothermal effect enhances the performance of the supercapacitor, and under a low illumination intensity of 0.18 W cm−2, its specific capacitance and energy density could be increased to 1.8 and 1.6 times higher than those in the dark condition, respectively. This study provides new design ideas for the development of next-generation flexible and wearable devices and more smart options for the wide application of light energy.

Direct writing additive-free V2CTx MXene architectures enables Zn-ion hybrid capacitor with ultrahigh energy density

Constructing a Zinc ion hybrid supercapacitor (ZHMSC) configuration with excellent electrochemical performance for progressive energy storage is worldwide attractive but yet still a considerable challenge. In this study, a universal and effective strategy has been proposed and developed for 3D-writing additive-free V2CTx MXene architected ZHMSC to realize the excellent electrochemical performance. With proper designs of printable electrochemical materials and direct ink writing architectures, 3D printed ZHMSC devices with high areal capacitance and excellent areal energy density have been achieved in a limited footprint area. Benefitting from the excellent ion diffusion and highly conductive networks, the 3D printed ZHMSCs device achieves the ultrahigh specific capacitance of 3.82 F cm−2, large energy density of 1.36 mW h cm−2 and remarkable cyclic performance with the capacitance retention of 97.8 % after 12,000 cycles at 20 mA cm−2. This work not only provides new insights on direct ink writing for high-performance Zn-Ion hybrid capacitor, but also offers a facile and efficient method to construct large-scale energy storage devices with high electrochemical performance for future energy storage.

ESR Modeling of Class II MLCC Large-Signal-Excitation Losses

Multilayer Ceramic Capacitors (MLCCs) with ferroelectric Class II dielectrics enable extremely high volumetric capacitance density, and are therefore preferred in high-power-density power conversion. These MLCCs, though, suffer from a non-linear dielectric constant and substantial low-frequency, large-signal excitation losses. Previously, a Steinmetz-parameter-based loss model accurately described these large-signal losses in MLCCs, but a difficult peak-charge measurement was required. For magnetic materials, a Steinmetz-based model is translated to an operating-point-specific Effective Series Resistance (ESR) model, which then allows for a low-complexity loss calculation. In this Letter, we introduce and verify an Effective Series Resistance (ESR)-based loss model for MLCCs, with the ESR derived from the MLCC Steinmetz parameters. Our modelling error is below 25 % across all evaluated operating points, a major improvement over modelling with the small-signal ESR provided in the MLCC datasheet, which may result in a loss approximation error of up to 10×.

Silver-doped reduced graphene oxide/Pani composite synthesis and their supercapacitor applications

In this study, graphene oxide was synthesized by the Hummers method. Reduced graphene oxide was obtained by the hydrothermal method. Then, silver-doped Reduced Graphene Oxide/Polyaniline (Ag-doped rGO/PANI) composites were synthesized. Some physical analyzes of the synthesized composite materials were made. In the XRD examination, it was understood that the materials generally have polyaniline properties. Electrochemical properties were investigated with electrodes prepared from these composites. Specific capacitance, energy, and power density values were calculated from these measurements. The specific capacitance was measured in the range of 0.5–30 A/g and the highest capacitance value was found to be 379 F/g. From these results, the material containing approximately 17 mass percent silver doped reduced graphene oxide gave better results among composite materials. This composite was the most stable material with results of 286–317 F/g at all applied currents. In addition, a coin cell application was made for this example and its measurements were taken.

2D‐Nanofiller‐Based Polymer Nanocomposites for Capacitive Energy Storage Applications

High‐energy‐density storage devices play a major role in modern electronics from traditional lithium‐ion batteries to supercapacitors for a variety of applications from rechargeable devices to advanced military equipment. Despite the mass adoption of polymer capacitors, their application is limited by their low energy densities and low‐temperature tolerance. Polymer nanocomposites based on 2D nanomaterials have superior capacitive energy densities, higher thermal stabilities, and higher mechanical strength as compared to the pristine polymers and nanocomposites based on 0D or 1D nanomaterials, thus making them ideal for high‐energy‐density dielectric energy storage applications. Here, the recent advances in 2D‐nanomaterial‐based nanocomposites and their implications for energy storage applications are reviewed. Nanocomposites based on conducting 2D nanofillers such as graphene, reduced graphene oxide, MXenes, semiconducting 2D nanofillers including transition metal dichalcogenides such as MoS2, dielectric 2D nanofillers including hBN, Mica, Al2O3, TiO2, Ca2Nb3O10 and MMT, and their effects on permittivity, dielectric strength, capacitive energy density, efficiency, thermal stability, and the mechanical strength, are discussed. Also, the theory and machine‐learning‐guided design of polymer 2D nanomaterial composites is learnt and the challenges and opportunities for developing ultrahigh‐capacitive‐energy‐density devices based on these nanofiller polymer composites are presented.

Modeling of capacitance for carbon-based supercapacitors using Super Learner algorithm

Due to some specifications such as high capacitance and power density, electrostatic double-layer capacitors (EDLCs) are more noticeable than other supercapacitors. Some physical and chemical properties, surface functional groups, and testing conditions affect the efficiency and in particular the capacitance of EDLCs with carbon-based electrodes. In this study, four machine learning models, including Super Learner (SL), Extremely Randomized Trees (Extra trees), Extreme learning machine (ELM), and Multivariate adaptive regression splines (MARS) were implemented to predict the EDLCs' capacitance based on different impressive properties. A large dataset was assigned to the 121 different carbonaceous electrodes collected under various conditions, including 13 physical and chemical properties: voltage window (V), specific surface area (SSA) and SSA of micropore, pore volume (PV), and micropore volume, the ratio of D-band and G-band (Id/Ig) and doping elements (inputs parameters). The results indicated that the SL model with the R2 values of 0.9781, 0.9717, and 0.9768 for training, testing, and total dataset, respectively, and the RSME value of 18.099 was the most accurate model in comparison with the others. Indeed, the sensitivity analysis results exhibited that SSA with the relevance factor of 0.323 is the most important feature in the capacitance of carbon-based electrodes, while the presence of boron, sulfur, fluorine, phosphorus doping elements and pore size can be ignored.

Disulfonated polyarylene ether sulfone membrane for graphitic carbon nitride/zinc oxide based photo-supercapacitors

Photo-supercapacitors (PSCs) are environmentally friendly devices that directly convert and store solar energy into electricity and have a high potential to eliminate the need for grid electricity for a sustainable future. In this study, lithiated (Li+) biphenol-based disulfonated poly (arylene ether sulfone) random copolymer (BPS) membrane has been successfully integrated into graphitic carbon nitride/zinc oxide nanowire composite-based PSC to increase the efficiency and to offer simpler and more cost-effective designs. It has been observed that after UV illumination specific capacitance (Cp) and energy density (Ed) increased 2.8 and 2.7-fold, respectively, indicating that the PSC with BPS-Li+performs approximately 3 times better under illumination than dark conditions. Furthermore, at elevated temperatures and 100% relative humidity Cp and Ed of the PSC increased to 23.61 Fg−1 and 47.22 Whkg−1 at 85 °C, respectively. This enhancement can be linked to the temperature-boosted ionic conductivity of the membrane.

Ultrahigh energy density solid state supercapacitor based on metal halide perovskite nanocrystal electrodes: Real-life applications

Inorganic lead halide perovskite nanocrystals have now become an emerging material for modern nanodevice applications. But, the huge toxicity of lead to the ecosystem has limited its applications in modern technology. In this view, a large organic cation-based metal halide perovskite may be considered the most efficient supercapacitor electrode material. Here, a new type and high molecular organic cations based low-dimensional metal halide perovskite (LDMHP) nanocrystals (NCs) are synthesized by a chemical process and their performances as supercapacitor electrode is tested. An excellent charge storage capacity and especially the Tin (Sn)-based perovskite NCs showed a very high specific capacitance and energy density of ~1536 Fg−1 and ~213 Whkg−1 at a current density of 2.0 Ag−1, respectively. The calculated variable parameter (b) value from cyclic voltammetry showed that the total capacity of the Sn-based perovskite NCs electrode is controlled by capacitor-like behaviour. The Sn NCs also found to have a very high DC dielectric constant at room temperature, possibly responsible for their superior supercapacitor performance. A solid-state supercapacitor based on synthesized NCs was used for real-life applications of supplying sufficient power to light emitting diodes (LEDs) for a long time.

Recent progress on V2O5 based electroactive materials: Synthesis, properties, and supercapacitor application

The concerns of sustainable energy rely on highly efficient renewable energy source and effective storage device. Supercapacitor is practically reliable energy storage devices with rapid charging rate, high power density, simple setup and good stability. Electrode materials have significant impacts on the performance of supercapacitors. Therefore, finding high performing electroactive material is critical concern of the area. Herein, the recent progress of vanadium pentoxide-based electroactive materials for supercapacitor application has been reviewed. Vanadium pentoxide is a potential electroactive material for supercapacitor due its mixed oxidation states, eco-friendliness, low cost, high capacitance and high energy density. But, poor conductivity and low cyclic stability are major drawbacks of the oxide which affect its electrochemical properties. This review point out different strategies of mitigating such limitations. Finally, future perspectives on V2O5-based electroactive materials for supercapacitor application have been highlighted.

Enhancing water droplet-based electricity generator by harnessing multiple-dielectric layers structure

Harvesting water energy is promising to relieve the global energy crisis and reach the aim of carbon neutrality. However, few effective technologies can make use of water droplets as a power source efficiently. The droplet-based electricity generator (DEG) with a transistor-inspired design has resulted in enhanced energy harvesting efficiency by orders of magnitude over traditional designs. Despite this, the current DEG generally features a single dielectric layer, limiting its integration with other common objects to achieve "unnoticed" energy harvesting. In this work, we report a novel design featuring multiple dielectric layers-based DEG (M-DEG) that leverages other materials, such as household glass or umbrellas, as the second dielectric layer under the surface triboelectric layer to harvest water droplet energy without interfering with the original function of both. We find that the second dielectric layer enhances the output of M-DEG because of higher equivalent capacitance and charge density. The open circuit voltage and short-circuit current are increased by 90.6% and 68.7%, respectively. The maximal short-circuit current reaches up to record-breaking 17.9 mA. Moreover, a capacitor model for M-DEG is established, which well reveals the influence of the properties of dielectric layers and droplets on the electric output, and accurately predicts the results.

Self-supporting electrodes with in situ built aniline on carbon fibers and reduced graphene oxide covalently for stable flexible supercapacitors

Practical applications of flexible electronics have challenged the stability and cycle performance of flexible supercapacitor under continuous mechanical deformation, thus flexible electrode with stable structure has to be considered to maintain high-quality performance. A covalent modification strategy is present here to improve the stability of electrodes. Graphitized carbon cloth (GCC) and reduced graphene oxide (rGO) that modified with aniline by Suzuki reaction, are covalently bonded together with the polymerization of aniline (PANI). The electrode (GCC-PANI-rGO) modified by covalent bonds is stable enough to remain 97.73 % initial specific capacitance after charge-discharge 15,000 times at 40 mA/cm2. The capacitance retention of asymmetric flexible solid supercapacitor (FSSC) prepared by GCC-PANI-rGO and GCC is 108.78 % after 10,000 times mechanical folding. The electrode formed a π-π conjugation system through Suzuki reaction possesses low charge transfer resistance (0.428 Ω), and exhibits high specific capacitance and energy density that up to 11.825 F/cm2 and 1.642 mWh/cm2 at 1 mA/cm2. The energy density of FSSC is 0.266 mWh/cm2 at 1 mA/cm2 and surpasses most FSSC based on PANI and graphene. This work gives an essential covalently synthetic strategy for flexible supercapacitor with stable electrochemical performance in application.

Scalable Polyimide-Organosilicate Hybrid Films for High-Temperature Capacitive Energy Storage.

High-temperature polymer dielectrics have broad application prospects in next-generation microelectronics and electrical power systems. However, the capacitive energy densities of dielectric polymers at elevated temperatures are severely limited by carrier excitation and transport. Herein, a molecular engineering strategy is presented to regulate the bulk-limited conduction in the polymer by bonding amino polyhedral oligomeric silsesquioxane (NH2 -POSS) with the chain ends of polyimide (PI). Experimental studies and density functional theory (DFT) calculations demonstrate that the terminal group NH2 -POSS with a wide-bandgap of Eg ≈ 6.6eV increases the band energy levels of the PI and induces the formation of local deep traps in the hybrid films, which significantly restrains carrier transport. At 200°C, the hybrid film exhibits concurrently an ultrahigh discharged energy density of 3.45Jcm-3 and a high gravimetric energy density of 2.74Jg-1 , with the charge-discharge efficiency >90%, far exceeding those achieved in the dielectric polymers and nearly all other polymer nanocomposites. Moreover, the NH2 -POSS terminated PI film exhibits excellent charge-discharge cyclability (>50000) and power density (0.39MWcm-3 ) at 200°C, making it a promising candidate for high-temperature high-energy-density capacitors. This work represents a novel strategy to scalable polymer dielectrics with superior capacitive performance operating in harsh environments.

A Solid-State Wire-Shaped Supercapacitor Based on Nylon/Ag/Polypyrrole and Nylon/Ag/MnO2 Electrodes.

In this work, a novel wire-shaped supercapacitor based on nylon yarn with a high specific capacitance and energy density was developed by designing an asymmetric configuration and integrating pseudocapacitive materials for both electrodes. The nylon/Ag/MnO2 yarn was prepared as a positive electrode by electrochemically depositing MnO2 on a silver-paste-coated nylon yarn. Additionally, PPy was prepared on nylon/Ag yarn by chemical polymerization firstly to enlarge the surface roughness of nylon/Ag, and then the PPy could be easily coated on the chemically polymerized nylon/Ag/PPy by electrochemical polymerization to obtain a nylon/Ag/PPy yarn-shaped negative electrode. The wire-shaped asymmetric supercapacitor (WASC) was fabricated by assembling the nylon/Ag/MnO2 electrode, nylon/Ag/PPy electrode and PAANa/Na2SO4 gel electrolyte. This WASC showed a wide potential window of 1.6 V and a high energy density varying from 13.9 to 4.2 μWh cm-2 with the corresponding power density changing from 290 to 2902 μW cm-2. Meanwhile, because of the high flexibility of the nylon substrate and superior adhesion of active materials, the WASC showed a good electrochemical performance stability under different bending conditions, suggesting its good flexibility. The promising performance of this novel WASC is of great potential for wearable/portable devices in the future.

An Ultra‐Thin, Ultra‐High Capacitance Density Tantalum Capacitor for 3D Packaging

AbstractAlthough embedded capacitors have been applied and researched for many years, their large‐scale application still faces challenges such as low capacitance density, high thickness, high cost, and incompatibility with integrated processes. In this work, a breakthrough has been made in the fabrication of ultra‐thin tantalum (Ta) capacitors with ultra‐high capacitance density that can be used for 3D packaging. The key to these excellent performances is the application of Ta foil with nano‐porous structure to the anode of the capacitor. The Ta foil with high specific surface area (SSA) is successfully prepared by direct current pulse etching. At a current density of 15 mA cm−2, a pulse frequency of 50 Hz, and a duty cycle of 30%, the SSA of Ta foil is increased by 76 times after etching in an electrolyte with 0.01 v% TOA for 30 min. Based on this, Ta capacitors with a form factor of less than 40 µm, showing a capacitance density of 750 nF mm−2 and a leakage current of less than 2.1 × 10−7 A at 8 V is successfully fabricated. To the best of the authors’ knowledge, this is the highest capacitance density reported to date for the mentioned form factors.

Highly flexible, foldable carbon cloth/MXene/polyaniline/CoNi layered double hydroxide electrode for high-performance all solid-state supercapacitors

Layered double hydroxide (LDH) has become one of the prospective electrode materials due to high specific area, good cycle stability and high power density. However, large internal resistance limits its application in energy storage. The introduction of materials with high electrical conductivity is expected to solve this problem. In here, carbon cloth/MXene/PANI/CoNi-LDH (CC/MXPACN) composites are fabricated by the electrodeposition of PANI and CoNi-LDH on the CC coated with MXene. The effects of electrodeposition time on the electrochemical performances are investigated in detail. The asymmetric supercapacitor is assembled with CC/MXPACN as the positive electrode and activated carbon (AC) as the negative electrode. The device has a 1.6 V voltage window. After 10,000 cycles at a current density of 5 A g−1, the capacitance retention rate is still 91 %. At the power density of 399.95 W kg−1, the energy density of 39.33 Wh kg−1 is provided. Even at the high power density of 2400.35 W kg−1, the energy density can still reach 27.27 Wh kg−1. The asymmetric device has high specific capacitance, long-term stability and good power density and energy density, which exhibit a huge potential in energy storage applications.

Potential of MnO2‐based composite and numerous morphological for enhancing supercapacitors performance

AbstractThe development of materials and electrochemical energy storage (EES) technologies are currently taking the lead and showing excellent performance in the global effort to tackle the issues of sustainable energy supply. Supercapacitors have been widely studied among the EES technologies as they exhibit quick charging rates under high‐power conditions. Manganese dioxide (MnO2) has attracted renewed interest as a promising material due to its high theoretical capacitance and high energy density. However, the widespread application is immediately impacted by low conductivity. Hence, combining nanomaterials and various morphologies of MnO2 can improve the electrochemical performance of supercapacitors. This paper presents a review based on the composites of nanomaterials/MnO2 with various morphologies. Their mechanism and practical applications in supercapacitors are introduced in detail. Finally, the challenges and next steps in developing MnO2 electrode materials are proposed.

Impact of Large Gate Voltages and Ultrathin Polymer Electrolytes on Carrier Density in Electric-Double-Layer-Gated Two-Dimensional Crystal Transistors.

Electric-double-layer (EDL) gating can induce large capacitance densities (∼1-10 μF cm-2) in two-dimensional (2D) semiconductors; however, several properties of the electrolyte limit performance. One property is the electrochemical activity which limits the gate voltage (VG) that can be applied and therefore the maximum extent to which carriers can be modulated. A second property is electrolyte thickness, which sets the response speed of the EDL gate and therefore the time scale over which the channel can be doped. Typical thicknesses are on the order of micrometers, but thinner electrolytes (nanometers) are needed for very-large-scale-integration (VLSI) in terms of both physical thickness and the speed that accompanies scaling. In this study, finite element modeling of an EDL-gated field-effect transistor (FET) is used to self-consistently couple ion transport in the electrolyte to carrier transport in the semiconductor, in which density of states, and therefore quantum capacitance, is included. The model reveals that 50 to 65% of the applied potential drops across the semiconductor, leaving 35 to 50% to drop across the two EDLs. Accounting for the potential drop in the channel suggests that higher carrier densities can be achieved at larger applied VG without concern for inducing electrochemical reactions. This insight is tested experimentally via Hall measurements of graphene FETs for which VG is extended from ±3 to ±6 V. Doubling the gate voltage increases the sheet carrier density by an additional 2.3 × 1013 cm-2 for electrons and 1.4 × 1013 cm-2 for holes without inducing electrochemistry. To address the need for thickness scaling, the thickness of the solid polymer electrolyte, poly(ethylene oxide) (PEO):CsClO4, is decreased from 1 μm to 10 nm and used to EDL gate graphene FETs. Sheet carrier density measurements on graphene Hall bars prove that the carrier densities remain constant throughout the measured thickness range (10 nm-1 μm). The results indicate promise for overcoming the physical and electrical limitations to VLSI while taking advantage of the ultrahigh carrier densities induced by EDL gating.