Tetrafluoroborate Ionic Liquid Research Articles

Structural Insight into Ionogels: A Case Study of 1-Methyl-3-octyl-imidazolium Tetrafluoroborate Confined in Aerosil.

Ionogels were obtained by impregnating Aerosil A380 with 1-methyl-3-octyl-imidazolium tetrafluoroborate (OMIM BF4) ionic liquid (IL). The IL content of the ionogels varied from 16.3 to 79.9 mol %. There was evidence of the confinement of the IL in silica in the shift and broadening of the BF4- 19F NMR signal and in the noticeable (∼50 °C) decrease in the temperature of IL decomposition. For both the ionogels and the pure IL, the frequencies of IR vibrations were different, providing further evidence of the confinement effect. An analysis of textural characteristics revealed that, upon its addition to Aerosil, the IL sequentially adsorbed in the micropores, mesopores and interparticle space. SAXS measurements showed that, in the confined IL, the size of nonpolar correlations substantially increased, from 21.5 Å in the bare IL to 25.6 Å in the ionogel containing 28.1 mol % IL. Unexpectedly, for the ionogel with the lowest IL content (16.3 mol %), no nonpolar correlations were observed, indicating the strong distortion of the structure of the confined ionic liquid. To the best of the authors' knowledge, this is the first report on regular changes in nonpolar correlations in ionic liquids upon confinement in a porous solid. These structural correlations can easily be tuned by simply changing the IL content in the ionogel material.

Plasmon-Driven Highly Selective CO2 Photoreduction to C2H4 on Ionic Liquid-Mediated Copper Nanowires.

Selective CO2 photoreduction to value-added multi-carbon (C2+) feedstocks, such as C2H4, holds great promise in direct solar-to-chemical conversion for a carbon-neutral future. Nevertheless, the performance is largely inhibited by the high energy barrier of C-C coupling process, thereby leading to C2+ products with low selectivity. Here we report that through facile surface immobilization of a 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIM-BF4) ionic liquid, plasmonic Cu nanowires could enable highly selective CO2 photoreduction to C2H4 product. At an optimal condition, the resultant plasmonic photocatalyst exhibits C2H4 production with selectivity up to 96.7 % under 450 nm monochromatic light irradiation, greatly surpassing its pristine Cu counterpart. Combined in situ spectroscopies and computational calculations unravel that the addition of EMIM-BF4 ionic liquid modulates the local electronic structure of Cu, resulting in its enhanced adsorption strength of *CO intermediate and significantly reduced energy barrier of C-C coupling process. This work paves new path for Cu surface plasmons in selective artificial photosynthesis to targeted products.

Plasmon‐Driven Highly Selective CO2 Photoreduction to C2H4 on Ionic Liquid‐Mediated Copper Nanowires

AbstractSelective CO2 photoreduction to value‐added multi‐carbon (C2+) feedstocks, such as C2H4, holds great promise in direct solar‐to‐chemical conversion for a carbon‐neutral future. Nevertheless, the performance is largely inhibited by the high energy barrier of C−C coupling process, thereby leading to C2+ products with low selectivity. Here we report that through facile surface immobilization of a 1‐ethyl‐3‐methylimidazolium tetrafluoroborate (EMIM‐BF4) ionic liquid, plasmonic Cu nanowires could enable highly selective CO2 photoreduction to C2H4 product. At an optimal condition, the resultant plasmonic photocatalyst exhibits C2H4 production with selectivity up to 96.7 % under 450 nm monochromatic light irradiation, greatly surpassing its pristine Cu counterpart. Combined in situ spectroscopies and computational calculations unravel that the addition of EMIM‐BF4 ionic liquid modulates the local electronic structure of Cu, resulting in its enhanced adsorption strength of *CO intermediate and significantly reduced energy barrier of C−C coupling process. This work paves new path for Cu surface plasmons in selective artificial photosynthesis to targeted products.

Ionic liquid regulating perovskite film for air-processed perovskite solar cells

Air-processed perovskite solar cells (PSCs) expediate its commercialization. However, since the intrinsic moisture sensitivity disturb perovskite crystallization and morphology, the photovoltaic performance and shelf stability attenuation are inevitably occurred. Herein, 1-ethy-3-methylimidazolium tetrafluoroborate ([AOEMIM][BF4]) ionic liquids (ILs) was incorporated into perovskite interior to weaken the deleterious influence of ambient moisture on perovskite crystallization. The carboxyl and imidazole from the [AOEMIM]+ moiety passivate undercoordinated Pb2+ defects through coordination bond, while hydrophobic [BF4]- incorporating into the precursor solution protects the films from moisture destruction. Consequently, the targeted PSCs fabricated in open air achieved an impressive PCE of 19.86 % with favorable shelf stability, maintaining 93 % and 89 % of their original efficiencies after 720 h under relative humidity of 80 ± 2 % and after 240 h thermal ageing measurement at 85 °C, respectively.

High selectivity and anti-interference molecularly imprinted polymer based on spheroidal carbonized polymer dots for effective sulfadiazine sodium removal

Although several methods for enhancing the selectivity of molecularly imprinted polymers (MIPs) have been reported, their effects on complex substrates remain unsatisfactory. In this study, a customised 1-vinyl-3-hydroxyethylimidazolium tetrafluoroborate ionic liquid with a vinyl double bond polymerizable unit and an F-atom recognition unit was employed as a precursor carbon source to prepare unique spherical carbonised polymer dots (CPDs-F) through an incomplete carbonisation process using the one-step hydrothermal method. Then used it as a novel functional monomer, sulfadiazine sodium (SDS), as a template to synthesize the SDS-imprinted material CPDs-F@MIP in aqueous media. The results indicated that the obtained CPDs-F@MIP exhibited excellent selectivity for the template, with an imprinting factor of up to 6.39, surpassing that of the MIPs prepared with chain functional monomers 2.12–4.76 times. The selective adsorption of the template molecule, SDS (selectivity coefficient: approximately 2.615–43.149), was not significantly influenced by the coexistence of contaminants with various structural characteristics. The maximum adsorption capacity reached 61.06 mg g−1. After at least twenty applications, the adsorption capability of CPDs-F@MIP did not decrease significantly. Finally, the prepared CPDs-F@MIP were used as solid-phase extraction adsorbents in combination with high-performance liquid chromatography, and the anti-interference ability and selective adsorption performance of CPDs-F@MIP in six actual water samples were investigated. Additionally, an accurate, reliable method for detecting SDS in environmental water was established (limit of detection of 0.2 μg L−1, and the recoveries ranged from 91.79% to 111.32%). Imprinting materials prepared using spherical functional monomers significantly enhance their selective recognition ability in complex media and provide new ideas for the preparation and application of novelty imprinting materials with superior performance.

Ti3C2Tx Filled in EMIMBF4 Semi-Solid Polymer Electrolytes for the Zinc-Metal Battery.

Zinc-ion batteries (ZIBs) are promising candidates for safe energy storage applications. However, undesirable parasitic reactions such as dendrite growth, gas evaluation, anode corrosion, and structural damage to the cathode under an acidic microenvironment severely affected cell performance. To resolve these issues, an MXene entrapped in an ionic liquid semi-solid gel polymer electrolyte (GPE) composite was explored. The molecular-level mixing of poly(vinylidene fluoride-co-hexafluoropropylene) (PVHF), zinc trifluoromethanesulfonate (Zn(OTF)2), 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4) ionic liquid, and Ti3C2Tx MXene provided a controlled Zn2+ shuttle toward the anode/cathode. Ti3C2Tx/EMIBF4/Zn(OTF)2/PVHF exhibited a breaking strength of 0.36 MPa with an associated extension of 23%. The Zn//Ti3C2Tx/EMIBF4/Zn(OTF)2/PVHF//Zn symmetric cell with continuous zinc plating/stripping exhibited excellent Zn2+ ion mobility toward the anode and cathode without undesired reactions. This was confirmed by post-mortem analysis after a symmetric cell compatibility test. The as-prepared GPE with a Na3V2(PO4)3 (NVP) cathode exhibited a high chemical diffusion coefficient of 1.14 × 10-7. It also showed an outstanding reversible capacity of 89 mAh g-1 at C/10 with an average discharge plateau voltage of 1.45 V, cycle durability, and controlled self-discharge. These results suggested that the Zn2+ ions in the Ti3C2Tx/EMIBF4/Zn(OTF)2/PVHF composite are reversibly labile in the anode and cathode directions.

Rapidly Grown Hexagonal Organic Microtubes Using Ionic Liquids for an Enhanced Optical Waveguide Effect

AbstractAn optical waveguide that transmits the electromagnetic waves is a critical component for various optoelectrical applications including integrated optical circuits and optical communications. Among many, the 1D tubular optical waveguide structure enables efficient distant energy transfer via mode selection within the optical microcavity. However, its application is limited due to the complicated fabrication process. Herein, hexagonal tris(8‐hydroxyquinoline) aluminum (Alq3) microtubes with an average longitudinal length of ≈15 µm are self‐assembled within few minutes by utilizing 1‐butyl‐3‐methylimidazolium tetrafluoroborate (BMIMBF4) ionic liquids. The swift fabrication is enabled by the high electron affinity of BMIMBF4 that forms hexagonal microrods. Also, BMIMBF4 ionic liquid etches the central region of micorods during its growth, forming microtubes with a wall thickness of ≈650 nm. The fabricated Alq3 microtubes show significantly improved waveguide characteristics with reduced optical loss coefficient (0.054 µm−1) compared to that of microrods (0.271 µm−1). The demonstrated method to fabricate Alq3 microtubes with ionic liquid is an efficient approach to utilize organic microstructures as an optoelectrical components for advanced optical communications.

Experimental studies on thermal conductivity and heat transfer of 1-Butyl-3-methylimidazolium tetrafluoroborate ionic liquid and its nanocolloids

This paper outlines and discusses the thermal conductivity of 1-Butyl-3-methylimidazolium tetrafluoroborate ionic liquid, as well as three classes of nanocolloids. The [C4mim][BF4] ionic liquid was enhanced with three kinds of nanoparticles, Al2O3, ZnO and MWCNT and all fluids thermal conductivity was experimentally measured. Results discussion includes also an in-depth analysis on Prandtl number and thermal diffusivity. All the data were carefully debated in terms of state of the art advancement and these suspensions suitability for practical applications in heat transfer. It was found that the thermal conductivity increases with nanoparticles addition and this enhancement depends on nanoparticle type and temperature. Plus, the temperature influence is rather limited, while the consideration on Prandtl number and thermal diffusivity revealed that it is extremely relevant to consider all the thermophysical properties when choosing a new thermal fluid. Additionally, a comparison with well known correlations was inserted, concluding that no theory can estimate the ionic liquids nanocolloids thermal conductivity. Concluding, the thermal properties of [C4mim][BF4] ionic liquid and its nanocolloids with Al2O3, ZnO and MWCNT shows that these nanocolloids uncover great potential for heat transfer applications.

Pyrrolidinium Derivative‐Based Ionic Liquid Achieves Defect Passivation for Efficient Perovskite Solar Cells Exceeding 23%

In the rapidly developing field of photovoltaics, organic–inorganic metal halide perovskites are outstanding for their exceptional power conversion efficiencies (PCE), exceeding 26%. However, the full potential of these materials is often undermined by the prevalence of defects within their structure and at the grain surfaces, leading to significant nonradiative recombination losses. To meet this critical challenge, this study introduces a novel strategy involving a pyrrolidinium derivative and tetrafluoroborate ionic liquid, specifically 2‐pyrrolidin‐1‐ium‐1‐ethylammonium tetrafluoroborate (PyE(BF4)2), as an additive in the perovskite precursor. This approach aims to meticulously control crystallization processes and effectively passivate defects on the surface and grain boundaries of the perovskite. The formation of N─H…I− hydrogen bonds and strong ionic interactions, PyE(BF4)2 not only stabilizes the [PbI6]4− framework but also optimizes the valence band alignment with the hole transport layer. Empirical results demonstrate that perovskite solar cells modified with PyE(BF4)2 have achieved a notable PCE of 23.80% and remarkable stability exceeding 1300 h under standard testing protocols (ISOS‐V‐1). The findings emphasize the transformative potential of multifunctional ionic liquids in enhancing the performance and durability of perovskite‐based photovoltaic devices, marking a significant step forward in pursuing sustainable and efficient solar energy solutions.

Interface modification for efficient carbon-electrode CsPbI2Br perovskite solar cells using ionic liquid.

All-inorganic CsPbI2Br, as a promising photovoltaic (PV) material, have attracted extensive research attention in society for its outstanding thermal stability and appropriate trade-offs. Carbon-based perovskite solar cells (C-PSCs) without hole transporting layer (HTL) have shown great potential in terms of cost-effectiveness and stability. However, the inevitable defects on the surface of CsPbI2Br films severely hampers the development of high-efficiency CsPbI2Br C-PSCs. Surface engineering has emerged an effective approach to overcome this challenge. Herein, 1-decyl-3-methylimidazolium tetrafluoroborate (DMTT) ionic liquid was introduced between CsPbI2Br and carbon electrode to reduce non-recombination of charges, decrease defect states, minimize the energy-level mismatch, and greatly enhance the device stability. As a result, the HTL-free CsPbI2Br C-PSCs combined with DMTT as an interface modification achieved a higher power conversion efficiency (PCE) of 12.47% than that of the control devices with a PCE of 11.32%. Furthermore, without any encapsulation, the DMTT-optimized C-PSC remained approximately 84% of its initial PCE after over 700 h under room temperature and 25% relative humidity (RH) conditions. Additionally, when exposed to a temperature of 65 °C for over 400 h, the device still retained 74% of the initial PCE, demonstrating its thermal stability.

Experimental Measurements, Correlation, and Prediction Models to Study 1-Ethyl-3-methylimidazolium Tetrafluoroborate Ionic Liquid Ternary Mixtures

Experimental Measurements, Correlation, and Prediction Models to Study 1-Ethyl-3-methylimidazolium Tetrafluoroborate Ionic Liquid Ternary Mixtures

Enhancing the performance of PbS:CsPbBr3 bulk-heterojunction photodetectors by treating with imidazolium-based ionic liquids.

All-inorganic lead halide perovskites and quantum dots (QDs) have gained significant attention since their emergence, owing to their immense potential for applications in optoelectronic devices. Here, enhanced-performance broadband photodetectors based on the bulk-heterostructure of a CsPbBr3 perovskite and PbS colloidal quantum dots (CQDs) are presented, and 1-ethyl-3-methylimidazolium tetrafluoroborate ([EMIM]BF4) ionic liquids as a dual-purpose additive were introduced in the blended film to regulate the surface of QDs by facilitating surface passivation, adjusting energy levels, and coupling with longer alkyl chains as compared to iodide ions (I-). As a result, a superior-quality bulk-heterostructure based photodetector with long-term stability was obtained, showing outstanding performance in photodetection across the visible to near-infrared wavelength range, demonstrating a high photoresponsivity of 22.4 A W-1 with a response time of 16.2 ms and a specific detectivity of 1.58 × 1014 Jones under 405 nm illumination. Thus, this work provides a novel modification strategy for PbS:CsPbBr3 as a promising material for novel optoelectronics.

Ionic liquid-functionalized antibiofouling nanofiltration membranes

Nanofiltration membranes hold great potential for water treatment applications, but are susceptible to fouling issues. In this study, we demonstrate the fabrication of NF membranes with high permeability, high rejection, antibiofouling and scaling resistance. The membrane was prepared through interfacial polymerization by doping the aqueous phase with 1-aminoethyl-3-methylimidazolium tetrafluoroborate ionic liquid. The TFC-0.2 membrane exhibited a more open nanoporous structure, resulting in an increased permeability from 5 ± 0.5 L·m−2·h−1·bar−1 (LMH/Bar) to 11.1 ± 0.4 LMH/Bar, while maintaining a comparable salt rejection performance to the original TFC membrane. Additionally, the TFC-0.2 membrane demonstrated excellent retention performance, with a removal efficiency exceeding 90 % for emerging contaminants such as antibiotics and PFOA. Notably, the TFC-0.2 membrane exhibited significant differences in the rejection of Na2SO4 and CaCl2, indicating its strong resistance to gypsum fouling. Furthermore, it is worth highlighting that the TFC-0.2 membrane displayed remarkable antibiofouling performance due to the bactericidal properties of AMIT. This capability allowed for the sterilization of bacteria at the early stage of attachment to the membrane surface, effectively mitigating biofouling. The findings of this study offer a simple yet effective strategy for fabricating high-performance nanofiltration membranes with exceptional antifouling properties.

Solvation behavior of phenolic pollutants in aqueous solutions of imidazolium-based ionic liquids: A molecular dynamics simulations study

In this study, the solvation behavior of phenolic pollutants (PPs) in 1-octyl-3-methylimidazolium tetrafluoroborate ([C8MIM][BF4]) ionic liquid (IL) aqueous solutions was simulated using molecular dynamics (MD) simulations. The study found that the cationic part of IL was the most interactive and played the most important role in the extraction of PPs. It also demonstrated that stronger hydrophobic interactions between PPs and the cationic portion resulted in higher extraction efficiency, with the exception of resorcinol, whose stronger hydrogen bonds (HBs) with water molecules reduced extraction efficiency. The study discovered that van der Waals forces governed interaction energies (IEs) between PPs and ILs, while HBs played a minor role. Since the cationic part plays a major role in the extraction process of PPs, the efficiency of the extraction process can be improved by making structural changes to this part.

Nitrogen-doped agar-derived porous carbon with long cycle life for high-performance ionic liquid-based supercapacitors

Reasonable design of electrode materials to match ionic liquid electrolytes is important for the development of high-performance supercapacitors in the future. Herein, we demonstrate a nitrogen-doped agar-derived porous carbon (NAGC) electrode material with high specific capacitance and long cycling life, which was prepared using agar as precursor, potassium carbonate as activator, and melamine as nitrogen source via one-step activation doping method. The combined action of melamine and potassium carbonate can regulate and control the physical and electrochemical properties of the prepared materials. NAGC presents a high specific surface area (3228 m2/g) and micropores-dominated hierarchical porous structure, which can provide more adsorption sites and benefit rapid ions transport. The NAGC electrode in 1-ethyl-3-methylimidazolium tetrafluoroborate ([Emim][BF4]) ionic liquid electrolyte has a specific capacitance of 183 F/g at 1 A/g and 91 % capacitance retention from 1 to 10 A/g. Additionally, the assembled device with NAGC as both positive and negative electrode material has a wide operating voltage (3.6 V) and high energy density of 70.2 Wh/kg at a power density of 1.81 kW/kg. Also, it possesses a capacitance retention of 83.3 % after 50,000 cycles. This work provides a simple and effective way to achieve porous carbon materials with high specific capacitance and long cycle life.

Investigation on two-dimensional molybdenum oxide-graphitic carbon nitride (MoO3-g-C3N4) heterostructures based hybrid electrodes for the fabrication of high energy density solid state supercapacitors

BackgroundThe fabrication of high-performance supercapacitor electrodes has been extensively investigated for future high power storage applications. Molybdenum trioxide (MoO3) was synthesized and the graphitic carbon nitride have been introduced with the MoO3 to enhance the electrochemical performance by synergistic effect. MethodsMoO3-gC3N4 Nanocomposite (NC) was synthesized by thermal treatment followed by sonication process and can be utilized as active material for the preparation of supercapacitor electrode. The solid-state hybrid supercapacitor device (SHSC) is fabricated with MoO3-gC3N4 NC as cathode, activated carbon as anode, and 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4) ionic liquid as an ionogel electrolyte to perform the electrochemical studies. Significant findingsCyclic voltammetry (CV) revealed that the synthesized composite delivers higher specific capacity of 520. 97 C/g at 10 mV/s. The electrochemical impedance spectroscopy (EIS) of MoO3-g-C3N4 NC reveals lower solution (Rs) and charge transfer resistance (Rct) of 0.05 and 3.14 Ω respectively. The fabricated MoO3-g-C3N4//AC SHSC delivers high energy density of 59.75 Wh/kg and a high-power density of 1125 W/kg. Furthermore, the SHSC exhibits superior cyclic stability of 86.1% even after 6000 consecutive charge-discharge cycles.

An Efficient Electrochemical Sensor Based on NiCo2O4 Nanoplates and Ionic Liquid for Determination of Favipiravir in the Presence of Acetaminophen.

Based on the modification of carbon paste electrode with NiCo2O4 nanoplates and 1-hexyl-3-methylimidazolium tetrafluoroborate, a new electrochemical sensing platform for the sensing of favipiravir (a drug with potential therapeutic efficacy in treating COVID-19 patients) in the presence of acetaminophen was prepared. For determining the electrochemical behavior of favipiravir, cyclic voltammetry, differential pulse voltammetry, and chronoamperometry have been utilized. When compared to the unmodified carbon paste electrode, the results of the cyclic voltammetry showed that the proposed NiCo2O4 nanoplates/1-hexyl-3-methylimidazolium tetrafluoroborate/carbon paste electrode had excellent catalytic activity for the oxidation of the favipiravir in phosphate buffer solution (pH = 7.0). This was due to the synergistic influence of 1-hexyl-3-methylimidazolium tetrafluoroborate (ionic liquid) and NiCo2O4 nanoplates. In the optimized conditions of favipiravir measurement, NiCo2O4 nanoplates/1-hexyl-3-methylimidazolium tetrafluoroborate/carbon paste electrode had several benefits, such as a wide dynamic linear between 0.004 and 115.0 µM, a high sensitivity of 0.1672 µA/µM, and a small limit of detection of 1.0 nM. Furthermore, the NiCo2O4 nanoplates/1-hexyl-3-methylimidazolium tetrafluoroborate/carbon paste electrode sensor presented a good capability to investigate the favipiravir and acetaminophen levels in real samples with satisfactory recoveries.

Unraveling the Ag+ ion coordination and solvation thermodynamics in the 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid

The solvation of the Ag+ ion in the 1-butyl-3-methylimidazolium tetrafluoroborate ([C4mim][BF4]) ionic liquid (IL) has been studied by means of experimental and theoretical methods with the aim of elucidating the cation coordination structure and thermodynamic properties. Car-Parrinello molecular dynamics (CPMD) simulations showed that the Ag+ ion is coordinated by an average number of four [BF4]− anions in a pseudo-tetrahedral geometry. A high configurational disorder of the first solvation sphere is found, where the anions can be found both in mono- and bidentate coordination mode around the Ag+ ion. Also, a solvational equilibrium is observed as due to [BF4]− anion dissociation along the trajectory. The analysis of X-ray absorption spectroscopy data confirmed the picture provided by the CPMD simulation. Classical molecular dynamics simulations were carried out to obtain the single-ion solvation thermodynamic parameters. The negative water → IL free energy of transfer suggests that the Ag+ ion is more favorably solvated in the [C4mim][BF4] IL than in water. This behavior is due to a balance between the enthalpic and entropic contributions, which allows to find a rationale to the strong solvation capabilities of BF4-based ILs towards Ag+.

Inorganic-Organic Double Network Ionogels Based on Silica Nanoparticles for High-Temperature Flexible Supercapacitors.

Herein, we demonstrate an inorganic-organic double network gel electrolyte consisting of a silica particle network and a poly-2-hydroxyethyl methacrylate network in which 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquids are confined. The as-synthesized double network ionogel electrolytes exhibited high ion conductivity of 3.8 to 12.8 mS cm-1 over a wide temperature range of 30 to 150 °C and mechanical integrity with a maximum toughness of 1.8 MJ m-3 at 30 °C. These remarkable properties of the ionogel were associated with the formation of an optimal physical network of the silica nanoparticles in the colloidal dispersion. Accordingly, a flexible supercapacitor using ionogel electrolytes and reduced graphene oxide electrodes delivered energy and power densities of 48 Wh kg-1 and 4 kW kg-1, respectively, even at a high temperature of 120 °C, demonstrating excellent long-term stability that retains 93% of the initial capacitance even over 10,000 charge/discharge cycles at 120 °C.

Efficient electrochemical energy storage designed by second alcoholic fermentation of rice

Supercapacitors can deliver energy quickly, offering extraordinary potential for efficient electrochemical energy storage (EES) systems. Specifically, carbon-based supercapacitors have reliable operational stability and outstanding cycle lifespans. However, designing low-cost and high-energy-density carbon electrode materials using a simple method remains an enormous challenge. Here, we design a porous carbon material JKPC-4-700 derived from a second alcoholic fermentation rice by tuning the pore sizes using a simple approach. The main pore sizes of JKPC-4-700 are 0.57 and 1.22 nm, in good agreement with the 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIMBF4) ionic liquid. The specific surface area of JKPC-4-700 reaches 2662 m2 g−1, which enables JKPC-4-700 a specific capacity of 465 F g−1 (at 1.0 A g−1 in 6 M KOH). The symmetric capacitors based on JKPC-4-700 deliver an excellent energy density of 117 Wh kg−1 (at a power-density of 900 W kg−1). Our research offers a new strategy for developing high-energy-density, low-cost, and functional carbon materials for efficient EES systems.