Electrolytes For Supercapacitors Research Articles

Electronic Booster PEDOT:PSS-Enriched Guar Gum as Eco-Friendly Gel Electrolyte for Supercapacitor

Electronic Booster PEDOT:PSS-Enriched Guar Gum as Eco-Friendly Gel Electrolyte for Supercapacitor

Application of N/P-rGO composite electrode materials and novel electrolytes in high-performance supercapacitors

Traditional graphene-based electrode materials often can not have excellent gravimetric and volumetric electrochemical properties at the same time. Furthermore, the gel electrolyte widely used at present has the disadvantages of poor water retention, easy solidification, low ionic conductivity, and narrow working temperature range during the working process. In this paper, nanocellulose/N, P co-doped reduced graphene oxide composites (NC-NPrGOs) were synthesized via a simple approach using graphene oxide (GO), ammonium dihydrogen phosphate, and nanocellulose (NC) as raw materials. Meanwhile, a new type of gel electrolyte (SNG) with renewable, wide working temperature range and ultra-high water retention properties was prepared using sodium alginate (SA), NC, GO, and potassium hydroxide as precursors. Benefiting from the unique physical and chemical properties of NC-NPrGOs, the assembled aqueous symmetric supercapacitors assembled by NC-NPrGOs present high gravimetric (303.9 F/g) and volumetric specific capacitance (416.5 F cm−3), large gravimetric (10.5 Wh kg−1) and volumetric energy density (14.6 Wh/L). Due to the multiple interactions of several components in SNG, the flexible solid-state supercapacitors (ASSC) assembled by NC-NPrGO55 and SNG deliver high specific capacitance (240.0 F/g), ultra-long cycling life, excellent bending resistance, a wide range of operating temperatures, and good regenerative performance. In summary, NC-NPrGOs and SNGs are ideal for the investigation of new energy storage devices.

Novel approach: Simultaneous application of ionic liquid doped polymer electrolyte in supercapacitor and dye-sensitized solar cells

The present study reports the synthesis, characterization, and application as energy devices of an ionic liquid blended polymer electrolyte film in which the host polymer polyvinyl alcohol (PVA) is mixed with low viscosity ionic liquid (IL) 1-ethyl-3-methylimidazolium thiocyanate. Various characterization tools have been used further to elaborate electrical, structural, and photoelectrochemical properties. X-ray diffraction (XRD) and polarized optical microscope (POM) affirm the reduction of crystallinity of polymer, while Fourier transform infrared spectroscopy (FTIR) shows complexation and composite nature. Electrochemical impedance spectroscopy shows an enhancement in ionic conductivity by IL doping, where the highest conductivity is achieved at 60 wt% of IL concentration with a conductivity value of 6.21 × 10⁻⁴ S/cm. The ionic transference number (tion) and electrochemical stability measurement show the film's predominantly ionic nature and a reasonable stability window. Using maximum conducting film sandwiched between electrodes, we have successfully fabricated two devices, i.e., an electrical double-layer capacitor (EDLC) and a dye-sensitized solar cell (DSSC). The fabricated EDLC capacitor shows a specific capacitance of 125 F/g, while DSSC shows an efficiency of 1.1 % at one sun condition.

A Comprehensive Review of Novel Emerging Electrolytes for Supercapacitors: Aqueous and Organic Electrolytes Versus Ionic Liquid-Based Electrolytes

A Comprehensive Review of Novel Emerging Electrolytes for Supercapacitors: Aqueous and Organic Electrolytes Versus Ionic Liquid-Based Electrolytes

Synergistic effect of MnS@Bi2S3 nanosheets for enhanced electrochemical performance in aqueous electrolyte supercapacitor application

With the low electronegativity of sulfur to oxygen, metal sulfides have become of much interest in energy storage system application, due to their high redox reactive sites and structure stability. However, composite of two or more metal sulfides is considered one of the strategies to improve the electrochemical properties, by utilizing the synergistic effect of the individual metal sulfides components. Here, MnS@Bi2S3 composites were obtained via three-step hydrothermal synthesized method. The MnS@Bi2S3 composite exhibited superior electrochemical performance with specific capacitance 185 F g−1, compared to MnS (22 F g−1) and Bi2S3 (45 F g−1) at current density 1 A g−1. Additionally, after 5000 cycles, MnS@Bi2S3 exhibited superior capacitance retention of 92 % compared to 40 % and 73 % for MnS and Bi2S3, respectively. The superior performance of MnS@Bi2S3 composite can be attributed to its higher specific surface area and the synergistic effect of MnS and Bi2S3.

Molecular insight into sequence-defined polyelectrolytes for energy storage devices

Polyelectrolyte (PE) adsorption on charged surfaces is a complex phenomenon that has an array of applications ranging from healthcare to designing energy storage devices. PE adsorption on surfaces involves surface charge polarization effects which arise due to the dielectric dissimilarities between the PE and the charged surface. PEs owing to their high potential window, and leakage-resistant behavior are used as supercapacitor electrolytes. Recent experimental evidence suggests co-block polymers as potential design materials for energy storage devices (ESDs). It is imperative to mention that the structural variation of the co-block polymers under spatial confinements will have a key role in designing electrodes and electrolytes for ESDs which demands a detailed investigation. This study reveals that the spatial orientations of the charged groups have an impressive impact on the changes in PE charge density peaks, charge amplification peaks, PE adsorption, counter-ion adsorption, and differential and integral capacitance while confined by graphene electrodes. It is startling to observe that the counter-ion distribution within the electrical double layer of the positively charged surface significantly depends on the orientation of the PEs. However, with increasing solvent dielectric constant the variations in the above-mentioned properties subside due to reduced electrostatic interactions. The differential capacitance and the integral capacitance are also found to be dependent on the dielectric constants of the solvent. These findings will be immensely useful in determining the key factors needed to describe the preferred spatial configuration of a PE suitable for various ESDs and applications involving PEs in a confined system.

Synthesis and self-assembly of bottlebrush block copolymer electrolytes for solid-state supercapacitors

All-solid-state supercapacitors have attracted increasing attention in recent decades owing to rapid advancements in safe, flexible, and wearable energy storage devices. This study demonstrates a bottlebrush block copolymer electrolyte consisting of poly(styrene-b-butadiene-b-styrene)-g-poly(ethylene glycol) behenyl ether methacrylate (SBS-g-PEGBEM) (simply SgP) for all-solid-state supercapacitors. Due to the adhesive nature and robust mechanical properties of SgP film, devices can be manufactured without the need for separators or packaging. The nonpolar SBS domains serve as scaffolds within the polymer matrix, while the polar PEGBEM domains offer interactive sites for polar ionic liquids (ILs). The synergy between precisely defined nanostructures and the subsequent well-dissociated ions enhances efficient ion transport through the ionic channels. As a result, the supercapacitor with SgP/IL electrolyte exhibits remarkable electrochemical performance. This includes a wide potential window of 2.4 V, an ionic conductivity of 2.4 mS cm−1, and maximum energy density and power density of 28.1 Wh kg−1 and 3080 W kg−1, respectively. The supercapacitor also demonstrates high cycle stability with 87.7 % capacitance retention after 5,000 cycles. The positive impact of the PEGBEM side chains is investigated via molecular dynamics simulations. Thus, this study presents a novel strategy for solid-state electrolytes, offering potential advancements in next-generation energy storage devices.

Polymeric Hydrogels for Energy Devices

Innovative energy storage devices, viz., supercapacitors and rechargeable batteries are of great awareness owing to their comprehensive claims in flexible electronics and implantations. In simple electronic devices, frequently facing problems like bending, collision, steeping, piercing, and even encountering shearing, fire, water, etc. Hence, a high mandate is needed for the constructive and consistency of energy storage devices. Hydrogels are hydrophilic three-dimensional polymers filled with water which are highly noticeable electrolyte materials due to their high-water permeability and smoothness, which enable them to fulfil the vital necessities for flexible energy storage devices. Hydrogels with intriguing physicochemical assets for justifiable energy storing for water production. The proposal of novel hydrogel electrolytes for supercapacitors and batteries with electrochemical performances for imminent growth. The biopolymeric hydrogel electrolytes can be chosen as substitute materials for supercapacitors due to their decent ionic conductivity, no fluid seepage, and no toxicity. Focus of the review aims to highlight the hydrogels materials combined into batteries and deliver thrilling tailorable architectures for multifunctionalities with amicable applications.

Recent Advances in Biopolymer-Based Hydrogel Electrolytes for Flexible Supercapacitors.

Growing concern regarding the impact of fossil fuels has led to demands for the development of green and renewable materials for advanced electrochemical energy storage devices. Biopolymers with unique hierarchical structures and physicochemical properties, serving as an appealing platform for the advancement of sustainable energy, have found widespread application in the gel electrolytes of supercapacitors. In this Review, we outline the structure and characteristics of various biopolymers, discuss the proposed mechanisms and assess the evaluation metrics of gel electrolytes in supercapacitor devices, and further analyze the roles of biopolymer materials in this context. The state-of-the-art electrochemical performance of biopolymer-based hydrogel electrolytes for supercapacitors and their multiple functionalities are summarized, while underscoring the current technical challenges and potential solutions. This Review is intended to offer a thorough overview of recent developments in biopolymer-based hydrogel electrolytes, highlighting research concerning green and sustainable energy storage devices and potential avenues for further development.

Eco-friendly Functionalization of MWCNTs with Deep Eutectic Solvents

The unique features of deep eutectic solvents (DESs) have sparked interest in their use for various applications due to their capacity to introduce new functional groups and other surface alterations. In this study, DESs were employed for the surface modification of MWCNTs. Twelve distinct varieties of Choline chloride-based DESs were prepared and characterized. Prior to the MWCNTs functionalization process, further tests, including viscosity, density, and TGA analysis, were carried out to evaluate the stability of the prepared solvents. The surface functionalization of MWCNTs was then carried out using the most stable solvent. The DESs-functionalized samples were tested for dispersibility and solubility, and FTIR was used to confirm the functional groups present. In comparison to the pristine MWCNTs, the result showed that samples D1, D2, and D4 had several functional groups on their surfaces. Also, in comparison to other DESs-functionalized samples, D1, D2, and D4 had more oxygen-containing groups, as further corroborated by CHNS analysis.As a result, DESs comprising glycerol and ethylene glycol provide an environmentally benign route to alter the surface of MWCNTs, making them suitable functional materials for a range of uses such as Adsorbents, Catalysts, Li batteries, EMI shielding materials, and Supercapacitor electrolytes.

Expression of concern: “Deep eutectic solvents: Viable sustainable electrolytes for supercapacitors”, Materials Today Energy, available online 6 October 2023, 101432

Expression of concern: “Deep eutectic solvents: Viable sustainable electrolytes for supercapacitors”, Materials Today Energy, available online 6 October 2023, 101432

Ionic liquid electrolyte selection for high voltage supercapacitors in high-temperature applications.

Systematic analyses of electrolyte physicochemical properties are important to screen ionic liquids (ILs) and understand the electrochemical performance of supercapacitor electrolytes. This study harmonizes the evaluation of electrochemical performance and transport properties of eight shortlisted ILs from 22 commercially available hydrophobic ILs toward achieving a 5V supercapacitor capable of high-temperature operation (up to 353.15K). The eight ILs are N-Propyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ([Pyr 1, 3] [TFSI], N-Pentyl-N-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide ([Pyr 1, 5] [TFSI]), N-Propyl-N-methylpyrrolidinium bis(fluorosulfonyl)imide ([Pyr 1, 3] [FSI]), 1-Methyl-1-(2-methoxyethyl)pyrrolidinium Bis(trifluoromethanesulfonyl)imide ([Pyr 1, 102] [TFSI]), 1-Methyl-1-propylpiperidinium bis(trifluoromethanesulfonyl)imide ([Pip 1, 3] [TFSI]), 1-Methyl-1-propylpiperidinium bis(fluorosulfonyl)imide ([Pip 1, 3] [FSI]), N-Trimethyl-N-propylammonium bis(trifluoromethanesulfonyl)imide ([N 111, 3] [TFSI]), N-Trimethyl-N-hexylammonium bis(trifluoromethanesulfonyl)imide ([N 111, 6] [TFSI]). The density, viscosity, and ionic conductivity of the eight ILs were measured between 278.15 and 373.15K to confirm the effects of temperature and ion structure before electrochemical characterization. The [FSI]-based ILs ([Pip 1, 3] [FSI] and [Pyr 1, 3] [FSI]) showed lower densities and viscosities compared to other ILs among the eight based on [TFSI]. Consequently, the highest conductivity was obtained for [Pyr 1, 3] [FSI]. Cyclic voltammetry and impedance spectroscopy was performed on supercapacitors assembled with the eight ILs as electrolytes between 298.15-353.15K. Conclusion from the two-electrode supercapacitors using multi-walled carbon nanotubes showed the 6 most-applicable ILs towards the targeted ≥ 5V SC at high temperature are [Pip 1, 3] [TFSI] (5.4V), [Pip 1, 3] [FSI] (5V), [N 111, 3] [TFSI] (5.1V), [N 111, 6] [TFSI] (5.2V), [Pyr 1, 102] [TFSI] (5.2V), and [Pyr 1, 5] [TFSI] (5.2V).

Epoxy-based multifunctional solid polymer electrolytes for structural batteries and supercapacitors. a short review.

The potential applications of epoxy-based solid polymer electrolytes are continually expanding because of their versatile characteristics. These characteristics include mechanical rigidity, nonvolatility, nonflammability, and electrochemical stability. However, it is worth noting that pure epoxy-based solid polymer electrolytes inherently exhibit lower ion transport capabilities when compared to traditional liquid electrolytes. Striking a balance between high mechanical integrity and superior ionic conductivity at room temperature poses a significant challenge. In light of this challenge, this review is dedicated to elucidating the fundamental concepts of epoxy-based solid polymer electrolytes. It will explore various preparation techniques, the incorporation of different nanomaterials into epoxy-based solid polymer electrolytes, and an evaluation of their multifunctional properties. This comprehensive evaluation will cover both mechanical and electrical properties with a specific focus on their potential applications in batteries and structural supercapacitors.

Low Viscosity Ionic Liquids as Novel Dopants in Poly (Methyl Methacrylate) Polymer Electrolyte: Detailed Photoelectrochemical Studies

Background: A propitious electrolyte for supercapacitors, solid polymer electrolytes (SPEs) has been used because of their flexibility and highly conducting good electrode-electrolyte interface. Poly (methyl methacrylate) (PMMA)-based SPEs have acknowledged extensive interest due to their integrity in synthesis, good mechanical stability, low binding energy, low mass density with ionic salts, and magnificent charge carrier mobility. Interesting ionic liquids show their novelty towards conductivity enhancement and suppressing crystallinity i.e. acts as a plasticizer as well as an ionic source. Due to these advantageous properties, ionic liquids (ILs) seem to be a good player in developing highly efficient electrochemical devices. Method: To overcome the low ionic conductivity (σ) and poor mechanical stability. ILs assume to be novel candidates. This review is toward defining the role of ILs as plasticizers, not as a solvent. Result: Due to the widespread applicability of these ILs, we focus our review on taking a common example of polyether i.e. PMMA using the solution cast method. Electrical and electrochemical are also discussed in detail. Conclusion: On the the basis of electrical and photoelectrochemical performance reported in this article, we can assure the scientific community that ILs can act as a potential candidate like a plasticizer for highly efficient electrochemical devices.

Phosphonate-based supercapacitor electrolyte integrating the advantages of flame retardancy, extreme temperature adaptability, and anti-supergravity

Traditional acetonitrile-based organic electrolytes continue to dominate in carbon-based supercapacitors due to their high performance-to-price ratio. However, its flammability, low extreme temperature applicability, and unknown anti-supergravity limit its application in some special scenarios (e.g., space exploration). For the first time, an electrolyte system based on potassium hexafluorophosphate (KPF6) and diethyl ethylphosphonate (DEEP) as the electrolyte salt and solvent, respectively, was proposed. The KPF6/DEEP system combines excellent flame retardancy, high capacitance performance at high (60 °C) and low (-70 °C) temperatures, anti-supergravity (60 G), and an operating voltage of up to 3.0 V, resulting in a stable and high power energy output of up to 16 Wh kg−1 for carbon-based supercapacitors at −60 °C. These benefits are primarily attributed to the distinct physical properties of DEEP (e.g., flame retardancy, low freezing point, high boiling point, and high compatibility with KPF6). Such outstanding overall performance, which incorporates excellent flame retardancy, extreme temperature adaptability, anti-supergravity, and cycle stability (capacity retention > 95 % after 14,000 cycles), outperforms the traditional acetonitrile-based system, opening up a new option for power devices for some applications with extreme environmental demands.

Tough Hydro-Aerogels with Cation Specificity Enabled Ultra-High Stability for Multifunctional Sensing and Quasi-Solid-State Electrolyte Applications.

The anion-specific effects of the salting-in and salting-out phenomena are extensively observed in hydrogels, whereas the cation specificity of hydrogels is rarely reported. Herein, a multi-step strategy including borax pre-gelation, saline soaking, freeze-drying, and rehydrating is developed to fabricate polyvinyl alcohol gels with cation specificity, exhibiting the specific ordering of effects on the mechanical properties of gels as Ca2+ > Li+ > Mg2+ >> Fe3+ > Cu2+ >> Co2+ ≈ Ni2+ ≈ Zn2+ . The multiple effects of the fabrication strategy, including the electrostatic repulsion among cations, skeleton support function of graphene oxide nanosheets, and water absorption and retention of ions, endow the gels with the dual characteristics of hydrogels and aerogels (i.e., hydro-aerogels). The hydro-aerogels prepared with the cationic salting-out effect display attractive pressure sensing performance with excellent stability over 90 days and enable continuous monitoring of ambient humidity in real-time and effective work in seawater to detect various parameters (e.g., depth, salinity, and temperature). The hydro-aerogels prepared without borax pretreatment or using the cationic salting-in effect can serve as quasi-solid-state electrolytes in supercapacitors, with 99.59% capacitance retention after 10000 cycles. This study realizes cation specificity in hydrogels and designs multifunctional hydro-aerogels for promising applications in various fields.

Aniline-substituted viologen-containing redox-active electrolytes for supercapacitors

Supercapacitors using the electrolyte containing aniline-substituted viologen were fabricated, and the effects of the substitution number of the aniline group on viologen materials were studied. The electrolyte mainly comprised 1-ethyl-3-methylimidazolium bis(trifluoromethyl sulfonyl) imide, dimethyl ferrocene, and the aniline-substituted viologens. As-synthesized aniline monomer, aniline dimer, and aniline trimer were used to substitute into the nitrogen site of the viologen molecule. The areal capacitance value of aniline dimer substituted viologen was 5.81 mF/cm2, while the values for aniline monomer and aniline trimer substituted viologens were 0.82 and 2.17 mF/cm2, respectively. The electrochemical stability for 1000 cycles was 98.6%, 90.8%, and 20.3% for the aniline monomer, aniline dimer, and aniline trimer substituted viologens, respectively. Electrolytes with aniline dimer substituted viologen represented good performance and high stability. On the other hand, aniline monomer exhibited poor performance for the supercapacitor, and aniline trimer substituted viologen showed very low stability, originating from a low solubility to build electrolytes. From these results, the aniline dimer was the appropriate substituent for the viologen, and the proposed material is expected to play an important role in enhancing the performance of the organic supercapacitor.

Poly (Ethyl Methacrylate) (PEMA) and its Composites for Various Applications: Background, Recent Progress, and Future challenges

AbstractThis overview looks critically at the present prospects and future challenges in development of polyethyl methacrylate (PEMA) and its composites. It is shown herein to be a promising candidate for various applications, including energy storage, textile, electronics, biomedical, packaging, coatings and adhesives, etc. Due to its high ionic conductivity, thermal stability, and low cost of synthesis, PEMA is also used as a solid electrolyte in supercapacitors. This polymer has the ability to transport ions efficiently between the two electrodes of the supercapacitor, thereby leading to improved performance and efficiency. Additionally, PEMA can withstand high temperatures without breaking down, thus making it suitable for a range of applications. Further, it is shown due to its unique properties and versatility, PEMA has significant potential for a range of biomedical applications. This review of existing literature strongly suggests that the use of PEMA as a solid electrolyte in supercapacitors can be of significant potential for advancing energy storage technology. It also warrants further research to optimize its use in many other challenging practical applications.

Development and Characterization of Highly Ionic Conductive Hydrogel Electrolytes for Supercapacitors

Development and Characterization of Highly Ionic Conductive Hydrogel Electrolytes for Supercapacitors

Corn Starch-Sodium Acetat Composite Material from Industrial Waste Fly Ash for Solid Electrolyte Polymer Ionic Conductivity in Supercapacitor Application

Solid polymer electrolyte (SPE) is a safer alternative to use than liquid electrolytes. This research focuses on the highest conductivity with fly ash filler in solid polymer electrolyte (SPE) based on corn starch, using the solution casting method. The crystallinity and interaction between fly ash and Na+ ions of solid polymer electrolyte were seen by X-ray Diffraction (XRD), then Fourier Transform Infra-Red (FTIR), showing a shift in functional groups due to the interaction of SiO2 in fly ash and Na+ ions, and surface morphology forms was observed by Scanning Electron Microscopy (SEM). Ionic conductivity was analyzed by Electrochemical impedance Spectrometry (EIS). solid polymer electrolyte with fly ash showed the highest ionic conductivity 2,51 x 10-4 S/cm, at room temperature with addition fly ash 10%. the highest conductivity result was corresponding with amorphous peak with same concetration on XRD. SPE based on corn starch with Fly ash filler has potential to be used as a solid polymer electrolyte in supercapacitors.