Nature Of Electrolyte Research Articles

Building a highly functional Li1.3Al0.3Ti1.7(PO4)3/poly (vinylidene fluoride) composite electrolyte for all-solid-state lithium batteries

Solid-state electrolytes have become a promising approach for rechargeable lithium batteries with enhanced safety and high energy density. However, the rigid nature of ceramic electrolytes would result in the poor interfacial contact, and polymer electrolytes suffer from inferior electrochemical performance and unsatisfied mechanical strength to suppress Li dendrites. In this work, we report a flexible Li1.3Al0.3Ti1.7(PO4)3 (LATP)-reinforced polyvinylidene fluoride (PVDF)-based solid composite electrolyte with superior performances in terms of high ionic conductivity (1.64 × 10−3 S cm−1 at room temperature), high lithium transference number (0.45), wide electrochemical window (0–4.76 V) and enhanced tensile strength (14.2 MPa). The existence of LATP permits the utilization of high Li-salt content which increases the charge carrier concentration. Meanwhile, LATP facilitates the Li+ conduction process and enhances the mechanical strength, leading to a long-term electrochemical stability of symmetric Li cell for 600 h at 0.2 mA cm−2. Assembled with LiFePO4 cathode, the all-solid-state Li battery delivers a high capacity of 153.7 mA h g−1 at 0.3 C with remarkable cycle stability. This work provides a bright future for composite polymer electrolytes in the application of all-solid-state lithium batteries.

Environment-Friendly Design of Lithium Batteries Starting from Biopolymer-Based Electrolyte

The nondegradable nature and toxicity of organic liquid electrolytes reveal the design deficiency of lithium batteries in environmental protection. Biopolymers can be extracted from biomass under mild conditions, thus they are usually low cost and renewable. The unique characteristics of biopolymers such as water solubility, film-forming capability and adhesive property are of importance for lithium battery. The studies on the biopolymer materials for lithium batteries have been reviewed in this work. Although a lot of work on the biopolymer-based battery materials has been reported, it is still a challenge in the design of lithium battery with zero pollution and zero waste.

Effect of different dosage of gamma irradiation on quasi-solid-state conducting polymer electrolyte and its application as high performance dye-sensitized solar cells

ABSTRACT The nanocomposite polymer electrolyte [x (85 PVA: 10 PPy: 5 KI: I2:15 EC: 15MPII: 10 TiO2) for x = 5, 10, 15 Gy γ-ray irradiation] is prepared using the solution casting technique. Exposure of γ-ray irradiation enhanced the amorphous nature of the polymer electrolyte, is confirmed by XRD. The 15Gy γ-ray-irradiated nanocomposite polymer electrolyte has higher electrical conductivity and minimum activation energy (0.664 kJ mol−1). The EIS measurement reveals that the 15Gy γ-ray-irradiated nanocomposite polymer electrolyte incorporated DSSC shows lower Rct 1 and Rct 2 values at the counter electrode/electrolyte and photoanode/electrolyte interface, respectively. An outstanding performance is observed in the fabricated DSSCs using 15 Gy γ-ray-irradiated nanocomposite polymer electrolyte with a short circuit current density of 12.602 mA cm−2, an open-circuit voltage of 0.711 V, a fill factor of 0.535, and a photovoltaic conversion efficiency of 4.79% under the light intensity of 100 mW cm−2.

Towards High‐Performance Zinc‐Based Hybrid Supercapacitors via Macropores‐Based Charge Storage in Organic Electrolytes

AbstractZn‐based aqueous supercapacitors are attracting extensive attention. However, most of the reported long‐life and high‐power performances are achieved with low Zn‐utilization (<0.6 %) and low mass loading in cathode (<2 mg cm−2). And, many obtained high energy densities are generally evaluated without considering the mass of Zn‐anode. Herein, we propose a Zn‐based hybrid supercapacitor, involving a metal organic framework derived porous carbon cathode, a Zn‐anode and an N, N‐dimethylformamide (DMF)‐based electrolyte containing Zn2+. We demonstrate that the charge storage of cathode mainly occurs in macropores, showing high rate performance at high mass loading (40 mg cm−2). Furthermore, the aprotic nature of electrolyte and formation of Zn2+‐DMF complex avoid the Zn‐corrosion and dendrite formation. Therefore, the supercapacitor shows a long‐life (9,000 cycles) with a high Zn‐utilization (2.2 %). When calculated with the total mass of cathode (40 mg cm−2) and Zn‐anode, the energy density reaches 25.9 Wh kg−1.

Promising biodegradable polymer blend electrolytes based on cornstarch:PVP for electrochemical cell applications

Higher proton conducting polymer blend electrolytes (HPCPBEs) of cornstarch:poly vinyl pyrrolidone (PVP):ammonium thiocyanate (NH4SCN) have been prepared by solution casting technique. Enhancement of amorphous nature of the polymer blend electrolytes have confirmed by X-ray diffraction analysis. The presence of functional groups in Fourier transform infrared spectrum shows the complexation between salt and host polymer matrix. At ambient temperature, 70 wt% NH4SCN mixed composition has obtained the maximum conductivity (1.36 × 10–4 S cm–1). The dielectric properties of the prepared samples have been analysed. The dielectric spectra and modulus spectra reveal the non-Debye behaviour of the polymer electrolytes. Low activation energy (0.14 eV) with regression value of 0.98 has been revealed from temperature dependence of ionic conductivity studies. Wagner’s polarization technique is used to confirm the conductivity due to the ions. Electrochemical behaviour of HPCPBE has been analysed by cyclic voltammetry. An electrochemical cell has fabricated using the HPCPBE and the observed open circuit voltage is 1.15 V.

Characterization of solid biopolymer electrolytes based on kappa-carrageenan with Magnesium nitrate hexahydrate and its application to electrochemical devices

ABSTRACT Biopolymers have been widely investigated due to their environmental friendly nature. Kappa carrageenan is one of a biopolymer with strong stability, good film-forming tendency, and soluble in hot water. In this work, solid Magnesium biopolymer electrolytes has been developed using Kappa carrageenan with various molecular weight percentage (Mwt%) of Magnesium nitrate as salt, by solution casting technique using distilled water as a solvent. Structural, thermal, electrical, and electrochemical behavior of developed membrane are investigated using various techniques such as XRD, DSC, AC impedance, LSV, and transference number measurement. XRD confirms the amorphous nature of the polymer electrolyte. The biopolymer electrolyte of 1g Kappa carrageenan: 0.5 Mwt% of Magnesium nitrate Mg(NO3)2.6H2O has got maximum magnesium ion conductivity of 7.05 × 10−4 S cm−1.This membrane has got highest amorphous nature. The ionic connectivity has been improved to one order of magnitude due to the inclusion of 0.5 Mwt% of Ethylene carbonate plasticizer with the highest connecting biopolymer electrolyte 1 g K-Carrageenan: 0.5 Mwt% of Mg(No3)2.6H2O.Glass transition temperature of the prepared membrane has been measured by DSC technique. LSV technique is used to measure the electrochemical stability of the highest conducting biopolymer electrolytes. Primary magnesium battery is fabricated using maximum ionic conductivity biopolymer electrolyte (1 g K-Carrageenan: 0.5 Mwt% of Mg(NO3)2.6H2O and 1 g K-Carrageenan: 0.5 Mwt% of Mg(NO3)2.6H2O:0.5Mwt% of EC). The fabricated primary magnesium battery exhibits open circuit voltage of 1.8 V and 1.97 V have been observed for the 1 g K-C:0.5 mwt% of Mg(No3)2.6H2O and 1 g K-C:0.5 Mwt% of Mg(No3)2.6H2O:EC, respectively, and its performance is studied.

Towards High-Performance Zinc-Based Hybrid Supercapacitors via Macropores-Based Charge Storage in Organic Electrolytes.

Zn-based aqueous supercapacitors are attracting extensive attention. However, most of the reported long-life and high-power performances are achieved with low Zn-utilization (<0.6 %) and low mass loading in cathode (<2 mg cm-2 ). And, many obtained high energy densities are generally evaluated without considering the mass of Zn-anode. Herein, we propose a Zn-based hybrid supercapacitor, involving a metal organic framework derived porous carbon cathode, a Zn-anode and an N, N-dimethylformamide (DMF)-based electrolyte containing Zn2+ . We demonstrate that the charge storage of cathode mainly occurs in macropores, showing high rate performance at high mass loading (40 mg cm-2 ). Furthermore, the aprotic nature of electrolyte and formation of Zn2+ -DMF complex avoid the Zn-corrosion and dendrite formation. Therefore, the supercapacitor shows a long-life (9,000 cycles) with a high Zn-utilization (2.2 %). When calculated with the total mass of cathode (40 mg cm-2 ) and Zn-anode, the energy density reaches 25.9 Wh kg-1 .

Oxovanadium(IV) Complexes with Triazole Based Schiff Base Ligands: Synthesis, Characterization and Antibacterial Study

Schiff bases have been synthesized by the reaction of triazole containing primary amine with aromatic carbonyl compounds. The Schiff bases prepared, act as ligand when these are made in contact with oxovanadium (VO2+) ion. Some new mononuclear oxovanadium(IV) complexes have been synthesized by the reaction of Schiff base ligands with vanadyl sulphate (VOSO4.xH2O) and the complexes are analyzed by different spectroscopic methods; [fourier-transform infrared (FTIR), ultraviolet-visible (UV-Vis.), electron paramagnetic resonance (EPR)], X-ray diffraction (XRD) analysis, elemental analysis, and conductivity measurement. The complexes have been well characterized based on analytical data. The electrolytic nature of the complexes was determined based on the molar conductance values. The powder XRD pattern has been used to determine crystal size and type. The synthesized Schiff base ligands and oxovanadium(IV) complexes were found to be stable in air and moisture at room temperature. On the basis of the physicochemical data, the tentative geometry of the complexes has been proposed. Antibacterial sensitivity of the ligand and its metal complexes have been assayed in vitro against bacterial pathogens viz. growth inhibitory activity of ligands and complexes against pathogens has also been determined.

Flexible and self-healable poly (N, N-dimethylacrylamide) hydrogels for supercapacitor prototype

Flexible, and self-healable supercapacitors possess significant advantages over liquid electrolyte based supercapacitors. Liquid electrolytes are usually organic and not environmentally friendly. Therefore, flexible water-based electrolyte is a reliable choice. Water-based hydrogel electrolyte is a novel approach to overcome liquid electrolyte related drawbacks. In this study, we propose physically crosslinked poly (N, N-dimethylacrylamide) hydrogel using sodium montmorillonite as a crosslinking agent. The hydrogel electrolytes are prepared by adding different weight % (wt.%) of magnesium trifluoromethanesulfonate (MgOTf) salt as a source of ions. The synthesized hydrogel and hydrogel electrolytes are characterized via functional group identification, thermal decomposition, surface morphology, and elemental composition. Fourier transform infrared (FTIR) deconvolution and transference number measurement are conducted to confirm the complexation and ionic species. Based on the surface morphology, FTIR, and transference number measurement, it could be deduced that enhanced ionic conductivity is due to the amorphous nature of hydrogel electrolyte. Furthermore, an ionic conductivity study revealed that hydrogel electrolyte formulated by adding 30 wt.% salt (DMA3) attained maximum ionic conductivity of 6.69 × 10−3 S/cm. The electrochemical characterization of fabricated symmetric supercapacitor described that AC/DMA3/AC achieved the highest specific capacitance of 119 F/g at 3 mV/s and 142 F/g at 50 mA/g along with 98.07 % capacitance retention at 4 A/g after 5000 consecutive charge-discharge cycles. In addition, a flexible prototype supercapacitor device was designed using two symmetrical optimized AC/DMA3/AC cells connected in series, charged with external power supply, and lighted up the light-emitting diode (LED). The self-healability of the prototype was also examined. Results are very promising for the development of compact, self-standing, self-healable, highly flexible, lightweight, and biocompatible supercapacitors.

Synthesis, characterization, biological and electrochemical investigation of copper (II) complexes containing 4-chloro-2-[2, 6-diisopropylphenylimino) methyl] phenol Schiff base ligand and aromatic diinines

Abstract Herein we reported the synthesis of Schiff base ligand and their complexes (1–5) with copper (II) metal ion and aromatic diimines. The Schiff base derived from the condensation of 2, 6- diisopropylaniline and 5- chlorosalicylaldehyde.The Schiff base ligand and their complexes (1–5) have been characterized by microanalysis, molar conductance, room temperature magnetic susceptibility, FT – IR, UV–visible, Cyclic voltammetry and mass spectroscopy techniques. Their low electrical conductance values indicate that the complex 1 is non electrolyte and remaining other complexes 2-5 are in electrolyte nature. The monomeric nature of the complexes is evidenced from their magnetic susceptibility values. The electronic spectra of the complexes suggest that they have distorted octahedral geometry around the metal ion. The electrochemical behavior, the anodic and cathodic peak potential and the number of electron transfer have been calculated by using cyclic voltammetry. These synthesized complexes have been tested against micro-organisms such as S. aureus, B. bacillus (Gram – positive) and E. coli, P. aeruginosa (Gram – negative) bacterial strains with known antibacterial and antifungal drugs (amoxyclav and oxiconazole).

Crystal structure, spectroscopic, DFT calculations and antimicrobial study of the Cu(II) complex bearing second-generation quinolone ofloxacin and 2,2′-bipyridine

Cu(II) complex of second-generation quinolone ofloxacin with 2,2′-bipyridine formulated as [Cu(ofx)(2bpy)(H2O)].ClO4·2H2O (1) [ofx = ofloxacin, 2bpy = 2,2′-bipyridine] has been synthesized. The coordination possibility of the ofx and 2bpy towards metal ion was proposed using single-crystal X-ray diffraction analysis (SCXRD), IR, UV–Visible, EPR, thermal analysis, molar conductance, and elemental analysis. The interaction of Cu(II) with the deprotonated ofloxacin ligand resulted in the formation of the mononuclear complex of the type [Cu(ofx)(2bpy)(H2O)].ClO4·2H2O. Single crystal X-ray crystallography data revealed a five-coordinate, distorted square-pyramidal arrangement in the complex. The complex crystallizes in the triclinic system with a = 10.2192(13), b = 12.7080(19), c = 12.8156(16) Å, and space group P–1. The measurement of the complex molar conductance in DMSO (10−3 M solution at 25 °C) revealed the electrolytic nature of the complex and was of the 1:1 type. The presence of coordinated water molecules and the metal oxide in the final product was determined by thermal analysis studies. DFT calculations were carried out for the complex ion and the two ligands using the B3LYP/631-G(d) level of theory and the HOMO-LUMO energy gap was evaluated. The results showed that the complex with the lowest energy gap value (0.951 eV) is more reactive than the ligands. The ligand and its copper (II) complex were screened in order to evaluate the antimicrobial activity by measuring the inhibition zone (mm). The results showed that the metal complex was observed to be more active than the parent ligand.

Electrochemical Performance of Mg Metal‐Quinone Battery in Chloride‐Free Electrolyte

AbstractMg batteries are a promising energy storage system due to the high capacity of the Mg metal anode. However, until recently Mg battery practical application seemed very distant due to corrosive nature of Mg electrolytes and the lack of suitable cathode materials. In this work, we bridge this gap by combining novel chloride‐free Mg electrolyte, Mg perfluorinated pinacolato borate (MgFPB), with quinone based organic cathode. ATR‐IR spectroscopy and complementary energy dispersive X‐ray spectroscopy (EDS) of ex situ cathodes confirm reduction of carbonyl group during discharge an its preferred coordination with Mg2+ cations, although monovalent not fully dissociated MgFPB+cation pairs are detected as well. Mediocre capacity retention of PAQS/CNTs is improved through the use of phenanthrenequinone based polymer (PFQ/rGO). The study demonstrates the promising performance of organic compounds in chloride‐free electrolytes and points towards future steps on the path towards practical Mg metal organic batteries.

Au and Pt Diffusion in Electrodeposited Amorphous Sb2Te3 Thin Films

Amorphous Sb2Te3 thin films are synthesized using electrodeposition in different thicknesses to explore their solid electrolytic nature with respect to some noble metals. Au and Pt are used as the substrate materials and thermally diffused into the Sb2Te3 films under passivated and nonpassivated conditions. Rutherford backscattering spectrometry is used to study the Au and Pt diffusion into the films as a function of depth. It is found that Au diffuses into the Sb2Te3 thin films even at room temperature. In contrast, there is no observable diffusion of Pt at room temperature. At a higher temperature (i.e., 200 °C), both Au and Pt diffuse into the Sb2Te3 thin films and Au diffusion is more significant than Pt. The findings suggest that amorphous Sb2Te3 can be used as a good solid electrolyte to permit the diffusion of some noble metals such as Au and Pt.

Ionic liquid incorporated polyvinylpyrrolidone (PVP) doped with ammonium iodide (NH4I) doped solid polymer electrolyte for energy device

In this work, we have used solution cast technique method to Synthesize an ionic liquid incorporated PVP with ammonium iodide doped solid polymer electrolyte. There was an inclination of one order conductivity in PVP-NH4I complex after addition of ionic liquid in it which was justified by complex impedance spectroscopy. Fourier transform infrared spectroscopy and Polarized optical microscopy was also done to check the blending nature and amorphousity of the polymer electrolyte. At last, we have successfully developed a supercapacitor using IL doped polymer electrolyte shows a reasonable and stable efficiency.

Reduction of Formate Crossover in Sequential-Flow Microfluidic Fuel Cells

Microfluidic fuel cells (MFCs) exploit the colaminar nature of aqueous electrolytes to separate the pair of electrodes, garnering tremendous interest as micro-power devices. However, fuel crossover...

Ionic liquid impregnated Allium cepa peel for supercapacitor application

This paper report a new biodegradable epidermis of onion (Allium cepa) doped with low viscosity ionic liquid as novel electrolyte for EDLC application. The porous membrane used in present study was epidermis of onion (onion peel membrane) and low viscosity ionic liquid (IL) i.e. 1-ethyl 3-methyl imidazolium thiocynate. The electrical, structural, optical characterization was carried out in detail. The optical micrographs show addition in amorphosity with adding IL. Fourier transform infrared spectroscopy (FTIR) revealed the interaction between ionic liquid and membrane as well as composite nature of membrane electrolyte. Impedance spectroscopy revealed the twofold enhancement in conductivity value by doping IL. Electrical double layer supercapacitor (EDLC) has been fabricated using carbon nanotube (CNT). Cyclic voltammetry and low frequency impedance spectroscopy data further affirm the reasonable value of specific capacitance (Csp = 9.2F/g).

Synthesis, characterization and antimicrobial activities of heteroleptic metal chelates of isoniazid and 2,2’-bipyridine

The Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes of isoniazid (L1) mixed with 2,2-bipyridine (L2) were synthesized and characterized by solubility studies, percentage metal analysis, UV-Vis spectroscopy, IR spectroscopy, conductivity measurements and magnetic moment measurements. The IR spectra revealed that the isoniazid coordinated as a bidentate ligand. In Co(II) and Ni(II) complex it coordinated via the carbonyl oxygen (C=O) and the amide nitrogen, while in the Cu(II), Mn(II) and Zn(II) complexes it coordinated using the amide and carbonyl oxygen via enolization. Bipyridine also bonded to the metals as a bidentate ligand through the pyridinic nitrogen atoms. The magnetic data showed that all the complexes were paramagnetic with values ranging from 1.70 to 5.0 B.M., except [Zn(Is)(Bipy)(H2O)Cl2] which was diamagnetic. The conductivity results revealed that the Cu(II), Mn(II), Zn(II) complexes were 1:1 electrolytes while Co(II) was 1:2 electrolyte and [Ni(Is)(Bipy)Cl2] was non-electrolytic in nature. The antibacterial activities of the ligands and the complexes as evaluated via the agar diffusion method showed that the complexes displayed moderately high antimicrobial activity in comparison with the free ligands when tested against ten strains of bacteria.&#x0D; &#x0D; KEY WORDS: Isoniazid, Electronic structure, Geometry, Antimicrobial activity, Electrolytic nature, Magnetic moment&#x0D; &#x0D; Bull. Chem. Soc. Ethiop. 2020, 34(3), 471-478.&#x0D; DOI: https://dx.doi.org/10.4314/bcse.v34i3.4

Bioactive Metal Complexes of Schiff Base Derived from 2,3-Dioxobutane, Ethane-1,2-diamine and 4-Chloro-2-formylphenol: Spectral Studies and in vitro Antimicrobial Activity

A novel series of trivalent coordination complexes was synthesized by the reaction between a chloride/ acetate salt of iron, chromium, cobalt or manganese ions and NNNNOO type persuasive Schiff base ligand synthesized from 2,3-dioxobutane, ethane-1,2-diamine and 4-chloro-2-formylphenol. Synthesized compounds were characterized by using elemental analysis, molar conductance, magnetic moment, IR, UV-visible, 1H NMR, 13C NMR and ESI-MS spectral analyses. IR and NMR spectra favoured hexadentate coordination behaviour of ligand. Electronic spectra and magnetic moment data reveal Oh geometry with distortion around the metal ion in complexes. The molar conductance values show 1:1 electrolytic nature of complexes. Biological potentiality of the ligand and its metal complexes were tested in vitro against two bacterial and two fungal strains; Bacillus subtilis, Escherichia coli and Aspirgillus niger, Aspirgillus flavus, respectively.

A high energy and power all-solid-state lithium battery enabled by modified sulfide electrolyte film

In recent decades, all-solid-state lithium batteries have gained enormous attention due to the improved safety performance and high specific energy. However, the brittle nature of sulfide-based solid electrolytes and poor interface compatibility limit the long-cycle stability and high rate performance of ASSLBs. The utilization of a thick solid electrolyte further reduces the cell-level energy and power. Herein, we prepare a thin sulfide electrolyte film (65 μm) using modified Li6PS5Cl and poly (ethylene oxide) (PEO). Under a high loading of 4.46 mA h cm−2, the assembled cell employing this electrolyte film with LiNi0.7Co0.2Mn0.1O2 cathode and lithium-indium alloy anode maintains a 1000 stable cycles with 74% capacity retention and average 99.85% coulombic efficiency at 60 °C. The cell-level energy and power are increased by an order of magnitude compared with traditionally prepared solid-state batteries. An excellent specific power of 374.7 W kg−1 is delivered at the initial cycle. This modified electrolyte film is expected to be commercially produced in the near future.

A Viologen-Based Anolyte with a Very Negative Redox Potential for Neutral Aqueous Redox Flow Batteries

Redox flow batteries have been recognized as a promising option for energy-storage purposes, mitigating the intermittency of renewable sources of energy such as solar, wind, and hydroelectric power. In particular, aqueous redox flow batteries (ARFBs) are very attractive owing to high conductivity, relatively low cost, and safe nature of aqueous electrolytes. Performance of ARFBs can be further improved with developing new electroactive species. Viologens are a group of organic compounds with great tunability, making them appealing for flow battery applications. In this study, a viologen-based electroactive compound called MMV is proposed with the potential of improving performance of aqueous flow batteries.The potential of MMV as an anolyte was investigated for developing a neutral aqueous flow battery. MMV required a simple synthesis procedure with inexpensive starting materials, resulting in a low cost. MMV showed solubility of almost 3 M that is relatively high compared to other organic electroactive compounds, such as quinones, especially in neutral electrolytes. The electrochemical reaction of MMV involved the transfer of one electron at fast kinetics. Additionally, MMV demonstrated a redox potential of -1.05 V vs. SCE that is one of the most negative redox potentials reported for organic electroactive species under neutral conditions. These characteristics indicated that MMV is a promising anolyte candidate. Such a very negative redox potential and high solubility provide MMV the potential to significantly improve performance of a flow battery in terms of capacity, energy density, and cell potential. Despite these interesting properties, MMV exhibited a poor cycling performance. MMV underwent irreversible reactions at elevated concentrations. Signs of dimerization and also precipitation were observed during cycling. The irreversible reactions led to a high capacity fade rate (2.1%/cycle). Approaches to improve the cycling performance include synthesizing MMV-derivatives that possess a higher charge compared to that of MMV to possibly limit the extent of both dimerization and precipitation.