Quasi-solid State Electrolyte Research Articles

Characterization of poly (vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) nanofiber membrane based quasi solid electrolytes and their application in a dye sensitized solar cell

The electrolyte plays a major role in dye sensitized solar cells (DSSCs). In this work a quasi-solid state (gel) electrolyte has been formed by incorporating a liquid electrolyte made with KI dissolved in ethylene carbonate (EC) and propylene carbonate (PC) co-solvent in poly (vinylidene fluoride-hexafluoropropylene) (PVdF-HFP) co-polymer nanofiber membrane prepared by electrospinning. SEM images of the electrolyte membrane showed the formation of a three-dimensional network of polymer nanofibers with diameters between 100 and 300 nm and an average membrane thickness of 14 μm. The electrolyte was characterized by FTIR and differential scanning calorimetry (DSC) measurements. The DSSCs fabricated with this electrolyte were characterized by current-voltage and Electrochemical Impedance Spectroscopy (EIS) measurements. DSC thermograms revealed that the crystallinity of the PVdF-HFP nanofiber is 14% lower than that of the pure PVdF-HFP polymer while the FTIR spectra showed a reduced polymer-polymer interaction in the nano fiber based gel electrolyte. The DSSCs fabricated with nanofiber based gel electrolyte showed an energy conversion efficiency of 5.36% under 1.5 a.m. solar irradiation, whereas the efficiency of the DSSC made with the liquid electrolyte based cell was 6.01%. This shows the possibility of replacing the liquid electrolyte in DSSCs by electro-spun polymer nanofiber based gel electrolyte and thereby minimizing some major drawbacks associated with liquid electrolyte based solar cells while maintaining a reasonably high efficiency.

A study nanocrystalline TiO2 based on dye sensitized solar cells with quasi solid state electrolytes

A quasi solid state electrolytes can be done by adding potassium iodide (KI) and iodine (I2) into quasi solid state electrolytes. Consisting 1,2,4,5–tetrakisbromomethyl benzene (TB), γ –butyrolactone (GBL), propylene carbonate (PC), and ethylene carbonate (EC) gelated with sample 1, 2, 3 and 4. Potassium iodide salt poorly soluble in liquid electrolyte, but can dissolve completely in quasi solid state electrolytes. The dye sensitized solar cell (DSSCs) with the quasi solid state electrolytes were fabricated. The results showed that the energy conversion efficiency of light to electricity were 0.052%, 0.126%, 0.121% and 0.125%., respectively, under irradiation of 80 mW/cm2. The performance of the dye sensitized solar cell with quasi solid state electrolytes is more stable than that of liquid electrolytes.

Ionic liquid/ether-plasticized quasi-solid-state electrolytes for long-life lithium–oxygen cells

Li–O2 cells with quasi-solid state electrolytes plasticized by an ionic liquid/ether exhibit a long cycle life.

Use of fumed silica nanoparticles to attain polymer free novel quasi-solid state electrolyte for high-efficiency dye-sensitized solar cells

Novel gel electrolyte is prepared by replacing conventional polymers solely by fumed silica nanoparticles. In the gel composition, ethylene carbonate and propylene carbonate are used as solvents with the tetrapropylammonium iodide/iodine redox couple. The molar ratio of total oxygen moles of ethylene carbonate and propylene carbonate to iodide moles of tetrapropylammonium iodide (O:I−) is varied from 80:1 to 40:1 and the best room temperature ionic conductivity of 6.90×10−3 S cm−1 is achieved for the system with the molar ratio at 50:1. The dye-sensitized solar cell (DSC) employing this gel electrolyte gives a light-to-electricity conversion efficiency of 7.46% under irradiation of 100 mW cm−2. The electrolyte and the fabricated DSCs are characterized using linear sweep voltammetry, FT-IR spectroscopy, current-voltage characteristics and photocurrent action spectra.

Natural pigment sensitized solar cells based on ZnO-TiO2-Fe2O3 nanocomposite in quasi-solid state electrolyte system

Nanocomposites of Zn-Ti-Fe oxide using zinc as a host with different ratios of precursor salts were prepared by co-precipitation method to use as semiconductors for dye sensitized solar cell (DSSC). The as-synthesized nanocomposites were characterized using XRD, SEM-EDX, TEM and UV-Vis spectrophotometer. DSSCs based on the new semiconductors and di-tetrabutylammoniumcis-bis(isothiocyanato)bis(2,2’-bipyridyl-4,4’-dicarboxylato)-ruthenium(II) (N719) dye has been constructed and characterized. Stability towards dissolution of deposited films of semiconductors in the acidic dye and conversion efficiency was obtained in the order of: ZnO(100%) <ZnO(70%)-TiO2(30%) <ZnO(70%)-Fe2O3(30%) <ZnO(60%)-TiO2(20%)-Fe2O3(20%). Natural pigments were also extracted using ethanol and water as solvents from flowers of Guizotia scabra and Salvia leucantha plants. From UV-Vis spectra analysis all ethanol extracts of natural sensitizers absorb in the visible region. DSSCs were constructed using the natural pigments as sensitizers. The following best device parameter was achieved by the ethanol extract of Salvia leucantha and ZnO-TiO2-Fe2O3 nanocomposite semiconductor. When the potential is scanned: a Voc of 280 mV, Jsc of 0.01761 mAcm-2 at light intensity of 100 mWcm-2 were obtained; the maximum IPCE % was 1.7 and 25.7 for the N719 dye and Salvia luecantha, respectively. KEY WORDS: Nanocomposite, Co-precipitation method, Semiconductor, Dye sensitized solar cell, Natural pigments, Conversion efficiency Bull. Chem. Soc. Ethiop. 2017, 31(2), 263-279. DOI: http://dx.doi.org/10.4314/bcse.v31i2.8

Quasi-solid state dye-sensitized solar cells based on I−/I3− ions

The leakage of liquid electrolytes is crucial for the application of dye-sensitized solar cells (DSCs). The ion transport in solid imidazolium iodides used as the quasi-solid state electrolyte (EL) of DSCs was investigated. The imidazolium EL, whose melting point is ca. 100 °C, was chosen to fully penetrate in porous TiO2 by the heat permeation method. The apparent diffusion coefficients (D) of I3− in porous TiO2 are on the order of 1,3-dimethly-imidazolium (DM+) > 1-ethyl-3-methylimidazolium > 1,2-dimethyl-3-propylimidazolium > 1-butyl-2,3-dimethylimidazolium. D increases with decreasing imidazolium cation size. Therefore, the effective distance between I− and I3− was assumed to decrease with decreasing cation size. The transport-limited current of DM+ at the TiO2 thickness of 20 µm is ca. 30 mA·cm−2. The result suggests that the I3− transport in DM+ can compensate for the large short circuit current (30 mA·cm−2).

Quasi solid-state electrolytes based on ionic liquid (IL) and ordered mesoporous matrix MCM-41 for supercapacitor application

Quasi solid-state electrolytes (QS-SEs) based on an ionic liquid ([EMIM][FSI]) immobilized in ordered mesoporous silica MCM-41 using physical imbibition process have been developed. Supercapacitor assembly obtained using activated carbon electrodes and QS-SEs can be operated up to 2 V and exhibit good specific capacitance of 30 F g−1. The specific energy and power densities of the supercapacitor are found ~17 Wh kg−1 and 1000 W kg−1, respectively, at 1 mA cm−2 current density and exhibit good cycle performance at room temperature.

Quasi-solid state electrolyte for semi-transparent bifacial dye-sensitized solar cell with over 10% power conversion efficiency

In traditional dye-sensitized solar cells (DSSCs), the liquid electrolyte (LE) presents a problem for long-term stability. Herein, we demonstrate a bifacial DSSC by combining a new metal-free organic dye and a quasi-solid state electrolyte (QSSE) that contains poly(vinylidenefluoride-co-hexafluoropropylene) (PVdF-HFP)-based polymer gel. The incident light irradiates the front side of the DSSC, and the transmitted light is reused after reflection on the back side. Owing to the semi-transparent DSSC electrode, the reflected light can penetrate and be absorbed by the dye molecules in the DSSC, thereby enhancing the short-circuit current density and thus the overall power conversion efficiency (PCE). The PCE for the DSSC device with QSSE from bifacial irradiation is 10.37%, a value that is comparable to that obtained with LE-based DSSC (9.89%). The stability of the device is enhanced when the polymer gel containing PVdF-HFP is mixed with the LE, and the effectiveness of PVdF-HFP as a gelator is attributed to its interaction with the Li+ ions. Based on our preliminary results, this architecture can lead to more stable bifacial QSSE-based DSSCs without sacrificing the photovoltaic performance.

Application of electrospun cellulose acetate nanofibre membrane based quasi-solid state electrolyte for dye sensitized solar cells

Dye Sensitized Solar Cells (DSSCs) are much more eco-friendly, low cost and easy to fabricate devices compared to silicon solar cells. In order to overcome their problems with safety and the long-term stability due to sealing problems, liquid electrolytes employed in these devices are replaced with quasi solid-state or gel electrolytes even though the overall efficiencies are somewhat lower. In this study DSSCs are fabricated and tested by replacing the conventional liquid electrolyte using a quasi–solid state electrolyte comprised of biodegradable electro spun cellulose acetate (CA) nanofibres. DSSCs fabricated with this quasi-solid state electrolytes showed an overall light to electricity conversion efficiency of 4.0% under the illumination of 100 mW cm-2 (AM 1.5). The corresponding values of short circuit current density (Jsc), open circuit voltage (Voc) and the fill factor (FF) of this device were 9.83mA cm-2, 699.1 mV and 0.58 respectively.

A low cost composite quasi-solid electrolyte of LATP, TEGDME, and LiTFSI for rechargeable lithium batteries**Project supported by the National Natural Science Foundation of China (Grant Nos. 52315206 and 51502334), the Funds from the Ministry of Science and Technology of China (Grant No. 2016YFB0100100), the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No. XDA09010000), and the Foundation

The composite quasi solid state electrolytes (CQSE) is firstly synthesized with quasi solid state electrolytes (QSE) and lithium-ion-conducting material Li1.4Al0.4Ti1.6(PO4)3 (LATP), and the QSE consists of [LiG4][TFSI] with fumed silica nanoparticles. Compared with LATP, CQSE greatly improves the interface conductance of solid electrolytes. In addition,it has lower liquid volume relative to QSE. Although the liquid volume fraction of CQSE is droped to 60%, its conductivity can also reach 1.39×10−4 S/cm at 20 °C. Linear sweep voltammetry (LSV) is conducted on each composite electrolyte. The results show the possibility that CQSE has superior electrochemical stability up to 5.0 V versus Li/Li+1. TG curves also show that composite electrolytes have higher thermal stability. In addition, the performance of Li/QSE/LiMn2O4 and Li/CQSE/LiMn2O4 batteries is evaluated and shows good electrochemical characteristics at 60 °C.

Bio-based chitosan/PVdF-HFP polymer-blend for quasi-solid state electrolyte dye-sensitized solar cells

AbstractDye-sensitized solar cells (DSSCs) have emerged to become one of the most promising alternatives to conventional solar cells. However, long-term stability and light-to-energy conversion efficiency of the electrolyte in DSSCs are the main challenges in the commercial use of DSSCs. Current liquid electrolytes in DSSCs allow achieving high power conversion efficiency, but they still suffer from many disadvantages such as solvent leakage, corrosion and high volatility. Quasi-solid state electrolytes have therefore been developed in order to curb these problems. A novel polymer electrolyte composed of biobased polymer chitosan, poly(vinylidene fluoride-hexafluoropropylene) (PVdF-HFP), 1-methyl-3-propylimidazolium iodide ionic liquid and iodide/tri-iodide redox salts in various compositions is proposed in this study as a quasi-solid state electrolyte. Fourier transform infrared microscopy (FTIR) studies on the polymer electrolyte have shown interactions between the redox salt and the polymer blend. The quasi-solid state electrolyte tested in DSSCs with an optimised weight ratio of PVdF-HFP:chitosan (6:1) with ionic liquid electrolyte PMII/KI/I2 has shown the highest power conversion efficiencies of 1.23% with ionic conductivity of 5.367×10−4 S·cm−1 demonstrating the potential of using sustainable bio-based chitosan polymers in DSSCs applications.

High-performance of self-powered UV photodetector with long-term stability based on ZnO nanorods and an iodine-free quasi solid-state electrolyte

Self-powered UV photodetector based on ZnO nanorods and an iodine-free quasi solid-state electrolyte exhibits high photoresponse and great stability.

Dye-sensitized solar cells using natural dye as light-harvesting materials extracted from Acanthus sennii chiovenda flower and Euphorbia cotinifolia leaf

Abstract Natural dyes are environmentally and economically superior to ruthenium-based dyes because they are nontoxic and cheap. In this study, dye-sensitized solar cells (DSSCs) were fabricated using natural dyes light harvesting materials. The natural dyes were extracted from Acanthus sennii chiovenda flower and Euphorbia cotinifolia leaf. In the as-prepared DSSC, a quasi-solid state electrolyte was sandwiched between the working electrode (photoanode) and counter electrode (PEDOT-coated FTO glass). The photoelectrochemical performance of the as-prepared quasi-solid state DSSCs showed open-circuit voltages (V OC ) varied from 0.475 to 0.507 V, the short-circuit current densities (J SC ) ranged from 0.352 to 0.642 mA cm −2 and the fill factors (FF) varied from 47 to 60% at 100 mWcm −2 light intensity. The dye extracted from A. sennii chiovenda flower, using acidified ethanol (in 1% HCl) as extracting solvent, exhibited best conversion efficiency with a maximum open-circuit voltage (V OC ) of 0.507 V, short-circuit current density (J SC ) of 0.491 mA cm −2 , fill factor (FF) of 0.60 and an overall conversion efficiency (η) of 0.15%. On the other hand, the maximum power conversion efficiency of the dye extracted from E. cotinifolia leaf was 0.136%. This is the first study that reports the fabrication of DSSC using natural dye sensitizers extracted from these plants in the presence of quasi-solid state electrolyte and PEDOT as a counter electrode.

Quasi-Solid State Electrolytes for Li-Ion Battery Applications

High energy density secondary batteries are key devices for mobile industrial applications such as electric vehicles, drones and robots. Among attractive new device concepts such as lithium- air, lithium- sulfur, Na/Mg ion and all solid state battery (ASSB), ASSB has been considered to be most promising due to their higher energy density, higher cell output voltage and superior chemical/thermal safety. In this paper, our original approach to electrolyte materials are reported, which are synthesized by hybridization of ionic liquid and nanoparticles. In fact, the quasi-solid state electrolytes have been made by solidification of Li ion conducting ionic liquid by mixing with SiO2 nanoparticles due to strong interaction between ionic liquid molecules and SiO2 surface, which resulted in the electrolytes having liquid-like ionic conductivities in their solid state matrix. All solid state Li battery cell consisting Li metal anode/quasi-solid state electrolytes/LiFePO4 cathode have been successfully fabricated and demonstrated stable charge /discharge cycles more than a thousand under 1.0C-rates in spite of their solid state cell design. More importantly, it has been demonstrated for the first time, bipolar stacked tripled cells with multiple voltages up to 10V are successfully demonstrated on the coin cell CR2032 devices. references [1] Seitaro Ito, Atsushi Unemoto, Hideyuki Ogawa, Takaaki Tomai, and Itaru Honma, J. Power Sources, 2012, 208, 271 [2] Atsushi Unemoto, Hideyuki Ogawa, Seitaro Ito and Itaru Honma, J. Electrochemical Society, 2013, 160, A138 [3] Takaharu MATSUO, Yoshiyuki GAMBE and Itaru HONMA, Scientific Reports,2014,4,6084 [4] Yoshiyuki Gambe, Yan Sun and Itaru Honma, Scientific Reports, 2015, 5, 8869 Figure 1

Absorbency and conductivity of quasi-solid-state polymer electrolytes for dye-sensitized solar cells: A characterization review

Abstract The application of quasi-solid state electrolytes for dye-sensitized solar cells opens up an interesting research field to explore, which is evident from the increasing amount of publications on this topic. Since 2010, significant progress has been made with new and more complicated quasi-solid-states materials being produced. The optimization of new materials requires specific characterizations. This review presents a comprehensive overview and recent progress of characterization methods for studying quasi-solid-state electrolytes. Emphasis is then placed on the absorbency and conductivity characterizations. Each characterization will be reviewed according to the objective, experimental set-up, summary of important outcomes, and a few case studies worth discussing. Finally, strategies for future characterizations and developments are described.

Stable Tin Chloride Perovskite Sensitized Silver Doped Titania Nanosticks Photoanode Solar Cells with Different Hole Transport Materials

Perovskite sensitized solar cells (PSSCs) have recently been catapulted to the cutting edge of thin-film photovoltaic research and development because of their promise for higher power conversion efficiencies and ease of fabrication. In this work, an attempt has been made to fabricate CH3NH3SnCl3 perovskite sensitized silver doped titania nanosticks photoanode solar cells with an efficient hole transport material (HTM), spiro-MeOTAD, poly(3-hexylthiophene-2,5-diyl) (PTTA) and CuI and attained light to electricity power conversion efficiency (PCE) of 10.46, 7.89 and 6.05 % respectively, under AM 1.5G illumination of 100 mW/cm2 intensity. As well, PSSCs made with redox couple electrolytes namely quasi-solid state electrolyte (QSSE) and ionic liquid (IL) electrolyte exhibited the PCE of 4.92 and 3.20 % respectively. A metal oxide (HfO2) layer is coated on the perovskite sensitized photoanode, which could increase the stability of PSSCs. The current density (Jsc)–open circuit voltage (Voc) study shows that PSSCs made with HTMs exhibited better fill factor and PCE. The electron impedance spectroscopy revealed that the electron lifetime (τn), electron mobility (µ) and charge collection efficiency (ηcc)in the PSSCs are in the order spiro-MeOTAD > PTTA > CuI > QSSE > IL. This work expresses that the nature of the HTM is essential for charge recombination and elucidates that finding an optimal HTM for the perovskite solar cell includes controlling the perovskite/HTM interaction.

A Quasi-Solid State DSSC with 10.1% Efficiency through Molecular Design of the Charge-Separation and -Transport.

Organic-based solar cells potentially offer a photovoltaic module with low production costs and low hazard risk of the components. We report organic dye-sensitized solar cells, fabricated with molecular designed indoline dyes in conjunction with highly reactive but robust nitroxide radical molecules as redox mediator in a quasi-solid gel form of the electrolyte. The cells achieve conversion efficiencies of 10.1% at 1 sun, and maintain the output performance even under interior lighting. The indoline dyes, customized by introducing long alkyl chains, specifically interact with the radical mediator to suppress a charge-recombination process at the dye interface. The radical mediator also facilitates the charge-transport with remarkably high electron self-exchange rate even in the quasi-solid state electrolyte to lead to a high fill factor.

A novel quasi-solid state electrolyte with highly effective polysulfide diffusion inhibition for lithium-sulfur batteries

Polymer solid state electrolytes are actively sought for their potential application in energy storage devices, particularly lithium metal rechargeable batteries. Herein, we report a polymer with high concentration salts as a quasi-solid state electrolyte used for lithium-sulfur cells, which shows an ionic conductivity of 1.6 mS cm−1 at room temperature. The cycling performance of Li-S battery with this electrolyte shows a long cycle life (300 cycles) and high coulombic efficiency (>98%), without any consuming additives in the electrolyte. Moreover, it also shows a remarkably decreased self-discharge (only 0.2%) after storage for two weeks at room temperature. The reason can be attributed to that the electrolyte can suppress polysulfide anions diffusion, due to the high ratio oxygen atoms with negative charges which induce an electrical repulsion to the polysulfide anions, and their relatively long chains which can provide additional steric hindrance. Thus, the polysulfide anions can be located around carbon particles, which result in remarkably improved overall electrochemical performance, and also the electrolyte have a function of suppress the formation of lithium dendrites on the lithium anode surface.

Effect of Temperature on the Photovoltaic Performance of Dye-Sensitized Solar Cells Based on an Iodine Quasi-Solid State Electrolyte

Effect of Temperature on the Photovoltaic Performance of Dye-Sensitized Solar Cells Based on an Iodine Quasi-Solid State Electrolyte

Electrospun polymethylacrylate nanofibers membranes for quasi-solid-state dye sensitized solar cells

Polymethylacrylate (PMA) nanofibers membranes are fabricated by electrospinning technique and applied to the polymer matrix in quasi-solid-state electrolytes for dye sensitized solar cells (DSSCs). There is no previous studies reporting the production of PMA nanofibers. The electrospinning parameters such as polymer concentration, applied voltage, feed rate, tip to collector distance and solvent were optimized. Electrospun PMA fibrous membrane with average fiber diameter of 350nm was prepared from a 10wt% solution of PMA in a mixture of acetone/N,N-dimethylacetamide (6:4v/v) at an applied voltage of 20kV. It was then activated by immersing it in 0.5M LiI, 0.05M I2, and 0.5M 4-tert-butylpyridine in 3-methoxyproponitrile to obtain the corresponding membrane electrolyte with an ionic conductivity of 2.4×10−3Scm−1 at 25°C. Dye sensitized solar cells (DSSCs) employing the quasi solid-state electrolyte have an open-circuit voltage (Voc) of 0.65V and a short circuit current (Jsc) of 6.5mAcm−2 and photoelectric energy conversion efficiency (η) of 1.4% at an incident light intensity of 100mWcm−2.