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For this study, the sol gel method was used to synthesize the spinel LiNi0.5Mn1.5O4 (LNMO) electrode material. Structural, morphological, electrochemical, and kinetic aspects of the LNMO have been characterized. The synthesized LNMO was indexed with the Fd3̄m cubic space group. The excellent capacity retention indicates that the spinel framework of LNMO has the ability to withstand high rate charge-discharge throughout long cycle tests. The Li diffusion coefficient (DLi) changes non-monotonically across three orders of magnitude, from 10−9 to 10−12 cm2 s−1 determined from GITT method. The variation of DLi seemed to be related to three oxidation reactions that happened throughout the charging process. A small dip in DLi at the beginning stage of Li deintercalation is correlated with the oxidation of Mn3+ to Mn4+. While two pronounced DLi minima at 4.7 V and 4.75 V are due to the oxidation of Ni2+/Ni3+ and Ni3+/Ni4+ respectively. The depletion of DLi at the high voltage region is attributed to the occurrence of two successive phase transformation phenomena.

Determining the transport properties of charge carriers is essential to understand the factors that affect the conductivity trend of a polymer electrolyte system. In this work, charge carrier transport parameters of polyethylene oxide–based gel polymer electrolytes were estimated from fitting the Nyquist plot with the impedance equation, derived from the equivalent circuit that consists of a resistor in series with a constant phase element. The increase in electrolyte conductivity with temperatures from 303 K to 373 K is attributed to the increase of free ions, n (TPA+ cations and I¯ anions) and not to ionic mobility, μ. The decrease in μ with temperature is associated with the increase in the Stokes drag coefficient due to increase in ion collisions. This work explains how conductivity changes with number density of ions and mobility at various temperatures.

Zinc stannate (Zn2SnO4), zinc ferrite (ZnFe2O4), zinc antimonate (ZnSb2O4) and zinc aluminate (ZnAl2O4) are examples of zinc-based two-cation oxide spinel semiconductors (ZTCOSSs) that have been investigated and employed in many applications. These include applications in solar cells, photocatalysts, batteries, supercapacitors, thermoelectrics and sensors. Zinc-based two-cation oxide spinel semiconductors have peculiar properties that include low electrical resistivity and unique optics. Also, ZTCOSSs permit multiple redox reactions and exhibit magnetic properties depending on the cations. ZTCOSS has the advantages of better optical, electrical and chemical properties over the zinc oxide spinel semiconductor. In this review, the concept of zinc-based two-cation spinel oxides, fabrication techniques and their properties are discussed. Applications of zinc-based two-cation oxide spinel semiconductors are explored and the performance compared with that of single oxides spinel semiconductors.

In this study, gel polymer electrolytes (GPEs) were prepared using polyacrylonitrile (PAN) polymer, ethylene carbonate (EC), propylene carbonate (PC) plasticizers and different compositions of tetrapropylammonium iodide (TPAI) salt. Linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) measurements were done using non-blocking Pt-electrode symmetric cells. The limiting current (Jlim), apparent diffusion coefficient of triiodide ions and exchange current were found to be 12.76 mA cm−2, 23.41 × 10−7 cm2 s−1 and 11.22–14.24 mA cm−2, respectively, for the GPE containing 30% TPAI. These values are the highest among the GPEs with different TPAI contents. To determine the ionic conductivity, the EIS technique was employed with blocking electrodes. The GPE containing 30% TPAI exhibited the lowest bulk impedance, Rb (22 Ω), highest ionic conductivity (3.62 × 10−3 S cm−1) and lowest activation energy. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) techniques were utilized for structural characterization. Functional group interactions among PAN, EC, PC and TPAI were studied in the FTIR spectra of the GPEs. An up-shift of the XRD peak indicates the polymer–salt interaction and possible complexation of the cation (TPA+ ion) with the lone pair of electrons containing site –CN at the N atom in the host polymer matrix. On the other hand, computational study shows that TPAI-PAN based GPE possesses the lowest frontier orbital bandgap, which coincided with the enhanced electrochemical and electrocatalytic performance of GPE. The dye-sensitized solar cell (DSSC) fabricated with these GPEs showed that the JSC (19.75 mA cm−2) and VOC (553.8 mV) were the highest among the GPEs and hence the highest efficiency, η (4.76%), was obtained for the same electrolytes.

Dye-sensitized solar cell (DSSC) which was first introduced by Gratzel and co-workers 29 years ago is very attractive as the next generation sustainable energy device owing to its unique features such as inexpensive, flexibility, eco-friendly, simplicity in fabrication, functional at both indoors and outdoors, and so on. The heart of DSSC is the electrolyte which contains a redox mediator (e.g., I−/I3−). Conventional electrolyte used in DSSC is an organic liquid with the redox couple dissolved in it. Liquid electrolytes have high ionic conductivity but they suffer from leakage and electrochemical corrosion that affect the stability and consequently the cell performance. These have prompted researchers to employ polymer electrolytes particularly in gel form. Many gel polymer electrolytes (GPEs) have been developed but in this article, we pay special tribute to GPEs based on polyacrylonitrile (PAN) due to its high ambient conductivity, good mechanical integrity, and electrochemical stability with good performance.

Dye Sensitized Solar Cell (DSSC) merupakan salah satu bagian dari energi terbarukan yang memiliki potensi besar dengan memanfaatkan energi dari sinar matahari menjadi energi listrik dengan bantuan sensitizer sebagai agen penyerap cahaya. Kemampuan konversi DSSC ditunjukkan oleh nilai Jsc (12,70 mA/cm 2 ), Voc (0,585 V), FF (0,476), dan η (3,54%) yang diperoleh dari pengujian solar simulator . Selain parameter tersebut, karakteristik DSSC dapat juga ditunjukkan dari nilai t tr (0,010 s), t rec (0,080 s), η cc (0,874), D (0,192) dan L D (0,124 mm) melalui IMPS ( Intensity Modulated Photocurrent Spectroscopy ) dan IMVS ( Intensity Modulated Photovoltage Spectroscopy ). Pada artikel ini juga dilaporkan Impedansi antar lapisan DSSC melalui analisis EIS ( Electrochemical Impedance Spectroscopy ). DOI: http://dx.doi.org/10.17977/um024v4i12019p023

Polyacrylonitrile (PAN)–based gel polymer electrolytes (GPEs) consisting of plasticizers ethylene carbonate (EC) and propylene carbonate (PC) and different compositions of tetrabutylammonium iodide (TBAI) salt have been investigated. The GPEs have been characterized by electrochemical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), and X-ray diffraction (XRD) techniques. EIS study shows that the GPE containing 30 wt% TBAI has the lowest bulk impedance, Rb (23 Ω), and highest room temperature ionic conductivity (3.46 × 10−3 S cm−1). Conductivity-temperature relationship in the temperature range studied obeys Arrhenius rule. The Ea value is decreased with TBAI percentage and is the lowest (12.59 kJ/mol) for GPE containing 30 wt% TBAI. From LSV experimental data, the limiting current density (Jlim), apparent diffusion coefficient of triiodide ion ( $$ {D}_{I_3^{-}}^{\ast } $$ ), and exchange current density (J0) have been calculated. The highest value for each of these parameters is 5.00 mA cm−2, 6.59 × 10−7 cm2 s−1, and 0.63 mA cm−2, respectively, for the highest conducting GPE. All samples are amorphous. LSV at stainless steel showed that the electrochemical stability window is 2.2 V. The cyclic voltammetry (CV) was performed from 1 to 1000 cycle which showed good electrochemical stability.

Solution casting technique has been used to prepared chitosan-based polymer electrolyte films. The polymer electrolyte (PE) film containing 55 wt.% of biopolymer chitosan, 45 wt.% of NH4I salt and ...

Li2SnO3 has been synthesized by the sol-gel method using acetates of lithium and tin. The Li2SnO3 precursor was then characterized by thermogravimetric analysis (TGA) and X-ray diffraction (XRD) to...

In this work, several liquid electrolytes (LE) have been prepared. The electrolytes contain tetrapropylammonium iodide (TPAI) salt with different salt content, propylene carbonate (PC), ethylene carbonate (EC), polyethylene oxide (PEO), dimethylformamide (DMF) and (I-/I3-) redox couple LE was used in the Dye-Sensitized Solar Cell (DSSC). DSSCs were fabricated and current density-voltage (J-V) characteristics measured. The highest incident photon conversion efficiency (IPCE) at 520 nm is 45.5% for DSSC with 0.25 g TPAI LE. At AM 1.5, DSSC with LE exhibits efficiency of 6.61% with Jsc= 18.69 mA cm-2, Voc= 0.68V and fill factor (FF) = 0.52.

Sodium-carboxymethylcellulose (NaCMC) films have been developed by solution casting technique. The films were soaked into an optimized aqueous polysulphide electrolyte containing 4 M sodium sulphide (Na2S) and 1 M sulphur (S). The optimized aqueous polysulphide electrolyte has the ambient conductivity of (1.46 ± 0.02) × 10-1 S cm-1. The NaCMC films were soaked for different durations of 30, 60, 68 and 75 s. The highest room temperature ionic conductivity (RTIC) of (2.79 ± 0.09) × 10-5 S cm-1 is exhibited by NaCMC film soaked in polysulphide electrolyte for 68 s. The conductivity-temperature relationship of NaCMC-based polysulphide solid polymer electrolytes (SPEs) follows the Arrhenius rule. The highest conducting SPE exhibits the lowest activation energy (EA) value of 0.38 eV. Ionic coefficient of diffusion (D), ionic mobility (μ) and free ions concentration (n) of the SPEs were determined. The newly developed SPEs are used as electrolyte in quantum dot-sensitized solar cells (QDSSCs) application with the configuration FTO/TiO2/CdS/ZnS/SPE/Pt/FTO. Under 1000 W m-2 illumination, QDSSC with CMC-68 SPE exhibits the highest power conversion efficiency (PCE) of 0.90%. The values of short circuit current (JSC) and PCE are closely related to electron lifetime and recombination rate.

Sodium-ion batteries (SIBs) are normally investigated at room temperature (RT). However, the application of electrical vehicles (EVs) may work at high/low temperatures in a harsh environment. Herei...

A new series of macrocyclic Ni (II) complexes having indolenine and dibenzotetraaza [ 14 ] annulene (DBTAA) moieties were synthesized and tested for their application as sensitizers in dye - sensitized solar cells (DSSCs). The structures are furnished with anchoring groups of ethyl ester (8a, 8b, and 8c) or carboxylic acid (9c) on the indolenine moiety and hexyloxy (8b) or neopentyloxy (8c, 9c) groups on the DBTAA moiety. The best performance was exhibited by dye 9c, which under constant AM 1.5G solar simulation (100 mW cm−2) using I−/I3− electrolyte gave a short-circuit current Jsc = 0.43 mA cm−2, an open-circuit voltage Voc = 0.41 V and a fill factor FF = 0.528, corresponding to an overall conversion efficiency of η = 0.093%. This is the first investigation of macrocyclic DBTAA derivatives as sensitizers for DSSCs applications.

Purpose This paper aims to discuss about the benefits of Cu(NO3)2 applied in coating paint film that consists of plant extract from Cassia Alata. Cu(NO3)2 has been added to the coating paint film as a colour stabilizer and as an antifungal property by forming a zone of inhibition towards fungal growth. Design/methodology/approach The coating paint film resin consists of a mixture of poly (methyl methacrylate) (PMMA) and acrylic polyol. The coating paint film’s performances were observed in terms of visible optical and physical appearance. Findings When exposed to the fungus Trichoderma Sp., a zone of inhibition of 208 mm2 was formed around the coating paint film and therefore it gave the coating paint films an antifungal property. The commission internationale de l’éclairage (CIE) L*a*b* colour coordinate system was used to identify the colour changes in the coating paint film and it was found that the addition of Cu(NO3)2 to the coating paint film has a better colour stability, as it has a lower standard deviation (STD) value of 6.46 than the pure dye coating paint film of 8.95. The gloss of coating paint film with the addition of Cu(NO3)2 was found to be have a more stable gloss based on its smaller STD value at both angles taken at 20° and 60°. Research limitations/implications The Cassia Alata plant has different amount of antifungal properties based on location its growth. Practical implications The coating paint film developed in this study is suitable for indoor applications. Originality/value The plant extract from the Cassia Alata gives the coating paint film an antifungal property.

In this work, solar cells with configuration FTO/ZnO/ZnFe2O4/CdS/ZnS/gel polymer electrolyte (GPE)/Pt/FTO have been fabricated. ZnFe2O4 was spin-coated on ZnO using 0.3, 0.4, 0.5, 0.6 and 0.7 M ZnFe2O4 in 2-methoxyethanol (C3H8O2) solution. Zinc ferrite is known to be stable and environmentally friendly. The phase structure and surface morphology of ZnFe2O4 have been identified by XRD and FESEM, respectively. Using the Williamson Hall equation, the crystallite size is 26, 28, 30, 57 and 63 nm for ZnFe2O4 derived from 0.3, 0.4, 0.5, 0.6 and 0.7 M solutions, respectively. The lattice strain is 0.19. 0.21, 0.23, 1.00 and 1.10% respectively. From UV–Vis spectroscopy the band gap is observed to decrease with ZnFe2O4-2-methoxyethanol (C3H8O2) concentrations. The cell fabricated with the 0.5 M ZnFe2O4 in 2-methoxyethanol (C3H8O2) solution, exhibits a fill factor (FF) of 28%, current density at zero voltage of 0.9 mA cm2 and electromotive force of 150 mV.

Hydrogels comprising 90 wt.% polyvinylpyrrolidone and 10 wt.% poly(methyl methacrylate) have been soaked in distilled water. By taking the mass change for different soaking times the number of water molecules entering the hydrogel can be calculated. A maximum in conductivity has been observed in the conductivity-soaking time plot. The increase and decrease in conductivity over time imply that some water molecules in the hydrogel are mobile (infrared band at 1598 cm-1) and immobile water band observed at 1687 cm-1. These can also be implied from the plot for number density of conductivity contributing water molecules versus soaking time. From the results shown water molecules diffuses at a faster rate when there are less conductivity contributing water molecules

A gel-type polymer electrolyte (GPE) composite based on polyacrylonitrile (PAN) conducting polymer plasticized with ethylene carbonate (EC) and propylene carbonate (PC) doped by different compositions of tetrapentylammonium iodide (TPeAI) salt has been prepared and investigated. Electrochemical impedance spectroscopy (EIS) and linear sweep voltammetry (LSV) techniques have been used to characterize the prepared GPEs. From the EIS study, it has been observed that 30 wt % TPeAIcontaining GPE has the lowest bulk impedance, Rb (32 ohm) and highest room-temperature ionic conductivity (2.4910-3 S cm-1). The conductivity vs temperature diagram in the range of studied temperature studied follows the Arrhenius rule. The values of activation energies, (Ea) are observed to decrease with the increase of the percentage of TPeAI percentage with the lowest values (8.50105 J/mol) for 30% TPeAI containing GPE. From LSV graphs for the GPE systems, various parameters such as the limiting current density (Jlim), the apparent diffusion coefficient of triiodide ion () and exchange current density (J0) have been estimated. The most conducting GPE material shows the highest values of Jlim (3.95 mA.cm-2), (7.86×10-8cm2 s-1) and J0 (0.46 mA.cm-2). The GPEs will be suitable for application in Dye-sensitized Solar Cell (DSSC).

Electrochemical cell for energy storage such as battery and supercapacitor are developing rapidly in recent years. Battery has high specific energy but moderate to low cyclic rate and long recharge time. On the other hand, electrostatic double-layered capacitors (EDLC) is characterized by their extremely fast charge and discharge capability, high power density but relative low energy density. The limitation can be mitigated by having a hybrid of theses energy storage system which is synchronized in accordance to the application. In this work, the characteristics of a EDLC and lead acid battery are characterized and modelled using MATLAB®. Subsequently, a hybrid energy system consists of a combination of (EDLC) and battery is studied. From the model, an energy management scheme is implemented by using an embedded system to manage the charge-discharge rate, to ensure it operate within the safety envelope and maximised operation lifespan.

This chapter reviews the current position as well as future outlook of energy materials used in energy-harvesting, -conversion, -storage, and -saving technologies because energy and the environment represent the top-most challenges for modern society. The chapter centers on the overarching framework of three important issues, namely the sustainability, recyclability, and lifetime of these energy materials. The main reasons are outlined and possible solutions are mapped that address these issues, thereby increasing supply and reducing the demands for energy.

Electrospinning is a unique method in producing polymer nanofibers with diameter typically in the range from 10 nm to 1500 nm. Large length to diameter ratio and small mass to volume ratio of these nano-sizes fibers widens the areas of their application to many industrial uses. In this study, the composite nanofibers were produced by electrospinning method. Cellulose content was incorporated in the PEO polymer host solution at various concentrations. The morphology of the processed fibers has been examined by microscopic techniques: optical microscope and field emission scanning electron microscopy (FESEM). The results obtained shows the formation of fibers with less bead when increasing the cellulose content from 5 to 25 wt.%.

In this work, liquid electrolytes (LEs) and gel polymer electrolytes (GPEs) containing tetrapropylammonium iodide (TPAI) salt, propylene carbonate, ethylene carbonate, N,N-dimethylformamide and (I−/I3−) redox couple have been prepared. For GPEs, the additional material was poly(ethylene oxide). The impedance of these electrolytes was measured using electrochemical impedance spectroscopy to determine their ionic conductivity. Conductivity was found to increase with salt content in LEs whereas in GPEs, conductivity was initially enhanced but it was followed by decrement. The highest ionic conductivity for the GPE and LE were 2.53 mS cm−1 (0.20 g TPAI) and 8.98 mS cm−1 (0.25 g TPAI), respectively at room temperature. Dye-sensitized solar cells (DSSCs) were fabricated using all LEs and the highest conducting GPE. At 100 mW cm−2 illumination, DSSC with LE exhibited the efficiency of 6.61% with short circuit current density, Jsc= 18.69 mA cm−2, open circuit voltage, Voc = 0.68 V and fill factor, FF = 0.52 whereas DSSC using GPE delivered the efficiency of 3.29% with Jsc= 11.78 mA cm−2, Voc = 0.65 V, FF = 0.43. The highest incident photon conversion efficiency (IPCE) at 520 nm is 45.5% for DSSC with 0.25 g TPAI LE and 41.1% for DSSC with GPE at the same wavelength.

In this work, different concentrations of lithium iodide (LiI) have been added to the gel polymer electrolyte (GPE) containing PEO and PVA in equal ratio, tetrabutylammonium iodide (TBAI), ethylene carbonate (EC), dimethyl sulfoxide (DMSO) and iodine crystals (I2). The effect of introducing lithium iodide (LiI) into PEO-PVA blended GPE system having TBAI has been investigated in terms of optical, electrical, thermal and electrochemical characteristics. Fourier transform infrared (FTIR) spectroscopy has been carried out to study the interaction of LiI with the GPEs. The GPE without LiI showed the highest conductivity of 5.50 mS cm−1 at room temperature. With the incorporation of LiI, decrement in conductivity was observed. Dye-sensitized solar cells (DSSCs) with configuration FTO/TiO2/N3-dye/GPE/Pt/FTO have been fabricated and tested under white light of intensity 100 mW cm−2. The DSSC made of GPE with 1.34 wt% LiI exhibited highest efficiency, η of 6.26%.

Purpose The purpose of the paper is to study the effect of color stability on introducing chenodeoxycholic acid (CDCA) into a colored liquid extract from saffron and determine the color quality of the extract over a nine-month period. Design/methodology/approach Six colored liquid samples with different CDCA contents ranging from 0 to 45 Wt.% have been successfully prepared. Chromaticity (C*), color saturation (s), UV-Vis spectroscopy and coloring strength studies have been assessed to determine how CDCA influences the color properties and to study the color quality over time. The color quality was analyzed using the Commission Internationale de l’Eclairage (CIE) system. Findings All results obtained revealed that the addition of CDCA significantly influenced the overall color performance of the saffron extraction. However, the most pronounced improvement was recorded with the use of 45 Wt.% CDCA. The sample exhibited the highest color quality at the end of nine months of storage with highest absorbance: C* value = 91.38, color saturation = 0.96 and coloring strength = 687. Practical implications This preliminary study offers significant findings for further research focused on stability of natural colorants extracted from Spanish saffron that can provide benefits for future applications especially in coating industry, food, agriculture, medicine and others. Originality/value The values of this work can be observed from the information and evidence provided by CIE color stability in terms of chromaticity and saturation, as well as UV-Vis spectrophotometric measurement. It showed that the addition of CDCA additive can help to prolong and enhance the natural colorant properties from Spanish saffron (Crocus sativus L.) for nine month of storage. This proved that by adding additives such as CDCA the saffron colorant can be maintained. To the best of the authors’ concern, this is the first time CDCA is used to prevent color degradation of natural colorant from saffron.

Purpose The purpose of this paper is to study the colour stability and water content resistivity of the green colour coating paint film (consisting of chlorophyll) during exposure to ultraviolet A (UV-A). Design/methodology/approach The natural green dye was prepared by immersing Cassia alata L. leaves in absolute ethanol. The extract was prepared in two batches of dye samples where one of it was a pure dye and the other was added with 3 Wt. % Cu(NO3)2 as an additive. Polymer blend as a binder was prepared by mixing poly(methyl methacrylate) (PMMA) and commercial acrylic polyol. The blended polymer was mixed with the natural dye in a specific ratio and applied as coating paint film on glass panel surfaces. The visible spectrum stability (colour stability) and water content resistivity of the coating paint films during exposure to UV-A were monitored. Findings Addition of Cu(NO3)2 had improved the colour stability of the coating paint film. Fourier transform infrared spectroscopy analysis showed that both coating paint films do not absorb water and are resistive to water content. Research limitations/implications The ability of Cu(NO3)2 as an colour stability additive to the natural green dye applied in the coating paint film. Practical implications The coating paint film developed in this work is suitable to be applied on glass substrates. Originality/value The colour stability of the coating paint film was analysed by using the reflectance spectrum.

Carbon materials have potential applications in perovskite solar cell because of their excellent electronic properties and low cost. In this paper, we report, for the first time, activated carbon a...

Purpose The purpose of this paper is to evaluate the potential use of natural colorant extracted from fruit flesh and leaves of Cucumis melo L. (C. melo L.) in coating applications. Design/methodology/approach Carotenoids and chlorophylls compounds were extracted from C. melo L. fruit flesh and C. melo L. leaves with the best extraction solvents. Both compounds were tested at various pH for colour stability tests. Then, the most stable pH of both extracts was mixed with 20 per cent poly methyl methacrylate (PMMA) together with tetrahydrofuran and acrylic polyol to form a coating system on glass slides. The coated glass slides were exposed to three different temperatures. The effects of heat on the coated glass slides were evaluated using spectrophotometer at 400-700 nm wavelengths. Findings Results revealed that carotenoids extracted from C. melo L. were less stable to be applied in coating applications since the colour degraded in a very short time; however, the chlorophylls extracted were more stable where the colour retained for longer duration. Originality/value The method of the plant pigment production of C. melo L. with PMMA was a modified method that could give other various applications as natural product based on plant pigments.

The introduction of electric vehicles (EVs) into the automotive market has boosted the advancement of energy storage technology. Although lithium-ion batteries (LIBs) could provide a solution to th...

A new gel electrolyte comprising methylcellulose (MC), LiBOB and succinonitrile (SN) has been prepared with dimethyl sulfoxide (DMSO) as solvent. The electrolyte with composition 8.73 wt % MC–2.92 wt % LiBOB–1.01 wt % SN–87.34 wt % DMSO exhibits the highest conductivity of 1.18 mS cm-1 at 25 °C. On partially substituting LiBOB with TMAI, the sample designated as TMAI 95 has the highest conducting composition of 8.70 wt % MC–0.14 wt % LiBOB–1.01 wt % SN–2.77 wt % TMAI–0.35 wt % I2–87.03 wt % DMSO. The conductivity is 1.96 mS cm−1. This sample is used to fabricate a dye sensitized photovoltaic cell that converts photons to electricity at an efficiency of 3.46%. The conductivity of this sample has been enhanced to 3.08 mS cm−1 on addition of 1.0 wt % butyl-methyl immidazolium iodide (BMII) ionic liquid and the efficiency of the cell fabricated is 4.63%. Total replacement of LiBOB component in the electrolyte with the same amount of LiI results in a conductivity increase of ∼23.5% and the DSSC exhibits a 5.72% efficiency.

In this paper, we develop the hybrid perovskite-based n-i-p solar cell using a simple, fast and low-cost dip-coating method. Hot solution and the pre-annealed substrate are used for coating the perovskite thin film by this method this is further used for studying its structural and electrical properties. UV–vis spectroscopy is carried out for calculating the band gap of the hybrid perovskite layer which is ∼1.6 eV. X-ray spectroscopy confirms that the formation of hybrid perovskite layer. The profilometer is used to study the surface roughness and also for measuring the thickness of the perovskite layer with varying substrate temperature. The optimized sample was further used for cross-sectional SEM image to verify the thickness measured from the profiler. The electrical parameter of JV characteristic with varying temperature is tabulated in the table. Whereas, the perovskite sensitized solar cell exhibits highest short circuit current density, Jsc of 11 mA cm−2, open circuit voltage, Voc of 0.87 V, fill factor of 0.55 and efficiency, η of >5%.

Silicone-modified epoxy polymeric matrix was successfully fabricated and reinforced with 1–2 wt% SiO2, TiO2, and TiSiO4 nanoparticles. Fourier-transform infrared spectroscopy, contact angle measurements, differential scanning calorimetry, and field-emission scanning electron microscopy together with energy-dispersive X-ray spectroscopy were employed to investigate different characteristics of the prepared coatings. To simulate operating conditions, all samples were characterized via electrochemical impedance spectroscopy (EIS) after being subjected to different conditions. Corrosion under static conditions, in which the samples were exposed to a static electrolyte without further change in other parameters, was investigated. Furthermore, to study the effects of ultraviolet (UV) radiation in accelerating the degradation of the coatings, samples were characterized after being subjected to UV while immersed statically in the electrolyte. Additionally, the corrosion protection performance was investigated after subjecting the coated substrates to dynamic conditions involving continuous movement of the sample in the electrolyte, simulating continuous wear of the coated surfaces. Compared with the static condition, the EIS results revealed the vital role of the silicone resin and nanoparticles in improving the stability of the coating film against corrosion degradation in the presence of UV radiation, while poor performance in dynamic condition was recorded for all the coating systems.

Low ionic conductivity in gel polymer electrolytes with large cations is undoubtedly a critical issue. This research’s main objective was to explore potassium iodide influences on the conductivity in gel polymer electrolytes. PVA-based gel polymer electrolytes (GPEs), including tetrapropyl ammonium iodide and potassium iodide have been prepared. The GPEs have been characterized by X-ray diffraction (XRD) and electrical impedance spectroscopy (EIS). The GPEs prepared haves been recognized as an amorphous region through the X-ray diffraction analysis. The GPE sample’s conductivity (100 wt% of tetrapropyl ammonium iodide) of 6.24 × 10−3 S cm−1 was the lowest. The existence of potassium iodide in the GPE system improves the conductivity. The conductivity of 9.72 × 10−3 S cm−1 of GPE containing 30 wt% of tetrapropyl ammonium iodide and 70 wt% of potassium iodide was the highest derived from the EIS analysis. All prepared GPEs have the potential to be used for dye-sensitized solar cell applications. The dye-sensitized solar cell efficiency has been improved by ~30% if potassium iodide exists in the GPE system.

Present work is aimed to explore the electrical and structural behavior of polymer composite consists of poly (vinylidene difluoride)–lithium bis(oxalato)borate under tens of kGy neutron dose. PVDF-LiBOB samples were prepared via solution casting method. The samples were irradiated with neutron doses of 15, 23, 31, 39 and 47 kGy using Reaktor TRIGA PUSPATI at Malaysian Nuclear Agency. X-ray diffraction analysis reveals an increase of crystallinity with the neutron doses, which indicates an improvement of the mechanical strength of the material. Deconvolution of Fourier transform infrared spectra from 1830 to 1760 cm−1 confirms a reduction of free ions following the radiation dose. Electrochemical impedance spectroscopy showed a decrease in ionic conductivity with an increase in neutron dose, which indicates the non-conducting/radiation resistant behavior of the studied polymer composite. Furthermore, the dielectric constant shows an inverse behavior with the relaxation time following the increase of neutron dose until 47 kGy. Key transport parameters such as mobile charge concentration, mobile ion mobility and mobile ion diffusion coefficient supports the evidence to the increased radiation resistant behavior of PVDF-LiBOB with the increase of neutron doses. As such, the studied low-cost polymer composite (PVDF-LiBOB) has the potential to be used as a radiation resistant coating materials for protecting of sophisticated industrial devices (e.g., energy storage devices) which may provide a better device stability.

In this work, poly (methyl methacrylate), PMMA based gel polymer electrolytes (GPEs) have been studied. Lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) was selected as lithium-ion donor and tetraethylene glycol dimethyl ether (TEGDME) as a solvent. The highest conducting sample was obtained at 25 wt% LiTFSI with ionic conductivity value of 2.80 mS cm−1. The dielectric constant of GPEs sample follows the conductivity trend. The percentage of free ions is observed to increase up to electrolyte containing 25 wt% LiTFSI salt. Beyond that, the free ions percentage decreased. Lithium-ion transference number for the highest conducting sample is 0.47. The highest ionic conducting sample show good electrode-electrolyte interfacial stability and is suggested suitable in lithium-oxygen batteries. The charge and discharge capacities in the first cycle were 0.87 and 1.23 mAh cm−2, respectively. Formation of Li2O2 can be observed by XRD pattern of the air cathode during the discharge.

Nanochitosan (NCH) was prepared to act as a nanofiller reinforcing agent that had been incorporated in a protective coating for corrosion protection using high-molecular-weight chitosan. In this study, a series of epoxy resin based nanocomposite coatings were prepared with various of NCH loading ratio and applied on mild steel substrates under ambient conditions. The surface morphology and structural characterization of the NCH and nanocomposite coatings were carried out using Field Emission Scanning Electron Microscope (FESEM), X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. Optical characterization of the nanocomposite specimens was examined by using UV–vis spectroscopy at a range of 300–800 nm in transmission mode. The thermal analysis of the nanocomposite coating was employed using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The corrosion protection performances of the nanocomposite coated mild steel substrates were comparatively studied using electrochemical impedance spectroscopy (EIS). The results showed that all the epoxy resin based nanocomposite coating containing NCH significantly increases the anticorrosion properties.

This study deals with the characterization of methylammonium lead iodide (MAPbI3) material and the fabrication of perovskite solar cells using gel polymer electrolyte as the charge transport medium. The crystalline lead–based perovskite has been verified by x-ray diffraction (XRD). The [100], [200], [210], [211], [220], [300] and [222] reflection planes can be observed at 2? angles of 14.10°, 28.35°, 31.90°, 34.95°, 40.40°, 43.15° and 50.20°, indicating a cubic crystal symmetry for CH3NH3PbI3. EDX spectrum showed a Pb:I ratio of approximately 1:3 as in CH3NH3PbI3. The band gap for lead-based perovskite is 1.45 eV estimated from UV-Vis absorption spectroscopy. The nanocrystalline MAPbI3 have been observed using field emission scanning electron microscopy (FESEM), where the average cuboid size of perovskite nanocrystals is 380 nm. The cell have been fabricated using gel polymer electrolyte with composition 17.02 wt.% PVA–13.93 wt.% TBAI–0.96 wt.% I2– 68.09 wt.% DMF. The cell exhibits a power conversion efficiency (PCE) of 1.28% with open circuit voltage (Voc) 0.58 mV, short circuit current density (Jsc) 3.74 mA cm?2 and fill factor (FF) 59.18%.

Hybrid polymeric based nanocomposite coating systems (NCs) were fabricated by solution intercalation method with the use of epoxy (E) and polydimethylsiloxane (PDMS) as the host hybrid polymeric matrix and different weight ratio of SiO2 nanoparticles, ranging from 2 wt. % to 8 wt. %, as the reinforcing agents. The effects of introducing PDMS as a modifier to epoxy resin, as well as, the influence of embedding SiO2 nanoparticles within the developed matrix were evaluated via utilizing X-ray diffraction (XRD), contact angle measurements (CA), field emission scanning electron microscope (FESEM), and electrochemical impedance spectroscopy (EIS). XRD and FESEM results revealed the good dispersion of the nanoparticles within the polymeric matrix and confirmed the efficiency of the solution intercalation method. CA findings confirmed the achievement of hydrophobic surface after modifying epoxy resin with PDMS with CA value at 96° for epoxy-PDMS coating system (ES 0). Also CA results indicated the ability of SiO2 nanoparticles to participate in developing more hydrophobic surface as CA value up to 132° was achieved with utilizing 6 wt% SiO2 loading ratio. The results obtained from EIS studies revealed that the coating system with 2 wt% had the best anticorrosion performance and have demonstrated an intact behavior over all the immersion period without any sign of coating damage or degradation.

High efficiency of 9.61% has been produced for dye sensitized solar cell using a phthaloylchitosan based gel polymer electrolyte. The gel polymer electrolytes have been optimized by varying the amount of tetrapropylammonium iodide (TPAI) and 1-butyl-3-methylimidazolium iodide (BMII) ionic liquid (IL). The highest ionic conductivity of gel polymer electrolyte containing 8 wt.% IL was obtained with the value of 13.5 mS cm(-1). The temperature dependence ionic conductivity follows Arrhenius rule. The highest conducting electrolyte also exhibits the highest diffusion coefficient of triiodide ion which is 3.9 X 10(-7) cm(-2) s(-1). The optimized gel polymer electrolyte exhibits the highest short circuit current density of 19.68 mA cm(-2). (C) 2017 Elsevier Ltd. All rights reserved.

Dye-sensitized solar cells (DSSCs) were prepared with natural dyes as sensitizer and liquid electrolyte based on LiBOB polymer. DSSCs with chlorophyll dyes exhibited a better performance in LiBOB-based liquid electrolyte without LiI while anthocyanin and mangosteen dyes achieved higher performance in LiBOB-based liquid electrolyte with addition of LiI. Overall efficiency and fill factor of DSSCs varied from 0.09 to 0.64% and 27 to 66%, respectively. LiBOB-based liquid electrolyte is also suitable in DSSC utilizing N3 dye as sensitizer with significantly better performance than natural dyes. The better performance of natural dye DSSC with LiI inclusion in the electrolyte is attributed to the high conductivity of the electrolyte as a result of more ion-pairs formation.