Improvement of dye sensitized solar cells efficiency utilizing diethyl carbonate in PVA based gel polymer electrolytes

Low conductivity of gel polymer electrolytes (GPEs) containing double iodide salts is critical for efficiency in dye-sensitized solar cells (DSSCs). The presence of diethyl carbonate (DEC) plasticizer affects the amorphousness and ionic conductivity of polyvinyl alcohol (PVA)-based GPEs and DSSCs performance. In this work, PVA-based GPEs containing a variation of DEC have been produced, characterized, and applied in the DSSCs fabrication. The structural properties of GPEs were analyzed using X-ray diffraction (XRD). The ionic conductivity was determined from electrical impedance spectroscopy (EIS). Based on XRD, GPEs for all prepared compositions have been identified as an amorphous phase. From the EIS measurement, it was found that GPE with the composition of 5.46 PVA - 8.19 EC - 10.92 PC - 60.06 DMSO - 5.73 TPAI - 5.73 KI - 1.34 I2 - 2.57 DEC (in wt. %) having highest conductivity of 11.19 ± 0.20 mS cm-1 with activation energy, Ea of 0.09 eV. The graph of conductivity versus temperature following the Arrhenius rule has been plotted. The GPEs dominate the highest conductive with 2.57% of DEC and showed the DSSCs efficiency of 6.42%. Common DSSCs parameters resulted in short-circuit current density (Jsc) of 17.58 mA cm-2, fill factor (ff) of 0.63, and open-circuit voltage (Voc) of 0.58 V. In conclusion, DEC improves the ionic conductivity as well as amorphous properties of the GPE, and therefore enhance the DSSCs' efficiency

Ionic conductivity of polyvinyl alcohol-based gel electrolyte containing diethyl carbonate plasticizer for supercapacitor application

In this study, diethyl carbonate (DEC) as a plasticizer have been added to the gel electrolytes (GEs) system to influence the conductivity and storage performance of supercapacitor. The GE was prepared through a stirring method consisting of ethylene carbonate (EC), propylene carbonate (PC), potassium iodide (KI), polyvinyl alcohol (PVA) and dimethyl sulfoxide (DMSO). Consecutively, 5 wt. % DEC as a plasticizer was added for all samples. The GE preparation started with stirring all materials and heated until a homogenous gel was formed. The prepared GEs have been characterized with electrochemical impedance spectroscopy (EIS), which utilized to study the ionic conductivity of them. Sample with 15 wt. % of DEC in GE has the ionic conductivity of ~6 x 10-3 Scm-1. This study shows that by adding DEC will cause the ionic conductivity improved which is suggested that this DEC enhanced the ion’s mobility in the GEs’ structures. In cyclic voltammetry, the gel electrolyte with 15 wt.% DEC attain the highest specific capacitance of 55.56 Fg-1 (scan rate of 10 mV s-1). The charge-discharge curve of gel electrolyte acquires a shark fin-like shape which is alike with an ideal supercapacitor symmetric triangle shape. To summarize, the development of high conductivity GE may provide the path for high-performance supercapacitor

Electrochemical Performance Of Molybdenum Disulfide Supercapacitor Electrode In Potassium Hydroxide And Sodium Sulfate Electrolytes

Two-dimensional materials have attracted growing interest in research because of their specific electronic, physical, optical and mechanical properties. Molybdenum disulfide was theoretically investigated as novel energy storage materials because of its unusual physicochemical properties. This paper describes easy approach to fabricate molybdenum disulfide (MoS2) electrode using slurry technique on conducting substrate namely Ni foam as current collector for supercapacitor device application. This MoS2 electrode exhibits relatively good specific gravimetric capacitance, (Csp) of 11.12 to 12.38 Fg-1 at 1 mVs-1 scan rate. Moreover, galvanostatic charge-discharge displays symmetrical triangular curves which attributed to the fast charge-discharge process (in seconds). These results show that MoS2 active material can be charged and discharged reversibly between 0.2 and 1.0 V (in 6 M KOH) and between 0.3 and 1.0 V (in 0.5 M Na2SO4). From cyclic stability test exhibits capacitance retention of up to 83% and 64% after 1000 cycles in 6 M KOH and 0.5 M Na2SO4, respectively. The MoS2 electrode is thus a promising material for future application of the supercapacitor

Direct Observation Of Graphene During Raman Analysis And The Effect Of Precursor Solution Parameter On The Graphene Structures

Controlling the precursor solution parameter in preparing active catalyst film is critical in sol-gel process. The aim of this work is to validate the precursor solution parameter that affects the structural properties of graphene. Active Co3O4 film was prepared using precursor solution from cobalt acetate tetrahydrate in two different concentrations; 0.025 M and 0.05 M. One batch of the precursor solution was directly spin coated onto the substrate's surface meanwhile the second batch was kept for 4 days aging process. The studied spin speeds were 2000 rpm and 6000 rpm, and spin coated for 60 s. The active Co3O4 film was achieved by annealing at 450 °C and the graphene was grown at 900 °C of chemical vapor deposition (CVD) processing temperature for 5 min with the presence of ethanol as the carbon feedstock. The structural properties and morphology of the as-grown graphene synthesized from active Co3O4 film were characterized by Raman spectroscopy, optical microscope, and field emission scanning electron microscope (FESEM). The results demonstrated that concentration of precursor solution and the aging process affected the performance of the as-grown graphene. Agglomerates were formed in sample with 0.05 M of Co acetate tetrahydrate, however it was found that the Raman peaks intensity increased as compared to the 0.025 M sample. The precursor with 0.05 M has an acceptable chemical stability though aged for 4 days and contributed to the graphene growth. The spin coating speed was found not to affect the graphene growth at all. For aging effect, concentration 0.025 M shows unstable condition as compared to concentration 0.05 M when the precursor solution was aged for 4 days. Nonetheless, for the quality of the as-grown graphene, the ratio of Raman 2D-band over G-band intensities was less than 1.0, indicated that the graphene was in multi-layer form

A comprehensive review of filler, plasticizer, and ionic liquid as an additive in GPE for DSSCs

Low ionic conductivity in gel polymer electrolytes (GPEs) affects low dye-sensitized solar cells (DSSCs) performance is a crucial issue. Generally, the GPEs contain polymer (act as solvent holder), solvent, and salt (as ions provider). Usually, the GPE-based DSSCs are assembly with three necessary compartments: working electrode, GPE, and platinum electrode. The DSSCs parameters are included open-circuit voltage, Voc; short-circuit current density, Jsc; fill factor, ff and efficiency, %. This review's main objective was to explore an additive such as plasticizer, filler, and ionic liquid effects on the ionic conductivity in GPEs by improving ions mobility and expanding the free volume of the GPE. The impact of additives in the GPE is also expected to enhance the DSSCs performance by increasing the Jsc, Voc, ff, and efficiency. This comprehensive review discussed the latest progress of GPE utilizing the additive by listing the literature from the recent ten years

Characterization of reduced graphene oxide/activated carbon-based electrode containing mixing CMC-SBR binder and application in supercapacitor

In this work, variation of mixing a combination of carboxymethylcellulose (CMC) and styrene-butadiene rubber (SBR) as both used as the binder in the electrode has been studied. The purpose of using CMC-SBR as the binder in the electrode is to achieve a high supercapacitor performance. The electrode preparation has been carried out by mixing the reduced graphene oxide (rGO) and activated carbon (AC) in a blender. The binder preparation started by dissolving the CMC and SBR in the deionized water using a clean glass container. Then, rGO/AC has been stirred with the CMC-SBR for 60 minutes until a homogenous slurry formed. All electrodes have been characterized with Raman spectroscopy. The electrochemical tests such as cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) for all electrode compositions were performed. The electrode with 4:6 (in weight percentage) of CMC-SBR shows the highest specific capacitance (Csp) of 59.65 F g-1 (CV scan rate of 1 mV s-1) and 12.82 F g-1 from GCD test. This confirmed that the electrode containing 4 wt.% of CMC and 6 wt.% of SBR resulting in the best composition, which is reliable and practical for the supercapacitor application

A comprehensive review of filler, plasticizer, and ionic liquid as an additive in GPE for DSSCs

Low ionic conductivity in gel polymer electrolytes (GPEs) affects low dye-sensitized solar cells (DSSCs) performance is a crucial issue. Generally, the GPEs contain polymer (act as solvent holder), solvent, and salt (as ions provider). Usually, the GPE-based DSSCs are assembly with three necessary compartments: working electrode, GPE, and platinum electrode. The DSSCs parameters are included open-circuit voltage, Voc; short-circuit current density, Jsc; fill factor, ff and efficiency, %. This review’s main objective was to explore an additive such as plasticizer, filler, and ionic liquid effects on the ionic conductivity in GPEs by improving ions mobility and expanding the free volume of the GPE. The impact of additives in the GPE is also expected to enhance the DSSCs performance by increasing the Jsc, Voc, ff, and efficiency. This comprehensive review discussed the latest progress of GPE utilizing the additive by listing the literature from the recent ten years

Structural Characterization And Electrochemical Performance Of Nitrogen Doped Graphene Supercapacitor Electrode Fabricated By Hydrothermal Method

The introduction of nitrogen (N) into graphene is of great focus as it escalates overall device performance as the introduction of N atoms improves the electronics of the graphene. In this work, the N-doped graphene electrode was prepared by using hydrothermal method where graphene nanoplatelet was used as active material and aqueous ammonia as the nitrogen source. The electrode was then used as the supercapacitor electrode. From Raman analysis, the ID/IG ratio of N-doped graphene has a higher value than that of pristine graphene. This indicates the N-doped graphene possessed more defects and has a higher degree of disorder within the graphene sheet. For X-ray diffraction analysis, the result exhibits a broad peak at 2θ = 26.3o, corresponding to the graphitic profile with an interlayer spacing of 3.57 Å. X-ray photoelectron spectroscopy analysis proved that there is a presence of nitrogen on the graphene surface, with 2.35 % of the atomic concentration. From the cyclic voltammetry, all curves showed an almost rectangular shape at the scan rates of 10 to 100 mVs-1. The calculated specific gravimetric capacitance is 25.2 F g-1 at 10 mV s-1. In addition, charge-discharge analysis confirmed the typical behavior of electric double layer capacitor from the linear symmetric slope

Polyvinyl alcohol (PVA) based gel electrolytes: Characterisation and applications in Dye-sensitized solar cells / Mohd Fareezuan Abdul Aziz

Three systems of gel polymer electrolytes have been prepared in this work. First system was PVA-DMSO-EC-PC-KI-I2 gel polymer electrolytes. In the first system, various amount of KI salt were added. The highest conductivity of gel polymer electrolyte for the first system was 12.50 mS cm-1 for the gel polymer electrolyte with the composition of 5.58 wt. % of PVA - 8.37 wt. % of EC - 11.16 wt. % of PC - 61.37 wt. % of DMSO - 11.72 wt. % of KI - 1.80 wt. % of I2. To this composition, part of KI was replaced with the quaternary ammonium iodide salt which is TMAI, TPAI and TBAI for the second system. The conductivity of the gel polymer electrolyte decreased with the increasing amount of quaternary ammonium iodide salts. The best electrolyte in systems 2 which gave the highest efficiency of 5.51 % and 5.80 %, respectively have been chosen for incorporation with diethyl carbonate (DEC) plasticizer (systems 3). With the addition of DEC plasticizer, the conductivity of the gel polymer electrolyte and efficiency of DSSC were enhanced. The highest efficiency of 7.5 % was obtained for the DSSC having 5.47 wt. % of PVA - 8.21 wt. % of EC - 10.95 wt. % of PC - 60.22 wt. % of DMSO - 3.45 wt. % of KI - 8.05 wt. % of TBAI - 1.08 wt. % of I2 - 2.57 wt. % of DEC. The interaction of gel polymer electrolytes have been studied via fourier transform infrared (FTIR) spectroscopy. The peak shifting observed for S=O, O-H, C-O-C and C=O bands indicates that the interaction has occurred. X-ray diffraction (XRD) pattern reveals that all gel polymer electrolytes are amorphous

Effect of the potassium iodide in tetrapropyl ammonium iodide-polyvinyl alcohol based gel polymer electrolyte for dye-sensitized solar cells

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