Papers by Author: Marisa Arunchaiya

Paper TitlePage

Authors: Voranuch Somsongkul, Atchana Wongchaisuwat, Attera Worayingyong, Marisa Arunchaiya
Abstract: Dye-sensitized solar cell (DSSC) is considered as the next generation low cost photovoltaic device, and one of the important components is the counter electrode which reduces the I3- ions generated after electron injection from iodide into the oxidized sensitizer. In this work composite material of carbon black and LaCoO3 synthesized by sol-gel method has been investigated to replace the platinized counter electrode for quasi-solid-state dye-sensitized solar cells. From cyclic voltammogram, it was found that carbon black catalyzed with LaCoO3 exhibited increased reduction current compared with that of carbon black without LaCoO3. This was consistent with increased surface roughness depicted from scanning electron microscopy (SEM) image. The electrochemical impedance spectroscopy (EIS) of DSSCs using carbon black-LaCoO3 composite as counter electrode revealed lower charge-transfer resistance (Rct) than that using carbon black. The highest conversion efficiency of 5.40% was obtained from DSSC (active area 1 cm2) fabricated with quasi-solid composite polymer electrolyte using carbon black-LaCoO3 (95:5 ratio by weight) compared to 5.23% obtained from DSSC equipped with platinum counter electrode. The performances of the quasi-solid-state DSSCs sensitized with N719 and natural dyes were examined and it was concluded that the carbon black-LaCoO3 composite was compatible with platinum coated counter electrode for DSSCs.
451
Authors: Rabat Boonpong, Attera Worayingyong, Marisa Arunchaiya, Atchana Wongchaisuwat
Abstract: The utilization of zinc anode for zinc-based battery is limited due to low cycling life, shape change and ZnO passivation on the electrode surface. The electrochemical behavior of zinc anode in the presence of the additives added to the electrodes or the electrolytes have been reported. In this work, LaCoO3 was used as an additive to improve the electrochemical properties of the zinc oxide anode. LaCoO3 synthesized by sol gel method (Schiff base complex) was added to zinc oxide powder (99.9%) with the weight ratio of 1:0.001, 1:0.002 and 1:0.003. The relative ZnO/LaCoO3 ratios were confirmed by particle induced x-ray emission (PIXE) technique.The electrochemical behavior of the ZnO/LaCoO3 electrodes in 6M KOH solution were investigated by voltammetry and electrochemical impedance spectroscopy (EIS). The cyclic voltammogram showed that ZnO/LaCoO3 gave higher anodic current and ZnO passivation delayed. The EIS spectra showed that charge transfer resistances of the ZnO/LaCoO3 anodes due to zinc oxidation were higher than that of ZnO electrode
596
Authors: Voranuch Somsongkul, Surassawatee Jamikorn, Atchana Wongchaisuwat, San H. Thang, Marisa Arunchaiya
Abstract: The composite polymer electrolyte consisting of poly (ethylene oxide) (PEO), KI, I2 and TiO2 was blended with low molecular weight poly (ethylene glycol) (PEG) and (PEG-MA)-Ru. The SEM images of these blended PEO electrolytes showed better dispersion of materials and the electrochemical impedance spectroscopic study showed an increase in conductivity compared to that of composite PEO electrolyte. These results were consistent with enhanced efficiency of DSSCs using these blended PEO electrolytes. The energy conversion efficiencies of DSSCs using composite PEO-PEG, PEO-(PEG-MA)-Ru and PEO-PEG-(PEG-MA)-Ru polymer blend electrolytes were 5.47, 5.05 and 5.28, respectively compared to 4.99 of DSSC using composite PEO electrolyte. The long-term storage of unsealed DSSCs at room temperature for 93 days demonstrated that the cell efficiency gradually decreased to 0.49-1.88%. DSSCs assembled with composite polymer blend electrolyte showed a slower decrease than that of DSSC using composite PEO electrolyte. It was found that the composite PEO-PEG-(PEG-MA)-Ru polymer blend electrolyte of 1.0:0.1:0.1 weight ratio gave the best improvement in stability of DSSCs.
186
Authors: Atchana Wongchaisuwat, Rapat Boonpong, Attera Worayingyong, Marisa Arunchaiya
Abstract: The electrochemical behaviors of zinc anode in the presence of the additives added to the electrodes are presented. LaCoO3 was used as an additive to improve the electrochemical properties of the zinc anode. LaCoO3 synthesized by sol gel method (Schiff base complex) was added to Zn and ZnO powder with the weight ratios of 1:0.05 and 1:0.002 respectively. The electrochemical properties of the zinc and zinc/LaCoO3 electrodes in 6M KOH solution were investigated by voltammetric technique and electrochemical impedance spectroscopy (EIS). The cyclic voltammograms showed that zinc electrodes with LaCoO3 additive gave higher anodic currents and ZnO passivation delayed. The cathodic Tafel plot indicated that the hydrogen overpotential shifted toward more negative value. The EIS revealed that the charge transfer resistances of the zinc/LaCoO3 electrodes were higher than that of zinc electrodes.
581
Authors: Suthida Vivekaphirat, Chaiyuth Saekung, San H. Thang, Atchana Wongchaisuwat, Marisa Arunchaiya
Abstract: Quasi-solid/solid polymer electrolytes have been the subject of extensive research for an alternative of liquid electrolyte for dye-sensitized solar cells (DSSCs) because of their advantages such as alleviated leakage, lower environmental impact and ease of device fabrication. In this work, the performance of the unsealed quasi-solid-state DSSCs based on composite poly (ethylene oxide) (PEO) electrolyte and N719 dye-sensitizer was examined on aging under atmospheric condition. The energy conversion efficiency of DSSC using the composite PEO electrolyte was 5.62 % under sun simulated light, AM 1.5 (100 mW cm-2) but gradually decreased to 0.95 % on aging for 90 days. An additional layer of poly(3,4-ethylenedioxythiophene) (PEDOT) electrolyte was incorporated with the composite polymer electrolyte for DSSC fabrication. The PEDOT layer was prepared by electrochemical polymerization of bis-ethylenedioxythiophene (bis-EDOT) and characterized by Raman spectroscopy and cyclic voltammetry. It was found that the energy conversion efficiency of DSSC based on the composite polymer electrolyte incorporated with PEDOT layer was 5.57 % and gradually decreased to 1.76 % under the same aging condition. Thus an additional layer of PEDOT electrolyte provided an improved stability of DSSC.
852
Showing 1 to 5 of 5 Paper Titles