The Experts below are selected from a list of 11013 Experts worldwide ranked by ideXlab platform
Tetsuya Osaka - One of the best experts on this subject based on the ideXlab platform.
-
an electrochemical Double Layer Capacitor using an activated carbon electrode with gel electrolyte binder
Journal of The Electrochemical Society, 1999Co-Authors: Tetsuya Osaka, Xingjiang Liu, Masashi Nojima, Toshiyuki MommaAbstract:An electric Double Layer Capacitor (EDLC) was prepared with an activated carbon powder electrode with poly(vinylidene fluoridehexafluoropropylene) (PVdF-HFP) based gel electrolyte. Ethylene carbonate (EC) and propylene carbonate (PC) were used as plasticizer and tetraethylammonium tetrafluoroborate (TEABF4) was used as the supporting electrolyte. An optimized gel electrolyte of PVdF-HFP/PC/EC/TEABF4 5 23/31/35/11 mass ratio exhibited high ionic conductivity of 5 3 10 23 S cm 21 , high electrode capacitance, and good mechanical strength. An electrode consisting of activated carbon (AC) with the gel electrolyte as the bind er (AC/PVdF-HFP based gel, 7/3 mass ratio) showed a higher specific capacitance and a lower ion diffusion resistance within the electrode than a carbon electrode, prepared with PVdF-HFP binder without plasticizer. This suggests that an electrode mixed with the gel electrolyte has a lower ion diffusion resistance inside the electrode. The highest specific capacitance of 123 F g 21 was achieved with an electrode containing AC with a specific surface area of 2500 m 2 g 21 . A coin-type EDLC cell with optimized components showed excellent cycleability exceeding 10 4 cycles with ca. 100% coulombic efficiency achieved when charging and discharging was repeated between 1.0 and 2.5 V at 1.66 mA cm 22 .
-
all solid state electric Double Layer Capacitor with isotropic high density graphite electrode and polyethylene oxide liclo4 polymer electrolyte
Journal of The Electrochemical Society, 1996Co-Authors: Xingjiang Liu, Tetsuya OsakaAbstract:An isotropic high-density graphite was used as a polarizable electrode of all-solid state electric Double-Layer Capacitor using polyethylene oxide (PEO) or gel PEO electrolyte. The all-solid-state Capacitor with high-density graphite electrodes possesses higher differential capacity than the other flat electrodes in PEO/LiClO{sub 4} ([EO]/[Li{sup +}] = 8:1) solid polymer electrolyte at 80 C or PEO/PC/LiClO{sub 4} ([EO]/[PC]/[Li{sup +}] = 8:8:1) gel electrolyte at ambient temperature. The capacitance of the electric Double Layer of the high-density graphite electrode was strongly influenced by the cell temperature and concentration of LiClO{sub 4}, because of the different state of the polymer crystallinity and different interface contact state between the high-density graphite electrode and the solid electrolyte. The all-solid-state Capacitor with PEO/LiClO{sub 4} ([EO]/[Li{sup +}] = 8:1) solid polymer electrolyte and PEO/PC/LiClO{sub 4} ([EO]/[PC]/[Li{sup +}] = 8:8:1) gel electrolytes showed good charge/discharge behavior with a relatively high capacitance at 80 and 20 C, respectively.
M F Z Kadir - One of the best experts on this subject based on the ideXlab platform.
-
Structural, impedance and electrochemical Double-Layer Capacitor characteristics of improved number density of charge carrier electrolytes employing potato starch blend polymers
Ionics, 2020Co-Authors: A. A. Azli, Shujahadeen B. Aziz, N. S. A. Manan, M F Z KadirAbstract:Potato starch (PS)/graphene oxide (GO) blend–based solid polymer electrolyte has been doped with lithium trifluoromethanesulfonate (LiCF_3SO_3) via casting method. Lithium-based system is further infused with ionic liquid, 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) as a plasticizer to form a PS/GO/LiCF_3SO_3/[Bmim][Cl] electrolyte with improved conductivity characteristic. The ionic liquid–based polymer electrolyte PS/GO/LiCF_3SO_3/[Bmim][Cl] exhibits better physical properties based on structural characterisation and thermal analysis conducted. Values of linear sweep voltammetry (LSV) that evaluates the electrochemical potential window for salted and plasticized systems are 1.38 V and 1.92 V, respectively. Specific capacitance ( C _s) values calculated from charge–discharge measurement and cyclic voltammetry (CV) for the plasticized system are higher compared with those for the salted system. From the galvanostatic charge–discharge analysis, the value of C _s obtained for PS/GO/LiCF_3SO_3/[Bmim][Cl] is 37.9 F g^−1 at 0.6 mA cm^−2 current density. The results from CV and galvanostatic charge–discharge analysis confirm the suitability of PS/GO/LiCF_3SO_3 and PS/GO/LiCF_3SO_3/[Bmim][Cl] for electrochemical Double-Layer Capacitor (EDLC) application.
-
Electrochemical characteristics of solid state Double-Layer Capacitor constructed from proton conducting chitosan-based polymer blend electrolytes
Polymer Bulletin, 2020Co-Authors: Shujahadeen B. Aziz, M F Z Kadir, M. A. Brza, H. M. Hamsan, Rebar T. AbdulwahidAbstract:This research is about the preparation of polymer blend electrolytes based on chitosan using solution cast technique. Field emission scanning electron microscopy and Fourier transform infrared spectroscopy (FTIR) routes were utilized for studying morphological and structural properties, respectively. Electrical impedance spectroscopy (EIS) was engaged for determining the direct current electrical conductivity of the films. The ion association at the highest salt concentration was actually present as confirmed by EIS and FTIR achievements. The sample surface displays the protrude salts at the highest salt concentration. Proton conducting polymer electrolyte with NH_4Br as H^+ (proton) provider has been used in electric Double-Layer Capacitor (EDLC) applications. The highest conducting sample was used to fabricate EDLC. The transference number measurement indicated that the sample is mostly includes ion charge carriers which are vital for application in electrochemical devices. The linear sweep voltammetry study revealed that the decomposition of the sample takes place above 1.54 V. The fabricated EDLC device was performed capacitive behavior, as it can be seen from the cyclic voltammetry (CV) plot. Since no redox peaks have appeared, it can be concluded that the EDLC did not undergo either oxidation or reduction. The acquired value of specific capacitance (132.5 Fg^−1) is considered to be of great interest from the application viewpoints.
-
Study of impedance and solid-state Double-Layer Capacitor behavior of proton (H^+)-conducting polymer blend electrolyte-based CS:PS polymers
Ionics, 2020Co-Authors: Shujahadeen B. Aziz, M H Hamsan, M F Z Kadir, Rebar T. Abdulwahid, Wrya O. Karim, Ayub Sh. Marif, M. A. BrzaAbstract:A series of proton-conducting polymer blend electrolytes (PBEs) were prepared using solution casting techniques. Chitosan (CS) and starch of potato (PS) were blended and doped with various amounts of ammonium fluoride (NH_4F). The highest DC conductivity was found to be 1.38 × 10^−3 S/cm for the sample incorporated with 40 wt.% NH_4F salt using electrical impedance spectroscopy (EIS). A good complex formation between the polymer blends and the doped salt was confirmed from the morphology of the sample’s surface using field emission scanning electron microscope (FESEM). The crystalline peak broadening and intensity reduction of CS:PS polymer blend with the increasing salt concentration was observed in the X-ray diffraction (XRD) analysis. The type of charge carrier in the PBEs was examined via transference number measurements (TNM), and the dominancy of ion was approved. The extent of electrochemical stability of electrolyte was determined to be up to 1.78 V using linear sweep voltammetry (LSV). The specific capacitance of 6.85 F/g was obtained from cyclic voltammetry (CV) measurement. The rechargeability of the electric Double-Layer Capacitor (EDLC) exhibited stability up to 100 cycles with average specific capacitance of 4.1 F/g. Three criteria were determined, which are internal resistance, energy density, and power density (550 Ω, 0.57 Wh/kg, and 155 W/kg, respectively) of the EDLC at the first cycle.
-
Plasticized solid polymer electrolyte based on natural polymer blend incorporated with lithium perchlorate for electrical Double-Layer Capacitor fabrication
Ionics, 2019Co-Authors: Y. M. Yusof, K. Jumbri, M H Hamsan, M F Shukur, M F Z KadirAbstract:A plasticized solid polymer electrolyte system is prepared using polymer blend of methyl cellulose–potato starch with lithium perchlorate (LiClO_4) as dopant salt and glycerol as plasticizer. Transport properties of the electrolytes are investigated using electrical impedance spectroscopy (EIS). By applying a method proposed by Arof et al. which was found to be suitable for both Arrhenius and Vogel–Tammann–Fulcher (VTF) type of electrolytes, the number density ( n ), diffusion coefficient ( D ), and mobility ( μ ) of ions are found to be influenced by the concentration of glycerol. From ion and electron transference number analysis, it is verified that ions are the main charge carriers. Linear sweep voltammetry (LSV) verifies the suitability of the most conductive electrolyte to be employed in the carbon-based symmetric electrical Double-Layer Capacitor (EDLC) fabrication. The EDLC has been tested using the galvanostatic charge–discharge and cyclic voltammetry (CV) techniques. The specific capacitance ( C _sp) of the electrode using CV at a sweep rate of 2 mV s^−1 is found to be 61.58 F g^−1. The EDLC has been tested for 1000 charge–discharge cycles with the highest C _sp value of 28.04 F g^−1.
-
NH_4NO_3 as charge carrier contributor in glycerolized potato starch-methyl cellulose blend-based polymer electrolyte and the application in electrochemical Double-Layer Capacitor
Ionics, 2017Co-Authors: M H Hamsan, M F Shukur, M F Z KadirAbstract:Potato starch (PS)-methyl cellulose (MC) blend solid biopolymer electrolytes infused with ammonium nitrate (NH_4NO_3) and glycerol as plasticizer are made via the solution cast technique. Fourier transform infrared (FTIR) spectroscopy indicates that NH_4NO_3 has interacted with the polymer blend host. The addition of 40 wt% glycerol in the highest conducting plasticizer free electrolyte has improved the conductivity to the order of ∼10^−3 S cm^−1. The thermal stability of the electrolytes is identified by thermogravimetric analysis (TGA). Result from X-ray diffraction (XRD) analysis shows that the electrolyte with maximum conductivity value has the lowest degree of crystallinity. Differential scanning calorimetry (DSC) analysis reveals that the highest conducting plasticized electrolyte possesses the lowest glass transition temperature ( T _g) of −27.5 °C. Conductivity trend is further verified by dielectric analysis. Transference numbers of ion ( t _ion) and electron ( t _e) for the highest conducting electrolyte are identified to be 0.98 and 0.02, respectively, confirming that ions are the dominant charge carriers. Linear sweep voltammetry (LSV) evaluates that the potential window for the electrolyte is 1.88 V. The internal resistance of the electrochemical Double-Layer Capacitor (EDLC) is between 29 and 64 Ω. From the charged-discharged measurement, the value of C _s is 31 F g^−1. The EDLC is stable over 1000 cycles.
Xingjiang Liu - One of the best experts on this subject based on the ideXlab platform.
-
an electrochemical Double Layer Capacitor using an activated carbon electrode with gel electrolyte binder
Journal of The Electrochemical Society, 1999Co-Authors: Tetsuya Osaka, Xingjiang Liu, Masashi Nojima, Toshiyuki MommaAbstract:An electric Double Layer Capacitor (EDLC) was prepared with an activated carbon powder electrode with poly(vinylidene fluoridehexafluoropropylene) (PVdF-HFP) based gel electrolyte. Ethylene carbonate (EC) and propylene carbonate (PC) were used as plasticizer and tetraethylammonium tetrafluoroborate (TEABF4) was used as the supporting electrolyte. An optimized gel electrolyte of PVdF-HFP/PC/EC/TEABF4 5 23/31/35/11 mass ratio exhibited high ionic conductivity of 5 3 10 23 S cm 21 , high electrode capacitance, and good mechanical strength. An electrode consisting of activated carbon (AC) with the gel electrolyte as the bind er (AC/PVdF-HFP based gel, 7/3 mass ratio) showed a higher specific capacitance and a lower ion diffusion resistance within the electrode than a carbon electrode, prepared with PVdF-HFP binder without plasticizer. This suggests that an electrode mixed with the gel electrolyte has a lower ion diffusion resistance inside the electrode. The highest specific capacitance of 123 F g 21 was achieved with an electrode containing AC with a specific surface area of 2500 m 2 g 21 . A coin-type EDLC cell with optimized components showed excellent cycleability exceeding 10 4 cycles with ca. 100% coulombic efficiency achieved when charging and discharging was repeated between 1.0 and 2.5 V at 1.66 mA cm 22 .
-
all solid state electric Double Layer Capacitor with isotropic high density graphite electrode and polyethylene oxide liclo4 polymer electrolyte
Journal of The Electrochemical Society, 1996Co-Authors: Xingjiang Liu, Tetsuya OsakaAbstract:An isotropic high-density graphite was used as a polarizable electrode of all-solid state electric Double-Layer Capacitor using polyethylene oxide (PEO) or gel PEO electrolyte. The all-solid-state Capacitor with high-density graphite electrodes possesses higher differential capacity than the other flat electrodes in PEO/LiClO{sub 4} ([EO]/[Li{sup +}] = 8:1) solid polymer electrolyte at 80 C or PEO/PC/LiClO{sub 4} ([EO]/[PC]/[Li{sup +}] = 8:8:1) gel electrolyte at ambient temperature. The capacitance of the electric Double Layer of the high-density graphite electrode was strongly influenced by the cell temperature and concentration of LiClO{sub 4}, because of the different state of the polymer crystallinity and different interface contact state between the high-density graphite electrode and the solid electrolyte. The all-solid-state Capacitor with PEO/LiClO{sub 4} ([EO]/[Li{sup +}] = 8:1) solid polymer electrolyte and PEO/PC/LiClO{sub 4} ([EO]/[PC]/[Li{sup +}] = 8:8:1) gel electrolytes showed good charge/discharge behavior with a relatively high capacitance at 80 and 20 C, respectively.
Yoshikazu Nakayama - One of the best experts on this subject based on the ideXlab platform.
-
vertically aligned Double walled carbon nanotube electrode prepared by transfer methodology for electric Double Layer Capacitor
Journal of Power Sources, 2008Co-Authors: Yuichi Honda, Masayuki Takeshige, Hideki Shiozaki, Takaharu Kitamura, Kenji Yoshikawa, Supriya Chakrabarti, Osamu Suekane, Lujun Pan, Yoshikazu NakayamaAbstract:Abstract We successfully prepared a vertically aligned Double-walled carbon nanotube (DWCNT) sheet by a transfer procedure from a silicon substrate as a DWCNT seedbed that was covered with catalyst grains to an aluminum sheet as a current collector for application to a high-performance electrode for an electric Double Layer Capacitor (EDLC). The charge–discharge characteristics and EDLC performances of the aligned DWCNT electrode were evaluated and compared with those of a vertically aligned multi-walled CNT (MWCNT) electrode. The gravimetric capacitance of the DWCNT electrode was ca. four times larger than that of the MWCNT electrode. The rate capability of the DWCNT electrode was found to be excellent. This is mainly ascribed to our transfer technique.
C Sanjeeviraja - One of the best experts on this subject based on the ideXlab platform.
-
high performance solid state electric Double Layer Capacitor from redox mediated gel polymer electrolyte and renewable tamarind fruit shell derived porous carbon
ACS Applied Materials & Interfaces, 2013Co-Authors: S T Senthilkumar, Kalai R Selvan, Jose Savio Melo, C SanjeevirajaAbstract:The activated carbon was derived from tamarind fruit shell and utilized as electrodes in a solid state electrochemical Double Layer Capacitor (SSEDLC). The fabricated SSEDLC with PVA (polyvinyl alcohol)/H2SO4 gel electrolyte delivered high specific capacitance and energy density of 412 F g-1 and 9.166 W h kg-1, respectively, at 1.56 A g-1. Subsequently, Na2MoO4 (sodium molybdate) added PVA/H2SO4 gel electrolyte was also prepared and applied for SSEDLC, to improve the performance. Surprisingly, 57.2% of specific capacitance (648 F g-1) and of energy density (14.4 Wh kg-1) was increased while introducing Na2MoO4 as the redox mediator in PVA/H2SO4 gel electrolyte. This improved performance is owed to the redox reaction between Mo(VI)/Mo(V) and Mo(VI)/Mo(IV) redox couples in Na2MoO4/PVA/H2SO4 gel electrolyte. Similarly, the fabricated device shows the excellent capacitance retention of 93% for over 3000 cycles. The present work suggests that the Na2MoO4 added PVA/H2SO4 gel is a potential electrolyte to improv...