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Item Open Access Carbon Formation on Stainless Steel 304H in the Convection Section of an Ethane Cracking Plant(Taylor & Francis, 2015) Ramezanipour, Farshid; Singh, Anand; Paulson, Scott; Farag, Hany; Birss, Viola; Thangadurai, VenkataramanItem Open Access Chemically Stable Proton Conducting Doped BaCeO3 -No More Fear to SOFC Wastes(Springer Science and Business Media LLC, 2013-07-04) Kannan, Ramaiyan; Singh, Kalpana; Gill, Sukhdeep; Fürstenhaupt, Tobias; Thangadurai, VenkataramanDevelopment of chemically stable proton conductors for solid oxide fuel cells (SOFCs) will solve several issues, including cost associated with expensive inter-connectors and long-term durability. Best known Y-doped BaCeO3 (YBC) proton conductors-based SOFCs suffer from chemical stability under SOFC by-products including CO2 and H2O. Here, for the first time, we report novel perovskite-type Ba0.5Sr0.5Ce0.6Zr0.2Gd0.1Y0.1O3?? by substituting Sr for Ba and co-substituting Gd + Zr for Ce in YBC that showed excellent chemical stability under SOFC by-products (e.g., CO2 and H2O) and retained a high proton conductivity, key properties which were lacking since the discovery of YBCs. In situ and ex- situ powder X-ray diffraction and thermo-gravimetric analysis demonstrate superior structural stability of investigated perovskite under SOFC by-products. The electrical measurements reveal pure proton conductivity, as confirmed by an open circuit potential of 1.15?V for H2-air cell at 700°C and merits as electrolyte for H-SOFCs.Item Open Access Comparative Evaluation of Coated and Non-Coated Carbon Electrodes in a Microbial Fuel Cell for Treatment of Municipal Sludge(MDPI AG, 2019-03-16) Nandy, Arpita; Sharma, Mohita; Venkatesan, Senthil Velan; Taylor, Nicole; Gieg, Lisa; Thangadurai, VenkataramanThis study aims to provide insight into the cost-effective catalyst on power generation in a microbial fuel cell (MFC) for treatment of municipal sludge. Power production from MFCs with carbon, Fe2O3, and Pt electrodes were compared. The MFC with no coating on carbon generated the least power density (6.72 mW·m?2) while the MFC with Fe2O3-coating on carbon anodes and carbon cathodes generated a 78% higher power output (30.18 mW·m?2). The third MFC with Fe2O3-coated carbon anodes and Pt on carbon as the cathode catalyst generated the highest power density (73.16 mW·m?2) at room temperature. Although the power generated with a conventional Pt catalyst was more than two-fold higher than Fe2O3, this study suggests that Fe2O3 can be investigated further as an efficient, low-cost, and alternative catalyst of Pt, which can be optimized for improving performance of MFCs. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) results demonstrated reduced resistance of MFCs and better charge transfer between biofilm and electrodes containing coated anodes compared to non-coated anodes. Scanning electron microscopy (SEM) was used to analyze biofilm morphology and microbial community analysis was performed using 16S rRNA gene sequencing, which revealed the presence of known anaerobic fermenters and methanogens that may play a key role in energy generation in the MFCs.Item Open Access Conjugated main-group polymers for optoelectronics(Royal Society of Chemistry, 2013-08-07) He, Xiaoming; Baumgartner, ThomasThe last decade has witnessed great progress in conjugated polymers for application in optoelectronics. The biggest driving force for the field is to develop polymers with suitable HOMO and LUMO orbital energies, as well as high charge carrier mobility for improved performance in practical devices. Apart from the conventional donor–acceptor (D–A) strategy to tune the optoelectronic properties, the incorporation of main-group elements represents a promising new way to achieve a similar function, however, more efficiently, due to the intrinsic electronic properties of the main-group components. This review highlights the recent advances in main-group element-based conjugated polymers for application in optoelectronics, representatively focusing on Se-, Te-, P-, Si-, Ge-, and B-containing materials.Item Open Access Correction: Synthesis and characterization of novel Li-stuffed garnet-like Li5+2xLa3Ta2?xGdxO12 (0 ? x ? 0.55): structure–property relationships(Royal Society of Chemistry (RSC), 2017-06-15) Basset, Dalia M. Abdel; Mulmi, Suresh; E-Bana, Mohammed S.; Fouad, Suzan S.; Thangadurai, VenkataramanCorrection for ‘Synthesis and characterization of novel Li-stuffed garnet-like Li5+2xLa3Ta2?xGdxO12 (0 ? x ? 0.55): structure–property relationships’ by Dalia M. Abdel Basset, et al., Dalton Trans., 2017, 46, 933–946.Item Open Access Dielectric characteristics of fast Li ion conducting garnet-type Li5+2xLa3Nb2 xYxO12 (x = 0.25, 0.5 and 0.75)(Royal Society of Chemistry, 2016) Narayanan, Sumaletha; Baral, Ashok Kumar; Thangadurai, VenkataramanHere, we report the dielectric characteristics of Li-stuffed garnet-type Li5+2xLa3Nb2−xYxO12 (x = 0.25, 0.5 and 0.75) in the temperature range about −53 to 50 °C using AC impedance spectroscopy. All the investigated Li-stuffed garnet compounds were prepared, under the same condition, using conventional solid-state reaction at elevated temperature in air. The Nyquist plots show mainly bulk contribution to the total Li+ ion conductivity for Li5.5La3Nb1.75Y0.25O12 (Li5.5–Nb) and Li6La3Nb1.5Y0.5O12 (Li6–Nb), while both bulk and grain-boundary effects are visible in the case of Li6.5La3Nb1.25Y0.75O12 (Li6.5–Nb) phase at ∼−22 °C. Non-Debye relaxation process was observed in the modulus AC impedance plots. The dielectric loss tangent of Li5+2xLa3Nb2−xYxO12 are compared with that of the corresponding Ta analogue, Li5+2xLa3Ta2−xYxO12 and showed a decrease in peak intensity for the Nb-based garnet samples which may be attributed to a slight increase in their Li+ ion conductivity. The relative dielectric constant values were also found to be higher for the Ta member (>60 for Li5+2xLa3Ta2−xYxO12) than that of the corresponding Nb analogue (∼50 for Li5+2xLa3Nb2−xYxO12) at below room temperature. A long-range order Li+ ion migration pathway with relaxation time (τ0) 10−18–10−15 s and an activation energy of 0.59–0.40 eV was observed for the investigated Li5+2xLa3Nb2−xYxO12 garnets and is comparable to that of the corresponding Ta-based Li5+2xLa3Ta2−xYxO12 garnets.Item Open Access Dopant Concentration - Porosity - Li-ion Conductivity Relationship in Garnet-Type Li5+2xLa3Ta2-xYxO12 (0.05 ≤ x ≤ 0.75) and Their Stability in Water and 1M LiCl(American Chemical Society, 2015) Narayanan, Sumaletha; Ramezanipour, Farshid; Thangadurai, VenkataramanItem Open Access Effect of Excess Li on the Structural and Electrical Properties of Garnet-Type Li6La3Ta1.5Y0.5O12(Electrochemical Society, 2015) Narayanan, Sumaletha; Hitz, Gregory T.; Wachsman, Eric D.; Thangadurai, VenkataramanVolatility of lithium during preparation of lithium-stuffed garnet-type metal oxide solid Li ion electrolytes is a common problem, which affects phase formation, ionic conductivity, mechanical strength and density. Synthesis of Li-stuffed garnets has been performed generally using the conventional solid-state reactions at elevated temperature in air. The present study describes the effect of excess LiNO3 (2.5 to 15 wt.%) addition during the ceramic synthesis on the structural and electrical properties of garnet-type Li6La3Ta1.5Y0.5O12. Powder X-ray diffraction (PXRD) confirmed that cubic phase was formed in all tested cases, and there is no significant variation in lattice parameter with amount of excess LiNO3 used. However, increasing amounts of excess lithium decreased inter-particle contact and increased grain growth during sintering, producing sharply varied microstructures. PXRD showed no secondary phase and scanning electron microscopy (SEM) analysis showed rather uniform morphology and absence of "glassy" materials at the grain-boundaries. The bulk Li ion conductivity was found to increase with amount of excess lithium, reaching a maximum room temperature conductivity of 1.62 × 10−4 Scm−1 for the sample prepared using 10 wt.% excess LiNO3. Raman microscopy study indicated the presence of Li2CO3 in all aged Li6La3Ta1.5Y0.5O12 samples prepared using excess LiNO3.Item Open Access Effect of sintering temperature on microstructure, chemical stability, and electrical properties of transition metal or Yb-doped BaZr0.1Ce0.7Y0.1M0.1O3?? (M = Fe, Ni, Co, and Yb)(Frontiers Media SA, 2014-03-13) Mirfakhraie, Behzad; Ramezanipour, Farshid; Paulson, Scott; Virss, Viola; Thangadurai, VenkataramanPerovskite-type BaZr0.1Ce0.7Y0.1M0.1O3?? (M = Fe, Ni, Co, and Yb) (BZCY-M) oxides were synthesized using the conventional solid-state reaction method at 1350–1550°C in air in order to investigate the effect of dopants on sintering, crystal structure, chemical stability under CO2 and H2S, and electrical transport properties. The formation of the single-phase perovskite-type structure with an orthorhombic space group Imam was confirmed by Rietveld refinement using powder X-ray diffraction for the Fe, Co, Ni, and Yb-doped samples. The BZCY-Co and BZCY-Ni oxides show a total electrical conductivity of 0.01 and 8 × 10?3 S cm?1 at 600°C in wet H2 with an activation energy of 0.36 and 0.41 eV, respectively. Scanning electron microscope and energy-dispersive X-ray analysis revealed Ba and Co-rich secondary phase at the grain-boundaries, which may explain the enhancement in the total conductivity of the BZCY-Co. However, ex-solution of Ni at higher sintering temperatures, especially at 1550°C, decreases the total conductivity of the BZCY-Ni material. The Co and Ni dopants act as a sintering aid and form dense pellets at a lower sintering temperature of 1250°C. The Fe, Co, and Ni-doped BZCY-M samples synthesized at 1350°C show stability in 30 ppm H2S/H2 at 800°C, and increasing the firing temperature to 1550°C, enhanced the chemical stability in CO2/N2 (1:2) at 25–900°C. The BZCY-Co and BZCY-Ni compounds with high conductivity in wet H2 could be considered as possible anodes for intermediate temperature solid oxide fuel cells.Item Open Access Effect of V-doping on the structure and conductivity of garnet-type Li5La3Nb2O12(Springer, 2015) Kan, Wang Hay; Truong, Lina; Thangadurai, VenkataramanItem Open Access Electrochemical Studies of Gd0.5Pr0.5BaCo2O5+δ (GPBC) Cathode for Oxide Ion and Proton Conducting Solid Oxide Fuel Cells(Elsevier, 2016) Singh, Kalpana; Baral, Ashok K.; Thangadurai, VenkataramanItem Open Access Electrolyte selection for supercapacitive devices: a critical review(Royal Society of Chemistry (RSC), 2019-08-27) Pal, Bhupender; Yang, Shengyuan; Ramesh, Subramaniam; Thangadurai, Venkataraman; Jose, RajanElectrolytes are one of the vital constituents of electrochemical energy storage devices and their physical and chemical properties play an important role in these devices' performance, including capacity, power density, rate performance, cyclability and safety. This article reviews the current state of understanding of the electrode–electrolyte interaction in supercapacitors and battery–supercapacitor hybrid devices. The article discusses factors that affect the overall performance of the devices such as the ionic conductivity, mobility, diffusion coefficient, radius of bare and hydrated spheres, ion solvation, viscosity, dielectric constant, electrochemical stability, thermal stability and dispersion interaction. The requirements needed to design better electrolytes and the challenges that still need to be addressed for building better supercapacitive devices for the competitive energy storage market have also been highlighted.Item Open Access Evaluation of MIEC Ce0.8Y0.1Mn0.1O2-δ Anode in Electrolyte-Supported SOFC(Electrochemical Society, 2016) Handal, Hala T.; Addo, Paul; Buyukaksoy, Aligul; Birss, Viola; Thangadurai, VenkataramanItem Open Access Evaluation on the Effect of Gd-doping for Nb on the Morphology and Ionic Conductivity of Garnet-like Li5La3Nb2O12(NRC Research Press, 2016) Pinzaru, Dana; Thangadurai, VenkataramanItem Open Access Fast Solid State Li ion Conducting Garnet-Type Structure Metal Oxides for Energy Storage(American Chemical Society, 2015) Thangadurai, Venkataraman; Pinzaru, Dana; Narayanan, Sumaletha; Baral, Ashok K.Item Open Access Grain Boundary Space Charge Effect and Proton Dynamics in Chemically Stable Perovskite-type Ba0.5Sr0.5Ce0.6Zr0.2Gd0.1Y0.1O3-δ (BSCZGY): A Case Study on Effect of Sintering Temperature(Wiley, 2016) Singh, Kalpana; Baral, Ashok K.; Thangadurai, VenkataramanItem Open Access High Performance Tubular Solid Oxide Fuel Cell Based on Ba0.5Sr0.5Ce0.6Zr0.2Gd0.1Y0.1O3-? Proton Conducting Electrolyte(The Electrochemical Society, 2018-07-07) Amiri, Taghi; Singh, Kalpana; Sandhu, Navjot Kaur; Hanifi, Amir Reza; Etsell, Thomas H.; Luo, Jing-Li; Thangadurai, Venkataraman; Sarkar, ParthaIn this work, synthesis and characterization of an anode supported tubular solid oxide fuel cell based on Ba0.5Sr0.5Ce0.6Zr0.2Gd0.1Y0.1O3-? (BSCZGY) electrolyte has been investigated. Anode-supported Ni - yttria-stabilized zirconia (YSZ) anode was fabricated via slip casting; BSCZGY electrolyte and BSCZGY - La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) composite cathode were coated on support using dip coating, respectively. The chemical compatibility of fuel cell components at sintering temperatures has been investigated by powder X-ray diffraction, and no severe reactions were detected. Electrochemical examination under air/H2 + 3 vol. % H2O showed superior performance achieving a maximum power density of 1 W/cm2 at 850°C, among the best compared to tubular – geometry oxygen conductor solid oxide fuel cells reported earlier and one of the highest reported for a proton conductor electrolyte in literature. Electrochemical impedance spectroscopy was used to examine the electrochemical performance of the full cell at different temperatures, and a detailed analysis was done to distinguish the contribution of ohmic and polarization resistances of the cell. ASR values were 3.47 ?.cm2, 1.81 ?.cm2, 1.23 ?.cm2, and 1.05 ?.cm2 at 600, 700, 800, and 850°C, respectively. Analysis of activation energy associated with charge and mass transfer based on fitting of impedances revealed that concentration polarization is the major contributor to the total resistance. The long-term stability for more than 96 hours of operation under load showed no significant degradation, which demonstrated the steady behavior of the cell.Item Open Access Higher Conductivity Li-Garnets by a Multi-Element Doping Strategy(American Chemical Society, 2015) Tong, Xia; Thangadurai, Venkataraman; Wachsman, EricItem Open Access Hybrid Gel Electrolytes Derived From Keggin-type Polyoxometalates (POMs) and N-Methyl Imidazolium 1-(3-Sulfonic Group) Propyl (MIMPS) Ionic Liquid with Enhanced Electrochemical Stability and Fast Ionic Conductivity(American Chemical Society, 2015) Tong, Xia; Thangadurai, VenkataramanItem Open Access Ni-Ba0.5Sr0.5Ce0.6Zr0.2Gd0.1Y0.1O3-Delta Anode Composites for Proton Conducting Solid Oxide Fuel Cells (H-SOFCs)(Canadian Center of Science and Education, 2016-09-01) Singh, Kalpana; Baral, Ashok Kumar; Thangadurai, VenkataramanIn this paper, we report the electrochemical properties of Ni-Ba0.5Sr0.5Ce0.6Zr0.2Gd0.1Y0.1O3-Delta (BSCZGY) anode composites in 3% H2O-H2 for proton conducting solid oxide fuel cells (H-SOFCs). Ni-BSCZGY composites with volume ratio of 30:70, 40:60, and 50:50 were synthesised through mechanical mixing and combustion methods. In combustion method, auto-ignition step led to brown coloured ash, which was calcined at 1000 oC for 5 h to form NiO-BSCZGY powder. Screen-printing, co-firing and reduction process were used to prepare the symmetrical cell: Ni-BSCZGY/BSCZGY/Ni-BSCZGY. Ni50-BSCZGY anode exhibited the lowest polarisation resistance (Rp) of 0.8 Omega.cm2 and 1.9 Omega.cm2 at 710 oC under 3% H2O-H2, for both mechanically mixed and combustion methods, respectively.