Entity

Time filter

Source Type

Stora Höga, Sweden

Raza R.,KTH Royal Institute of Technology | Raza R.,COMSATS Institute of Information Technology | Wang X.,KTH Royal Institute of Technology | Ma Y.,KTH Royal Institute of Technology | And 2 more authors.
Journal of Power Sources | Year: 2010

Calcium co-doped SDC-based nanocomposite electrolyte (Ce0.8Sm0.2-xCaxO2-δ-Na2CO3) was synthesized by a co-precipitation method. The microstructure and morphology of the composite electrolytes were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM), and thermal properties were determined with differential scanning calorimetry (DSC). The particle size, as shown by TEM imaging, was 5-20 nm, which is in a good agreement with the SEM and XRD results. The co-doping effect on both interfaces of the composite electrolyte and doped bulk effect inside the ceria was studied. The excellent performance of the fuel cell was about 1000 mW cm-2 at 560 °C and at the very low temperature of 350 °C the power density was 200 mW cm-2. This paper may give a new approach to develop functional nanocomposite electrolyte for low-temperature solid oxide fuel cell (LTSOFC). © 2010 Elsevier B.V. All rights reserved. Source


Raza R.,KTH Royal Institute of Technology | Raza R.,COMSATS Institute of Information Technology | Abbas G.,COMSATS Institute of Information Technology | Abbas G.,Bahauddin Zakaria University | And 4 more authors.
Solid State Ionics | Year: 2011

The purpose of this study is to develop new oxide ionic conductors based on nanocomposite materials for an advanced fuel cell (NANOCOFC) approach. The novel two phase nanocomposite oxide ionic conductors, Ce0.8Sm 0.2O2 - δ (SDC)-Y2O3 were synthesized by a co-precipitation method. The structure and morphology of the prepared electrolyte were investigated by means of X-ray diffraction (XRD) and high resolution scanning electron microscopy (HRSEM). XRD results showed a two phase composite consisting of yttrium oxide and samaria doped ceria and SEM results exhibited a nanostructure form of the sample. The yttrium oxide was used on the SDC as a second phase. The interface between two constituent phases and the ionic conductivities were studied with electrochemical impedance spectroscopy (EIS). An electrochemical study showed high oxide ion mobility and conductivity of the Y2O3-SDC two phase nanocomposite electrolytes at a low temperature (300-600 °C). Maximum conductivity (about 1.0 S cm-1) was obtained for the optimized Y2O 3-SDC composite electrolyte at 600 °C. It is found that the nanocomposite electrolytes show higher conductivities with the increased concentration of yttrium oxides but decreases after reaching a certain level. A high fuel cell performance, 0.75 W cm-2, was achieved at 580 °C. © 2010 Elsevier B.V. All rights reserved. Source


Raza R.,KTH Royal Institute of Technology | Raza R.,The University of Lahore | Wang X.,KTH Royal Institute of Technology | Ma Y.,KTH Royal Institute of Technology | And 2 more authors.
Journal of Power Sources | Year: 2010

We developed a new nickel-free anode for a low-temperature solid oxide fuel cell (LTSOFC) that demonstrated an outstanding electrochemical output of 1000 mW cm-2 at 550 °C. The nanostructure anode had good conductivity and was compatible with cerium oxide-based electrolytes. The performance of a single cell was comparable and or better than those using standard Ni-YSZ and Ni-SDC electrodes (anode). It may have applications for hydrocarbon-based fuel for preventing carbon deposition and replacing nickel in the anode of LTSOFCs. © 2010 Elsevier B.V. All rights reserved. Source


Mizuhata M.,Kobe University | Takeda K.,Kobe University | Raza R.,KTH Royal Institute of Technology | Wang X.,Kobe University | And 3 more authors.
EFC 2011 - Proceedings of the 4th European Fuel Cell Piero Lunghi Conference and Exhibition | Year: 2011

A ceria based oxide - carbonate, such as Ce-based oxide-(K0.50Na0.50)2CO3 was synthesized by a coprecipitation method as reported before. In order to investigate the coexisting effect of the solid phase and binary carbonates, the high temperature Raman spectroscopy measurements were carried out. In this paper, the detailed study shows that the observed remarkable temperature-dependent is primarily the result of softening/melting of the carbonate phase as the physical state of the carbonate phase transforms from solid, softened to molten. The possible coexistence of various charge carriers, oxide phase composition, and the oxide-carbonate interfacial area are envisaged was also studied by high temperature Raman spectroscopy. This study contributes to the understanding of the properties of nanocomposite ceria-carbonate electrolyte for low-temperature solid oxide fuel cells based on the NANOCOFC approach. Source


Raza R.,KTH Royal Institute of Technology | Raza R.,COMSATS Institute of Information Technology | Abbas G.,COMSATS Institute of Information Technology | Abbas G.,Bahauddin Zakaria University | And 4 more authors.
Journal of Nanoscience and Nanotechnology | Year: 2012

Nanocomposite based cathode materials compatible for low temperature solid oxide fuel cells (LTSOFCs) are being developed. In pursuit of compatible cathode, this research aims to synthesis and investigation nanocomposite La 0.3Sr 0.2Mn 0.1Zn 0.4 oxide-Sm 0.2Ce 0.8O1.9 (LSMZ-SDC) based system. The material was synthesized through wet chemical method and investigated for oxideceria composite based electrolyte LTSOFCs. Electrical property was studied by AC electrochemical impedance spectroscopy (EIS). The microstructure, thermal properties, and elemental analysis of the samples were characterized by TGA/DSC, XRD, SEM, respectively. The AC conductivity of cathode was obtained for 2.4 Scm ?1 at 550 °C in air. This cathode is compatible with ceria-based composite electrolytes and has improved the stability of the material in SOFC cathode environment. Copyright © 2012 American Scientific Publishers. All rights reserved. Source

Discover hidden collaborations