Faculty Publications
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Item Studies on the Solid Oxide Cell Perovskite Electrode Materials for Soot Oxidation Activity(Springer, 2019) Shenoy, C.S.; Patil, S.S.; Govardhan, P.; Shourya, A.; Prasad Dasari, H.P.; Saidutta, M.B.; Harshini, H.Solid oxide cell (SOC) perovskite electrode materials (BSCF (Ba0.5Sr0.5Co0.8Fe0.2O3-?), LSCF (La0.6Sr0.4Co0.2Fe0.8O3-?) and LSCM (La0.75Sr0.25Cr0.5Mn0.5O3-?)) were synthesised using microwave-assisted reverse-strike co-precipitation method and tested for soot oxidation activity. The calcined perovskite materials were characterized using FT-IR, XRD, SEM and BSE, BET and BJH and XPS analysis. The mean activation energy for soot oxidation was calculated from Ozawa plots at various heating rates (5, 10, 15 and 20 K/min) at different levels of soot conversions (T10 to T90) for BSCF, LSCM and LSCF perovskite materials and was around 133 ± 11.5, 138 ± 9.9 and 152 ± 7.2 kJ/mol, respectively. Irrespective of the heating rates, BSCF material showed the lowest T50 temperature than compared to other samples, and it is correlated to the presence of Fe3O4 as a secondary phase. © 2019, Springer Nature Switzerland AG.Item Dilatometer studies on LAMOX based electrolyte materials for solid oxide fuel cells(Elsevier Ltd, 2021) Das, A.; Lakhanlal, u.; Shajahan, I.; Prasad Dasari, H.P.; Saidutta, M.B.; Harshini, H.The present study deals with the citrate complexion synthesis of LAMOX-based Solid Oxide Fuel Cell (SOFC) electrolyte materials (La1.8Dy0.2Mo2-xWxO9 (x = 0, 0.1, 0.2, 0.5, and 1), La1.8Dy0.2Mo2-xGaxO9 (x = 0.1 and 0.2), and La1.8Dy0.2Mo2-xVxO9 (x = 0.025, 0.05, 0.1, and 0.2)) and their characterization to understand the sintering behaviour and phase stability. From the dilatometer studies, the linear shrinkage and shrinkage rate of the LDMW (x = 0, and 0.1) showed better shrinkage than LM and LDM. Gallium addition (LDMG) and Vanadium addition (LDMV) showed a negative impact on shrinkage behaviour. In the temperature range of 500–580 °C, the abrupt change in shrinkage rate showed the transition of phase from ? to ? for the LM. The modification of LM to LDM, LDMW, and LDMV suppressed the formation of the ? phase. During thermal expansion behaviour study in the temperature range of 100–500 °C and 550–800 °C, the LM sintered pellet showed the coefficient of thermal expansion (CTE) values of 13.3 ? 10?6/°C and 21.6 ? 10?6/°C respectively. The LDM and LDMW sintered pellets showed the CTE values in the range of 14–15 ? 10?6/°C and 16–19 ? 10?6/°C, respectively. The relative density of the sintered pellets (1100 °C/5 h in air) (LM, LDM, LDMW, and LDMG (x = 0.1)) is found to be >90%. It provides the suitability of these materials for further investigation as electrolytes of SOFCs/SOECs. © 2020 Elsevier B.V.Item Electrical conductivity studies on LAMOX based electrolyte materials for solid oxide fuel cells(Elsevier Ltd, 2022) Srijith; Lakhanlal, u.; Das, A.; Prasad Dasari, H.P.; Saidutta, M.B.In this study, the electrical conductivity of the LAMOX based electrolytes (La1.8Dy0.2Mo2-xWxO9 (x = 0, 0.1, 0.2, 0.5, and 1), and La1.8Dy0.2Mo2-xGaxO9 (x = 0.1)) synthesized by the citrate complexion method has been studied using DC four-probe method. The electrical conductivity of the electrolytes is measured in the temperature range of 800–400 °C in the air (∼100 ml min−1). The effect of W and Ga substitution at the Mo site on the electrical conductivity is evaluated. The long-term electrical conductivity stability test (time on stream) (5 h) is conducted at 650, 580, and 520 °C to study the effect of possible phase transition on electrical conductivity. A high-temperature XRD study is also conducted in the temperature range of 500–650 °C (during heating and cooling) on selected electrolyte materials (La1.8Dy0.2Mo2-xWxO9 (x = 0 and 0.1) and La1.8Dy0.2Mo2-xGaxO9 (x = 0.1)) to study the α↔β phase transition. The electrical conductivity of these electrolytes in the air at 800 °C is in the range of 5.3 × 10−2 – 14 × 10−2 S cm−1. The activation energy (EA) of these electrolytes is in the range of 1.11–1.62 eV. The VTF parameters σo, B, and To are in the range of 67.46–395.88 S cm−1 K0.5, 0.122–0.254 eV, and 247–347 °C, respectively. The La1.8Dy0.2Mo2-xWxO9 (x = 0.1) shows highest electrical conductivity (14 × 10−2 S cm−1, EA = 1.54 eV) among all electrolytes in air at 800 °C and for this material the VTF parameters σo, B, and To are 170.32 S cm−1 K0.5, 0.153 eV, and 302 °C, respectively. © 2022 Elsevier Ltd and Techna Group S.r.l.