231 bhasker soni

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231 bhasker soni

  1. 1. Interdispersed YSZ-Zn doped CeO2-NiO-Ag Composites for Anode Supported Intermediate Temperature Solid Oxide Fuel Cells Bhasker Soni and Somnath Biswas* *Email: drsomnathbiswas@gmail.com Department of Physics, The LNM Institute of Information Technology (Deemed University) Jaipur – 302031, India 4th ICAER, IIT Bombay, 2013 1
  2. 2. Lecture Plan      Introduction Experimental details Results Future Work Conclusions 4th ICAER, IIT Bombay, 2013 2
  3. 3. Introduction  Global energy requirements are increasing rapidly  Energy crisis  Green house effect  Global warming  Limited energy sources : Conventional and non-conventional  Drawbacks with the present power technologies  Lack of efficient technology Fuel cells technology 4th ICAER, IIT Bombay, 2013 3
  4. 4. Introduction 4th ICAER, IIT Bombay, 2013 4
  5. 5. Introduction 4th ICAER, IIT Bombay, 2013 5
  6. 6. Introduction Presently used technology 4th ICAER, IIT Bombay, 2013 6
  7. 7. Introduction  Fuel cell : An electrochemical device that converts energy produced from a chemical reaction into electrical energy. This chemical reaction is not a combustion process  Chemical Energy  Electrical Energy Working : Anode: 2H2 + 2O= =4e- + 2H2O Cathode: O2 + 4e- = 2O= Over All: 2H2 + O2 = 2H2O Electricity is generated with H2O as byproduct.   Animation taken from Solid state energy conversion Alliance (SECA) 4th ICAER, IIT Bombay, 2013 7
  8. 8. Introduction Types of Fuel Cells       PEMFC (proton exchange membrane) DMFC (direct methanol) AFC (alkaline) PAFC (phosphoric acid) MCFC (Molten Carbonate) SOFC (solid oxide) 4th ICAER, IIT Bombay, 2013 8
  9. 9. Introduction    SOFC : Solid Oxide Fuel Cell. Working : Anode: 2H2 + 2O= =4e- + 2H2O Cathode: O2 + 4e- = 2O= Over All: 2H2 + O2 = 2H2O Electricity is generated with H2O as byproduct. 4th ICAER, IIT Bombay, 2013 9
  10. 10. Advantages  High conversion efficiency 45%(up to *85% energy efficiency when combined with gas turbine).  Combined heat and power.  No need for electrolyte management.  Ample fuel flexibility (Nat. gas/methane fuelled).  Non Polluting - no NOx/SOx  Long life, modular.  Quiet in operation.  Load flexible.  Low cost ceramic and non noble metal materials. SOFCs 10
  11. 11. Disadvantages  High operating temperature (800 °C – 1000 °C).  Less material selection options. Thermal stress.  Degradation and delamination.  Long start up time.  Difficulty in stacking cells. 4th ICAER, IIT Bombay, 2013 11
  12. 12. Experimental Details Synthesis  Synthesis of nanoparticles  Synthesis of YSZ-CZO-NiO-Ag nanocomposites. 4th ICAER, IIT Bombay, 2013 12
  13. 13. Experimental Details Synthesis of nanoparticles of 8YSZ, Ni:NiO, Zn doped CeO2(CZO)  Sol-gel type chemical precursor Nitrate solutions of method.  Y(NO3)3·6H2O  pH: Basic medium  ZrO(NO3)2·H2O  Ni(NO3)2.6H2O  Reaction Temperature: 60 – 70 C C  Ce(NO3)3·6H2O  Zn(NO3)3·6H2O  Amorphous dried precursor.  Calcined at 400 C,500 C and 600 C. Magnetic Stirrer 4th ICAER, IIT Bombay, 2013 13
  14. 14. Experimental Details 40 50 (331) (420) (222) (400) 80 50 70 80  60 Diffraction Angle, 2 (degree)  70  (222)  NiO  Ni  40 (400) 60 (311) (220) (111)   30 (311) 50 (200) (c) 20 70 (220) 40 (200) 30 (111) 20 60 (220) (200) (b) 30 (111) Intensity (arb. unit) 20 (311) (220) (200) (a) (111) Synthesis of nanoparticles of 8YSZ, Ni:NiO, Zn doped CeO2(CZO)  80 Fig. 1 XRD plots of (a) 10 mol% CZO, (b) 8 mol% YSZ, and (c) Ni : NiO (core-shell) nanoparticles obtained after heat treatment of the corresponding precursors at 400°C, 500°C and 600°C, respectively in ambient air. 4th ICAER, IIT Bombay, 2013 14
  15. 15. Experimental Details (a) (b) (c) (d) Fig. 2 Typical HRTEM images of (a, b) 8 mol% YSZ, (c) 10 mol% CZO, and (d) Ni:NiO nanoparticles. 4th ICAER, IIT Bombay, 2013 15
  16. 16. Experimental Details Synthesis of nanoparticles of 8YSZ, Ni:NiO, Zn doped CeO2(CZO) (a) (b) Fig. 3 FESEM images of (a) 10 mol% CZO and (b) 8 mol% YSZ nanoparticles. 4th ICAER, IIT Bombay, 2013 16
  17. 17. Experimental Details Synthesis of YSZ-CZO-NiO-Ag nanocomposites Structural Electrical Sample Code YSZ (vol%) CZO (vol%) Ni : NiO (vol%) A 20 20 60 B 25 25 50 C 30 30 40 D 35 35 30  Series of composite samples.  Ball milled for 5 h.  Starch as pore former.  Ball to Powder ratio 10 : 1. Table 1. Compositional details of YSZ-CZO-Ni:NiO composites. 4th ICAER, IIT Bombay, 2013 17
  18. 18. Experimental Details Synthesis of YSZ-CZO-NiO-Ag nanocomposites Structural Electrical Sample Code YSZ (vol%) CZO (vol%) Ni : NiO (vol%) A 20 20 60 B 25 25 50 C 30 30 40 D 35 35 30  TEC of YSZ : 10.5 x10-6 K-1.  TEC of Ni : 13.0 x10-6 K-1.  TEC of CeO2 : 12.58 x10-6 K-1 TEC of Ag : 18.0 x10-6 K-1. Table 1. Compositional details of YSZ-CZO-Ni:NiO composites. 4th ICAER, IIT Bombay, 2013 18
  19. 19. Experimental Details (200) (111)  CZO  YSZ  NiO Ni     (220) (311) (220) (222) • (311)  (311) • (220) (220) (200) (200) (200) Intensity (arb. unit) (A) (111) (111) •      •  (B) (C) (D) 20 30 40 50 60 70 80 Diffraction Angle, 2 (degree) Fig. 4 XRD plots of YSZ-CZO-Ni:NiO nanocomposites of compositions as shown in Table 1. 4th ICAER, IIT Bombay, 2013 19
  20. 20. Experimental Details  Porosity measurement using ASTM C20 technique  Sample is oven dried at 110 ⁰ C till constant weight is achieved.  Submerged in boiling water for 4 h.  When suspended in water, the weight is measured to calculate specific gravity.  Porosity (P,%) = (W – D)/V x 100 = 38.4% (sample A) = 38.7% (sample C) where, W = saturated weight D = dry weight V = volume of sample 4th ICAER, IIT Bombay, 2013 20
  21. 21. Future Work  Oxygen Permeability.  Impedance Spectroscopy.  I-V and I-P characteristics : DC Four Probe.  Mechanical properties : Ductility and strength, Elastic properties, CTE, Poisson's ratio, creep analysis etc. 4th ICAER, IIT Bombay, 2013 21
  22. 22. Conclusions  Composite anode materials of YSZ-CZO-Ni:NiO for intermediate temperature SOFCs have been developed by mechanical attrition method.  From XRD studies, the crystal structure of YSZ, CZO and Ni:NiO has been confirmed to be cubic in nature.  FESEM and HRTEM micrographs reveal the fine structure of the particles.  Electrical and electro-chemical analyses of the samples are currently being performed.  Successful development of this material would decrease the polarization losses at anode and aid in enhancing the cell performance at lower temperatures. 4th ICAER, IIT Bombay, 2013 22
  23. 23. Acknowledgements The authors sincerely thank (i) Tata Institute of Fundamental Research (TIFR), Mumbai (ii) UGC-DAE Consortium for Scientific Research, Indore, (iii) Sathyabama University, Chennai, and (iv) Sophisticated Analytical Instrument Facility (SAIF), North-Eastern Hill University (NEHU), Shillong for providing us the instrumental facilities. We also thank The LNM Institute of Information Technology for their financial support to carry out the research work. 4th ICAER, IIT Bombay, 2013 23
  24. 24. THANK YOU 24

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