To investigate the Effect of Alkaline Earth Metals on Electrochemical Activities of Lanthanum Cobalt Zinc Oxide Cathode Materials

Abstract

In the modern age of science and technology every system of manual work is transferring to machines and to run these machines energy is required, so the need of time is motivating researchers to enhance their activities in the scope of renewable energy production devices which will be able to produce more energy at very low cost. In this regard fuel cell got higher attraction of investigation due to its higher efficiency, environmentally friendly nature, and low cost. Solid oxide fuel cell (SOFC) is an extremely encouraging class of fuel cells. SOFC consists of electrolyte sandwiched between anode and cathode. In this research work, lanthanam-based cobalt Zinc oxide cathode materials are prepared by sol-gel route alongwith the characterizions for the cathode functioning of solid oxide fuel cell (SOFC). FTIR technique is employed to analyse the chemical composition and its bounding. In BaLaCoZn peaks are found at 853 cm -1 ,859 cm -1 and 1426 cm -1 which are corresponding to C-O, La-O and Co-O respectively. In CaLaCoZn peaks are found at 703 cm -1 , 988 cm -1 , 1433 cm -1 which are attributed to Zn-O, C-O,Co-O, respectively. In SrLaCoZn peaks are observed at 856 cm -1 , 950 and 1441 cm -1 which belong to Sr-O, Zn-O respectively. For Sr1Co0.8La0.2 (SCL) peaks are found at 157 cm -1 , 525 cm -1 , 957 cm -1 and 1363 cm -1 . The analysis of existence of each and every C-H, C-C, C=C, O-H either of bending or stretching nature is given in following table against each wave number in each sample. In infrared spectroscopy, there are basically two regions, fingerprint region and functional groups region. The range of fingerprint region is from 400 cm -1 to 1500 cm -1 wave number which is not analyzed usually due to its complexity, as a large number of peaks appears in that region. Each bond represents existence of a functional groups. The prepared cathodes have strong peaks in the range of 700 cm -1 to 1800 cm -1 .The peaks are attributed to C-H, C=O, O-H and C=C which are the main bonds present in oxides base cathodes. Raman spectroscopy is used to detect vibrational, rotational, and other states in a molecular system, capable of probing the chemical composition of materials. For samples BLCZ (S1) peaks are found at 157, 525, 957 and 1363 cm -1 . The peaks at 157 and 525 cm −1 wavelengths are analogous to O-B-O typical vibrations. The peak at 957 cm −1 wavelength correspond to B-O bonds stretching vibrations. For samples SLCZ (S3) peaks are found at 141, 296,649, 939, 1086 and 1344 cm -1 . The peaks at 141, 296 and 649 cm −1 wavelengths are analogous to O-B-O typical vibrations. The peaks at 939 and 1086 cm −1 wavelength correspond to B-O bonds stretching vibrations. Furthermore, for the Raman spectra of single Perovskite LSCF there is no mode vibrations in the range of 200–500 and 700–900 cm −1 can be found except (S2), which are xi demonstrative of double Perovskite structures LSCF materials. Therefore, the outcomes of the Raman spectral study agree well with those of literature, which showed that both the rhombohedra structure and double Perovskite phase are from space group R3C. So S1, S2 and S3 will behaves as an excellent cathode material as generating more oxygen ion vacancies which enhance the oxygen reduction reaction (ORR) at the cathode side. The electrical DC conductivity of prepared cathodes BaLaCoZn, CaLaCoZn and SrLaCoZn were measured by two probe method in the temperature range of (300-600) o C in the presence of methane as a fuel in air environment. The synthesized cathode material (S1) has maximum conductivity of 10.12 Scm -1 at 600 °C and the synthesized cathode material (S2) has minimum value of 3.3 Scm -1 at 300 °C.