Preparation of composite cathode material by using the extracted lead (Pb) of waste lead acid battery for LT-SOFC

Abstract

The extraction of Pb from the waste lead acid batteries offers the conservation of energy resources and reduction of pollution load in the environment. The recycling of waste lead acid batteries than discarding by conventional methods is the best way. In the present studies, for LT-SOFC, three composite cathode materials (Pb0.1Fe0.4Co0.5O4-δ, Pb0.2Fe0.3Co0.5O4-δ and Pb0.3Fe0.2Co0.5O4-δ) were produced by extracting Pb from the waste lead acid batteries, cobalt nitrate [Co(NO3)3.6H2O] and iron nitrate [Fe(NO3)3.9H2O] using standard solid state reaction method. Thermal stability, morphological and structural characteristics were studied by TGA, SEM and XRD analyses. FTIR spectra were used to investigate the types of metal oxide bonding in the prepared ceramic composite cathode materials. Fuel cell testing and DC four probes were used to investigate electrochemical properties. The measurement of average crystalline size of the composites was found to be in the range of 12–37 nm.Scanning electron microscopy (SEM) images showed that composite materials are porous and suitable to diffuse the gases. The maximum conductivities of 1.6 Scm−1, 2.05 Scm−1 and 2.6 Scm−1 have been obtained for Pb0.1Fe0.4Co0.5O4-δ, Pb0.2Fe0.3Co0.5O4-δ and Pb0.3Fe0.2Co0.5O4-δ, respectively. At 600 °C, the high OCV (0.95V) and the maximum power density (439 mW/cm2) have been achieved using hydrogen as the fuel. Lower value of activation energy (0.36ev) of Pb0.3Fe0.2Co0.5O4-δ confirms that it is the efficient material to convert electrochemically hydrogen fuel into valuable electricity.