Promising electrochemical study of titanate based anodes in direct carbon fuel cell using walnut and almond shells biochar fuel

The direct carbon fuel cell (DCFC) is an efficient device that converts the carbon fuel directly into electricity with 100% theoretical efficiency contrary to practical efficiency around 60%. In this paper four perovskite anode materials La0.4Sr0.6M0.09Ti0.91O3-δ (M = Ni, Fe, Co, Zn) have been prepared using sol-gel technique to measure the performance of the device using solid fuel. These materials have shown reasonable stability and conductivity at 700 °C. Further structural analysis of as-prepared anode material using XRD technique reveals a single cubic perovskite structure with average crystallite size roughly 47 nm. Walnut and almond shells biochar have also been examined as a fuel in DCFC at the temperature range 400–700 °C. In addition, Elemental analysis of walnut and almond shells has shown high carbon content and low nitrogen and sulfur contents in the obtained biochar. Subsequently, the superior stability of as-prepared anode materials is evident by thermogravimetric analysis in pure N2 gas atmosphere. Conversely, the LSFT anode has shown the highest electronic conductivity of 7.53Scm−1 at 700 °C. The obtained power density for LSFTO3-δ composite anode mixed in sub-bituminous coal, walnut and almond shells biochar is of 68, 55, 48 mWcm−2 respectively. A significant improvement in performance of DCFC (78 mWcm−2) was achieved.