Carbonate-tin composite liquid anode for solid oxide direct carbon fuel cell

The SnO2 blocking film deposited on the anode-electrolyte interface during operation degrades the performance of a liquid tin (Sn) anode direct carbon fuel cell (DCFC). In the present study, Li-K carbonate is introduced to solve the SnO2 problem. A composite anode composed of molten carbonate and Sn was fabricated. The reaction kinetics of the composite anodes were characterized by performing electrochemical tests on different anodes at various metal-carbonate ratios. The shapes of the polarization curves of the different anodes changed dramatically, indicating a significant difference in the reaction mechanism and the mass transport process inside the composite anode. Electrochemical performance of composite anode was restored during polarization tests. A composite anode with 2 mol% molten carbonate demonstrates the highest power density as well as stable performance. Carbon black was fed to the 2 mol.% molten carbonate anode as a test of carbon conversion ability. By mixing carbon black with the liquid composite anode, both the fuel cell's performance and its stability were improved.