Study On The Fuel And Anode Materials Of Direct Carbon Fuel Cell

Direct carbon fuel cell(DCFC),as an efficient and clean power generation technology,is of significance in improving energy efficiency of fuels,reducing greenhouse gas emissions and alleviating the energy crisis.The main problems of DCFC are their low output power density and low utilization rate of carbon fuel.The key to solve those problems is to improve the electrochemical oxidation activity of carbon at the anode.In this work,carbonized biomass is used as fuel of DCFC,and the effects of impurities in the biomass on the structure of carbon and the anode kinetics are investigated.Besides,Ni O-Ce_0.8Sm_0.2O_1.9(SDC)anode material is modified in this work,and the the influences of anode material on the reactivity and carbon utilization efficiency are studied.The biomass charcoal obtained via thermal cracking of reed rods is used as the fuel of DCFC,and the influence of the main soluble impurity KCl on the carbonization of reed rods is investigated.In the carbonization process,KCl reduces the degree of graphitization of biomass carbon,thereby improving the electrochemical oxidation activity of carbon and the performance of single cells.In addition,the straight tubular structure of reed rod biochar is beneficial to the mass transfer and electron conduction in the anode.A single cell with that fuel exhibits maximum output power densities of378,307,183 and 80 m W cm^-2 at 750,700,650 and 600 ^oC,respectively.Carbon monoxide is the major by-product of the anode reaction in DCFC.In order to improve the electrochemical oxidation activity of CO and the fuel utilization efficiency,Zr O₂ is added in the conventional Ni O-SDC anode material via impregnation,which reduces the activity of the anode and the maximum output power density of the single cell.However,a cerium-zirconium solid solution is formed in the anode at the same time,which has a good catalytic activity for the oxidation of CO,thereby improving the energy efficiency of the carbon fuel.Meanwhile,the formation of cerium-zirconium solid solution improves the carbon deposition resistance of the anode and the stability of the single cell.