Novel application of aluminum salt for cost-effective fabrication of a highly creep-resistant nickel-aluminum anode for a molten carbonate fuel cell

摘要

A one-step sintering process using aluminum acetate as an aluminum source is used to fabricate a nickel-based anode for a molten carbonate fuel cell (MCFC). The process is designed to replace existing partial or Ml oxidation and reduction processes, which are quite complicated and expensive. The aim is to simplify the fabrication process of a highly creep-resistant Ni-Al anode and eventually to contribute to the commercialization of a MCFC. Considering the solubility limit of Al in Ni. two types of anodes, Ni-2.5 wt. percent Al and Ni-5 wt. percentAl, are fabricated by sintering at either 1000 or 1100 deg C for 2 h in a 99.5 percent H_2 atmosphere. After characterizing the resulting material by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy. it is confirmed that among the anodes fabricated, the Ni-5 wt. percentAl sample sintered at 1100 deg C contained the most suitable Al_2O_3 in a dispersed form. A 100-h creep test reveals that the creep strain of the anode has the lowest value of 1.3 percent compared with the other anodes. This value is superior to the creep strain of 2.3 percent obtained from a Ni-5 wt. percentAl anode using Al powder as a fine Al_2O_3 dispersion source in a Ni-base anode matrix. A single cell using the Ni-5 wt. percent Al anode fabricated in this study shows a stable closed-circuit voltage of 0.795 V for 1000 h at 150mA cm~(-2).