Improvement of conversion efficiency of solid oxide fuel cell to apply to electric vehicle

采用Ni/Gd掺杂CeO_2金属陶瓷（GDC）阳极的固体氧化物燃料电池（SOFC）在900 °C下以100%的干甲烷（CH_4）为燃料实现了稳定的发电，最大功率密度为170 mW/cm^2。SOFC即使在运行120 h后也没有降解。用电流中断法测量了Ni/GDC阳极在氢燃料和4.5%干甲烷燃料中的直流极化，并与Ni/YSZ、Pt/YSZ和Pt阳极进行了比较。在氢燃料和4.5%干甲烷燃料中，Ni/GDC阳极的氧活性的表观反应级数均小于Ni/YSZ、Pt/YSZ和Pt阳极。基于先前提出的Ni/YSZ和Pt/YSZ阳极在氢燃料和4.5%干甲烷燃料中的阳极反应机理，具有Ni/GDC阳极的SOFC在100%干甲烷燃料中的稳定发电可能是由于YSZ中的氧与阳极上的三相边界上的氧之间的高平衡常数。

Stable power generation from a solid oxide fuel cell (SOFC) with a Ni/Gd-doped CeO_2 Cermet (GDC) anode in 100% dry-methane (CH_4) fuel was achieved at a maximum power density of 17OmW/cm^2 at 900 °C. The SOFC did not degrade even after 120 h of operation. The DC polarization of the Ni/GDC anode in hydrogen (H_2) fuel and in 4.5% dry-methane fuel was measured (by using the current interruption method) and then compared with those of Ni/YSZ, Pt/YSZ and Pt anodes. The apparent reaction orders of the oxygen activity for Ni/GDC anodes in both hydrogen fuel and 4.5% dry-methane fuel were smaller than those for Ni/YSZ, Pt/YSZ, and Pt anodes. Based on the previously proposed anode reaction mechanism for Ni/YSZ and Pt/YSZ anodes in hydrogen fuel and 4.5% dry-methane fuel, the stable power generation of the SOFC with the Ni/GDC anode in 100% dry-methane fuel was probably due to the high equilibrium constant between the oxygen in YSZ and the oxygen on the three-phase boundary on the anodes.