Nickel volatilization phenomenon on the Ni-CGO anode in a cathode supported SOFC operated at low concentrations of H2
Nickel volatilization phenomenon on the Ni-CGO anode in a cathode supported SOFC operated at low concentrations of H2
复制标题
在低浓度氢气下运行的阴极支持的 SOFC 中 Ni-CGO 阳极上的镍挥发现象
DOI：
10.1016/j.ijhydene.2011.09.007
复制
发表时间：
2012
影响因子：
7.2
通讯作者：
Abuliti Abudula
中科院分区：
文献类型：
--
作者：
Gang Chen;Guoqing Guan;Yutaka Kasai;Abuliti Abudula
阴极支撑固体氧化物燃料电池镍基阳极在低氢浓度、高电流密度下工作时，通常会出现快速劣化现象。为了阐明这一现象，采用硝酸-柠檬酸盐溶胶-凝胶法制备了Ni：Ce质量比为0. 8 Gd 0. 2 O 1.9（CGO）的均匀NiO-Ce 0. 8 Gd 0. 2 O 1.9（CGO）复合粉体，并采用浆料涂覆法将其涂覆在LSM-CGO阴极支撑SOFC上。所制备的燃料电池表现出良好的性能时，他们在纯H2操作。但在高电流密度下，以低浓度H2为燃料时，Ni-CGO阳极通常会出现快速降解现象。在5.66%H2和高电流密度下反复降解后的Ni-CGO阳极的SEM照片中观察到了明显的微观结构损伤和Ni的烧结。此外，通过EDX分析还发现，当重复该降解过程若干次时，Ni-CGO阳极中的Ni量减少。推测当H2O/H2分压比较高时，氢氧化镍的挥发应发生在Ni-CGO阳极的三相界面处。
Rapid degradation phenomenon is generally occurred when Ni-based anode on a cathode-supported SOFC is operated in low concentrations of hydrogen at high current density. In order to clarify this phenomenon, homogenous NiO-Ce0.8Gd0.2O1.9(CGO) composites powder with fixed weight ratio of Ni:Ce was synthesized using a nitric-citrate sol-gel method, and coated on LSM-CGO cathode-supported SOFC using slurry coating method. As-prepared fuel cells exhibited good performance when they were operated at pure H2. However, rapid degradation phenomenon on Ni-CGO anode usually happened when low concentration of H2was used as fuel at high current density. Obvious microstructure damage and sintering of Ni were observed in SEM micrographs of Ni-CGO anode after repeated degradation process in 5.66% of H2at high current density. Furthermore, the decrease in Ni amount in Ni-CGO anode was also found via EDX analysis when this degradation process was repeated for several times. It is inferred that the volatilization of nickel hydroxide should happen at triple-phase boundaries of Ni-CGO anode when high partial pressure ratio of H2O and H2appeared in this case.