(Pr0.9La0.1)2(Ni0.74Cu0.21Ga0.05)O4＋δ纳米纤维阴极的制备及电化学性质

Preparation and Electrochemical Properties of (Pr_(0.9)La_(0.1))_2(Ni_(0.74)Cu_(0.21)Ga_(0.05))O_(4+δ) Nanofiber Cathode

采用静电纺丝法制备了(Pr_(0.9)La_(0.1))_2(Ni_(0.74)Cu_(0.21)Ga_(0.05))O_(4+δ)(PLNCG)氧化物纳米纤维。利用热重-差热分析(TG-DTA)、X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)和扫描电子显微镜(SEM)对材料的物相及微观形貌进行分析。研究表明950℃煅烧5 h得到平均直径420 nm、形貌均一的PLNCG氧化物纤维;1 000℃烧结2 h得到紧密附着在Ce_(0.9)Gd_(0.1)O_(2-δ)(CGO)电解质上的网状结构纤维阴极。电化学阻抗谱(EIS)测试结果表明纳米纤维阴极具有比粉体阴极更优越的性能。700℃的极化电阻(RP)为0.134Ω·cm^2,比同组分的粉末阴极减少32%(RP=0.197Ω·cm^2)。以纤维阴极构筑的电解质支撑单电池Ni-CGO/CGO/PLNCG在700℃的最大输出功率密度为231 m W·cm-2。氧分压测试结果表明阴极反应的速率控制步骤为电荷转移过程。

The oxide nanofiber （Pr0.9La0.1）2（Ni0.74Cu0.21Ga0.05）O4＋δ （PLNCG） is prepared by electrospinning technique. The phase and morphology evolution of the oxide nanofiber are characterized by Thermo-gravimetric-Differential thermal analysis （TG-DTA）, X-ray diffraction （XRD）, fourier transform infrared spectroscopy （FT-IR） and scanning electron microscopy （SEM）, respectively. The results show that PLNCG nanofiber with an average diameter of 420 nm is produced after sintering the precursors at 950℃ for 5 h. The nanofiber cathode is formed with mesh-like morphology and keep good contact with the Ce0.9Gd0.1O2-δ （CGO） electrolyte after heat-treated at 1 000℃ for 2 h. The electrochemical impedance spectrum （EIS） results indicate that the nanofiber cathode exhibits superior performance than the powder cathode. The polarization resistance （RP） of the nanofiber cathode is 0.134 Ω·cm2 at 700℃ in air, which is 32% less than the PLNCG powder cathode （RP=0.197 Ω·cm2）. The maximum power density of electrolyte-support single cell with PLNCG nanofiber cathode （Ni-CGO/CGO/PLNCG） reaches 231 mW·cm-2 at 700℃. The oxygen partial pressure measurement indicates that the charge transfer process is the reaction rate-limiting step of the nanofiber cathode.