Lithium zirconate coated LiNi_(0.8)Co_(0.15)Al_(0.05)O_2 as a high-performance electrode material for advanced fuel cells

摘要

Surface modifcation of electrode materials could effectively enhance catalytic activity and stability for low temperature solid oxide fuel cells. In this paper, LiNi_(0.8)Co_(0.15)Al_(0.05)O_2 (NCAL), material with 1 wt Li_2ZrO_3 (LZO) surface coating were successfully synthesized by a simple wet chemical method. The crystal structure, surface morphology and electrochemical properties of the modifed NCAL materials were investigated by X-ray diffraction, scanning electron microscopy and photoelectron spectroscopy. The obtained results showed that the NCAL coated with LZO exhibited superior electrochemical performance. According to the EIS results, the polarization resistance of the 1 wt LZO-modifed NCAL based fuel cell at 550 ℃ was only 0.303 Ω cm~2, respectively, which were much lower than pure NCAL (1.33 Ω cm~2). The results show that the LZO surfaced coated NCAL could be a promising anode material towards high-performance advanced fuel cells.Combined with XRD and XPS analysis, it can be inferred that: the surface modifcation of LZO did not affect the structure of the raw material, and during the test, LZO enabled the effective distribution of the oxygen vacancies on the surface of the material, which accelerated the catalytic activity of the electrode during the discharge process.