复合材料Fe_(0.5)Co_(0.25)Ni_(0.25)O_x-Ti_4O_7电极的制备及催化活性研究

采用光降解沉积法合成复合材料Fe0.5Co0.25Ni0.25Ox-Ti4O7电极,利用SEM-EDS、TEM观察电极材料的形貌、元素分布以及粉体的显微结构。电极材料呈多孔结构,铁、钴、镍氧化物按设计的摩尔比包覆在Ti_4O_7上,以高缺陷态存在;通过在0.1mol/L KOH中的循环伏安测试(CV)和线性伏安扫描测试(LSV)测试,材料具有氧还原(ORR)和氧析出(OER)催化活性;以Fe_(0.5)Co_(0.25)Ni_(0.25)O_x-Ti_4O_7为催化材料组装成有机体系的锂氧气电池,在100mA/g条件下恒流充放电,电池首次放电比容量可达6 000mAh/g,随后过程衰减较快;而在100mA/g和800mAh/g条件下恒流恒容充放电时,放电电压可保持在2.7V以上稳定循环25圈。

Preparation and Catalytic Activity of Composite Fe0.5Co0.25Ni0.25Ox-Ti4O7 Electrode

The composite material Fe0.5Co0.25Ni0.25Ox-Ti4O7 electrode was synthesized by photochemical metal-organic deposition (PMOD). Scanning electron microscope (SEM) combined with energy dispersive spectrometer (EDS) and transmission electron microscope (TEM) were used to confirm the morphology and element distribution of electrode materials and the microstructure of the sample powder. The electrode materials Fe0.5Co0.25Ni0.25Ox-Ti4O7 were porous, in which the FeOx, CoOx, and NiOx coated on Ti4O7 by the designed molar ratio and existed in the state of high defect density. The cyclic voltammetry (CV) and linear voltammetry (LSV) tests in 0.1 mol/L KOH electrolyte were performed. The materials have oxygen reduction (ORR) and oxygen precipitation (OER) catalytic activities. Aprotic lithium oxygen batteries were assembled with Fe0.5Co0.25Ni0.25Ox-Ti4O7 materials. The constant current charge and discharge at 100 mA/g, an initial discharge specific capacity of the batteries can reach more than 6 000 mAh/g and the subsequent process decays faster. The batteries can maintain discharge voltage stable above 2.7 V 25 circles under the conditions of the constant current of 100 mA/g and the constant capacity of 800 mAh/g.