【摘要】 为了提高原始石墨毡(GF)对V3+/V2+氧化还原反应的电催化活性和降低析氢反应对电池性能的影响,本文采用水热法将氧化镉(CdO)纳米颗粒负载于石墨毡表面,制备出改性石墨毡(CdO/GF)作为高性能的钒电池负极。通过扫描电镜(SEM)、X射线衍射分析(XRD)进行表面形貌和物相分析得出:CdO纳米颗粒均匀负载于石墨毡纤维表面;线性扫描伏安法(LSV)、循环伏安测试(CV)、交流阻抗谱测试(EIS)表明:相对于GF,CdO/GF有效抑制了析氢反应的活性,CdO/GF对于V3+/V2+氧化还原反应的电化学活性和可逆性有显著的提高,电荷转移阻抗也有明显的减小;单电池测试中,对比GF,CdO/GF的放电容量衰减速率有显著的下降,在90 mA·cm-2的电流密度下的电压效率和能量效率提高了约5%。在多次充放电循环过程中,CdO/GF的催化性能显示出良好的稳定性。更多还原

【Abstract】 To improve the electrocatalytic activity of pristine graphite felt(GF) towards the V3+/V2+redox couple and reduce the impact of the hydrogen evolution reaction(HER) on battery performance, in this study, cadmium oxide(CdO) nanoparticles were loaded onto the surface of graphite felt fibers by the hydrothermal method to prepare a high-performance negative electrode of a VRFB. The results of scanning electron microscopy(SEM), X-ray diffraction(XRD) showed that CdO nanoparticles were uniformly loaded on the surface of graphite felt fibers; Linear sweep voltammetry(LSV), cyclic voltammetry(CV) and electrochemical impedance spectroscopy(EIS) results indicated that the activity of HER was significantly inhibited by the presence of CdO. Furthermore, the electrochemical activity and reversibility of cadmium-doped graphite felt(CdO/GF) for the V3 +/V2 +redox reaction were significantly improved, and the charge transfer resistance was also significantly reduced as compared with GF.In a single-cell test, compared to GF, the discharge capacity attenuation rate of CdO/GF significantly decreased, the voltage efficiency and energy efficiency of CdO/GF were enhanced by approximately 5% at a current density of 90 mA·cm-2. Moreover, the catalytic performance of CdO/GF showed good stability during constant current 100 charge-discharge tests.更多还原