| Summary: | 碩士 === 國立中興大學 === 材料科學與工程學系所 === 99 === In the study, the homemade platinum/carbon black (Pt/C) electrode material was used as the catalyst layer of the anode in vanadium redox flow battery (VRFB) to improve its performance . The Pt/C-10 wt%, 20 wt% and 30 wt% electrode materials were synthesized by thermal reflux method. Characteristics of the homemade Pt/C was investigated by X-ray diffraction , Field Emission Scanning Electron Microscope (FESEM), and Transmission Electron Microscope (TEM). The XRD results indicated that the Pt has FCC structure. The average particle size of Pt was 10±3 nm by FESEM and TEM. In addition, Pt partical was well dispersed on the carbon black
The anodic peak current of Pt/C 30 wt% was 104 mA, higher than that of carbon black, was 29 mA, at scan rate of 0.01 V/s by the Cyclic Voltammetry. Moreover, the cathode peak current of Pt/C 30 wt% was 55 mA higher than that of carbon black, was 19 mA. The dynamic scanning of Linear Sweep Voltammetry LSV in Rotating Disk Electrode (RDE) obtained the heterogeneous rate constant K0 cm/s and exchange current density i0 μA . The heterogeneous rate constant K0 cm/s was increased from 6.37 ×10-15 cm/s to 2.11×10-13 cm/s with increasing concentration of Pt loadings. The exchange current density i0 μA was increased from 3.79 μA to 82.96 μA with increasing concentration of Pt loading. The Pt/C catalyst had electrocatalysis active in VOSO4 electrode by electrochemical analysis.
The active layer in the anode electrode can improve the energy efficiency from 37.0% to 58.4% higher, than pristine graphite felt at constant current 10 mA. This study discovered that the Pt/C based on catalyst could effectively reduce the electrode resistance of the active layer from the charge-discharge curve. The VRB efficiency decreases in the order (high to low) of Pt/C 30 wt%＞Pt/C 20 wt%＞Pt/C 10 wt%＞raw graphite felt. The reaction rate and battery energy efficiency were improved by the Pt/C catalyst added in the electrodes.
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