热处理对TiO2/AC电极材料结构及电化学性能的影响

Effect of heat treatment on structure and electrochemical performance of TiO2/AC electrode material

摘要:

为了研究不同热处理温度对TiO₂/AC电极材料结构及电化学性能的影响,采用溶胶-凝胶法制备该电极材料,通过扫描电子显微镜(SEM)、热重分析仪(TG-DTG)、比表面积及孔径分析仪(BET)、X射线衍射光谱仪(XRD)和电化学工作站对其微观结构和电化学性能进行表征分析. 结果表明：热处理使TiO₂呈絮状或颗粒状附着于活性炭表面及孔道中；随着热处理温度升高,TiO₂/AC比表面积先增大后减小,晶型由锐钛型逐渐向金红石型转变,晶粒尺寸也逐步增大,比电容值先增大后减小；当热处理温度为450 ℃时,TiO₂/AC电极材料的晶型呈锐钛型且晶粒尺寸适中、有效比表面积最大、电化学性能最优.

Abstract:

To explore the effect of different heat treatment temperature on structure and electrochemical performance of electrode material(TiO₂/AC) prepared by sol-gel method, Scanning Electron Microscopy (SEM), thermal gravimetric analysis (TG-DTG), Brunauer-Emmett-Teller gas adsorption method (BET), X-ray diffraction (XRD) and electrochemical workstation are introduced to analyses the micro-structure and electrochemical performance. The results show that the crystal anatase TiO₂ nanoparticles were attached to the surface and pores in the activated carbon by heat treatment. With the increase of temperature, the specific surface area increased first and then decreased. Moreover, the crystal form changed from anatase to rutile and grain size increasing gradually, and the specific capacitance of corresponding electrode increased first and then decreased. When the temperature was 450 ℃, crystal form was anatase ; the grain size, effective specific surface area and electrochemical performance were the best.