PDF(Pubmed)
Abstract：
Asymmetric supercapacitors (ASCs) with two dissimilar electrodes are known to exhibit relatively moderate energy and power densities. If electrodes derived from earth-abundant materials or renewable resources such as lignocellulosic biomass (LCB) are used for fabrication, energy storage systems are expected to become less expensive and more sustainable. Hybrid electrode materials have advantages such as higher surface area, better chemical stability, and superior energy density. This study reports on the synthesis of a novel hybrid electrode material containing porous carbon (POC) and copper ferrite, which is designated as POC@Cu-ferrite, and its electrochemical performance in ASC configuration. Corn stover derived hydrochar is utilized for the sol-gel synthesis of POC@Cu-ferrite hybrid material using earth-abundant Cu and Fe-based precursors. This material is characterized using X-ray diffraction (XRD), Raman spectroscopy, Brunauer-Emmett-Teller (BET) surface area analyzer, and scanning and transmission electron microscopy (SEM/TEM). As-synthesized Cu-ferrite is found to contain 89.2% CuFe2O4 and 10.8% Fe2O3, whereas other phases such as Fe3O4, CuFeO2, and CuO are observed for the POC@Cu-ferrite. BET-specific surface area (SSA) and pore volume of POC@Cu-ferrite are observed as 1068 m2/g and 0.72 cm3/g, respectively. POC@Cu-ferrite hybrid electrode is used with POC opposite electrode to fabricate ASC, which is tested using Gamry G-300 potentiostat/galvanostat/ZRA to obtain cyclic voltammetry (CV) profiles and galvanostatic charge-discharge (GCD) plots. ASC is also prepared using Cu-ferrite and POC materials and its specific capacitance and stability are compared with ASCs prepared with POC@Cu-ferrite and POC or graphene nanoplatelets (GNPs) electrodes. POC@Cu-ferrite hybrid electrode is found to be superior with a 2-fold higher capacitance and significant electrochemical stability over 100 GCD cycles as compared to the Cu-ferrite electrode.
摘要：
已知具有两个不同电极的不对称超级电容器(ASC)表现出相对适中的能量和功率密度。如果使用来自地球丰富的材料或可再生资源（例如木质纤维素生物质（LCB））的电极进行制造，预计储能系统将变得更便宜，更可持续。杂化电极材料具有较高的比表面积、更好的化学稳定性，和优越的能量密度。本研究报道了一种含有多孔碳（POC）和铜铁氧体的新型混合电极材料的合成，被指定为POC@Cu铁氧体，及其在ASC构型下的电化学性能。玉米秸秆衍生的水炭用于使用地球丰富的Cu和Fe基前体的POC@Cu-铁氧体混合材料的溶胶-凝胶合成。使用X射线衍射(XRD)对该材料进行表征,拉曼光谱,Brunauer-Emmett-Teller(BET)表面积分析仪,扫描和透射电子显微镜(SEM/TEM)。发现合成的Cu铁氧体含有89.2％的CuFe2O4和10.8％的Fe2O3，而POC@Cu铁氧体则观察到其他相如Fe3O4，CuFeO2和CuO。POC@Cu-铁氧体的BET比表面积(SSA)和孔体积分别为1068m2/g和0.72cm3/g,分别。POC@Cu-铁氧体混合电极与POC对电极一起制造ASC，其使用GamryG-300恒电位仪/恒电流仪/ZRA进行测试以获得循环伏安法(CV)曲线和恒电流充放电(GCD)图。还使用Cu-铁氧体和POC材料制备ASC,并且将其比电容和稳定性与用POC@Cu-铁氧体和POC或石墨烯纳米片(GNPs)电极制备的ASC进行比较。与Cu-铁氧体电极相比，POC@Cu-铁氧体混合电极在100个GCD循环中具有2倍的电容和显着的电化学稳定性。
