超级电容器
循环伏安法
介电谱
电解质
X射线光电子能谱
电化学
材料科学
比表面积
化学工程
电极
电容
氧化还原
拉曼光谱
分析化学(期刊)
化学
有机化学
冶金
催化作用
物理化学
工程类
物理
光学
作者
Ekaterina A. Arkhipova,Roman Yu. Novotortsev,Anton S. Ivanov,Konstantin I. Maslakov,Serguei V. Savilov
标识
DOI:10.1016/j.est.2022.105699
摘要
Processing of renewable, abundant, and low-cost biomass into porous carbon materials for application in supercapacitor electrodes has been attracting interest in last years. In this study, activated carbons (ACs) were produced via carbonization of rice husk followed by the chemical activation with KOH. SEM, Raman spectroscopy, XPS, and low temperature nitrogen physisorption were used to characterize the morphology, defectiveness, surface composition and textural parameters of the synthesized ACs. Activation significantly increased the specific surface area of AC up to 2700 m 2 ·g −1 forming a well-developed porous structure favorable for charge accumulation. The electrochemical performance of ACs was tested in the 1 M Na 2 SO 4 and 1 M Na 2 SO 4 + 0.03 M K 3 Fe[CN] 6 electrolytes by cyclic voltammetry, galvanostatic charge – discharge measurements and impedance spectroscopy. The addition of redox-active K 3 Fe[CN] 6 to the conventional 1 M Na 2 SO 4 electrolyte noticeably (in 3.6 times) increased the specific capacitance of the AC-based electrode up to 400 F·g −1 at a current density of 0.5 A·g −1 . The high capacitance retentions of 99.6 % in 1 M Na 2 SO 4 and 97.7 % in 1 M Na 2 SO 4 + 0.03 M K 3 Fe[CN] 6 after 5000 charge–discharge cycles, developed microporosity and high electrochemical performance make the rice husk-derived AC a promising electrode material for energy storage applications. At a current density of 0.5 A·g −1 the symmetric AC2-based supercapacitor with the redox-active electrolyte delivered an energy density of 16.7 Wh·kg −1 at power density of 0.4 kW·kg −1 . • Activated carbonized rice husk as supercapacitor electrode • High specific surface area (2700 m 2 ·g −1 ) and total pore volume (1.540 cm 3 ·g −1 ) • High specific capacitance of 400 F g −1 at 0.5 A g −1 in redox-active electrolyte • High capacitance retention (>97.7 %) after 5000 charge–discharge cycles
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