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The electrochemical properties of reduced graphene oxide film with capsular pores prepared by using oxalic acid as template
Author(s) -
Gao Xiangli,
Ma Wenhui,
Han Gaoyi,
Chang Yunzhen,
Zhang Ying,
Li Honggang
Publication year - 2019
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.4813
Subject(s) - oxalic acid , capacitance , materials science , graphene , gravimetric analysis , oxide , horizontal scan rate , chemical engineering , supercapacitor , power density , electrode , specific energy , electrolyte , electrochemistry , nanotechnology , analytical chemistry (journal) , chemistry , cyclic voltammetry , inorganic chemistry , chromatography , organic chemistry , power (physics) , physics , quantum mechanics , engineering , metallurgy
Summary By using oxalic acid (OA) as template and reducer, a novel approach is developed to prepare reduced graphene oxide films with capsular pores (C‐rGOFs) under a hydrothermal condition. The effect of preparation conditions including concentrations of OA and reaction temperatures on the films' structure and capacitive performances has been systematically investigated. The optimal C‐rGOF shows uniform capsule‐like morphology and exhibits a density of 1.18 g cm −3 . Tested by using a two‐electrode system, the optimal film shows gravimetric specific capacitance of about 234.9 F g −1 and volumetric specific capacitance of 277.2 F cm −3 . Additionally, the optimal film which shows good rate capability can retain 63.9% of initial capacitance at high scan rate of 1.0 V s −1 , which is much higher than that of the controlling reduced graphene oxide film (rGOF, 180.5 F g −1 , 373.6 F cm −3 and retain only 45.0% of its initial capacitance at 1.0 V s −1 ). The cells assembled by the optimal C‐rGOF exhibit maximum energy density of 7.5 Wh kg −1 , power density of 16.9 kW kg −1 , and excellent cycling stability with 91.2% capacitance retention after 21 000 cycles. It is believed that this method can be developed as a useful strategy to prepare rGO‐based materials for energy storage applications.