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Boosting the Electrical Double‐Layer Capacitance of Graphene by Self‐Doped Defects through Ball‐Milling
Author(s) -
Dong Yue,
Zhang Su,
Du Xian,
Hong Song,
Zhao Shengna,
Chen Yaxin,
Chen Xiaohong,
Song Huaihe
Publication year - 2019
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.201901127
Subject(s) - materials science , capacitance , supercapacitor , gravimetric analysis , graphene , doping , specific surface area , capacitive sensing , nanotechnology , carbon fibers , composite material , chemical engineering , optoelectronics , composite number , electrode , electrical engineering , biochemistry , chemistry , organic chemistry , engineering , catalysis
Improving the capacitance of carbon materials for supercapacitors without sacrificing their rate performance, especially volumetric capacitance at high mass loadings, is a big challenge because of the limited assessable surface area and sluggish electrochemical kinetics of the pseudocapacitive reactions. Here, it is demonstrated that “self‐doping” defects in carbon materials can contribute to additional capacitance with an electrical double‐layer behavior, thus promoting a significant increase in the specific capacitance. As an exemplification, a novel defect‐enriched graphene block with a low specific surface area of 29.7 m 2 g −1 and high packing density of 0.917 g cm −3 performs high gravimetric, volumetric, and areal capacitances of 235 F g −1 , 215 F cm −3 , and 3.95 F cm −2 (mass loading of 22 mg cm −2 ) at 1 A g −1 , respectively, as well as outstanding rate performance. The resulting specific areal capacitance reaches an ultrahigh value of 7.91 F m −2 including a “self‐doping” defect contribution of 4.81 F m −2 , which is dramatically higher than the theoretical capacitance of graphene (0.21 F m −2 ) and most of the reported carbon‐based materials. Therefore, the defect engineering route broadens the avenue to further improve the capacitive performance of carbon materials, especially for compact energy storage under limited surface areas.