Tunable Sub-nanopores of Graphene Flake Interlayers with Conductive Molecular Linkers for Supercapacitors.
Although there are numerous reports of high performance supercapacitors with porous graphene, there are few reports to control the interlayer gap between graphene sheets with conductive molecular linkers (or molecular pillars) through a π-conjugated chemical carbon-carbon bond that can maintain high conductivity, which can explain the enhanced capacitive effect of supercapacitor mechanism about accessibility of electrolyte ions. For this, we designed molecularly gap-controlled reduced graphene oxides (rGOs) via diazotization of three different phenyl, biphenyl, and para-terphenyl bis-diazonium salts (BD1-3). The graphene interlayer sub-nanopores of rGO-BD1-3 are 0.49, 0.7, and 0.96 nm, respectively. Surprisingly, the rGO-BD2 0.7 nm gap shows the highest capacitance in 1 M TEABF4 having 0.68 nm size of cation and 6 M KOH having 0.6 nm size of hydrated cation. The maximum energy density and power density of the rGO-BD2 were 129.67 W h kg(-1) and 30.3 kW kg(-1), respectively, demonstrating clearly that the optimized sub-nanopore of the rGO-BDs corresponding to the electrolyte ion size resulted in the best capacitive performance.
Department of Chemistry, ‡Department of Energy Science, and §Centre for Integrated Nanostructure Physics (CINAP), Institute of Basic Science (IBS), Sungkyunkwan University , 2066 Seoburo, Jangan-gu, Suwon, Gyeonggi-do 440-746, Republic of Korea.
Keunsik
K
Lee
Department of Chemistry, ‡Department of Energy Science, and §Centre for Integrated Nanostructure Physics (CINAP), Institute of Basic Science (IBS), Sungkyunkwan University , 2066 Seoburo, Jangan-gu, Suwon, Gyeonggi-do 440-746, Republic of Korea.
Yeoheung
Y
Yoon
Department of Chemistry, ‡Department of Energy Science, and §Centre for Integrated Nanostructure Physics (CINAP), Institute of Basic Science (IBS), Sungkyunkwan University , 2066 Seoburo, Jangan-gu, Suwon, Gyeonggi-do 440-746, Republic of Korea.
Yunhee
Y
Cho
Department of Chemistry, ‡Department of Energy Science, and §Centre for Integrated Nanostructure Physics (CINAP), Institute of Basic Science (IBS), Sungkyunkwan University , 2066 Seoburo, Jangan-gu, Suwon, Gyeonggi-do 440-746, Republic of Korea.
Sae Mi
SM
Lee
Department of Chemistry, ‡Department of Energy Science, and §Centre for Integrated Nanostructure Physics (CINAP), Institute of Basic Science (IBS), Sungkyunkwan University , 2066 Seoburo, Jangan-gu, Suwon, Gyeonggi-do 440-746, Republic of Korea.
Yonghun
Y
Shin
Department of Chemistry, ‡Department of Energy Science, and §Centre for Integrated Nanostructure Physics (CINAP), Institute of Basic Science (IBS), Sungkyunkwan University , 2066 Seoburo, Jangan-gu, Suwon, Gyeonggi-do 440-746, Republic of Korea.
Hanleem
H
Lee
Department of Chemistry, ‡Department of Energy Science, and §Centre for Integrated Nanostructure Physics (CINAP), Institute of Basic Science (IBS), Sungkyunkwan University , 2066 Seoburo, Jangan-gu, Suwon, Gyeonggi-do 440-746, Republic of Korea.
Hyoyoung
H
Lee
bis-diazonium salt; diazotization; graphene; sub-nanopore; supercapacitor