Hierarchical networks of redox-active reduced crumpled graphene oxide and functionalized few-walled carbon nanotubes for rapid electrochemical energy storage.
Crumpled graphene is known to have a strong aggregation-resistive property due to its unique 3D morphology, providing a promising solution to prevent the restacking issue of graphene based electrode materials. Here, we demonstrate the utilization of redox-active oxygen functional groups on the partially reduced crumpled graphene oxide (r-CGO) for electrochemical energy storage applications. To effectively utilize the surface redox reactions of the functional groups, hierarchical networks of electrodes including r-CGO and functionalized few-walled carbon nanotubes (f-FWNTs) are assembled via a vacuum-filtration process, resulting in a 3D porous structure. These composite electrodes are employed as positive electrodes in Li-cells, delivering high gravimetric capacities of up to ∼170 mA h g(-1) with significantly enhanced rate-capability compared to the electrodes consisting of conventional 2D reduced graphene oxide and f-FWNTs. These results highlight the importance of microstructure design coupled with oxygen chemistry control, to maximize the surface redox reactions on functionalized graphene based electrodes.
George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA. seung.lee@me.gatech.edu.
Byeongyong
B
Lee
Rare Metals Research Center, Korea Institute of Geoscience and Mineral Resources, Yuseong-gu, Deajeon 305-350, Korea. hdjang@kigam.re.kr and Department of Nanomaterials Science and Engineering, University of Science & Technology, Deajeon 305-350, Korea. hdjang@kigam.re.kr.
Chongmin
C
Lee
George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA. seung.lee@me.gatech.edu.
Tianyuan
T
Liu
School of Chemical & Biomolecular Engineering, Center for Innovative Fuel Cell and Battery Technologies, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Kwangsup
K
Eom
Department of Applied Chemistry, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.
Zhongming
Z
Chen
Department of Applied Chemistry, Waseda University, 3-4-1 Okubo, Shinjuku-ku, Tokyo 169-8555, Japan.
Suguru
S
Noda
School of Chemical & Biomolecular Engineering, Center for Innovative Fuel Cell and Battery Technologies, Georgia Institute of Technology, Atlanta, GA 30332, USA.
Thomas F
TF
Fuller
Rare Metals Research Center, Korea Institute of Geoscience and Mineral Resources, Yuseong-gu, Deajeon 305-350, Korea. hdjang@kigam.re.kr and Department of Nanomaterials Science and Engineering, University of Science & Technology, Deajeon 305-350, Korea. hdjang@kigam.re.kr.
Hee Dong
HD
Jang
George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA. seung.lee@me.gatech.edu.
Seung Woo
SW
Lee