Unusually Huge Charge Storage Capacity of Mn3O4-Graphene Nanocomposite Achieved by Incorporation of Inorganic Nanosheets.
Remarkable improvement in electrode performance of Mn3O4-graphene nanocomposites for lithium ion batteries can be obtained by incorporation of a small amount of exfoliated layered MnO2 or RuO2 nanosheets. The metal oxide nanosheet-incorporated Mn3O4-reduced graphene oxide (rGO) nanocomposites are synthesized via growth of Mn3O4 nanocrystals in the mesoporous networks of rGO and MnO2/RuO2 2D nanosheets. Incorporation of metal oxide nanosheets is highly effective in optimizing porous composite structure and charge transport properties, resulting in a remarkable increase of discharge capacity of Mn3O4-rGO nanocomposite with significant improvement of cyclability and rate performance. The observed enormous discharge capacity of synthesized Mn3O4-rGO-MnO2 nanocomposite (∼1600 mA·h·g(-1) for the 100th cycle) is the highest value among reported data for Mn3O4-rGO nanocomposite. Despite much lower electrical conductivity of MnO2 than RuO2, the MnO2-incorporated nanocomposite at optimal composition (2.5 wt %) shows even larger discharge capacities with comparable rate characteristics compared with the RuO2-incorporated homologue. This finding underscores that the electrode performance of the resulting nanosheet-incorporated nanocomposite is strongly dependent on its pore and composite structures rather than on the intrinsic electrical conductivity of the additive nanosheet. The present study clearly demonstrates that, regardless of electrical conductivity, incorporation of metal oxide 2D nanosheet is an effective way to efficiently optimize the electrode functionality of graphene-based nanocomposites.
Department of Chemistry and Nanoscience, College of Natural Sciences, Ewha Womans University , Seoul 03760, Korea.
Kanyaporn
K
Adpakpang
Department of Chemistry and Nanoscience, College of Natural Sciences, Ewha Womans University , Seoul 03760, Korea.
Xiaoyan
X
Jin
Department of Chemistry and Nanoscience, College of Natural Sciences, Ewha Womans University , Seoul 03760, Korea.
Seul
S
Lee
Department of Chemistry and Nanoscience, College of Natural Sciences, Ewha Womans University , Seoul 03760, Korea.
Seung Mi
SM
Oh
National Institute for Nanomaterials Technology, Pohang University of Science and Technology , Pohang 37673, Korea.
Nam-Suk
NS
Lee
Department of Chemistry and Nanoscience, College of Natural Sciences, Ewha Womans University , Seoul 03760, Korea.
Seong-Ju
SJ
Hwang
energy storage; graphene; layered compounds; nanocomposites; nanosheets