Simple Designed Synthesis of Graphene Based Nanocomposites for Energy Related Applications Yuanzhe Piao Graduate school of Convergence Science and Technology, Seoul National University Pure and Applied Chemistry International Conferences (PACCON) 2013 The Tide Resort, Thailand. January 23, 2013 – January 25, 2013

2 Lithium-ion battery Kang Xu et al., Chem. Rev., 104 (2004) 4303 Cathode Layered structure Spinel structure Olivine structure Anode Carbonaceous material Transition metal oxide Alloys

3 Graphene – single layer graphite π -orbital σ -bond Hexagonal network of Carbon – sp 2 bonding sp 2 sp 3 High surface area (2,630 m 2 g -1 ) vs. graphite (10 m 2 g -1 ) & CNT (1,315 m 2 g -1 ) High electrical conductivity Unique mechanical strength Chemical stability … Properties 1. Graphene based nanocomposites 1. Graphene based nanocomposites

4 Graphene nanocomposite materials for energy devices: electrode materials for lithium ion batteries and supercapacitors. Graphene

5 Electrochimica Acta, 2012, 59, Graphene–carbon nanotube composite Synthesis of a graphene–carbon nanotube composite and its electrochemical sensing of hydrogen peroxide

6 Graphene–carbon nanoparticle composite Journal of Power Source, 2012 Enhanced electrocatalysis of PtRu onto graphene separated by Vulcan carbon spacer

HRTEM images of GO–S composites (insets: power spectra of the region indicated by a circle). 7 Monodisperse nanoparticles onto graphene for lithium ion batteries A facile hydrazine-assisted hydrothermal method for the deposition of monodisperse SnO 2 nanoparticles onto graphene for lithium ion batteries

(a) The charge–discharge curves of GO–S at a current density of 100 mA g -1, (b) cyclic voltammograms of the GO–S at a scanning rate of 0.1 mV s -1, (c) cycling performance of GO–S, SnO 2 and graphene at a current density of 100 mA g1, (d) cycling performance of GO–S at various current densities after 1 cycle at a current density of 100 mA g J. Mater. Chem., 2012, 22,

A one-pot microwave-assisted non-aqueous sol–gel approach RSC Advances, 2011, 1, 1687–1690 9

10 Cycling performance of GNS (triangles, red), pure Fe 3 O 4 (diamonds, magenta), IGC2 (squares, blue), IGC3 (circles, green) and at various current densities. Empty symbols indicate discharge and full symbols charge.

11 2. Carbon coated nanoparticles 2. Carbon coated nanoparticles Facile scalable synthesis of magnetite nanocrystals embedded in carbon matrix as superior anode materials for lithium-ion batteries

The discharge/charge profiles of (a) the as-prepared magnetite-C nanocomposites, and (b) the sample prepared without pre-heat treatment under vacuum. (c) Cycle performance of each sample. Open symbols: discharge, closed symbols: charge. (d) Effect of current rate on the relative discharge capacities (the data were obtained by normalizing the third discharge capacities at various C rates to that at 0.1 C). 12 Yuanzhe Piao*, et al. Chem. Commun., 2010, 46,

13 Direct Synthesis of Self-Assembled Ferrite/Carbon Hybrid Nanosheets for High Performance Lithium-Ion Battery Anodes

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15 Yuanzhe Piao*, et al. J. Am. Chem. Soc., 2012, 134,

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