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A SnO2/graphene composite as a high stability electrode for lithium ion batteries Carbon Volume 49, Issue 1, January 2011：133–139 * Introduction Lithium ion batteries using the lithium transition metal oxide cathode and graphite anode have been the power sources for various mobile communication devices, portable electronic devices, and electric/hybrid vehicles. However, graphite has an inherent limitation with a theoretical gravimetric capacity estimated at 370 mAh/g. For the purpose of improving the energy density of batteries, scientists have made great efforts to explore alternative anode materials with higher capacity. * As a large band gap semiconductor, SnO2 has attracted a lot of attention due to its relatively high theoretical reversible capacity (790 mAh/g), which is more than twice that of the currently used graphite. There are two electrochemical processes in the SnO2-based lithium ion batteries: As the reaction (2) demonstrates, a volume change of 200–300% occurs during lithiation/delithiation process between Sn and Li4.4Sn. This reaction can generate a large internal stress, leading to cracking of electrode, loss of electrical contact, large initial irreversible capacity, and eventually quick fading of capacity. * To overcome the internal stress problem, great attention has been paid to nano-structured SnO2 and SnO2/carbon composite electrodes. Graphene, a monolayer of graphite, exhibits a number of intriguing unique properties such as high surface area of over 2600m2/g, large surface-to-volume ratio, high room temperature (RT) carrier mobility, conductance quantization Therefore, graphene has been regarded as an ideal carbon nanostructure which can be used to design high performance SnO2/carbon composite electrodes. * Up to date, there have been a few reports about the preparation of SnO2/graphene composite. Paek et al. [2] synthesized a SnO2/graphene composite with three-dimensionally delaminated flexible structure by mechanical mixing SnO2 nanoparti