High quality NMP exfoliated graphene nanosheet-SnO2 composite anode material for lithium ion batteryElectronic supplementary information (ESI) available: TG/DTA studies, SEM/TEM images and dQ/dV plot. See DOI: 10.1039/c2cp43487c

• Main Authors: Ravikumar, Raman, Gopukumar, Sukumaran
• Format: Article
• Language: English
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c2cp43487c

A graphene nanosheet-SnO 2 (GNS-SnO 2 ) composite is prepared using N -methylpyrrolidone as a solvent to exfoliate graphene from graphite bar with the aid of CTAB by single phase co-precipitation method. The synthesized composites has been characterised physically by powder XRD which confirms the formation of the composite tetragonal SnO 2 crystal system with the low intense broad 002 plane for GNS. The sandwiched morphology of GNS-SnO 2 and the formation of nanosized particles (around 20 nm) have been confirmed by SEM and TEM images. The presence of sp 2 carbon in the GNS is clear by the highly intense G than D band in laser Raman spectroscopy analysis; furthermore, a single chemical shift has been observed at 132.14 ppm from solid-state 13 C NMR analysis. The synthesized composite has been electrochemically characterized using charge-discharge and EIS analysis. The capacity retentions at the end of the first 10 cycles is 57% (100 mA g −1 rate), the second 10 cycles is 77.83% (200 mA g −1 ), and the final 10 cycles (300 mA g −1 ) is 81.5%. Moreover the impedance analysis clearly explains the low resistance pathway for Li + insertion after 30 cycles when compared with the initial cycle. This superior characteristic of GNS-SnO 2 composite suggests that it is a promising candidate for lithium ion battery anode. A new concept of an NMP exfoliated graphite composite with SnO 2 via a homogeneous co-precipitation technique for cushioning volume expansion during insertion and extraction of Li + , improving the conductivity for the better Li + transport, highly ordered with high degree of sp 2 carbon.