Sandwiched CNT@SnO2@PPy nanocomposites enhancing sodium storage

CNT@SnO 2 @PPy nanocomposites were designed by combining liquid-phase deposition (LPD) and in-situ chemical-polymerization method for sodium-ion battery anodes. CNT@SnO 2 @PPy nanocomposites maintain one-dimensional structure of CNT in diameters of about 35–45 nm, moreover, the thickness of PPy coating is about 6–8 nm. Sandwiched CNT@SnO 2 @PPy electrode exhibits excellent rate capability and high capacity retention with a reversible capacity of 226 mAh g −1 after 100 cycles at the current density of 100 mA g −1 . The improved electrochemical performance may be assigned to the synergistic effects among CNT, SnO 2 , and PPy . It may enhance electrical conductivity, avoid the pulverization of electrode material, and prevent the aggregation of Sn during the charge/discharge processes.