SnO2 Nanoflake Arrays Coated with Polypyrrole on a Carbon Cloth as Flexible Anodes for Sodium-Ion Batteries

SnO₂ has been extensively studied as an anode material for sodium-ion batteries, which, however, has long been subjected to poor conductivity and large volume expansion accompanied with an unsatisfactory electrochemical performance. Here, novel interlaced SnO₂ nanoflakes are synthesized directly on a carbon cloth collector via hydrothermal and annealing treatment and then coated with polypyrrole (PPy) via electrodeposition. The as-prepared flexible SnO₂@PPy on the carbon cloth exhibits a high initial capacity of 1172.1 mAh g^-1 and an outstanding cycling stability with 85% capacity retention after 300 cycles at 0.1 A g^-1, which can be contributed to the interlaced SnO₂ nanoflakes as well as the coating of PPy. This result shows promising potential for construction of an electrode in high-performance energy storage fields.