Carbon-encapsulated 1D SnO2/NiO heterojunction hollow nanotubes as high-performance anodes for sodium-ion batteries

The combination of high-capacity and long cycle stability has always been regarded as a prerequisite for efficient anode materials in sodium-ion batteries (SIBs). In this work, we design and synthesize carbon-encapsulated 1D SnO2/NiO heterojunction hollow nanotubes (SnO2/NiO@C) and successfully apply them as an anode material for SIBs. SnO2/NiO@C is synthesized by a facile electrospinning technique and subsequent chemical bath deposition, followed by polydopamine (PDA) carbonization. The 1D hollow structure can effectively reduce the diffusion length of sodium ions and the large volume variation of SnO2 during cycling. In addition, carbonized PDA is uniformly dispersed on the SnO2/NiO hollow nanotubes, not only contributing to structural stability, but also acting as a conductive matrix to enhance the battery performance. SIBs based on SnO2/NiO@C anodes exhibit a highly reversible capacity of 320 mAh g(-1) after 200 cycles at 100 mA g(-1) and a considerably stable long cycling performance. The present work highlights the potential of SnO2/NiO@C based anode materials for the development of high-performance SIBs with combined high capacity and long cycle stability.