Core‐Shell Structure of SnO2@C/PEDOT : PSS Microspheres with Dual Protection Layers for Enhanced Lithium Storage Performance

Abstract

AbstractAbundant material SnO2 is considered as a promising lithium‐ion battery (LIB) anode candidate due to its high theoretical capacity. Yet, the achieved capacity is restricted by the severe cycling degradation. Rational structural design can mitigate the volume expansion of SnO2, improving the structural stability and reaction kinetics at the same time. Herein, core‐shell structured SnO2@C/PEDOT : PSS microspheres are synthesized through a facile approach combined with hydrothermal treatment and polymerization. In the well‐designed architecture, amorphous carbon coated ultrafine SnO2 nanoparticles are aggregated into regular microspheres and wrapped by a PEDOT : PSS layer, forming a robust core‐shell structure with dual protection layers. Such hierarchical structure provides sufficient ion/electron ingress/transport channels, restrains the adverse reaction of the electrolyte, improves the conductivity and buffers the interior stress of the entire electrode, resulting in the stable cycle performance. When evaluated as LIB anode, it demonstrates an initial reversible capacity of 1170.5 mAh g−1 at 0.1 C, maintaining a high capacity of 441.5 mAh g−1 after 1200 stable cycles at high rate of 2 C. The strategy gives a rational avenue to design the oxide anodes with efficient hierarchical structure for LIB development.