Hierarchical heterojunction structures based-on layered Sb2Te3 nanoplate@rGO for extended long-term life and high-rate capability of sodium batteries

Abstract Three dimensional (3D) hierarchical heterojunction structures were successfully constructed for sodium batteries (SIBs) based on reduced oxidized graphene (rGO) and layered Sb2Te3 nanoplate grown on high electric and flexible copper substrate (Cu@Sb2Te3@rGO). The specific structure can endow electrode material with attractive properties in high-speed charge transfer, fast electronic transport and good stability due to the high conductivity of copper substrate, built-in electric field providing a driving force for charge transfer and the restriction of volume expansion by a 3D hierarchical structure. The binderless and flexible Cu@Sb2Te3@rGO electrode can deliver a superior reversible capacity of 425 mAh g−1 after 200 cycles at a current density of 200 mA g−1, an excellent rate capability of 220 mAh g−1 at 15 A g−1, even a fascinating capacity of 410 mAh g−1 at 2 A g−1 after 1000 cycles. This 3D hierarchical heterojunction structure electrode of Cu@Sb2Te3@rGO can hold great promise for high cycling and rate capacity performance of SIBs.