Synthesis of N-doped carbon-coated Zn–Sn mixed oxide cubes/graphene composite with enhanced lithium storage properties

Abstract

Developing the superior electrode materials with large reversible capacity, excellent rate capability and long cycling stability for high-performance lithium-ion batteries (LIBs) is highly desirable for electric vehicles and hybrid electronic vehicles. Herein, three-dimensional N-doped carbon (NC)-coated Zn–Sn mixed oxide (ZTO) cubes dispersed on reduced graphene oxide (ZTO@NC/RGO) composite are synthesized via a facile strategy combined with the hydrothermal treatment and carbonization of conductive polypyrrole. In this unique architecture, the ultrathin NC shells are interconnected through RGO and construct a continuous 3D conductive network, which provides a very efficient channel for electron transport. Furthermore, the flexible and high-conducting reduced graphene oxide and carbon shells can accommodate the mechanical stress induced by the volume change of ZTO cubes during lithiation as well as prohibit the aggregation of ZTO cubes, which would maintain the structural and electrical integrity of the ZTO@NC/RGO electrode during the lithiation/delithiation processes. Benefiting from the advantages of intrinsic architecture, as LIBs anodes, ZTO@NC/RGO exhibits enhanced lithium storage properties, delivering a large specific capacity of 732.8 mAh g−1 at a current density of 100 mA g−1 after 50 cycles, and presenting good rate capability.