Graphene induced growth of Sb2WO6 nanosheets for high-performance pseudocapacitive lithium-ion storage

Abstract

Abstract Transition metal oxides with the Aurivillius structure have been studied as electrode materials in lithium-ion batteries (LIBs) owing to their high capacity and proper redox voltage. With the opened Aurivillius structure, the antimony tungstate (Sb2WO6, SWO) constituted of {Sb2O2}2n+ and {WO4}2n− is rarely used as negative electrode material for lithium-ion batteries. Herein, the SWO nanosheets/reduced graphene oxide (rGO) hybrid clusters were synthesized, and their electrochemical performances, kinetics and lithium storage mechanism were systematically studied as negative electrode materials for LIBs. Results show that the graphene oxide (GO) not only restricts the growth of layered-structure SWO, but also induces SWO growth along (002) lattice plane and changes SWO particles to SWO nanosheets. The strong interaction between SWO nanosheets and rGO greatly improve conductivity and structure stability of SWO nanosheets/rGO hybrid clusters, which also can efficiently alleviate agglomeration and volume change of SWO nanosheets during cycling. Meanwhile, the dominating pseudocapacitive contribution (78.2% at 0.8 mV s−1) effectively enhanced the electrochemical performance. As an anode material for LIBs, the SWO nanosheets/rGO hybrids deliver a high specific capacity of 1141 mAh g−1 at a current density of 0.2 A g−1, and their specific discharge capacity is 595 mAh g−1 after 130 cycles at 0.2 A g−1. This work demonstrates that the SWO nanosheets/rGO hybrid clusters are a promising negative electrode material for high-energy-density LIBs.