Anchoring nanoarchitectonics of 1T’-MoS2 nanoflakes on holey graphene sheets for lithium-ion batteries with outstanding high-rate performance

Abstract

Rapid charging is of high demand in lithium-ion batteries (LIBs). Molybdenum sulfide (MoS2) has attracted great interest as a potential anode for LIBs due to its high theoretical capacity. However, low electronic conductivity and severe volume change upon lithiation/delithiation hinder its applications, especially in high-rate applications. Herein, we develop a facile assembly process to fabricate a highly conductive 1T’-MoS2/rhGO composite where rhGO is referred as reduced holey graphene oxide. The abundant oxygen-containing groups on holey graphene make it possible for realizing 2D/2D assembly of 1T’-MoS2 with graphene oxide. When used in LIBs, the 1T’-MoS2/rhGO anode delivered a high specific capacity of 1084 mAh g−1 at 0.2 A g−1 and outstanding high-rate performance, 635 mAh g−1 at a large current density of 5 A g−1 for 2000 cycles with capacity retention reaching 94.5%. The excellent high-rate performance is attributed to the synergic effects of the metallic 1T'-MoS2 and the holey graphene matrix. The former increases the overall conductivity while the latter anchors 1T'-MoS2 nanoflakes tightly through chemical bonding, thus preventing volume changes during cycling. This facile approach for achieving 2D and 2D assembly paves a new way of developing high-rate performance anodes for LIBs which can better fulfill the demand for fast-charging technology.