Two-dimensional sulfur-doped Mn3O4 quantum dots/reduced graphene oxide nanosheets as high-rate anode materials for lithium storage

Abstract

Herein, a two-dimensional sulfur-doped Mn3O4 quantum dots/reduced graphene oxide (S-Mn3O4-QDs/rGO) nanosheets are prepared via in-situ sulfidation doping process in a water/ethanol mixed solvent. The 2D nanosheets are made up of ultrafine S-Mn3O4-QDs with a mean diameter of about 5 nm uniformly coated on the surface of rGO. Doping Mn3O4-QDs with sulfur can improve the electrical conductivity of Mn3O4 and increase the specific capacity and rate capability. The strong interaction and synergy effect between S-Mn3O4-QDs and rGO would maintain the integrity of nanosheets and improve the reversibility. As performed as anode materials for lithium-ion batteries, the S-Mn3O4-QDs/rGO anode exhibits a high capacity of 847 mAh g−1 at a current rate of 0.5 A g−1 after 100 cycles, and excellent high-rate capability of up to 443 mAh g−1 at 8 A g−1, which makes it promising as an anode material for high-performance lithium-ion batteries.