Sulfur-Implanted Carbon Dots-Embedded Graphene As Ultrastable Anode For Li-Ion Batteries

Sulfur doping in carbonaceous materials is an effective approach to improve the performance of Li-ion batteries (LIBs). Herein, sulfur-implanted carbon dots-embedded graphene (S-CDs/rGO) as an anode material for LIBs is reported. A facile method is used to prepare S-CDs/rGO by annealing the mixture of benzyl disulfide (BDS) and graphene oxide (GO). Herein, BDS serves as both the sulfur source and precursor of CDs. S-CDs/rGO as an anode material for LIB delivers initial specific capacities of 938.8 mAh g(-1) (first cycle) and 598.6 mAh g(-1) (second cycle) at a current density of 100 mA g(-1). S-CDs/rGO exhibits superior cycling performance with good capacity retentions of 78.8% (500 cycles), 61.5% (2000 cycles), and 75.7% (2000 cycles) at higher current densities of 1000, 2000, and 3000 mA g(-1), respectively. Moreover, the full cell assembly of the prepared S-CDs/rGO as an anode and commercial LiFePO4 as a cathode in the voltage range of 1.5-3.9 V delivers a high reversible capacity of 203.3 mAh g(-1) after extensive 1000 cycles at 500 mA g(-1) with 51.8% retention (a low fading rate of 0.049% per cycle), rendering it as a promising anode material for application in high-performance LIBs.