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. [ABSTRACT FROM AUTHOR]