Sulfur/nitrogen dual-doped three-dimensional reduced graphene oxide modified with mesoporous TiO2 nanoparticles for promising lithium-ion battery anodes

Abstract

Abstract Three-dimensional graphene is often used as electrode materials due to its excellent electrochemical properties. In this work, sulfur/nitrogen dual-doped reduced graphene oxide (SNG) foam is prepared by a simple sol-gel method with l -cysteine. Furthermore, mesoporous dioxide-titanium (TiO2) nanoparticles are deposited on the surface of SNG at 60 °C to improve the Li+ ions diffusion kinetics. As an anode material for lithium ion batteries, the SNG/TiO2 has an excellent reversible discharging capacity (444 mAh g−1, 0.1 A g−1) and good rate capability (217 mAh g−1, 2.0 A g−1). In addition, the SNG/TiO2 electrode delivers a specific capacity as high as 148.8 mAh g−1 at a current density of 1.0 A g−1 after 1000 cycles, and even at a high current density of 5.0 A g−1, a reversible capacity of 99 mAh g−1 can also be achieved. Hence, the SNG/TiO2 composite synthesized by a simple template-free method at a low-temperature is a promising anode material for lithium ion batteries.