A spray-freezing approach to reduced graphene oxide/MoS2 hybrids for superior energy storage

Author: Cheng, T., Xu, J., Tan, Z. Q., Ye, J. L., Tao, Z. C., Du, Z. Z., Wu, Y., Wu, S. L., Ji, H. X., Yu, Y., Zhu, Y. W.

Journal: Energy Storage Materials

DOI:  10.1016/j.ensm.2017.07.001

Keywords: Reduced graphene oxide, Molybdenum disulfide, Lithium ion batteries, Sodium ion batteries, Electrochemistry, high-performance lithium, excellent electrochemical performance, na-ion batteries, few-layer mos2, binder-free, high-capacity, nanosheets

Abstract: 

A three-dimensional (3D) architectural hybrid, composed of reduced graphene oxide (RGO) and ultrathin MoS2 layers, is fabricated by a facile spray-freezing method. The spray-freezing to liquid nitrogen rapidly freezes the precursor droplets which avoids phase separation and restacking of MoS2 and RGO platelets, and the following drying/annealing results in the porous 3D structure. The as-prepared 3D architectural RGO/MoS2 hybrid has a high surface area of 128 m(2) g(-1), a porous structure and a good electrical conductivity. In LIBs, the capacity of RGO/MoS2 anode (with an optimized MoS2 content of 55 wt%) remains 1197 mAh g(-1) after 400 cycles of measurement at a current density of 1 A g(-1) and it remains 892 mAh g(-1) over 400 cycles at a current density of 2 A g(-1). A capacity of 723 mAh g(-1) is obtained at a current of 10 A g(-1). As for the anode (with an optimized MoS2 content of 74 wt%) in SIBs, a high initial discharge capacity of 1315 mAh g(-1), a superior rate capacity of 470 mAh g-(1) at 1 A g(-1) and an excellent cycling stability (518 mAh g(-1) after 200 cycles at 0.5 A g(-1)) are demonstrated.