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

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 128m2g−1, a porous structure and a good electrical conductivity. In LIBs, the capacity of RGO/MoS2 anode (with an optimized MoS2 content of 55wt%) remains 1197mAhg−1 after 400 cycles of measurement at a current density of 1Ag−1 and it remains 892 mAh g−1 over 400 cycles at a current density of 2Ag−1. A capacity of 723mAhg−1 is obtained at a current of 10Ag−1. As for the anode (with an optimized MoS2 content of 74wt%) in SIBs, a high initial discharge capacity of 1315mAhg−1, a superior rate capacity of 470mAhg−1 at 1Ag−1 and an excellent cycling stability (518mAhg−1 after 200 cycles at 0.5Ag−1) are demonstrated.