Insights into the sandwich-like ultrathin Ni-doped MoS2/rGO hybrid as effective sulfur hosts with excellent adsorption and electrocatalysis effects for lithium-sulfur batteries

The design of sulfur hosts with high conductivity, large specific surface area, strong adsorption and electrocatalytic ability is crucial to advance high performance lithium-sulfur batteries. Herein, a novel ultra-thin sandwich-type Ni-doped MoS2/reduced graphene oxide (denote as Ni-doped MoS2/rGO) hybrid is developed as a sulfur host through a simple one-step hydrothermal route. The two-dimensional layered structure Ni-doped MoS2/rGO hybrid with heterostructure and heteroatom architecture defects not only plays a key role in adsorption of lithium polysulfide but also catalyzes on redox kinetics of sulfur and polysulfide species. Meanwhile, it can contribute to the large specific surface area for Li2S/S-8 deposition, fast Li-ion and electron transportation, thus enhancing the electrocatalytic properties, as confirmed firstly by cyclic voltammetry (CV) results. Due to the adsorption-catalytic synergistic effect, the Ni-doped MoS2/rGO cathode exhibits high specific capacity (1343.6 mA h g(-1) at 0.2 C, 921.6 mA h g(-1) at 1 C), high coulombic efficiency and an outstanding cycle stability (with the low attenuation rate of 0.077% per cycle over 140 cycles at 0.5 C and 0.11% per cycle over 400 cycles at 1 C, respectively). This work proposes some inspiration for exploring the construction of advanced lithium-sulfur batteries through the rational design defects of atomic structure and electronic states of MoS2 as sulfur host. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

A novel ultra-thin sandwich-type Ni-doped MoS2/reduced graphene oxide (Ni-doped MoS2/rGO) hybrid was developed as a sulfur host through a simple one-step hydrothermal route, demonstrating its crucial role in improving the performance of lithium-sulfur batteries. This hybrid material exhibited high specific capacity, high coulombic efficiency, and outstanding cycle stability, providing important insights for exploring advanced lithium-sulfur batteries.