Facile Microwave-Impulse Synthesis of Multifunctional rGO/MoS₂/MoO₂ Composites as a Permselective Separator-Coating Layer for Li–S Batteries

Abstract

The commercial applications of Li–S batteries (LSBs) can be expanded by the development of shuttle effect-prohibiting multifunctional materials using high-efficiency and energy-saving methods. Here, we report a facile microwave-impulse-based method to synthesize multifunctional rGO/MoS2/MoO2 heterostructure characterized with lamellar MoS2/MoO2 heterojunctions attached to reduced graphene oxide (rGO) sheets. Microwaves can directly work on the precursor materials, and the preparation process can be completed in only 100 s. The rGO/MoS2/MoO2 composite could give strong chemisorption ability and excellent catalytic activity of lithium polysulfides (LPSs) while maintaining a relatively high conductivity from the rGO matrix. Moreover, permselective rGO/MoS2/MoO2 layers with numerous micron-size pores can trap polysulfide anions while promoting the diffusion of Li+, which is of great significance in efforts to improve the cycling stability and reaction kinetics of LSBs. A cell with an rGO/MoS2/MoO2-coated separator retains 62.1% of its capacity with a 0.12% capacity decay per cycle over 300 cycles at 0.5C. This work offers an innovative route for the rapid preparation of multifunctional separators for LSBs.

A new synthesis approach of hierarchical MoS2 nanoflakes toward hydrogen evolution in both acidic and alkaline media

“…To address this problem, microwave heating can provide an efficient and homogeneous reaction condition via ''internal heating'', involving enhanced reaction rates, selectivity and product yields. [17][18][19] Furthermore, the ultrasound-assisted methods were reported for the preparation of ultrathin MoS 2 flakes to replace chemical exfoliated MoS 2 with lithium intercalation using butyllithium in hexane solution. The ultrasonic cavitation phenomena in liquid at the moment of ultrasonic emission will generate a large number of tiny bubbles (the socalled ''bubble effect''), and subsequently the bubbles break up in an instant to produce local high temperature and pressure for the nucleation and growth of the crystal nucleus.…”

MoO2/t-C3N4 Heterogeneous Materials with Bidirectional Catalysis for the Rapid Conversion of S Species in Li–S Batteries

“…Two binding energy peaks appear in the XPS spectrum of the O 1s orbital (Figure d), representing two chemical bonds, namely, O–Mo (529.49 eV) and C–O–Mo (531.8 eV). The formation of the C–O–Mo chemical bond demonstrates the successful preparation of the heterostructure, which is important for accelerating the reaction kinetics of the LiPSs conversion. , Two different peaks at 284.8 and 287.7 eV, caused by to C–O–Mo and N–C=N, are visible in the XPS spectra of the C 1s orbital (Figure e). ,, This again demonstrates the formation of heterogeneous structures and the successful preparation of carbon nitride.…”

Promoting the application of sulfur electrodes in lithium sulfur batteries: a review about the optimization

“…Zhao et al A simpler method based on microwave pulses is proposed, which can synthesize the special structure of multifunctional rGO/MoS 2 /MoO 2 , with a cell with an rGO/MoS 2 /MoO 2 coated diaphragm maintaining 62.1% capacity over 300 cycles at 0.5C, during continuous cycling, the capacity decays with a corresponding decay rate of 0.12% (Fig. 1c) [12]. Song et al The research led to the development of a VN-modified separator that is capable of functioning as a control LiPS device [13].…”