A Heterostructured Gel Polymer Electrolyte Modified by MoS₂ for High-Performance Lithium–Sulfur Batteries

Abstract

In Li−S batteries, the shuttle effect of polysulfide lithium (LiPS) on the cathode side and the growth of lithium dendrites on the anode side are two major problems that lead to an insufficient cycle life. Herein, in light of the challenges brought on by the different chemical environments on both sides of Li−S batteries, a heterostructured poly(ethyl acrylate-co-ionic liquid) gel electrolyte with a single-sided electrocatalytic reduced graphene oxide/MoS 2 coating (MoS 2 @rGO-GPE) was developed in order to assemble a high-performance Li−S battery with a self-supporting graphene sulfur cathode. In such a device architecture, there is multiposition suppression of the shuttle effect; that is, the confinement of the graphene foam, the catalysis of the MoS 2 composite, and the capture of the gel polymer electrolyte. Our results show that the ionic conductivity of the heterostructured electrolyte is 1.98 mS cm −1 , and the Li ion transference number reaches 0.81. The assembled lithium−sulfur battery displays a high initial discharge capacity of 1027 mAh g −1 at 0.1 C, superior cycle stability (80% capacity retention after 500 cycles), and excellent rate performance. This design strategy provides a valuable route for the development of high-performance lithium−sulfur batteries.

Excitonic Rydberg States in a Trilayer to Monolayer H2-Aided CVD-Grown Large-Area MoS2 Film with Excellent UV to Visible Broad Band Photodetection Applications

“…The Mo 3d spectrum of MAr in Figure a shows two strong peaks at around 229.7 and 232.8 eV, which are attributed to the 3d 5/2 and 3d 3/2 doublet of the 2H phase of Mo 4+ , respectively . The small peak at 226.8 eV corresponds to the 2s core level of S . A very small amount of MoO x is also present in the higher binding energy side as shown in Figure a,d (pink area).…”

“…Thus, it is evident that more S vacancies are present in MArH10 but are passivated. Figure b shows the S 2p 3/2 and S 2p 1/2 doublet at 162.5 and 163.65 eV associated with sulfide (S 2– ) ions in MAr. For MArH10, the doublet spectra of both Mo 3d and S 2p shift toward lower binding energies as shown in Figure d,f, respectively.…”

One action, two benefits: improving the performance of lithium–sulfur batteries with a poly(ionic liquid)

“…3,4 The shuttling of LiPS results in the loss of active substances in the cathode, and its reduction leads to the formation of an insulation layer on the surface of Li metal anode, 5,6 which deteriorate the cycling stability due to the continuously increased interfacial polarization. 7,8 Meanwhile, Li dendrites have high reaction activity. It reacts with liquid electrolyte (LE), which consumes LE continuously, unable to form stable solid electrolyte interface (SEI) layer on the Li anode.…”