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Lithium–sulfur (Li–S) batteries are widely regarded as the most promising batteries for the future due to their higher specific capacity and lower prices. Various strategies are utilized to alleviate the shortcomings of Li–S batteries failing to reach theoretical capacity. However, basic research at the molecular level continues to be lacking. Therefore, we use molecular dynamics to study the details of the solvated structure of Li–S batteries electrolyte and the nature of the transport process, revealing the relationship between the solvated structure of the electrolyte of LiPF6 and the organic solvent ethylene carbonate/dimethyl carbonate (EC/DMC). The electrolyte of Li2S4 was first simulated in a pure solvent environment. Then the LiPF6 salt was added to the model to simulate a typical electrolyte for a working Li–S battery. Regarding the rationality of the solvent system, various reference systems such as density, dielectric constant, viscosity and diffusion coefficient of the solvent were used for verification. And the detailed composition of the first solvation shell of the polysulfate ion and the coordination number of the ions are discussed. These results provide new insights into the use of EC/DMC electrolytes in Li–S batteries, while at the same time providing a basis for efficient future predictions of electrolyte structure and transport in complex electrode confinements. The radius of the first solvation shell of each component is the PF 6 − anion at about 0.22–0.28 nm, the DMC solvent at about 0.32–0.36 nm and the EC solvent at about 0.41 nm, respectively. The first solvation shell according to these distributions has a radius of about 0.5 nm. The coordination number in the first solvation shell is plotted, which is about 1.88 for PF 6 − , 1.86 for DMC, and about 0.14 for EC. In conclusion, 3.88 molecules are produced in the first solvation shell of the ion. [ABSTRACT FROM AUTHOR]

Poly(3-methylthiophene)/reduced graphene oxide (P3MT/RGO) modified glassy carbon electrode (GCE) was fabricated via a facile procedure. P3MT was directly electrodeposited on the RGO coated electrode and employed for the electrochemical detection of paracetamol (PCT). The morphology of composite was characterized by scanning electron microscopy (SEM). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to investigate the electrochemical behaviors of PCT on P3MT/RGO/GCE. Experimental parameters, such as the scan rates, polymerization laps and the pH of buffer solution were optimized. Under the optimal conditions, the anodic peak current in DPVs varies linearly with the concentration of PCT, and the limit of detection was 0.025 μ M. Moreover, the proposed P3MT/RGO/GCE also exhibited superior stability and reproducibility. The poly (3-methylthiophene)/reduced graphene oxide (P3MT/RGO) material was firstly proposed for the fast, sensitive electrochemical determination of paracetamol (PCT). The RGO can efficiently provide abundant reaction sites and promote the electron transfer, while the P3MT was electrodeposited on the surface of RGO/GCE. The redox current response increased further and the reversibility of the redox reaction was improved. The developed sensor showed excellent stability, high selectivity, low detection limit and good applicability in real samples. [ABSTRACT FROM AUTHOR]