Investigation On The Shuttle Effect Of Polysulfides And The Electrochemical Performance Of Lithium-Sulfur Batteries

Lithium-sulfur?Li-S?battery is a promising next-generation energy storage and conversion device,mainly due to its low cost and high energy density.The ability to suppress the dissolution of lithium polysulfides in liquid electrolyte?LE?that is so-called shuttle effect is an emerging and scientifically challenging,representing an important endeavor toward the successful commercialization of lithium-sulfur?Li-S?battery.Inhabitation of the side diffusion of the polysulfide is the most critical issue in current Li-S battery.In this paper,several methods including solid-state electrolyte,bi-functional separator,interlayer and anodic SEI are therefore introduced to alleviate this problem.Firstly,for the first time,we report a facile in-situ synthesis of pentaerythritol tetraacrylate?PETEA?-based GPE with an extremely high ionic conductivity(1.13×10^-2S cm^-1).Quite intriguingly,this GPE rendered the resulting polymer Li-S battery with a low electrode/GPE interfacial resistance,high rate capacity and improved capacity retention.These remarkable performances can be ascribed to the immobilization of soluble polysulfides imparted by PETEA-based GPE and the construction of a robust integrated GPE/electrode interface.Notably,due to the tight adhesion between the PETEA-based GPE and electrodes,a high-performance flexible polymer Li-S battery was successfully crafted.Moreover,a facile synthesis of an acrylate-based hierarchical electrolyte?AHE?was developed.This quasi-solid electrolyte is assembled by in-situ gelation of a PETEA-based gel polymer electrolyte?GPE?into a polymethyl methacrylate?PMMA?-based electrospun network.The structural similarity and synergetic compatibility between the electrospun network and GPE provide the AHE an ester-rich robust structure with a higher ionic conductivity of 1.02×10^-3 S cm^-1 due to the strong uptake ability and the elimination of commercial separator.First-principle calculations further reveal that the reduced shuttle effect can be attributed to a strong polysulfide anchoring ability of ester functional groups.Subsequently,to enhance the utilization ratio of active sulfur-species and restrain the self-discharge of whole battery,the traditional carbon-based interlayer is equipped with strong polysulfide capturer and appropriated high-voltage component.As well-designed,V₂O₅ fulfilling all the requirements is adopted to decorate the carbon nanofiber interlayer and create a Li-S battery with superior performances.At last,we developed a facile preparation method of an anodic SEI with electrolyte additive InI₃ that can strongly protect the anode from the undesired shuttle effect.The lithium metal and tin oxide anode was protected by the protective layer that uniformly formed on the anode surface as artificial SEI to block the attack of shuttle effect.To sum up,the shuttle effect has been much alleviated with the delicate structural design,stabilized interface and rational materials choice.These works open up new directions for the future development of Li-S batteries and are potential to be promising next-generation energy storage and conversion devices.