Preparation of GO/Diatomite/Polyacrylonitrile Functional Separator and Its Application in Li–S Batteries

Abstract

Lithium–sulfur (Li–S) batteries have received extensive attention due to their numerous advantages, including a high theoretical specific capacity, high energy density, abundant reserves of sulfur in cathode materials, and low cost. Li–S batteries also face several challenges, such as the insulating properties of sulfur, volume expansion during charging and discharging processes, polysulfide shuttling, and lithium dendritic crystal growth. In this study, a composite of a porous multi-site diatomite-loaded graphene oxide material and a PAN fiber membrane is developed to obtain a porous and high-temperature-resistant GO/diatomite/polyacrylonitrile functional separator (GO/DE/PAN) to improve the electrochemical performance of Li–S batteries. The results show that the use of GO/DE/PAN helps to inhibit lithium phosphorus sulfide (LPS) shuttling and improve the electrolyte wetting of the separator as well as the thermal stability of the battery. The initial discharge capacity of the battery using GO/DE/PAN is up to 964.7 mAh g−1 at 0.2 C, and after 100 cycles, the reversible capacity is 683 mAh g−1 with a coulombic efficiency of 98.8%. The improved electrochemical performance may be attributed to the porous structure of diatomite and the layered composite of graphene oxide, which can combine physical adsorption and spatial site resistance as well as chemical repulsion to inhibit the shuttle effect of LPS. The results show that GO/DE/PAN has great potential for application in Li–S batteries to improve their electrochemical performance.

ARGET-ATRP-Mediated Grafting of Bifunctional Polymers onto Silica Nanoparticles Fillers for Boosting the Performance of High-Capacity All-Solid-State Lithium–Sulfur Batteries with Polymer Solid Electrolytes

“…However, in conventional liquid-state LIB systems, the favorable solubility of lithium polysulfides (LiPSs) generated at the cathode during battery cycling leads to continuous loss of active materials in the cathode [ 8 , 9 , 10 , 11 , 12 ]. These soluble LiPSs (Li 2 S x , 4 < x < 8) migrate to the anode side with the electrolyte, a phenomenon known as the “shuttle effect”, where they react with the lithium metal, forming insoluble Li 2 S 2 and Li 2 S, which subsequently deposit on the lithium metal surface [ 13 , 14 , 15 ]. This seemingly promising cathode material simultaneously gives rise to the aforementioned issues on both the cathode and anode, resulting in rapid capacity decay of Li-S batteries.…”