Electrochemical Behavior Promotion of Polysulfides by Cobalt Selenide/Carbon Cloth Interlayer in Lithium−Sulfur Batteries

Abstract

LithiumÀ sulfur batteries have been regarded as the next generation of competitive batteries because of their high theoretical capacity and energy density. However, the commercial development of lithiumÀ sulfur batteries is restricted by the shuttle action of polysulfides and volumetric expansion of sulfur. Herein, we developed cobalt selenide/carbon cloth composites (CoSe 2 /CC) as the interlayer. CoSe 2 can not only limit the shuttling of polysulfides by CoÀ S bonds and accelerate the catalytic conversion kinetics of sulfur chemistry, but also increases the electrical conductivity of materials, leading to an excellent cycle stability. As a result, the cell with CoSe 2 /CC interlayer has a high initial capacity of 1420 mAh g À 1 at 0.1 C and keeps high-capacity retention of 596 mAh g À 1 after 500 cycles at 1 C rate (70 %). Subsequent electrochemical tests show that CoSe 2 /CC enhance the electrochemical behavior of the polysulfides. Therefore, the hierarchical CoSe 2 /CC composites have promising application potential in lithiumÀ sulfur batteries.

Recent advances in modified commercial separators for lithium–sulfur batteries

“…However, metal selenides boast greater electrical conductivity due to looser valence electrons and greater defect density. 340 Zhang et al 341 synthesized ZnSe nanoparticles using ZIF-8 MOF as a template. The highly structured ZnSe nanoparticles showed excellent chemisorption of LiPSs, indicated by nearly transparent UV-vis absorbance.…”

Advanced preparation and application of transition metal selenides in lithium–sulfur batteries: a review

“…In addition to the preparation of fiber membranes by electrospinning, it is also a good choice to modify the carbon cloth by hydrothermal reaction as battery interlayers due to some merits including a short preparation process and in situ reaction. For example, Ren et al 105 fabricated a carbon cloth interlayer (CoSe 2 /CC) of sheet-like CoSe 2 crystals by a two-step hydrothermal method. The large specific surface area and high porosity of CoSe 2 /CC composites facilitated physical adsorption and exposed more active sites to increase the contact area for effectively absorbing LiPSs, and its 3D conductive network structure was beneficial for electron transport.…”

In Situ Growth of NiCoSe Nanoparticles/Holey Carbon Nanosheet on Carbon Cloth as an Efficient Sulfur Host for Flexible Li–S Batteries

“…can anchor LiPSs through chemisorption and effectively inhibit the "shuttle effect." [18][19][20][21][22] Transition metal selenide sulfur hosts have garnered significant attention due to the similar physical and chemical properties between sulfur and selenium, [23][24][25][26] and the bimetallic metal selenides have been extensively investigated since they can offer more adsorption active sites than single metal selenides. 27,28 As a successful example, Zhang et al synthesized a sea urchin-like NiCo 2 Se 4 (u-NCSe) and loaded it with sulfur, which exhibited high capacities (1330 and 626 mA h g −1 at 0.1C and 5C rates).…”