Sandwiched Cathodes Assembled from CoS₂‐Modified Carbon Clothes for High‐Performance Lithium‐Sulfur Batteries

Abstract

Structural design of advanced cathodes is a promising strategy to suppress the shuttle effect for lithium‐sulfur batteries (LSBs). In this work, the carbon cloth covered with CoS2 nanoparticles (CC‐CoS2) is prepared to function as both three‐dimensional (3D) current collector and physicochemical barrier to retard migration of soluble lithium polysulfides. On the one hand, the CC‐CoS2 film works as a robust 3D current collector and host with high conductivity, high sulfur loading, and high capability of capturing polysulfides. On the other hand, the 3D porous CC‐CoS2 film serves as a multifunctional interlayer that exhibits efficient physical blocking, strong chemisorption, and fast catalytic redox reaction kinetics toward soluble polysulfides. Consequently, the Al@S/AB@CC‐CoS2 cell with a sulfur loading of 1.2 mg cm−2 exhibits a high rate capability (≈823 mAh g−1 at 4 C) and delivers excellent capacity retention (a decay of ≈0.021% per cycle for 1000 cycles at 4 C). Moreover, the sandwiched cathode of CC‐CoS2@S/AB@CC‐CoS2 is designed for high sulfur loading LSBs. The CC‐CoS2@S/AB@CC‐CoS2 cells with sulfur loadings of 4.2 and 6.1 mg cm−2 deliver high reversible capacities of 1106 and 885 mAh g−1, respectively, after 100 cycles at 0.2 C. The outstanding electrochemical performance is attributed to the sandwiched structure with active catalytic component.

A review on theoretical models for lithium–sulfur battery cathodes

“…Considering the favorable catalytic properties of CoS 2 , a sandwiched cathode composed of carbon clothes modified by CoS 2 was designed. 116 It confirms from theoretical simulations that large negative Gibbs free energy on the surface of cathodes is responsible for the high catalytic activity (Figure 8C). Su et al also employed theoretical models to explain the improved reaction thermodynamics by the Fe 3 O 4 /CNSs-PP separator as well.…”

Multisize CoS2 Particles Intercalated/Coated‐Montmorillonite as Efficient Sulfur Host for High‐Performance Lithium‐Sulfur Batteries

“…For the cathodes before charge-discharge cycling, each plot consists of a semicircle at the high frequency related to the charge transfer resistance (R ct ) and an inclined line at the low frequency corresponding to the ion diffusion resistance (R s ). [18] The R ct value of the S/CoS 2 @MMT-10 cathode (29 Ω) is close to that of the S/CoS 2 cathode (25 Ω) and much smaller than that of the S/MMT cathode (162 Ω), indicating that CoS 2 endows the CoS 2 @MMT-10 composite with high electrical conductivity. Thus, the CoS 2 @MMT-10 composite can promote local and overall electron transport in the composite cathodes and improve the sulfur utilization.…”

“…Yuan et al investigated the catalysis effect of CoS 2 in promoting the LiPSs redox reactions via micrometer-sized CoS 2 particles for the first time. [13] More recently, CoS 2 with different structures and morphologies were further developed for use in LiÀ S batteries in related works, [14][15][16][17][18] among which CoS 2 was mostly combined with porous carbon materials. It was found that the incorporation of these CoS 2 particles did enhance the reaction kinetics and cycling performance of LiÀ S batteries.…”

Energy-Saving Synthesis of Functional CoS2/rGO Interlayer With Enhanced Conversion Kinetics for High-Performance Lithium-Sulfur Batteries

“…As shown in Figure 2E , the Co 2p 1/2 and Co 2p 3/2 characteristic peaks of CoS 2 were located at 794.4 and 779.4 eV in the HR-XPS of Co 2p, respectively. ( Xu, et al, 2021 ). The satellite peak signal is 781.8, 786.1, 797.5, and 803.4 eV ( Wang, et al, 2018 ).…”