Manipulating Electrocatalytic Polysulfide Redox Kinetics by 1D Core–Shell Like Composite for Lithium–Sulfur Batteries

Abstract

Although lithium–sulfur batteries have high theoretical energy density of 2600 Wh kg−1, the sluggish redox kinetics of soluble liquid polysulfide intermediates during discharge and charge is one of the main reasons for their limited battery performance. Designing highly efficient electrocatalysts with a core–shell like structure for accelerating polysulfide conversion is vital for the development of Li–S batteries. Herein, core–shell MoSe2@C nanorods are proposed to manipulate electrocatalytic polysulfide redox kinetics, thereby improving the Li–S battery performance. The 1D MoSe2@C is synthesized via a facile hydrothermal and subsequent selenization reaction. The electrocatalysis of MoSe2 is confirmed by the analysis of symmetric batteries, Tafel curves, changes of activation energy, and lithium‐ion diffusion. Density functional theory calculations also prove the low Gibbs free energy of the reaction pathway and the lithium‐ion diffusion barrier. Therefore, the Li–S batteries using MoSe2 electrocatalyst exhibit an excellent rate performance of 560 mAh g−1 at 1 C with a high sulfur loading of 3.4 mg cm−2 and an areal capacity of 4.7 mAh cm−2 at a high sulfur loading of 4.7 mg cm−2 under lean electrolyte conditions. This work provides a deeper insight into regulation of polysulfide redox kinetics in electrocatalysts for Li–S batteries.

Regulating Polysulfide Conversion Kinetics Using Tungsten Diboride as Additive For High‐Performance Li–S Battery

“…To overcome this energy crisis, robust and superior energy storage devices are required that can helps to increase the interaction with polysulfides. [23][24][25][26][27][28][29][30][31] Such compounds usually contain a metal center (M) along with an anionic part (A). In spite of their ability to bind strongly with the LiPS, these polar compounds still possess a few disadvantages.…”

Ionic‐Liquid‐Assisted Synthesis of FeSe–MnSe Heterointerfaces with Abundant Se Vacancies Embedded in N,B Co‐Doped Hollow Carbon Microspheres for Accelerating the Sulfur Reduction Reaction

“…The high-sulfur-loading electrochemical performances of the developed cells were comparable to those reported in recent studies (Figure 7c and Table S5, Supporting Information). [2,[49][50][51][52][53][54] In addition, pouch cells were also fabricated according to the schematic diagram shown in Figure 7d, delivering an opencircuit voltage of 2.65 V (Figure 7e). Impressively, the Li-S pouch cell assembled using the FeSe-MnSe/NBC/S cathode operating under a higher sulfur loading of 3 mg cm −2 and lean E/S of 8 mL g −1 exhibited an excellent electrochemical performance, delivering an initial specific capacity of 1193 mAh g −1 (3.6 mAh cm −2 ) and favorable cycle stability even after 50 cycles at 0.1 C, which was comparable, and in some cases superior to those of the reported pouch cells (Table S6, Supporting Information).…”

“…The rapid development of electric vehicles and grid-level energy storage technologies has greatly increased the demand for advanced rechargeable batteries that fulfill the criteria of low cost, environmental friendliness, high energy density, and stability. [1,2] Li-S batteries are considered among the most attractive candidates for next-generation energy storage devices due to their considerable energy density of 2600 Wh kg −1 and high theoretical specific capacity of 1675 mAh g −1 . [3][4][5][6] However, the practical application of Li-S batteries is hindered by several issues inherent to the sulfur electrode.…”

A bifunctional VS2–Ti3C2 heterostructure electrocatalyst for boosting polysulfide redox in high performance lithium–sulfur batteries

“…8c and Table S3† exhibit the most critical parameters for the comparison of carbon-based and heterostructure materials as cathode hosts of LSBs. 56,63–82 Note that the introduction of the VS 2 –Ti 3 C 2 host results in higher capacity and the lower capacity decay rate per cycle. This result indicates that VS 2 –Ti 3 C 2 /S electrodes have great advantages to assist LSBs to achieve practical applications.…”