Linear-PEI-Derived Hierarchical Porous Carbon Nanonet Flakes Decorated with MoS₂ as Efficient Polysulfides Stabilization Interlayers for Lithium–Sulfur Battery

Abstract

Lithium−sulfur batteries (LSBs) are a class of newgeneration high-energy-density rechargeable batteries. However, the persisting issues of lithium polysulfide (LiPS) dissolution and shuttling severely impedes their practical applications. To address this challenge, we synthesized hierarchical porous carbon nanonet flakes (CNNFs) decorated with a small amount of loosely distributed MoS 2 , as an effective interlayer for LiPSs stabilization. Due to the special hierarchical porous structures with large abundant micro-, meso-, and macro-pores derived from the linear-PEI-templated CNNFs and the chemisorption and electrocatalytic effects for MoS 2 , the shuttling of the soluble polysulfides intermediates is efficiently alleviated, accompanied by a stabilized Li + transportation pathway for the cell. A high initial capacity of 1413.8 mA h•g −1 at 0.1 C and a stable capacity of 897.5 mA h•g −1 at 0.5 C after 200 cycles are obtained, corresponding to a capacity decay rate of 0.063% per cycle. Moreover, after 500 cycles at 1 C, a discharging capacity of 515.7 mA h g −1 with a Coulombic efficiency of 98.7% can be obtained. The trapping of polysulfides and the synergistic maintenance of electron and ion pathway can provide an effective stabilization strategy for high-performance lithium−sulfur battery.

Overview of the Latest Developments and Perspectives about Noncarbon Sulfur Host Materials for High Performance Lithium–Sulfur Batteries

“…Transition metal nitrides can exhibit excellent performance as a novel type of cathode material for Li–S batteries. Herein, Mosavati et al expanded their research to a series of metal nitrides of tungsten nitride (WN), molybdenum nitride (Mo 2 N), and vanadium nitride (VN), , which acted together with sulfur to be used as new cathode host materials for Li–S batteries. It is observed that WN has higher electrochemical performance than VN and Mo 2 N, mainly because sulfur can remain on the surface of the electrode due to the strong reversible reaction between nitrides and LiPSs, and it can also reduce the loss of active material and the reduction of specific surface area.…”

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

“…Based on the above mechanism, a lot of studies have been conducted and various methods have been adopted such as improving the sulfur electrode host materials, 25,26 designing modified separators, 27,28 inserting interlayers, 29,30 optimizing the electrolyte, 31,32 and using novel and strong binders. 33,34 These methods enable the enhancement of the adsorption and conversion of LiPSs during the charge and discharge processes, inhibit the shuttle effect of LiPSs and accelerate the transfer rate of ions and electrons.…”

“…Based on the above mechanism, a lot of studies have been conducted and various methods have been adopted such as improving the sulfur electrode host materials, 25,26 designing modied separators, 27,28 inserting interlayers, 29,30 optimizing the electrolyte, 31,32 and using novel and strong binders. 33,34 Fig.…”

Superior polysulfide adsorption ability by using Ti3C2 nanosheets as effective reservoirs for high electrochemical performance

“…Much effort has been devoted to the study of lithium-sulfur batteries because of their high energy density, long cycle life, and low cost; this technology could be applied in many areas, such as electric vehicles and other electric applications. [1][2][3][4][5] However, the low utilization of their active materials greatly inhibits the commercial application of lithium-sulfur batteries. This is due to their poor electronic conductivity, their polysulfide dissolution, and the shuttle effect that takes place during the electrochemical cycles.…”