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

Lithium-sulfur batteries (LSBs) are a class of new-generation 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 MoS2, 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 MoS2, 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.

Automated summary

Hierarchical porous carbon nanonet flakes decorated with MoS2 effectively address the issues of LiPS dissolution and shuttling in lithium-sulfur batteries, providing high performance and stability.