Atomically dispersed Fe in a C₂N Based Catalyst as a Sulfur Host for Efficient Lithium–Sulfur Batteries

Abstract

Lithium–sulfur batteries (LSBs) are considered to be one of the most promising next generation energy storage systems due to their high energy density and low material cost. However, there are still some challenges for the commercialization of LSBs, such as the sluggish redox reaction kinetics and the shuttle effect of lithium polysulfides (LiPS). Here a 2D layered organic material, C2N, loaded with atomically dispersed iron as an effective sulfur host in LSBs is reported. X‐ray absorption fine spectroscopy and density functional theory calculations prove the structure of the atomically dispersed Fe/C2N catalyst. As a result, Fe/C2N‐based cathodes demonstrate significantly improved rate performance and long‐term cycling stability. Fe/C2N‐based cathodes display initial capacities up to 1540 mAh g−1 at 0.1 C and 678.7 mAh g−1 at 5 C, while retaining 496.5 mAh g−1 after 2600 cycles at 3 C with a decay rate as low as 0.013% per cycle. Even at a high sulfur loading of 3 mg cm−2, they deliver remarkable specific capacity retention of 587 mAh g−1 after 500 cycles at 1 C. This work provides a rational structural design strategy for the development of high‐performance cathodes based on atomically dispersed catalysts for LSBs.

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

“…This observation reveals the CC‐CoS 2 has the better catalytic activity, which enables the more efficient utilization of lithium polysulfides. [ 67 , 68 , 69 ] The potentiostatic Li 2 S dissolution tests were also performed (Figure 4c , d ). The CC‐CoS 2 cell exhibits a much larger dissolution capacity (143 mAh g −1 ) than the CC cell (117 mAh g −1 ).…”

Tubular CoFeP@CN as a Mott–Schottky Catalyst with Multiple Adsorption Sites for Robust Lithium−Sulfur Batteries

“…Compared with LIBs, LSBs are characterized by a sixfold higher theoretical energy density, 2600 W h kg −1 , and a potentially lower cost and environmental impact if properly selecting the cathode materials. [1][2][3] Despite these attractive advantages, the electrically insulating character of sulfur and the shuttle effect of intermediate lithium polysulfides (LiPS) greatly limit the practical application of LSBs. [4] Additionally, the serious volume changes and slow redox kinetics during the charging/discharging process also reduce the cycling life and power density.…”

Defect Engineering for Expediting Li–S Chemistry: Strategies, Mechanisms, and Perspectives

“…[152] In this sense, SACs that harness abundant adsorption sites and robust electrochemical activities are regarded as an appropriate candidate to capture and catalyze PS and hence suppress the "shuttle effect" in Li-S batteries. [153][154][155][156][157][158] In this section, prevailing synthetic strategies and characterization tools of SACs are introduced to aid the identification of such mediators. The roles of SACs played in Li-S batteries are also covered to reflect the fundamental understanding and practical implementation in this emerging direction.…”