Lithium sulfur batteries (LSBs) draw extensive interest because of the ultra-high capacity and low material cost. However, the sluggish lithium polysulfides (LIPSs) conversion processes are detrimental to cycle stability and rate capability, inhibiting the commercial application of LSBs. Here we present the well-designed FeCo alloy catalysts anchored on porous carbon (FeCo-C) as sulfur host to improve the electrochemical performance by accelerating the conversion reactions. The FeCo alloy demonstrates high catalytic effect and strong adsorption capability of LIPSs, in which potential polarization can be greatly decreased and “shuttle effects” can be largely avoided. As a result, the obtained S/FeCo-C composites show an initial specific capacity of 791.9 mAh g⁻¹ at a large current density of 2 C and maintain 502.5 mAh g⁻¹ even after 500 cycles. Moreover, 720 mAh g⁻¹ (corresponding to 70% retention) can be achieved after 100 cycles at 0.2 C with a high sulfur content of 80 wt%, enabling high sulfur utilization. This work not only provides a new insight to investigate the conversion kinetics of LiPSs, but also opens up a new avenue for advanced lithium sulfur batteries.

锂硫电池（LSB）的超高容量和较低的材料成本引起了广泛的关注。然而，缓慢的多硫化锂（LIPS）转化过程不利于循环稳定性和速率性能，从而抑制了LSB的商业应用。在这里，我们介绍设计良好的FeCo合金催化剂，该催化剂以硫为主体锚固在多孔碳（FeCo-C）上，通过加速转化反应来改善电化学性能。FeCo合金显示出LIPS的高催化作用和强大的吸附能力，其中LIPS的电位极化可以大大降低，而“穿梭效应”则可以避免。结果，所获得的S / FeCo-C复合材料显示出791.9mAh g ^-1的初始比容量。在2 C的大电流密度下，即使经过500次循环也保持502.5 mAh g ^-1。此外，在0.2C下100个循环之后，在具有80wt％的高硫含量的情况下，可以实现720mAh g ^-1（对应于70％的保留）。这项工作不仅为研究LiPS的转化动力学提供了新的见解，而且还为高级锂硫电池开辟了一条新途径。