It is highly important to develop high-performance sulfur cathode to solve low areal sulfur loading, shuttling and sluggish conversion of polysulfides for lithium-sulfur batteries. Herein, a three-dimensional (3D) freestanding framework configured with Co nanoparticles and Co-N_x codoped carbon nanotubes anchored in a carbon foam is synthesized and investigated as a new type of sulfur host. Such an architecture can serve not only as a conductive carbon networks but also as host scaffold for high sulfur-containing electrodes. The hierarchical porous structures cooperated with high density and dispersion multifunctional Co-N_x species can efficiently trap and manipulate catalytic conversion kinetics of polysulfides. Benefiting from above characteristics, the designed cathodes exhibit a high capacity (1259 mA h g⁻¹) at 0.1 C and excellent cycling performance with an ultralow decay of 0.038% per cycle over 500 cycles at a high current density of 3 C. Even with a high sulfur loading (7.0 mg cm⁻²) and lean electrolyte (E/S = 5 μL mg⁻¹) operation, a high areal capacity of 4.34 mA h cm⁻² is still achieved after 100 cycles at 0.1 C. This work provides a low-cost route for preparation of freestanding cathode materials toward highly efficient lithium-sulfur batteries.

开发高性能硫正极以解决锂硫电池多硫化物的低面积硫负载、穿梭和转化缓慢的问题。在此，合成并研究了一种由 Co 纳米颗粒和 Co-N _x共掺杂碳纳米管固定在碳泡沫中的三维 (3D) 独立框架，并作为一种新型的硫主体进行了研究。这种结构不仅可以作为导电碳网络，还可以作为高含硫电极的主体支架。分层多孔结构与高密度分散多功能Co-N _{x 配合}物种可以有效地捕获和操纵多硫化物的催化转化动力学。受益于上述特性，所设计的正极在 0.1 C 下表现出高容量（1259 mAh g ^-1）和优异的循环性能，在 3 C 的高电流密度下超过 500 次循环，每个循环的衰减仅为 0.038%。高硫负载 (7.0 mg cm ^-2 ) 和贫电解质 (E/S = 5 μL mg ^-1 ) 操作，在 0.1 C 下循环 100 次后仍可实现4.34 mAh cm ^-2的高面积容量。这项工作提供一种用于制备高效锂硫电池的独立正极材料的低成本途径。