Lithium-sulfur batteries, as a next-generation energy storage system, could deliver much higher energy density than traditional lithium-ion batteries. Although many scientific issues have been well solved, the low-cost and green synthesis of the sulfur host to realize efficient electrochemical conversions between polysulfides and sulfur needs more consideration for commercial application. Herein, Co nanocrystal encapsulated in 3D nitrogen-doped mesoporous carbon (Co@NC) is produced in gram-scale via a simple pressure-cooking strategy by using biomass as raw material. The heterogeneous catalyst was featured by an oval morphology consisting of a tremendous amount of mesopores. The Co nanocrystals in the 3D mesoporous carbon could promote the confinement and fast conversion of polysulfides; simultaneously, the 3D hollow oval morphologies could not only substantially relieve the volume change of the cathode part but also enhance the lithium-ion transportation. Consequently, a sulfur cathode within Co@NC with a sulfur loading of 2.5 mg/cm² exhibits significantly improved cycle stability with a fade of 0.17% per cycle over 200 cycles. Our works prove the beneficial effects of heterogeneous catalysis in polysulfide conversion reactions and provide a green, facile, scalable, and low-cost synthetic strategy of advanced hollow carbon monolith for high-performance Li-S batteries.

锂硫电池作为下一代储能系统，可以提供比传统锂离子电池更高的能量密度。尽管已经很好地解决了许多科学问题，但是要实现多硫化物和硫之间高效的电化学转化，硫主体的低成本和绿色合成还需要更多的商业应用考虑。在此，以克级通过以下方式生产封装在3D氮掺杂介孔碳（Co @ NC）中的Co纳米晶体以生物质为原料的简单压力烹饪策略。非均相催化剂的特征是由大量中孔组成的椭圆形形态。3D介孔碳中的Co纳米晶体可以促进多硫化物的封闭和快速转化。同时，3D空心椭圆形不仅可以大大缓解阴极部分的体积变化，而且可以增强锂离子的传输。因此，Co @ NC内的硫阴极的硫负载为2.5 mg / cm ²表现出显着改善的循环稳定性，在200个循环中每个循环的衰减为0.17％。我们的工作证明了多相催化在多硫化物转化反应中的有益作用，并为高性能Li-S电池提供了绿色，便捷，可扩展且低成本的高级空心碳整体材料合成策略。