Developing high energy density lithium-sulfur (Li–S) batteries mainly relies on the design of the electrode matrix which can accommodate high sulfur loading and still remain high utilization of active materials. Herein, a 3D hierarchical graphitic carbon foam supported graphene@Mo₂C (GCF-G@Mo₂C) heterostructure is introduced as a freestanding electrode for Li–S batteries with a facile and cost-effective method. The N-doped carbon foam wrapped by graphene sheets with agaric-like porous structure could promote fast electron and ion transport, meanwhile effectively anchor the polysulfides through physical confinement and chemical adsorption by strongly polar-polar interactions. More importantly, the Mo₂C nanoparticles can act as the chemical anchoring center to provide strong polysulfide adsorption, as testified by experimental data and first-principle calculations. Moreover, the catalytic effect of Mo₂C also accelerates the redox kinetics of polysulfide conversion, contributing to enhanced rate performance. As a result, the cell with GCF-G@Mo₂C displays an initial capacity as high as 862 mAh g⁻¹ and a retained capacity of 597 mAh g⁻¹ after 600 cycles with only 0.051% capacity fade per cycle at 1C rate, presenting good cycling stability. In addition, the GCF-G@Mo₂C substrate with high sulfur content (70 ​wt%) and sulfur loading (10.5 ​mg ​cm⁻²) achieves an ultra-high areal capacity of 12.6 mAh cm⁻² at 0.1 ​C, offering a competitive cathode for high-performance Li–S batteries.

开发高能量密度锂硫（Li–S）电池主要依靠电极基体的设计，该基体可以容纳高硫负荷，并且仍然保持活性材料的高利用率。在这里，一种3D分层石墨碳泡沫支撑的石墨烯@ Mo ₂ C（GCF-G @ Mo ₂ C）异质结构被引入作为Li-S电池的独立电极，采用了一种简便而经济的方法。石墨烯片包裹的具有琼脂状多孔结构的碳掺杂泡沫可以促进快速的电子和离子传输，同时通过物理限制和化学吸附以及强极性-极性相互作用有效地固定多硫化物。更重要的是Mo ₂实验数据和第一性原理计算证明，C纳米颗粒可以充当化学锚定中心，以提供强大的多硫化物吸附能力。此外，Mo ₂ C的催化作用还加速了多硫化物转化的氧化还原动力学，从而有助于提高速率性能。结果，具有GCF-G @ Mo ₂ C的电池在600次循环后显示的初始容量高达862 mAh g ^-1，保留容量为597 mAh g ^-1，在1C速率下每个循环的容量衰减仅为0.051％ ，表现出良好的循环稳定性。此外，GCF-G @ Mo ₂ C衬底具有高硫含量（70重量％）和硫载量（10.5 mg cm ^-2））在0.1℃时可达到12.6 mAh cm ^-2的超高面积容量，为高性能Li-S电池提供了极具竞争力的正极。