The dissolution and diffusion of polysulfide compounds in lithium-sulfur (Li-S) batteries restrict their cyclic stability. The sulfur hosts are the key to achieve good cyclic stability for Li-S batteries. Here, a three-dimensional hierarchical heteroatoms B, N-doped porous carbon (BNC) was prepared as a new sulfur host. The active sulfur can be anchored inside the cathode due to the incorporation of atomic functional groups formed by B and N co-doping, which enhances the adsorption capacity between the cathode and lithium polysulfides. The resulting BNC loaded sulfur (S@BNC) cathode exhibits high specific capacity and electrochemical stability. Specifically, the reversible specific capacity of S@BNC cathode achieved a reversible specific capacity of 1056.8 mAh g−1 at 0.1 C. After 500 cycles, the specific capacity still remains 618.5 mAh g−1 at 0.2 C, which corresponds to a capacity decay rate of 0.0776 %. The results suggest that BNC has great potential as the sulfur host for achieving high performance of Li-S batteries.

中文翻译：

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B、N共掺杂3D分级多孔碳包埋硫以实现高性能锂硫电池


锂硫（Li-S）电池中多硫化物的溶解和扩散限制了其循环稳定性。硫主体是锂硫电池实现良好循环稳定性的关键。在此，制备了三维分级杂原子 B、N 掺杂的多孔碳（BNC）作为新的硫主体。由于B和N共掺杂形成的原子官能团的引入，活性硫可以锚定在正极内部，从而增强了正极与多硫化锂之间的吸附能力。由此产生的 BNC 负载硫 (S@BNC) 阴极表现出高比容量和电化学稳定性。具体来说，S@BNC正极的可逆比容量在0.1 C下达到了1056.8 mAh g−1的可逆比容量。经过500次循环后，0.2 C下的比容量仍然保持在618.5 mAh g−1，这对应于容量衰减率为 0.0776%。结果表明，BNC 作为硫主体具有实现锂硫电池高性能的巨大潜力。