Mitigating Polysulfide Shuttling via a Boron Carbon Nitride Microtube-Based Cathode for High-Performance Lithium–Sulfur Batteries

The commercialization of lithium–sulfur (Li–S) batteries faces challenges due to the insulating nature of sulfur and the pronounced lithium polysulfide shuttling within the electrolyte. To address these issues, we have synthesized and utilized boron carbon nitride (BCN) microtubes as a cathode host material. Recognized for their adaptable electrical properties and exceptional chemical and mechanical resilience, BCN materials are well-suited for Li–S battery applications. The polar characteristics and robust mechanical structure of the synthesized microtubules effectively immobilize soluble polysulfides, facilitating their conversion into lower-order insoluble polysulfides (Li2S and Li2S2) while maintaining electrical connectivity. Li–S cells fabricated using the BCN host material delivered a high initial discharge capacity of 1606 mAhg–1 at a rate of C/12. The cell exhibited stable Coulombic efficiency, nearly 100% over 350 cycles at a 2 C-rate. The incorporation of the BCN microtube network, featuring polar electrocatalytic sites, efficient pathways for ion and electron transport, and strong chemical affinity toward lithium polysulfides, makes it an efficient sulfur host for the advancement of high-performance Li–S batteries.