A CNT-sheathed 3D-ordered N-doped carbon framework enabling efficient charge transport and polysulfide regulation for durable Li–S batteries

초록

Electrode architectures that couple polysulfide conversion, ion transport, electron conduction, and structural stability are needed for high-rate, long-life Li–S batteries. Here, an ordered N-doped carbon framework (ONCF) derived from opal-templated ZIF-67 is developed as a sulfur host. ONCF contains a 3D-ordered macroporous carbon skeleton conformally decorated with in situ grown N-doped CNTs, integrating ordered macropores, CNT-associated mesospaces, intrinsic microporosity, and electronically connected N/Co-containing surfaces. In 0.25 M Li2S8 symmetric cells, ONCF shows stronger polysulfide redox responses and lower interfacial resistance than bulk-derived NCF, indicating improved sulfur-redox kinetics. In Li–S coin cells, S@ONCF delivers 1269.7 mAh g−1 initially and 1021.1 mAh g−1 after 200 cycles at 0.2 A g−1, maintains 931.8 mAh g−1 at 3 A g−1, and retains 746.9 mAh g−1 after 750 cycles at 2 A g−1. Post-cycling SEM and XPS indicate preserved porosity and a LiF-containing cathode–electrolyte interphase. A preliminary pouch-format Li–S cell with ∼4.0 mg cm−2 sulfur loading delivers 545.4 mAh g−1 after 300 cycles, supporting the use of CNT-sheathed ordered carbon hosts for durable Li–S batteries. © 2026 Elsevier B.V. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

키워드