Hierarchical sparse Co nanowire/carbon nanofiber arrays as 3D Li+ gateways for high rate, long-life lithium-sulfur batteries

Abstract

Lithium‑sulfur batteries (LSBs) have been investigated as promising electrochemical energy storage owing to their high theoretical energy density. However, practical applications of LSBs are still hindered by rapid capacity decay and short cycle life, especially at high rates. Here, highly hierarchical sparse Co-nanowire/carbon nanofiber/sulfur arrays (CoNws/CNFs/S) were fabricated inside porous alumina template using a combination of electrodeposition, polymer pyrolysis, and infiltration methods. As a consequence, the sulfur host structure made with CoNWs/CNFs can deliver high rate capability and cycle stability with a high capacity of 1010 mAh g-1 and a low capacity fading rate of 0.3% per cycle (after 200 cycles under a rate of 1C). Our result suggests that designing hybrid coaxial architecture could represent an attractive path to improve high power density LSBs.