Hypercrosslinked Polymerization Enabled N‐Doped Carbon Confined Fe2O3 Facilitating Li Polysulfides Interface Conversion for Li–S Batteries

다국어 초록 (Multilingual Abstract)

Facilitating phase conversion efficiency of Li polysulfides to Li2S and restraining the dissolution of Li polysulfides are critical for stable lithium–sulfur (Li–S) batteries. Herein, an in situ formed sulfiphilic superfine Fe2O3 nanocrystals confined in lithiophilic N‐doped microporous carbon (Fe2O3/N‐MC) is derived from one‐step hypercrosslinked polymerization. Uniquely, the dual active sites (Fe2O3 and N) in Fe2O3/N‐MC tend to form “FeS, LiO or LiN” bonding, and then synchronically enhancing the chemisorption and interface conversion ability of Li polysulfides. As a result, 80 wt% S is loaded on Fe2O3/N‐MC and the hybrid cathode delivers high mass capacity (730 mA h g‐1) and excellent cycling stability (87.1% capacity retention over 1000 cycles at 5.0 C). Especially, the cathode also exhibits a high reversible areal capacity of 3.69 mA h cm‐2 at a high areal loading (5.1 mg cm‐2) and a lean electrolyte/sulfur (E/S) ratio (7.5 µL mg‐1) over 500 cycles. This work is anticipated to deepen the comprehension of complex Li polysulfides interphase conversion processes and afford new thoughts for designing new host materials.
Facilitating phase conversion efficiency of Li polysulfides to Li2S and restraining the dissolution of Li polysulfides are critical for stable lithium–sulfur (Li–S) batteries. The as‐prepared Fe2O3/N‐microporous carbon (MC) is in favor of enhancing sulfur content, releasing volume expansion, immobilizing soluble lithium polysulfides (LiPSs), and optimizing Li2S nucleation, hence accommodating the S@Fe2O3/N‐MC cathode with excellent cycling stability.