Optimization of Microporous Carbon Structures for Lithium–Sulfur Battery Applications in Carbonate‐Based Electrolyte

• Published in: Small (Weinheim an der Bergstrasse, Germany) Vol. 13; no. 11; pp. np - n/a
• Main Authors: Hu, Lei, Lu, Yue, Li, Xiaona, Liang, Jianwen, Huang, Tao, Zhu, Yongchun, Qian, Yitai
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 01.03.2017
• Subjects: Carbon; carbonate‐based electrolyte; Carbonization; Cathodes; Confining; Electrolytes; Lithium; Lithium sulfur batteries; microporous carbon; Nanotechnology; Optimization; Stability analysis; Sulfur; carbonate-based electrolyte; lithium-sulfur batteries; microporous carbon
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201603533

Developing appropriate sulfur cathode materials in carbonate‐based electrolyte is an important research subject for lithium‐sulfur batteries. Although several microporous carbon materials as host for sulfur reveal the effect, methods for producing microporous carbon are neither easy nor well controllable. Moreover, due to the complexity and limitation of microporous carbon in their fabrication process, there has been rare investigation of influence on electrochemical behavior in the carbonate‐based electrolyte for lithium‐sulfur batteries by tuning different micropore size(0–2 nm) of carbon host. Here, we demonstrate an immediate carbonization process, self‐activation strategy, which can produce microporous carbon for a sulfur host from alkali‐complexes. Besides, by changing different alkali‐ion in the previous complex, the obtained microporous carbon exhibits a major portion of ultramicropore (<0.7 nm, from 54.9% to 25.8%) and it is demonstrated that the micropore structure of the host material plays a vital role in confining sulfur molecule. When evaluated as cathode materials in a carbonate‐based electrolyte for Li‐S batteries, such microporous carbon/sulfur composite can provide high reversible capacity, cycling stability and good rate capability. Microporous carbon with a 3D structure is prepared by the immediate carbonization of alkali complexes. It is vital to develop a simple and efficient approach to tailor precisely microporous structure of carbon host for better accommodation of sulfur in carbonate‐based electrolyte.