In Situ Formed Lithium Sulfide/Microporous Carbon Cathodes for Lithium-Ion Batteries

• Published in: ACS nano Vol. 7; no. 12; pp. 10995 - 11003
• Main Authors: Zheng, Shiyou, Chen, Yvonne, Xu, Yunhua, Yi, Feng, Zhu, Yujie, Liu, Yihang, Yang, Junhe, Wang, Chunsheng
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 23.12.2013
• Subjects: Carbon; Cathodes; Electrolytic cells; Lithium; Lithium-ion batteries; Particulate composites; Strategy; Sulfides; Sulfur; Li2S; microporous carbon; Li-ion battery; lithium−sulfur
• ISSN: 1936-0851; 1936-086X
• DOI: 10.1021/nn404601h

Highly stable sulfur/microporous carbon (S/MC) composites are prepared by vacuum infusion of sulfur vapor into microporous carbon at 600 °C, and lithium sulfide/microporous carbon (Li2S/MC) cathodes are fabricated via a novel and facile in situ lithiation strategy, i.e., spraying commercial stabilized lithium metal powder (SLMP) onto a prepared S/MC film cathode prior to the routine compressing process in cell assembly. The in situ formed Li2S/MC film cathode shows high Coulombic efficiency and long cycling stability in a conventional commercial Li-ion battery electrolyte (1.0 M LiPF6 + EC/DEC (1:1 v/v)). The reversible capacities of Li2S/MC cathodes remain about 650 mAh/g even after 900 charge/discharge cycles, and the Coulombic efficiency is close to 100% at a current density of 0.1C, which demonstrates the best electrochemical performance of Li2S/MC cathodes reported to date. Furthermore, this Li2S/MC film cathode fabricated via our in situ lithiation strategy can be coupled with a Li-free anode, such as graphite, carbon/tin alloys, or Si nanowires to form a rechargeable Li-ion cell. As the Li2S/MC cathode is paired with a commercial graphite anode, the full cell of Li2S/MC-graphite (Li2S-G) shows a stable capacity of around 600 mAh/g in 150 cycles. The Li2S/MC cathodes prepared by high-temperate sulfur infusion and SLMP prelithiation before cell assembly are ready to fit into current Li-ion batteries manufacturing processes and will pave the way to commercialize low-cost Li2S-G Li-ion batteries.