A Novel TiO2-Wrapped Activated Carbon Fiber/Sulfur Hybrid Cathode for High Performance Lithium Sulfur Batteries. (20th August 2016)

• Record Type: Journal Article
• Authors: Xie, Keyu; Zhang, Kun; Han, Yunzhao; Yuan, Kai; Song, Qiang; Wang, Jian-gan; Shen, Chao; Liu, Xingrui; Wei, Bingqing
• Is Part Of: Electrochimica acta. Volume 210(2016)
• Page Start: 415
• Page End: 421
• Publication Date: 2016-08-20
• Subjects: ：activated carbon fiber cloth -- titanium dioxide -- cathode materials -- lithium-sulfur batteries -- energy storage; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2016.05.172
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: A well-designed TiO2 -wrapped ACF/S hybrid cathode is proposed. The hybrid cathode exhibits good rate and cycling performance. Each part of the hybrid cathode plays its desired role. Abstract: Traditional Li-ion batteries are encountering a technical hurdle in further increasing their energy density. Li-S batteries have been attracted increasing attention owing to the high theoretical capacity of element sulfur (S, 1672 mAh g −1 ). Nevertheless, the insulation nature of the S element and polysulfide shuttle effect, resulting in low S utilization and poor cycling stability, are the main obstacles to widespread practical utilization of Li-S batteries. To tackle these issues, a well-designed hybrid cathode, consisted of S-infused activated carbon fiber (ACF) cloth and a thin TiO2 wrapping layer (TiO2 -ACF/S), is developed in this work with the TiO2 wrapping layer as a polysulfide chemisorption layer, while the ACF cloth being a conductive network. Compared to the pure S and ACF/S cathodes, the TiO2 -ACF/S hybrid cathode, with a high S loading of about 3.0 mg cm −2, displays an improved initial specific capacity (915 mAh g −1 at 0.2C), cycle stability (capacity retention of 77% after 100 cycles, 702 mAh g −1 ), and rate ability (438 mAh g −1 at 5C). The enhanced electrochemical performances of TiO2 -ACF/S hybrid cathode are attributed to the synergistic effects from TiO2 (polysulfide chemisorption material), ACF (electronically conductive material) and S (high hosting capacity of Li ions).