N-doped carbon-coated hollow carbon nanofibers with interspersed TiO2 for integrated separator of Li-S batteries. (20th February 2019)

• Record Type: Journal Article
• Authors: Yang, Yuebin; Xu, Hui; Wang, Shanxing; Deng, Yuanfu; Qin, Xianying; Qin, Xusong; Chen, Guohua
• Is Part Of: Electrochimica acta. Volume 297(2019)
• Page Start: 641
• Page End: 649
• Publication Date: 2019-02-20
• Subjects: Li-S batteries -- Separator -- Carbon nanofibers -- TiO2 -- Interlayer; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2018.12.009
• Languages: English
• ISSNs: 0013-4686

Abstract

Abstract: Li-ion batteries have held a dominant position in the energy storage area for decades. However, due to the limitation of its chemistry, the energy density of Li-ion batteries is limited to ∼300 W h kg −1 . In recent years, more attention has been paid to the Li-S batteries that are environmentally friendly, cost-effective and high energy density (theoretical value of cathode: ∼2600 W h kg −1 ). In this study, carbonized polydopamine (C-PDA)-coated hollow carbon nanofibers (CNFs) with TiO2 nanoparticles interspersed in the void space between the CNF skeleton and carbon coating layer were subtly designed. The C-PDA/TiO2 /CNF composite (CTC) was integrated with the commercial separator as a polysulfide filter to achieve high-performance Li-S batteries. It is reveals that the CTC coating layer could effectively filter and reactivate the dissolved polysulfides to achieve a stabilized sulfur-based cathode. The Li-S battery assembled by this integrated separator and the regular cathode (sulfur/Ketjen black) with 72.7 wt% of sulfur achieved a high specific capacity and low decay rate (632.5 mAh g −1 at the first cycle and 0.06% per cycle) at 2.0C for 500 cycles. These good results indicate that the C-PDA/TiO2 /CNF-modified separator could be a promising separator candidate for high performance Li-S batteries.