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论文类型：期刊论文

发表时间：2019-03-22

发表刊物：ChemSusChem

收录刊物：PubMed

ISSN号：1864-564X

关键字：bifunctional separator,freestanding cathode,lithium-sulfur battery,polysulfide trapping,β-MnO2 nanowire

摘要：The development of carbon nanofiber (CNF) cloth-based cathodes is essential for the fabrication of high energy density and flexible Li-S batteries. Surface modification is generally used to improve the electrochemical performance of CNF cloth/S cathodes. However, this strategy creates some problems such as structure collapse, complex fabrication steps, and poor consistency. Herein, a β-MnO2 nanowire/graphene-modified separator is used to improve the performance of CNF cloth/S cathodes without changing their structure. β-MnO2 can facilitate chemical bonding with polysulfides, whereas graphene can decrease the inner resistance and trap polysulfide by physical shielding. The cathode with the bifunctional separator displayed a high discharge capacity of 529.9 mAh g-1 with a low capacity decay of 0.051 % per cycle after 500 cycles at 1 C, which is 3 times higher compared with a bare separator. Even with a high sulfur loading of 9.0 mg cm-2 , a high areal capacity of 3.8 mAh cm-2 was delivered over 100 cycles.© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.