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Indexed by:Journal Papers

Date of Publication:2019-06-07

Journal:CHEMSUSCHEM

Included Journals:SCIE、EI、PubMed

Volume:12

Issue:11

Page Number:2447-2456

ISSN No.:1864-5631

Key Words:bifunctional separator; freestanding cathode; lithium-sulfur battery; polysulfide trapping; beta-MnO2 nanowire

Abstract: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 beta-MnO2 nanowire/graphene-modified separator is used to improve the performance of CNF cloth/S cathodes without changing their structure. beta-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.