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Indexed by:Journal Papers

Date of Publication:2019-06-14

Journal:CHEMELECTROCHEM

Included Journals:SCIE、EI

Volume:6

Issue:12

Page Number:3043-3048

ISSN No.:2196-0216

Key Words:sodium-ion batteries; anodes; high rate capacity; carbon nanosheets; NaNH2 treatment

Abstract:Sodium-ion batteries are regarded as a promising alternative for scalable electricity storage, but the rate capability is still a scientific challenge to be solved, owing to the poor Na+ kinetics in electrodes. Herein, nitrogen-doped carbon nanosheets with rich defects, nanopores and various interlayer spacings are prepared by pre-carbonized polymer sheets at different temperatures followed by sodium amide treatment. Combination of thin nanosheets, nanopores and large interlayer spacing can boost the rapid Na+ diffusion, as proven by the calculation of the diffusion coefficient. Meanwhile, the kinetics analysis demonstrates the capacitive behaviors, which favor fast Na+ storage. When applied as an anode, the material exhibits superior rate capability (111.1 mA h g(-1) even at 20 A g(-1)), remarkable cycle stability (over 2000 cycles) and ultrahigh initial coulombic efficiency (81.4 %). Furthermore, this work demonstrates a new way to develop attractive high-rate carbon anode materials for sodium-ion batteries.