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论文类型：期刊论文

发表时间：2019-06-14

发表刊物：CHEMELECTROCHEM

收录刊物：SCIE、EI

卷号：6

期号：12

页面范围：3043-3048

ISSN号：2196-0216

关键字：sodium-ion batteries; anodes; high rate capacity; carbon nanosheets; NaNH2 treatment

摘要：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.