Mesoporous single-crystalline MnOx nanofibers@graphene for ultra-high rate and long-life lithium-ion battery anodes†
With the increasing energy demand of electronic devices and electric vehicles, the achievement of anode materials for lithium-ion batteries with high specific capacity and superior rate capability and cycling stability still remains a challenge. Herein, we report a novel strategy to prepare the core–shell mesoporous single-crystalline MnOx nanofibers@graphene (PSCMnOx@G) through a “spraying–rapid freezing” process. The elastic graphene shell not only improves the conductivity of the electrode but can also substantially inhibit the collapse of MnOx nanofibers (NFs) over continuous discharge–charge cycles. Moreover, the double-exchange interaction of manganese mixed-valence ions further improves the conductivity of manganese oxide, and Li ion diffusion is significantly enhanced by the vertically aligned single-crystalline and mesoporous structure of MnOx NFs. As a result, the PSCMnOx@G exhibits an ultrahigh rate performance (1072 mA h g−1 at 0.1 A g−1 and 419 mA h g−1 at 10 A g−1), which is among the best ever reported for MnOx based anodes, as well as excellent cycling stability (1162 mA h g−1 at 2 A g−1 over 500 cycles).
- This article is part of the themed collection: 2018 Journal of Materials Chemistry A HOT Papers