Ultrasmall y-Fe203 nanodots （- 3.4 nm） were homogeneously encapsulated in interlinked porous N-doped carbon nanofibers （labeled as Fe2O3@C） at a considerable loading （-51 wt.%） via an electrospinning technique. ...Ultrasmall y-Fe203 nanodots （- 3.4 nm） were homogeneously encapsulated in interlinked porous N-doped carbon nanofibers （labeled as Fe2O3@C） at a considerable loading （-51 wt.%） via an electrospinning technique. Moreover, the size and content of Fe2O3 could be controlled by adjusting the synthesis conditions. The obtained Fe203@C that functioned as a self-standing membrane was used directly as a binder- and current collector-free anode for sodium-ion batteries, displaying fascinating electrochemical performance in terms of the exceptional rate capability （529 mA.h.gq at 100 mA-g-1 compared with 215 mA-h-g-1 at 10,000 mA.g-1） and unprecedented cyclic stability （98.3% capacity retention over 1,000 cycles）. Furthermore, the Na-ion full cell constructed with the Fe2O3C anode and a P2-Na2/3Ni1/3Mn2/302 cathode also exhibited notable durability with 97.2% capacity retention after 300 cycles. This outstanding performance is attributed to the distinctive three-dimensional network structure of the very-fine Fe203 nanoparticles uniformly embedded in the interconnected porous N-doped carbon nanofibers that effectively facilitated electronic/ionic transport and prevented active materials pulverization/aggregation caused by volume change upon prolonged cycling. The simple and scalable preparation route, as well as the excellent electrochemical performance, endows the Fe2O3@C nanofibers with great prospects as high-rate and long-life Na-storage anode materials.展开更多
文摘Ultrasmall y-Fe203 nanodots （- 3.4 nm） were homogeneously encapsulated in interlinked porous N-doped carbon nanofibers （labeled as Fe2O3@C） at a considerable loading （-51 wt.%） via an electrospinning technique. Moreover, the size and content of Fe2O3 could be controlled by adjusting the synthesis conditions. The obtained Fe203@C that functioned as a self-standing membrane was used directly as a binder- and current collector-free anode for sodium-ion batteries, displaying fascinating electrochemical performance in terms of the exceptional rate capability （529 mA.h.gq at 100 mA-g-1 compared with 215 mA-h-g-1 at 10,000 mA.g-1） and unprecedented cyclic stability （98.3% capacity retention over 1,000 cycles）. Furthermore, the Na-ion full cell constructed with the Fe2O3C anode and a P2-Na2/3Ni1/3Mn2/302 cathode also exhibited notable durability with 97.2% capacity retention after 300 cycles. This outstanding performance is attributed to the distinctive three-dimensional network structure of the very-fine Fe203 nanoparticles uniformly embedded in the interconnected porous N-doped carbon nanofibers that effectively facilitated electronic/ionic transport and prevented active materials pulverization/aggregation caused by volume change upon prolonged cycling. The simple and scalable preparation route, as well as the excellent electrochemical performance, endows the Fe2O3@C nanofibers with great prospects as high-rate and long-life Na-storage anode materials.
