祝贺王舜和金辉乐老师在advanced energy materials发表学术论文-威尼斯人888

标题：a novel graphene oxide wrapped na2fe2(so4)3/c cathode composite for long life and high energy density sodium-ion batteries

abstract: the cathode materials in the na-ion battery system are always the key issue obstructing wider application because of their relatively low specifc capacity and low energy density. a graphene oxide (go) wrapped composite, na2fe2(so4)3@c@go, is fabricated via a simple freeze-drying method. the as-prepared material can deliver a 3.8 v platform with discharge capacity of 107.9 mah g-1 at 0.1 c (1 c = 120 ma g-1) as well as offering capacity retention above 90% at a discharge rate of 0.2 c after 300 cycles. the well-constructed carbon network provides fast electron transfer rates, and thus, higher power density also can be achieved (75.1 mah g-1 at 10 c). the interface contribution of go and na2fe2(so4)3 is recognized and studied via density function theory calculation. the na storage mechanism is also investigated through in situ synchrotron x-ray diffraction, and pseudocapacitance contributions are also demonstrated. the diffusion coeffcient of naions is around 10-12–10-10.8 cm2 s-1 during cycling. the higher working voltage of this composite is mainly ascribed to the larger electronegativity of the element s. the research indicates that this well-constructed composite would be a competitive candidate as a cathode material for na-ion batteries.

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