期刊
JOURNAL OF POWER SOURCES
卷 469, 期 -, 页码 -出版社
ELSEVIER
DOI: 10.1016/j.jpowsour.2020.228429
关键词
Marcasite-FeS2; Phase transition; Ether-based electrolyte; High cut-off voltage; Potassium-ion battery
资金
- National Key R&D Program of China [2018YFB0905600]
- Natural Science Foundation of Beijing [2192034]
- China Postdoctoral Science Foundation [2018M631335]
- Beijing Zhongkebaice Technology Service Co., Ltd.
Marcasite-FeS2 has significant potential as an anode material for potassium-ion batteries (KIBs) for its lower band gap, high theoretical capacity, low cost and environmental friendliness but suffers poor cycle stability and rate capability. Here, we design a marcasite-FeS2@carbon nanodots anchored on 3D cell-like S, N co-doped graphenic matrix (m-FeS2@C-SSNFG). The 3D graphenic matrix is constructed by graphenic cages and sustained by conductive graphitic struts that can curb the agglomeration of graphenic sheets during cycling. Remarkably, the yolk-shell m-FeS2@graphenic cage structure not only ensures uniform dispersion of m-FeS2 on the cell wall, but also offers enough void room to accommodate the volume expansion of m-FeS2. Meanwhile the graphitic carbon shell wrapped around m-FeS2 also prevents the active m-FeS2 nanodots from agglomeration and dissolving into electrolyte. It is worth underlining that the phase transition from semiconductor (m-FeS2) to conductor (KxFeS2) is firstly validated through first-principles calculations, beneficial to the electron transfer and K-ions diffusion in subsequent cycles. Besides, optimizing electrolyte and cut-off voltage can further boost its long-term cycle stability. Thus, it delivers high capacity of 419 mA h g(-1) after 100 cycles at 0.05 A g(-1) and ultralong cycle stability of 140 mA h g(-1) at 5 A g(-1) over 4000 cycles.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据