Iron oxide (Fe2 O3 ) is a promising anode material for next-generation high-energy lithium-ion batteries owing to its high theoretical specific capacity, but it suffers from unstable electrochemistry, as represented by a significant volume variation upon (de)lithiation and unstable solid-electrolyte interface. To target these issues, a double-coating synthetic route has been developed to prepare a yolk-shell-structured γ-Fe2 O3 /nitrogen-doped carbon composite, in which spindle-like γ-Fe2 O3 cores are encapsulated in the highly conductive carbon shell. Through precisely controlling the void space between the γ-Fe2 O3 core and the carbon shell, volume variation in γ-Fe2 O3 during (de)lithiation is well accommodated, while the composite maintains an intact and relatively dense structure, which stabilizes the solid-electrolyte interface and is beneficial for improving the practical energy density of the material. With a stabilized (de)lithiation electrochemistry and a synergistic storage effect between the two active components, the composite enables excellent lithium storage performance, in terms of reversible capacity, cycling ability, and rate capability.

中文翻译：

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在具有保留的空心空间的氮掺杂碳包覆的氧化铁卵黄壳纳米锭中的稳定锂存储。

氧化铁（Fe2 O3）由于具有较高的理论比容量，因此是用于下一代高能锂离子电池的有希望的负极材料，但是它遭受电化学不稳定的困扰，其表现为（去锂化和固体电解质界面不稳定。针对这些问题，已经开发了一种双涂层合成路线来制备蛋黄壳结构的γ-Fe2O3/氮掺杂碳复合材料，其中纺锤状的γ-Fe2O3核被包裹在高导电性碳中壳。通过精确控制γ-Fe2O3核与碳壳之间的空隙空间，可以很好地适应（去）锂化过程中γ-Fe2O3的体积变化，同时复合材料保持完整且相对致密的结构，它稳定了固体电解质界面，有利于提高材料的实际能量密度。凭借稳定的（脱锂）电化学和两个活性成分之间的协同存储作用，该复合材料在可逆容量，循环能力和倍率能力方面实现了出色的锂存储性能。