A facile approach is developed to fabricate polypyrrole-encapsulated lamellar iron (II) selenide (FeSe/PPy) by directly exposing FeSe to pyrrole atmosphere at room temperature. A high FeSe loading of 97 wt.% is achieved for the FeSe/PPy composite, which is designed as an anode for lithium-ion battery (LIB) with much enhanced electrochemical performance than that of the FeSe sample. The FeSe/PPy electrodes demonstrate a reversible discharge capacity of 274 mAh g[Formula: see text] after 50 cycles at a high current density of 0.5 A g[Formula: see text], whereas the lower discharge capacity of 124 mAh g[Formula: see text] for the FeSe electrodes. The FeSe/PPy electrodes also deliver greater rate capability compared to the FeSe electrodes. The improved electrochemical performance should be assigned to the contributions of fast charge transfer and structural defense from the encapsulated PPy. Hence, the FeSe/PPy composite could serve the purpose for constructing reliable anode for LIB, and the simple method of PPy coating can also be used to build high-performance electrodes for other battery systems.

中文翻译：

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片状铁 (II) 硒化物的薄聚吡咯封装的简便方法，大大提高了锂离子存储的性能

通过在室温下将 FeSe 直接暴露于吡咯气氛中，开发了一种简便的方法来制造聚吡咯封装的层状铁 (II) 硒化物 (FeSe/PPy)。FeSe/PPy 复合材料实现了 97 wt.% 的高 FeSe 负载，该复合材料被设计为锂离子电池 (LIB) 的阳极，其电化学性能比 FeSe 样品的电化学性能要好得多。FeSe/PPy 电极在 0.5 A g 的高电流密度下循环 50 次后的可逆放电容量为 274 mAh g[公式：见文本][公式：见文本]，而较低的放电容量为 124 mAh g[公式: 见正文] 对于 FeSe 电极。与 FeSe 电极相比，FeSe/PPy 电极还提供更大的倍率能力。改进的电化学性能应该归因于封装的 PPy 的快速电荷转移和结构防御。因此，FeSe/PPy复合材料可用于构建可靠的LIB负极，PPy涂层的简单方法也可用于构建其他电池系统的高性能电极。