Microscopic observation of nanoporous Si-Li3PS4 interface in composite anodes with stable cyclability
Microscopic observation of nanoporous Si-Li3PS4 interface in composite anodes with stable cyclability
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DOI：
10.1016/j.elecom.2021.107100
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发表时间：
2021-07-31
影响因子：
5.4
通讯作者：
Takahashi, Masanari
中科院分区：
文献类型：
--
作者：
Okuno, Ryota;Yamamoto, Mari;Takahashi, Masanari
采用Mg_2Si还原SiO_2烟气制备纳米多孔Si颗粒，并将其与Li_3PS_4固体电解质复合，以适应Si的体积膨胀。充电/放电后的横截面FE-SEM和EDX测量表明，纳米多孔Si颗粒/聚集体缠结周围的电解质，使紧密接触，从而保持低的界面电阻和高的循环稳定性。然而，在非多孔Si复合阳极中，在Si-Li 3 PS4界面处形成大的裂纹，导致低容量保持率。据我们所知，这是第一个微观研究表明，纳米多孔结构减轻了硅的体积变化。
Nanoporous Si particles, which are prepared from Mg2Si reduction of SiO2 fumes, and Li3PS4 solid electrolyte are composited to accommodate the volume expansion of Si. Cross-sectional FE-SEM and EDX measurements after charging/discharging show that nanoporous Si particles/aggregates entangle the surrounding electrolyte to make close contact, resulting in the preservation of low interfacial resistance and high cycle stability. While, in non-porous Si composite anodes, large cracks are formed at the Si-Li3PS4 interface, causing low capacity retention. To the best of our knowledge, this is the first microscopic study to demonstrate that nanoporous structure relieves the volume change of Si.