The volume of the metallic lithium anode in all-solid-state Li metal batteries increases significantly due to the lithium dendrite formation during the battery cycling, and the rough surface of lithium metal also reduces Li-ion transport in Li/electrolyte interface. In this work, we developed a solid polymer composite by adding the low-cost Si3N4 particles to protect the lithium anode in all-solid-state batteries. The Fourier transform infrared spectroscopy (FTIR) data show that the surface of 10 wt % Si3N4 particles interacts with the polyethylene oxide (PEO) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) salt; the interaction restricts the anion mobility and improves the ionic conductivity (1 × 10−4 S·cm−1) and lithium-ion transference number (0.28) of the composite electrolyte. The lithium metal anode is well protected by the composite electrolyte in all-solid-state cells, including symmetric and Li/LiFePO4 cells. The lithium dendrite growth suppression by this composite electrolyte indicates the possible application of these low-cost composite electrolytes for lithium metal protection.

中文翻译：

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用复合电解质保护全固态电池中的锂金属负极

由于电池循环过程中锂枝晶的形成，全固态锂金属电池中金属锂负极的体积显着增加，并且锂金属的粗糙表面也降低了锂/电解质界面中锂离子的传输。在这项工作中，我们通过添加低成本的 Si3N4 颗粒开发了一种固体聚合物复合材料，以保护全固态电池中的锂负极。傅里叶变换红外光谱 (FTIR) 数据表明，10 wt% Si3N4 颗粒的表面与聚环氧乙烷 (PEO) 和双（三氟甲磺酰基）亚胺锂 (LiTFSI) 盐相互作用；这种相互作用限制了阴离子的迁移率，提高了复合电解质的离子电导率（1×10-4 S·cm-1）和锂离子迁移数（0.28）。在全固态电池（包括对称和 Li/LiFePO4 电池）中，锂金属负极受到复合电解质的良好保护。这种复合电解质对锂枝晶生长的抑制表明这些低成本复合电解质可能用于锂金属保护。