Solid-state electrolytes in rechargeable all-solid-state Li-metal batteries, which have better safety and higher specific capacity than conventional rechargeable Li-ion batteries with liquid electrolytes, are limited by the low Li-ion conductivity of the solid electrolyte and the large electrolyte/electrode interfacial resistance. Here, we report a new rhombohedral NASICON structure Li1.4Sr0.2Hf1.8(PO4)3 with a high Li-ion conductivity of 1.62 × 10−5 S·cm−1 at 25 °C, and its conductivity can be improved to 3.4 × 10−5 S·cm−1 after the densification of the pellet by hot pressing. Li1.4Sr0.2Hf1.8(PO4)3 coated by a thin layer of polymer electrolyte showed a stable low-impedance dendrite-free plating/stripping process in a symmetric Li/Li cell for 100 h; moreover, the Li1.4Sr0.2Hf1.8(PO4)3 electrolyte had a small interfacial resistance in all-solid-state Li/LiFePO4 cell, which allows a high Coulombic efficiency and good cycling of the cell.

中文翻译：

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用于全固态锂金属电池的 Sr2+ 掺杂菱形 LiHf2(PO4)3 固体电解质

可充电全固态锂金属电池中的固态电解质比具有液体电解质的传统可充电锂离子电池具有更好的安全性和更高的比容量，但受限于固态电解质的低锂离子电导率和电解质/电极界面电阻大。在这里，我们报告了一种新的菱形 NASICON 结构 Li1.4Sr0.2Hf1.8(PO4)3，在 25 °C 时具有 1.62 × 10−5 S·cm−1 的高锂离子电导率，并且其电导率可以提高到3.4 × 10-5 S·cm-1 球团通过热压致密化。由聚合物电解质薄层涂覆的 Li1.4Sr0.2Hf1.8(PO4)3 在对称 Li/Li 电池中表现出稳定的低阻抗无枝晶电镀/剥离过程 100 小时；此外，Li1.4Sr0.2Hf1.