Solid‐state polymer electrolytes provide better flexibility and electrode contact than their ceramic counterparts, making them a worthwhile pursuit for all‐solid‐state lithium‐metal batteries. However, their large Li/solid state electrolyte interfacial resistance, small critical current density, and rapid lithium dendrite growth during cycling still limit their viability. Owing to these restrictions, all‐solid‐state cells with solid polymer electrolytes must be cycled above room‐temperature and with a small current density. These problems can be mitigated with an in situ formed artificial solid electrolyte interphase that rapidly conducts Li⁺ ions. Herein, a Li₃P layer formed in situ at the Li‐metal/solid polymer electrolyte interphase is reported that significantly reduces the electrode/electrolyte interfacial resistance. Additionally, this layer increases the wettability of the solid polymer by the metallic lithium anode, allowing for the critical current density of lithium symmetric cells to be doubled by homogenizing the current density at the interface. All‐solid‐state Li/Li symmetric cells and Li/LiFePO₄ cells with the Li₃P layer show improved cycling performance with a high current density.

中文翻译：

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Li3P层的原位形成可实现跨Li /固体聚合物电解质界面的快速Li +导电

固态聚合物电解质比陶瓷电解质具有更好的柔韧性和电极接触性，使它们成为全固态锂金属电池的值得追求的目标。然而，它们较大的锂/固态电解质界面电阻，较小的临界电流密度以及循环过程中快速的锂枝晶生长仍然限制了它们的生存能力。由于这些限制，所有带有固体聚合物电解质的固态电池必须在室温以上且电流密度较小的情况下循环。这些问题可以通过快速传导Li ⁺离子的原位形成的人造固体电解质中间相来缓解。在这里，李₃据报道，在锂金属/固体聚合物电解质界面形成的P层可显着降低电极/电解质的界面电阻。另外，该层增加了金属锂阳极对固体聚合物的润湿性，从而通过使界面处的电流密度均匀化，使锂对称电池的临界电流密度增加了一倍。具有Li ₃ P层的全固态Li / Li对称电池和Li / LiFePO ₄电池在高电流密度下显示出改善的循环性能。