Charging current densities of solid-state batteries with lithium metal anodes and ceramic electrolytes are severely limited due to lithium dendrites that penetrate the electrolyte leading to a short circuit. We show that dendrite growth can be inhibited by different crack deflection mechanisms when multi-layered solid electrolytes, such as Li6PS5Cl/Li3ScCl6/Li6PS5Cl and Li6PS5Cl/Li10GeP2S12/Li6PS5Cl, are employed but not when the inner layer is Li3PS4. X-ray tomographic imaging shows crack deflection along mechanically weak interfaces between solid electrolytes as a result of local mismatches in elastic moduli. Cracks are also deflected laterally within Li3ScCl6, which contains preferentially oriented particles. Deflection occurs without lithium being present. In cases where the inner layers react with lithium, the resulting decomposition products can fill and block crack propagation. All three mechanisms are effective at low stack pressures. Operating at 2.5 MPa, multi-layered solid electrolytes Li6PS5Cl/Li3ScCl6/Li6PS5Cl and Li6PS5Cl/Li10GeP2S12/Li6PS5Cl can achieve lithium plating at current densities exceeding 15 mA cm−2.

中文翻译：

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偏转多层固体电解质中的锂枝晶裂纹


由于锂枝晶穿透电解质导致短路，具有锂金属阳极和陶瓷电解质的固态电池的充电电流密度受到严重限制。我们发现，当采用多层固体电解质（例如 Li6PS5Cl/Li3ScCl6/Li6PS5Cl 和 Li6PS5Cl/Li10GeP2S12/Li6PS5Cl）时，不同的裂纹偏转机制可以抑制枝晶生长，但当内层为 Li3PS4 时则不会。 X 射线断层扫描成像显示，由于弹性模量的局部不匹配，固体电解质之间的机械弱界面上出现裂纹偏转。 Li3ScCl6 中含有优先取向的颗粒，裂纹也会横向偏转。在没有锂存在的情况下会发生偏转。如果内层与锂发生反应，产生的分解产物可以填充并阻止裂纹扩展。所有三种机制在低烟囱压力下均有效。在2.5 MPa下工作，多层固体电解质Li6PS5Cl/Li3ScCl6/Li6PS5Cl和Li6PS5Cl/Li10GeP2S12/Li6PS5Cl可以在超过15 mA cm−2的电流密度下实现锂电镀。