Abstract：
The garnet-type electrolyte Li6.4La3Zr1.4Ta0.6O12 (LLZTO) has been widely researched for its high ionic conductivity and excellent stability against the Li anode. However, the garnet electrolyte is susceptible to CO2 and H2O in air to form a Li2CO3 insulating layer leading to poor wettability with the Li anode, which hinders its practical application. Herein, we introduced a simple method to effectively reduce the Li2CO3 layer on the garnet electrolyte surface by laser cleaning and made the garnet surface back with lithiophilicity. The resulting Li/garnet interfacial resistance decreased to 76.4 Ω·cm2 at 30 °C and 3.1 Ω·cm2 at 80 °C. The assembled Li symmetric cell with the as-laser-treated electrolyte steadily cycled for 300 h under 0.1 and 0.2 mA·cm-2 at 80 °C. The solid-state battery coupled with the composite LiFePO4 cathode and the Li anode exhibited stable long-term cycling performance for over 100 cycles with a capacity retention of 84.8%. This work provided a novel method to reduce the surface inert layer and make the garnet electrolyte reveal the intrinsic lithiophilicity by laser cleaning process with high efficiency, which helped address the challenges for the application of garnet-based solid-state batteries.
摘要：
石榴石型电解质Li6.4La3Zr1.4Ta0.6O12（LLZTO）以其高离子电导率和对Li阳极的优异稳定性而被广泛研究。然而,石榴石电解质对空气中的CO2和H2O敏感，形成Li2CO3绝缘层，导致与Li阳极的润湿性差，这阻碍了它的实际应用。在这里，我们介绍了一种简单的方法，通过激光清洗有效地减少石榴石电解质表面的Li2CO3层，使石榴石表面具有亲锂性。所得的Li/石榴石界面电阻在30°C时降低到76.4Ω·cm2，在80°C时降低到3.1Ω·cm2。组装的Li对称电池与激光处理的电解质在0.1和0.2mA·cm-2下在80°C下稳定循环300小时。与复合LiFePO4阴极和Li阳极耦合的固态电池在超过100次循环中表现出稳定的长期循环性能，容量保持率为84.8％。这项工作提供了一种新颖的方法，以减少表面惰性层，并通过高效的激光清洗工艺使石榴石电解质显示固有的亲锂性，这有助于解决基于石榴石的固态电池应用的挑战。
