The garnet type solid-state electrolyte (SSE) encounters challenges related to poor interfacial contact with Li metal and dendrite penetration problem. This study addresses these issues by manipulating the surface property of garnet-based LLZTO (LiLaZrTaO) SSE. The manipulation is achieved by varying thickness of AlO atomic layer deposition (ALD), followed by sintering. Research results show that the relative density, ionic conductivity, and hardness of LLZTO are improved while electronic conductivity is reduced due to the formation of multiple complexions at grain boundary (GB). The SSE pellets also demonstrate improved wettability with Li metal, leading to stable galvanostatic Li plating/stripping cycling with low polarization, which allows for batter battery performance than pristine one. The concept of modifying SSE through the grain boundary complexion modification by thin ALD coating for enhancing the dendrite tolerance with better electrochemical properties of SSE may open a new direction for solid state battery research.

中文翻译：

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石榴石基固态锂电池界面稳定性的晶界改性

石榴石型固态电解质（SSE）面临与锂金属界面接触不良和枝晶渗透问题相关的挑战。本研究通过控制石榴石基 LLZTO (LiLaZrTaO) SSE 的表面特性来解决这些问题。这种操控是通过改变 Al2O3 原子层沉积 (ALD) 的厚度，然后进行烧结来实现的。研究结果表明，由于晶界（GB）处形成多重络合物，LLZTO的相对密度、离子电导率和硬度得到提高，而电子电导率降低。 SSE 颗粒还表现出与锂金属的润湿性得到改善，从而实现稳定的恒电流镀锂/剥离循环和低极化，从而使电池性能比原始电池更佳。通过薄 ALD 涂层对晶界络合物进行改性来改性 SSE 的概念，以提高 SSE 的枝晶耐受性和更好的电化学性能，可能为固态电池研究开辟新方向。