Department of Mechanical and Materials Engineering, University of Western Ontario , London, Ontario N6A 5B9, Canada.
Department of Chemistry, University of Western Ontario , London, Ontario N6A 5B7, Canada.
ACS Appl Mater Interfaces. 2017 Sep 20;9(37):31786-31793. doi: 10.1021/acsami.7b07113. Epub 2017 Sep 11.
Development of solid-state electrolyte (SSE) thin films is a key toward the fabrication of all-solid-state batteries (ASSBs). However, it is challenging for conventional deposition techniques to deposit uniform and conformal SSE thin films in a well-controlled fashion. In this study, atomic layer deposition (ALD) was used to fabricate lithium silicate thin films as a potential SSE for ASSBs. Lithium silicates thin films were deposited by combining ALD LiO and SiO subcycles using lithium tert-butoxide, tetraethylorthosilane, and HO as precursors. Uniform and self-limiting growth was achieved at temperatures between 225 and 300 °C. X-ray absorption spectroscopy analysis disclosed that the as-deposited lithium silicates were composed of SiO tetrahedron structure and lithium oxide as the network modifier. X-ray photoelectron spectroscopy confirmed the chemical states of Li in the thin films were the same with that in standard lithium silicate. With one to one subcycle of LiO and SiO the thin films had a composition close to LiSiO whereas one more subcycle of LiO delivered a higher lithium content. The lithium silicate thin film prepared at 250 °C exhibited an ionic conductivity of 1.45× 10 S cm at 373 K. The high ionic conductivity of lithium silicate was due to the higher lithium concentration and lower activation energy.
固态电解质（SSE）薄膜的开发是制备全固态电池（ASSB）的关键。然而，传统的沉积技术很难以可控的方式沉积均匀和保形的 SSE 薄膜。在这项研究中，原子层沉积（ALD）被用于制备硅酸锂薄膜作为 ASSB 的潜在 SSE。使用叔丁醇锂、四乙氧基硅烷和 H 2 O 作为前体，通过组合 ALD LiO 和 SiO 亚循环来沉积硅酸锂薄膜。在 225 至 300°C 的温度下实现了均匀和自限制的生长。X 射线吸收光谱分析表明，沉积的硅酸锂由 SiO 四面体结构和氧化锂组成，作为网络修饰剂。X 射线光电子能谱证实了薄膜中 Li 的化学状态与标准硅酸锂中的相同。具有一个 LiO 和一个 SiO 亚循环的薄膜组成接近 LiSiO，而一个以上的 LiO 亚循环则提供了更高的锂离子含量。在 250°C 下制备的硅酸锂薄膜在 373 K 时表现出 1.45×10 S cm 的离子电导率。硅酸锂的高离子电导率归因于更高的锂离子浓度和更低的活化能。
