Electrochemical Decalcification–Exfoliation of Two-Dimensional Siligene, Si x Ge y : Material Characterization and Perspectives for Lithium-Ion Storage

作者：Evgeniya Kovalska, Bing Wu, Liping Liao, Vlastimil Mazánek, Jan Luxa, Ivo Marek, Luc Lajaunie, Zdeněk Sofer · 发表于：ACS Nano · 年份：2023 · DOI：10.1021/acsnano.3c00658 · 被引用次数：18 · 研究领域：Advancements in Battery Materials、Graphene research and applications、Supercapacitor Materials and Fabrication

High Resolution Image Download MS PowerPoint Slide A two-dimensional (2D) silicene–germanene alloy, siligene (Si x Ge y ), a single-phase material, has attracted increased attention due to its two-elemental low-buckled composition and unique physics and chemistry. This 2D material has the potential to address the challenges caused by low electrical conductivity and the environmental instability of corresponding monolayers. Yet, the siligene structure was studied in theory, demonstrating the material’s great electrochemical potential for energy storage applications. The synthesis of free-standing siligene remains challenging and therefore hinders the research and its application. Herein we demonstrate nonaqueous electrochemical exfoliation of a few-layer siligene from a Ca 1.0 Si 1.0 Ge 1.0 Zintl phase precursor. The procedure was conducted in an oxygen-free environment applying a −3.8 V potential. The obtained siligene exhibits a high quality, high uniformity, and excellent crystallinity; the individual flake is within the micrometer lateral size. The 2D Si x Ge y was further explored as an anode material for lithium-ion storage. Two types of anode have been fabricated and integrated into lithium-ion battery cells, namely, (1) siligene–graphene oxide sponges and (2) siligene–multiwalled carbon nanotubes. The as-fabricated batteries both with/without siligene exhibit similar behavior; however there is an increase in the electrochemical characteristics of SiGe-integrated batter...