Elomari Ghizlane, Hdidou Loubna, Larhlimi Hicham, Aqil Mohamed, Makha Mohammed, Alami Jones, Dahbi Mouad
Materials Science, Energy and Nano-engineering Department, Mohammed VI Polytechnic University, Lot 660-Hay Moulay Rachid, 43150 Ben Guerir, Morocco.
ACS Appl Mater Interfaces. 2024 Jan 17;16(2):2193-2203. doi: 10.1021/acsami.3c12056. Epub 2024 Jan 2.
Amorphous Si thin films with different thicknesses were deposited on synthetic graphite electrodes by using a simple and scalable one-step physical vapor deposition (PVD) method. The specific capacities and rate capabilities of the produced electrodes were investigated. X-ray diffraction, scanning electron microscopy, Raman spectroscopy, profilometry, cyclic voltammetry, galvanostatic techniques, and in situ Raman spectroscopy were used to investigate their physicochemical and electrochemical properties. Our results demonstrated that the produced Si films covered the bare graphite electrodes completely and uniformly. Si-coated graphite, Si@G, with an optimal thickness of 1 μm exhibited good stability, with an initial discharge capacity of 628.7 mAhg, a capacity retention of 96.2%, and a columbic efficiency (CE) higher than 99% at C/3. A discharge capacity of 250 mAh g was attained at a high current rate of 3C, which was over 2.5 times that of a bare graphite electrode, thanks to the high activated surface area (1.5 times that of pristine graphite) and reduced resistance during cycling.
采用简单且可扩展的一步物理气相沉积（PVD）方法，在合成石墨电极上沉积了不同厚度的非晶硅薄膜。研究了所制备电极的比容量和倍率性能。利用X射线衍射、扫描电子显微镜、拉曼光谱、轮廓仪、循环伏安法、恒电流技术和原位拉曼光谱来研究其物理化学和电化学性质。我们的结果表明，所制备的硅膜完全且均匀地覆盖了裸露的石墨电极。厚度为1μm的最佳硅包覆石墨（Si@G）表现出良好的稳定性，在C/3下初始放电容量为628.7 mAh/g，容量保持率为96.2%，库仑效率（CE）高于99%。在3C的高电流倍率下，放电容量达到250 mAh/g，这是裸露石墨电极的2.5倍多，这得益于高活性表面积（是原始石墨的1.5倍）以及循环过程中电阻的降低。
