Laboratory for Molecular Physics and Synthesis of New Materials, Ruder Bošković Institute, Bijenička c. 54, 10000 Zagreb, Croatia.
Research Unit New Functional Materials, Center of Excellence for Advanced Materials and Sensing Devices, Bijenička c. 54, 10000 Zagreb, Croatia.
Molecules. 2020 Feb 17;25(4):891. doi: 10.3390/molecules25040891.
Commercial micrometer silicon (Si) powder was investigated as a potential anode material for lithium ion (Li-ion) batteries. The characterization of this powder showed the mean particle size of approx.75.2 nm, BET surface area of 10.6 mg and average pore size of 0.56 nm. Its band gap was estimated to 1.35 eV as determined using UV-Vis diffuse reflectance spectra. In order to increase the surface area and porosity which is important for Li-ion batteries, the starting Si powder was ball-milled and threatened by metal-assisted chemical etching. The mechanochemical treatment resulted in decrease of the particle size from 75 nm to 29 nm, an increase of the BET surface area and average pore size to 16.7 m/g and 1.26 nm, respectively, and broadening of the X-ray powder diffraction (XRD) lines. The XRD patterns of silver metal-assisted chemical etching (MACE) sample showed strong and narrow diffraction lines typical for powder silicon and low-intensity diffraction lines typical for silver. The metal-assisted chemical etching of starting Si material resulted in a decrease of surface area to 7.3 m/g and an increase of the average pore size to 3.44 nm. These three materials were used as the anode material in lithium-ion cells, and their electrochemical properties were investigated by cyclic voltammetry and galvanostatic charge-discharge cycles. The enhanced electrochemical performance of the sample prepared by MACE is attributed to increase in pore size, which are large enough for easy lithiation. These are the positive aspects of the application of MACE in the development of an anode material for Li-ion batteries.
商用微米硅（Si）粉末被研究作为锂离子（Li-ion）电池的潜在阳极材料。该粉末的特性表明其平均粒径约为 75.2nm，BET 表面积为 10.6mg，平均孔径为 0.56nm。其带隙通过紫外可见漫反射光谱确定为 1.35eV。为了增加表面积和孔隙率，这对锂离子电池很重要，起始 Si 粉末经过球磨和金属辅助化学刻蚀处理。机械化学处理导致粒径从 75nm 减小到 29nm，BET 表面积和平均孔径分别增加到 16.7m/g 和 1.26nm，X 射线粉末衍射（XRD）线变宽。银金属辅助化学刻蚀（MACE）样品的 XRD 图谱显示出典型的粉末硅的强而窄的衍射线和典型的银的低强度衍射线。起始 Si 材料的金属辅助化学刻蚀导致表面积减小到 7.3m/g，平均孔径增加到 3.44nm。这三种材料都被用作锂离子电池的阳极材料，并通过循环伏安法和恒电流充放电循环研究了它们的电化学性能。MACE 制备的样品增强的电化学性能归因于孔径的增加，这对于易于嵌锂来说足够大。这些是在锂离子电池开发中应用 MACE 的积极方面。
