Hu Chih-Wei, Chou Jyh-Pin, Hou Shang-Chieh, Hu Alice, Su Yu-Fan, Chen Tsan-Yao, Liew Wing-Keong, Liao Yen-Fa, Huang Jow-Lay, Chen Jin-Ming, Chang Chia-Chin
Department of Engineering and System Science, National Tsing Hua University, Hsinchu, 30013, Taiwan.
Department of mechanical and biomedical engineering, City University of Hong Kong, Kowloon, Hong Kong SAR.
Sci Rep. 2019 Feb 4;9(1):1299. doi: 10.1038/s41598-018-38112-2.
Artificial graphite (FSN) additive is employed as internal structural label for projecting cyclability of Si material native electrode in a mass ratio of Si/FSN = 1.0 in Li ion battery (LIB). Results of operando X-ray diffraction analysis on Si-FSN negative electrode in LIB demonstrate that one can evaluate the lithiation and delithiation affinity of active material by referring phase transition delay of graphite as affected by experimental splits in a formation process of LIB. We prove that a thin layer of surface amorphous structure and residual lattice strain are formed in Si by high energy ball-milling treatment. Those manipulations improve Li intercalation kinetics and thus enabling a capacity fading of less than 10% (from 1860 to 1650 mAhg) for Si negative electrode in 50 cycles. Of utmost importance, this study discloses a robust assessment for revealing mechanism on amorphous and strain related silicide formation and predicting cyclability of negative electrode by quantitative phase evolution rate of FSN additive in LIB.
人造石墨（FSN）添加剂被用作内部结构标记，以突出锂离子电池（LIB）中硅材料原生电极的循环性能，在锂离子电池中硅与FSN的质量比为Si/FSN = 1.0。对锂离子电池中Si-FSN负极进行的原位X射线衍射分析结果表明，通过参考在锂离子电池形成过程中实验分割对石墨相变延迟的影响，可以评估活性材料的锂化和脱锂亲和力。我们证明，通过高能球磨处理，硅中形成了一层薄的表面非晶结构和残余晶格应变。这些操作改善了锂嵌入动力学，从而使硅负极在50次循环中的容量衰减小于10%（从1860降至1650 mAh/g）。至关重要的是，本研究揭示了一种强大的评估方法，通过锂离子电池中FSN添加剂的定量相演化速率来揭示非晶态和应变相关硅化物形成的机制，并预测负极的循环性能。
