Tracking the phase transformation and microstructural evolution of Sn anode using operando synchrotron X-ray energy-dispersive diffraction and X-ray tomography  

作　　者：Kang Dong Fu Sun Andre Hilger Paul H.Kamm Markus Osenberg Francisco Garcia-Moreno Ingo Manke 

机构地区：[1]Institute of Applied Materials,Helmholtz-Zentrum Berlin fur Materialien und Energie,Hahn-Meitner-Platz 1,Berlin 14109,Germany [2]Institute of Materials Science and Technology,Technische Universitat Berlin,Hardenbergstraβe 36,Berlin 10623,Germany [3]Qingdao Institute of BioEnergy and Bioprocess Technology,Chinese Academy of Sciences,189 Songling Road,Qingdao 266101,Shandong,China

出　　处：《Journal of Energy Chemistry》2023年第1期429-437,I0011,共10页能源化学（英文版）

基　　金：sponsored by the Helmholtz Association,the China Scholarship Council(CSC);partially funded by the German Research Foundation,DFG(Project No.MA 5039/4-1)。

摘　　要：Tin(Sn)holds great promise as an anode material for next-generation lithium(Li)ion batteries but suffers from massive volume change and poor cycling performance.To clarify the dynamic chemical and microstructural evolution of Sn anode during lithiation and delithiation,synchrotron X-ray energydispersive diffraction and X-ray tomography are simultaneously employed during Li/Sn cell operation.The intermediate Li-Sn alloy phases during de/lithiation are identified,and their dynamic phase transformation is unraveled which is further correlated with the volume variation of the Sn at particle-and electrode-level.Moreover,we find that the Sn particle expansion/shrinkage induced particle displacement is anisotropic:the displacement perpendicular to the electrode surface(z-axis)is more pronounced compared to the directions(x-and y-axis)along the electrode surface.This anisotropic particle displacement leads to an anisotropic volume variation at the electrode level and eventually generates a net electrode expansion towards the separator after cycling,which could be one of the root causes of mechanical detachment and delamination of electrodes during long-term operation.The unraveled chemical evolution of Li-Sn and deep insights into the microstructural evolution of Sn anode provided here could guide future design and engineering of Sn and other alloy anodes for high energy density Li-and Na-ion batteries.

关 键 词：Sn anode Li-Sn phase transformation X-ray tomography Operando X-ray diffraction Anisotropic displacement Digital volume correlation(DVC) 

分 类 号：TM91[电气工程—电力电子与电力传动]