Structural Evolution during Lithiation Cycles of the Li-Au System Observed By in-Situ High-Energy x-Ray Diffraction

• DOI: 10.1149/ma2015-02/1/40
• Publication Date: 2020-02-27T01:05:03Z
• Authors: Philipp Bach; Irais Valencia-Jaime; Aldo H. Romero; Frank Uwe Renner
• Keywords: Metastability; Characterization

Recent new Li-Ion Battery (LIB) developments include alloy anodes such as Si-Li, and a general trend towards nanostructured components. With technological development LIB were proposed to store energy for stationary applications well electromobility. Batteries need become more robust achieving longer cycle lifetime in use achieve this future goal. Therefore fundamental insight into the acting atomic-scale processes structural evolution within active materials during charging, i.e. lithiation delithiation cycles is required. Crystalline phases are often formed cycling amorphous which prominently form based on Si or Ge. Due its inert nature Au has been used model material electrochemical research including Li ion storage (1,2). was employed composite example seed layers further grow nanowires coatings. For gold electrodes contained anode several studies have pointed many intermediate metastable crystalline Li-Au phases. X-ray diffraction classical non-destructive method characterize synchrotron light recently facilitated analysis of surfaces thin films in-situ in-operando characterization. Using high-energy x-ray sources complete reciprocal plain can be imaged short time scales necessary follow also quick changes time-scale few seconds. The huge benefit x-rays demonstrated detailed from catalytic surface reactions molecular interface structures layering battery processes. We describe an study (3) following alloying (charging) dealloying (de-charging) with film discuss observations result theoretical screening potential During entire charging discharging we observed total 6 different mainly so far unknown leading here chosen end state known stable 3 phase. followed cycling. grown single Cu substrates observe final cubic emerge oriented relation below substrate thus indicating phase nucleates at interface. 1. P. Bach, M. Stratmann, I. Valencia-Jaime, A. H. Romero, F. U. Renner, Lithiation Delithiation Mechanisms Gold Thin Film Model Anodes Lithium Ion Batteries: Electrochemical Characterization, Electrochimica Acta (2015), 164, 81–89. 2. F.U. Kageyama, Z. Siroma, Shikano, S. Schöder, Y. Gründer, O. Sakata, Li-ion batteries: Single systems studied by situ diffraction, Electrochim. 53 (2008), 6064-6069. 3. Rütt, Gutowski, published. Figure 1