UC San Diego

Lithium metal anodes are crucial for high-energy-density batteries, but concerns regarding their safety remain. Limited investigations have evaluated the reactivity of Li metal anodes in full cell configurations. In this study, differential scanning calorimetry (DSC) and in situ Fourier-transform infrared spectroscopy (FTIR) were employed to quantitatively examine the Li metal reactivity. Lithiated graphite (Li-Gr) and lithiated silicon (Li-Si) were also compared. The reactivity of plated Li was systematically investigated when combined with different electrolyte compositions, morphologies, atmospheres, and various cathode materials (NMC622, LFP, and LNMO). It was discovered that all cell components, such as electrolyte composition, Li morphology, control of inactive Li accumulation, and cathode stability, play essential roles in regulating the reactivity of the plated Li. By optimizing these factors, the Li metal full cell exhibited no significant thermal reaction up to 400 °C. This research identifies key parameters for controlling Li metal reactivity, potentially advancing lithium metal battery design and manufacturing.