Li Metal Morphology Densification by Induction Heating for Enhanced Battery Performance Members

PIs: Renee Zhao (Mechanical Engineering), Yi Cui (Material Science Engineering)

Student and Postdoc: Yilong Chang (Mechanical Engineering), Yucan Peng (Material Science Engineering)

The lithium (Li) metal anode is considered as an ideal anode material due to its highest theoretical capacity, low density, and lowest electrochemical potential. However, the chemical heterogeneity and the instability of solid electrolyte interface (SEI) layer is generally believed to induce nonuniform ion flux, causing Li dendrites formation, which can cause internal battery shorting, which leads to poor columbic efficiency and limited cycle life. In this project, we propose a non-invasive way to manipulate Li metal morphology during battery cycling for improved battery performance through induction heating. Due to the extremely fast heating rate, it is expected that the heating of the Li metal anode can merge Li filaments, and the Li morphology can be modified with enhanced homogeneity. As a result, the negative effects on Li metal batteries resulted from Li dendrites are possibly eliminated. Moreover, the advantage of contactless exterior induction heating ensures the morphology regulation can be applied at any stage of battery cycling. For this project, we will apply induction heating for intact cells and evaluate their performance after thermal treatment. Induction heating for whole cells composed of electrodes, separator, electrolyte and battery packaging will be conducted to study Li metal morphology control. SEM will be employed for Li metal surface morphology characterization; Focused ion beam (FIB) will be utilized to observe cross-section morphology of Li metal; X-ray photoelectron spectroscopy (XPS) will be used to analyze SEI composition with heating treatment; Columbic efficiency and impedance will be measured for heated cells to validate battery performance improvement.