AIM (Advanced Integrated Materials, 차세대융합소재연구실)

논문 초록 (Abstract)

Today, lithium secondary batteries are heavily involved in our daily life. The electric vehicle market is gradually expanding, and the demands for electric vehicles with increased driving mileage are also increasing. To meet the requirements of long-mileage electric vehicles, a battery with a large energy density must be adopted. Considering this, metallic Li, which has a high theoretical capacity and lowest potential, is the most promising anode material. Nevertheless, Li metal anodes have several problems, such as the formation of dendritic Li and deterioration of Li metal battery capacity in repeated cycles. Internal short circuit and explosion of the battery can occur by dendritic Li resulting from non-uniform deposition on the Li metal electrode. Therefore, recent research has been conducted regarding the effective methods to control the electrodeposition behavior of Li. Lithium metal powder (LiMP) with a large surface area effectively suppresses dendritic growth. Here, we try to maximize the performance of LiMP electrodes by adding AgNO3. Ag forms uniform electrodeposition of Li by setting nucleation sites across the broad LiMP electrode surface. Also, an excellent Li-ion conductor, Li3N particles are formed by Li metal and AgNO3 reactions. When dendritic Li is formed and comes into contact with Li3N, it controls the growth direction of the dendrite. To confirm the effect of AgNO3 on the performance of the electrodes, the symmetric cell test, impedance test, SEM (Scanning Electron Microscopy), and XPS (X-ray Photoelectron Spectroscopy) were implemented. In the case of the electrode with AgNO3, we confirm that dendritic Li growth was relatively suppressed, and the overpotential also decreased in the Li/Li symmetry cell test.