Composite Artificial SEI Layers for Lithium Metal Anodes: Suppressing Dendrite Growth and Enhancing Cycling Stability

초록

Lithium metal is a promising anode candidate for next-generation high-energy- density lithium batteries due to its lightweight nature, high theoretical capacity (3,860 mAh g?1), and low electrochemical potential. However, challenges such as uneven lithium deposition, unstable solid electrolyte interphase (SEI), and significant volumetric changes during cycling hinder its practical application and must be addressed. To overcome these challenges, we developed a composite artificial SEI layer comprising lithium fluoride (LiF) and Prussian Blue (PB) nanoparticles. LiF forms a chemically stable passivation layer with high ionic conductivity, reducing parasitic reactions and enhancing lithium-ion transport. Its mechanical robustness reinforces the SEI structure against cycling-induced stresses. PB nanoparticles, with tunable particle morphology, surface area, and size, promote uniform lithium-ion distribution, reduce localized current density, and buffer volumetric changes. By optimizing these properties, the growth of lithium dendrites was effectively suppressed, leading to enhanced cycling stability and uniform lithium deposition. These findings demonstrate the potential of the composite SEI layer to suppress dendrite formation, enhance interfacial stability, and significantly improve the cycling performance of lithium metal batteries, paving the way for practical implementation in high-energy-density battery systems.