Dong‐Min Shin's research while affiliated with Korea Research Institute of Chemical Technology and other places

Lithium (Li) metal is widely acknowledged as the most promising anode material, owing to its high capacity and low potential. However, the practical implementation of Li faces challenges, including uncontrollable dendritic growth and a deficient solid electrolyte interphase (SEI). Here a straightforward method is provided for fabricating Li composites using Al‐doped Li7La3Zr2O12 particles (Li/LLZO) with high Li‐ion conductivity achieved using a mechanical kneading process. The optimized composite, with 20% LLZO content (Li/LLZO‐20), effectively regulates the Li‐ion flux, successfully suppressing Li dendritic growth. Using a systematic investigation, it is demonstrated that incorporating LLZO particles significantly accelerates Li‐ion migration at the electrode–electrolyte interface, facilitating smooth transport through the LLZO particles. Consequently, Li‐metal battery and Li–S battery cells utilizing the Li/LLZO‐20 composite anode exhibit remarkable cycle stability compared to cells employing pure Li anodes.

Separators play an essential role in lithium (Li)-based secondary batteries by preventing direct contact between the two electrodes and providing conduction pathways for Li-ions in the battery cells. However, conventional polyolefin separators exhibit insufficient electrolyte wettability and thermal stability, and in particular, they are vulnerable to Li dendritic growth, which is a significant weakness in Li-metal batteries (LMBs). To improve the safety and electrochemical performance of LMBs, Al2O3 nanoparticles and nanocellulose (NC)-coated non-woven poly(vinylidene fluoride)/polyacrylonitrile separators were fabricated using a simple, water-based blade coating method. The Al2O3/NC-coated separator possessed a reasonably porous structure and a significant number of hydroxyl groups (-OH), which enhanced electrolyte uptake (394.8%) and ionic conductivity (1.493 mS/cm). The coated separator also exhibited reduced thermal shrinkage and alleviated uncontrollable Li dendritic growth compared with a bare separator. Consequently, Li-metal battery cells with a LiNi0.8Co0.1Mn0.1O2 cathode and an Al2O3/NC-coated separator using either liquid or solid polymer electrolytes exhibited improved rate capability, cycle stability, and safety compared with a cell with a bare separator. The present study demonstrates that combining appropriate materials in coatings on separator surfaces can enhance the safety and electrochemical performance of LMBs.