Formation of N-Rich Solid Electrolyte Interphase with LiNO3 Solution for Lithium Metal Powder Batteries

Abstract

Conventional manufacturing process of Li metal anodes employs extrusion-pressing or deposition methods resulting in sheet or film-types, respectively. Considering the demands for high-gravimetric energy density, thinner Li metal is crucial for realizing the desired weight ratio of anode in Li metal batteries (LMBs). However, during the manufacturing process at high rate, there could be limitations such as Li damage or dendritic growth caused by excessive pressure or non-uniform deposition. Li metal powders (LMPs) are beneficial for fabricating thin Li anodes within a short time via a slurry coating process. Despite the advantages of LMP, the Li2CO3 passivation layer unevenly covering the LMP surface results in dendritic Li growth. Thus, modification of the passivation layer is very crucial to control the Li plating/stripping behavior. Here, we suggest a LiNO3 solution-treated LMP electrode for securing robust cyclability with low overpotential in LMBs. The dissolved LiNO3 in the LMP slurry can effectively modify the passivation layer into an N-rich SEI, enabling a uniform Li+ flux. Additionally, the well-distributed LiNO3 in the LMP anode could continuously repair the SEI during cycling via a slow-release mechanism into the carbonate-based electrolyte system. As a result, the LiNO3-treated LMP electrode effectively enhances the performance and stability of LMBs. Therefore, LiNO3 solution treatment of Li metal is an attractive approach to achieving a stable and robust SEI in LMBs.