Understanding the Surface Passivation and Crystallographic Orientation Effects of Commercial Lithium Metal Anodes on Battery Performance

Lithium (Li) metal is one of the most promising anode materials for next-generation batteries. However, the absence of standards for manufacturing and performance assessment remains a major obstacle to the commercialization of lithium–metal batteries. In this study, 5 commercial lithium anodes are systematically investigated to reveal their key physical and chemical nonuniformities, such as variations in surface roughness, elemental composition, surface passivation species, and crystallographic orientation. We develop a structure–property correlation linking these nonuniformities to the battery performance. During manufacturing and storage, passivation species such as Li2O, LiOH, and Li2CO3 inevitably form on the lithium surface. Among them, Li2O and LiOH layers deteriorate the quality of the subsequently formed solid electrolyte interphase (SEI), while Li2CO3 facilitates the formation of a more stable and uniform SEI. The (110)-textured Li facilitates uniform lithium deposition because of the substrate effect. It is found that an ideal Li anode should possess a metallic/Li2CO3-passivated surface and (110) out-of-plane texture, which is confirmed by Li||NCM811 full cells. This study establishes a correlation between the nonuniformities of lithium anodes and their electrochemical performance, highlighting the urgent need for standardized manufacturing and evaluation protocols.