Lithium-ion battery technology revolutionized the portable electronics landscape. However, there is an increasing need for more advanced energy storage technologies, which the current batteries can no longer deliver. Despite the logical transition to using metallic lithium (Li) as an anode, the many problems associated with metallic Li mean that this transition is not evident. Due to the strong reducing potential of Li, the interface between the electrode and the electrolyte changes into an unstable environment. This dramatically reduces the battery lifetime. Applying protective coatings on the Li surface, for example, by atomic layer deposition (ALD), has been reported to enhance the surface properties of Li. Yet, insights in the surface chemical processes during such modifications are lacking, hampering an optimization of the surface and coating properties. In this project, the role of the native oxide layer present on as-received, commercial Li will be investigated. Starting from recently developed plasma cleaning treatments, Li will be exposed to different gases to form a stable and more reproducible surface. Afterward, these newly formed surfaces will be used to create thin, protective coatings with ALD. New coatings with a high ionic conductivity and a broad electrochemical stability will be developed to extend the battery lifetime. This research aims to broaden the knowledge about stabilizing the Li surface through surface treatments and ALD coatings.