Fluoride-containing additives, electrolytes, solid electrolyte interphases (SEI), and fluorinated materials represent a recurring motif in many proposed next-generation battery chemistries. Fluoride-enrichment at the surface of metallic anodes, such as Li, has been suggested to impart favorable stabilization of the SEI, permitting empirically enhanced round-trip efficiency and cycle life by mitigating dendrite formation. Meanwhile, fluorinated materials such as oxyfluoride intercalation cathodes, fluorinated carbons in primary battery cathodes, and metal fluoride conversion cathodes represent distinct approaches to tailor the behavior of bulk materials. In spite of this promise, precisely manipulating fluoride-based materials and reaction mechanisms remains challenging. In this talk, I describe our group’s exploration of several applications where fluoride-forming reactions can be tailored and harnessed for application in primary and secondary batteries. First, I describe our efforts to develop high-energy density primary batteries based on the electrochemical reduction of fluorinated gases. We show that fundamental knowledge and the experimental framework developed in the field of Li-oxygen batteries in recent years can be successfully translated to the development of new gas-to-solid conversion reactions with high energy densities. Molecular transformation mechanisms occurring during the discharge reactions, which involve atypically high electron transfer numbers (2<n<8), will be presented, and future strategies to improve power density of gas-based conversion systems will be discussed. Then, we shift gears to focus on how fluorinated reactions can be harnessed to modify metal interfaces. We discuss our findings on the reactivity of fluorinated gases with Li surfaces in the development of so-called “artificial SEI” layers on Li, and critically examine the role of LiF in imparting stability to modified interfaces. Finally, we highlight future challenges and opportunities in the modification of cathode materials enriched with fluoride derived from our gas-based reaction architecture.