DescriptionToday the lithium and lithium-ion batteries represent the premiere high energy density battery. Beyond improving performance, there is a desire to reduce cost of manufacture and enable battery technology to adapt conformally to a variety of operating environments. Recently Rutgers introduced a concept of electrolytically formed batteries (EFBs) as a type of self-assembled approach where the entire anode and cathode is formed in-situ on the atomic level. EFBs have the potential to offer a unique pathway to much lower cost cell manufacture (no electrodes, no lithium metal to handle), a non lithium metal containing reserve cell, and to form batteries in very demanding architectures such as those dictated by advanced 3-D battery designs. This thesis represents the first comprehensive research related to lithium EFBs, specifically one based on LiI. Specific focus on the structure and ionic and electronic transport of in-situ formed polyiodide networks will be discussed along with the key role of stabilizing interphases.