The Development of a High Specific Energy, Secondary Solid State, Thin-Film, Li202/Li Battery

A lithium peroxide/lithium battery has a theoretical specific energy of 2569 W.hr/kg, far higher than any secondary battery available or under development. A solid-state, thin-film version of this battery has been an area of research for several years and is proposed for development. The electrolyte used is based on polyethylene oxide, and is a conductor of Li+ ions. The cathode is a composite of lithium peroxide, polyethylene oxide, and carbon black. Preliminary experiments with this cell have shown that reversibility is possible. Thin-film cells built to this point have been capable of 40 charge/discharges cycles, and indications are that many more are achievable. Current densities of 0.1 mA/cm2 were sustained during these discharges. The measure open circuit potentials correspond with the 2.86 V theoretical value for the Li202/Li couple. Anticipated Benefits: The successful completion of this work will lead to batteries which will find a wide variety of uses where high specific energy, environmental compatibility, wide temperature range, and safety are a concern. Some of these are man-portable military systems, electronics, and medical implants, and space applications, and electric vehicle transportation.