Synthesis Optimisation of Lithium Phosphorus Oxinitride (LiPON) from the Elements

The development of solid state lithium ion batteries is predicted to provide a step change in performance compared to state of the art lithium ion batteries. The benefits of solid state batteries include increased thermal stability, simple construction and increased energy densities. The reduced footprint and increased energy densities of solid state batteries are ideal for powering remote wireless sensors such as those proposed for the ever expanding Internet of Things. State-of-the-art solid state lithium micro-batteries use LiPON as the solid electrolyte. The synthesis of LiPON is only possible via the sputtering of lithium ortho-phosphate targets in nitrogen plasma but this method has serious limitations. This study will deposit thin films of LiPON with demonstrable control over the ratio of nitrogen to oxygen incorporated into the films and ion conductivities comparable, or superior to those of materials prepared using state-of-the-art deposition methods.