Spatial atomic layer deposition of LiPON thin films

Abstract

In the last few years, with the advance of electrical vehicles and number of devices needing safe batteries especially in the medical field, a more efficient way to store energy is necessary. Despite the fact that conventional lithium batteries present high conductivity values, they do not exhibit enough charging/discharging speed and also include dangerous components to health. To overcome those challenges, thin film solid state batteries are considered a promising candidate. However, this all-solid-state battery concept exhibits too low energy density, pushing the technology towards 3D structures and developing 3D all-solid-state lithium-ion batteries (ASSBs). This thesis describes the development of a pinhole-free solid-state lithium-ion electrolyte through spatial, to pave the way for cost effective and scalable 3D ASSBs. The produced films are thoroughly characterized to find the relation between deposition parameters and film quality in terms of thickness, reproducibility, uniformity, composition and conductivity. The obtained LiPON, being deposited with the fast spatial ALD process, offers ionic conductivity of 1.55 (± 0.14) x 10-7 S/cm and electronic conductivity of 1.86 x 10-13 S/cm, being a promising solid electrolyte layer for next generation lithium-ion batteries.