Studies on Lithium Electrode Coated with Lithium Phosphorous Oxynitride (LiPON) in Lithium Secondary Batteries

摘要

Though a lithium metal anode has a high energy density compared with a carbon insertion anode,the poor rechargeability prevents the practical use of anode materials.So in this study,the lithium electrode coated with LiPON was prepared as a negative electrode to enhance cycleability through the control of solid electrolyte interface (SEI) layer formation in Li secondary batteries.The LiPON layer was fabricated on Li electrode by RF magnetron sputtering.The electrochemical characteristics of the SEI layer were examined using chronopotentiometry and impedance spectroscopy.In addition the lithium ion diffusion in the SEI layer of the uncoated and the LiPON-coated electrode was evaluated using chronoamperometry when lithium is immersed in electrolyte consisting of 1.0 M LiPF_6 in the mixed solvent of ethylene carbonate and diethyl carbonate.We found that the LiPON SEI layer prevented electrolyte decomposition reaction and had low interface resistance.