Local Structure of Glassy Lithium Phosphorus Oxynitride Thin Films: A Combined Experimental and Ab Initio Approach |
| |
| Authors: | Maxwell A T Marple Thomas A Wynn Diyi Cheng Ryosuke Shimizu Harris E Mason Prof Y Shirley Meng |
| |
| Institution: | 1. Physical and Life Science Directorate, Lawrence Livermore National Laboratory, Livermore, CA, 94550 USA;2. Department Department of NanoEngineering, University of California San Diego, La Jolla, CA, 92093 USA;3. Materials Science & Engineering Program, University of California San Diego, La Jolla, CA, 92093 USA |
| |
| Abstract: | Lithium phosphorus oxynitride (LiPON) is an amorphous solid-state lithium ion conductor displaying exemplary cyclability against lithium metal anodes. There is no definitive explanation for this stability due to the limited understanding of the structure of LiPON. Herein, we provide a structural model of RF-sputtered LiPON. Information about the short-range structure results from 1D and 2D solid-state NMR experiments. These results are compared with first principles chemical shielding calculations of Li-P-O/N crystals and ab initio molecular dynamics-generated amorphous LiPON models to unequivocally identify the glassy structure as primarily isolated phosphate monomers with N incorporated in both apical and as bridging sites in phosphate dimers. Structural results suggest LiPON′s stability is a result of its glassy character. Free-standing LiPON films are produced that exhibit a high degree of flexibility, highlighting the unique mechanical properties of glassy materials. |
| |
| Keywords: | ab initio calculations GIPAW LiPON solid electrolytes solid-state NMR spectroscopy |
|
|
