Surface Characterization of LiFePO4 Epitaxial Thin Films by X-ray/Neutron Reflectometry

Abstract

The electrode surface of a lithium battery was characterized using in situ reflectivity techniques and epitaxial thin films. Epitaxial LiFePO4 thin films were fabricated by pulsed laser deposition. Changes in interfacial structures on the surface are determined by X-ray and neutron reflectivity (NR) measurements using an X-ray-transmission electrochemical cell. The LiFePO4 surface is stable during the first charge/discharge process. NR analysis indicates a reversible change in the concentration gradient of lithium ions at the LiFePO4/electrolyte interface on lithium deintercalation.