In situ deposition and ultrahigh vacuum STM/AFM study of V2O5/Li3PO4 interface in a rechargeable lithium-ion battery

A thin-film solid-state battery was prepared with a vanadium pentoxide cath ode and a lithium phosphate electrolyte and studied in situ by ultrahigh va cuum scanning tunneling microscope/atomic force microscopy (STM/AFM). Orien tation of the (001) plane of V2O5 parallel to the substrate was detected vi a observation of the periodicity of 11.7 +/- 0.5 Angstrom, which is consist ent with the unit cell spacing in the [100] direction. Conductance of the b attery was studied locally with the probe tip of the STM/AFM in the regime of mechanical contact with a constant repulsive force. Lateral variation of contact conductance from 0.4 to 2.2 nA was detected as a function of posit ion of the tip in contact with the cathode. The device revealed an extremel y high current density of 1 A/cm(2) due to the low thickness of the electro lyte and the cathode and the concentration of electric field under the scan ning probe microscope tip. Transformation of cathode structure due to Li io n intercalation was observed in real time. (C) 2001 The Electrochemical Soc iety.