Defect Structure of Li-Doped BPO4: A Nanostructured Ceramic Electrolyte for Li-Ion Batteries

• Published in: Journal of solid state chemistry 1999-01, Vol.142 (1), p.74-79
• Main Authors: Jak, M.J.G., Kelder, E.M., Schoonman, J.
• Format: Article
• Language: English
• Subjects: Condensed matter: structure, mechanical and thermal properties; defect chemistry; Defects and impurities in crystals; microstructure; Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.); Exact sciences and technology; Inorganic compounds; Li ion electrolyte; Li-doped BPO4; nanostructured ceramic; Physics; Salts; Structure of solids and liquids; crystallography; Structure of specific crystalline solids
• ISSN: 0022-4596; 1095-726X
• DOI: 10.1006/jssc.1998.7987

In this paper the defect chemistry of Li-doped BPO4(BPO4–xLi2O, 0≤x≤0.1) is studied. This nanostructured ceramic electrolyte is used in all-solid-state Li-ion batteries. By changing the Li-doping level the influence on the crystal structure is studied and related to t he properties of the material. X-ray diffraction, Fourier-transformed infra-red spectroscopy (FT-IR),31P,11B, and7Li magic-angle-spinning solid state nuclear magnetic resonance, neutron diffraction, and inductively coupled plasma optical-emission spectroscopy measurements are used in order to study the structure. The electrical properties are studied with AC-impedance spectroscopy (AC-IS). The experimental data show that the defect structure of Li-doped BPO4can be described with two defect models, Li″B+2Li·iand V‴B+3Li·i, suggesting that the ionic conductivity takes place via interstitial Li ions.