Unique thermal conductivity, Young’s modulus and local structure of 72SnO–28P<sub>2</sub>O<sub>5</sub> glass

Abstract

Tin-phosphate (SnO–P2O5) glasses with high SnO contents have a high potential for new lead-free low-melting sealing frits, optical materials, and anode active materials for rechargeable lithium ion batteries (LIBs). The local structure (Raman scattering and 119Sn Mössbauer spectra), some physical properties (specific heat and thermal conductivity), and elastic properties (Young’s modulus and Vickers hardness) of 72SnO.28P2O5 glass were characterized to clarify the features of SnO–P2O5 glasses. The glass showed unique properties when compared with other phosphate glasses, i.e., small thermal diffusivity and conductivity, small Young’s modulus, intense Boson peak, and unique local structure. 72SnO.28P2O5 glass has an open structure with a low packing density, in which a large number of Q1 ((PO3.52−) and Q0 (PO43−) units are formed. These structural features would be one of the main reasons for the fast diffusion of Li+ ions and result in the excellent LIB performance as anode materials of the glass.