The Li2O-B2O3 quasi-binary system is assessed. A two-sublattice ionic solut
ion model, (Li1+)(P)(O2-, BO33-, B4O72-, B3O4.5)(Q), is adopted to describe
the liquid phase, All solid phases are treated as stoichiometric compounds
. A set of parameters consistent with most of the available experimental da
ta on phase diagram and thermodynamic properties is obtained by using the C
ALPHAD technique.