Preparation of Bulk Na2O-BaO-PbO-Nb2O5-SiO2 Glass-Ceramic Dielectrics for Energy Storage Sources

Bulk Na2O-BaO-PbO-Nb2O5-SiO2 glass-ceramic dielectrics in considerable size (about 200x100x5mm3) were prepared via controlled-crystallization route. The dielectric properties (including the permittivity and the loss tangent) of the bulk dielectrics were investigated. The results show that the capability of charge or energy storage in the bulk dielectrics is relatively lower than that of anticipation based on thinner and smaller specimen, due to the serious breakdown strength (BDS) drop of the bulk dielectrics. Several electrode structures were designed and applied in the measurement circuit to enhance the BDS of the bulk dielectrics. Among which, a bowl-like electrode structure was proved to reduce electrode edge effect most effectively in the BDS measurement.