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The crystallization kinetics,microstructures,dielectric properties and energy storage properties of strontium barium niobate based glass--ceramics have been studied as a function of the BaF2/La2O3 concentration.The addition of BaF2 to the glass-ceramics decreases the activation energy of crystallization and enhances the dielectric constant as well as breakdown strength remarkably.Glass-ceramic with a dielectric constant of 63.4,breakdown strength of 1120kV/mm and energy storage density of 3.52J/cm3 could be achieved.A new electrode structurecould effectively improve the electrical properties,and energy storage density could be increased from 3.52 J/cm3 to4.82 J/cm3.As for La2O3 added glass-ceramics,only single phase determined as Sr0.5Ba0.5Nb2O6is formed for all glass-ceramics.The dielectric breakdown strength(BDS)strongly depends on the interface activity energy.Although the dielectric constantis decreased continuously,the dielectric loss tangentis well controlled below 0.01,and the BDS increases from 608 to 1127 kV/cm for the glass-ceramics withincreasing La2O3 addition.The maximum theoretical energy-storage density of 7.1J/cm3could be achieved in the glass-ceramic with0.5 mol%La2O3 addition,which was improved by 2.7 times as compared with that of the pure glass ceramic.This study provided the BaF2/La2O3added lead-free niobate glass-ceramic as an attractive candidatefor making high-energy density capacitors.