Enhancement of energy storage and pyroelectric properties of (Na0.5Bi0.5)TiO3-SrTiO3-BaTiO3 ceramics by addition of (Ba0.9B0.1)TiO3 glass-phase

Abstract

The present study introduces a novel analysis of the effect of the glass phase on the energy storage and the pyroelectric properties of 0.65(Bi0.5Na0.5)TiO3-0.25SrTiO3–0.1BaTiO3 (abbreviate NBT-ST-BT) lead-free ceramics. The glass phase was prepared by melt-quenching of (Ba0.9B0.1)TiO3 (BBT) calcined powder. Different content of BBT glass phase was introduced into the ceramic matrix [(1-x)(NBT-ST-BT)—x(BBT)] (x = 0.0, 2.5, 5, 7.5 and 10%) solid solution. The crystal structure shows rhombohedral and orthorhombic coexistence phases, increasing the R-phase volume fraction by increasing BBT glass content. The grain size was suppressed to a sub-micrometer by increasing the BBT glass amount, denoting the enhanced dielectric breakdown strength (BDS). The most significant recoverable energy storage density (Wrec = 2.5 J cm−3) with the highest energy storage efficiency (η ∼ 87%) has been obtained at 200 kV cm−1 of BBT 5%. The variation in Wrec of the optimum sample is less than 4% from 25 °C to 150 °C, indicating the high thermal stability of energy storage properties. The pyroelectric coefficient (PE) was estimated using an approximate numerical method of differentiating remnant polarization Pr concerning temperature. Adding the BBT glass phase enhanced the pyroelectric properties and figure of merit (FOM). The FOM increased from 7 × 10−10 to 8 × 10−10 C/cm2. °C at T = 150 °C when glass content increased from 0.0 to 0.1. These results prove that the addition of the BBT glass phase resolves the difference between high energy storage properties and lower sintering temperatures of ceramic materials, enhancing the pyroelectric properties for practical applications.