Structure, dielectric properties of low-temperature-sintering BaTiO₃-based glass–ceramics for energy storage

Abstract

The 0.85BaTiO 3 –0.15Bi(Mg[Formula: see text]Nb[Formula: see text])O 3 (BTBMN) ceramics with low-melting-temperature B 2 O 3 –Na 2 B 4 O 7 –Na 2 SiO 3 (BNN) glass addition were prepared by the solid state method. The composition of the glass–ceramics was BTBMN–[Formula: see text] wt.% BNN ([Formula: see text], 1, 3, 5, 7, 9, 12, 15; abbreviated as BG). The sintering characteristics, phase structure, microstructure, dielectric properties and energy storage properties were systematically investigated. The sintering temperature of BTBMN ceramics was greatly reduced by the addition of BNN glass. The second-phase BaTi(BO[Formula: see text] was observed in the BG system until the glass content reached 15[Formula: see text]wt.%. The addition of BNN glass significantly reduces the grain size of BTBMN ceramics. With the increase of BNN glass content, dielectric constant of BG glass–ceramics at 1[Formula: see text]kHz gradually decreased, the maximum dielectric constant ([Formula: see text] of BG glass–ceramics gradually decreased, while the temperature corresponding to the maximum dielectric constant ([Formula: see text] increased, the ferroelectric relaxation behavior decreased and the temperature stability of the dielectric constant gradually improved. As the BNN glass content increased, the breakdown electric field strength (BDS) of BG glass–ceramics increased first and then decreased, and the polarization values reduced gradually, while the trend of energy storage performance is similar to BDS. When the BNN glass content was 3[Formula: see text]wt.%, the energy storage properties of the BG glass–ceramics were optimal, and a recoverable energy storage density ([Formula: see text]) of 1.26[Formula: see text]J/cm 3 and an energy storage efficiency ([Formula: see text]) of 80.9% were obtained at the electric field strength of 220[Formula: see text]kV/cm. The results showed that BG glass–ceramics were promising for energy storage capacitors.