Preparation And Dielectric Energy Storage Of Ce Doping SrTiO₃-based Energy Storage Ceramics

SrTiO₃ based energy storage dielectric ceramics have great potential in the study of high energy density materials,as high breakdown strength and dielectric loss and low.I can improve their energy density by the enhancement of breakdown strength and dielectric constant based on low dielectric loss.Previous studies show thatdifferent microstructure,phase structure,dielectric and energy storage properties presented in trace rare earth doped ceramics.This paper focus on improving the energy storage properties of SrTiO₃ based ceramics.The rare earth element Ce and polar oxide MgO were selected as doping agent to enhance the dielectric constant and breakdown strength,so as to improve their storage performance.SrTiO₃ based ceramics were prepared by traditional ceramic solid-phase method.First,I explored the effects of Ce doping on sintering properties,crystal structure,microstructure properties,dielectric properties and breakdown strength.The XRD pattern analysis shows that a small amount of Ce doping does not appear obvious the second phase,because small amount of Ce into the lattice.With the increase of Ce content,the dielectric constant of Sr_1-3/2xCe_xTiO₃ ceramics（x=0.005,0.010,0.015,0.020）first increased followed by a decrease.When x=0.010,the dielectric constant dramatically increased from 300 for pure SrTiO₃ to 2513,and the dielectric loss（0.8%）.Optimized breakdown strength E_b=17.94kV/mm and recharge energy storage density 0.897J/cm3 were achieved at x=0.015.Second,I discussed the impact of oxygen treatment on microstructure,dielectric properties and storage properties of Sr_1-3/2xCe_xTiO₃.The variation of dielectric constant of oxygen treated Sr_1-3/2xCe_xTiO₃ ceramics as same as untreated ceramics.The maximum dielectric constantε_r=754 was achieved at x=0.010,while dielectric loss don’t change.Breakdown strength E_b and energy density were significantly improved by oxygen treatment.When x=0.010,the sample possesses maximum E_b=22.4kV/mm,energy storage density is 1.33J/cm3 and energy storage efficiency96.37%.Finally,active agent MgO was introduced to Sr_0.985Ce_0.010TiO₃(x wt%MgO+（1-x）wt%Sr_0.985Ce_0.010TiO₃,note as x wt%MgO+（1-x）wt%SCT).The addition of MgO slightly enhanced the breakdown strength of the system.Energy storage density first increased then decreased with increasing MgO content.Too much MgO content deteriorated energy storage efficiency.When x=1.0,breakdown strength Eb is18.71kV/mm and energy storage density is 0.51J/cm³.