LI Zhipeng, LI Dongxu, SHEN Zongyang, LUO Wenqin, SONG Fusheng, WANG Zhumei, LI Yueming
(School of Material Science and Engineering, Jingdezhen Ceramic University; China National Light Industry Key Laboratory of Functional Ceramic Materials; Energy Storage and Conversion Ceramic Materials Engineering Laboratory of Jiangxi Province, Jingdezhen 333403, Jiangxi, China)
Abstract: (Bi0.5Na0.5)0.65(Ba0.3Sr0.7)0.35[(Zn1/3/Nb2/3)xTi1–x]O3 (BNBST–ZN100, x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) ceramics were prepared by using solid state reaction method. The effect of (Zn1/3/Nb2/3)4+ complex on phase structure, microstructure, dielectric properties and energy storage characteristics of the ceramics was studied. It was found that the BNBST–ZN100x ceramics had a single phase pseudo-cubic structure, with an average grain size of 1.1 μm and clear visible grain boundaries. With increasing x value, the dielectric peak was gradually suppressed and broadened, indicating that the (Zn1/3/Nb2/3)4+ modification effectively enhanced the dielectric temperature stability of the BNBST ceramics. The combined effect of the volatilization of Bi and Na and oxygen vacancies at high temperatures may be the cause of the conductive mechanism of the BSBNT–ZN100x ceramics, while the oxygen vacancy conduction played a leading role with the presence of ZN. The P–E loops of BNBST–ZN100x ceramics were gradually changed to slim type with increasing x value. The sample with x = 0.08 exhibited a maximum energy storage density of Wrec = 1.3 J/cm3 at electric field of 110 kV/cm, together with a high energy storage efficiency of = 94%. In addition, over the temperature range of 30-150 ℃ after 105 electric cycles, the energy storage properties showed a high stability and strong fatigue endurance, which can be a promising candidate as pulsed power ceramic capacitors.
Key words: energy storage ceramics; sodium bismuth titanate; relaxor ferroelectrics; ceramic capacitor