發(fā)布時間：2018-07-01 10:14

  本文選題：鋯錫鈦酸鉛鑭 + Ba摻雜　； 參考：《北京化工大學(xué)》2015年碩士論文

【摘要】：本論以(Pb0.925-xLa0.05Bax) [Zr0.52(SnyTiZ)0.48]O3(PLZST,其中,x=0,2,4,6,8,10; y/z=39/9,35/13,32.5/15.5)反鐵電材料為研究對象,通過Ba部分取代Pb及調(diào)整Sn/Ti比例來優(yōu)化材料的微觀結(jié)構(gòu),旨在提高PLZST陶瓷材料介電性能和改善充放電壽命,進(jìn)而獲得高儲能密度的材料組成。利用SEM、XRD、介溫測試儀、電滯回線測試儀及充放電測試儀來表征材料的組成對微觀結(jié)構(gòu)、介電性能、儲能密度、儲能效率及充放電壽命的影響。為了探究材料組成如何影響充放電壽命,采用高加速老化試驗(HALT)、阻抗譜、熱刺激退極化電流(TSDC)的方法來探測引起老化的粒子類型及其在老化過程中的作用。Ba摻雜抑制了PLZST材料中焦綠石相的形成,提高了鈣鈦礦相的穩(wěn)定性。當(dāng)Ba由0增加至10 mol%時,峰值介電常數(shù)由900增加至1200,峰值溫度Tmax由145℃以4.8℃/mol%向低溫移動。充、放電儲能密度均隨Ba摻雜量的增加先增加后減小,在Ba含量為6 mol%時達(dá)到最大值,而對儲能效率影響不大。在經(jīng)歷10000次充放電后6 mol%Ba摻雜樣品的可釋放能量密度衰減8%,而未摻雜的樣品衰減25%,因此,Ba的摻雜可以改善PLZST反鐵電陶瓷樣品的充放電壽命。隨Sn/Ti比的降低,電滯回線由線性逐漸展現(xiàn)出了雙電滯回線,極化強(qiáng)度呈增加的趨勢,相變電場逐漸減小,最大極化強(qiáng)度迅速增加,使得充、放電儲能密度大幅提高。高Sn/Ti比(39/9)的樣品的可釋放能量密度在經(jīng)歷10000次充放電循環(huán)后幾乎沒有衰減,而隨Sn/Ti比由35/13繼續(xù)減少至32.5/15.5時,其衰減由13%增加至27%。綜合考慮Sn/Ti比選擇為35/13較為合適。根據(jù)PLZST樣品的HALT曲線上漏電流先隨時間緩慢增加,最后在某一時刻迅速增加,這表明PLZST樣品老化過程經(jīng)歷了先緩慢老化和隨后快速擊穿兩個過程。阻抗譜和TSDC結(jié)果表明：PLZST陶瓷樣品的老化源于在制備過程中由于氧化鉛揮發(fā)產(chǎn)生的偶極子Vpb"-Vo··,氧空位Vo··可從偶極子Vpb"-Vo··中脫陷出來,沿電場方向移動,進(jìn)而改變了PLZST陶瓷材料組成,引起了漏電流的增加。Ba摻雜不僅可以抑制偶極子Vpb"-Vo··產(chǎn)生,還阻礙了氧空位與相鄰的02-的位置交換,使得氧空位Vo··脫陷過程變得更加困難,充放電壽命延長。熱重-差熱結(jié)果表明,PLZST基多層片式陶瓷電容器的坯體的排膠需要依次經(jīng)歷殘余的有機(jī)溶劑的蒸發(fā)、低燃點有機(jī)化合物的燃燒和高燃點有機(jī)化合物的分解三個過程。緩慢升溫、在有機(jī)物燒除時保溫適當(dāng)時間,使用帶有熱風(fēng)循環(huán)系統(tǒng)的高溫烘箱,排膠時加蓋氧化鋁平板均可以減少排膠過程的翹曲和微裂紋產(chǎn)生
[Abstract]:In this paper, the antiferroelectric materials (Pb0.925-xLa0.05Bax) [Zr0.52 (SnyTiZ) 0.48] O3 (PLZST), in which the dielectric properties and charge-discharge life of PLZST ceramics were improved, were studied. The aim of this study was to improve the dielectric properties and the charge-discharge life of PLZST ceramic materials by replacing Pb partially with Ba and adjusting the Sn-Ti ratio. Then the material composition with high energy storage density is obtained. The effects of the composition of the materials on the microstructure, dielectric properties, energy storage density, energy storage efficiency and charge-discharge life were characterized by means of SEMX XRD, dielectric temperature tester, hysteretic loop tester and charge-discharge tester. In order to explore how the composition of the material affects the charge-discharge life, the high accelerated aging test (Halt), impedance spectroscopy, was used. Thermally stimulated depolarization current (TSDC) is used to detect the type of particles that cause aging and its role in the aging process. Ba doping inhibits the formation of pyrochlore phase in PLZST material and improves the stability of perovskite phase. When Ba increases from 0 to 10 mol%, the peak dielectric constant increases from 900 to 1200, and the peak temperature Tmax shifts from 145 鈩，

本文編號：2087447