王通, 王淵浩, 楊海波, 高淑雅, 王芬, 魯雅文

BaTiO3-ZnNb2O6陶瓷介電及儲(chǔ)能性能研究

王通1, 王淵浩1, 楊海波1, 高淑雅1, 王芬1, 魯雅文2

(1. 陜西科技大學(xué) 材料科學(xué)與工程學(xué)院, 陜西省無(wú)機(jī)材料綠色制備與功能化重點(diǎn)實(shí)驗(yàn)室, 西安 710021; 2. 咸陽(yáng)陶瓷研究設(shè)計(jì)院有限公司, 咸陽(yáng) 712000)

采用固相法制備(1–)BaTiO3-ZnNb2O6(=0.5mol%, 1mol%, 1.5mol%, 2mol%, 3mol%, 4mol%) (簡(jiǎn)稱(chēng)BTZN)陶瓷, 研究了BTZN陶瓷的燒結(jié)溫度、結(jié)構(gòu)、介電性能和鐵電性能。BTZN陶瓷燒結(jié)溫度隨著ZnNb2O6含量增加逐漸降低。XRD結(jié)果表明當(dāng)ZnNb2O6含量達(dá)到3mol%時(shí)出現(xiàn)第二相Ba2Ti5O12。介電測(cè)試結(jié)果表明隨ZnNb2O6含量的增加, BTZN陶瓷介電常數(shù)逐漸減小, 而介電常數(shù)的頻率穩(wěn)定性逐漸增強(qiáng)。介電溫譜表明所有BTZN陶瓷均符合X8R電容器標(biāo)準(zhǔn)。BTZN陶瓷的極化強(qiáng)度值隨著ZnNb2O6含量的增加逐漸降低。當(dāng)=4mol%時(shí), BTZN陶瓷獲得240 kV/cm的擊穿電場(chǎng)和1.22 J/cm3的可釋放能量密度。

鈦酸鋇; 陶瓷; 介電性能; 儲(chǔ)能性能

鈦酸鋇(BaTiO3)是一種典型的ABO3型鈣鈦礦結(jié)構(gòu)的鐵電體材料, 因其優(yōu)良的介電、壓電以及鐵電性能[1]被廣泛應(yīng)用于多層陶瓷電容器[2], 鐵電存儲(chǔ)器[3], 傳感器及非線(xiàn)性電光器件等[4-5]。BaTiO3(BT)陶瓷介電常數(shù)(r)非常高, 室溫為1500~2000 ℃, 在居里溫度(C)附近高達(dá)10000 ℃以上[6],r與溫度呈非線(xiàn)性關(guān)系, 導(dǎo)致r隨溫度變化率較大, 此外r對(duì)電場(chǎng)、頻率和壓力等條件變化也非常敏感。BT陶瓷介電損耗(tan>0.05)相對(duì)較高。BT陶瓷飽和極化強(qiáng)度值(s>27 μC/cm2)高[7], 而剩余極化強(qiáng)度值(r> 14.7 μC/cm2)也很高[8]。BT陶瓷擊穿電場(chǎng)(BDS< 100 kV/cm)較低[9]。

高r和大s使BT陶瓷成為一種非常有潛力的無(wú)鉛陶瓷儲(chǔ)能電容器材料[10-12], 可應(yīng)用于激光脈沖武器和混合電動(dòng)車(chē)等領(lǐng)域[13-19]。但高r和低BDS導(dǎo)致BT陶瓷儲(chǔ)能性能并不良好[20-22]。近年來(lái)許多研究人員嘗試在BT的A位和B位引入離子合成BT基弛豫鐵電體陶瓷從而降低r: Huang等[23]用Sol-Gel法合成Ba0.4Sr0.6TiO3陶瓷, 在240 kV/cm電場(chǎng)強(qiáng)度下獲得1.23 J/cm3能量存儲(chǔ)密度(), 和94.52%能量存儲(chǔ)效率()。Puli等[24]用固相法制備0.85Ba(Zr0.2Ti0.8)O3-0.15(Ba0.7Ca0.3)TiO3陶瓷, 在170 kV/cm下獲得0.94 J/cm3的和94.52 %的。Sun等[25]用固相法合成Ba1–xSm2x/3Zr0.15Ti0.85O3陶瓷,當(dāng)=0.003獲得1.15 J/cm3可釋放能量密度(rec)和92%的。此外, 在BT中加入Bi基化合物合成BT-Bi基弛豫鐵電體陶瓷成為近幾年研究熱點(diǎn): Wang等[26]用固相法合成(1–)BaTiO3-Bi(Mg2/3Nb1/3)O3陶瓷, 當(dāng)=0.1在143.5 kV/cm下獲得1.13 J/cm3的rec和92.4%的。Hu等[27]用固相法合成0.88BaTiO3- 0.12Bi(Mg1/2Ti1/2)O3陶瓷, 在224 kV/cm下獲得1.81 J/cm3的rec和88%的。Yuan等[28]用固相法合成0.9BaTiO3-0.1Bi(Zn0.5Zr0.5)O3陶瓷, 在264 kV/cm下獲得2.46 J/cm3的W和86.8%的。Li等[29]用固相法合成0.88BaTiO3-0.12Bi(Li0.5Nb0.5)O3陶瓷, 在270 kV/cm下獲得2.03 J/cm3的rec和88%的。上述BT基和BT-Bi基弛豫鐵電體陶瓷P均隨著離子化合物含量增加逐漸減小, 儲(chǔ)能性能得到明顯改善, 然而s急劇降低成為儲(chǔ)能性能提高的瓶頸。

為了提高BT基陶瓷BDS, 許多研究人員在BT基或BT-Bi基陶瓷中添加玻璃來(lái)提高致密度, 同時(shí)達(dá)到降低燒結(jié)溫度的效果。Wang等[30]在BT陶瓷中添加BaO-SrO-TiO2-Al2O3-SiO2-BaF2玻璃, 當(dāng)玻璃添加量為7wt%, BDS提高到94.6 kV/cm, 獲得0.32 J/cm3的rec。Wang等[31]在Ba0.4Sr0.6TiO3陶瓷中添加BaO-B2O3-SiO2-Na2CO3-K2CO3玻璃, BDS提高到280.5 kV/cm, 獲得0.72 J/cm3的rec。Yang等[32]在Ba0.4Sr0.6TiO3陶瓷中添加Bi2O3-B2O3-SiO2玻璃, 當(dāng)玻璃添加量為9wt%, BDS提高到279 kV/cm, 獲得1.98 J/cm3的rec和90.57%的。Yang等[33]在Ba0.85Ca0.15Zr0.1Ti0.9O3陶瓷中添加B2O3-Al2O3-SiO2玻璃, BDS提高到250 kV/cm, 當(dāng)玻璃添加量為5wt%, 獲得1.15 J/cm3的rec。Wu等[34]在Ba0.4Sr0.6Zr0.15Ti0.85O3陶瓷中添加SrO-B2O3-SiO2玻璃, BDS提高到220 kV/cm, 當(dāng)玻璃添加量為5wt%, 獲得0.45 J/cm3的rec和88.2%的。Wang等[35]在0.85BaTiO3-0.15Bi(Mg2/3Nb1/3)O3陶瓷中添加B2O3-Na2B4O7-Na2SiO3玻璃, BDS提高到240 kV/cm, 當(dāng)玻璃添加量為3wt%, 獲得1.26 J/cm3的rec和80.9%的。上述BT基和BT-Bi基玻璃陶瓷BDS均隨著玻璃含量增加而增大, 但同樣存在玻璃含量高時(shí)s大幅降低現(xiàn)象。此外在BT陶瓷中添加低溫晶相助燒劑也可改善BT基陶瓷BDS。鈮酸鋅(ZnNb2O6)[36]是一種典型低溫?zé)Y(jié)微波介質(zhì)陶瓷。Wang等[37]用固相法合成BaTiO3-ZnNb2O6(BT-ZN)陶瓷, 結(jié)果表明添加ZN顯著降低BT陶瓷燒結(jié)溫度。Yan等[38]和Yang等[39]分別用固相法和微波燒結(jié)法制備BT-ZN陶瓷, 結(jié)果表明添加ZN并未明顯改變BT陶瓷C。上述研究發(fā)現(xiàn)添加ZN使BT陶瓷BDS和儲(chǔ)能性能都得到改善, 但均未系統(tǒng)性研究ZnNb2O6含量對(duì)BT陶瓷介電常數(shù)頻率穩(wěn)定性和溫度穩(wěn)定性, 以及對(duì)極化強(qiáng)度值和儲(chǔ)能性能的影響。

本工作用固相法制備了BaTiO3-ZnNb2O6(BT-ZN)陶瓷, 系統(tǒng)地研究了ZnNb2O6含量對(duì)BT-ZN陶瓷燒結(jié)溫度、相結(jié)構(gòu)、顯微結(jié)構(gòu)、介電常數(shù)的頻率穩(wěn)定性和溫度穩(wěn)定性、擊穿電場(chǎng)、極化強(qiáng)度值和儲(chǔ)能性能的影響。

1 實(shí)驗(yàn)方法

1.1 樣品制備

以分析純BaCO3、TiO2、ZnO和Nb2O5為原料, 固相法制備(1–)BaTiO3-ZnNb2O6(=0.5mol%, 1mol%, 1.5mol%, 2mol%, 3mol%, 4mol%) (BTZN1-6)陶瓷。先分別稱(chēng)料BaCO3、TiO2、ZnO和Nb2O5,球磨6 h, 然后分別在1150和900 ℃煅燒2 h合成BT和ZN預(yù)燒粉, 并將預(yù)燒粉二次球磨。將BT和ZN預(yù)燒粉按配比稱(chēng)料球磨6 h, 干燥后加入PVA (5wt%)造粒, 在150 MPa下壓制成直徑12 mm, 厚度1~ 2 mm圓片生坯。600 ℃排膠4 h后在1100~ 1350 ℃下燒結(jié)2 h成瓷。用被銀法在850 ℃保溫20 min制備厚度1 mm的介電性能測(cè)試樣品。用噴金法制備厚度0.3 mm的鐵電性能測(cè)試樣品, 電極直徑為6 mm。

1.2 性能測(cè)試

采用阿基米德排水法測(cè)試樣品密度。采用Ｘ射線(xiàn)衍射儀(XRD, D8 Advance, Bruker, Germany)測(cè)試樣品相結(jié)構(gòu)。采用掃描電子顯微鏡(SEM, Verios 460, FEI, USA)觀察拋光熱腐蝕樣品表面顯微結(jié)構(gòu)。采用阻抗分析儀(E4990A, Aglient, USA)測(cè)試樣品介電性能頻率穩(wěn)定性, 頻率范圍為100 Hz~10 MHz。采用LCR電橋(E4980A, Aglient, USA)測(cè)試樣品介電性能溫度穩(wěn)定性, 溫度范圍為–100~500 ℃, 升溫速率3 ℃/min, 測(cè)試頻率為100 Hz、1 kHz、10 kHz、100 kHz和1 MHz。采用鐵電測(cè)試儀(Premier II, Radiant, USA)測(cè)試樣品室溫下電滯回線(xiàn), 測(cè)試頻率為10 Hz。

2 結(jié)果和討論

2.1 BTZN陶瓷的結(jié)構(gòu)分析

圖1是BTZN陶瓷不同燒結(jié)溫度的密度, 插圖為不同ZN含量BTZN陶瓷最佳燒結(jié)溫度和密度, BTZN陶瓷最佳燒結(jié)溫度隨ZN含量增加從1275 ℃ (BTZN1)降低到1200 ℃(BTZN6)。純BT陶瓷燒結(jié)溫度高達(dá)1375 ℃[3], 而ZN陶瓷燒結(jié)溫度僅有1150 ℃[36], 說(shuō)明添加ZN有效降低了BTZN陶瓷燒結(jié)溫度。而最佳燒結(jié)溫度下BTZN陶瓷密度隨ZN含量增加從5.808 g/cm3(BTZN1)降低到5.701 g/cm3(BTZN6), 主要由于ZN陶瓷的理論密度(5.645 g/cm3)比BT陶瓷(6.018 g/cm3)低[37]。

圖2(a)是BTZN陶瓷XRD圖譜, 結(jié)果表明所有樣品主晶相衍射峰為BaTiO3(No. 050626)。當(dāng)ZN含量達(dá)到3mol%時(shí)出現(xiàn)ZnNb2O6(No. 371371)和第二相Ba2Ti5O12(No. 170661)的衍射峰[37]。

圖2(b)是BTZN陶瓷31°到32°放大圖譜, 衍射峰隨ZN含量增加向低角度方向移動(dòng), 說(shuō)明晶面間距變大。通常容差因子在0.79~1.1可形成穩(wěn)定鈣鈦礦結(jié)構(gòu), 容差因子計(jì)算公式[40]:

式(1)中: rA——A位陽(yáng)離子半徑; rB——B位陽(yáng)離子半徑; rO——氧離子半徑。Zn2+取代A位和B位容差因子分別為0.728和0.909, 而Nb5+分別為0.718和0.926。Zn2+(0.074 nm)和Nb5+(0.070 nm)遠(yuǎn)小于A位Ba2+(0.135 nm), 比B位Ti4+(0.068 nm)略大。所以Zn2+和Nb5有可能取代B位Ti4+, 增大B–O八面體體積, 導(dǎo)致晶面間距增大。

圖2 (a)BTZN陶瓷XRD圖譜和(b)31°~32°放大圖譜

圖3是BTZN陶瓷的拋光熱腐蝕SEM照片, 從圖中可見(jiàn)所有樣品均很致密, 晶粒尺寸隨ZN含量增加顯著減小, 說(shuō)明ZN抑制BTZN陶瓷晶粒生長(zhǎng), 晶粒尺寸減小非常有利于提高陶瓷BDS[35]。

2.2 BTZN陶瓷的介電性能

圖4(a, b)是BTZN陶瓷介電常數(shù)(r)和介電損耗(tan)隨頻率變化的曲線(xiàn), BTZN陶瓷r和tan都隨ZN含量增加逐漸降低。100 Hz下r從3923 (BTZN1)降低到1604(BTZN6), tan從0.013(BTZN1)減小到0.006(BTZN6), 10 MHz下所有樣品tan<0.05, 這是由于ZN的r和tan都遠(yuǎn)遠(yuǎn)低于BT[36]。所有BTZN陶瓷r隨頻率升高逐漸降低, 是由于不同極化機(jī)制響應(yīng)頻率不同造成的。低頻下電子位移極化、離子位移極化和偶極子取向極化等各種機(jī)制都對(duì)r有貢獻(xiàn), 高頻時(shí)只有電子位移極化和離子位移極化機(jī)制[35]。BTZN1陶瓷r隨頻率升高降低較為明顯, 隨ZN含量增加, BTZN陶瓷r表現(xiàn)出良好的頻率穩(wěn)定性, 說(shuō)明ZN顯著減弱了BTZN陶瓷介電極化。

圖3 BTZN陶瓷熱腐蝕的SEM照片

(a) BTZN1; (b) BTZN2; (c) BTZN3; (d) BTZN4; (e) BTZN5; (f) BTZN6

圖4 BTZN陶瓷的介電性能頻率穩(wěn)定性

(a) Frequency dependence of dielectric constant (lines are linear fitting results) with inset showing the fitting values ofandwith different ZN content, and (b) frequency dependence of dielectric loss, (c), and (d)as a function of ZN content

為了進(jìn)一步研究ZN含量對(duì)BTZN陶瓷ε隨頻率變化的影響, 我們定義了一個(gè)公式:

式(2)中:r()——頻率為時(shí)的r;——測(cè)試頻率。圖4(a)中插圖是線(xiàn)性擬合斜率和截距的擬合值與ZN含量關(guān)系。隨ZN含量增加, 斜率從114.7(BTZN1)減小到26.6(BTZN6), 說(shuō)明r隨頻率變化率越來(lái)越小。截距和r減小規(guī)律一致, 從4195(BTZN1)減小到1670(BTZN6)。

我們通過(guò)定義頻率電容系數(shù)(Frequency coefficient of capacitance,)來(lái)描述BTZN陶瓷r頻率穩(wěn)定性:

式(3)中:100 Hz——頻率為100 Hz時(shí);C——頻率為時(shí)圖4(c)是隨頻率變化, 所有BTZN陶瓷均隨頻率升高逐漸減小, 是由于r隨頻率升高逐漸減小。為了進(jìn)一步描述ZN含量對(duì)影響, 圖4(d)是隨ZN含量變化曲線(xiàn), 在相同測(cè)試頻率下均隨ZN含量增加逐漸增大, 10 MHz下從–14.85%(BTZN1)提高到–8.45%(BTZN6), 說(shuō)明ZN添加有利于提高BTZN陶瓷r頻率穩(wěn)定性。

圖5是BTZN陶瓷在–100~500 ℃范圍內(nèi)的介電常數(shù)和介電損耗與溫度的關(guān)系。隨著ZN含量增加, BTZN陶瓷居里溫度(C)并沒(méi)有明顯變化, 而介電常數(shù)居里峰展寬較為明顯。Yang等[39]采用TEM在BTZN陶瓷晶粒和晶界處都發(fā)現(xiàn)了Zn和Nb元素, 說(shuō)明ZnNb2O6和BaTiO3形成了固溶體。但晶界處Zn和Nb元素含量明顯高于晶粒內(nèi)部, 且觀察到BTZN陶瓷存在殼核結(jié)構(gòu)。由于殼核結(jié)構(gòu)的形成和Zn2+和Nb5+取代B位Ti4+造成BTZN陶瓷的化學(xué)成分不均勻, 引起彌散相變導(dǎo)致居里峰展寬[38]。C處最大介電常數(shù)(m)隨ZN含量增加逐漸減小, 1 MHz下m從3956(BTZN1)降低到1694(BTZN6), 主要是由于ZN的r低于BT[36]。C和m的變化和其他在BT中添加ZN的文獻(xiàn)報(bào)道結(jié)果一致[38-39]。用電容溫度系數(shù)(Temperature Coefficient of Capacitance,)來(lái)進(jìn)一步研究BTZN陶瓷r的溫度穩(wěn)定性[35, 41-42]:

式(4)中:25℃——25 ℃時(shí)的電容;T——溫度時(shí)的電容。

圖6是BTZN陶瓷基于25 ℃在1 MHz下的, 虛線(xiàn)表示范圍是±15%, 25 ℃的為0, 位于兩條虛線(xiàn)中間。從圖中可以看出, 所有BTZN陶瓷均滿(mǎn)足X8R(–55~150 ℃, ΔC/25℃≤±15%)[43]電容器標(biāo)準(zhǔn)。

2.3 BTZN陶瓷的儲(chǔ)能性能

圖7是BTZN陶瓷擊穿電場(chǎng)下的室溫電滯回線(xiàn)(10 Hz)。所有樣品表現(xiàn)出瘦電滯回線(xiàn), 高BDS, 大s和低r, 適合應(yīng)用于能量存儲(chǔ)領(lǐng)域[26]。插圖是不同ZN含量的BTZN陶瓷的BDS, BDS隨ZN含量增加而增大。從80 kV/cm(BTZN1)增大到240 kV/cm(BTZN6), BDS的提高主要是由于晶粒尺寸減小(圖3)。

圖8(a)是不同ZN含量BTZN陶瓷在100 kV/cm下(最大極化強(qiáng)度值)的max、r和max-r(BTZN1陶瓷的BDS為80 kV/cm, 所以并未出現(xiàn))。max、r和max-r均隨著ZN含量增加逐漸減小。max和r分別從20.26和4.48 μC/cm2(BTZN2)減小到11.67和1.37 μC/cm2(BTZN6), 這是由于添加ZN稀釋了BTZN陶瓷的鐵電性, 和其他BT-ZN陶瓷的結(jié)果一致[37-39]。用-曲線(xiàn)研究BTZN陶瓷儲(chǔ)能性能, 曲線(xiàn)由于存在滯回, 充電曲線(xiàn)和放電曲線(xiàn)并不重合。能量存儲(chǔ)密度()是充電電流曲線(xiàn)和極化強(qiáng)度軸包圍的面積積分, 可釋放能量密度(rec)是放電電流曲線(xiàn)和極化強(qiáng)度軸包圍的面積積分, 損失掉能量密度(loss)是充放電電流曲線(xiàn)包圍的面積積分, 能量存儲(chǔ)效率()是rec/。因此,rec,loss和都是衡量能量存儲(chǔ)性能的重要指標(biāo)[35]:

圖5 BTZN陶瓷–100~500 ℃的介電常數(shù)和介電損耗

(a) BTZN1; (b) BTZN2; (c) BTZN3; (d) BTZN4; (e) BTZN5; (f) BTZN6

圖6 BTZN陶瓷1 MHz下基于25 ℃的TCC

圖7 BTZN陶瓷擊穿電場(chǎng)下室溫電滯回線(xiàn)(10 Hz), 箭頭方向?yàn)閆N含量增大方向, 插圖為不同ZN含量BTZN陶瓷BDS

max,randmax-rof BTZN ceramics at 100 kV/cm; (b) Energy storage density (); (c) Recoverable energy storage density (rec); (d) Energy loss density (loss); (e) Energy storage efficiency () as a function of electric field; (f) Variations of,rec,lossandat critical electric field with different ZN contents

式(5~8)中:——電場(chǎng)強(qiáng)度;——極化強(qiáng)度值。

圖8(b)~(e)是BTZN陶瓷不同電場(chǎng)強(qiáng)度下,rec,loss和。隨ZN含量增加,rec和loss都逐漸增加, 而逐漸減小, 主要由于loss隨電場(chǎng)強(qiáng)度增加顯著增大[26, 35]。實(shí)際應(yīng)用不僅需要高rec, 同時(shí)高也是必須的, 低材料在充放電過(guò)程中會(huì)將大量電能轉(zhuǎn)換成熱能, 導(dǎo)致材料性能惡化[35]。當(dāng)ZN的含量為4mol%時(shí), 不同電場(chǎng)下均高于77.6%。圖8(f)是不同ZN含量BTZN陶瓷在各自BDS下的,rec,loss和, 隨ZN含量增加,rec,loss和大體呈增大趨勢(shì), 當(dāng)ZN含量4mol%, BTZN6陶瓷在240 kV/cm電場(chǎng)下獲得1.22 J/cm3的rec和77.6%的。

3 結(jié)論

本研究采用固相法制備(1–)BaTiO3-ZnNb2O6(=0.5mol%, 1mol%, 1.5mol%, 2mol%, 3mol%, 4mol%)陶瓷。添加ZN有效降低了BTZN陶瓷的最佳燒結(jié)溫度。XRD結(jié)果表明所有樣品主晶相為BaTiO3, 當(dāng)ZN含量達(dá)到3mol%時(shí)出現(xiàn)ZnNb2O6和第二相Ba2Ti5O12。BTZN陶瓷晶粒尺寸隨ZN含量增加顯著減小。r和tan隨ZN含量增加逐漸降低, 100 Hz下r從3923降低到1604, tan從0.013減小到0.006, 10 MHz下所有樣品tan<0.05。r頻率穩(wěn)定性隨ZN含量增加逐漸增強(qiáng), 10 MHz下從–14.85%提高到–8.45%。介電溫譜結(jié)果表明所有BTZN陶瓷均符合X8R電容器標(biāo)準(zhǔn)。BDS隨ZN含量增加而增大, 從80 kV/cm增大到240 kV/cm。極化強(qiáng)度值隨著ZN含量的增加逐漸降低, 100 kV/cm下max和r分別從20.26和4.48 μC/cm2減小到11.67和1.37 μC/cm2。隨ZN含量增加,rec,loss和大體上呈增大趨勢(shì), 當(dāng)ZN含量為4mol%時(shí), BTZN6陶瓷在240 kV/cm電場(chǎng)下獲得1.22 J/cm3的rec和77.6%的。結(jié)果表明BTZN陶瓷有望應(yīng)用于高溫電容器和儲(chǔ)能領(lǐng)域。

[1] ACOSTA M, NOVAK N, ROJAS V,BaTiO3-based piezoelectrics: fundamentals, current status, and perspectives., 2017, 4(4): 041305.

[2] HENNINGS D, ROSENSTEIN G. Temperature-stable dielectrics based on chemically inhomogeneous BaTiO3., 1984, 67(4): 249–254.

[3] JIANG X W, HAO H, ZHANG S J,Enhanced energy storage and fast discharge properties of BaTiO3based ceramics modified by Bi(Mg1/2Zr1/2)O3., 2019, 39(4): 1103–1109.

[4] HUANG Y A, LU B, YI X Z,Grain size effect on dielectric, piezoelectric and ferroelectric property of BaTiO3ceramics with fine grains., 2018, 33(7): 767–772.

[5] GHAYOUR H, ABDELLAHI M. A brief review of the effect of grain size variation on the electrical properties of BaTiO3-based ceramics., 2016, 292: 84–93.

[6] ZEB A, MILNE S J. Temperature-stable dielectric properties from ?20 ℃ to 430 ℃ in the system BaTiO3-Bi(Mg0.5Zr0.5)O3., 2014, 34(13): 3159–3166.

[7] DAMJANOVIC D. Ferroelectric, dielectric and piezoelectric properties of ferroelectric thin films and ceramics., 1998, 61(9): 1267–1324.

[8] GUO F Q, ZHANG B H, FAN Z X,Grain size effects on piezoelectric properties of BaTiO3ceramics prepared by spark plasma sintering., 2016, 27(6): 5967–5971.

[9] YUAN Q B, LI G, YAO F Z,Simultaneously achieved temperature- insensitive high energy density and efficiency in domain engineered BaTiO3-Bi(Mg0.5Zr0.5)O3lead-free relaxor ferroelectrics., 2018, 52: 203–210.

[10] HAO X H. A review on the dielectric materials for high energy- storage application., 2013, 03(1): 1330001.

[11] DU H L, YANG Z T, GAO F,Lead-free nonlinear dielectric ceramics for energy storage applications: current status and challenges., 2018, 33(10): 1046–1058.

[12] YANG L T, KONG X, LI F,Perovskite lead–free dielectrics for energy storage applications., 2019, 102: 72–108.

[13] YAN F, YANG H B, LIN Y,Dielectric and ferroelectric properties of SrTiO3-Bi0.5Na0.5TiO3-BaAl0.5Nb0.5O3lead-free ceramics for high-energy-storage applications., 2017, 56(21): 13510–13516.

[14] YANG H B, YAN F, LIN Y,Novel strontium titanate-based lead-free ceramics for high-energy storage applications., 2017, 5(11): 10215–10222.

[15] YANG H B, YAN F, LIN Y,Lead-free BaTiO3- Bi0.5Na0.5TiO3-Na0.73Bi0.09NbO3relaxor ferroelectric ceramics for high energy storage., 2017, 37(10): 3303–3311.

[16] YAN F, YANG H B, YING L,Enhanced energy storage properties of a novel lead-free ceramic with a multilayer structure., 2018, 6(29): 7905–7912.

[17] LIU X Y, YANG H B, YAN F,Enhanced energy storage properties of BaTiO3-Bi0.5Na0.5TiO3lead-free ceramics modified by SrY0.5Nb0.5O3., 2019, 778: 97–104.

[18] YANG H B, LIU P F, YAN F,A novel lead-free ceramic with layered structure for high energy storage applications., 2019, 773: 244–249.

[19] YANG Z T, GAO F, DU H L,Grain size engineered lead-free ceramics with both large energy storage density and ultrahigh mechanical properties., 2019, 58: 768–777.

[20] WANG T, JIN L, TIAN Y,Microstructure and ferroelectric properties of Nb2O5-modified BiFeO3-BaTiO3lead-free ceramics for energy storage., 2014, 137: 79–81.

[21] JIN L, LI F, ZHANG S J. Decoding the fingerprint of ferroelectric loops: comprehension of the material properties and structures., 2014, 97(1): 1–27.

[22] WANG T, HU J C, YANG H B,Dielectric relaxation and Maxwell-Wagner interface polarization in Nb2O5doped 0.65BiFeO3-0.35BaTiO3ceramics., 2017, 121(8): 084103.

[23] HUANG Y H, WU Y J, LI J,Enhanced energy storage properties of barium strontium titanate ceramics prepared by Sol-Gel method and spark plasma sintering., 2017, 701: 439–446.

[24] PULI V S, PRADHAN D K, CHRISEY D B,Structure, dielectric, ferroelectric, and energy density properties of (1?)BZT–BCT ceramic capacitors for energy storage applications., 2012, 48(5): 2151–2157.

[25] SUN Z, LI L X, YU S H,Energy storage properties and relaxor behavior of lead-free Ba1-xSm2x/3Zr0.15Ti0.85O3ceramics., 2017, 46(41): 14341–14347.

[26] WANG T, JIN L, LI C C,Relaxor ferroelectric BaTiO3- Bi(Mg2/3Nb1/3)O3ceramics for energy storage application., 2015, 98(2): 559–566.

[27] HU Q Y, JIN L, WANG T,Dielectric and temperature stable energy storage properties of 0.88BaTiO3-0.12Bi(Mg1/2Ti1/2)O3bulk ceramics., 2015, 640: 416–420.

[28] YUAN Q B, YAO F Z, WANG Y F,Relaxor ferroelectric 0.9BaTiO3-0.1Bi(Zn0.5Zr0.5)O3ceramic capacitors with high energy density and temperature stable energy storage properties., 2017, 5(37): 9552–9558.

[29] LI W B, ZHOU D, PANG L X,Novel barium titanate based capacitors with high energy density and fast discharge performance., 2017, 5(37): 19607–19612.

[30] WANG X R, ZHANG Y, SONG X Z,Glass additive in barium titanate ceramics and its influence on electrical breakdown strength in relation with energy storage properties., 2012, 32(3): 559–567.

[31] WANG T, JIN L, SHU L L,Energy storage properties in Ba0.4Sr0.6TiO3ceramics with addition of semi-conductive BaO-B2O3-SiO2-Na2CO3-K2CO3glass., 2014, 617: 399–403.

[32] YANG H B, YAN F, LIN Y,Enhanced energy storage properties of Ba0.4Sr0.6TiO3lead-free ceramics with Bi2O3-B2O3-SiO2glass addition., 2018, 38(4): 1367–1373.

[33] YANG H B, YAN F, ZHANG G,Dielectric behavior and im-pedance spectroscopy of lead-free Ba0.85Ca0.15Zr0.1Ti0.9O3ceramics with B2O3-Al2O3-SiO2glass-ceramics addition for enhanced energy storage., 2017, 720: 116–125.

[34] WU T, PU Y P, CHEN K. Dielectric relaxation behavior and energy storage properties in Ba0.4Sr0.6Zr0.15Ti0.85O3ceramics with glass additives., 2013, 39(6): 6787–6793.

[35] WANG T, WANG Y H, YANG H B,Structure, dielectric properties of low-temperature-sintering BaTiO3-based glass-ce-ramics for energy storage., 2018, 8(6): 1850041.

[36] GAO F, LIU J J, HONG R Z,Microstructure and dielectric properties of low temperature sintered ZnNb2O6microwave ceramics., 2009, 35(7): 2687–2692.

[37] WANG T, WEI X Y, HU Q Y,Effects of ZnNb2O6addition on BaTiO3ceramics for energy storage., 2013, 178(16): 1081–1086.

[38] YAN Y, NING C, JIN Z Z,The dielectric properties and microstructure of BaTiO3ceramics with ZnO-Nb2O5composite addition., 2015, 646: 748–752.

[39] YANG Y, LIU K H, LIU X K,Electrical properties and microstructures of (Zn and Nb) co-doped BaTiO3ceramics prepared by microwave sintering., 2016, 42(6): 7877–7882.

[40] SPAGNOL P D, VARELA J A, ZAGHETE M A,Evidence of hetero-epitaxial growth of Pb(Mg1/3Nb2/3)O3on the BaTiO3seed particles of a citrate solution., 2002, 77(3): 918–923.

[41] YANG H B, YAN F, LIN Y,Enhanced energy-storage properties of lanthanum-doped Bi0.5Na0.5TiO3-based lead-free ceramics., 2018, 6(2): 357–365.

[42] JIA W X, HOU Y D, ZHENG M P,Superior temperature- stable dielectrics for MLCCs based on Bi0.5Na0.5TiO3-NaNbO3system modified by CaZrO3., 2018, 101(8): 3468–3479.

[43] SUN Y, LIU H, HAO H,Structure property relationship in BaTiO3-Na0.5Bi0.5TiO3-Nb2O5-NiO X8R system., 2015, 98(5): 1574–1579.

Dielectric and Energy Storage Property of BaTiO3-ZnNb2O6Ceramics

WANG Tong1, WANG Yuanhao1, YANG Haibo1, GAO Shuya1, WANG Fen1, LU Yawen2

1. Shaanxi Key Laboratory of Green Preparation and Functionalization for Inorganic Materials, School of Materials Science and Engineering, Shaanxi University of Science & Technology, Xi’an 710021, China; 2. Xianyang Research and Design Institute of Ceramics Co. Ltd, Xianyang 712000, China)

(1–)BaTiO3-ZnNb2O6(=0.5mol%, 1mol%, 1.5mol%, 2mol%, 3mol%, 4mol%) (BTZN) ceramics were synthesized by solid state method. The sintering temperature, structure, dielectric property and ferroelectric property of BTZN ceramics were systematically investigated. The sintering temperature of BTZN ceramics decreased with increasing ZnNb2O6content. XRD results show that the second phase Ba2Ti5O12was observed when the content of ZnNb2O6reached 3mol%. The dielectric measurements result showed that with increasing ZnNb2O6content, the dielectric constant of BTZN ceramics decreased gradually, while the frequency stability of dielectric constant increasedgradually. The temperature dependence of dielectric constant results showed that all BTZN ceramics met the characteristics of X8R capacitors.Polarization values of BTZN ceramics decreased with increasing ZnNb2O6content. The dielectric breakdown strength of 240 kV/cm and arecoverable energy density of 1.22 J/cm3were achieved in the sample of=4mol%.

BaTiO3; ceramics; dielectric property; energy storage property

TQ174

A

1000-324X(2020)04-0431-08

10.15541/jim20190170

2019-04-22;

2019-06-12

國(guó)家自然科學(xué)基金(51702196); 中國(guó)博士后科學(xué)基金(2017M620435); 陜西省自然科學(xué)基礎(chǔ)研究計(jì)劃(2017JQ5088); 陜西省教育廳專(zhuān)項(xiàng)科研計(jì)劃(17JK0105); 陜西科技大學(xué)博士科研啟動(dòng)基金(BJ16-07)

National Natural Science Foundation of China (51702196); China Postdoctoral Science Foundation (2017M620435); Natural Science Foundation of Shaanxi Province (2017JQ5088); Scientific Research Program Funded by Shaanxi Provincial Education Department (17JK0105); Research Starting Foundation of Shaanxi University of Science and Technology (BJ16-07)

王通(1985–), 男, 講師. E-mail: andyton85@163.com

WANG Tong(1985–), male, lecturer. E-mail: andyton85@163.com

楊海波, 教授. E-mail: yanghaibo@sust.edu.cn

YANG Haibo, professor. E-mail: yanghaibo@sust.edu.cn