Novel Strontium Titanate-Based Lead-Free Ceramics for High-Energy

Sep 27, 2017 - Origin of composition-insensitive electrostrictive coefficient and continuous decrease of domain wall density in (1- x )NaNbO 3 - x BaT...
1 downloads 4 Views 7MB Size
Download PDF
Research Article pubs.acs.org/journal/ascecg

Cite This: ACS Sustainable Chem. Eng. 2017, 5, 10215-10222

Novel Strontium Titanate-Based Lead-Free Ceramics for High-Energy Storage Applications Haibo Yang,* Fei Yan, Ying Lin, and Tong Wang School of Materials Science and Engineering, Shaanxi University of Science and Technology, 710021, Weiyang District, Xi’an, China ABSTRACT: To achieve the miniaturization and integration of advanced pulsed power capacitors, it is highly desirable to develop lead-free ceramic materials with high recoverable energy density (Wrec) and high energy storage efficiency (η). Whereas, Wrec (2 J/cm3) and high η (>80%), simultaneously, because of large Pr and low BDS.19,20 For instance, Shen et al. reported that a Wrec of 0.71 J/cm3 and a η of 71.5% could be obtained at 93 kV/cm in 0.91BaTiO30.09BiYbO 3 ceramic. 21 Xu et al. obtained the 0.90(0.92Bi0.5Na0.5TiO3-0.08BaTiO3)-0.10NaTaO3 ceramic with a Wrec of 1.2 J/cm3 and a η of 74.8% at 100 kV/cm.22 Recently, Wang et al. reported that the [(Bi 0.5 Na 0.5 ) 0.94 Ba 0.06 ]La(1−x)ZrxTiO3 ceramics have double P−E hysteresis loops, small Pr, and large Pmax (37.5 μC/cm2), but the BDS is too low to obtain high energy storage properties (the maximum value of Wrec is only 1.58 J/cm3).23 KNN-based ceramics are more beneficial to be used for advanced pulsed power capacitors due to high Wrec (∼4 J/cm3), but their value of η are lower than 65% because of larger Pr. A Wrec of 4.03 J/cm3 and a η of 52% were achieved for 0.85(K0.5Na0.5)NbO3-0.15SrTiO3 ceramic.24 Dielectric materials with lower η lose a higher amount of their stored energy to heat, and the generated heat would degrade the properties of dielectric materials.25 Meanwhile, the cost of raw materials for KNN-based ceramics is too expensive to be commercialized, and it is difficult to obtain KNN-based ceramics because the sintering temperature range of KNN ceramics is extremely narrow.26−28 Therefore, for lead-free energy storage ceramic materials not only the excellent properties but also the cost and feasible mass-production

fabrication process should also been considered. SrTiO3 (ST) needs relatively inexpensive raw materials, has a broad sintering temperature range, and can be used for mass-production for high-voltage capacitors.29 In addition, ST-based ceramics are also expected to be used for high energy storage capacitors. Because ST possesses unique physical properties, for instance, low dielectric loss ( 80%. Therefore, the (1−x)ST-x(BNTBLZT) (x = 0−0.5) ceramics can be used for high energy storage applications.

■

EXPERIMENTAL SECTION

Materials Preparation. The (1−x)ST-x(BNT-BLZT) (x = 0.0− 0.5) lead-free ceramics were fabricated using the tape-casting process and sintered by solid-state sintering method. First, ST and BNT-BLZT powders were synthesized, respectively. SrCO3 (>99.0%) and TiO2 10216

DOI: 10.1021/acssuschemeng.7b02203 ACS Sustainable Chem. Eng. 2017, 5, 10215−10222

Research Article

ACS Sustainable Chemistry & Engineering (>99.8%) were weighed by the nominal composition of ST and ball milled in alcohol for 12 h. The obtained powders were dried and calcined at 1150 °C for 4 h in air, and then milled again in alcohol for 12 h. Bi2O3 (>99%), Na2CO3 (>99.8%), TiO2 (>99.8%), BaCO3 (>99.0%), La2O3 (>99.9%), and ZrO2 (>99%) were the raw materials of BNT-BLZT powders. The preparation process was as same as that of ST powders, except that BNT-BLZT powders were calcined at 800 °C for 4 h. BNT-BLZT and ST powders were mixed according to the composition of (1−x)ST-x(BNT-BLZT) and ball-milled in alcohol for 12 h. After drying, the (1−x)ST-x(BNT-BLZT) mixture powders can be obtained. To get the slurries, dispersant (glycerol trioleate) and solvent (alcohol and butanone) were milled for 4 h. Then some plasticizer (dibutyl phthalate), binder (polyvinyl butyral and polyethylene glycol), and (1−x)ST-x(BNT-BLZT) powders were added and milled for 4 h again. Finally, the obtained slurries were casted on Mylar substrates. The schematic drawing of the fabrication process are shown in Figure 2. The ceramic membrane was laminated first and uniaxially pressed under 120 MPa at room temperature. And then, heating at 80 °C and pressing under 200 MPa again. Finally, binders were removed at 550 °C for 24 h, and all the samples were sintered at 1300−1350 °C for 2 h. To prevent the loss of volatile Bi3+ and Na+, the samples were embedded in the corresponding powders during sintering. Characterization. The X-ray diffractometer (XRD, D-MAX 2200pc, Rigaku Co., Tokyo, Japan) was used to detect phase structure of (1−x)ST-x(BNT-BLZT) ceramics. The microstructure of (1− x)ST-x(BNT-BLZT) ceramics was observed by a scanning electron microscopy (SEM, S4800, Rigaku Co., Japan). The frequency dependent dielectric properties were measured by an impedance analyzer (E4990A, Agilent, Palo Alto, CA). The temperaturedependent dielectric properties were measured using an LCR meter (3532-50, Hioki, Ueda, Japan) at a frequency of 1 kHz. The P−E loops were measured by a ferroelectric test system (Premier II, Radiant, USA) and the samples with a thickness of 0.20 mm.

Figure 4. SEM of (1−x)ST-x(BNT-BLZT) ceramics: (a) x = 0; (b) x = 0.1; (c) x = 0.2; (d) x = 0.3; (e) x = 0.4; and (f) x = 0.5.

Measurer), as shown in Figure 5a−f. It can be found that the average grain size increases from 1.09 to 4.86 μm with increasing BNT-BLZT content. The increase of grain size might be the result of the A-site elements (Bi3+ and Na+) volatilizing inevitably because of their low melting points,22,38 leading to the presence of oxygen vacancies and promoting mass transportation during sintering.39 Figure 6 shows the frequency dependent dielectric constant (ε′) and dielectric loss (tan δ) for (1−x)ST-x(BNT-BLZT) ceramics. It can be found that the ε′ almost remains a constant with measurement frequency when x ≤ 0.4, and then an excellent frequency stability of ε′ can be observed. In addition, the ε′ of (1−x)ST-x(BNT-BLZT) ceramics increases with increasing BNT-BLZT content gradually. It is because, compared with ST, BNT-BLZT has larger ε′ and higher Curie temperature (TC).23,40 Meanwhile, all the samples keep a low value of tan δ ( 80%.

Figure 12. (a) Unipolar P−E loops of 0.8ST-0.2(BNT-BLZT) ceramics with different electric fields at room temperature. (b) Calculated W and Wrec from panel a. (c) Calculated Wloss and η from panel a.

■

CONCLUSIONS In this study, novel ST-BNT-BLZT lead-free ceramics were successfully fabricated by the tape-casting process and sintered via solid-state sintering method for achieving large Pmax, high BDS, high Wrec, and high η. All the samples have slim P−E loops. The Pmax gradually increases and reaches the maximum value of 28.44 μC/cm2 for the sample with x = 0.5 at 160 kV/ cm, which is 4.44 times as large as that of pure ST (6.40 μC/ cm2). A high Wrec (2.83 J/cm3) and high η (85%) can be

Figure 13. A comparison of η and Wrec between (1−x)ST-x(BNTBLZT) ceramics and other lead-free ceramics.

simultaneously achieved for 0.8ST-0.2(BNT-BLZT) ceramic at 320 kV/cm. The significantly enhanced Wrec (2.83 J/cm3) is almost 2 times higher than previous reported results of lead-free ceramics with η > 80%, which indicates that the (1−x)ST10220

DOI: 10.1021/acssuschemeng.7b02203 ACS Sustainable Chem. Eng. 2017, 5, 10215−10222

Research Article

ACS Sustainable Chemistry & Engineering

(Zr0.68Sn0.24Ti0.08)O3 anti-ferroelectric ceramics fabricated by the hotpress sintering method. J. Eur. Ceram. Soc. 2013, 33, 113−121. (13) Zhang, L.; Jiang, S.; Zeng, Y.; Fu, M.; Han, K.; Li, Q.; Wang, Q.; Zhang, G. Y doping and grain size co-effects on the electrical energy storage performance of (Pb0.87Ba0.1La0.02)(Zr0.65Sn0.3Ti0.05)O3 antiferroelectric ceramics. Ceram. Int. 2014, 40, 5455−5460. (14) Xu, L.; He, C.; Yang, X.; Wang, Z.; Li, X.; Tailor, H. N.; Long, X. Composition dependent structure, dielectric and energy storage properties of Pb(Tm1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3 antiferroelectric ceramics. J. Eur. Ceram. Soc. 2017, 37, 3329−3334. (15) Rödel, J.; Jo, W.; Seifert, K.; Anton, E.; Granzow, T.; Damjanovic, D. Perspective on the development of lead-free piezoceramics. J. Am. Ceram. Soc. 2009, 92, 1153−1177. (16) Wang, T.; Jin, L.; Li, C.; Hu, Q.; Wei, X. Relaxor ferroelectric BaTiO3-Bi(Mg2/3Nb1/3)O3 ceramics for energy storage application. J. Am. Ceram. Soc. 2015, 98, 559−566. (17) Yao, M.; Pu, Y.; Zhang, L.; Chen, M. Enhanced energy storage properties of (1-x)Bi0.5Na0.5TiO3-xBa0.85Ca0.15Ti0.9Zr0.1O3 ceramics. Mater. Lett. 2016, 174, 110−113. (18) Chao, S.; Dogan, F. BaTiO3-SrTiO3 layered dielectrics for energy storage. Mater. Lett. 2011, 65, 978−981. (19) Yang, H.; Yan, F.; Zhang, G.; Lin, Y.; Wang, F. Dielectric behavior and impedance spectroscopy of lead-free Ba0.85Ca0.15Zr0.1Ti0.9O3 ceramics with B2O3-Al2O3-SiO2 glass-ceramics addition for enhanced energy storage. J. Alloys Compd. 2017, 720, 116−125. (20) Xu, Q.; Xie, J.; He, Z.; Zhang, L.; Cao, M.; Huang, X.; Lanagan, M.; Hao, H.; Yao, Z.; Liu, H. Energy-storage properties of Bi0.5Na0.5TiO3-BaTiO3-KNbO3 ceramics fabricated by wet-chemical method. J. Eur. Ceram. Soc. 2017, 37, 99−106. (21) Shen, Z.; Wang, X.; Luo, B.; Li, L. BaTiO3-BiYbO3 perovskite materials for energy storage applications. J. Mater. Chem. A 2015, 3, 18146−18153. (22) Xu, Q.; Liu, H.; Zhang, L.; Xie, J.; Hao, H.; Cao, M.; Yao, Z.; Lanagan, M. Structure and electrical properties of lead-free Bi0.5Na0.5TiO3-based ceramics for energy-storage applications. RSC Adv. 2016, 6, 59280−59291. (23) Wang, Y.; Lv, Z.; Xie, H.; Cao, J. High energy-storage properties of [(Bi1/2Na1/2)0.94 Ba0.06]La(1‑x)ZrxTiO3 lead-free anti-ferroelectric ceramics. Ceram. Int. 2014, 40, 4323−4326. (24) Yang, Z.; Du, H.; Qu, S.; Hou, Y.; Ma, H.; Wang, J.; Wang, J.; Wei, X.; Xu, Z. Significantly enhanced recoverable energy storage density in potassium-sodium niobate-based lead free ceramics. J. Mater. Chem. A 2016, 4, 13778−13785. (25) Jo, H. R.; Lynch, C. S. A high energy density relaxor antiferroelectric pulsed capacitor dielectric. J. Appl. Phys. 2016, 119, 024104. (26) Wang, K.; Li, J. (K, Na)NbO3-based lead-free piezoceramics: Phase transition, sintering and property enhancement. J. Adv. Ceram. 2012, 1, 24−37. (27) Ibn-Mohammed, T.; Koh, S.; Reaney, I.; Sinclair, D.; Mustapha, K.; Acquaye, A.; Wang, D. Are lead-free piezoelectrics more environmentally friendly? MRS Commun. 2017, 7, 1−7. (28) Malič, B.; Koruza, J.; Hrešcǎ k, J.; Bernard, J.; Wang, K.; Fisher, J.; Benčan, A. Sintering of lead-free piezoelectric sodium potassium niobate ceramics. Materials 2015, 8, 8117−8146. (29) Xiong, Z.; Zhou, X.; Zen, W.; Baba-Kishi, K.; Chen, S. Development of ferroelectric ceramics with high dielectric constant and low dissipation factor for high-voltage capacitors. J. Electroceram. 1999, 3, 239−244. (30) Wang, Z.; Cao, M.; Yao, Z.; Song, Z.; Li, G.; Hu, W.; Hao, H.; Liu, H. Dielectric relaxation behavior and energy storage properties in SrTiO3 ceramics with trace amounts of ZrO2 additives. Ceram. Int. 2014, 40, 14127−14132. (31) Zhang, G.; Liu, H.; Yao, Z.; Cao, M.; Hao, H. Effects of Ca doping on the energy storage properties of (Sr, Ca)TiO3 paraelectric ceramics. J. Mater. Sci.: Mater. Electron. 2015, 26, 2726−2732. (32) Song, Z.; Zhang, S.; Liu, H.; Hao, H.; Cao, M.; Li, Q.; Wang, Q.; Yao, Z.; Wang, Z.; Lanagan, M. Improved energy storage properties

x(BNT-BLZT) ceramics can be considered as potential candidate ceramic capacitors for high energy storage applications. In addition, the finding in this study could push the development of ST-based ceramics with enhanced Pmax, high Wrec, and high η in the future.

■

AUTHOR INFORMATION

Corresponding Author

*E-mail: [email protected]. ORCID

Haibo Yang: 0000-0003-1828-3750 Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS This work is supported by the National Natural Science Foundation of China (Grant No. 51572159, 51702196), the Chinese Postdoctoral Science Foundation (Grant No. 2016M590916), the Science and Technology Foundation of Weiyang District of Xi’an City (Grant No. 201605), the Industrialization Foundation of Education Department of Shaanxi Provincial Government (Grant No. 16JF002).

■

REFERENCES

(1) Dang, Z. M.; Yuan, J. K.; Zha, J. W.; Zhou, T.; Li, S. T.; Hu, G. H. Fundamentals, processes and applications of high-permittivity polymer-matrix composites. Prog. Mater. Sci. 2012, 57, 660−723. (2) Zhao, Y.; Hao, X.; Zhang, Q. Energy-storage properties and electrocaloric effect of Pb(1−3x/2)LaxZr0.85Ti0.15O3 Antiferroelectric Thick Films. ACS Appl. Mater. Interfaces 2014, 6, 11633−11639. (3) Park, M. H.; Kim, H. J.; Kim, Y. J.; Moon, T.; Kim, K. D.; Hwang, C. S. Thin HfxZr1‑xO2 films: A new lead-free system for electrostatic supercapacitors with large energy storage density and robust thermal stability. Adv. Energy Mater. 2014, 4, 1400610. (4) Chu, B. J.; Zhou, X.; Ren, K. L.; Neese, B.; Li, M. R.; Wang, Q.; Bauer, F.; Zhang, Q. M. A dielectric polymer with high electric energy density and fast discharge speed. Science 2006, 313, 334−336. (5) Khanchaitit, P.; Han, K.; Gadinski, M. R.; Li, Q.; Wang, Q. Ferroelectric polymer networks with high energy density and improved discharged efficiency for dielectric energy storage. Nat. Commun. 2013, 4, 1−7. (6) Hao, X. A review on the dielectric materials for high energystorage application. J. Adv. Dielectr. 2013, 03, 1330001. (7) Yao, K.; Chen, S.; Rahimabady, M.; Mirshekarloo, M. S.; Yu, S.; Tay, F.; Sritharan, T.; Lu, L. Nonlinear dielectric thin films for high power electric storage with energy density comparable with electrochemical supercapacitors. IEEE Trans. Ultrason. Ferr. 2011, 58, 1968− 1974. (8) Qu, B.; Du, H.; Yang, Z. Lead free relaxor ferroelectric ceramics with high optical transparency and energy storage ability. J. Mater. Chem. C 2016, 4, 1795−1803. (9) Yang, H.; Yan, F.; Lin, Y.; Wang, T.; Wang, F.; Wang, Y.; Guo, L.; Tai, W.; Wei, H. Lead-free BaTiO3-Bi0.5Na0.5TiO3-Na0.73Bi0.09NbO3 relaxor ferroelectric ceramics for high energy storage. J. Eur. Ceram. Soc. 2017, 37, 3303−3311. (10) Liu, G.; Fan, H.; Dong, G.; Shi, J.; Chang, Q. Enhanced energy storage and dielectric properties of Bi0.487Na0.427K0.06Ba0.026TiO3xCeO2 anti-ferroelectric ceramics. J. Alloys Compd. 2016, 664, 632− 638. (11) Xie, J.; Hao, H.; Liu, H.; Yao, Z.; Song, Z.; Zhang, L.; Xu, Q.; Dai, J.; Cao, M. Dielectric relaxation behavior and energy storage properties of Sn modified SrTiO3 based ceramics. Ceram. Int. 2016, 42, 12796−12801. (12) Zhang, G.; Liu, S.; Yu, Y.; Zeng, Y.; Zhang, Y.; Hu, X.; Jiang, S. Microstructure and electrical properties of (Pb0.87Ba0.1La0.02)10221

DOI: 10.1021/acssuschemeng.7b02203 ACS Sustainable Chem. Eng. 2017, 5, 10215−10222

Research Article

ACS Sustainable Chemistry & Engineering

(51) Li, L.; Yu, X.; Cai, H.; Liao, Q.; Han, Y.; Gao, Z. Preparation and dielectric properties of BaCu(B2O5)-doped SrTiO3-based ceramics for energy storage. Mater. Sci. Eng., B 2013, 178, 1509−1514. (52) Puli, V. S.; Pradhan, D. K.; Chrisey, D. B.; Tomozawa, M.; Sharma, G. L.; Scott, J. F.; Katiyar, R. S. Structure, dielectric, ferroelectric, and energy density properties of (1-x)BZT-xBCT ceramic capacitors for energy storage applications. J. Mater. Sci. 2013, 48, 2151−2157. (53) Xu, Q.; Liu, H.; Song, Z.; Huang, X.; Ullah, A.; Zhang, L.; Xie, J.; Hao, H.; Cao, M.; Yao, Z. A new energy-storage ceramic system based on Bi0.5Na0.5TiO3 ternary solid solution. J. Mater. Sci.: Mater. Electron. 2016, 27, 322−329. (54) Li, Q.; Wang, J.; Liu, Z.; Dong, G.; Fan, H. Enhanced energystorage properties of BaZrO3-modified 0.80 Bi0.5Na0.5TiO3-0.20 Bi0.5K0.5TiO3 lead-free ferroelectric ceramics. J. Mater. Sci. 2016, 51, 1153−1160. (55) Xu, Q.; Li, T.; Hao, H.; Zhang, S.; Wang, Z.; Cao, M.; Yao, Z.; Liu, H. Enhanced energy storage properties of NaNbO3 modified Bi0.5Na0.5TiO3 based ceramics. J. Eur. Ceram. Soc. 2015, 35, 545−553. (56) Liu, X.; Du, H.; Liu, X.; Shi, J.; Fan, H. Energy storage properties of BiTi0.5Zn0.5O3-Bi0.5Na0.5TiO3-BaTiO3 relaxor ferroelectrics. Ceram. Int. 2016, 42, 17876−17879. (57) Pu, Y.; Yao, M.; Zhang, L.; Jing, P. High energy storage density of 0.55 Bi0.5Na0.5TiO3-0.45Ba0.85Ca0.15Ti0.9‑xZr0.1SnxO3 ceramics. J. Alloys Compd. 2016, 687, 689−695. (58) Wu, L.; Wang, X.; Li, L. Lead-free BaTiO3-Bi(Zn2/3Nb1/3)O3 weakly coupled relaxor ferroelectric materials for energy storage. RSC Adv. 2016, 6, 14273−14282. (59) Zheng, D.; Zuo, R.; Zhang, D.; Li, Y. Novel BiFeO3-BaTiO3Ba(Mg1/3Nb2/3)O3 lead-free relaxor ferroelectric ceramics for energystorage capacitors. J. Am. Ceram. Soc. 2015, 98, 2692−2695. (60) Cao, W.; Li, W.; Dai, X.; Zhang, T.; Sheng, J.; Hou, Y.; Fei, W. Large electrocaloric response and high energy-storage properties over a broad temperature range in lead-free NBT-ST ceramics. J. Eur. Ceram. Soc. 2016, 36, 593−600. (61) Zheng, D.; Zuo, R. Enhanced energy storage properties in La(Mg1/2Ti1/2)O3-modified BiFeO3-BaTiO3 lead-free relaxor ferroelectric ceramics within a wide temperature range. J. Eur. Ceram. Soc. 2017, 37, 413−418. (62) Cao, W.; Li, W.; Zhang, T.; Sheng, J.; Hou, Y.; Feng, Y.; Yu, Y.; Fei, W. High-energy storage density and efficiency of (1-x)[0.94NBT0.06BT]-xST lead-free ceramics. Energy Technol. 2015, 3, 1198−1204.

accompanied by enhanced interface polarization in annealed microwave-sintered BST. J. Am. Ceram. Soc. 2015, 98, 3212−3222. (33) Correia, T. M.; Millen, M. M.; Rokosz, M. K.; Weaver, P. M.; Gregg, J. M.; Viola, G.; Cain, M. G. A lead-free and high-energy density ceramic for energy storage applications. J. Am. Ceram. Soc. 2013, 96, 2699−2702. (34) Wang, T.; Jin, L.; Shu, L.; Hu, Q.; Wei, X. Energy storage properties in Ba0.4Sr0.6TiO3 ceramics with addition of semi-conductive BaO-B2O3-SiO2-Na2CO3-K2CO3 glass. J. Alloys Compd. 2014, 617, 399−403. (35) Wu, L.; Wang, X.; Gong, H.; Hao, Y.; Shen, Z.; Li, L. Coresatellite BaTiO3@SrTiO3 assemblies for a local compositionally graded relaxor ferroelectric capacitor with enhanced energy storage density and high energy efficiency. J. Mater. Chem. C 2015, 3, 750−758. (36) Huang, Y.; Wu, Y.; Qiu, W.; Li, J.; Chen, X. Enhanced energy storage density of Ba0.4Sr0.6TiO3-MgO composite prepared by spark plasma sintering. J. Eur. Ceram. Soc. 2015, 35, 1469−1476. (37) Cui, C.; Pu, Y.; Gao, Z.; Wan, J.; Guo, Y.; Hui, C.; Wang, Y.; Cui, Y. Structure, dielectric and relaxor properties in lead-free ST-NBT ceramics for high energy storage applications. J. Alloys Compd. 2017, 711, 319−326. (38) Zhu, M.; Hu, H.; Lei, N.; Hou, Y.; Yan, H. Dependence of depolarization temperature on cation vacancies and lattice distortion for lead-free 74 Bi1/2Na1/2TiO3-20.8 Bi1/2K1/2TiO3-5.2BaTiO3 ferroelectric ceramics. Appl. Phys. Lett. 2009, 94, 182901. (39) Xu, Q.; Chen, M.; Chen, W.; Liu, H.; Kim, B.; Ahn, B. Effect of CoO additive on structure and electrical properties of (Na0.5Bi0.5)0.93Ba0.07TiO3 ceramics prepared by the citrate method. Acta Mater. 2008, 56, 642−650. (40) Jin, C. C.; Wang, F. F.; Yao, Q. R.; Tang, Y. X.; Wang, T.; Shi, W. Z. Ferroelectric, dielectric properties and large strain response in Zr-modified (Bi0.5Na0.5)TiO3-BaTiO3 lead-free ceramics. Ceram. Int. 2014, 40, 6143−6150. (41) Wang, Y.; Cui, J.; Yuan, Q.; Niu, Y.; Bai, Y.; Wang, H. Significantly enhanced breakdown strength and energy density in sandwich-structured barium titanate/ poly(vinylidene fluoride) nanocomposites. Adv. Mater. 2015, 27, 6658−6663. (42) Shao, T.; Du, H.; Ma, H.; Qu, S.; Wang, J.; Wang, J.; Wei, X.; Xu, Z. Potassium-sodium niobate based lead-free ceramics: novel electrical energy storage materials. J. Mater. Chem. A 2017, 5, 554− 563. (43) Tuncer, E.; James, D. R.; Sauers, I.; Ellis, A. R.; Pace, M. O. On dielectric breakdown statistics. J. Phys. D: Appl. Phys. 2006, 39, 4257− 4268. (44) Su, X.; Riggs, B. C.; Tomozawa, M.; Nelson, J. K.; Chrisey, D. B. Preparation of BaTiO3/low melting glass core-shell nanoparticles for energy storage capacitor applications. J. Mater. Chem. A 2014, 2, 18087−18096. (45) Huang, J.; Zhang, Y.; Ma, T.; Li, H.; Zhang, L. Correlation between dielectric breakdown strength and interface polarization in barium strontium titanate glass ceramics. Appl. Phys. Lett. 2010, 96, 042902. (46) Li, Y.; Liu, H.; Yao, Z.; Xu, J.; Cui, Y.; Hao, H.; Cao, M.; Yu, Z. Characterization and energy storage density of BaTiO3 -Ba(Mg1/3Nb2/3)O3 ceramics. Mater. Sci. Forum 2010, 654, 2045−2048. (47) Wang, H.; Liu, J.; Zhai, J.; Shen, B. Ultra high energy-storage density in the barium potassium niobate-based glass-ceramics for energy-storage applications. J. Am. Ceram. Soc. 2016, 99, 2909−2912. (48) Yang, H.; Yan, F.; Lin, Y.; Wang, T.; He, L.; Wang, F. A lead free relaxation and high energy storage efficiency ceramics for energy storage applications. J. Alloys Compd. 2017, 710, 436−445. (49) Li, W.; Zhou, D.; Pang, L. Structure and energy storage properties of Mn-doped (Ba,Sr)TiO3-MgO composite ceramics. J. Mater. Sci.: Mater. Electron. 2017, 28, 8749−8754. (50) Ye, X.; Li, Y.; Bian, J. Dielectric and energy storage properties of Mn-doped Ba0.3Sr0.475La0.12Ce0.03TiO3 dielectric ceramics. J. Eur. Ceram. Soc. 2017, 37, 107−114. 10222

DOI: 10.1021/acssuschemeng.7b02203 ACS Sustainable Chem. Eng. 2017, 5, 10215−10222