本研究採用固相燒結法於空氣中燒結，製備銻摻雜之高熵(Na0.2Bi0.2K0.2La0.2Sr0.2)(Ti1-xSbx)O3(x=0-0.07)無鉛介電陶瓷系統，該系統透過在A- site引入等莫耳比之五元陽離子，成功將晶格之組態熵(∆S_conf)最大化，形成具備高度局部化學無序與強烈應變的母相。然而僅憑高熵效應所建構的母相，雖然有助於降低殘餘極化並提升儲能效率，卻仍難以同步解決高溫燒結過程中因鉍等易揮發元素所誘發之氧空缺等缺陷問題，此類缺陷極易導致漏電流上升與擊穿電場強度下降，進而限制可回收儲能密度的提升空間，為突破此一瓶頸，本研究進一步藉由高熵效應，利用銻易產生〖Sb〗^(3+)及〖Sb〗^(5+)的雙價態特性進行改質設計，以提升介電電容儲能性能。
透過X光繞射儀分析與擬合計算結果顯示，隨著銻摻雜量的增加，樣品內部出現局部的鈣鈦礦母相向燒綠石相的結構轉變。結合晶體化學理論可知，由於〖Sb〗^(3+)進入A-site引發強烈的晶格扭曲，進一步促使燒綠石相析出。藉由此種於鈣鈦礦基質形成的燒綠石相以阻止高電場下擊穿通道的產生，以提升材料的擊穿電場強度。
在缺陷方面，透過X射線光電子能譜結果擬合證實，隨著銻摻雜量由x=0增加至x=0.07，樣品中〖Ti〗^(3+)鍵結比例由22%降至12%，氧空缺Ov比例由54%降至24%，同時代表低價鉍之〖Bi〗^(2+)亦接近消失。此一系列缺陷濃度的下降，與〖Sb〗^(5+)進入B-site位置取代〖Ti〗^(4+)所誘導之電荷補償機制相符，顯示〖Sb〗^(5+)於B-site之取代對於改善材料電絕緣性具有關鍵作用。
透過二次相的形成以及減少缺陷的雙重策略，提升材料的能隙與絕緣電阻率，大幅降低漏電流並提升擊穿電場強度，使樣品展現極佳的儲能表現。在700kV/cm的高電場下，其可回收儲能密度高達 8.15 J/cm³，儲能效率則提升至89.24%；與近期高熵無鉛介電儲能電容的文獻相比，擊穿電場普遍介於180-620 kV/cm，鮮少有體系之擊穿電場強度超越700kV/cm。此外，透過韋伯統計分析顯示其韋伯模數β為16.78，就可靠度而言，文獻普遍以韋伯模數β>10作為判斷樣品是否具有良好電性均勻性之基本門檻，本研究不僅高於此一門檻，亦與近期同類高熵陶瓷文獻中β介於11.81至22.22之間相符，顯示樣品具備極佳可靠度。
綜合上述結果，本研究證實透過銻的多價態摻雜能有效誘發高熵陶瓷之相變與抑制缺陷，使擊穿電場強度大幅提升，令樣品在儲能電容領域極具發展潛力。

Lead-free (Na0.2Bi0.2K0.2La0.2Sr0.2)(Ti1-xSbx)O3 (x=0-0.07) high-entropy ceramics based on the ABO3 perovskite structure were synthesized by solid-state sintering in air at 1150˚C. Five equimolar cations were introduced at the A-site, forming a highly disordered matrix. High-entropy effects led to an enhanced energy storage efficiency due to a small remnant polarization. However, there were other problems remained, such as the defects caused by preferential loss of volatile elements during sintering at high temperature, which resulted in large leakage current and hence a low dielectric breakdown strength (Eb). As a result, the recoverable energy density (Wrec) was limited. To minimize the problem, the high-entropy ceramics were doped with Sb. X-ray diffraction analysis showed that the perovskite phase in the samples was partially transformed into pyrochlore structure due to a large distortion of the Sb doping at A-site. The segregated grains of pyrochlore phase blocked the electric conducting channels when a large external field was applied. As a result, Eb was increased significantly. X-ray photoelectron spectroscopy (XPS) showed that both Sb3+ and Sb5+ were present in the samples. Mixed oxidation states of Ti3+ and Ti4+ were also observed in XPS, and the Ti3+ proportion decreased from 22% to 12% due to Sb doping, which also resulted in a decrease in both oxygen vacancies and Bi2+ ions. This was consistent with the need for charge compensation and helped to reduce leakage current, leading to a further improvement in Eb. Weibull analysis showed that the samples had a reliable Eb of 701 kV/cm, which was very high. As a result, a very high Wrec of 8.15 J/cm3 was achieved.

[1]L. Zhang, Y. Pu, M. Chen, X. Peng, B. Wang, and J. Shang, "Design strategies of perovskite energy-storage dielectrics for next-generation capacitors," Journal of the European Ceramic Society, vol. 43, no. 14, pp. 5713–5747, 2023.
[2]S. Pattnaik, M. R. Kumar, S. K. Mishra, and S. P. Gautam, "A review on characterization of supercapacitors and its efficiency analysis for different charging methods and applications," Energy Storage, vol. 5, no. 4, p. e398, 2023.
[3]H. Palneedi, M. Peddigari, G. T. Hwang, D. Y. Jeong, and J. Ryu, "High‐performance dielectric ceramic films for energy storage capacitors: progress and outlook," Advanced Functional Materials, vol. 28, no. 42, p. 1803665, 2018.
[4]F. Yan, J. Qian, S. Wang, and J. Zhai, "Progress and outlook on lead-free ceramics for energy storage applications," Nano Energy, vol. 123, p. 109394, 2024.
[5]B. Guo, F. Jin, L. Li, Z. Z. Pan, X. W. Xu, and H. Wang, "Design strategies of high‐performance lead‐free electroceramics for energy storage applications," Rare Metals, vol. 43, no. 3, pp. 853–878, 2024.
[6]X. Zhou et al., "High-Entropy Ferroelectric-Ferroelastic Hybrid for Ultrahigh and Temperature-Insensitive Dielectric Energy Storage," Advanced Science, vol. 13, no. 6, p. e18725, 2026.
[7]W. Yang and G. Zheng, "High energy storage density and efficiency in nanostructured (Bi0. 2Na0. 2K0. 2La0. 2Sr0. 2) TiO3 high‐entropy ceramics," Journal of the American Ceramic Society, vol. 105, no. 2, pp. 1083–1094, 2022.
[8]P. Kour and S. K. Pradhan, "Perovskite Ferroelectric," in Multifunctional Ferroelectric Materials, D. R. Sahu Ed. London: IntechOpen, 2021.
[9]K. Kumar, B. Singh, M. K. Gupta, N. Sinha, and B. Kumar, "Enhancement in dielectric and ferroelectric properties of lead free Bi0. 5 (Na0. 5K0. 5) 0.5 TiO3 ceramics by Sb-doping," Ceramics International, vol. 37, no. 8, pp. 2997–3004, 2011.
[10] M. Verma, A. Tanwar, and K. Sreenivas, "Influence of lone pair on structural and electrical properties of Sb substituted Bismuth layered SrBi2Nb2O9 ceramics," Materials Chemistry and Physics, vol. 209, pp. 159–164, 2018.
[11] K.-Y. Chan, B. Jia, H. Lin, N. Hameed, J.-H. Lee, and K.-T. Lau, "A critical review on multifunctional composites as structural capacitors for energy storage," Composite Structures, vol. 188, pp. 126–142, 2018.
[12] M. USMAN, "Studies of Ferroelectric and Multiferroic Behavior in [Ba (Zr, Ti) O3] 1-y:[CoFe2O4] y System," Quaid-i-Azam University, Islamabad, 2015.
[13] J. Lu and C. P. Wong, "Nanoparticle-Based High-k Dielectric Composites: Opportunities and Challenges", pp. 121–137, 2008.
[14] U. Böttger, "Dielectric Properties of Polar Oxides," in Polar Oxides, pp. 11–38, 2004,.
[15] P. Q. Mantas, "Dielectric response of materials: extension to the Debye model," Journal of the European Ceramic Society, vol. 19, no. 12, pp. 2079–2086, 1999.
[16] "Debye, P., Polar Molecules. 1929, New York: Chemical Catalog Co. 172 pp.," 1929.
[17] A. R. Von Hippel, Dielectrics and Waves. Wiley, 1954.
[18] Z. Yu and C. Ang, "Maxwell–Wagner polarization in ceramic composites BaTiO3–(Ni0.3Zn0.7)Fe2.1O4," Journal of Applied Physics, vol. 91, no. 2, pp. 794–797, 2002.
[19] J. T. S. Irvine, D. C. Sinclair, and A. R. West, "Electroceramics: Characterization by Impedance Spectroscopy," Advanced Materials, vol. 2, no. 3, pp. 132–138, 1990.
[20] K. S. Cole and R. H. Cole, "Dispersion and Absorption in Dielectrics I. Alternating Current Characteristics," The Journal of Chemical Physics, vol. 9, no. 4, pp. 341–351, 1941.
[21] K. C. Kao, Dielectric phenomena in solids. Elsevier, 2004.
[22] T. Sareein, P. Deeyai, B. Putasaeng, and N. Chathirat, "Electrical properties of Y2NiMnO6 ceramics sintered at high temperature," Applied Mechanics and Materials, vol. 804, pp. 55–58, 2015.
[23] D. O’Neill, R. M. Bowman, and J. M. Gregg, "Dielectric enhancement and Maxwell–Wagner effects in ferroelectric superlattice structures," Applied Physics Letters, vol. 77, no. 10, pp. 1520–1522, 2000.
[24] A. K. Jonscher, "The ‘universal’ dielectric response," Nature, vol. 267, no. 5613, pp. 673–679, 1977.
[25] K. J. Andrew, "Dielectric relaxation in solids," Journal of Physics D: Applied Physics, vol. 32, no. 14, p. R57, 1999.
[26] C.-J. Chang and X. Qi, "Dielectric relaxation and high recoverable energy density in (1-x)(0.3 BiFeO3-0.7 SrTiO3)-xK0. 5Na0. 5NbO3 ceramics," Ceramics International, vol. 48, no. 17, pp. 25610–25620, 2022.
[27] Z. Yang, H. Du, L. Jin, and D. Poelman, "High-performance lead-free bulk ceramics for electrical energy storage applications: design strategies and challenges," Journal of Materials Chemistry A, vol. 9, no. 34, pp. 18026–18085, 2021.
[28] G. Wang et al., "Electroceramics for High-Energy Density Capacitors: Current Status and Future Perspectives," Chemical Reviews, vol. 121, no. 10, pp. 6124–6172, 2021.
[29] I. Castillo, K. K. Mishra, and R. S. Katiyar, "Phase Transition and Energy Storage Density in Lead-Free Ferroelectric Ba1− xSrxTiO3 (x= 0.1, 0.3, and 0.7) Capacitors," Crystals, vol. 13, no. 4, p. 630, 2023.
[30] L. Jin, F. Li, and S. Zhang, "Decoding the Fingerprint of Ferroelectric Loops: Comprehension of the Material Properties and Structures," Journal of the American Ceramic Society, vol. 97, no. 1, pp. 1–27, 2014.
[31] F. Li, S. Zhang, D. Damjanovic, L. Q. Chen, and T. R. Shrout, "Local structural heterogeneity and electromechanical responses of ferroelectrics: learning from relaxor ferroelectrics," Advanced Functional Materials, vol. 28, no. 37, p. 1801504, 2018.
[32] A. A. Bokov and Z.-G. Ye, "Dielectric relaxation in relaxor ferroelectrics," Journal of Advanced dielectrics, vol. 2, no. 02, p. 1241010, 2012.
[33] S. Pattipaka, Y. Lim, Y. H. Son, Y. M. Bae, M. Peddigari, and G.-T. Hwang, "Ceramic-based dielectric materials for energy storage capacitor applications," Materials, vol. 17, no. 10, p. 2277, 2024.
[34] W. Weibull, "A statistical distribution function of wide applicability," Journal of applied mechanics, 1951.
[35] P. Shi, H. Li, Y. Zhou, Z. Wang, and Y. Wang, "Energy-Storage Performance of High-Entropy (NaBiBa)0.205 (SrCa)0.1925TiO3-La(Mg0.5Zr0.5)O3 Ceramic Under Moderate Electric Fields," Energies, vol. 18, no. 21, p. 5838, 2025.
[36] J.-W. Yeh et al., "Nanostructured High-Entropy Alloys with Multiple Principal Elements: Novel Alloy Design Concepts and Outcomes," Advanced Engineering Materials, vol. 6, no. 5, pp. 299–303, 2004.
[37] Y. Jien-Wei, "Recent progress in high entropy alloys," ann. Chim. sci. Mat, vol. 31, no. 6, pp. 633–648, 2006.
[38] H. Wang et al., "Entropy manipulation of SrTiO3 perovskite for enhanced thermoelectric and mechanical properties," Inorganic Chemistry, vol. 63, no. 52, pp. 24724–24735, 2024.
[39] J. Lee, J. H. Seo, B. Gao, and H. W. Jang, "Transition Metal‐Based High‐Entropy Materials for Catalysis," MetalMat, vol. 2, no. 1, p. e31, 2025.
[40] M. Wang et al., "Entropy engineering of La-based perovskite for simultaneous photocatalytic CO2 reduction and biomass oxidation," Chemical Communications, vol. 59, 2023.
[41] F. Yu et al., "High‐Entropy Solid‐State Electrolytes for Rechargeable Batteries: Mechanism, Structural Designs, Characterizations, and Applications," Small, vol. 21, 2025.
[42] V. M. Goldschmidt, "Die gesetze der krystallochemie," Naturwissenschaften, vol. 14, no. 21, pp. 477–485, 1926.
[43] M. Subramanian, G. Aravamudan, and G. S. Rao, "Oxide pyrochlores—a review," Progress in Solid State Chemistry, vol. 15, no. 2, pp. 55–143, 1983.
[44] K. Yeon Jung, "Dielectric Characteristics of BaTiO3 Solid Solution Substituted with Nb5+, Ta5, Bi3+, and Sb3+ Ions," Applied Science and Convergence Technology, vol. 32, no. 5, pp. 101–105, 2023.
[45] S. Wang et al., "Embedding Plate-Like Pyrochlore in Perovskite Phase to Enhance Energy Storage Performance of BNT-Based Ceramic Capacitors," Advanced Energy Materials, vol. 15, no. 12, p. 2403926, 2025.
[46] C. Long, Q. Chang, and H. Fan, "Differences in nature of electrical conductions among Bi4Ti3O12-based ferroelectric polycrystalline ceramics," Scientific Reports, vol. 7, no. 1, p. 4193, 2017.
[47] G. B. Ge, J. Y. Zhuang, F. Zhang, Y. L. Chen, Y. Umeda, and J. T. Huang, "Antimony doping effect on barium strontium titanate," Key Engineering Materials, vol. 512, pp. 1150–1154, 2012.
[48] B. J. Inkson, "Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) for materials characterization," in Materials characterization using nondestructive evaluation (NDE) methods: Elsevier, pp. 17–43, 2016.
[49] K. Dieng, "Caractérisation et modélisation de nouvelles capacités «Through Silicon Capacitors» à forte intégration pour la réduction de consommation et la montée en fréquence dans les architectures 3D de circuits intégrés," Université Grenoble Alpes, 2016.
[50] 王凱郁, "固相合成之銻摻雜鐵酸鉍-鈦酸鍶-鈮酸鈉介電陶瓷電容儲能性質及電性分析," 2023.
[51] A. Vandenbroucke, "Abatement of volatile organic compounds by combined use of non-thermal plasma and heterogeneous catalysis," Ghent University, 2015.
[52] D. Regonini, "Anodised TiO2 nanotubes: synthesis, growth mechanism and thermal stability," University of Bath Bath, UK, 2008.
[53] P. Kubelka and F. Munk, "An article on optics of paint layers," Z. Tech. Phys, vol. 12, no. 593-601, pp. 259–274, 1931.
[54] B. M. Weckhuysen and R. A. Schoonheydt, "Recent progress in diffuse reflectance spectroscopy of supported metal oxide catalysts," Catalysis today, vol. 49, no. 4, pp. 441–451, 1999.
[55] N. Izyumskaya, Y.-I. Alivov, S.-J. Cho, H. Morkoç, H. Lee, and Y.-S. Kang, "Processing, structure, properties, and applications of PZT thin films," Critical reviews in solid state and materials sciences, vol. 32, no. 3-4, pp. 111–202, 2007.
[56] K. Bunpang, S. Singkammo, D. P. Cann, and N. Raengthon, "Titanate-based high-entropy perovskite oxides relaxor ferroelectrics," Scientific Reports, vol. 14, no. 1, p. 6017, 2024.
[57] W. Cao et al., "Interfacial‐Polarization Engineering in BNT‐Based Bulk Ceramics for Ultrahigh Energy‐Storage Density," Advanced Science, vol. 11, no. 48, p. 2409113, 2024.
[58] S. K. Mev, S. Chahal, and S. Asthana, "Cationic Engineering of a Sr2+-Modified Na0.5Bi0.5TiO3-Based Ferroelectric Material for Ultra-High Energy Efficiency and Energy Harvesting," ACS Applied Energy Materials, vol. 9, no. 6, pp. 3134–3149, 2026.
[59] J. Zha et al., "Excellent energy storage performance of Bi0.5Na0.5TiO3-based lead-free relaxor ferroelectrics via isovalent high-entropy doping," Journal of the European Ceramic Society, vol. 46, no. 2, p. 117837, 2026.
[60] J. Zhang et al., "Achieving superior energy storage density in BiFeO3-BaTiO3-based relaxor ceramics via configurational entropy tunning and phase structure evolution," Ceramics International, vol. 51, no. 3, pp. 4048–4057, 2025.
[61] Y. Zheng et al., "Enhancing energy storage performance of BT-based ceramics by doping modification," Materials Science in Semiconductor Processing, vol. 196, p. 109656, 2025.
[62] W. Ye et al., "Enhanced low-field energy storage performance and dielectric stability in (Bi0.4Sr0.2K0.2Na0.2)(Ti1-xZrx)O3 high-entropy ceramics via B-site modification," Ceramics International, vol. 51, no. 1, pp. 584–592, 2025.
[63] L. Cui et al., "Improved low-field energy storage in BF-BT ceramics by tailoring B-site multivalent ions and BaTiO3 content," Ceramics International, vol. 51, no. 25, Part B, pp. 46083–46092, 2025.
[64] Z. Ge, H. Liu, J. G. Tang, S. W. Lee, and J. Li, "Dielectric and electrical energy storage properties of a series of high-entropy tetragonal tungsten bronze ceramics," Journal of Alloys and Compounds, vol. 1015, p. 178836, 2025.
[65] W. Zhao, Y. Chen, Y. Wang, D. Hu, L. Zhao, and B. Cui, "Enhancing the energy storage performance of (Na0.2Bi0.2Ba0.2Sr0.2Ca0.2)TiO3-based high-entropy fine-grained ceramics with core–shell structure," Ceramics International, vol. 51, no. 20, Part A, pp. 30921–30930, 2025.
[66] Y. Hui et al., "Entropy engineering toward superior energy storage density under low electric fields in BNKT-based bulk ceramics," Ceramics International, vol. 51, no. 22, Part A, pp. 36340–36348, 2025.
[67] C. Liu, Y. Kong, J. Zhang, C. Lyu, and H. Ma, "High energy storage performance in (Bi0.4Na0.2K0.2Ba0.2)TiO3-Bi(Zn2/3Ta1/3)O3 high-entropy ceramics with excellent temperature and frequency stability," Ceramics International, vol. 51, no. 13, pp. 17928–17935, 2025.
[68] J. L. Shimin Wang, Meng Xu, Fengzhen Huang, Yulong Yang, Jielin Zha, Xiaomei Lu and Jinsong Zhu, "Improved energy storage performance and thermal stability in (1−x)(Sr0.7Ba0.255Ca0.045Ti0.9Zr0.1O3)-xBi0.5Na0.5TiO3 ceramics with multiple synergistic design," J. Phys. D: Appl. Phys., vol. 58, Art no. 18, 2025.
[69] P. Mao et al., "Boosting High Electric Breakdown Strength for Excellent Energy Storage Performance in Bi0.5Na0.5TiO3-Based Lead-Free Ceramics via a High Entropy Strategy," ACS Applied Materials & Interfaces, vol. 17, no. 1, pp. 1485–1498, 2025.
[70] W.-Y. Hsiao and X. Qi, "Synthesis and characterization of (Na0. 2Bi0. 2Ba0. 2Sr0. 2Ca0. 2) TiO3-based high entropy ceramics with high recoverable energy density," Ceramics International, 2025.
[71] J. Ji et al., "Achieve high dielectric energy storage efficiency and good temperature stability within a wide range by high-entropy induced relaxor enhancement strategy in NBT-based ceramics," Chemical Engineering Journal, vol. 522, p. 167823, 2025.
[72] X. Zeng et al., "Polymorphic relaxor phase and defect dipole polarization co-reinforced capacitor energy storage in temperature-monitorable high-entropy ferroelectrics," Nature Communications, vol. 16, no. 1, p. 1870, 2025.
[73] Z. Luo et al., "Achieving Ultrahigh Energy Storage Density for BaTiO3-Based Ceramics under Moderate Electric Fields via Regulating Dielectric Permittivity," ACS Applied Materials & Interfaces, vol. 17, no. 19, pp. 28411–28424, 2025.
[74] L. Diwu et al., "Engineering Ordered-Disordered Domains for High-Performance Energy Storage in BCZT-Based Relaxor Ferroelectrics," Small, vol. 21, no. 26, p. 2503713, 2025.
[75]W. Xie et al., "Enhanced electrostatic energy-storage performances in the high-entropy Bi0. 5Na0. 5TiO3-based ceramic capacitors," Applied Physics Letters, vol. 126, no. 24, 2025.