[1] [1] YAO F Z, ZHANG M H, WANG K, et al. Refreshing piezoelectrics:Distinctive role of manganese in lead-free perovskites[J]. ACS Appl Mater Interfaces, 2018, 10(43): 37298–37306.

[2] [2] WOLNY W W. Application driven industrial development of piezoceramics[J]. J Eur Ceram Soc, 2005, 25(12): 1971–1976.

[3] [3] KHALYAVIN D D, JOHNSON R D, ORLANDI F, et al. Emergent helical texture of electric dipoles[J]. Science, 2020, 369(6504):680–684.

[4] [4] DAS S, TANG Y L, HONG Z, et al. Observation of room-temperature polar skyrmions[J]. Nature, 2019, 568(7752): 368–372.

[5] [5] TAKENAKA H, GRINBERG I, LIU S, et al. Slush-like polar structures in single-crystal relaxors[J]. Nature, 2017, 546(7658):391–395.

[6] [6] GAO B T, LIU H, ZHOU Z Y, et al. An intriguing canting dipole configuration and its evolution under an electric field in La-doped Pb(Zr, Sn, Ti)O3 perovskites[J]. Microstructures, 2022, 2(3):2022010.

[7] [7] LIU H, ZHOU Z Y, QIU Y, et al. An intriguing intermediate state as a bridge between antiferroelectric and ferroelectric perovskites[J].Mater Horiz, 2020, 7(7): 1912–1918.

[8] [8] GAO B T, LIU H, ZHOU Z Y, et al. An intriguing polarization configuration of mixed Ising- and Néel-type model in the prototype PbZrO3-based antiferroelectrics[J]. Inorg Chem, 2021, 60(5):3232–3237.

[9] [9] SHROUT T R, ZHANG S J. Lead–free piezoelectric ceramics:Alternatives for PZT?[J]. J Electroceram, 2007, 19(1): 185.

[10] [10] PANDA P, SAHOO B. PZT to lead free piezo ceramics: A review[J].Ferroelectrics, 2015, 474: 128–143.

[11] [11] LIU H, CHEN J, FAN L L, et al. Critical role of monoclinic polarization rotation in high-performance perovskite piezoelectric materials[J]. Phys Rev Lett, 2017, 119(1): 017601.

[12] [12] LIU H, CHEN J, HUANG H B, et al. Role of reversible phase transformation for strong piezoelectric performance at the morphotropic phase boundary[J]. Phys Rev Lett, 2018, 120(5): 055501.

[13] [13] LI F, LIN D B, CHEN Z B, et al. Ultrahigh piezoelectricity in ferroelectric ceramics by design[J]. Nat Mater, 2018, 17(4): 349–354.

[14] [14] LI F, CABRAL M J, XU B, et al. Giant piezoelectricity of Sm-doped Pb(Mg1/3Nb2/3)O3–PbTiO3 single crystals[J]. Science, 2019,364(6437): 264–268.

[15] [15] GUO Q H, LI F, XIA F Q, et al. High-performance Sm-doped Pb(Mg1/3Nb2/3)O3–PbZrO3–PbTiO3-based piezoceramics[J]. ACS Appl Mater Interfaces, 2019, 11(46): 43359–43367.

[16] [16] YAN Y K, GENG L D, ZHU L F, et al. Ultrahigh piezoelectric performance through synergistic compositional and microstructural engineering[J]. Adv Sci, 2022, 9(14): e2105715.

[17] [17] FU J, ZUO R Z. Structural evidence for the polymorphic phase boundary in (Na, K)NbO3 based perovskites close to the rhombohedral–tetragonal phase coexistence zone[J]. Acta Mater,2020, 195: 571–578.

[18] [18] LIU W F, REN X B. Large piezoelectric effect in Pb-free ceramics[J].Phys Rev Lett, 2009, 103(25): 257602.

[19] [19] YAO Y G, ZHOU C, LV D C, et al. Large piezoelectricity and dielectric permittivity in BaTiO3–xBaSnO3 system: The role of phase coexisting[J]. EPL Europhys Lett, 2012, 98(2): 27008.

[20] [20] ZHAO C L, WU H J, LI F, et al. Practical high piezoelectricity in Barium titanate ceramics utilizing multiphase convergence with broad structural flexibility[J]. J Am Chem Soc, 2018, 140(45):15252–15260.

[21] [21] WANG D W, FAN Z M, RAO G H, et al. Ultrahigh piezoelectricity in lead-free piezoceramics by synergistic design[J]. Nano Energy,2020, 76: 104944.

[22] [22] WU J G, XIAO D Q, ZHU J G. Potassium-sodium niobate lead-free piezoelectric materials: Past, present, and future of phase boundaries[J]. Chem Rev, 2015, 115(7): 2559–2595.

[23] [23] SAITO Y, TAKAO H, TANI T, et al. Lead-free piezoceramics[J]. Nature, 2004, 432(7013): 84–87.

[24] [24] ZUO R Z, FU J A, LV D Y. Phase transformation and tunable piezoelectric properties of lead-free (Na0.52K0.48–xLix) (Nb1–x–ySbyTax)O3 system[J]. J Am Ceram Soc, 2009, 92(1): 283–285.

[25] [25] ZUO R Z, FU J A, LV D Y, et al. Antimony tuned rhombohedral–orthorhombic phase transition and enhanced piezoelectric properties in sodium potassium niobate[J]. J Am Ceram Soc, 2010, 93(9): 2783–2787.

[26] [26] ZUO R Z, FU J A. Rhombohedral–tetragonal phase coexistence and piezoelectric properties of (NaK)(NbSb)O3–LiTaO3–BaZrO3 lead-free ceramics[J]. J Am Ceram Soc, 2011, 94(5): 1467–1470.

[27] [27] WANG K, YAO F Z, JO W, et al. Temperature-insensitive (K,Na)NbO3-based lead-free piezoactuator ceramics[J]. Adv Funct Materials, 2013, 23(33): 4079–4086.

[28] [28] ZHOU C M, ZHANG J L, YAO W Z, et al. Remarkably strong piezoelectricity, rhombohedral–orthorhombic–tetragonal phase coexistence and domain structure of (K, Na)(Nb, Sb)O3–(Bi,Na)ZrO3–BaZrO3 ceramics[J]. J Alloys Compd, 2020, 820: 153411.

[29] [29] TAO H, WU H J, LIU Y, et al. Ultrahigh performance in lead-free piezoceramics utilizing a relaxor slush polar state with multiphase coexistence[J]. J Am Chem Soc, 2019, 141(35): 13987–13994.

[30] [30] LI P, ZHAI J W, SHEN B, et al. Ultrahigh piezoelectric properties in textured (K, Na)NbO3-based lead-free ceramics[J]. Adv Mater, 2018,30(8): 1705171.

[31] [31] YEH J W, CHEN S K, LIN S J, et al. Nanostructured high-entropy alloys with multiple principal elements: Novel alloy design concepts and outcomes[J]. Adv Eng Mater, 2004, 6(5): 299–303.

[32] [32] CANTOR B, CHANG I T H, KNIGHT P, et al. Microstructural development in equiatomic multicomponent alloys[J]. Mater Sci Eng A, 2004, 375–377: 213–218.

[33] [33] OSES C, TOHER C, CURTAROLO S. High-entropy ceramics[J].Nat Rev Mater, 2020, 5(4): 295–309.

[34] [34] SARKAR A, WANG Q S, SCHIELE A, et al. High-entropy oxides:Fundamental aspects and electrochemical properties[J]. Adv Mater,2019, 31(26): e1806236.

[35] [35] SARKAR A, VELASCO L, WANG D, et al. High entropy oxides for reversible energy storage[J]. Nat Commun, 2018, 9(1): 3400.

[36] [36] QIAN X S, HAN D L, ZHENG L R, et al. High-entropy polymer produces a giant electrocaloric effect at low fields[J]. Nature, 2021,600(7890): 664–669.

[37] [37] MA Y J, MA Y, WANG Q S, et al. High-entropy energy materials:Challenges and new opportunities[J]. Energy Environ Sci, 2021,14(5): 2883–2905.

[38] [38] JIANG B B, YU Y, CUI J, et al. High-entropy-stabilized chalcogenides with high thermoelectric performance[J]. Science,2021, 371(6531): 830–834.

[39] [39] MIRACLE D B, SENKOV O N. A critical review of high entropy alloys and related concepts[J]. Acta Mater, 2017, 122: 448–511.

[40] [40] KUMARI P, GUPTA A K, MISHRA R K, et al. A comprehensive review: Recent progress on magnetic high entropy alloys and oxides[J]. J Magn Magn Mater, 2022, 554: 169142.

[41] [41] AKRAMI S, EDALATI P, FUJI M, et al. High-entropy ceramics:Review of principles, production and applications[J]. Mater Sci Eng R Rep, 2021, 146: 100644.

[42] [42] GEORGE E P, RAABE D, RITCHIE R O. High-entropy alloys[J].Nat Rev Mater, 2019, 4(8): 515–534.

[43] [43] ZHANG W R, LIAW P K, ZHANG Y. Science and technology in high-entropy alloys[J]. Sci China Mater, 2018, 61(1): 2–22.

[44] [44] ROST C M, SACHET E, BORMAN T, et al. Entropy-stabilized oxides[J]. Nat Commun, 2015, 6: 8485.

[45] [45] TOHER C, OSES C, ESTERS M, et al. High-entropy ceramics: Propelling applications through disorder[J]. MRS Bull, 2022, 47(2):194–202.

[46] [46] ZHANG R Z, REECE M J. Review of high entropy ceramics: Design,synthesis, structure and properties[J]. J Mater Chem A, 2019, 7(39):22148–22162.

[47] [47] XIANG H M, XING Y, DAI F Z, et al. High-entropy ceramics:Present status, challenges, and a look forward[J]. J Adv Ceram, 2021,10(3): 385–441.

[48] [48] WRIGHT A J, LUO J. A step forward from high-entropy ceramics to compositionally complex ceramics: A new perspective[J]. J Mater Sci, 2020, 55(23): 9812–9827.

[49] [49] ZHANG M, XU X Z, AHMED S, et al. Phase transformations in an Aurivillius layer structured ferroelectric designed using the high entropy concept[J]. Acta Mater, 2022, 229: 117815.

[50] [50] ZHANG M, XU X Z, YUE Y J, et al. Multi elements substituted Aurivillius phase relaxor ferroelectrics using high entropy design concept[J]. Mater Des, 2021, 200: 109447.

[51] [51] HU Z M, ZHANG H F, REECE M J, et al. Relaxor ferroelectric behaviour observed in (Ca0.5Sr0.5Ba0.5Pb0.5)Nb2O7 perovskite layered structure ceramics[J]. J Eur Ceram Soc, 2023, 43(1): 177–182.

[52] [52] CHEN Y Y, QI J L, ZHANG M H, et al. Pyrochlore-based high-entropy ceramics for capacitive energy storage[J]. J Adv Ceram,2022, 11(7): 1179–1185.

[53] [53] LIU Y, YANG J Y, DENG S Q, et al. Flexible polarization configuration in high-entropy piezoelectrics with high performance[J].Acta Mater, 2022, 236: 118115.

[54] [54] LIU Z Y, XU S C, LI T, et al. Microstructure and ferroelectric properties of high-entropy perovskite oxides with A-site disorder[J].Ceram Int, 2021, 47(23): 33039–33046.

[55] [55] ZHANG Y Y, QI H, SUN S D, et al. Ultrahigh piezoelectric performance benefiting from quasi–isotropic local polarization distribution in complex lead-based perovskite[J]. Nano Energy, 2022,104: 107910.

[56] [56] ZHANG Y Y, LIU H, SUN S D, et al. High piezoelectric performance in Pb(Ni1/3Nb2/3)O3–Pb(Sc1/2Nb1/2)O3–PbTiO3 ternary system featuring small structural distortion and heterogeneous domain configuration[J]. ACS Appl Mater Interfaces, 2022, 14(11):13528–13538.

[57] [57] LI F, JIN L, XU Z, et al. Electrostrictive effect in ferroelectrics: An alternative approach to improve piezoelectricity[J]. Appl Phys Rev, 2014, 1(1): 011103.

[58] [58] ZHAO L, CHEN K, MA J, et al. Giant electrostrictive coefficient of KNN-based lead-free ferroelectrics[J]. Ceram Int, 2022, 48(19):28622–28628.

[59] [59] QI H, ZUO R Z. Giant electrostrictive strain in (Bi0.5Na0.5)TiO3–NaNbO3 lead-free relaxor antiferroelectrics featuring temperature and frequency stability[J]. J Mater Chem A, 2020, 8(5): 2369–2375.

[60] [60] LIU Y, DENG S Q, LI J, et al. High-performance electrostrictive relaxors with dispersive endotaxial nanoprecipitations[J]. Adv Mater,2022, 34(36): e2204743.

[61] [61] HUANG Y L, ZHAO C L, YIN J, et al. Giant electrostrictive effect in lead-free Barium titanate-based ceramics via A-site ion-pairs engineering[J]. J Mater Chem A, 2019, 7(29): 17366–17375.

[62] [62] WANG L, QI H, DENG S Q, et al. Design of superior electrostriction in BaTiO3based lead‐free relaxors via the formation of polarization nanoclusters[J]. Infomat, 2023, 5(1): e12362.

[63] [63] YANG L T, KONG X, LI F, et al. Perovskite lead-free dielectrics for energy storage applications[J]. Prog Mater Sci, 2019, 102: 72–108.

[64] [64] VEERAPANDIYAN V, BENES F, GINDEL T, et al. Strategies to improve the energy storage properties of perovskite lead-free relaxor ferroelectrics:A review[J]. Materials, 2020, 13(24): 5742.

[65] [65] WANG G, LU Z L, LI Y, et al. Electroceramics for high-energy density capacitors: Current status and future perspectives[J]. Chem Rev, 2021, 121(10): 6124–6172.

[66] [66] ZHOU S Y, PU Y P, ZHANG X Q, et al. High energy density,temperature stable lead-free ceramics by introducing high entropy perovskite oxide[J]. Chem Eng J, 2022, 427: 131684.

[67] [67] GUO J A, XIAO W R, ZHANG X Y, et al. Achieving excellent energy storage properties in fine-grain high-entropy relaxor ferroelectric ceramics[J]. Adv Elect Mater, 2022, 8(11): 2200503.

[68] [68] QI H, ZUO R Z, XIE A W, et al. Ultrahigh energy–storage density in NaNbO3-based lead-free relaxor antiferroelectric ceramics with nanoscale domains[J]. Adv Funct Mater, 2019, 29(35): 1903877.

[69] [69] JIANG J, MENG X J, LI L, et al. Ultrahigh energy storage density in lead-free relaxor antiferroelectric ceramics via domain engineering[J].Energy Storage Mater, 2021, 43: 383–390.

[70] [70] CHEN J, QI H, ZUO R Z. Realizing stable relaxor antiferroelectric and superior energy storage properties in (Na1–x/2Lax/2)(Nb1–xTix)O3 lead-free ceramics through A/B-site complex substitution[J]. ACS Appl Mater Interfaces, 2020, 12(29): 32871–32879.

[71] [71] LIU J K, LI P, LI C Y, et al. Synergy of a stabilized antiferroelectric phase and domain engineering boosting the energy storage performance of NaNbO3-based relaxor antiferroelectric ceramics[J].ACS Appl Mater Interfaces, 2022, 14(15): 17662–17673.

[72] [72] QI H, ZUO R Z. Linear–like lead–free relaxor antiferroelectric(Bi0.5Na0.5)TiO3–NaNbO3 with giant energy-storage density/efficiency and super stability against temperature and frequency[J]. J Mater Chem A, 2019, 7(8): 3971–3978.

[73] [73] LI T Y, JIANG X W, LI J, et al. Ultrahigh energy-storage performances in lead-free Na0.5Bi0.5TiO3-based relaxor antiferroelectric ceramics through a synergistic design strategy[J]. ACS Appl Mater Interfaces, 2022, 14(19): 22263–22269.

[74] [74] JIANG J, LI X J, LI L, et al. Novel lead-free NaNbO3-based relaxor antiferroelectric ceramics with ultrahigh energy storage density and high efficiency[J]. J Materiomics, 2022, 8(2): 295–301.

[75] [75] QI H, XIE A W, TIAN A, et al. Superior energy-storage capacitors with simultaneously giant energy density and efficiency using nanodomain engineered BiFeO3–BaTiO3–NaNbO3 lead-free bulk ferroelectrics[J]. Adv Energy Mater, 2020, 10(6): 1903338.

[76] [76] YE H R, YANG F, PAN Z B, et al. Significantly improvement of comprehensive energy storage performances with lead-free relaxor ferroelectric ceramics for high-temperature capacitors applications[J].Acta Mater, 2021, 203: 116484.

[77] [77] CHEN L A, LONG F X, QI H, et al. Outstanding energy storage performance in high-hardness (Bi0.5K0.5)TiO3-based lead-free relaxors via multi-scale synergistic design[J]. Adv Funct Mater, 2022, 32(9):2110478.

[78] [78] CHEN L, LI F, GAO B T, et al. Excellent energy storage and mechanical performance in hetero-structure BaTiO3-based relaxors[J].Chem Eng J, 2023, 452: 139222.

[79] [79] QIAO X S, ZHANG F D, WU D, et al. Superior comprehensive energy storage properties in Bi0.5Na0.5TiO3-based relaxor ferroelectric ceramics[J]. Chem Eng J, 2020, 388: 124158.

[80] [80] LI D, ZHOU D, WANG D, et al. Improved energy storage properties achieved in (K, Na)NbO3-based relaxor ferroelectric ceramics via a combinatorial optimization strategy[J]. Adv Funct Materials, 2022,32(15): 2111776.

[81] [81] HU Q Y, TIAN Y, ZHU Q S, et al. Achieve ultrahigh energy storage performance in BaTiO3–Bi(Mg1/2Ti1/2)O3 relaxor ferroelectric ceramics via nano-scale polarization mismatch and reconstruction[J].Nano Energy, 2020, 67: 104264.

[82] [82] XIE A W, ZUO R Z, QIAO Z L, et al. NaNbO3–(Bi0.5Li0.5)TiO3 lead-free relaxor ferroelectric capacitors with superior energy-storage performances via multiple synergistic design[J]. Adv Energy Mater,2021, 11(28): 2101378.

[83] [83] ZHU L F, ZHAO L, YAN Y K, et al. Composition and strain engineered AgNbO3-based multilayer capacitors for ultra-high energy storage capacity[J]. J Mater Chem A, 2021, 9(15): 9655–9664.

[84] [84] LI S, HU T F, NIE H C, et al. Giant energy density and high efficiency achieved in silver niobate-based lead-free antiferroelectric ceramic capacitors via domain engineering[J]. Energy Storage Mater,2021, 34: 417–426.

[85] [85] ZHAO L, LIU Q, GAO J, et al. Lead-free antiferroelectric silver niobate tantalate with high energy storage performance[J]. Adv Mater,2017, 29(31): 1701824.

[86] [86] TIAN Y, JIN L, ZHANG H F, et al. Phase transitions in bismuth-modified silver niobate ceramics for high power energy storage[J]. J Mater Chem A, 2017, 5(33): 17525–17531.

[87] [87] LUO N N, HAN K, CABRAL M J, et al. Constructing phase boundary in AgNbO3 antiferroelectrics: Pathway simultaneously achieving high energy density and efficiency[J]. Nat Commun, 2020,11(1): 4824.

[88] [88] GE G L, SHI C, CHEN C K, et al. Tunable domain switching features of incommensurate antiferroelectric ceramics realizing excellent energy storage properties[J]. Adv Mater, 2022, 34(24): e2201333.

[89] [89] YANG Z T, DU H L, JIN L, et al. High-performance lead-free bulk ceramics for electrical energy storage applications: Design strategies and challenges[J]. J Mater Chem A, 2021, 9(34): 18026–18085.

[90] [90] WANG G, LI J L, ZHANG X, et al. Ultrahigh energy storage density lead-free multilayers by controlled electrical homogeneity[J]. Energy Environ Sci, 2019, 12(2): 582–588.

[91] [91] CUI T, ZHANG J, GUO J, et al. Simultaneous achievement of ultrahigh energy storage density and high efficiency in BiFeO3-based relaxor ferroelectric ceramics via a highly disordered multicomponent design[J]. J Mater Chem A, 2022, 10(27): 14316–14325.

[92] [92] LI J L, SHEN Z H, CHEN X H, et al. Grain-orientation-engineered multilayer ceramic capacitors for energy storage applications[J]. Nat Mater, 2020, 19(9): 999–1005.

[93] [93] LI Y, LIU Y, TANG M Y, et al. Energy storage performance of BaTiO3-based relaxor ferroelectric ceramics prepared through a two-step process[J]. Chem Eng J, 2021, 419: 129673.

[94] [94] CHEN L, WANG N, ZHANG Z F, et al. Local diverse polarization optimized comprehensive energy-storage performance in lead-free superparaelectrics[J]. Adv Mater, 2022, 34(44): e2205787.

[95] [95] CHEN L A, DENG S Q, LIU H, et al. Giant energy-storage density with ultrahigh efficiency in lead-free relaxors via high-entropy design[J]. Nat Commun, 2022, 13: 3089.

[96] [96] ZHANG S. High entropy design: A new pathway to promote the piezoelectricity and dielectric energy storage in perovskite oxides[J].Microstructures, 2022, 3(1): 2023003.

[97] [97] FANG J Q, WANG T, LI K, et al. Energy storage properties of Mn-modified (Na0.2Bi0.2Ca0.2Sr0.2Ba0.2)TiO3 high-entropy relaxorferroelectric ceramics[J]. Results Phys, 2022, 38: 105617.

[98] [98] SUN W Y, ZHANG F, ZHANG X, et al. Enhanced electrical properties of (Bi0.2Na0.2Ba0.2Ca0.2Sr0.2)TiO3 high-entropy ceramics prepared by hydrothermal method[J]. Ceram Int, 2022, 48(13):19492–19500.

[99] [99] NING Y T, PU Y P, ZHANG Q W, et al. Achieving high energy storage properties in perovskite oxide via high-entropy design[J].Ceram Int, 2023, 49(8): 12214–12223.

[100] [100] ZHOU C H, ZHANG X Y, LI S N, et al. Dielectric and energy storage properties of (La, Li)x[(Bi, Na)BaSrCa]1–xTiO3 high-entropy perovskite ceramics[J]. Ceram Int, 2022, 48(17): 24268–24275.

          ZHOU C H, ZHANG X Y, LI S N, et al. Dielectric and energy storage properties of (La, Li)x[(Bi, Na)BaSrCa]1–xTiO3 high-entropy perovskite ceramics[J]. Ceram Int, 2022, 48(17): 24268–24275.

[101] [101] CHEN L, YU H F, WU J, et al. Large energy capacitive high-entropy lead-free ferroelectrics[J]. Nanomicro Lett, 2023, 15(1): 65.

          CHEN L, YU H F, WU J, et al. Large energy capacitive high-entropy lead-free ferroelectrics[J]. Nanomicro Lett, 2023, 15(1): 65.

[102] [102] MA Q S, CHEN L, YU H F, et al. Excellent energy-storage performance in lead-free capacitors with highly dynamic polarization heterogeneous nanoregions[J]. Small, 2023, 19(47): e2303768.

          MA Q S, CHEN L, YU H F, et al. Excellent energy-storage performance in lead-free capacitors with highly dynamic polarization heterogeneous nanoregions[J]. Small, 2023, 19(47): e2303768.

[103] [103] YIP S. The strongest size[J]. Nature, 1998, 391(6667): 532–533.

          YIP S. The strongest size[J]. Nature, 1998, 391(6667): 532–533.

[104] [104] PALNEEDI H, PEDDIGARI M, HWANG G T, et al. High-performance dielectric ceramic films for energy storage capacitors: Progress and outlook[J]. Adv Funct Materials, 2018,28(42): 1803665.

          PALNEEDI H, PEDDIGARI M, HWANG G T, et al. High-performance dielectric ceramic films for energy storage capacitors: Progress and outlook[J]. Adv Funct Materials, 2018,28(42): 1803665.

[105] [105] CHENG H B, OUYANG J, ZHANG Y X, et al. Demonstration of ultra-high recyclable energy densities in domain-engineered ferroelectric films[J]. Nat Commun, 2017, 8(1): 1999.

          CHENG H B, OUYANG J, ZHANG Y X, et al. Demonstration of ultra-high recyclable energy densities in domain-engineered ferroelectric films[J]. Nat Commun, 2017, 8(1): 1999.

[106] [106] XU B, í?IGUEZ J, BELLAICHE L. Designing lead-free antiferroelectrics for energy storage[J]. Nat Commun, 2017, 8: 15682.

          XU B, í?IGUEZ J, BELLAICHE L. Designing lead-free antiferroelectrics for energy storage[J]. Nat Commun, 2017, 8: 15682.

[107] [107] SPAHR H, NOWAK C, HIRSCHBERG F, et al. Enhancement of the maximum energy density in atomic layer deposited oxide based thin film capacitors[J]. Appl Phys Lett, 2013, 103(4): 042907.

          SPAHR H, NOWAK C, HIRSCHBERG F, et al. Enhancement of the maximum energy density in atomic layer deposited oxide based thin film capacitors[J]. Appl Phys Lett, 2013, 103(4): 042907.

[108] [108] MICHAEL E K, TROLIER–MCKINSTRY S. Bismuth pyrochlore thin films for dielectric energy storage[J]. J Appl Phys, 2015, 118(5):054101.

          MICHAEL E K, TROLIER–MCKINSTRY S. Bismuth pyrochlore thin films for dielectric energy storage[J]. J Appl Phys, 2015, 118(5):054101.

[109] [109] WANG D X, CLARK M B Jr, TROLIER–MCKINSTRY S. Bismuth niobate thin films for dielectric energy storage applications[J]. J Am Ceram Soc, 2018, 101(8): 3443–3451.

          WANG D X, CLARK M B Jr, TROLIER–MCKINSTRY S. Bismuth niobate thin films for dielectric energy storage applications[J]. J Am Ceram Soc, 2018, 101(8): 3443–3451.

[110] [110] YANG B B, ZHANG Y, PAN H, et al. High-entropy enhanced capacitive energy storage[J]. Nat Mater, 2022, 21(9): 1074–1080.

          YANG B B, ZHANG Y, PAN H, et al. High-entropy enhanced capacitive energy storage[J]. Nat Mater, 2022, 21(9): 1074–1080.

[111] [111] YANG B B, ZHANG Q H, HUANG H B, et al. Engineering relaxors by entropy for high energy storage performance[J]. Nat Energy, 2023,8(9): 956–964.

          YANG B B, ZHANG Q H, HUANG H B, et al. Engineering relaxors by entropy for high energy storage performance[J]. Nat Energy, 2023,8(9): 956–964.

[112] [112] MISCHENKO A S, ZHANG Q, SCOTT J F, et al. Giant electrocaloric effect in thin-film PbZr0.95Ti 0.05O3[J]. Science, 2006,311(5765): 1270–1271.

          MISCHENKO A S, ZHANG Q, SCOTT J F, et al. Giant electrocaloric effect in thin-film PbZr0.95Ti 0.05O3[J]. Science, 2006,311(5765): 1270–1271.

[113] [113] MA R J, ZHANG Z Y, TONG K, et al. Highly efficient electrocaloric cooling with electrostatic actuation[J]. Science, 2017, 357(6356):1130–1134.

          MA R J, ZHANG Z Y, TONG K, et al. Highly efficient electrocaloric cooling with electrostatic actuation[J]. Science, 2017, 357(6356):1130–1134.

[114] [114] PENG B L, ZHANG Q, GANG B, et al. Phase-transition induced giant negative electrocaloric effect in a lead-free relaxor ferroelectric thin film[J]. Energy Environ Sci, 2019, 12(5): 1708–1717.

          PENG B L, ZHANG Q, GANG B, et al. Phase-transition induced giant negative electrocaloric effect in a lead-free relaxor ferroelectric thin film[J]. Energy Environ Sci, 2019, 12(5): 1708–1717.

[115] [115] NAIR B, USUI T, CROSSLEY S, et al. Large electrocaloric effects in oxide multilayer capacitors over a wide temperature range[J].Nature, 2019, 575(7783): 468–472.

          NAIR B, USUI T, CROSSLEY S, et al. Large electrocaloric effects in oxide multilayer capacitors over a wide temperature range[J].Nature, 2019, 575(7783): 468–472.

[116] [116] VALANT M. Electrocaloric materials for future solid-state refrigeration technologies[J]. Prog Mater Sci, 2012, 57(6): 980–1009.

          VALANT M. Electrocaloric materials for future solid-state refrigeration technologies[J]. Prog Mater Sci, 2012, 57(6): 980–1009.

[117] [117] LU S G, ZHANG Q M. Electrocaloric materials for solid-state refrigeration[J]. Adv Mater, 2009, 21(19): 1983–1987.

          LU S G, ZHANG Q M. Electrocaloric materials for solid-state refrigeration[J]. Adv Mater, 2009, 21(19): 1983–1987.

[118] [118] LE GOUPIL F, AXELSSON A K, DUNNE L J, et al. Anisotropy of the electrocaloric effect in lead-free relaxor ferroelectrics[J]. Adv Energy Mater, 2014, 4(9): 1301688.

          LE GOUPIL F, AXELSSON A K, DUNNE L J, et al. Anisotropy of the electrocaloric effect in lead-free relaxor ferroelectrics[J]. Adv Energy Mater, 2014, 4(9): 1301688.

[119] [119] LIU W, LI F, CHEN G H, et al. Comparative study of phase structure,dielectric properties and electrocaloric effect in novel high-entropy ceramics[J]. J Mater Sci, 2021, 56(33): 18417–18429.

          LIU W, LI F, CHEN G H, et al. Comparative study of phase structure,dielectric properties and electrocaloric effect in novel high-entropy ceramics[J]. J Mater Sci, 2021, 56(33): 18417–18429.

[120] [120] PU Y P, ZHANG Q W, LI R, et al. Dielectric properties and electrocaloric effect of high-entropy (Na0.2Bi0.2Ba0.2Sr0.2Ca0.2)TiO3 ceramic[J]. Appl Phys Lett, 2019, 115(22): 223901.

          PU Y P, ZHANG Q W, LI R, et al. Dielectric properties and electrocaloric effect of high-entropy (Na0.2Bi0.2Ba0.2Sr0.2Ca0.2)TiO3 ceramic[J]. Appl Phys Lett, 2019, 115(22): 223901.

[121] [121] WEI S Y, CHEN X, DONG G Z, et al. Large electrocaloric effect in two-step-SPS processed Pb(Sc0.25In0.25Nb0.25Ta0.25)O3 mediumentropy ceramics[J]. Ceram Int, 2022, 48(11): 15640–15646.

          WEI S Y, CHEN X, DONG G Z, et al. Large electrocaloric effect in two-step-SPS processed Pb(Sc0.25In0.25Nb0.25Ta0.25)O3 mediumentropy ceramics[J]. Ceram Int, 2022, 48(11): 15640–15646.

[122] [122] SHARMA Y, LEE M C, PITIKE K C, et al. High entropy oxide relaxor ferroelectrics[J]. ACS Appl Mater Interfaces, 2022, 14(9):11962–11970.

          SHARMA Y, LEE M C, PITIKE K C, et al. High entropy oxide relaxor ferroelectrics[J]. ACS Appl Mater Interfaces, 2022, 14(9):11962–11970.

[123] [123] SON Y, ZHU W L, TROLIER–MCKINSTRY S E. Electrocaloric effect of perovskite high entropy oxide films[J]. Adv Elect Materials,2022, 8(12): 2200352.

          SON Y, ZHU W L, TROLIER–MCKINSTRY S E. Electrocaloric effect of perovskite high entropy oxide films[J]. Adv Elect Materials,2022, 8(12): 2200352.

[124] [124] GRUVERMAN A, WU D, FAN H J, et al. Vortex ferroelectric domains[J]. J Phys: Condens Matter, 2008, 20(34): 342201.

          GRUVERMAN A, WU D, FAN H J, et al. Vortex ferroelectric domains[J]. J Phys: Condens Matter, 2008, 20(34): 342201.

[125] [125] HONG Z J, DAS S, NELSON C, et al. Vortex domain walls in ferroelectrics[J]. Nano Lett, 2021, 21(8): 3533–3539.

          HONG Z J, DAS S, NELSON C, et al. Vortex domain walls in ferroelectrics[J]. Nano Lett, 2021, 21(8): 3533–3539.

[126] [126] ZHANG H Y, SONG X J, CHEN X G, et al. Observation of vortex domains in a two-dimensional lead iodide perovskite ferroelectric[J].J Am Chem Soc, 2020, 142(10): 4925–4931.

          ZHANG H Y, SONG X J, CHEN X G, et al. Observation of vortex domains in a two-dimensional lead iodide perovskite ferroelectric[J].J Am Chem Soc, 2020, 142(10): 4925–4931.

[127] [127] DAS S, HONG Z, STOICA V A, et al. Local negative permittivity and topological phase transition in polar skyrmions[J]. Nat Mater,2021, 20(2): 194–201.

          DAS S, HONG Z, STOICA V A, et al. Local negative permittivity and topological phase transition in polar skyrmions[J]. Nat Mater,2021, 20(2): 194–201.

[128] [128] WANG Y J, FENG Y P, ZHU Y L, et al. Polar meron lattice in strained oxide ferroelectrics[J]. Nat Mater, 2020, 19(8): 881–886.

          WANG Y J, FENG Y P, ZHU Y L, et al. Polar meron lattice in strained oxide ferroelectrics[J]. Nat Mater, 2020, 19(8): 881–886.

[129] [129] QI H, CHEN L, DENG S Q, et al. High-entropy ferroelectric materials[J]. Nat Rev Mater, 2023, 8(6): 355–356.

          QI H, CHEN L, DENG S Q, et al. High-entropy ferroelectric materials[J]. Nat Rev Mater, 2023, 8(6): 355–356.

[130] [130] KAUFMANN K, MARYANOVSKY D, MELLOR W M, et al.Discovery of high-entropy ceramics via machine learning[J]. NPJ Comput Mater, 2020, 6: 42.

          KAUFMANN K, MARYANOVSKY D, MELLOR W M, et al.Discovery of high-entropy ceramics via machine learning[J]. NPJ Comput Mater, 2020, 6: 42.

[131] [131] WEN C, ZHANG Y, WANG C X, et al. Machine learning assisted design of high entropy alloys with desired property[J]. Acta Mater,2019, 170: 109–117.

          WEN C, ZHANG Y, WANG C X, et al. Machine learning assisted design of high entropy alloys with desired property[J]. Acta Mater,2019, 170: 109–117.

[132] [132] HUANG E W, LEE W J, SINGH S S, et al. Machine-learning and high-throughput studies for high-entropy materials[J]. Mater Sci EngR Rep, 2022, 147: 100645.

          HUANG E W, LEE W J, SINGH S S, et al. Machine-learning and high-throughput studies for high-entropy materials[J]. Mater Sci EngR Rep, 2022, 147: 100645.

[133] [133] LIU X L, ZHANG J X, PEI Z R. Machine learning for high-entropy alloys: Progress, challenges and opportunities[J]. Prog Mater Sci, 2023, 131: 101018.

          LIU X L, ZHANG J X, PEI Z R. Machine learning for high-entropy alloys: Progress, challenges and opportunities[J]. Prog Mater Sci, 2023, 131: 101018.

[134] [134] HE J J, YU C Y, HOU Y X, et al. Accelerated discovery of high-performance piezocatalyst in BaTiO3-based ceramics via machine learning[J]. Nano Energy, 2022, 97: 107218.

          HE J J, YU C Y, HOU Y X, et al. Accelerated discovery of high-performance piezocatalyst in BaTiO3-based ceramics via machine learning[J]. Nano Energy, 2022, 97: 107218.

[135] [135] KADIRVEL K, FRASER H L, WANG Y Z. Microstructural design via spinodal-mediated phase transformation pathways in high-entropy alloys (HEAs) using phase-field modelling[J]. Acta Mater, 2023, 243:118438.

          KADIRVEL K, FRASER H L, WANG Y Z. Microstructural design via spinodal-mediated phase transformation pathways in high-entropy alloys (HEAs) using phase-field modelling[J]. Acta Mater, 2023, 243:118438.

[136] [136] LI W X, YANG T N, LIU C S, et al. Optimizing piezoelectric nanocomposites by high-throughput phase-field simulation and machine learning[J]. Adv Sci, 2022, 9(13): e2105550.

          LI W X, YANG T N, LIU C S, et al. Optimizing piezoelectric nanocomposites by high-throughput phase-field simulation and machine learning[J]. Adv Sci, 2022, 9(13): e2105550.

[137] [137] WANG J, SHI S Q, CHEN L Q, et al. Phase-field simulations of ferroelectric/ferroelastic polarization switching[J]. Acta Mater, 2004,52(3): 749–764.

          WANG J, SHI S Q, CHEN L Q, et al. Phase-field simulations of ferroelectric/ferroelastic polarization switching[J]. Acta Mater, 2004,52(3): 749–764.