LaMoNbOthick films have been successfully prepared by using a tape casting technique. Partial stabilization of the high temperature cubic phase is revealed in Nb doped LaMoO(LMO) films. The sintering temperature is de...LaMoNbOthick films have been successfully prepared by using a tape casting technique. Partial stabilization of the high temperature cubic phase is revealed in Nb doped LaMoO(LMO) films. The sintering temperature is decreased to 925 ℃ as compared with that of 1150 ℃ in bulk ceramics. The grain exhibits an oxide ionic conductivity of 0.014 S cmat 603 ℃ for LaMoNbO, which is 39% higher than pure LMO. Additionally, the Nb doped LMO films present low grain boundary resistance showing the potential application as solid electrolytes.展开更多
ZnS has great potentials as an anode for lithium storage because of its high theoretical capacity and resource abundance;however,the large volume expansion accompanied with structural collapse and low conductivity of ...ZnS has great potentials as an anode for lithium storage because of its high theoretical capacity and resource abundance;however,the large volume expansion accompanied with structural collapse and low conductivity of ZnS cause severe capacity fading and inferior rate capability during lithium storage. Herein,0D-2 D ZnS nanodots/Ti_(3)C_(2)T_x MXene hybrids are prepared by anchoring ZnS nanodots on Ti_(3)C_(2)T_(x) MXene nanosheets through coordination modulation between MXene and MOF precursor(ZIF-8) followed with sulfidation. The MXene substratecoupled with the ZnS nanodots can synergistically accommodate volume variation of ZnS over charge–discharge to realize stable cyclability. As revealed by XPS characterizations and DFT calculations,the strong interfacial interaction between ZnS nanodots and MXene nanosheets can boost fast electron/lithium-ion transfer to achieve excellent electrochemical activity and kinetics for lithium storage. Thereby,the as-prepared ZnS nanodots/MXene hybrid exhibits a high capacity of 726.8 mAh g^(-1) at 30 mA g^(-1),superior cyclic stability(462.8 mAh g^(-1) after 1000 cycles at 0.5 A g^(-1)),and excellent rate performance. The present results provide new insights into the understanding of the lithium storage mechanism of ZnS and the revealing of the e ects of interfacial interaction on lithium storage performance enhancement.展开更多
The large-scale accumulation and pollution of solid mining waste is an urgent issue.Coal gangue is a prominent type of solid waste,and shows promise for use in high value-added products due to its content of many impo...The large-scale accumulation and pollution of solid mining waste is an urgent issue.Coal gangue is a prominent type of solid waste,and shows promise for use in high value-added products due to its content of many important compounds,including SiO_(2) and Al2O3.This study proposed the preparation of highly porous ceramics from coal gangue,coal slime,and coconut palm fibers.The ceramics were produced at a sintering temperature of 950℃ with a fiber content of 6 wt%,which led to the formation of porous ceramics with a porosity of 66.93%,volume density of 1.0329 g/cm^(3),compressive strength of 1.1025 MPa,and thermal conductivity is 0.3919 K(W/mk).A finite element model of the porous ceramics was established using the Abaqus module in ANSYS software,where the stress distribution and compressive strength were simulated.Further,the relationship between porosity and compressive strength was analyzed.The thermal properties of the porous ceramics were analyzed using the Fluent module,where the simulated changes in porosity under various sintering temperatures were consistent with the experimental data.The preparation of this highly porous ceramic from solid waste coal gangue shows promise for the minimizing the impact of waste gas and wastewater pollution in the future.展开更多
Single-phase Ba(Ti_(0.2)Zr_(0.2)Sn_(0.2)Hf_(0.2)Ce_(0.2))O_(3)(BTZSHC) high-entropy ceramics(HECs) with the perovskite structure were successfully prepared via the sol-gel method.The results reveal that the as-prepare...Single-phase Ba(Ti_(0.2)Zr_(0.2)Sn_(0.2)Hf_(0.2)Ce_(0.2))O_(3)(BTZSHC) high-entropy ceramics(HECs) with the perovskite structure were successfully prepared via the sol-gel method.The results reveal that the as-prepared ceramics exhibit a single cubic phase belonging to the Pm3 m space group.The high entropy is the driving force of the formation of single-phase ceramics.A larger entropy(ΔS_(mix)) and a negative enthalpy(ΔH_(mix)) are conducive to the formation of single-phase compounds.Herein,ΔS_(mix)=0.323 R mole-1andΔH_(mix)=43.88 kJ/mol.The sluggish-diffusion effect ensures the thermal stability of high-entropy systems.Dielectric measurements reveal that the as-prepared BTZSHC high-entropy ceramics are relaxor ferroelectrics,and the degree of relaxor(γ) is 1.9.The relaxor behavior of the as-prepared ceramics can be ascribed to the relaxation and thermal evolution of their polar units(PUs).The findings of this work provide a theoretical basis and technical support for the preparation of single-phase high-entropy ceramics.展开更多
The large accumulation of coal gangue,a common industrial solid waste,causes severe environmental problems,and green development strategies are required to transform this waste into high-value-added products.In this s...The large accumulation of coal gangue,a common industrial solid waste,causes severe environmental problems,and green development strategies are required to transform this waste into high-value-added products.In this study,low-cost ceramsites adsorbents were prepared from waste gangue,silt coal,and peanut shells and applied to remove the organic dye methylene blue from wastewater.We investigated the microstructure of ceramsites and the effects of the sintering atmosphere,sintering temperature,and solution pH on their adsorption performance.The ceramsites sintered at 800℃under a nitrogen atmosphere exhibited the largest three-dimensional-interconnected hierarchical porous structure among the prepared ceramsites;further,it exhibited the highest methylene blue adsorption performance,with an adsorption capacity of 0.954 mg·g^(−1),adsorption efficiency of over 95%,and adsorption equilibrium time of 1 h at a solution pH of 9.The removal efficiency remained greater than 75%after five adsorption cycles.The adsorption kinetics data were analyzed using various models,including the pseudosecond-order kinetic model and Langmuir equation,and the adsorption was attributed to electrostatic interactions between the dyes and ceramsites,n-interactions,and hydrogen bonds.The prepared coal gangue ceramsites exhibited excellent adsorption capacities,removal rates,and cyclic stabilities,demonstrating their promising application prospects for the comprehensive utilization of solid waste and for wastewater treatment.展开更多
Ionic polymer-metal composites(IPMCs)constitute a new type of artificial muscle material that is commonly used in bionic soft robots and medical devices because of its small driving voltage and considerable deformatio...Ionic polymer-metal composites(IPMCs)constitute a new type of artificial muscle material that is commonly used in bionic soft robots and medical devices because of its small driving voltage and considerable deformation.However,IPMCs are limited by performance issues such as low output force and small operating time away from water.Silicon dioxide sulfonated graphene(SiO_(2)-SGO)particles are often used to improve the performance of polymer membranes because of their hydrophilicity and high chemical stability.Reported here is the addition of SiO_(2)-SGO particles prepared by in situ hydrolysis to perfluorosulfonic acid in order to improve the IPMC properties.Also,a predictive model was constructed based on a backpropagation neural network,with the SiO_(2)-SGO doping amount and the IPMC excitation voltage in the input layer and the driving displacement in the output layer.The results show that the IPMC prepared with 1.0 wt.%doping content performed the best,with a maximum output displacement of 47.7 mm.The correlation coefficient(R2)was 0.9842 and the mean square error was 0.00037073,which show that the predictive model has high predictive accuracy and is suitable for predicting the performance of the SiO_(2)-SGO-modified IPMC.展开更多
The development of high-performance nearinfrared(NIR)absorbing electron acceptors is a major challenge in achieving high short-circuit current density(JSC)to increase power conversion efficiency(PCE)of organic solar c...The development of high-performance nearinfrared(NIR)absorbing electron acceptors is a major challenge in achieving high short-circuit current density(JSC)to increase power conversion efficiency(PCE)of organic solar cells(OSCs).Herein,three new multi-heteroatomized Y-series acceptors(bi-asy-Y-Br,bi-asy-Y-FBr,and bi-asy-Y-FBrF)were developed by combining dual-asymmetric selenium-fused core and brominated end-groups with different numbers of fluorine substitutions.With gradually increasing fluorination,three acceptors exhibit red-shift absorption.Among them,biasy-Y-FBrF presents planar molecular geometry,the maximum average electrostatic potential,and the minimum molecular dipole moment,which are conducive to intramolecular packing and charge transport.Moreover,D18:bi-asy-Y-FBrF active layer presents higher crystallinity,more suitable phase separation,and reduced charge recombination compared to D18:bi-asy-Y-Br and D18:bi-asy-Y-FBr blends.Consequently,among theses binary OSCs,D18:bi-asy-Y-FBrF device achieves a higher PCE of 15.74% with an enhanced JSC of 26.28 mA cm^(-2),while D18:bi-asy-Y-Br device obtains a moderate PCE of 15.04% with the highest open-circuit voltage(VOC)of 0.926 V.Inspired by its high VOC and complementary absorption with NIR-absorbing BTP-eC9 as acceptor,bi-asy-Y-Br is introduced into binary D18:BTP-eC9 to construct ternary OSCs,achieving a further boosted PCE of 19.12%,which is among the top values for the reported green solvent processed OSCs.展开更多
Defect engineering enables the efficient management of electromagnetic parameters and the enhancement of electromagnetic wave(EMW)absorption.In this study,(Fe_(1−x)Mn_(x))_(2)AlB_(2) transition metal boride(MAB)phases...Defect engineering enables the efficient management of electromagnetic parameters and the enhancement of electromagnetic wave(EMW)absorption.In this study,(Fe_(1−x)Mn_(x))_(2)AlB_(2) transition metal boride(MAB)phases with a layered structure were prepared via Joule heating-driven ultrafast synthesis,and their EMW absorption properties were investigated.The experimental results demonstrate that the incorporation of Mn atoms at the M site can effectively modulate the impedance matching and EMW absorption properties of the material through the introduction of defects and lattice distortions.Notably,(Fe_(0.3)Mn_(0.7))_(2)AlB_(2) exhibits a reflection loss as high as−47.8 dB at 12.24 GHz,with a maximum effective absorption bandwidth of 4.16 GHz(10.24-14.40 GHz)at an ultrasmall thickness of 1.5 mm.This study provides a promising avenue for the development of excellent microwave-absorbing materials,which are essential for meeting the evolving requirements of advanced electronics.Additionally,this work offers a paradigm for enhancing other properties of MAB phases through defect engineering.展开更多
Novel A-site deficient(1-x-y)Bi_(0.5)Na_(0.5)TiO_(3-x)BaTiO_(3-y)Bi_(0.2)Sr_(0.7)TiO_(3)lead-free relaxor ferroelectrics have been explored for energy storage property.Particularly slim polarization hysteresis(P-E)loo...Novel A-site deficient(1-x-y)Bi_(0.5)Na_(0.5)TiO_(3-x)BaTiO_(3-y)Bi_(0.2)Sr_(0.7)TiO_(3)lead-free relaxor ferroelectrics have been explored for energy storage property.Particularly slim polarization hysteresis(P-E)loops are observed in 0.655Bi_(0.5)Na_(0.5)TiO_(3)-0.065BaTiO_(3)-0.28Bi_(0.2)Sr_(0.7)□_(0.1)TiO_(3)(6.5BNBT-BST)at ambient temperature resulting in a giant recoverable energy density(W_(rec)=1.5 J cm^(-3))and extremely high efficiency(η=90%)at 100 kV cm^(-1),which are closed related to the track of P-E loops.As the addition of Bi_(0.2)Sr_(0.7)TiO_(3)(BST)content,the ergodic relaxor phase becomes dominant with dynamic polar nanoregions attributed to the absence of ferroelectric domain in the relaxor phase.Furthermore,the recoverable energy density exhibits small variation in elevated temperature where the depressed polarization is compensated by almost hysteresis free loops(ηup to 97%).The achievement of these characteristics in P-E loops provides that Bi_(0.2)Sr_(0.7)TiO_(3)tailoring by A-site vacancies is a potential route when designing new relaxor ferroelectrics for energy-storage applications.展开更多
基金supported by the National Natural Science Foundation(51602252,51372197)the Key Innovation Team of Shaanxi Province(2014KCT-04)+1 种基金the Major International Joint Research Program of Shaanxi Province(2012KW-10)the Outstanding Youth Science Fund of Xi’an University of Science and Technology
文摘LaMoNbOthick films have been successfully prepared by using a tape casting technique. Partial stabilization of the high temperature cubic phase is revealed in Nb doped LaMoO(LMO) films. The sintering temperature is decreased to 925 ℃ as compared with that of 1150 ℃ in bulk ceramics. The grain exhibits an oxide ionic conductivity of 0.014 S cmat 603 ℃ for LaMoNbO, which is 39% higher than pure LMO. Additionally, the Nb doped LMO films present low grain boundary resistance showing the potential application as solid electrolytes.
基金supported by the National Natural Science Foundation of China (21805011,51902251,52072021,and U2004212)the State Key Laboratory of Organic-Inorganic Composites (oic-202101010)+1 种基金the Natural Science Foundation of Shaanxi Provincial Department of Education (20JK0753)the Provincial Joint Fund of Shaanxi (2021JLM-28)。
文摘ZnS has great potentials as an anode for lithium storage because of its high theoretical capacity and resource abundance;however,the large volume expansion accompanied with structural collapse and low conductivity of ZnS cause severe capacity fading and inferior rate capability during lithium storage. Herein,0D-2 D ZnS nanodots/Ti_(3)C_(2)T_x MXene hybrids are prepared by anchoring ZnS nanodots on Ti_(3)C_(2)T_(x) MXene nanosheets through coordination modulation between MXene and MOF precursor(ZIF-8) followed with sulfidation. The MXene substratecoupled with the ZnS nanodots can synergistically accommodate volume variation of ZnS over charge–discharge to realize stable cyclability. As revealed by XPS characterizations and DFT calculations,the strong interfacial interaction between ZnS nanodots and MXene nanosheets can boost fast electron/lithium-ion transfer to achieve excellent electrochemical activity and kinetics for lithium storage. Thereby,the as-prepared ZnS nanodots/MXene hybrid exhibits a high capacity of 726.8 mAh g^(-1) at 30 mA g^(-1),superior cyclic stability(462.8 mAh g^(-1) after 1000 cycles at 0.5 A g^(-1)),and excellent rate performance. The present results provide new insights into the understanding of the lithium storage mechanism of ZnS and the revealing of the e ects of interfacial interaction on lithium storage performance enhancement.
基金National Natural Science Foundation of China under Grant No.(51372197)Key Innovation Team of Shaanxi Province under Grant No.(2014KCT-04)Provincial Joint Fund of Shaanxi(2021JLM-28).
文摘The large-scale accumulation and pollution of solid mining waste is an urgent issue.Coal gangue is a prominent type of solid waste,and shows promise for use in high value-added products due to its content of many important compounds,including SiO_(2) and Al2O3.This study proposed the preparation of highly porous ceramics from coal gangue,coal slime,and coconut palm fibers.The ceramics were produced at a sintering temperature of 950℃ with a fiber content of 6 wt%,which led to the formation of porous ceramics with a porosity of 66.93%,volume density of 1.0329 g/cm^(3),compressive strength of 1.1025 MPa,and thermal conductivity is 0.3919 K(W/mk).A finite element model of the porous ceramics was established using the Abaqus module in ANSYS software,where the stress distribution and compressive strength were simulated.Further,the relationship between porosity and compressive strength was analyzed.The thermal properties of the porous ceramics were analyzed using the Fluent module,where the simulated changes in porosity under various sintering temperatures were consistent with the experimental data.The preparation of this highly porous ceramic from solid waste coal gangue shows promise for the minimizing the impact of waste gas and wastewater pollution in the future.
基金financially supported by the National Natural Science Foundation of China (Nos.52102144,52172099)the Provincial Joint Fund of Shaanxi (No.2021JLM-28)+1 种基金the Natural Science Basic Research Plan in Shaanxi Province of China (No.2022JM-255)the Scientific Research Plan Projects of Shaanxi Education Department (No.19JK0525)。
文摘Single-phase Ba(Ti_(0.2)Zr_(0.2)Sn_(0.2)Hf_(0.2)Ce_(0.2))O_(3)(BTZSHC) high-entropy ceramics(HECs) with the perovskite structure were successfully prepared via the sol-gel method.The results reveal that the as-prepared ceramics exhibit a single cubic phase belonging to the Pm3 m space group.The high entropy is the driving force of the formation of single-phase ceramics.A larger entropy(ΔS_(mix)) and a negative enthalpy(ΔH_(mix)) are conducive to the formation of single-phase compounds.Herein,ΔS_(mix)=0.323 R mole-1andΔH_(mix)=43.88 kJ/mol.The sluggish-diffusion effect ensures the thermal stability of high-entropy systems.Dielectric measurements reveal that the as-prepared BTZSHC high-entropy ceramics are relaxor ferroelectrics,and the degree of relaxor(γ) is 1.9.The relaxor behavior of the as-prepared ceramics can be ascribed to the relaxation and thermal evolution of their polar units(PUs).The findings of this work provide a theoretical basis and technical support for the preparation of single-phase high-entropy ceramics.
基金supported by the Natural Science Foundation of China under Grant(No.52172099)the Provincial Joint Fund of Shaanxi(2021JLM-28).
文摘The large accumulation of coal gangue,a common industrial solid waste,causes severe environmental problems,and green development strategies are required to transform this waste into high-value-added products.In this study,low-cost ceramsites adsorbents were prepared from waste gangue,silt coal,and peanut shells and applied to remove the organic dye methylene blue from wastewater.We investigated the microstructure of ceramsites and the effects of the sintering atmosphere,sintering temperature,and solution pH on their adsorption performance.The ceramsites sintered at 800℃under a nitrogen atmosphere exhibited the largest three-dimensional-interconnected hierarchical porous structure among the prepared ceramsites;further,it exhibited the highest methylene blue adsorption performance,with an adsorption capacity of 0.954 mg·g^(−1),adsorption efficiency of over 95%,and adsorption equilibrium time of 1 h at a solution pH of 9.The removal efficiency remained greater than 75%after five adsorption cycles.The adsorption kinetics data were analyzed using various models,including the pseudosecond-order kinetic model and Langmuir equation,and the adsorption was attributed to electrostatic interactions between the dyes and ceramsites,n-interactions,and hydrogen bonds.The prepared coal gangue ceramsites exhibited excellent adsorption capacities,removal rates,and cyclic stabilities,demonstrating their promising application prospects for the comprehensive utilization of solid waste and for wastewater treatment.
基金funded by the Digital workshop dynamic Reconstruction modeling Technology(Grant No.2020YFB1710701)the National Natural Science Foundation of China(Grant No.52172099)the Provincial Joint Fund of Shaanxi(Grant No.2021JLM-28).
文摘Ionic polymer-metal composites(IPMCs)constitute a new type of artificial muscle material that is commonly used in bionic soft robots and medical devices because of its small driving voltage and considerable deformation.However,IPMCs are limited by performance issues such as low output force and small operating time away from water.Silicon dioxide sulfonated graphene(SiO_(2)-SGO)particles are often used to improve the performance of polymer membranes because of their hydrophilicity and high chemical stability.Reported here is the addition of SiO_(2)-SGO particles prepared by in situ hydrolysis to perfluorosulfonic acid in order to improve the IPMC properties.Also,a predictive model was constructed based on a backpropagation neural network,with the SiO_(2)-SGO doping amount and the IPMC excitation voltage in the input layer and the driving displacement in the output layer.The results show that the IPMC prepared with 1.0 wt.%doping content performed the best,with a maximum output displacement of 47.7 mm.The correlation coefficient(R2)was 0.9842 and the mean square error was 0.00037073,which show that the predictive model has high predictive accuracy and is suitable for predicting the performance of the SiO_(2)-SGO-modified IPMC.
基金supported by the National Key Research and Development Program of China(2022YFE0132400)the National Natural Science Foundation of China(NSFC)(22209131 and 22405204)+6 种基金the Key Scientific and Technological Innovation Team Project of Shaanxi Province(2020TD-002)the 111 project 2.0(BP0618008)the Postdoctoral Innovation Talents Support Program(BX20230285)the Science and Technology Program of Shaanxi Province(2023-JC-QN-0448)the Outstanding Youth Science and Technology Fund Project of Xi’an University of Science and Technology(8159922001)the Open Fund of Jiangsu Engineering Laboratory of Light-Electricity-Heat Energy-Converting Materials and Applications(Changzhou University)(GDRGCS2023002)supported by the Director,Office of Science,Office of Basic Energy Sciences of the U.S.Department of Energy under Contract No.DE-AC02-05CH11231.
文摘The development of high-performance nearinfrared(NIR)absorbing electron acceptors is a major challenge in achieving high short-circuit current density(JSC)to increase power conversion efficiency(PCE)of organic solar cells(OSCs).Herein,three new multi-heteroatomized Y-series acceptors(bi-asy-Y-Br,bi-asy-Y-FBr,and bi-asy-Y-FBrF)were developed by combining dual-asymmetric selenium-fused core and brominated end-groups with different numbers of fluorine substitutions.With gradually increasing fluorination,three acceptors exhibit red-shift absorption.Among them,biasy-Y-FBrF presents planar molecular geometry,the maximum average electrostatic potential,and the minimum molecular dipole moment,which are conducive to intramolecular packing and charge transport.Moreover,D18:bi-asy-Y-FBrF active layer presents higher crystallinity,more suitable phase separation,and reduced charge recombination compared to D18:bi-asy-Y-Br and D18:bi-asy-Y-FBr blends.Consequently,among theses binary OSCs,D18:bi-asy-Y-FBrF device achieves a higher PCE of 15.74% with an enhanced JSC of 26.28 mA cm^(-2),while D18:bi-asy-Y-Br device obtains a moderate PCE of 15.04% with the highest open-circuit voltage(VOC)of 0.926 V.Inspired by its high VOC and complementary absorption with NIR-absorbing BTP-eC9 as acceptor,bi-asy-Y-Br is introduced into binary D18:BTP-eC9 to construct ternary OSCs,achieving a further boosted PCE of 19.12%,which is among the top values for the reported green solvent processed OSCs.
文摘Defect engineering enables the efficient management of electromagnetic parameters and the enhancement of electromagnetic wave(EMW)absorption.In this study,(Fe_(1−x)Mn_(x))_(2)AlB_(2) transition metal boride(MAB)phases with a layered structure were prepared via Joule heating-driven ultrafast synthesis,and their EMW absorption properties were investigated.The experimental results demonstrate that the incorporation of Mn atoms at the M site can effectively modulate the impedance matching and EMW absorption properties of the material through the introduction of defects and lattice distortions.Notably,(Fe_(0.3)Mn_(0.7))_(2)AlB_(2) exhibits a reflection loss as high as−47.8 dB at 12.24 GHz,with a maximum effective absorption bandwidth of 4.16 GHz(10.24-14.40 GHz)at an ultrasmall thickness of 1.5 mm.This study provides a promising avenue for the development of excellent microwave-absorbing materials,which are essential for meeting the evolving requirements of advanced electronics.Additionally,this work offers a paradigm for enhancing other properties of MAB phases through defect engineering.
基金This work was supported by the National Natural Science Foundation(51602252,51702249,51372197 and 51672092)the Key Innovation Team of Shaanxi Province(2014KCT-04)+4 种基金the fund of the State Key Laboratory of Solidification Processing in NWPU(SKLSP201624)the China Postdoctoral Science Foundation(2017M613065)the Shaanxi Province Science Foundation(2017JQ5072)the Outstanding Youth Science Fund of Xi'an University of Science and Technology(2018YQ2-11)the Shanghai talent development fund(2017128).
文摘Novel A-site deficient(1-x-y)Bi_(0.5)Na_(0.5)TiO_(3-x)BaTiO_(3-y)Bi_(0.2)Sr_(0.7)TiO_(3)lead-free relaxor ferroelectrics have been explored for energy storage property.Particularly slim polarization hysteresis(P-E)loops are observed in 0.655Bi_(0.5)Na_(0.5)TiO_(3)-0.065BaTiO_(3)-0.28Bi_(0.2)Sr_(0.7)□_(0.1)TiO_(3)(6.5BNBT-BST)at ambient temperature resulting in a giant recoverable energy density(W_(rec)=1.5 J cm^(-3))and extremely high efficiency(η=90%)at 100 kV cm^(-1),which are closed related to the track of P-E loops.As the addition of Bi_(0.2)Sr_(0.7)TiO_(3)(BST)content,the ergodic relaxor phase becomes dominant with dynamic polar nanoregions attributed to the absence of ferroelectric domain in the relaxor phase.Furthermore,the recoverable energy density exhibits small variation in elevated temperature where the depressed polarization is compensated by almost hysteresis free loops(ηup to 97%).The achievement of these characteristics in P-E loops provides that Bi_(0.2)Sr_(0.7)TiO_(3)tailoring by A-site vacancies is a potential route when designing new relaxor ferroelectrics for energy-storage applications.
