AgNbO_(3)(AN)and modified AgNbO_(3) have been extensively investigated as promising lead-free antiferroelectric(AFE)energy storage materials.Previous studies have focused mainly on the use of an ion dopant at the A/B ...AgNbO_(3)(AN)and modified AgNbO_(3) have been extensively investigated as promising lead-free antiferroelectric(AFE)energy storage materials.Previous studies have focused mainly on the use of an ion dopant at the A/B site to obtain a stabilized AFE phase;however,simultaneous improvements in the recoverable energy storage density(Wrec)and efficiency(n)are stll difficult to realize.Herein,we innovatively constructed a AgNbO_(3)-NaNbO_(3)-(Sr_(0.7)Bi_(0.2))TiO_(3)(AN-NN-SBT)ternary solid solution to achieve a relaxor AFE in AgNbO_(3)-based materials.The coexistence of antiferroelectric(M3)and paraelectric(O)phases in 0.8(0.7AgNbO_(3)-0.3NaNbO_(3))-0.2(Sro.7Bio.2)TiO_(3) confirms the successful realization of a relaxor AFE,attributed to multiple ion occupation at the A/B sites.Consequently,a high Wrec of 7.53 J.cm^(-3) and n of 74.0% are acquired,together with superior stability against various temperatures,frequencies,and cycling numbers.Furthermore,a high power density(298.7 MW·cm^(-3))and fast discharge speed(41.4 ns)are also demonstrated for the AgNbO_(3)-based relaxor AFE.This work presents a promising energy storage AgNbO_(3)-based ternary solid solution and proposes a novel strategy for AgNbO_(3)-based energy storage via the design of relaxor AFE materials.展开更多
A triboelectric nanogenerator(TENG)is a highly potential green energy harvesting technology to power small-scale electronic devices.Enhancing the overall electricity production capacity of TENGs is a primary concern f...A triboelectric nanogenerator(TENG)is a highly potential green energy harvesting technology to power small-scale electronic devices.Enhancing the overall electricity production capacity of TENGs is a primary concern for their utilization as an electricity generator in day-to-day life.Herein,we proposed a lead-free silver niobate(AgNbO_(3)(ANb))microparticles(MPs)-embedded polydimethylsiloxane(PDMS)composite film-based clip-like hybrid nanogenerator(HNG)device,producing an enhanced electrical output from the applied mechanical movements.The ANb MPs with a high dielectric constant were initially synthesized and embedded inside the PDMS polymer matrix.Various HNGs were fabricated utilizing ANb MPs/PDMS composite films/aluminum tape as negative/positive triboelectric films,respectively and operated in contact-separation mode.The electrical output from them was comparatively analyzed to investigate an optimum concentration of the ANb MPs inside the PDMS film.The robust HNG with 5 wt%ANb MPs/PDMS composite film produced the highest electrical output with promising stability.Thereafter,three similar optimized HNGs were fabricated and integrated within a 3D-printed clip-like structure and the electrical output was thoroughly evaluated while combining multiple HNGs as well as from each independent HNG.The clip-like HNG device exhibited an electrical output of 340 V and 20μA that can be further utilized to charge various capacitors and power portable electronics.Owing to the high resilience structure of the clip-like HNG device,it was also demonstrated to harvest biomechanical energy produced by human movements into electricity.The mechanical energy harvesting when the clip-like HNG device was attached to the accelerator pedal of the car and the pedal of a musical piano was successfully demonstrated.展开更多
Due to its lead-free composition and a unique double polarization hysteresis loop with a large maximum polarization(Pmax)and a small remnant polarization(Pr),AgNbO_(3)-based antiferroelectrics(AFEs)have attracted exte...Due to its lead-free composition and a unique double polarization hysteresis loop with a large maximum polarization(Pmax)and a small remnant polarization(Pr),AgNbO_(3)-based antiferroelectrics(AFEs)have attracted extensive research interest for electric energy storage applications.However,a low dielectric breakdown field(Eb)limits an energy density and its further development.In this work,a highly efficient method was proposed to fabricate high-energy-density Ag(Nb,Ta)O_(3) capacitor films on Si substrates,using a two-step process combining radio frequency(RF)-magnetron sputtering at 450℃and post-deposition rapid thermal annealing(RTA).The RTA process at 700℃led to sufficient crystallization of nanograins in the film,hindering their lateral growth by employing short annealing time of 5 min.The obtained Ag(Nb,Ta)O_(3) films showed an average grain size(D)of~14 nm(obtained by Debye-Scherrer formula)and a slender room temperature(RT)polarization-electric field(P-E)loop(Pr≈3.8 mC·cm^(−2) and P_(max)≈38 mC·cm^(−2) under an electric field of~3.3 MV·cm^(−1)),the P-E loop corresponding to a high recoverable energy density(W_(rec))of~46.4 J·cm^(−3) and an energy efficiency(η)of~80.3%.Additionally,by analyzing temperature-dependent dielectric property of the film,a significant downshift of the diffused phase transition temperature(T_(M2-M3))was revealed,which indicated the existence of a stable relaxor-like AFE phase near the RT.The downshift of the T_(M2-M3) could be attributed to a nanograin size and residual tensile strain of the film,and it led to excellent temperature stability(20-240℃)of the energy storage performance of the film.Our results indicate that the Ag(Nb,Ta)O_(3) film is a promising candidate for electrical energy storage applications.展开更多
Antiferroelectric(AFE)materials are promising for the applications in advanced high-power electric and electronic devices.Among them,AgNbO_(3)(AN)-based ceramics have gained considerable attention due to their excelle...Antiferroelectric(AFE)materials are promising for the applications in advanced high-power electric and electronic devices.Among them,AgNbO_(3)(AN)-based ceramics have gained considerable attention due to their excellent energy storage performance.Herein,multiscale synergistic modulation is proposed to improve the energy storage performance of AN-based materials,whereby the multilayer structure is employed to improve the breakdown strength(Eb),and Sm/Ta doping is utilized to enhance the AFE stability.As a result,ultrahigh recoverable energy storage density(Wrec)up to 15.0 J·cm^(-3) and energy efficiency of 82.8%are obtained at 1500 kV·cm^(-3) in Sm/Ta co-doped AN multilayer ceramic capacitor(MLCC),which are superior to those of the state-of-the-art AN-based ceramic capacitor.Moreover,the discharge energy density(Wa)in direct-current charge-discharge performance reaches 9.1 J·cm^(-3),which is superior to that of the reported lead-free energy storage systems.The synergistic design of composition and multilayer structure provides an applicable method to optimize the energy storage performance in all dielectric energy storage systems.展开更多
Antiferroelectric materials are promising candidates for energy-storage applications due to their double hysteresis loops,which can deliver high power density.Among the antiferroelectric materials,AgNbO_(3)is proved a...Antiferroelectric materials are promising candidates for energy-storage applications due to their double hysteresis loops,which can deliver high power density.Among the antiferroelectric materials,AgNbO_(3)is proved attractive due to its environmental-friendliness and high potential for achieving excellent energy storage performance.However,the recoverable energy storage density of AgNbO_(3)ceramics is limited by their relatively low breakdown strength.Herein,the breakdown strength of the pure AgNbO_(3)ceramics prepared using the tape casting method is enhanced to 307 kV·cm^(-1),which is,to the best of our knowledge,among the highest values reported for pure AgNbO-3bulk ceramics.The high breakdown strength may be due to its dense microstructure and good crystallinity obtained by the tape casting method and the optimized sintering temperature.Owing to its enhanced breakdown strength,AgNbO_(3)ceramics show high recoverable energy storage density of 2.8 J·cm^(-3).These results have led to the development of lead-free antiferroelectric materials and devices with high energy storage density.展开更多
Lead-free antiferroelectric ceramics with high energy storage performance show great potential in pulsed power capacitors.However,poor breakdown strength and antiferroelectric stability are the two main drawbacks that...Lead-free antiferroelectric ceramics with high energy storage performance show great potential in pulsed power capacitors.However,poor breakdown strength and antiferroelectric stability are the two main drawbacks that limit the energy storage performance of antiferroelectric ceramics.Herein,highquality(Ag_(1-x)Na_(x))(Nb_(1-x)Ta_(x))O_(3)ceramics were prepared by the tape casting process.The breakdown strength was greatly improved as a result of the high density and fine grains,while the antiferroelectric stability was enhanced owning to the M2 phase.Benefiting from the synergistic improvement in breakdown strength and antiferroelectric stability,(Ag_(0.80)Na_(0.20))(Nb_(0.80)Ta_(0.20))O_(3)ceramic reveals a benign energy storage performance of W_(rec)=5.8 J/cm^(3)and h=61.7%with good temperature stability,frequency stability and cycling reliability.It is also found that the high applied electric field can promote the M2-M3 phase transition,which may provide ideas to improve the thermal stability of the energy storage performance in AgNbO_(3)-based ceramics.展开更多
It is crucial to discover lead-free materials with ultrahigh recoverable energy density(Wrec)that can be employed in future pulse power capacitors.In this work,a high Wrec of 4.51 J/cm^(3) was successfully obtained in...It is crucial to discover lead-free materials with ultrahigh recoverable energy density(Wrec)that can be employed in future pulse power capacitors.In this work,a high Wrec of 4.51 J/cm^(3) was successfully obtained in lead-free Nd-doped AgNb_(0.8)Ta_(0.2)O_(3) antiferroelectric ceramics at an applied electric field of 290 kV/cm.It is discovered that Nd doping paired with Nb-site vacancies could stabilize the antiferroelectric phase by lowering the temperatures of the M1-M2 and M2-M3 phase transitions,which leads to higher energy storage efficiency.Furthermore,Nd and Ta co-doping will contribute to the electrical homogeneity and low electrical conductivity,resulting in large breakdown strengths.Aliovalent doping in Ag-site with Nb-site vacancies serves as a novel strategy for the construction of AgNbO_(3)-based ceramics with excellent energy storage performance.展开更多
AgNbO_(3)based antiferroelectric(AFE)ceramics have large maximum polarization and low remanent polarization,and thus are important candidates for fabricating dielectric capacitors.However,their energy storage performa...AgNbO_(3)based antiferroelectric(AFE)ceramics have large maximum polarization and low remanent polarization,and thus are important candidates for fabricating dielectric capacitors.However,their energy storage performances have been still large difference with those of lead-based AFEs because of their room-temperature ferrielectric(FIE)behavior.In this study,novel La^(3+)and Ta^(5+)co-substituted AgNbO_(3)ceramics are designed and developed.The introduction of La^(3+)and Ta^(5+)decreases the tolerance factor,reduces the polarizability of B-site cations and increases local structure heterogeneity of AgNbO_(3),which enhance AFE phase stability and refine polarization-electric field(PeE)loops.Besides,adding La^(3+)and Ta^(5+)into AgNbO_(3)ceramics causes the decrease of the grain sizes and the increase of the band gap,which contribute to increased Eb.As a consequence,a high recoverable energy density of 6.79 J/cm3 and large efficiency of 82.1%,which exceed those of many recently reported AgNbO_(3)based ceramics in terms of overall energy storage properties,are obtained in(Ag0.88La0.04)(Nb0.96Ta0.04)O_(3)ceramics.Furthermore,the discharge properties of the ceramic with discharge time of 16 ns and power density of 145.03 MW/cm3 outperform those of many lead-free dielectric ceramics.展开更多
Antiferroelectric materials with double hysteresis loops are attractive for energy storage applications,which are becoming increasingly important for power electronics nowadays.Among them,AgNbO_(3) based lead-free cer...Antiferroelectric materials with double hysteresis loops are attractive for energy storage applications,which are becoming increasingly important for power electronics nowadays.Among them,AgNbO_(3) based lead-free ceramics have attracted intensive interest as one of promising environmental-friendly candidates.However,most of the AgNbO_(3) based ceramics suffers from low dielectric breakdown strength(Eb).The limitation of low Eb is broken to some extent in this work.Here,AgNbO_(3) epitaxial films were fabricated by pulsed laser deposition,which possess high Eb of 624 kV/cm.The(001)AgNbO_(3) epitaxial film reveals typical antiferroelectric hysteresis loops when the applied electric fields are over 300 kV/cm.A recoverable energy density of 5.8 J/cm^(3) and an energy efficiency of 55.8%are obtained at 600 kV/cm,which demonstrates the great promise of the AgNbO_(3) film for energy storage applications.展开更多
The solid-phase photocataKtic degradation of polyvinyl chloride(PVC)plastic with AgNbO_(3)/Fe_(2)O_(3) is studied under visible-light irradiation.The PVC-(AgNbO_(3)/Fe_(2)O_(3))samples are characterized by X-ray photo...The solid-phase photocataKtic degradation of polyvinyl chloride(PVC)plastic with AgNbO_(3)/Fe_(2)O_(3) is studied under visible-light irradiation.The PVC-(AgNbO_(3)/Fe_(2)O_(3))samples are characterized by X-ray photoelectron spectroscope(XPS),scanning electron microscope(SEM),gas chromatography(GC),and UV-vis diffusion reflectance spectra(UV-vis DRS).The photocatalytic properties of PVC-(AgNbO_(3)/Fe_(2)O_(3))samples are systematically investigated.More amounts of generated CO2,greater texture change and higher weight loss rate were exhibited in the system of PVC-(AgNbO_(3)/Fe_(2)O_(3))than pure PVC film.The weight loss rate is ten times higher than that of pure PVC film,which reaches to 46.53%with optimum amount of O.5wt% Fe_(2)O_(3).Active radicals generate primarily on the surface of Fe_(2)O_(3) particles,which cause composite plastic decomposition on the PVC-(AgNbO_(3)/Fe_(2)O_(3))interface and extend into polymer interor.The study provides a new promising way to degrade the plastic waste under visible-light.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.12204503 and U2002217)the Key Research Program of the Chinese Academy of Sciences(No.ZDRW-CN-2021-3-1-18)+2 种基金the Shanghai Pujiang Program(No.22PJD085)the Natural Science Foundation of Shanghai(No.23ZR1472400)the Young Elite Scientists Sponsorship Program by the China Association for Science and Technology(No.YESS20210265).
文摘AgNbO_(3)(AN)and modified AgNbO_(3) have been extensively investigated as promising lead-free antiferroelectric(AFE)energy storage materials.Previous studies have focused mainly on the use of an ion dopant at the A/B site to obtain a stabilized AFE phase;however,simultaneous improvements in the recoverable energy storage density(Wrec)and efficiency(n)are stll difficult to realize.Herein,we innovatively constructed a AgNbO_(3)-NaNbO_(3)-(Sr_(0.7)Bi_(0.2))TiO_(3)(AN-NN-SBT)ternary solid solution to achieve a relaxor AFE in AgNbO_(3)-based materials.The coexistence of antiferroelectric(M3)and paraelectric(O)phases in 0.8(0.7AgNbO_(3)-0.3NaNbO_(3))-0.2(Sro.7Bio.2)TiO_(3) confirms the successful realization of a relaxor AFE,attributed to multiple ion occupation at the A/B sites.Consequently,a high Wrec of 7.53 J.cm^(-3) and n of 74.0% are acquired,together with superior stability against various temperatures,frequencies,and cycling numbers.Furthermore,a high power density(298.7 MW·cm^(-3))and fast discharge speed(41.4 ns)are also demonstrated for the AgNbO_(3)-based relaxor AFE.This work presents a promising energy storage AgNbO_(3)-based ternary solid solution and proposes a novel strategy for AgNbO_(3)-based energy storage via the design of relaxor AFE materials.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIP)(No.2018R1A6A1A03025708 and No.2020M3H2A1076786).
文摘A triboelectric nanogenerator(TENG)is a highly potential green energy harvesting technology to power small-scale electronic devices.Enhancing the overall electricity production capacity of TENGs is a primary concern for their utilization as an electricity generator in day-to-day life.Herein,we proposed a lead-free silver niobate(AgNbO_(3)(ANb))microparticles(MPs)-embedded polydimethylsiloxane(PDMS)composite film-based clip-like hybrid nanogenerator(HNG)device,producing an enhanced electrical output from the applied mechanical movements.The ANb MPs with a high dielectric constant were initially synthesized and embedded inside the PDMS polymer matrix.Various HNGs were fabricated utilizing ANb MPs/PDMS composite films/aluminum tape as negative/positive triboelectric films,respectively and operated in contact-separation mode.The electrical output from them was comparatively analyzed to investigate an optimum concentration of the ANb MPs inside the PDMS film.The robust HNG with 5 wt%ANb MPs/PDMS composite film produced the highest electrical output with promising stability.Thereafter,three similar optimized HNGs were fabricated and integrated within a 3D-printed clip-like structure and the electrical output was thoroughly evaluated while combining multiple HNGs as well as from each independent HNG.The clip-like HNG device exhibited an electrical output of 340 V and 20μA that can be further utilized to charge various capacitors and power portable electronics.Owing to the high resilience structure of the clip-like HNG device,it was also demonstrated to harvest biomechanical energy produced by human movements into electricity.The mechanical energy harvesting when the clip-like HNG device was attached to the accelerator pedal of the car and the pedal of a musical piano was successfully demonstrated.
基金support from the National Natural Science Foundation of China (Grant Nos.51772175,52072218,and 52002192)Natural Science Foundation of Shandong Province (Grant Nos.ZR2020QE042,ZR2022ZD39,and ZR2022ME031)+6 种基金the Science,Education and Industry Integration Pilot Projects of Qilu University of Technology (Shandong Academy of Sciences) (Grant Nos.2022GH018 and 2022PY055)support from the Jinan City Science and Technology Bureau (Grant No.2021GXRC055)the Education Department of Hunan Province/Xiangtan University (Grant No.KZ0807969)funding for top talents at Qilu University of Technology (Shandong Academy of Sciences)support from the Jiangsu Province NSFC (Grant No.BK20180764)support from the National Key R&D Program of China (Grant No.2021YFB3601504)Natural Science Foundation of Shandong Province (Grant No.ZR2020KE019).
文摘Due to its lead-free composition and a unique double polarization hysteresis loop with a large maximum polarization(Pmax)and a small remnant polarization(Pr),AgNbO_(3)-based antiferroelectrics(AFEs)have attracted extensive research interest for electric energy storage applications.However,a low dielectric breakdown field(Eb)limits an energy density and its further development.In this work,a highly efficient method was proposed to fabricate high-energy-density Ag(Nb,Ta)O_(3) capacitor films on Si substrates,using a two-step process combining radio frequency(RF)-magnetron sputtering at 450℃and post-deposition rapid thermal annealing(RTA).The RTA process at 700℃led to sufficient crystallization of nanograins in the film,hindering their lateral growth by employing short annealing time of 5 min.The obtained Ag(Nb,Ta)O_(3) films showed an average grain size(D)of~14 nm(obtained by Debye-Scherrer formula)and a slender room temperature(RT)polarization-electric field(P-E)loop(Pr≈3.8 mC·cm^(−2) and P_(max)≈38 mC·cm^(−2) under an electric field of~3.3 MV·cm^(−1)),the P-E loop corresponding to a high recoverable energy density(W_(rec))of~46.4 J·cm^(−3) and an energy efficiency(η)of~80.3%.Additionally,by analyzing temperature-dependent dielectric property of the film,a significant downshift of the diffused phase transition temperature(T_(M2-M3))was revealed,which indicated the existence of a stable relaxor-like AFE phase near the RT.The downshift of the T_(M2-M3) could be attributed to a nanograin size and residual tensile strain of the film,and it led to excellent temperature stability(20-240℃)of the energy storage performance of the film.Our results indicate that the Ag(Nb,Ta)O_(3) film is a promising candidate for electrical energy storage applications.
基金supported by the Natural Science Foundation of Hebei Province,China(E2021201044)the National Natural Science Foundation of China(51802068 and 52073144).
文摘Antiferroelectric(AFE)materials are promising for the applications in advanced high-power electric and electronic devices.Among them,AgNbO_(3)(AN)-based ceramics have gained considerable attention due to their excellent energy storage performance.Herein,multiscale synergistic modulation is proposed to improve the energy storage performance of AN-based materials,whereby the multilayer structure is employed to improve the breakdown strength(Eb),and Sm/Ta doping is utilized to enhance the AFE stability.As a result,ultrahigh recoverable energy storage density(Wrec)up to 15.0 J·cm^(-3) and energy efficiency of 82.8%are obtained at 1500 kV·cm^(-3) in Sm/Ta co-doped AN multilayer ceramic capacitor(MLCC),which are superior to those of the state-of-the-art AN-based ceramic capacitor.Moreover,the discharge energy density(Wa)in direct-current charge-discharge performance reaches 9.1 J·cm^(-3),which is superior to that of the reported lead-free energy storage systems.The synergistic design of composition and multilayer structure provides an applicable method to optimize the energy storage performance in all dielectric energy storage systems.
基金financially supported by the National Natural Science Foundation of China(Nos.52073144,51802068)the Natural Science Foundation of Hebei Province,China(No.E2021201044)+2 种基金the Natural Science Foundation of Jiangsu Province,China(No.BK20201301)Qing Lan Project,the State Key Laboratory of New Ceramic and Fine Processing Tsinghua University(Nos.KF202005,KF202114)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Antiferroelectric materials are promising candidates for energy-storage applications due to their double hysteresis loops,which can deliver high power density.Among the antiferroelectric materials,AgNbO_(3)is proved attractive due to its environmental-friendliness and high potential for achieving excellent energy storage performance.However,the recoverable energy storage density of AgNbO_(3)ceramics is limited by their relatively low breakdown strength.Herein,the breakdown strength of the pure AgNbO_(3)ceramics prepared using the tape casting method is enhanced to 307 kV·cm^(-1),which is,to the best of our knowledge,among the highest values reported for pure AgNbO-3bulk ceramics.The high breakdown strength may be due to its dense microstructure and good crystallinity obtained by the tape casting method and the optimized sintering temperature.Owing to its enhanced breakdown strength,AgNbO_(3)ceramics show high recoverable energy storage density of 2.8 J·cm^(-3).These results have led to the development of lead-free antiferroelectric materials and devices with high energy storage density.
基金This work was supported by the National Natural Science Foundation of China(No.51802068 and No.52073144)the Natural Science Foundation of Hebei Province,China(No.E2021201044)+1 种基金the Natural Science Foundation of Jiangsu Province,China(No.BK20201301)the State Key Laboratory of New Ceramic and Fine Processing Tsinghua University(No.KF202114).
文摘Lead-free antiferroelectric ceramics with high energy storage performance show great potential in pulsed power capacitors.However,poor breakdown strength and antiferroelectric stability are the two main drawbacks that limit the energy storage performance of antiferroelectric ceramics.Herein,highquality(Ag_(1-x)Na_(x))(Nb_(1-x)Ta_(x))O_(3)ceramics were prepared by the tape casting process.The breakdown strength was greatly improved as a result of the high density and fine grains,while the antiferroelectric stability was enhanced owning to the M2 phase.Benefiting from the synergistic improvement in breakdown strength and antiferroelectric stability,(Ag_(0.80)Na_(0.20))(Nb_(0.80)Ta_(0.20))O_(3)ceramic reveals a benign energy storage performance of W_(rec)=5.8 J/cm^(3)and h=61.7%with good temperature stability,frequency stability and cycling reliability.It is also found that the high applied electric field can promote the M2-M3 phase transition,which may provide ideas to improve the thermal stability of the energy storage performance in AgNbO_(3)-based ceramics.
基金supported by the Royal Society Research Grant(RGSR1221252).
文摘It is crucial to discover lead-free materials with ultrahigh recoverable energy density(Wrec)that can be employed in future pulse power capacitors.In this work,a high Wrec of 4.51 J/cm^(3) was successfully obtained in lead-free Nd-doped AgNb_(0.8)Ta_(0.2)O_(3) antiferroelectric ceramics at an applied electric field of 290 kV/cm.It is discovered that Nd doping paired with Nb-site vacancies could stabilize the antiferroelectric phase by lowering the temperatures of the M1-M2 and M2-M3 phase transitions,which leads to higher energy storage efficiency.Furthermore,Nd and Ta co-doping will contribute to the electrical homogeneity and low electrical conductivity,resulting in large breakdown strengths.Aliovalent doping in Ag-site with Nb-site vacancies serves as a novel strategy for the construction of AgNbO_(3)-based ceramics with excellent energy storage performance.
基金supported by the National Key R&D Program of China(Grant No.2019YFB1503500)the National Natural Science Foundation of China(Grant Nos.51872079,52172113)+1 种基金the Natural Science Foundation of Hubei Province(Grant Nos.2019CFA006,2019CFA055)the Program for Science and Technology Innovation Team in Colleges of Hubei Province(T201901).
文摘AgNbO_(3)based antiferroelectric(AFE)ceramics have large maximum polarization and low remanent polarization,and thus are important candidates for fabricating dielectric capacitors.However,their energy storage performances have been still large difference with those of lead-based AFEs because of their room-temperature ferrielectric(FIE)behavior.In this study,novel La^(3+)and Ta^(5+)co-substituted AgNbO_(3)ceramics are designed and developed.The introduction of La^(3+)and Ta^(5+)decreases the tolerance factor,reduces the polarizability of B-site cations and increases local structure heterogeneity of AgNbO_(3),which enhance AFE phase stability and refine polarization-electric field(PeE)loops.Besides,adding La^(3+)and Ta^(5+)into AgNbO_(3)ceramics causes the decrease of the grain sizes and the increase of the band gap,which contribute to increased Eb.As a consequence,a high recoverable energy density of 6.79 J/cm3 and large efficiency of 82.1%,which exceed those of many recently reported AgNbO_(3)based ceramics in terms of overall energy storage properties,are obtained in(Ag0.88La0.04)(Nb0.96Ta0.04)O_(3)ceramics.Furthermore,the discharge properties of the ceramic with discharge time of 16 ns and power density of 145.03 MW/cm3 outperform those of many lead-free dielectric ceramics.
基金supported by the National Natural Science Foundation of China(No.51802068 and No.52073144)Advanced Talents Incubation Program of the Hebei University,China(No.801260201180)+2 种基金the Natural Science Foundation of Jiangsu Province,China(No.BK20201301)the State Key Laboratory of New Ceramic and Fine Processing Tsinghua University(No.KF202005)the Basic Scientific Research Program of National Institute of Metrology(No.AKY1949).
文摘Antiferroelectric materials with double hysteresis loops are attractive for energy storage applications,which are becoming increasingly important for power electronics nowadays.Among them,AgNbO_(3) based lead-free ceramics have attracted intensive interest as one of promising environmental-friendly candidates.However,most of the AgNbO_(3) based ceramics suffers from low dielectric breakdown strength(Eb).The limitation of low Eb is broken to some extent in this work.Here,AgNbO_(3) epitaxial films were fabricated by pulsed laser deposition,which possess high Eb of 624 kV/cm.The(001)AgNbO_(3) epitaxial film reveals typical antiferroelectric hysteresis loops when the applied electric fields are over 300 kV/cm.A recoverable energy density of 5.8 J/cm^(3) and an energy efficiency of 55.8%are obtained at 600 kV/cm,which demonstrates the great promise of the AgNbO_(3) film for energy storage applications.
基金Supported by Science and Technology Department of Jilin Province(20200101018JC,20190303086SF and 20200201011JC)。
文摘The solid-phase photocataKtic degradation of polyvinyl chloride(PVC)plastic with AgNbO_(3)/Fe_(2)O_(3) is studied under visible-light irradiation.The PVC-(AgNbO_(3)/Fe_(2)O_(3))samples are characterized by X-ray photoelectron spectroscope(XPS),scanning electron microscope(SEM),gas chromatography(GC),and UV-vis diffusion reflectance spectra(UV-vis DRS).The photocatalytic properties of PVC-(AgNbO_(3)/Fe_(2)O_(3))samples are systematically investigated.More amounts of generated CO2,greater texture change and higher weight loss rate were exhibited in the system of PVC-(AgNbO_(3)/Fe_(2)O_(3))than pure PVC film.The weight loss rate is ten times higher than that of pure PVC film,which reaches to 46.53%with optimum amount of O.5wt% Fe_(2)O_(3).Active radicals generate primarily on the surface of Fe_(2)O_(3) particles,which cause composite plastic decomposition on the PVC-(AgNbO_(3)/Fe_(2)O_(3))interface and extend into polymer interor.The study provides a new promising way to degrade the plastic waste under visible-light.
