Small-sized Cd_(x) Zn_(1-x) S solid solution nanomaterial is an important candidate for efficient photocatalytic hydrogen evolution(PHE),but it still suffers from easy agglomeration,severe photo corrosion,and fast pho...Small-sized Cd_(x) Zn_(1-x) S solid solution nanomaterial is an important candidate for efficient photocatalytic hydrogen evolution(PHE),but it still suffers from easy agglomeration,severe photo corrosion,and fast photogenerated electron-hole recombination.To tackle these issues,herein,we propose a new strategy to modify Cd_(x) Zn_(1-x) S nanoreactors by the simultaneous utilization of ionic-liquid-assisted morphology engineering and MXene-incorporating method.That is,we designed and synthesized a novel hierarchi-cal Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) Schottky junction composite through the in-situ deposition of ultrathin Cd_(0.8) Zn_(0.2) S nanosheets on unique IL-modified Ti_(3) C_(2) MXenes by a one-pot solvothermal method for efficiently PHE.The unique construction strategy tailors the thickness of ultrathin Cd_(0.8) Zn_(0.2) S nanosheets and prevents them from stacking and agglomeration,and especially,optimizes their charge transfer pathways during the photocatalytic process.Compared with pristine Cd_(0.8) Zn_(0.2) S nanosheets,Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) has abun-dant photogenerated electrons available on the Ti_(3) C_(2) surface for proton reduction reaction,owing to the absence of deep-trapped electrons,suppression of electron-hole recombination in Cd_(0.8) Zn_(0.2) S and high-efficiency charge separation at the Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) Schottky junction interface.Moreover,the hy-drophilicity,electrical conductivity,visible-light absorption capacity,and surficial hydrogen desorption of Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) heterostructure are significantly improved.As a result,the heterostructure exhibits out-standing photocatalytic stability and super high apparent quantum efficiency,being rendered as one of the best noble-metal-free Cd-Zn-S-based photocatalysts.This work illustrates the mechanisms of mor-phology control and heterojunction construction in controlling the catalytic behavior of photocatalysts and highlights the great potential of the IL-assisted route in the synthesis of high-performance MXene-based heterostructures for photocatalytic hydrogen evolution.展开更多
Pb(Zr,Ti)O_(3)-Pb(Zn_(1/3)Nb_(2/3))O_(3) (PZT-PZN) based ceramics, as important piezoelectric materials, have a wide range of applications in fields such as sensors and actuators, thus the optimization of their piezoe...Pb(Zr,Ti)O_(3)-Pb(Zn_(1/3)Nb_(2/3))O_(3) (PZT-PZN) based ceramics, as important piezoelectric materials, have a wide range of applications in fields such as sensors and actuators, thus the optimization of their piezoelectric properties has been a hot research topic. This study investigated the effects of phase boundary engineering and domain engineering on (1-x)[0.8Pb(Zr_(0.5)Ti_(0.5))O_(3)-0.2Pb(Zn_(1/3)Nb_(2/3))O_(3)]-xBi(Zn_(0.5)Ti_(0.5))O_(3) ((1-x)(0.8PZT-0.2PZN)- xBZT) ceramic to obtain excellent piezoelectric properties. The crystal phase structure and microstructure of ceramic samples were characterized. The results showed that all samples had a pure perovskite structure, and the addition of BZT gradually increased the grain size. The addition of BZT caused a phase transition in ceramic samples from the morphotropic phase boundary (MPB) towards the tetragonal phase region, which is crucial for optimizing piezoelectric properties. By adjusting content of BZT and precisely controlling position of the phase boundary, the piezoelectric performance can be optimized. Domain structure is one of the key factors affecting piezoelectric performance. By using domain engineering techniques to optimize grain size and domain size, piezoelectric properties of ceramic samples have been significantly improved. Specifically, excellent piezoelectric properties (piezoelectric constant d_(33)=320 pC/N, electromechanical coupling factor kp=0.44) were obtained simultaneously for x=0.08. Based on experimental results and theoretical analysis, influence mechanisms of phase boundary engineering and domain engineering on piezoelectric properties were explored. The study shows that addition of BZT not only promotes grain growth, but also optimizes the domain structure, enabling the polarization reversal process easier, thereby improving piezoelectric properties. These research results not only provide new ideas for the design of high-performance piezoelectric ceramics, but also lay a theoretical foundation for development of related electronic devices.展开更多
Constructing S-scheme heterojunctions preserves the intrinsic redox capabilities of both semiconductors while promoting the separation of photogenerated electrons and holes,making it a promising approach for enhancing...Constructing S-scheme heterojunctions preserves the intrinsic redox capabilities of both semiconductors while promoting the separation of photogenerated electrons and holes,making it a promising approach for enhancing the properties of semiconductors.In this study,an S-scheme Cd_(0.8)Zn_(0.2)S-CeO_(2)(CZS-CeO_(2))heterojunction was successfully fabricated via the in-situ growth of CZS nanowires on CeO_(2)nanocubes.The S-scheme charge-transfer mechanism of the CZS-CeO_(2)composites during photocatalytic reactions was confirmed through in-situ X-ray photoelectron spectroscopy and density functional theory calculations.These results demonstrate that the interfacial electric field(IEF)significantly facilitates charge separation and transport within the heterojunction.Consequently,the CZS-CeO_(2)composites exhibited excellent photocatalytic hydrogen production performance under simulated sunlight irradiation,surpassing that of blank CZS.Particularly,the optimal photocatalytic hydrogen generation rate for CZS-15%CeO_(2)reached 58 mmol·g^(-1)·h^(-1),approximately 8.8 times higher than that of blank CZS.After five consecutive cycles of testing,CZS-15%CeO_(2)retained a relatively high level of activity.This enhanced stability can be attributed to the fabrication of S-scheme heterojunctions,which effectively suppressed hole-induced photocorrosion of CZS.This investigation provides a beneficial reference for the rational design of S-scheme heterojunction photocatalysts for efficient and stable photocatalytic hydrogen production.展开更多
BaCe_(0.8)Y_(0.2)O_(3)-αceramics exhibit superior conductivity among related materials.However,the hightemperature sintering makes it difficult to prepare electrochemical devices with a BaCe_(0.8)Y_(0.2)O_(3)-αmulti...BaCe_(0.8)Y_(0.2)O_(3)-αceramics exhibit superior conductivity among related materials.However,the hightemperature sintering makes it difficult to prepare electrochemical devices with a BaCe_(0.8)Y_(0.2)O_(3)-αmultilayer film,and very few studies have examined the conductivity and transport properties of unsintered BaCe_(0.8)Y_(0.2)O_(3)-α.In nominally dry conditions,the instability of this material in a watercontaining atmosphere can be minimized,allowing the unsintered BaCe_(0.8)Y_(0.2)O_(3)-αto be applied in some particular test environment as a component of electrochemical devices.Hence,the conductivity of unsintered BaCe_(0.8)Y_(0.2)O_(3)-αin dry conditions was measured via AC impedance spectroscopy in the temperature range of 500-800℃.The unsintered BaCe_(0.8)Y_(0.2)O_(3)-αexhibits high conductivity and hydration ability,as well as low proton activation energy.In addition,it shows high oxygen vacancy and low proton transport numbers at high temperature,limited by its grain boundaries.This work provides insights into the conductivity and proton transport of unsintered BaCe_(0.8)Y_(0.2)O_(3)-αand demonstrates its potential as a proton-conducting electrolyte.展开更多
Three sets of MXene(Ti_(3)C_(2)T_(x))@nano-Fe_(1)Co_(0.8)Ni_(1)composites with 15,45,and 90 mg MXene were prepared by in-situ liquid-phase deposition to effectively investigate the impact of the relationship between M...Three sets of MXene(Ti_(3)C_(2)T_(x))@nano-Fe_(1)Co_(0.8)Ni_(1)composites with 15,45,and 90 mg MXene were prepared by in-situ liquid-phase deposition to effectively investigate the impact of the relationship between MXene(Ti_(3)C_(2)T_(x))and nano-Fe_(1)Co_(0.8)Ni_(1)magnetic particles on the electromagnetic absorption properties of the composites.The microstructure,static magnetic properties,and electromag-netic absorption performance of these composites were studied.Results indicate that the MXene@nano-Fe_(1)Co_(0.8)Ni_(1)composites were primarily composed of face-centered cubic crystal structure particles and MXene,with spherical Fe_(1)Co_(0.8)Ni_(1)particles uniformly distrib-uted on the surface of the multilayered MXene.The alloy particles had an average particle size of approximately 100 nm and exhibited good dispersion without noticeable particle aggregation.With the increase in MXene content,the specific saturation magnetic and coer-civity of the composite initially decreased and then increased,displaying typical soft magnetic properties.Compared with those of the Fe_(1)Co_(0.8)Ni_(1)magnetic alloy particles alone,MXene addition caused an increasing trend in the real and imaginary parts of the dielectric constant of the composite.Meanwhile,the real and imaginary parts of the magnetic permeability exhibit decreasing trend.With the in-crease in MXene addition,the material attenuation constant increased and the impedance matching decreased.The minimum reflection loss increased,and the maximum effective absorption bandwidth decreased.When the MXene addition was 90 mg,the composite exhib-ited a minimum reflection loss of-46.9 dB with a sample thickness of 1.1 mm and a maximum effective absorption bandwidth of 3.60 GHz with a sample thickness of 1.0 mm.The effective absorption bandwidth of the composites and their corresponding thicknesses showed a decreasing trend with the increase in MXene addition,reducing by 50%from 1.5 mm without MXene addition to 1 mm with 90 mg of MXene addition.展开更多
Dry reforming of methane(DRM)converts CH4 and CO_(2) to syngas.Photothermal DRM,which integrates temperature and light,is a sustainable method for storing solar energy in molecules.However,challenges such as limited l...Dry reforming of methane(DRM)converts CH4 and CO_(2) to syngas.Photothermal DRM,which integrates temperature and light,is a sustainable method for storing solar energy in molecules.However,challenges such as limited light absorption,low photocarrier separation efficiency,Ni sintering,and carbon deposition hinder DRM stability.Herein,we regulated Ni contents in(Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalysts to enhance the optical characteristics while addressing Ni sintering and carbon deposition issues.The(3Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalyst had insufficient Ni content,while the(9Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalyst showed excessive carbon deposition,leading to lower stability compared to the(6Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalyst,which achieved CH4 and CO_(2) rates to 231.0 μmol gcat^(-1)s^(-1) and 294.3 μmol gcat^(-1)s^(-1) ,respectively,at 973 K,with only 0.2 wt.%carbon deposition and no Ni sintering.This work adjusted Ni contents in(Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalysts to enhance DRM performance,which has implications for improving other reactions.展开更多
This study focused on meeting the stringent stability requirements of tubular segmented-in-series solid oxide fuel cells(SOFCs) in reducing and oxidizing atmospheres.To address this challenge,a bi-layer perovskite cer...This study focused on meeting the stringent stability requirements of tubular segmented-in-series solid oxide fuel cells(SOFCs) in reducing and oxidizing atmospheres.To address this challenge,a bi-layer perovskite ceramic interconnect was designed by controlling the oxygen partial pressure,because of the strong correlation between the conductivity of strontium-doped lanthanum titanate(LST) and the oxygen partial pressure.The LST powder was prepared using solid-phase and sol-gel methods,and their influence on particle size and sintering behavior was compared.LST/lanthanum strontium manganite(LSM) bi-layer ceramic interconnects with varying thicknesses were fabricated through screen printing and co-sintering.The results demonstrate favorable interfacial bonding and excellent chemical compatibility between the ceramic layers.The conductivity of the bi-layer interconnect exhibits a temperature-dependent behavior,peaking at 550℃.Simulation calculations and research findings validate that the co nductivity of the bi-layer interconnect is determined by the thickness of the LSM layer and the oxygen partial pressure at the interconnect interface.Optimal conductivity is achieved with a bilayer interconnect consisting of approximately 15 μm of LST and 4 μm of LSM.This can be attributed to the efficient regulation of oxygen partial pressure at the interface,effectively mitigating LSM decomposition caused by low oxygen partial pressure and the subsequent reduction in conductivity.These results provide valuable fundamental data and methodology for the development of high-performance interconnects for tubular segmented-in-series SOFCs.展开更多
As a potential candidate for high-energy lithium-ion batteries (LIBs),nickel-rich cathodes encounter significant challenges due to structural instability arising from interphases.In this work,tris(ethenyl)-tris(etheny...As a potential candidate for high-energy lithium-ion batteries (LIBs),nickel-rich cathodes encounter significant challenges due to structural instability arising from interphases.In this work,tris(ethenyl)-tris(ethenyl)silyloxysilane (HVDS) with Si–O bonds and unsaturated bonds is introduced as additive designing functional electrolyte to enhance the long-cycle stability of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)/graphite LIBs at elevated temperature.The preferential oxidization and component of HVDS facilitate the generation of an extremely robust and ultra-thin cathode electrolyte interphase (CEI) comprising a chemically bonded silane polymer.This interphase effectively suppresses side-reactions of electrolyte,mitigates HF erosion,and reduces irreversible phase transitions.Benefiting from the above merits,the batteries’capacity retention shows a remarkable increase from 20% to 92% after nearly 1550 cycles conducted at room temperature.And under elevated temperature conditions (45℃),the capacity retention remains 80%after 670 cycles,in comparison to a drop to 80%after only 250 cycles with the blank electrolyte.These findings highlight HVDS’s potential to functionalize the electrolyte,marking a breakthrough in improving the longevity and reliability of NCM811/graphite LIBs under challenging conditions.展开更多
基金financial supports pro-vided by the National Natural Science Foundation of China(No.21905279)the Natural Science Foundation of Fujian Province(No.2020J05086).
文摘Small-sized Cd_(x) Zn_(1-x) S solid solution nanomaterial is an important candidate for efficient photocatalytic hydrogen evolution(PHE),but it still suffers from easy agglomeration,severe photo corrosion,and fast photogenerated electron-hole recombination.To tackle these issues,herein,we propose a new strategy to modify Cd_(x) Zn_(1-x) S nanoreactors by the simultaneous utilization of ionic-liquid-assisted morphology engineering and MXene-incorporating method.That is,we designed and synthesized a novel hierarchi-cal Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) Schottky junction composite through the in-situ deposition of ultrathin Cd_(0.8) Zn_(0.2) S nanosheets on unique IL-modified Ti_(3) C_(2) MXenes by a one-pot solvothermal method for efficiently PHE.The unique construction strategy tailors the thickness of ultrathin Cd_(0.8) Zn_(0.2) S nanosheets and prevents them from stacking and agglomeration,and especially,optimizes their charge transfer pathways during the photocatalytic process.Compared with pristine Cd_(0.8) Zn_(0.2) S nanosheets,Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) has abun-dant photogenerated electrons available on the Ti_(3) C_(2) surface for proton reduction reaction,owing to the absence of deep-trapped electrons,suppression of electron-hole recombination in Cd_(0.8) Zn_(0.2) S and high-efficiency charge separation at the Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) Schottky junction interface.Moreover,the hy-drophilicity,electrical conductivity,visible-light absorption capacity,and surficial hydrogen desorption of Cd_(0.8) Zn_(0.2) S/Ti_(3) C_(2) heterostructure are significantly improved.As a result,the heterostructure exhibits out-standing photocatalytic stability and super high apparent quantum efficiency,being rendered as one of the best noble-metal-free Cd-Zn-S-based photocatalysts.This work illustrates the mechanisms of mor-phology control and heterojunction construction in controlling the catalytic behavior of photocatalysts and highlights the great potential of the IL-assisted route in the synthesis of high-performance MXene-based heterostructures for photocatalytic hydrogen evolution.
基金National Natural Science Foundation of China (52202139, 52072178)。
文摘Pb(Zr,Ti)O_(3)-Pb(Zn_(1/3)Nb_(2/3))O_(3) (PZT-PZN) based ceramics, as important piezoelectric materials, have a wide range of applications in fields such as sensors and actuators, thus the optimization of their piezoelectric properties has been a hot research topic. This study investigated the effects of phase boundary engineering and domain engineering on (1-x)[0.8Pb(Zr_(0.5)Ti_(0.5))O_(3)-0.2Pb(Zn_(1/3)Nb_(2/3))O_(3)]-xBi(Zn_(0.5)Ti_(0.5))O_(3) ((1-x)(0.8PZT-0.2PZN)- xBZT) ceramic to obtain excellent piezoelectric properties. The crystal phase structure and microstructure of ceramic samples were characterized. The results showed that all samples had a pure perovskite structure, and the addition of BZT gradually increased the grain size. The addition of BZT caused a phase transition in ceramic samples from the morphotropic phase boundary (MPB) towards the tetragonal phase region, which is crucial for optimizing piezoelectric properties. By adjusting content of BZT and precisely controlling position of the phase boundary, the piezoelectric performance can be optimized. Domain structure is one of the key factors affecting piezoelectric performance. By using domain engineering techniques to optimize grain size and domain size, piezoelectric properties of ceramic samples have been significantly improved. Specifically, excellent piezoelectric properties (piezoelectric constant d_(33)=320 pC/N, electromechanical coupling factor kp=0.44) were obtained simultaneously for x=0.08. Based on experimental results and theoretical analysis, influence mechanisms of phase boundary engineering and domain engineering on piezoelectric properties were explored. The study shows that addition of BZT not only promotes grain growth, but also optimizes the domain structure, enabling the polarization reversal process easier, thereby improving piezoelectric properties. These research results not only provide new ideas for the design of high-performance piezoelectric ceramics, but also lay a theoretical foundation for development of related electronic devices.
文摘Constructing S-scheme heterojunctions preserves the intrinsic redox capabilities of both semiconductors while promoting the separation of photogenerated electrons and holes,making it a promising approach for enhancing the properties of semiconductors.In this study,an S-scheme Cd_(0.8)Zn_(0.2)S-CeO_(2)(CZS-CeO_(2))heterojunction was successfully fabricated via the in-situ growth of CZS nanowires on CeO_(2)nanocubes.The S-scheme charge-transfer mechanism of the CZS-CeO_(2)composites during photocatalytic reactions was confirmed through in-situ X-ray photoelectron spectroscopy and density functional theory calculations.These results demonstrate that the interfacial electric field(IEF)significantly facilitates charge separation and transport within the heterojunction.Consequently,the CZS-CeO_(2)composites exhibited excellent photocatalytic hydrogen production performance under simulated sunlight irradiation,surpassing that of blank CZS.Particularly,the optimal photocatalytic hydrogen generation rate for CZS-15%CeO_(2)reached 58 mmol·g^(-1)·h^(-1),approximately 8.8 times higher than that of blank CZS.After five consecutive cycles of testing,CZS-15%CeO_(2)retained a relatively high level of activity.This enhanced stability can be attributed to the fabrication of S-scheme heterojunctions,which effectively suppressed hole-induced photocorrosion of CZS.This investigation provides a beneficial reference for the rational design of S-scheme heterojunction photocatalysts for efficient and stable photocatalytic hydrogen production.
基金Project supported by the National Natural Science Foundation of China(51834004,51704063,52004057,51774076)the Fundamental Research Funds for the Central Universities(N2225018,N2325006,N2325027)Joint Fund of Henan Province Science and Technology R&D Program(225200810035)。
文摘BaCe_(0.8)Y_(0.2)O_(3)-αceramics exhibit superior conductivity among related materials.However,the hightemperature sintering makes it difficult to prepare electrochemical devices with a BaCe_(0.8)Y_(0.2)O_(3)-αmultilayer film,and very few studies have examined the conductivity and transport properties of unsintered BaCe_(0.8)Y_(0.2)O_(3)-α.In nominally dry conditions,the instability of this material in a watercontaining atmosphere can be minimized,allowing the unsintered BaCe_(0.8)Y_(0.2)O_(3)-αto be applied in some particular test environment as a component of electrochemical devices.Hence,the conductivity of unsintered BaCe_(0.8)Y_(0.2)O_(3)-αin dry conditions was measured via AC impedance spectroscopy in the temperature range of 500-800℃.The unsintered BaCe_(0.8)Y_(0.2)O_(3)-αexhibits high conductivity and hydration ability,as well as low proton activation energy.In addition,it shows high oxygen vacancy and low proton transport numbers at high temperature,limited by its grain boundaries.This work provides insights into the conductivity and proton transport of unsintered BaCe_(0.8)Y_(0.2)O_(3)-αand demonstrates its potential as a proton-conducting electrolyte.
文摘Three sets of MXene(Ti_(3)C_(2)T_(x))@nano-Fe_(1)Co_(0.8)Ni_(1)composites with 15,45,and 90 mg MXene were prepared by in-situ liquid-phase deposition to effectively investigate the impact of the relationship between MXene(Ti_(3)C_(2)T_(x))and nano-Fe_(1)Co_(0.8)Ni_(1)magnetic particles on the electromagnetic absorption properties of the composites.The microstructure,static magnetic properties,and electromag-netic absorption performance of these composites were studied.Results indicate that the MXene@nano-Fe_(1)Co_(0.8)Ni_(1)composites were primarily composed of face-centered cubic crystal structure particles and MXene,with spherical Fe_(1)Co_(0.8)Ni_(1)particles uniformly distrib-uted on the surface of the multilayered MXene.The alloy particles had an average particle size of approximately 100 nm and exhibited good dispersion without noticeable particle aggregation.With the increase in MXene content,the specific saturation magnetic and coer-civity of the composite initially decreased and then increased,displaying typical soft magnetic properties.Compared with those of the Fe_(1)Co_(0.8)Ni_(1)magnetic alloy particles alone,MXene addition caused an increasing trend in the real and imaginary parts of the dielectric constant of the composite.Meanwhile,the real and imaginary parts of the magnetic permeability exhibit decreasing trend.With the in-crease in MXene addition,the material attenuation constant increased and the impedance matching decreased.The minimum reflection loss increased,and the maximum effective absorption bandwidth decreased.When the MXene addition was 90 mg,the composite exhib-ited a minimum reflection loss of-46.9 dB with a sample thickness of 1.1 mm and a maximum effective absorption bandwidth of 3.60 GHz with a sample thickness of 1.0 mm.The effective absorption bandwidth of the composites and their corresponding thicknesses showed a decreasing trend with the increase in MXene addition,reducing by 50%from 1.5 mm without MXene addition to 1 mm with 90 mg of MXene addition.
基金support from the National Natural Science Foundation of China(22078134)State Key Laboratory of Clean and Efficient Coal Utilization of Taiyuan University of Technology(SKL2022006)Natural Science Foundation of Chongqing(CSTB2023NSCQ-MSX0162)are greatly appreciated for the work.
文摘Dry reforming of methane(DRM)converts CH4 and CO_(2) to syngas.Photothermal DRM,which integrates temperature and light,is a sustainable method for storing solar energy in molecules.However,challenges such as limited light absorption,low photocarrier separation efficiency,Ni sintering,and carbon deposition hinder DRM stability.Herein,we regulated Ni contents in(Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalysts to enhance the optical characteristics while addressing Ni sintering and carbon deposition issues.The(3Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalyst had insufficient Ni content,while the(9Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalyst showed excessive carbon deposition,leading to lower stability compared to the(6Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalyst,which achieved CH4 and CO_(2) rates to 231.0 μmol gcat^(-1)s^(-1) and 294.3 μmol gcat^(-1)s^(-1) ,respectively,at 973 K,with only 0.2 wt.%carbon deposition and no Ni sintering.This work adjusted Ni contents in(Ni/Ce_(0.8)Zr_(0.2)O_(2))@SiO_(2) catalysts to enhance DRM performance,which has implications for improving other reactions.
基金Project supported by the National Key Research and Development Program of China (2021YFB4001400)。
文摘This study focused on meeting the stringent stability requirements of tubular segmented-in-series solid oxide fuel cells(SOFCs) in reducing and oxidizing atmospheres.To address this challenge,a bi-layer perovskite ceramic interconnect was designed by controlling the oxygen partial pressure,because of the strong correlation between the conductivity of strontium-doped lanthanum titanate(LST) and the oxygen partial pressure.The LST powder was prepared using solid-phase and sol-gel methods,and their influence on particle size and sintering behavior was compared.LST/lanthanum strontium manganite(LSM) bi-layer ceramic interconnects with varying thicknesses were fabricated through screen printing and co-sintering.The results demonstrate favorable interfacial bonding and excellent chemical compatibility between the ceramic layers.The conductivity of the bi-layer interconnect exhibits a temperature-dependent behavior,peaking at 550℃.Simulation calculations and research findings validate that the co nductivity of the bi-layer interconnect is determined by the thickness of the LSM layer and the oxygen partial pressure at the interconnect interface.Optimal conductivity is achieved with a bilayer interconnect consisting of approximately 15 μm of LST and 4 μm of LSM.This can be attributed to the efficient regulation of oxygen partial pressure at the interface,effectively mitigating LSM decomposition caused by low oxygen partial pressure and the subsequent reduction in conductivity.These results provide valuable fundamental data and methodology for the development of high-performance interconnects for tubular segmented-in-series SOFCs.
基金financially supported by the Scientific Research Innovation Project of Graduate School of South China Normal University (No. 2024KYLX081)。
文摘As a potential candidate for high-energy lithium-ion batteries (LIBs),nickel-rich cathodes encounter significant challenges due to structural instability arising from interphases.In this work,tris(ethenyl)-tris(ethenyl)silyloxysilane (HVDS) with Si–O bonds and unsaturated bonds is introduced as additive designing functional electrolyte to enhance the long-cycle stability of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)/graphite LIBs at elevated temperature.The preferential oxidization and component of HVDS facilitate the generation of an extremely robust and ultra-thin cathode electrolyte interphase (CEI) comprising a chemically bonded silane polymer.This interphase effectively suppresses side-reactions of electrolyte,mitigates HF erosion,and reduces irreversible phase transitions.Benefiting from the above merits,the batteries’capacity retention shows a remarkable increase from 20% to 92% after nearly 1550 cycles conducted at room temperature.And under elevated temperature conditions (45℃),the capacity retention remains 80%after 670 cycles,in comparison to a drop to 80%after only 250 cycles with the blank electrolyte.These findings highlight HVDS’s potential to functionalize the electrolyte,marking a breakthrough in improving the longevity and reliability of NCM811/graphite LIBs under challenging conditions.
