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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 561-569页

作者：孙家乐 XIONG Peifeng 郝华 liu hanxing State Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Material Science and EngineeringInternational School of Material Science and EngineeringWuhan University of TechnologyWuhan 430070China Sanya Science and Education Innovation Park Wuhan University of TechnologySanya 572000China Foshan Xianhu Laboratory of the Advanced Energy Science and Technology Guangdong Laboratory Xianhu Hydrogen ValleyFoshan 528200China

A machine learning(ML)-based random forest(RF)classification model algorithm was employed to investigate the main factors affecting the formation of the core-shell structure of BaTiO_(3)-based ceramics and their interpretability was analyzed by using Shapley additive explanations(SHAP).An F1-score changed from 0.8795 to 0.9310,accuracy from 0.8450 to 0.9070,precision from 0.8714 to 0.9000,recall from 0.8929 to 0.9643,and ROC/AUC value of 0.97±0.03 was achieved by the RF classification with the optimal set of features containing only 5 features,demonstrating the high accuracy of our model and its high *** the interpretability analysis of the model,it was found that the electronegativity,melting point,and sintering temperature of the dopant contribute highly to the formation of the core-shell structure,and based on these characteristics,specific ranges were delineated and twelve elements were finally obtained that met all the requirements,namely Si,Sc,Mn,Fe,Co,Ni,Pd,Er,Tm,Lu,Pa,and *** the process of exploring the structure of the core-shell,the doping elements can be effectively localized to be selected by choosing the range of features.

关键词： machine learning BaTiO_(3) core-shell structure random forest classifier

Deep-learning enabled atomic insights into the phase transitions and nanodomain topology of lead-free(K,Na)NbO_(3) ferroelectrics

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Science China Materials 2024年第9期67卷 3029-3038页

作者： Xu Zhang Bei Li Ji Zou hanxing liu Ben Xu Kai liu School of Materials Science and Engineering Research Center for Materials Genome EngineeringWuhan University of TechnologyWuhan430070China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan430070China International School of Materials Science and Engineering Wuhan University of TechnologyWuhan430070China Graduate School China Academy of Engineering PhysicsBeijing100193China

Lead-free K_(x)Na_(1-x)NbO_(3)(KNN)perovskites have garnered increasing attention due to their exceptional ferropiezoelectric properties,which are effectively tuned via polymorphic structures and domain ***,atomic insights into the underlying nanomechanisms governing the ferroelectricity of KNNs amidst varying factors such as composition,phase,and domain are still ***,we perform molecular dynamics simulations of phase transitions and domain dynamics for KNNs with various K/Na ratios(x=0.25∼1.0)by using ab-initio accuracy deep learning potential(DP).As a demonstration of its transferability,the newly developed DP model shows quantum accuracy in terms of the equation of states,elastic constants,and phonon dispersion relations for various KNbO_(3)and K_(0.5)Na_(0.5)NbO_(3).Furthermore,intricate temperature-dependent phase transitions and domain formation of KNNs are extensively and quantitatively *** indicate that for KNNs with compositions x ranging from 0.25 to 1.0,the paraelectric-to-ferroelectric phase transition of KNNs is driven primarily by the order-disorder effect,while the displacive effect is dominant in the subsequent ferroelectric phase ***,flux-closure or herringbone-like nanodomain patterns arranged with 90°domain walls formed close to the experimental *** analyses reveal that favorable 90°domain wall formation becomes more challenging with increasing Na content due to distinct oxygen octahedron distortion arising from the different ionic radii of K/Na *** is envisioned that the combination of unified DP and atomistic simulations will help offer a robust solution for more accurate and efficient in silico explorations of complex structural,thermodynamic,and ferroelectric properties for relevant energy storage and conversion materials.

关键词： KNN molecular dynamics deep potential phase transitions domain dynamics

Preparation and Photostriction Properties of BiFeO_(3)-BaTiO_(3)Ceramics

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Journal of Wuhan University of Technology(Materials Science) 2024年第5期39卷 1079-1086页

作者： ZHENG Zewei ZHANG Liqiang CHEN Chen CAO Minghe YI Zhiguo liu hanxing School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China School of Microelectronics Shanghai UniversityShanghai 200444China International School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

Under illumination by 405,520 and 655 nm monochromatic visible light(light intensity of 30 kW/m^(2)),large photostriction(ΔL/L)of 0.19%,0.13%and 0.26%for 67BiFeO_(3)-33BaTiO_(3)(67BF-33BT)lead-free ferroelectric ceramics are obtained,*** studying the ferroelectric and photoelectric properties in conjunction with in situ Raman spectroscopy,it is found that the photostrictive effect of 67BF-33BT is not caused by the electrical strain induced by abnormal photovoltaic voltage,but related to the optical induced oxygen octahedral *** 67BF-33BT lead-free ferroelectric material with excellent photostrictive response in the visible light region is expected to play an important role in the field of optical drive electromechanical devices.

关键词： ferroelectric ceramics photostrictive effect visible light response

Sr_(0.7)Bi_(0.2)TiO_(3)改性Bi_(0.5)Na_(0.5)TiO_(3)基薄膜电储能特性的优化

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硅酸盐学报 2024年第4期52卷 1374-1383页

作者：王鑫郝华李东旭曹明贺尧中华甘小燕刘韩星武汉理工大学三亚科教创新园海南三亚572000 武汉理工大学材料科学与工程学院材料科学与工程国际化示范学院(材料与微电子学院)材料复合新技术国家重点实验室武汉430070

无铅(Bi_(0.5)Na_(0.5))TiO_(3)(BNT)基弛豫铁电薄膜以其高Curie温度和大极化在介质储能中受到广泛关注,然而较低的击穿电场限制了它们的应用。选择Sr_(0.7)Bi_(0.2)TiO_(3)(SBT)作为固溶组元,通过组分调控提高薄膜击穿强度,优化储能性... 详细信息

无铅(Bi_(0.5)Na_(0.5))TiO_(3)(BNT)基弛豫铁电薄膜以其高Curie温度和大极化在介质储能中受到广泛关注,然而较低的击穿电场限制了它们的应用。选择Sr_(0.7)Bi_(0.2)TiO_(3)(SBT)作为固溶组元,通过组分调控提高薄膜击穿强度,优化储能性能。结果表明:BNT–xSBT薄膜均为单一钙钛矿结构,没有明显的第二相。随SBT含量增加,晶胞参数先增大后降低,介电常数略微下降,介电损耗保持稳定,击穿强度先上升后降低。最终,在最优组分样品BNT–0.40SBT中获得了3622.25 kV/cm的高击穿强度和85.99 J/cm^(3)的高储能密度。这种优异的能量存储密度和出色的稳定性,表明样品BNT–0.40SBT是脉冲功率和电力电子应用电容器的有前途的候选者。

关键词：电介质电容器薄膜击穿强度储能性能

Synthesis and characterization of LiNi_(0.95-x)Co_xAl_(0.05)O_2 for lithium-ion batteries

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Rare Metals 2006年第4期25卷 303-308页

作者： ZHU Xianjun ZHAN Hui liu hanxing ZHOU Yunhong State Key Laboratory of Advanced Technology and Processing for Materials Synthesis and Processing Wuhan University of Technology Wuhan430070 China College of Chemical and Molecular Science Wuhan University Wuhan 430072 China

Samples of LiNi0.95-xCoxAl0.05O2 （x = 0.10 and 0.15） and LiNiO2, synthesized by the solid-state reaction at 725℃ for 24 h from LiOH-H2O, Ni2O3, Co2O3, and AI（OH）3 under an oxygen stream, were characterized by TG-DTA, XRD, SEM, and electrochemical tests. Simultaneous doping of cobalt and aluminum at the Ni-site in LiNiO2 was tried to improve the cathode performance for lithium-ion batteries. The results showed that co-doping （especially, 5 at.% A1 and 10 at.% Co） definitely had a large beneficial effect in increasing the capacity （186.2 mA.h/g of the first discharge capacity for LiNio.s.42OoaoAlo.0502） and cycling behavior （180.1 mA-h/g after 10 cycles for ***2） compared with 180.7 mA.h/g of the first discharge capacity and 157.7 mA.h/g of the tenth discharge capacity for LiNiO2, respectively. Differen- tial capacity versus voltage curves showed that the co-doped LiNio.95_***2 had less intensity of the phase transitions than the pristine LiNiO2.

关键词： electrochemistry LiNi0.95-xCoxAl0.05O2 lithium-ion batteries co-doping cathode materials LiNiO2

Ab Initio Study of Doping Mechanisms in BaTiO3-BiYO3

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Journal of Wuhan University of Technology(Materials Science) 2016年第3期31卷 543-547页

作者：张文芹 huang xuechen liu hanxing State Key Laboratory of Advanced Technology for Composite Materials Wuhan University of TechnologyWuhan 430070China

A density functional plane-wave pseudopotential method is used to study the doping mechanisms of impurity defects（BiBa, YTi） in BaTiO3- BiYO3. Single BiBa and YTi impurities have little structure distortion. Bi forms ionic bond with nearby O atom in single Bi impurity, Y formed [YO6] octahedral in single Y impurity. However, in the co-doped BiB~ and Yr~ structure, Bi formed three valence bonds with nearby O atom, which causes the large structure distortion. The doped ion makes the mobile of Ti4~ difficult and loss local ferroelectricity, which will broaden the dielectric constant temperature curve and increase the temperature stability of BaTiO3 ceramic matrix.

关键词： BaTiO3-BiYO3 temperature stability doping mechanism DFT

Enhanced Electrochemical Performances of Ni Doped Cr_(8)O_(21)Cathode Materials for Lithium-ion Batteries

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Journal of Wuhan University of Technology(Materials Science) 2023年第6期38卷 1242-1247页

作者： TANG Guoli liu hanxing YU Zhiyong YANG Bo KONG Linghua School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China International School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan 430070China

Cathode materials,nickel doped Cr_(8)O_(21),were synthesized by a solid-state *** effects of Ni doping on the electrochemical performances of Cr_(8)O_(21) were *** experimental results show that the discharge capacities of the samples depend on the nickel contents,which increases firstly and then decreases with increasing Ni *** Ni_(0.5)Cr_(7.5)O_(21)delivers a first capacity up to 392.6 m Ah·g^(-1)at *** addition,Ni doped sample also demonstrates enhanced cycling stability and rate capability compared with that of the bare Cr_(8)O_(21).At 1 C,an initial discharge capacity of 348.7 m Ah·g^(-1)was achieved for Ni_(0.5)Cr_(7.5)O_(21),much higher than 271.4 m Ah·g^(-1)of the un-doped sample,with an increase of more than 28%.Electrochemical impedance spectroscopy results confirm that Ni doping reduces the growth of interface resistance and charge transfer resistance,which is conducive to the electrochemical kinetic behaviors during charge-discharge.

关键词： Cr_(8)O_(21) cathode material doping electrochemical performances lithium-ion batteries

Preparation of layered oxide Li(Co_(1/3)Ni_(1/3)Mn_(1/3))O_2 via the sol-gel process

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Rare Metals 2008年第2期27卷 158-164页

作者： ZHANG Wen liu hanxing HU Chen ZHU Xianjun LI Yanxi State Key Laboratory of Advanced Technology for Material Synthesis and Processing Wuhan University of Technology Wuhan 430070 China

To obtain homogenous layered oxide Li（Co1/3Ni1/3Mn1/3）O2 as a lithium insertion positive electrode material, the sol-gel process using citric acid as a chelating agent was applied. The material Li（Co1/3Ni1/3Mn1/3）O2 was synthesized at different calcination temperatures. XRD experiment indicated that the layered Li（Co1/3Ni1/3Mn1/3）O2 material could be synthesized at a lower temperature of 800℃, and the oxidation state of Co, Ni, and Mn in the cathode confirmed by XPS were ＋3, ＋2, and ＋4, respectively. SEM observations showed that the synthesized material could form homogenous particle morphology with the particle size of about 200 nm. In spite of different calcination temperatures, the charge-discharge curves of all the samples for the initial cycle were similar, and the cathode synthesized at 900℃ showed a small irreversible capacity loss of 11.24% and a high discharge capacity of 212.2 mAh·g^-1 in the voltage range of 2.9-4.6 V.

关键词： lithium-ion battery layered transition metal oxide sol-gel process high capacity

Influence of Organic Cations on the Crystal and Electronic Structures of Two-dimensional Lead Iodide Perovskites

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Journal of Wuhan University of Technology(Materials Science) 2023年第3期38卷 496-504页

作者：杜定谨甘小燕 LU Shun ZHENG Wei GUO Liling liu hanxing School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China International School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

The crystal structures and electronic structures(including band gap,project density of states,partial charge density,effective mass and electron localization function)of the 2D lead iodide perovskites hybrids with different organic spacer cations of 4-fluorophenylethanaminium(4F-PEA^(+)),ethanolamine(EA^(+)),thienylethylamine(TEA^(+))were investigated using first-principles *** was found the higher dipole moment,the stronger the hydrogen bonding between the organic amino and iodide in the inorganic layer,and the larger the[PbI_(6)]^(4-)octahedral distortions in these crystal *** quantifying the degree of the distortions using OctaDist software showed that the distortion of adjacent[PbI_(6)]^(4-)octahedra had a decisive effect on the band ***,the greater deviation of Pb-I-Pb bond angles from 180°,together with the larger distortion of multiple[PbI_(6)]^(4-)octahedron resulted in a wider band gap,which was verified by calculated band gap using different DFT *** results outlined the relationships of hydrogen bonding,ocathedra distortion and band structure in 2D perovskites,highlighting the importance of the cations on the structural tuning and optoelectronic properties.

关键词： 2D perovskites density functional theory(DFT) octahedral distortion 4F-PEA EA TEA

First Principle Study of Cesium-based Lead-free Halide Double Perovskites

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Journal of Wuhan University of Technology(Materials Science) 2023年第3期38卷 520-529页

作者：郑伟甘小燕 DU Dingjin WANG Yajie DAI Siqi GUO Liling liu hanxing School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China International School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China

Inorganic halide double perovskites A_(2)B'B"X_(6) have gained significant interests for their diverse composition,stable physicochemical properties,and potential for photoelectric *** influences of trivalent and monovalent cations on the formation energy,decomposition energy,electronic structure and optical properties of cesium-based lead-free Cs^(+)_(2)B'B"Br_(6) (B'=Na^(+),In^(+)Cu^(+),or Ag^(+);B"=Bi^(3),Sb^(3+),In^(3+)) are systematically *** view of the analysis and results of the selected double perovskites,for the double perovskites with different B-site trivalent cation,the band gap increases in the order of Cs_(2)AgInBr_(6),Cs_(2)AgSbBr_(6) and Cs_(2)AgBiBr_(6),with Cs_(2)AgBiBr_(6) possessing the highest thermodynamic ***,the Bi-based perovskites are further studied to elucidate the effect of monovalent cation on their stability and *** show that the thermodynamic stability rises in the sequence of Cs_(2)NaBiBr_(6),Cs_(2)InBiBr_(6),Cs_(2)AgBiBr_(6) and Cs_(2)CuBiBr_(6).Notably,Cs_(2)CuBiBr_(6) exhibits a relatively narrow and appropriate band gap of 1.4634 eV,together with the highest absorption coefficient than other compounds,suggesting that Cs_(2)CuBiBr_(6) is a promising light absorbing material that can be further explored experimentally and be applied to optoelectronic *** research offers theoretical backing for the potential optoelectronic application of cesium-based lead-free halide double perovskites in solar energy conversion.

关键词： lead-free double perovskites density functional theory Cs_(2)B'B"Br_(6) stability electronic properties optical property stability