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Progress in Natural Science:Materials International 2024年第3期34卷 591-597页

作者： Dongmei Zhang Yufan Li Yuchao Li Zhonggui Sun Hanxue Zhu Lujia Yang Yanhu Zhan Yankai Li Shi Wang Jun-Wei Zha School of Mathematical Sciences Liaocheng University School of Materials Science and Engineering Liaocheng University State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM) Nanjing University of Posts & Telecommunications School of Chemistry and Biological Engineering University of Science and Technology Beijing

A tri-layered(B-G-B) dielectric films were simply prepared by alternatively spin-coating boron nitride/polymethylmethacrylate(BN/PMMA, B) and graphene nanosheets(GNS/PMMA, G) compound solutions. The structure, morphology, thermal conductivity, and particularly the dielectric and relaxation behaviors were systematically studied. Results showed that a good exfoliation and dispersion of BN and GNS can be simply achieved through intensive mechanical compounding with PMMA in the internal mixer. The dielectric constant and breakdown strength of the obtained 1-3-1(B-G-B) sandwich composite film reached 4.3(@1 kHz) and 458.6kV/mm, being 119 % and 113 % higher than that of pure PMMA, respectively. Furthermore, the overall thermal conductivity of sandwich 1-3-1 composite increased by 112 % due to the addition of thermally conductive BN and GNS. The sandwich design strategy provided an effective way of achieving good permittivity, high insulation, and improved thermal conductivity simultaneously, showing potential applications in the miniaturization and integration of electronic devices.

关键词： Sandwich structure breakdown strength Thermal conductivity Dielectric constant Composites

Constructing nanocomposites with robust covalent connection between nanoparticles and polymer for high discharged energy density and excellent tensile properties

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Journal of Energy Chemistry 2022年第5期31卷 195-205页

作者： Jiachen Ma Yabin Zhang Yan Zhang Luqing Zhang Shuxiang Zhang Xuchuan Jiang Hong Liu Shandong Provincial Key Laboratory of Fluorine Chemistry and Chemical Materials School of Chemistry and Chemical EngineeringUniversity of JinanJinan 250022ShandongChina Institute for Advanced Interdisciplinary Research University of JinanJinan 250022ShandongChina State Key Laboratory of Crystal Materials Shandong UniversityJinan 250100ShandongChina Institute for Smart Materials&Engineering University of JinanJinan 250022ShandongChina

High discharged energy density and excellent flexible properties in dielectric materials are significantly sought to meet the rapid advancements in the electronics industry. In this study, covalent bonds are constructed between poly(vinylidene fluoride-chlorotrifluoroethylene), which contains olefinic bonds, and thiol-modified BaTiO_(3) at the interface before the nanocomposite films are fabricated. The presence of the covalent bonds is proved to promote the dispersibility of the modified BaTiO_(3) and enhance the interfacial adhesion between the modified BaTiO_(3) and the polymer, followed by a remarkably positive effect in suppressing the dielectric loss(tanδ) and increasing the breakdown strength(Eb) of the nanocomposite films. In addition, the cross-linking treatment in the preparation process is found to be favourable for improving the mechanical properties of the nanocomposite films, which benefits the enhancement of Eb. Furthermore, at 400% elongation, the stretched nanocomposite film doped with 5 vol% modified BaTiO_(3) exhibits an Eb15.6% greater than that of the unstretched film, and the discharged energy density reaches 11.4 J/cm^(3) with a high discharge energy efficiency of 84.5%. This study provides a novel strategy for preparing flexible nanocomposites with powerful interfacial adhesion at high filler content to achieve high discharged energy density.

关键词： Dielectric materials Energy density Mechanical properties Interfacial adhesion breakdown strength

Tunable polarization-drived superior energy storage performance in PbZrO_(3) thin films

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Journal of Advanced Ceramics 2023年第5期12卷 930-942页

作者： Tiandong Zhang Zhuangzhuang Shi Chao Yin Changhai Zhang Yue Zhang Yongquan Zhang Qingguo Chen Qingguo Chi Key Laboratory of Engineering Dielectrics and Its Application Ministry of EducationHarbin University of Science and TechnologyHarbin 150080China Department of Materials Science and Engineering Korea Advanced Institute of Science and TechnologyDaejeon 305-701Republic of Korea

Antiferroelectric PbZrO_(3)(AFE PZO)films have great potential to be used as the energy storage dielectrics due to the unique electric field(E)-induced phase transition ***,the phase transition process always accompanies a polarization(P)hysteresis effect that induces the large energy loss(Wloss)and lowers the breakdown strength(EBDS),leading to the inferior energy storage density(Wrec)as well as low *** this work,the synergistic strategies by doping smaller ions of Li^(+)–Al^(3+)to substitute Pb2+and lowering the annealing temperature(T)from 700 to 550℃are proposed to change the microstructures and tune the polarization characters of PZO films,except to dramatically improve the energy storage *** prepared Pb_((1−x))(Li_(0.5)Al_(0.5))_(x)ZrO_(3)(P_((1−x))(L_(0.5)A_(0.5))_(x)ZO)films exhibit ferroelectric(FE)-like rather than AFE character once the doping content of Li^(+)–Al^(3+)ions reaches 6 mol%,accompanying a significant improvement of W_(rec) of 49.09 J/cm^(3),but the energy storage efficiency(η)is only 47.94%due to the long-correlation of FE ***,the low-temperature annealing is carried out to reduce the crystalline degree and the P loss.P_(0.94)(L_(0.5)A_(0.5))_(0.06)ZO films annealed at 550℃deliver a linear-like polarization behavior rather than FE-like behavior annealed at 700℃,and the lowered remanent polarization(P_(r))as well as improved E_(BDS)(4814 kV/cm)results in the superior Wrec of 58.7 J/cm^(3) and efficiency of 79.16%,simultaneously possessing excellent frequency and temperature stability and good electric fatigue tolerance.

关键词： lead zirconate ionic pair polarization breakdown strength energy storage

Fabrication of large area hexagonal boron nitride thin films for bendable capacitors

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Nano Research 2013年第8期6卷 602-610页

作者： Ning Guo Jinquan Wei Yi Jia Huanhuan Sun Yuhang Wang Kehan Zhao Xiaolan Shi Liuwan Zhang Xinming Li Anyuan Cao Hongwei Zhu Kunlin Wang Dehai Wu Key Lab for Advanced Materials Processing Technology of Education Ministry School of Materials Science and Engineering Tsinghua University Beijing 100084 China Department of Physics Tsinghua University Beijing 100084 China Department of Materials Science and Engineering College of Engineering Peking University Beijing 100871 China

Highly reliable and bendable dielectrics are desired in flexible or bendable electronic devices for future applications. Hexagonal boron nitride （h-BN） can be used as bendable dielectric due to its wide band gap. Here, we fabricate high quality h-BN films with controllable thickness by a low pressure chemical vapor deposition method. We demonstrate a parallel-plate capacitor using h-BN film as the dielectric. The h-BN capacitors are reliable with a high breakdown field strength of -9.0 MV/cm. Tunneling current across the h-BN film is inversely exponential to the thickness of dielectric, which makes the capacitance drop significantly. The h-BN capacitor shows a best specific capacitance of 6.8 F/cm^2, which is one order of magnitude higher than the calculated value.

关键词： hexagonal boron nitride capacitor breakdown strength tunneling effect

Optimizing the grain size and grain boundary morphology of (K,Na) NbO_(3)-based ceramics: Paving the way for ultrahigh energy storage capacitors

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Journal of Materiomics 2021年第4期7卷 780-789页

作者： Xiaozhi Wang Yu Huan Peiyao Zhao Xiaoming Liu Tao Wei Qiwen Zhang Xiaohui Wang School of Material Science and Engineering University of JinanJinan250022China State Key Laboratory of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing100084China Key Laboratory of Electromagnetic Processing of Materials(Ministry of Education) Northeastern UniversityShenyang110819China The Chinese Ceramic Society Beijing100831China

Relaxor dielectric ceramic capacitors are very attractive for high-power energy ***,the low breakdown strength severely restricts improvements to the energy storage density and practical ***,a strategy of designing small grain sizes and abundant amorphous grain boundaries is proposed to improve the energy storage properties under the guidance of phase field theory.0.925(K_(0.5)Na_(0.5))NbO_(3)-e0.075Bi(Zn_(2/3)(Ta_(0.5)Nb_(0.5))1/3)O_(3)(KNNe-BZTN)relaxor ferroelectric ceramic is taken as an example to verify our *** grain sizes and grain boundaries of the KNNeBZTN ceramics are carefully controlled by the high-energy ball milling method and twoestep sintering *** analysis and diffusion reflectance spectra demonstrate that KNNeBZTN ceramics with a small grain size and abundant amorphous grain boundary exhibit a lower charge carrier concentration and higher band *** a consequence,the breakdown electric field of KNNeBZTN ceramics increases from 222 kV/cm to 317 kV/cm when the grain size is decreased from 410 nm to 200 nm,accompanied by a slightly degraded maximum *** ceramics with an average grain size of~250 nm and abundant amorphous grain boundaries exhibit optimum energy storage properties with a high recoverable energy density of 4.02 J/cm^(3) and a high energy efficiency of 87.4%.This successful local structural design opens up a new paradigm to improve the energy storage performance of other dielectric ceramic capacitors for electrical energy storage.

关键词： Grain size Grain boundary KNN-based dielectric ceramic capacitors Energy storage properties breakdown strength Two-step sintering strategy

Improved energy storage performance of nanocomposites with Bi_(4.2)K_(0.8)Fe_(2)O_(9+δ) nanobelts

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Journal of Materiomics 2020年第2期6卷 371-376页

作者： Chuangming Hou Zhiwei Bao Haoyang Sun Yuewei Yin Xiaoguang Li Hefei National Laboratory for Physical Sciences at the Microscale Department of Physicsand CAS Key Laboratory of Strongly-coupled Quantum Matter PhysicsUniversity of Science and Technology of ChinaHefei230026China School of Physics and Materials Science Anhui UniversityHefei230601China Collaborative Innovation Center of Advanced Microstructures Nanjing210093China

Modern electronics and electric power grids require high performance polymer-based dielectric *** realize large-scale applications,the energy density of nanocomposites needs to be further ***,we demonstrate a remarkable improvement in energy density of poly(vinylidene fluoride)(PVDF)matrix upon the incorporation of high-k Bi_(4.2)K_(0.8)Fe_(2)O_(9+δ)(BKFO)*** aspect ratio BKFO nanobelts can enhance the Young's moduli of the nanocomposites and increase the path tortuosity of electrical trees,which are favorable for increasing the breakdown strength of the ***,the dielectric constant and breakdown strength increase simultaneously at a low volume fraction(0.35 vol%)of BKFO nanobelts,and an ultrahigh recoverable energy density of 25.4 J/cm^(3) is *** results provide a strategy to develop high performance flexible high-energy-density devices.

关键词： Dielectric nanocomposite Energy storage Nanobelt breakdown strength

ANN approaches to determine the dielectric strength improvement of MgO based low density polyethylene nanocomposite

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Journal of Advanced Dielectrics 2021年第4期11卷 27-36页

作者： Sherif Haggag Loai Nasrat Hanafy Ismail Faculty of Engineering Department of Power and Machines Ain Shams UniversityCairoEgypt Faculty of Engineering Department of Electrical Engineering Aswan University AswanEgypt

This paper presents the modification occurred to the dielectric strength feature of low density polyethylene compounded with nano magnesia(LDPE/MgO).MgO nanoparticles were prepared using sol-gel technique,MgO filler surface was functionalized to improve the interfacial ***’s groups of composites with different filler concentrations were fabricated by mix blend *** exposed to various salinity media by immersion,dielectric strength test was applied on each set according to relevant ASTM standard with identical testing *** results were statistically processed then compared to the pristine *** results utilized to learn Artificial Neural Network in order to acquire the value of dielectric strength of compounds having similar composition but containing different doping amounts or influenced with various salinity level *** dielectric strength is enhanced by the addition of MgO *** the investigation of the obtained results,it is concluded that additives of 1.4%filler concentration by weight is the optimum MgO content for LDPE/MgO nanofiller *** think that this paper may promote a good researching methodology that gather both empirical work and numerical tools in this field.

关键词： Polymer nanocomposites salinity surface treatment breakdown strength artificial neural network

breakdown Property of LDPE Silica Nanocomposite Used in HVDC Cable Insulation

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Breakdown Property of LDPE Silica Nanocomposite Used in HVDC...

Tuning ferroelectricity of polymer blends for flexible electrical energy storage applications

作者： LAN Li YIN Yi PANG Aili FEI Fei LI Yinong

The breakdown strength of polymer nanocomposite is related to the properties of nano-additive,such as doping concentration,particle size and surface *** this paper,LDPE/silica nanocomposite with different doping concentration,particle size and particle surface treatment were made to test the breakdown strength under AC,positive DC and negative DC voltage,*** concentration of nanosilica is 0.1%,0.5% and 2.0%,*** average particle size is from 7 nm to 16 *** hydrophobic and hydrophilic treated particles were *** results show that doping nanosilica can improve the breakdown strength of *** breakdown strength increased with the increasing of doping *** the same concentration,the breakdown strength of LDPE/silica nanocomposite decreased with the increasing of particle ***,in the case of small particle size（7 nm）,the smaller shape parameter indicated the aggregation of nanosilica particles,which led to the drop of the breakdown *** surface treatment of nanosilica enhanced the breakdown strength of LDPE/silica nanocomposite.

关键词： nanocomposite breakdown strength Weibull distribution concentration surface treatment

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Science China Materials 2021年第7期64卷 1642-1652页

作者： Xin Zhang Yanda Jiang Ruoqi Gao Xinhui Li Zhonghui Shen Bao-Wen Li Qingfeng Zhang Shujun Zhang Ce-Wen Nan State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Center of Smart Materials and DevicesWuhan University of TechnologyWuhan 430070China International School of Materials Science and Engineering Wuhan University of TechnologyWuhan 430070China Hubei Key Lab of Ferro&Piezoelectric Materials and Devices School of Materials Science&EngineeringHubei UniversityWuhan 430062China Institute for Superconducting and Electronic Materials Australian Institute of Innovative MaterialsUniversity of WollongongNorth WollongongNSW 2500Australia School of Materials Science and Engineering State Key Lab of New Ceramics and Fine ProcessingTsinghua UniversityBeijing 100084China

Ferroelectric polymers are the mainstay of advanced flexible electronic *** to tailor the ferroelectric polymer films for various applications via simple processing approaches is *** we demonstrate the tuning of ferroelectric responses can be achieved in polymer blends of poly(vinylidene fluoride-trifluoroethylene)(P(VDF-TrFE))and polymethyl methacrylate(PMMA)prepared via a simple two-step *** proposed two-step process endows the polymer blends with a random distribution of P(VDF-TrFE)crystalline phase,hence decoupling the coherent ferroelectric domain interactions between continuous ordered crystalline phases that ubiquitously existed in common P(VDF-TrFE)*** incorporation of the miscible non-crystalline PMMA chains with low-polarity results in reversal dipoles and a transition from ferroelectric to antiferroelectric-like behavior,overcoming the trade-off between the polarization and depolarization *** particular,resultant excellent mechanical and electrical properties of the polymer blend films give rise to remarkably improved breakdown strength and energy storage performance,surpassing P(VDF-TrFE)and commercial biaxial-oriented polypropylene *** work provides a simple and effective strategy to tailor the ferroelectric response of polymeric materials with great potential for flexible electrical energy storage applications.

关键词： ferroelectric polymers antiferroelectricity energy density breakdown strength dielectric

Enhanced energy storage properties of barium titanate ceramics made from surface modified particles

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Journal of Advanced Dielectrics 2013年第3期3卷 36-42页

作者： Zhifu Liu Zhiqiang Zhang Faqiang Zhang Yongxiang Li CAS Key Lab.of Inorganic Functional Materials and Devices Shanghai Institute of Ceramics Chinese Academy of Sciences No.1295 Dingxi RoadShanghai 200050P.R.China

Surface modification of barium titanate particles has been carried out using a wet chemical *** microstructural and dielectric properties of the ceramics made from surface modified particles were extensively investigated by X-ray diffraction,scanning electron microscopy,transmission electron microscopy,and dielectric properties *** breakdown strength increased by 69%and 117%for the Al_(2)O_(3) and B_(2)O_(3)–SiO_(2) modified ceramics,*** energy storage density of up to 3.2 J/cm^(3) has been *** suppression of grain boundary electron transport and reduction in pore defects lead to the energy storage properties enhancement of the modified *** results indicated that surface modification of ceramic particles is a promising approach to obtain dielectric ceramics with high energy storage density.

关键词： Barium titanate energy storage surface modification breakdown strength