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High energy density in ultra-thick and flexible electrodes enabled by designed conductive agent/binder composite
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作者 Xiaoyu Shen Hailong Yu +6 位作者 Liubin Ben Wenwu Zhao Qiyu Wang Guanjun Cen Ronghan Qiao Yida Wu Xuejie Huang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第3期133-143,I0005,共12页
Thick electrodes can increase incorporation of active electrode materials by diminishing the proportion of inactive constituents,improving the overall energy density of batteries.However,thick electrodes fabricated us... Thick electrodes can increase incorporation of active electrode materials by diminishing the proportion of inactive constituents,improving the overall energy density of batteries.However,thick electrodes fabricated using the conventional slurry casting approach frequently exhibit an exacerbated accumulation of carbon additives and binders on their surfaces,invariably leading to compromised electrochemical properties.In this study,we introduce a designed conductive agent/binder composite synthesized from carbon nanotube and polytetrafluoroethylene.This agent/binder composite facilitates production of dry-process-prepared ultra-thick electrodes endowed with a three-dimensional and uniformly distributed percolative architecture,ensuring superior electronic conductivity and remarkable mechanical resilience.Using this approach,ultra-thick LiCoO_(2)(LCO) electrodes demonstrated superior cycling performance and rate capabilities,registering an impressive loading capacity of up to 101.4 mg/cm^(2),signifying a 242% increase in battery energy density.In another analytical endeavor,time-of-flight secondary ion mass spectroscopy was used to clarify the distribution of cathode electrolyte interphase(CEI) in cycled LCO electrodes.The results provide unprecedented evidence explaining the intricate correlation between CEI generation and carbon distribution,highlighting the intrinsic advantages of the proposed dry-process approach in fine-tu ning the CEI,with excellent cycling performance in batteries equipped with ultra-thick electrodes. 展开更多
关键词 conductive agent/binder composite Dry process Ultra-thick electrodes High energy density CEI reconstruction ToF-SIMS
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Boron nitride silicone rubber composite foam with low dielectric and high thermal conductivity
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作者 Shuilai Qiu Hang Wu +1 位作者 Fukai Chu Lei Song 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第4期224-230,共7页
Silicone rubber(SR)is widely used in the field of electronic packaging because of its low dielectric properties.In this work,the porosity of the SR was improved,and the dielectric constant of the SR foam was reduced b... Silicone rubber(SR)is widely used in the field of electronic packaging because of its low dielectric properties.In this work,the porosity of the SR was improved,and the dielectric constant of the SR foam was reduced by adding expanded microspheres(EM).Then,the thermal conductivity of the system was improved by combining the modified boron nitride(f-BN).The results showed that after the f-BN was added,the dielectric constant and dielectric loss were much lower than those of pure SR.Micron-sized modified boron nitride(f-mBN)improved the dielectric and thermal conductivity of the SR foam better than that of nano-sized modified boron nitride(f-nBN),but f-nBN improved the volume resistivity,tensile strength,and thermal stability of the SR better than f-mBN.When the mass ratio of f-mBN and fnBN is 2:1,the thermal conductivity of the SR foam reaches the maximum value of 0.808 W·m^(-1)·K^(-1),which is 6.5 times that before the addition.The heat release rate and fire growth index are the lowest,and the improvement in flame retardancy is mainly attributed to the high thermal stability and physical barrier of f-BN. 展开更多
关键词 Foam compositeS Dielectric properties Thermal conductivity Mechanical properties Flame retardant
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Supposition of graphene stacks to estimate the contact resistance and conductivity of nanocomposites
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作者 Y.ZARE M.T.MUNIR +1 位作者 G.J.WENG K.Y.RHEE 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第4期663-676,共14页
In this study,the effects of stacked nanosheets and the surrounding interphase zone on the resistance of the contact region between nanosheets and the tunneling conductivity of samples are evaluated with developed equ... In this study,the effects of stacked nanosheets and the surrounding interphase zone on the resistance of the contact region between nanosheets and the tunneling conductivity of samples are evaluated with developed equations superior to those previously reported.The contact resistance and nanocomposite conductivity are modeled by several influencing factors,including stack properties,interphase depth,tunneling size,and contact diameter.The developed model's accuracy is verified through numerous experimental measurements.To further validate the models and establish correlations between parameters,the effects of all the variables on contact resistance and nanocomposite conductivity are analyzed.Notably,the contact resistance is primarily dependent on the polymer tunnel resistivity,contact area,and tunneling size.The dimensions of the graphene nanosheets significantly influence the conductivity,which ranges from 0 S/m to90 S/m.An increased number of nanosheets in stacks and a larger gap between them enhance the nanocomposite's conductivity.Furthermore,the thicker interphase and smaller tunneling size can lead to higher sample conductivity due to their optimistic effects on the percolation threshold and network efficacy. 展开更多
关键词 graphene polymer composite stacked nanosheet tunneling conductivity contact resistance INTERPHASE
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3D-printable Boron Nitride/Polyacrylic Hydrogel Composites with High Thermal Conductivities
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作者 DAI Jialei XUE Bingyu +5 位作者 QIAN Qi HE Wenhao ZHU Chenglong LEI Liwen WANG Kun XIE Jingjing 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第5期1303-1310,共8页
Polyacrylic acid(PAA)hydrogel composites with different hexagonal boron nitride(h-BN)fillers were synthesized and successfully 3D-printed while their thermal conductivity was systematically studied.With the content of... Polyacrylic acid(PAA)hydrogel composites with different hexagonal boron nitride(h-BN)fillers were synthesized and successfully 3D-printed while their thermal conductivity was systematically studied.With the content of h-BN increasing from 0.1 wt%to 0.3 wt%,the thermal conductivity of the 3D-printed composites has been improved.Moreover,through the shear force given by the 3D printer,a complete thermal conductivity path is obtained inside the hydrogel,which significantly improves the thermal conductivity of the h-BN hydrogel composites.The maximum thermal conductivity is 0.8808 W/(m·K),leading to a thermal conductive enhancement of 1000%,compared with the thermal conductivity of pure PAA hydrogels.This study shows that using h-BN fillers can effectively and significantly improve the thermal conductivity of hydrogelbased materials while its 3D-printable ability has been maintained. 展开更多
关键词 hydrogel composites boron nitride 3D printing thermal conductivity
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Multi-scale Modeling and Finite Element Analyses of Thermal Conductivity of 3D C/SiC Composites Fabricating by Flexible-Oriented Woven Process
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作者 Zheng Sun Zhongde Shan +5 位作者 Hao Huang Dong Wang Wang Wang Jiale Liu Chenchen Tan Chaozhong Chen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2024年第3期275-288,共14页
Thermal conductivity is one of the most significant criterion of three-dimensional carbon fiber-reinforced SiC matrix composites(3D C/SiC).Represent volume element(RVE)models of microscale,void/matrix and mesoscale pr... Thermal conductivity is one of the most significant criterion of three-dimensional carbon fiber-reinforced SiC matrix composites(3D C/SiC).Represent volume element(RVE)models of microscale,void/matrix and mesoscale proposed in this work are used to simulate the thermal conductivity behaviors of the 3D C/SiC composites.An entirely new process is introduced to weave the preform with three-dimensional orthogonal architecture.The 3D steady-state analysis step is created for assessing the thermal conductivity behaviors of the composites by applying periodic temperature boundary conditions.Three RVE models of cuboid,hexagonal and fiber random distribution are respectively developed to comparatively study the influence of fiber package pattern on the thermal conductivities at the microscale.Besides,the effect of void morphology on the thermal conductivity of the matrix is analyzed by the void/matrix models.The prediction results at the mesoscale correspond closely to the experimental values.The effect of the porosities and fiber volume fractions on the thermal conductivities is also taken into consideration.The multi-scale models mentioned in this paper can be used to predict the thermal conductivity behaviors of other composites with complex structures. 展开更多
关键词 3D C/SiC composites Finite element analyses Multi-scale modeling Thermal conductivity
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Outstanding proton conductivity over wide temperature and humidity ranges and enhanced mechanical, thermal stabilities for surface-modified MIL-101-Cr-NH2/Nafion composite membranes
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作者 Xu Li Dongwei Zhang +7 位作者 Si Chen Yingzhao Geng Yong Liu Libing Qian Xi Chen Jingjing Li Pengfei Fang Chunqing He 《Green Energy & Environment》 SCIE EI CAS CSCD 2024年第11期1734-1746,共13页
High-performance proton exchange membranes are of great importance for fuel cells.Here,we have synthesized polycarboxylate plasticizer modified MIL-101-Cr-NH2(PCP-MCN),a kind of hybrid metal-organic framework,which exh... High-performance proton exchange membranes are of great importance for fuel cells.Here,we have synthesized polycarboxylate plasticizer modified MIL-101-Cr-NH2(PCP-MCN),a kind of hybrid metal-organic framework,which exhibits a superior proton conductivity.PCP-MCN nanoparticles are used as additives to fabricate PCP-MCN/Nafion composite membranes.Microstructures and characteristics of PCP-MCN and these membranes have been extensively investigated.Significant enhancement in proton conduction for PCP-MCN around 55℃ is interestingly found due to the thermal motion of the PCP molecular chains.Robust mechanical properties and higher thermal decomposition temperature of the composite membranes are directly ascribed to strong intermolecular interactions between PCP-MCN and Nafion side chains,i.e.,the formation of substantial acid–base pairs(-SO_(3)^(-)…^(+)H–NH-),which further improves compatibility between additive and Nafion matrix.At the same humidity and temperature condition,the water uptake of composite membranes significantly increases due to the incorporation of porous additives with abundant functional groups and thus less crystallinity degree in comparison to pristine Nafion.Proton conductivity(σ)over wide ranges of humidities(30-100%RH at 25℃)and temperatures(30-98℃ at 100%RH)for prepared membranes is measured.The s in PCPMCN/Nafion composite membranes is remarkably enhanced,i.e.0.245 S/cm for PCP-MCN-3wt.%/Nafion is twice that of Nafion membrane at 98℃ and 100%RH,because of the establishment of well-interconnected proton transport ionic water channels and perhaps faster protonation–deprotonation processes.The composite membranes possess weak humidity-dependence of proton transport and higher water uptake due to excellent water retention ability of PCP-MCN.In particular,when 3 wt.%PCP-MCN was added to Nafion,the power density of a single-cell fabricated with this composite membrane reaches impressively 0.480,1.098 W/cm^(2) under 40%RH,100%RH at 60℃,respectively,guaranteeing it to be a promising proton exchange membrane. 展开更多
关键词 Nafion composite membrane Surface-modified MIL-101-Cr-NH2 Proton conductivity Single-cell performance
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Galerkin-based quasi-smooth manifold element(QSME)method for anisotropic heat conduction problems in composites with complex geometry
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作者 Pan WANG Xiangcheng HAN +2 位作者 Weibin WEN Baolin WANG Jun LIANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第1期137-154,共18页
The accurate and efficient analysis of anisotropic heat conduction problems in complex composites is crucial for structural design and performance evaluation. Traditional numerical methods, such as the finite element ... The accurate and efficient analysis of anisotropic heat conduction problems in complex composites is crucial for structural design and performance evaluation. Traditional numerical methods, such as the finite element method(FEM), often face a trade-off between calculation accuracy and efficiency. In this paper, we propose a quasi-smooth manifold element(QSME) method to address this challenge, and provide the accurate and efficient analysis of two-dimensional(2D) anisotropic heat conduction problems in composites with complex geometry. The QSME approach achieves high calculation precision by a high-order local approximation that ensures the first-order derivative continuity.The results demonstrate that the QSME method is robust and stable, offering both high accuracy and efficiency in the heat conduction analysis. With the same degrees of freedom(DOFs), the QSME method can achieve at least an order of magnitude higher calculation accuracy than the traditional FEM. Additionally, under the same level of calculation error, the QSME method requires 10 times fewer DOFs than the traditional FEM. The versatility of the proposed QSME method extends beyond anisotropic heat conduction problems in complex composites. The proposed QSME method can also be applied to other problems, including fluid flows, mechanical analyses, and other multi-field coupled problems, providing accurate and efficient numerical simulations. 展开更多
关键词 anisotropic heat conduction quasi-smooth manifold element(QSME) composite with complex geometry numerical simulation finite element method(FEM)
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Flexible Polydimethylsiloxane Composite with Multi-Scale Conductive Network for Ultra-Strong Electromagnetic Interference Protection 被引量:8
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作者 Jie Li He Sun +5 位作者 Shuang-Qin Yi Kang-Kang Zou Dan Zhang Gan-Ji Zhong Ding-Xiang Yan Zhong-Ming Li 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第1期293-306,共14页
Highly conductive polymer composites(CPCs) with excellent mechanical flexibility are ideal materials for designing excellent electromagnetic interference(EMI) shielding materials,which can be used for the electromagne... Highly conductive polymer composites(CPCs) with excellent mechanical flexibility are ideal materials for designing excellent electromagnetic interference(EMI) shielding materials,which can be used for the electromagnetic interference protection of flexible electronic devices.It is extremely urgent to fabricate ultra-strong EMI shielding CPCs with efficient conductive networks.In this paper,a novel silver-plated polylactide short fiber(Ag@PL ASF,AAF) was fabricated and was integrated with carbon nanotubes(CNT) to construct a multi-scale conductive network in polydimethylsiloxane(PDMS) matrix.The multi-scale conductive network endowed the flexible PDMS/AAF/CNT composite with excellent electrical conductivity of 440 S m-1and ultra-strong EMI shielding effectiveness(EMI SE) of up to 113 dB,containing only 5.0 vol% of AAF and 3.0 vol% of CNT(11.1wt% conductive filler content).Due to its excellent flexibility,the composite still showed 94% and 90% retention rates of EMI SE even after subjected to a simulated aging strategy(60℃ for 7 days) and 10,000 bending-releasing cycles.This strategy provides an important guidance for designing excellent EMI shielding materials to protect the workspace,environment and sensitive circuits against radiation for flexible electronic devices. 展开更多
关键词 Flexible conductive polymer composites Silver-plated polylactide short fiber Carbon nanotube Electromagnetic interference shielding Multi-scale conductive network
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Effects of Conductive Carbon Black on Thermal and Electrical Properties of Barium Titanate/Polyvinylidene Fluoride Composites for Road Application
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作者 Zhenguo Wang Lenan Wang +2 位作者 Yejing Meng Yong Wen Jianzhong Pei 《Journal of Renewable Materials》 SCIE EI 2023年第5期2469-2489,共21页
In the field of roads,due to the effect of vehicle loads,piezoelectric materials under the road surface can convert mechanical vibration into electrical energy,which can be further used in road facilities such as traf... In the field of roads,due to the effect of vehicle loads,piezoelectric materials under the road surface can convert mechanical vibration into electrical energy,which can be further used in road facilities such as traffic signals and street lamps.The barium titanate/polyvinylidene fluoride(BaTiO_(3)/PVDF)composite,the most common hybrid ceramic-polymer system,was widely used in various fields because the composite combines the good dielectric property of ceramic materials with the good flexibility of PVDF material.Previous studies have found that conductive particles can further improve the dielectric and piezoelectric properties of other composites.However,few studies have investigated the effect of conductive carbon black on the dielectric and piezoelectric properties of BaTiO_(3)/PVDF composites.In this study,BaTiO_(3)/PVDF/conductive carbon black composites were prepared with various conductive carbon black contents based on the optimum ratio of BaTiO_(3)to PVDF.The effects of conductive carbon black content on the morphologies,thermal performance,conductivities,dielectric properties,and piezoelectric properties of the BaTiO_(3)/PVDF/conductive carbon black composites were then investigated.The addition of conductive carbon black greatly enhances the conductivities,dielectric properties,and piezoelectric properties of the BaTiO_(3)/PVDF/conductive carbon black composites,especially when the carbon black content is 0.8%by weight of PVDF.Additionally,the conductive carbon black does not have an obvious effect on the morphologies and thermal stabilities of BaTiO_(3)/PVDF/conductive carbon black composites. 展开更多
关键词 Dielectric property piezoelectric property conductIVITY thermal stability BaTiO_(3)/PVDF composites conductive carbon black
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Wearable and stretchable conductive polymer composites for strain sensors:How to design a superior one?
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作者 Liwei Lin Sumin Park +6 位作者 Yuri Kim Minjun Bae Jeongyeon Lee Wang Zhang Jiefeng Gao Sun Ha Paek Yuanzhe Piao 《Nano Materials Science》 EI CAS CSCD 2023年第4期392-403,共12页
Wearable and stretchable strain sensors have potential values in the fields of human motion and health monitoring,flexible electronics,and soft robotic skin.The wearable and stretchable strain sensors can be directly ... Wearable and stretchable strain sensors have potential values in the fields of human motion and health monitoring,flexible electronics,and soft robotic skin.The wearable and stretchable strain sensors can be directly attached to human skin,providing visualized detection for human motions and personal healthcare.Conductive polymer composites(CPC)composed of conductive fillers and flexible polymers have the advantages of high stretchability,good flexibility,superior durability,which can be used to prepare flexible strain sensors with large working strain and outstanding sensitivity.This review has put forward a comprehensive summary on the fabrication methods,advanced mechanisms and strain sensing abilities of CPC strain sensors reported in recent years,especially the sensors with superior performance.Finally,the structural design,bionic function,integration technology and further application of CPC strain sensors are prospected. 展开更多
关键词 Wearable strain sensors conductive polymer composites MECHANISM Sensing performance
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Effects of carbonaceous conductive fillers on electrical and thermal properties of asphalt-matrix conductive composites
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作者 周晓锋 张小松 周建成 《Journal of Southeast University(English Edition)》 EI CAS 2013年第1期88-91,共4页
The relationship between thermal/electrical conductivity enhancement in asphalt-matrix mixtures and the properties of filling conductive particles is studied. The thermal properties with filling the carbon fiber, grap... The relationship between thermal/electrical conductivity enhancement in asphalt-matrix mixtures and the properties of filling conductive particles is studied. The thermal properties with filling the carbon fiber, graphite conductive particles in asphalt-matrix mixtures are investigated. Based on the generalized effective medium theory ( EMT ), the effective thermal and electrical conductivity of carbon fiber/asphalt and graphite/asphalt composites are theoretically elucidated. The theoretical results are found to be in reasonably well agreement with the experimental data. Moreover, the theoretical and experimental results show that the large-aspect-ratio shape of particles can help to achieve a large enhancement of effective conductivity, and the use of disk-like high conductivity particles can limit the additive contents for preserving the volumetric properties and mechanical properties of asphalt composites. The generalized effective medium theory model can be used for predicting the thermal and electrical properties of asphaltmatrix composites, which is still available for most of the thermal/electrical modifications in two-phase composites. 展开更多
关键词 carbonaceous conductive fillers asphalt-matrix composites thermal conductivity electrical conductivity
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Numerical study of directional heat transfer in composite materials via controllable carbon fiber distribution
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作者 SHI Lei HUANG Cun-wen +5 位作者 YE Jian-ling WEN Shuang LIU Su-ping LI Fen-qiang ZHOU Tian SUN Zhi-qiang 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第6期1945-1955,共11页
Carbon fiber reinforced polyamide 12(CF/PA12),a new material renowned for its excellent mechanical and thermal properties,has drawn significant industry attention.Using the steady-state research to heat transfer,a ser... Carbon fiber reinforced polyamide 12(CF/PA12),a new material renowned for its excellent mechanical and thermal properties,has drawn significant industry attention.Using the steady-state research to heat transfer,a series of simulations to investigate the heat transfer properties of CF/PA12 were conducted in this study.Firstly,by building two-and three-dimensional models,the effects of the porosity,carbon fiber content,and arrangement on the heat transfer of CF/PA12 were examined.A validation of the simulation model was carried out and the findings were consistent with those of the experiment.Then,the simulation results using the above models showed that within the volume fraction from 0% to 28%,the thermal conductivity of CF/PA12 increased greatly from 0.0242 W/(m·K)to 10.8848 W/(m·K).The increasing porosity had little influence on heat transfer characteristic of CF/PA12.The direction of the carbon fiber arrangement affects the heat transfer impact,and optimal outcomes were achieved when the heat flow direction was parallel to the carbon fiber.This research contributes to improving the production methods and broadening the application scenarios of composite materials. 展开更多
关键词 heat transfer thermal conductivity carbon fiber-based composite
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Microstructure and properties of Cu matrix composites reinforced with surface-modified Kovar particles
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作者 Tao MENG Ri-chu WANG +1 位作者 Zhi-yong CAI Ying-jun YAO 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2024年第10期3251-3264,共14页
The thermal conductivity of Cu/Kovar composites was improved by suppressing element diffusion at the interfaces through the formation of FeWO_(4)coating on the Kovar particles via vacuum deposition.Cu matrix composite... The thermal conductivity of Cu/Kovar composites was improved by suppressing element diffusion at the interfaces through the formation of FeWO_(4)coating on the Kovar particles via vacuum deposition.Cu matrix composites reinforced with unmodified(Cu/Kovar)and modified Kovar(Cu/Kovar@)particles were prepared by hot pressing.The results demonstrate that the interfaces of Cu/FeWO_(4)and FeWO_(4)/Kovar in the Cu/Kovar@composites exhibit strong bonding,and no secondary phase is generated.The presence of FeWO_(4)impedes interfacial diffusion within the composite,resulting in an increase in grain size and a decrease in dislocation density.After surface modification of the Kovar particle,the thermal conductivity of Cu/Kovar@composite is increased by 110%from 40.6 to 85.6 W·m^(-1)·K^(-1).Moreover,the thermal expansion coefficient of the Cu/Kovar@composite is 9.8×10^(-6)K^(-1),meeting the electronic packaging requirements. 展开更多
关键词 electronic packaging material Cu/Kovar composite surface modification thermal conductivity
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Revealing the specific role of sulfide and nano-alumina in composite solid-state electrolytes for performance-reinforced ether-nitrile copolymers
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作者 Haoyang Yuan Changhao Tian +3 位作者 Mengyuan Song Wenjun Lin Tao Huang Aishui Yu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第4期628-636,共9页
Composite solid-state electrolytes represent a critical pathway that balances the interface compatibility and lithium-ion conductivity in all-solid-state batteries.The quest for stable and highly ion-conductive combin... Composite solid-state electrolytes represent a critical pathway that balances the interface compatibility and lithium-ion conductivity in all-solid-state batteries.The quest for stable and highly ion-conductive combinations between polymers and fillers is vital,but blind attempts are often made due to a lack of understanding of the mechanisms involved in the interaction between polymers and fillers.Herein,we employ in-situ polymerization to prepare a polymer based on an ether-nitrile copolymer with high cathode stability as the foundation and discuss the performance enhancement mechanisms of argyrodite and nano-alumina.With 1%content of sulfide interacting with the polymer at the two-phase interface,the local enhancement of lithium-ion migration capability can be achieved,avoiding the reduction in capacity due to the low ion conductivity of the passivation layer during cycling.The capacity retention after 50cycles at 0.5 C increases from 83.5%to 94.4%.Nano-alumina,through anchoring the anions and interface inhibition functions,eventually poses an initial discharge capacity of 136.8 m A h g^(-1)at 0.5 C and extends the cycling time to 1000 h without short-circuiting in lithium metal batteries.Through the combined action of dual fillers on the composite solid-state electrolyte,promising insights are provided for future material design. 展开更多
关键词 composite solid-state electrolytes Lithium metal anode Dual fillers Interfacial ionic conduction Inert nano-alumina
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Effects of diamond particle size on microstructure and properties of diamond/Al-12Si composites prepared by vacuum-assisted pressure infiltration
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作者 Jia-ping Fu Can-xu Zhou +1 位作者 Guo-fa Mi Yuan Liu 《China Foundry》 SCIE EI CAS CSCD 2024年第4期360-368,共9页
Diamond/aluminium composites have attracted attention in the field of thermal management of electronic packaging for their excellent properties.In order to solve the interfacial problem between diamond and aluminium,a... Diamond/aluminium composites have attracted attention in the field of thermal management of electronic packaging for their excellent properties.In order to solve the interfacial problem between diamond and aluminium,a novel process combining pressure infiltration with vacuum-assisted technology was proposed to prepare diamond/aluminum composites.The effect of diamond particle size on the microstructure and properties of the diamond/Al-12Si composites was investigated.The results show that the diamond/Al-12Si composites exhibit high relative density and a uniform microstructure.Both thermal conductivity and coefficient of thermal expansion increase with increasing particle size,while the bending strength exhibits the opposite trend.When the average diamond particle size increases from 45μm to 425μm,the thermal conductivity of the composites increases from 455 W·m^(-1)·K^(-1)to 713 W·m^(-1)·K^(-1)and the coefficient of thermal expansion increases from 4.97×10^(-6)K^(-1)to 6.72×10^(-6)K^(-1),while the bending strength decreases from 353 MPa to 246 MPa.This research demonstrates that high-quality composites can be prepared by the vacuum-assisted pressure infiltration process and the thermal conductivity of the composites can be effectively improved by increasing the diamond particle size. 展开更多
关键词 diamond/aluminum composites thermal conductivity electronic packaging vacuum-assisted pressure infiltration
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Incorporation of Ionic Conductive Polymers into Sulfide Electrolyte-Based Solid-State Batteries to Enhance Electrochemical Stability and Cycle Life
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作者 Juhyoung Kim Woonghee Choi +1 位作者 Seong-Ju Hwang Dong Wook Kim 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第6期4-12,共9页
Sulfide-based inorganic solid electrolytes are promising materials for high-performance safe solid-state batteries.The high ion conductivity,mechanical characteristics,and good processability of sulfide-based inorgani... Sulfide-based inorganic solid electrolytes are promising materials for high-performance safe solid-state batteries.The high ion conductivity,mechanical characteristics,and good processability of sulfide-based inorganic solid electrolytes are desirable properties for realizing high-performance safe solid-state batteries by replacing conventional liquid electrolytes.However,the low chemical and electrochemical stability of sulfide-based inorganic solid electrolytes hinder the commercialization of sulfide-based safe solid-state batteries.Particularly,the instability of sulfide-based inorganic solid electrolytes is intensified in the cathode,comprising various materials.In this study,carbonate-based ionic conductive polymers are introduced to the cathode to protect cathode materials and suppress the reactivity of sulfide electrolytes.Several instruments,including electrochemical spectroscopy,X-ray photoelectron spectroscopy,and scanning electron microscopy,confirm the chemical and electrochemical stability of the polymer electrolytes in contact with sulfide-based inorganic solid electrolytes.Sulfide-based solid-state cells show stable electrochemical performance over 100 cycles when the ionic conductive polymers were applied to the cathode. 展开更多
关键词 composite cathode electrochemical stability ionic conductive polymer solid-state battery sulfide solid electrolyte
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Evaluation of Dielectric Properties of CCTO-BT/Epoxy Composites for Electronic Applications
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作者 Swagatika Mishra Punyapriya Mishra +3 位作者 Punyatoya Mishra Dinesh Kumar Mishra Krushna Prasad Shadangi Deepak Kumar Mohapatra 《Journal of Harbin Institute of Technology(New Series)》 CAS 2024年第1期69-77,共9页
In the current study,the calcium copper titanate(CCTO)/epoxy,barium titanate(BT)/epoxy and CCTO-BT/epoxy composite samples with variable volume fractions of CCTO and BT are fabricated using hand lay-up and compression... In the current study,the calcium copper titanate(CCTO)/epoxy,barium titanate(BT)/epoxy and CCTO-BT/epoxy composite samples with variable volume fractions of CCTO and BT are fabricated using hand lay-up and compression moulding process. The composite samples are characterized for the frequency dependence on dielectric properties,conductivity,impedance spectroscopy and electrical modulus.X-ray diffraction(XRD)representation of CCTO-BT/epoxy composite samples confirmed the presence of both CCTO and BT ceramic samples separately. The dielectric characteristics of hybrid CCTO-BT/epoxy composite samples with CCTO∶BT ratio of 40∶60, 60∶40,and 50∶50 was found relatively better than those of single ceramic filler reinforced epoxy composites. AC conductivity analysis shows improvement in the results of hybrid filler-filled CCTO-BT/epoxy composites in comparison with single filler-filled epoxy composite.50∶50 CCTO-BT/epoxy composite shows the best AC conductivity value of~ 2.2 ×10^(-5) ohm^(-1)·m^(-1) at a higher frequency of 1MHz. The impedance analysis confirms the higher insulating properties for hybrid 40∶60 and 60∶40 CCTO-BT/epoxy composites with respect to the single and other hybrid ceramic epoxy composites. The analysis suggests the hybrid CCTO-BT/epoxy composites to be adopted as a potential dielectric material for energy storage devices and other electronic applications. 展开更多
关键词 ceramic filler dielectric characterization hybrid composite AC conductivity impedance analysis
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Optimized CeO_(2) Nanowires with Rich Surface Oxygen Vacancies Enable Fast Li-Ion Conduction in Composite Polymer Electrolytes 被引量:2
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作者 Lu Gao Nan Wu +7 位作者 Nanping Deng Zhenchao Li Jianxin Li Yong Che Bowen Cheng Weimin Kang Ruiping Liu Yutao Li 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2023年第1期218-223,共6页
Low-cost and flexible solid polymer electrolytes are promising in all-solid-state Li-metal batteries with high energy density and safety.However,both the low room-temperature ionic conductivities and the small Li^(+)t... Low-cost and flexible solid polymer electrolytes are promising in all-solid-state Li-metal batteries with high energy density and safety.However,both the low room-temperature ionic conductivities and the small Li^(+)transference number of these electrolytes significantly increase the internal resistance and overpotential of the battery.Here,we introduce Gd-doped CeO_(2) nanowires with large surface area and rich surface oxygen vacancies to the polymer electrolyte to increase the interaction between Gd-doped CeO_(2) nanowires and polymer electrolytes,which promotes the Li-salt dissociation and increases the concentration of mobile Li ions in the composite polymer electrolytes.The optimized composite polymer electrolyte has a high Li-ion conductivity of 5×10^(-4)4 S cm^(-1) at 30℃ and a large Li+transference number of 0.47.Moreover,the composite polymer electrolytes have excellent compatibility with the metallic lithium anode and high-voltage LiNi_(0.8)Mn _(0.1)Co_(0.1)O_(2)(NMC)cathode,providing the stable cycling of all-solid-state batteries at high current densities. 展开更多
关键词 composite polymer electrolytes Gd-doped CeO_(2)nanowires Li-ion conduction oxygen vacancies surface interaction
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Physical and Thermo-Mechanical Properties of Composite Materials Based on Raw Earth and Crushed Palm Leaf Fibers (Borassus aethiopum)
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作者 Mouhamadou Nabi Kane Mapathe Ndiaye +1 位作者 Pape Moussa Touré Adama Dione 《Materials Sciences and Applications》 2024年第9期358-377,共20页
The objective of this study is to seek solutions to reduce the impact of buildings on climate change and to promote the use of local bio-sourced or geo-sourced materials for sustainable construction. Different samples... The objective of this study is to seek solutions to reduce the impact of buildings on climate change and to promote the use of local bio-sourced or geo-sourced materials for sustainable construction. Different samples of raw earth from 3 sites were taken in the commune of Mlomp. Geotechnical tests showed that the raw earth samples from sites 2 and 3 have more clay fraction while site 1 contains more sand. The fact of integrating fibers from crushed palm leaves (Borassus aethiopum) (2%, 4% and 6%) into the 3 raw earth samples reduced the mechanical resistance to compression and traction of the 3 raw earths. The experimental results of thermal tests on samples of earth mixtures with crushed Palma leaf fibers show a decrease in thermal conductivity as well as thermal effusivity as the percentages increase (2%, 4% and 6%) of fibers in raw earth for the 3 sites. This shows that this renewable composite material can help improve the thermal insulation of building envelopes. 展开更多
关键词 Raw Earth Palma Leaf Fibers Ecological composite Materials PHYSICAL Thermo-Mechanical Thermal conductivity Thermal Effusivity
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Multifunctional Composite Material with Efficient Microwave Absorption and Ultra-High Thermal Conductivity
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作者 王云 韩天成 +1 位作者 梁迪飞 邓龙江 《Chinese Physics Letters》 SCIE EI CAS CSCD 2023年第10期55-59,共5页
The increasing demands for electronic devices to achieve high miniaturization,functional integration,and wide bandwidth will exacerbate the heat generation and electromagnetic interference,which hinders the further de... The increasing demands for electronic devices to achieve high miniaturization,functional integration,and wide bandwidth will exacerbate the heat generation and electromagnetic interference,which hinders the further development of electronic devices.Therefore,both the issues of microwave absorption and heat dissipation of materials need to be addressed simultaneously.Herein,a multifunctional composite material is proposed by periodic arrangement of copper pillars in a matrix,based on the wave-absorbing material.As a result,the equivalent thermal conductivity of the composite structure is nearly 35 times higher than the wave-absorbing matrix,with the area filling proportion of the thermal conductivity material being 3.14%.Meanwhile,the reflectivity of the composite structure merely changes from-15.05 d B to-13.70 d B.It is proved that the designed composite structure possesses both high thermal conduction and strong microwave absorption.The measured results accord well with the simulation results,which demonstrates that the thermal conductivity of the composite structure can reach more than 10 W·m^(-1)·K^(-1)without significant deterioration of the absorption performance. 展开更多
关键词 composite MICROWAVE conductIVITY
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