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Ultrathin 3 V Spinel Clothed layered Lithium-Rich Oxides as Heterostructured Cathode for High-Energy and High-Power Li-ion Batteries

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Chinese Journal of Chemistry 2021年第2期39卷 345-352页

作者： Liqin Dai Ning Li Lai Chen Yuefeng Su Cheng-Meng Chen Fangyuan Su Liying Bao Shi Chen Feng Wu Beijing Key Laboratory of Environmental Science and Engineering School of Material Science and EngineeringBeijing Institute of TechnologyBeijing100081 China Key Laboratory of Carbon Materials Institute of Coal ChemistryChinese Academy of SciencesTaiyuanShanxi030001 China Beijing Institute of Technology Chongqing Innovation Center Chongqing401120 China

In an attempt to overcome the drawbacks of high-capacity layered lithium-rich cathodes xLi2MnO3·(1–x)LiMO2(0layered heterostructured materials,x’Li4Mn5O12·(1–x’)Li[Li0.2Mn... 详细信息

In an attempt to overcome the drawbacks of high-capacity layered lithium-rich cathodes xLi2MnO3·(1–x)LiMO2(0layered heterostructured materials,x’Li4Mn5O12·(1–x’)Li[Li0.2Mn0.55Ni0.15Co0.1]O2(x’=0.01,0.03,0.05)have been proposed and synthesized as high-performance cathode materials for high-energy and high-power Li-ion batteries.Based on the characterizations of X-ray diffraction(XRD),transmission electron microscopy(TEM),Raman scattering spectroscopy,it is indicated that ultrathin 3 V spinel Li4Mn5O12 has been successfully clothed on the layered lithium-rich cathode.Electrochemical tests demonstrate the sample 0.01Li4Mn5O12·0.99 Li[Li0.2Mn0.55Ni0.15Co0.1]O2 with an ultrathin clothing layer of spinel phase,exhibits the highest reversible capacity of 289.4 mAh g^(-1) and maintains 259.8 mAh g^(-1) after 80 cycles at 0.1 C rate.Meanwhile,it delivers outstanding rate discharge capacities of 229.4 mAh g^(-1) at 1 C,216.8 mAh g^(-1) at 2 C and 184.4 mAh g^(-1) at 5 C as well as alleviated voltage fade.It is believed the ultrathin clothing spinel layer plays a vital role in the modification of the materials kinetics,and structural and electrochemical stability of the heterostructured cathode.

关键词： Li-ion batteries Heterostructure Layered compounds Spinel phases Electrochemistry

Electronic structure and mechanical properties of layered compound YB_2C_2:A promising precursor for making two dimensional(2D) B_2C_2 nets

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Journal of Materials Science & Technology 2017年第9期33卷 1044-1054页

作者： Yanchun Zhou Huimin Xiang Xiaohui Wang Wei Sun Fu-Zhi Dai Zhihai Feng Science and Technology of Advanced Functional Composite Laboratory Aerospace Research Institute of Materials & Processing Technology Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of Sciences

Layered compounds play pivotal roles as precursors for producing 2D materials through mechanical exfoliation(micro-mechanical cleavage) or chemical approaches. Therefore, searching for Layered compounds with sharp anisotropic chemical bonding and properties becomes emergent. In this work, the stability, electronic structure, elastic properties, and lattice dynamics of YBCwere investigated. Strong anisotropy in elastic properties is revealed, i.e., high Young’s modulus in a-b plane but low Young’s modulus in c direction. The maximum to minimum Young’s modulus ratio is 2.41 and 2.45 for YBCwith P42/mmc and P4/mbm symmetry, respectively. The most likely systems for shear sliding or microdelaminating are(001)[100] and(001)[010]. The anisotropic elastic properties are underpinned by the anisotropic chemical bonding, i.e., strong bonding within the BCnets and weak bonding between Y atom layers and BCnets. YBCis electrically conductive and the contributions to the electrical conductivity are from delocalized Y 4deas well as Bpandpzelectrons. The layered crystal structure, sharp anisotropic mechanical properties, and metallic conductivity endorse YBCpromising as a precursor for new 2D BCnets.

关键词： YB2C2 Layered compounds Electronic structure Mechanical properties 2D graphite like materials

Thixotropy of Aqueous Suspensions Containing Mg-AI Hydrotalcite-like Compound and Low-substituted Cationic Starch： Comparison between Oscillatory Shear and Thixotropic Loop Measurements

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Chinese Journal of Chemistry 2011年第6期29卷 1101-1106页

作者： Li, Yan Bi, Haoyu Shen, Shuanglong Department of Chemistry Changzhi College Changzhi Shanxi 046011 China Department of Biomedicine Engineering Changzhi Medical College Changzhi Shanxi 046000 China

The rheological properties of aqueous suspensions consisting of positively charged aluminum magnesium hydrotalcite-like compound （HTlc） and low-substituted cationic starch （LCS） were investigated. Special emphasis was placed on the thixotropic phenomenon. Thixotropic behavior was investigated by two thixotropic methods： thixotropic loop and oscillatory shear measurements. LCS molecules could be adsorbed onto HTlc particles due to the hydrogen bonding between ether groups or hydroxyl groups of LCS and hydroxyl groups of HTlc. The elastic dynamic response of the HTlc/LCS suspension increased with increasing mass ratio （R） of HTlc and a three-dimensional network structure could be formed in the suspension with higher R value. The thixotropic type of the HTlc/LCS suspension transformed from negative to positive and then to complex thixotropy when R changed from 0 to 0.5. By comparing between the thixotropic results obtained by thixotropic loop and oscillatory shear measurements, it was validated that the thixotropic loop for the suspension showing complex thixotropy had a crossover point.

关键词： colloids thixotropy Layered compounds hydrotalcite-like compounds low-substituted cationic starch

Studies on Mechanochemical Method to Synthesize LDH Nanoparticles

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Chinese Journal of Chemistry 2012年第2期30卷 277-282页

作者： Jia,Chunxiao Zhang,Xiaoqing Li,Shuping Department of Chemistry Dezhou UniversityDezhouShandong253023China Jiangsu Key Laboratory of Biofunctional Material College of Chemistry and Material ScienceNanjing Normal UniversityNanjingJiangsu 210097China

Magnesium-ferrum layered double hydroxide （Mg-Fe-LDH） and zinic-aluminum layered double hydroxide （Zn-A1-LDH） compounds were prepared through a mechanochemical method. The influence of molar ratio of M2＋ to M3＋（R value） on the property ofLDH nanoparticles has been studied and the results showed that R=3 ： 1 is the optimum value for the both samples. Besides pure water, the mixture of water and ethanol with the volume ratio of 3 ; 1 is also used to wash the precipitates and used as suspending agent during the peptization process and our results showed that the addition of ethanol can improve the monodispersity of LDH nanoparticles greatly.

关键词： mechanochemical method solvent-free reaction Layered compounds intercalations

Effect of Substitution of Cobalt for Iron in Sr4Fe6O13-δon the Catalytic Activity for Methane Combustion

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Chinese Journal of Chemistry 2011年第3期29卷 451-454页

作者： Feng, Shaojie Wang, Zhenghong Yang, Pinghua School of Materials Science and Chemical Engineering Anhui University of Architecture Hefei Anhui 230022 China Department of Materials Science and Engineering University of Science and Technology of China Hefei Anhui 230026 China

A series of mixed oxides Sr4Fe6-xCoxO13-δ （x=0, 1, 2, 3, or 4） were prepared by sol-gel method and used for catalytic combustion of methane. The structural properties of oxides were characterized by XRD, TGA, and XPS. The layered intergrowth perovskite-like oxide Sr4FesCoO13 8 exhibits the highest catalytic activity for methane combustion under the experimental conditions. The enhanced catalytic activity of Sr4FesCoO13-δfor methane combustion could be attributed to the increased amount of oxygen vacancy caused by the partial substitution of cobalt for iron in the Sr4Fe6O13, which was confirmed by TGA and XPS.

关键词： heterogeneous catalysis Layered compounds Sr4Fe6-xCoxO13-δ methane

A universal method for rapid and large‐scale growth of layered crystals

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SmartMat 2020年第1期1卷 77-84页

作者： Apoorva Chaturvedi Bo Chen Keke Zhang Qiyuan He Gwang‐Hyeon Nam Lu You Zhuangchai Lai Chaoliang Tan Thu Ha Tran Guigao Liu Jiadong Zhou Zheng Liu Junling Wang Edwin H.T.Teo Hua Zhang Center for Programmable Materials School of Materials Science and EngineeringNanyang Technological UniversitySingaporeSingapore Department of Chemistry City University of Hong KongHong KongChina Department of Materials Science and Engineering City University of Hong KongHong KongChina Jiangsu Key Laboratory of Thin Films School of Physical Science and TechnologySoochow UniversitySuzhouChina Department of Electrical Engineering City University of Hong KongHong KongChina Department of Physics Southern University of Science and TechnologyShenzhenGuangdongChina School of Electric and Electronic Engineering Nanyang Technological UniversitySingaporeSingapore Hong Kong Branch of National Precious Metals Material Engineering Research Center(NPMM) City University of Hong KongHong KongChina

layered van der Waals(vdW)materials,consisting of atomically thin layers,are of paramount importance in physics,chemistry,and materials science owing to their unique properties and various promising applications.However,their fast and large‐scale growth via a general approach is still a big challenge,severely limiting their practical implementations.Here,we report a universal method for rapid(~60 min)and large‐scale(gram scale)growth of phase‐pure,high‐crystalline layered vdW materials from their elementary powders via microwave plasma heating in sealed ampoules.This method can be used for growth of 30 compounds with different components(binary,ternary,and quaternary)and properties.The ferroelectric and transport properties of mechanically exfoliated flakes validate the high crystal quality of the grown materials.Our study provides a general strategy for the fast and large‐scale growth of layered vdW materials with appealing physiochemical properties,which could be used for various promising applications.

关键词： 2D materials ferroelectric field‐effect transistors Layered compounds universal method