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Deciphering the potassium storage phase conversion mechanism of phosphorus by combined solid-state NMR spectroscopy and density functional theory calculations

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Journal of Energy Chemistry 2023年第4期79卷 45-53页

作者： huixin chen Lingyi Meng Hongjun Yue chengxin Peng Qiaobao Zhang Guiming Zhong Ding chen State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082HunanChina CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Provincial Key Laboratory of NanomaterialsFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002FujianChina Laboratory of Advanced Spectro-electrochemistry and Li-ion Batteries Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamen 361021FujianChina Department of Materials Science and Engineering College of MaterialsXiamen UniversityXiamen 361005FujianChina School of Materials Science and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China

Phosphorus is the potential anode material for emerging potassium-ion batteries(PIBs)owing to the highest specific capacity and relatively low operation ***,the reversible delivered capacities of phosphorus-based anodes,in reality,are far from the theoretical capacity corresponding to the formation of K3P ***,their underlying potassium storage mechanisms remain poorly *** address this issue,for the first time,we perform high-resolution solid-state31P NMR combined with XRD measurements,and density functional theory calculations to yield a systemic quantitative understanding of(de)potassiation reaction mechanism of phosphorus *** explicitly reveal a previously unknown asymmetrical nanocrystalline-to-amorphous transition process via rP←→(K_(3)P_(11),K_(3)P_(7),beta-K_(4)P_(6))←→(alpha-K4P6)←→(K_(1-x)P,KP,K_(4-x)P3,K_(1+x)P)←→(amorphous K4P3,amorphous K3P)that are proceed along with the electrochemical potassiation/depotassiation ***,the corresponding KP alloys intermediates,such as the amorphous phases of K_(4)P_(3),K_(3)P,and the nonstoichiometric phases of“K_(1-x)P”,“K_(1+x)P”,“K_(4-x)P_(3)”are experimentally detected,which indicating various complicated K-P alloy species are coexisted and evolved with the sluggish electrochemical reaction kinetics,resulting in lower capacity of phosphorus-based *** findings offer some insights into the specific multi-phase evolution mechanism of alloying anodes that may be generally involved in conversion-type electrode materials for PIBs.

关键词： Red phosphorus Phase conversion Solid-state NMR Potassium ion batteries

Water content distribution in the surface layer of Maoping slope

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Science China(Technological Sciences) 2005年第Z1期48卷 157-170页

作者： LIU Yuewu chen huixin LIU Qingquan GONG Xin ZHANG Dawei LI Lianxiang Division of Engineering Science Institute of MechanicsChinese Academy of SciencesBeijing 100080China

The water content distribution in the surface layer of Maoping slope has been studied by testing the water content at 31 control *** water content profiles at these sites have also been *** water content distributions at different segments have been obtained by using the Kriging method of *** comparing the water content distributions with the landform of the slope,it was shown that the water content is closely dependent on the landform of the *** water content distribution in the surface layer provided a fundamental basis for landslide predication and treatment.

关键词： landslide water content in situ test Kriging method geostatistics.

Experimental study on pore pressure in rock-soil slope during reservoir water level fluctuation

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Science China(Technological Sciences) 2005年第Z1期48卷 196-208页

作者： LIU Yuewu chen huixin LIU Qingquan GONG Xin ZHANG Dawei LI Lianxiang Division of Engineering Science Institute of Mechanics Chinese Academy of Sciences Beijing 100080 Division of Engineering Science Institute of Mechanics Chinese Academy of Sciences Beijing 100080 Division of Engineering Science Institute of Mechanics Chinese Academy of Sciences Beijing 100080 Division of Engineering Science Institute of Mechanics Chinese Academy of Sciences Beijing 100080 Division of Engineering Science Institute of Mechanics Chinese Academy of Sciences Beijing 100080 Division of Engineering Science Institute of Mechanics Chinese Academy of Sciences Beijing 100080

A test system was developed for measuring the pore pressure in porous media, and a new model was devised for the pore pressure testing in both saturated and unsaturated rock-soil. Laboratory experiments were carried out to determine the pore pressure during water level fluctuation. The variations of transient pore pressure vs. time at different locations of the simulated rock-soil system were acquired and processed, and meanwhile the deformation and failure of the model are observed. The experiment results show that whether the porous media are saturated or not, the transient pore pressure is mainly dependent on the water level fluctuation, and coupled with the variation of the stress field.

关键词： landslide, pore pressure, reservoir water level, rock-soil.

Reversible potassium storage in ultrafine CF_(x): A superior cathode material for potassium batteries and its mechanism

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Journal of Energy Chemistry 2021年第2期30卷 347-353,I0012页

作者： Hongjun Yue huixin chen chen Zhao Zhiming Zheng Ke Zhou Qjaobao Zhang Guiming Zhong Can-Zhong Lu Yong Yang CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Provincial Key Laboratory of NanomaterialsFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002FujianChina Xiamen Institute of Rare Earth Materials Haixi Institutes.Chinese Academy of SciencesXiamen 361021Fujian.China College of Chemistry Fuzhou University.Fuzhou 350108FujianChina Department of Materials Science and Engineering College of MaterialsXiamen UniversityXiamen 361005FujianChina State Key Lab of Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materials and Department of ChemistryXiamen UniversityXiamen 361005FujianChina

Current studies of cathodes for potassium batteries(PBs) mainly focus on the intercalation-type *** conversion-type materials that possess much higher theoretical capacities are rarely discussed in previous *** this work,carbon fluoride(CF_x) is reported as a high capacity conversion-type cathode for PBs for the first *** material delivers a remarkable discharge capacity of>250 mAh g^(-1) with mid-voltage of 2.6 V at 20 mA g^(-1).Moreover,a highly reversible capacity of around 95 mAh g^(-1) is achieved at 125 mA g^(-1) and maintained for 900 cycles,demonstrating its excellent cycling *** mechanism of this highly reversible conversion reaction is further investigated by nuclear magnetic resonance spectra,X-ray diffraction,and transmission electron microscopy *** to the analyses,the C-F bond in the cycled material is different from that in the pristine state,which presents relatively higher *** finding offers important insights for further improving the performance of the CF_*** work not only demonstrates the CF_x as a high performance cathode for PBs,but also paves a new avenue of exploring conversion-type cathodes for high energy density PBs.

关键词： Potassium batteries Carbon fluoride NMR spectroscopy Conversion reaction Cathode

Tea-derived carbon materials as anode for high-performance sodium ion batteries

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Chinese Chemical Letters 2023年第4期34卷 519-525页

作者： Huayan Wang huixin chen Chi chen Miao Li Yiming Xie Xingcai Zhang Xianwen Wu Qiaobao Zhang Canzhong Lu Engineering Research Center of Environment-Friendly Function Materials Ministry of EducationInstitute of Materials Physical ChemistryHuaqiao UniversityXiamen 361021China CAS key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Provincial Key Laboratory of NanomaterialsFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Department of Materials Science and Engineering College of MaterialsXiamen UniversityXiamen 361005China School of Engineering and Applied Sciences Harvard UniversityCambridgeMA 02138United States School of Engineering Massachusetts Institute of TechnologyCambridgeMA 02139United States Xiamen Key Laboratory of Rare Ear School of Chemistry and Chemical Engineering Jishou UniversityJishou 416000China

Sodium-ion batteries(SIB) have attracted widespread attention in large-scale energy storage fields owing to the abundant reserve in the earth and similar properties of sodium to lithium. Biomass-based carbon materials with low-cost, controllable structure, simple processing technology, and environmental friendliness tick almost all the right boxes as one of the promising anode materials for SIB. Herein, we present a simple novel strategy involving tea tomenta biomass-derived carbon anode with enhanced interlayer carbon distance(0.44 nm) and high performance, which is constructed by N,P co-doped hard carbon(Tea-1100-NP) derived from tea tomenta. The prepared Tea-1100-NP composite could deliver a high reversible capacity(326.1 m Ah/g at 28 m A/g), high initial coulombic efficiency(ICE = 90% at 28 m A/g),stable cycle life(262.4 m Ah/g at 280 m A/g for 100 cycles), and superior rate performance(224.5 m Ah/g at 1400 m A/g). Experimental results show that the excellent electrochemical performance of Tea-1100-NP due to the high number of active N,P-containing groups, and disordered amorphous structures provide ample active sites and increase the conductivity, meanwhile, large amounts of microporous shorten the Na+diffusion distance as well as quicken ion transport. This work provides a new type of N,P co-doped high-performance tomenta-derived carbon, which may also greatly promote the commercial application of SIB.

关键词： Tea tomenta Co-doped Hard carbon Initial coulombic efficiency Sodium-ion batteries

Numerical study on rainfall infiltration in rock-soil slop

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Science China(Technological Sciences) 2005年第Z1期48卷 33-46页

作者： LIU Yuewu LIU Qingquan chen huixin GONG Xin ZHANG Dawei YAO Deliang LI Lianxiang Division of Engineering Science Institute of MechanicsChinese Academy of SciencesBeijing 100080China

A mathematical model for the rain infiltration in the rock-soil slop has been established and solved by using the finite element *** unsteady water infiltrating process has been simulated to get water content both in the homogeneous and heterogeneous *** simulated results show that the rock blocks in the rock-soil slop can cause the wetting front moving *** the rain intensity is increased,the saturated region will be formed quickly while other conditions are the *** the rain intensity keeps a constant,it is possible to accelerate the generation of the saturated region by properly increasing the vertical filtration rate of the rock-soil ***,if the vertical filtration rate is so far greater than the rain intensity,it will be difficult to form the saturated region in the rock-soil *** numerical method was verified by comparing the calculation results with the field test data.

关键词： rock-soil block rainfall water content infiltration Finite Element Method(FEM).

Theory and application of the transient injection well test

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Science China(Technological Sciences) 2005年第Z1期48卷 121-135页

作者： LIU Yuewu chen huixin LIU Qingquan GONG Xin ZHANG Dawei YAO Deliang LI Lianxiang Division of Engineering Science Institute of MechanicsChinese Academy of SciencesBeijing 100080

Based on the theory of the pumping well test,the transient injection well test was suggested in this *** design method and the scope of application are discussed in *** mathematical models are developed for the short-time and long-time transient injection test respectively.A double logarithm type curve matching method was introduced for analyzing the field transient injection test data.A set of methods for the transient injection test design,experiment performance and data analysis were *** field tests were analyzed,and the results show that the test model and method are suitable for the transient injection test and can be used to deal with the real engineering problems.

关键词： injection test transient injection well test seepage flow permeability coefficient analysis method.

N-doped porous carbon nanofibers sheathed pumpkin-like Si/C composites as free-standing anodes for lithium-ion batteries

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Journal of Energy Chemistry 2021年第3期30卷 727-735页

作者： Yanfei Zeng Yudai Huang Niantao Liu Xingchao Wang Yue Zhang Yong Guo Hong-Hui Wu huixin chen Xincun Tang Qiaobao Zhang Key Laboratory of Energy Materials Chemistry Ministry of EducationKey Laboratory of Advanced Functional MaterialsAutonomous RegionInstitute of Applied ChemistryCollege of ChemistryXinjiang UniversityUrumqi 830046XinjiangChina Department of Materials Science and Engineering College of MaterialsXiamen UniversityXiamen 361005FujianChina Beijing Advanced Innovation Center for Materials Genome Engineering School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China School of Chemistry and Chemical Engineering Central South UniversityChangsha 410083HunanChina Xiamen Institute of Rare Earth Materials Haixi InstitutesChinese Academy of SciencesXiamen 361024FujianChina

Dramatic capacity fading and poor rate performance are two main obstacles that severely hamper the widespread application of the Si anode owing to its large volume variation during cycling and low intrinsic electrical *** mitigate these issues,free-standing N-doped porous carbon nanofibers sheathed pumpkin-like Si/C composites(Si/C-ZIF-8/CNFs)are designed and synthesized by electrospinning and carbonization methods,which present greatly enhanced electrochemical properties for lithium-ion battery *** particular structure alleviates the volume variation,promotes the formation of stable solid electrolyte interphase(SEI)film,and improves the electrical *** a result,the as-obtained free-standing Si/C-ZIF-8/CNFs electrode delivers a high reversible capacity of 945.5 mAh g^(-1) at 0.2 A g^(-1) with a capacity retention of 64% for 150 cycles,and exhibits a reversible capacity of 538.6 mA h g^(-1) at 0.5 A g^(-1) over 500 ***,the full cell composed of a freestanding Si/C-ZIF-8/CNFs anode and commercial LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)(NCM)cathode shows a capacity of 63.4 mA h g^(-1) after 100 cycles at 0.2 C,which corresponds to a capacity retention of 60%.This rational design could provide a new path for the development of high-performance Si-based anodes.

关键词： Pumpkin-like silicon/carbon composites N-doped porous carbon nanofibers Free-standing anode Lithium-ion batteries

Oxygen self-doping pyrolyzed polyacrylic acid as sulfur host with physical/chemical adsorption dual function for lithium-sulfur batteries

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Chinese Chemical Letters 2024年第7期35卷 473-479页

作者： Yan Wang huixin chen Fuda Yu Shanyue Wei Jinhui Song Qianfeng He Yiming Xie Miaoliang Huang Canzhong Lu Engineering Research Center of Environment-Friendly Functional Materials Ministry of EducationInstitute of Materials Physical ChemistryHuaqiao UniversityXiamen 361021China CAS Key Laboratory of Design and Assembly of Functional Nanostructures and Fujian Provincial Key Laboratory of NanomaterialsFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamen 361021China

Lithium-sulfur(Li-S)batteries with high theoretical capacity and energy density need to solve problems such as the high decomposition energy barrier of Li_(2)S and large volume change of sulfur in the charging process caused by the shuttle effect before practical ***,a green synthesis method is used to prepare polyacrylic acid(PAA)superabsorbent material,and then the pyrolyzed PAA(P/PAA)material is obtained as the positive electrode of Li-S *** functional calculation reveals that the oxygen self-doping pyrolyzed polyacrylic acid(P/PAA)delivered stronger binding energy toward Li2S species in carbonyl C=O than that of graphite powder(GP)which are-1.58 eV and-1.02 eV,*** with the distribution of relaxation time analysis and the in-situ electrochemical impedance approach,it is further demonstrated that the designed P/PAA as sulfur host plays a physical/chemical adsorption dual function in maintaining the stability and rate performance of *** an initial discharge capacity of 1258 mAh/g at 0.1 C and a minimal capacity decline of 0.05%per cycle even after 800 cycles at 0.5 C,the produced cathode demonstrated outstanding electrochemical *** average Coulombic efficiency is nearly 100%.The P/PAA electrodes may typically retain 96%of their capacity while declining on average only 0.033%per cycle after 130 cycles at 3 *** effort provides a new method for the future development of heteroatomic self-doping superabsorbent with promising adsorption properties for polysulfides as cathode materials of Li-S batteries.

关键词： Polyacrylic acid Oxygen self-doping Green synthetic Pore mesh polymer cathodes Lithium-sulfur batteries