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126 results on '"Huang, Liwu"'

22. Superfine SnO2–xParticles Embedded in a Porous Carbon Matrix as a Separator-Modifying Material for High-Performance Lithium Sulfur Batteries

Author

Qi, Xinmei, Huang, Liwu, and Chen, Yungui

Abstract

The commercialization of lithium sulfur batteries faces great challenges, such as shuttle effect and low conductivity. Herein, we explore embedding anoxic oxide SnO2–xin a porous carbon matrix as a separator-modifying material for lithium sulfur batteries. This material can limit the size of SnO2–xparticles and reduce their agglomeration through confining by the porous carbon (PC). As a result, more adsorption and catalytic sites can be obtained. Moreover, the oxygen vacancies in SnO2–xcan change the electronic environment to enhance the adsorption and catalysis of polysulfides, resulting in the depression of the shuttle effect of the battery. Therefore, the lithium sulfur battery with the SnO2–x/PC-modified separator has excellent cycling performance. At a current rate of 1 C, it can provide a high initial discharge capacity of 1049.4 mAh g–1and maintain a reversible specific capacity of 798.4 mAh g–1after 300 cycles.

Published
2023
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26. Advanced study of hydrogen storage by substitutional doping of Mn and Ti in Mg2Ni phase

Author

Elkedim Omar, Huang Liwu, and Bassir David

Subjects
first principles calculation, mn-doped mg2ni, ti-doped mg2ni, enthalpy of formation, Industrial engineering. Management engineering, T55.4-60.8, Industrial directories, T11.95-12.5
Abstract

The substitutional doping of Mn and Ti in Mg2Ni phase has been investigated by first principles density functional theory calculations. The calculation of enthalpy of formation shows that among the four different lattice sites of Mg(6f), Mg(6i), Ni(3b) and Ni(3d) in Mg2Ni unit cell, the most preferable site of substitution of Mn in Mg2Ni lattice has been confirmed to be Mg(6i) lattice site. The most preferable site of Ti substitution in Mg2Ni lattice is Mg(6i) position and the stability of Ti-doped Mg2Ni decreases with the increase of substitution quantity of Ti for Mg.

Published
2014
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28. Sr2+ and Mo6+ co-doped Li7La3Zr2O12 with superior ionic conductivity

Author

Zhou, Xiaoren, Huang, Liwu, EL KEDIM, Omar, Xie, Yuexin, Luo, Yiteng, Chen, Qinghao, Zhang, Yang, Chen, Yungui, Femto-st, MN2S, Sichuan University [Chengdu] (SCU), Franche-Comté Électronique Mécanique, Thermique et Optique - Sciences et Technologies (UMR 6174) (FEMTO-ST), Université de Technologie de Belfort-Montbeliard (UTBM)-Ecole Nationale Supérieure de Mécanique et des Microtechniques (ENSMM)-Université de Franche-Comté (UFC), and Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [SPI.ACOU] Engineering Sciences [physics]/Acoustics [physics.class-ph], [SPI.NANO] Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics, [SPI.MAT] Engineering Sciences [physics]/Materials, [SPI.MAT]Engineering Sciences [physics]/Materials
Abstract

International audience; Li7La3Zr2O12 (LLZO), a kind of solid-state electrolyte possessing the potential to realize an all-solid-state battery, attracts lots of attention. The Sr2+ and Mo6+ are co-doped into LLZO to obtain Li6.6+xLa3−xSrxZr1.8Mo0.2O12, in which x varies from 0 to 0.2. The strategy of doping Mo6+ into Zr4+-site can effectively ensure the formation of the cubic phase. On the basis of Zr4+-site doping method, doping appropriate Sr2+ can further improve the ionic conductivity and the relative density of the sample. A low temperature of 1100 °C and the cold pressing sintering method are applied. Through X-ray diffraction (XRD), Raman spectrum, inductively coupled plasma-optical emission spectroscopy (ICP-OES) and scanning electron microscope (SEM), we further discuss the mechanism of doping elements into lattice of LLZO. When x = 0.05, the sample Li6.65La2.95Sr0.05Zr1.8Mo0.2O12 exhibits the ionic conductivity of 6.43 × 10−4 S cm−1 (the highest among the works which used single Sr2+ or Mo6+ to dope LLZO) and the relative density of 95%.

Published
2021

30. Effect of Qizhitongluo capsule on lower limb rehabilitation after stroke: A randomized clinical trial

Author

Yu, Yanan, primary, Tang, Lu, additional, Cui, Fangyuan, additional, Jiao, Fuying, additional, Zhang, Dong, additional, Ma, Jin, additional, Ding, Wentao, additional, Yu, Yingmei, additional, Zhang, Bo, additional, Meng, Zhihong, additional, Dai, Xiaoyu, additional, Liu, Dequan, additional, Chang, Jingjing, additional, Qu, Yun, additional, Li, Yi, additional, Wang, Hongzhi, additional, Wang, Xinzhi, additional, Liu, Xiangzhe, additional, Zhou, Hongxia, additional, Zhao, Jianjun, additional, Wang, Yue, additional, Zhang, Yidan, additional, Ma, Qiang, additional, Liu, Kun, additional, Liang, Jin, additional, Lu, Yun, additional, Xiaomin, Yu, additional, Song, Yingmin, additional, Guo, Erya, additional, Li, Xutao, additional, Yang, Qingtang, additional, Huang, Liwu, additional, Wu, Peng, additional, Wang, Jinbao, additional, Liu, Jun, additional, Li, Bing, additional, Chen, Bingwei, additional, Chen, Qiguang, additional, Yue, Qingqing, additional, Xie, Yingzhen, additional, Wang, Yongyan, additional, and Wang, Zhong, additional

Published
2021
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33. The electrochemical performance of AB5H6 as anode material for lithium-ion batteries.

Author

Leng, Jie, Huang, Liwu, Qi, Xinmei, Zhou, Xiaoren, and Chen, Yungui

Abstract

AB5-type hydrogen-absorbing alloys, owning the characteristic of good kinetic characteristics, moderate pressure and easy activation, have arisen much attention to researchers. Herein, we study the AB5H6 (A = mischmetal: La, Ce, Pr, and B = Ni, Co, Mn and Al with the molar ratio of 3.7:0.7:0.3:0.3) as anode material for lithium-ion batteries, and the AB5H6 with different carbon conductive agents have been designed for studying their electrochemical performance. The prepared AB5H6-UGS (ultrathin graphite sheets) electrode shows the discharge capacity of 394.2 mAhg−1 at a current density of 10 mAg−1. In order to explore the charge/discharge reaction mechanism, ex situ XRD (X-ray diffraction) is applied to detect the phase evolution of the AB5H6-UGS anode during the charge/discharge. It is found that the reaction of the AB5H6 with lithium includes two steps, namely, the conversion reaction of AB5H6 with Li+ at about 0.5 V and the followed alloying reaction of AB5 with lithium. SEM (scanning electron microscope) is used to observe the change of morphology. [ABSTRACT FROM AUTHOR]

Published
2022
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38. Highly Graphitized Porous Carbon‐FeNi3 Fabricated from Oleic Acid for Advanced Lithium–Sulfur Batteries.

Author

Chen, Lin, Huang, Liwu, Chen, Guojie, Zhang, Xinlin, and Chen, Yungui

Subjects
*LITHIUM sulfur batteries, *OLEIC acid, *GRAPHITIZATION, *NANOPARTICLES, *ELECTRIC conductivity, *CHEMICAL kinetics, *CARBON foams, *LITHIUM cells
Abstract

Improving the electrical conductivity of sulfur, suppressing shuttle/dissolution of polysulfide, and enhancing reaction kinetics in Li–S batteries are essential for practical applications. Here, for the first time, we have used inexpensive oleic acid as a single carbon source, and have added commercial SiO2 as a template to form a porous structure, whereas introducing Fe(NO3)3 and Ni(NO3)2 as catalysts to increase the degree of graphitization. Moreover, the dual metal salts Fe(NO3)3 and Ni(NO3)2 can also form FeNi3 alloy, and our results show that FeNi3 nanoparticles accelerate the kinetic conversion reactions of polysulfide. By virtue of the well‐developed porous structure and high degree of graphitization, the highly graphitized porous carbon‐FeNi3 (GPC‐FeNi3) has high conductivity to ensure fast charge transfer, and the hierarchically porous structure facilitates ion diffusion and traps polysulfide. Thus, a GPC‐FeNi3/S cathode displays excellent electrochemical performance. At current rates of 0.2 and 1 C, a cathode of the GPC‐FeNi3/S composite with a sulfur content of 70 % delivers high initial discharge capacities of 1108 and 880 mA h g−1, respectively, and retains reversible specific capacities of 850 mA h g−1 after 200 cycles at 0.2 C and 625 mA h g−1 after 400 cycles at 1 C. [ABSTRACT FROM AUTHOR]

Published
2020
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46. Hollow Boron-Doped Si/SiOxNanospheres Embedded in the Vanadium Nitride/Nanopore-Assisted Carbon Conductive Network for Superior Lithium Storage

Author

Zhang, Xinlin, Huang, Liwu, Shen, Qianqian, Zhou, Xiaoren, and Chen, Yungui

Abstract

SiOx-based anode materials with high capacity and outstanding cycling performance have gained numerous attentions. Nevertheless, the poor electrical conductivity and non-negligible volume change hinder their further application in Li-ion batteries. Herein, we propose a new strategy to construct a hollow nanosphere with boron-doped Si/SiOxdecorated with vanadium nitride (VN) nanoparticles and embedded in a nitrogen-doped, porous, and partial graphitization carbon layer (B-Si/SiOx@VN/PC). Benefiting from such structural and compositional features, the B-Si/SiOx@VN/PC electrode exhibits a stable cycling capacity of 1237.1 mA h g–1at a current density of 0.5 A g–1with an appealing capacity retention of 87.0% after 300 cycles. Additionally, it delivers high-rate capabilities of 1139.4, 940.7, and 653.4 mA h g–1at current densities of 2, 5, and 10 A g–1, respectively, and ranks among the best SiOx-based anode materials. The outstanding electrochemical performance can be ascribed to the following reasons: (1) its hollow structure makes the Li+transportation length decreased. (2) The existing nanopores facilitate the Li+insertion/desertion and accommodate the volume variation. (3) The nitrogen-doped partial graphitization carbon enhances the electrical conductivity and promotes the formation of stable solid electrolyte interface layers during the repetitive Li+intercalation/extraction process.

Published
2019
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47. Double-perovskite Ca2AlNbO6: Mn4+ red phosphor for white light emitting diodes: synthesis, structure and luminescence properties.

Author

Luo, Kuankuan, Zhang, Yan, Xu, Jiayue, Yuan, Junping, Huang, Liwu, and Xiang, Di

Subjects
LIGHT emitting diodes, MANGANESE, PHOSPHORS, PHOTOLUMINESCENCE, METAL quenching
Abstract

The red-emitting phosphors Ca2AlNbO6: xmol%Mn4+ (CAN: xmol%Mn4+) (0.1 ≤ x ≤ 0.9) were successfully synthesized via a conventional high temperature solid-state method at air atmosphere. A band was located at 320 nm in diffuse reflection spectra (DRS) because of the spin-allowed 4A2g → 4T1g transition of Mn4+. Moreover, there were two broad bands located at photoluminescence excitation (PLE) spectra due to the spin-allowed transitions of Mn4+ upon the excitation of 712 nm. And the phosphors exhibited the far-red emission bands centered at ~ 712 nm on account of the spin-forbidden 2Eg → 4A2g transition of Mn4+ under the excitation of 355 nm. And the optimum one was CAN: 0.3 mol%Mn4+ which yields the brightest red light due to the concentration quenching effect. Furthermore, it could be confirmed that the existence of nonradiative among Mn4+ ions because the lifetime of the phosphors was decreased as the concentration of Mn4+ in CAN increased from 0.1% to 0.9 mol%. The average lifetime of the phosphors was in the range of miscroscend. In addition, the CIE chromaticity coordinates of CAN: 0.3 mol%Mn4+ were (0.7319, y = 0.2618). Finally, a blue LED chip combined with YAG: Ce3+ yellow and CAN: 0.3 mol% Mn4+ red phosphors to fabricate a warm white light emitting-diode (WLED). And the CIE chromaticity coordinates, color rendering index (CRI) and the corrected color temperature (CCT) of the device were (0.3799, 0.3432), 74.2 and 3727 K, respectively. [ABSTRACT FROM AUTHOR]

Published
2019
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