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One-step synthesis of novel core-shell bimetallic hexacyanoferrate for high performance sodium-storage cathode

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Journal of materials Science & Technology 2022年第19期114卷 180-190页

作者： Daxian Zuo Cuiping Wang Jiajia Han Qinghao Han Yanan Hu Junwei Wu huajun Qiu Qian Zhang Xingjun Liu College of materials and Fujian Key Laboratory of materials Genome and Xiamen Key Laboratory of High Performance Metals and materials Xiamen UniversityXiamen 361005China Institute of materials Genome and Big Data Harbin Institute of TechnologyShenzhen 518055China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyShenzhen 518055China

Recently, the design of core-shell hierarchical architecture plays an important role in improving the electrochemical performance of Prussian blue analogue cathodes(PBAs). Unfortunately, the inconvenient stepwise preparation and the strict lattice-matching requirement have restricted the development of coreshell PBAs. Herein, we demonstrate a one-step synthesis strategy to synthesize core-shell manganese hexacyanoferrate(MnFeHCF@MnFeHCF) for the first time. And the formation mechanism of the core-shell hierarchical architecture is investigated by first-principles calculations. It is found that the as-obtained Mn FeHCF@MnFeHCF act out the superior intrinsic natures, which not only can obtain a larger specific surface area and lower Fe(CN)_(6) vacancies but also can activate more Na-storage sites. Compared with the manganese hexacyanoferrate(MnHCF), the iron hexacyanoferrate(FeHCF), and even the traditional coreshell nickel hexacyanoferrate(FeHCF@NiHCF) prepared by a stepwise method, the Mn Fe HCF@MnFeHCF demonstrates a superior rate performance, which achieves a high capacity of 131 mah g^(−1) at 50 ma g^(−1) and delivers a considerable discharge capacity of about 100 mah g^(−1) even at 1600 ma g^(−1). Meantime, the capacity retention can reach up to nearly 80% after 500 cycles. The improved performances could be mainly originated from two aspects: on the one hand, Mn substitution is helpful to enhance the material conductivity;on the other hand, the core-shell structure with matched lattice parameters is more favorable to enhance the diffusion coefficient of sodium ions. Beside, the structural transformation of MnFeHCF@MnFeHCF upon the extraction/insertion of sodium ions is instrumental in releasing the interior stress and effectively maintaining the integrity of the crystal structure.

关键词： Cathode Prussian blue analogue Core-shell structure First-principles calculations Electrochemical performance

Revealing the potential of apparent critical current density of Li/garnet interface with capacity perturbation strategy

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Journal of Energy Chemistry 2023年第4期79卷 56-63页

作者： Zhihao Guo Xinhai Li Zhixing Wang huajun Guo Wenjie Peng Guangchao Li Guochun Yan Qihou Li Jiexi Wang School of Metallurgy and Environment Central South UniversityChangsha 410083HunanChina Engineering Research Center of the Ministry of Education for Advanced Battery materials Central South UniversityChangsha 410083HunanChina Key Laboratory of Value-added Metallurgy of Hunan Province Central South UniversityChangsha 410083HunanChina

Apparent critical current density(j_(Ac)^(a))of garnet all-solid-state lithium metal symmetric cells(ASSLSCs)is a fundamental parameter for designing all-solid-state lithium metal ***,how much the possible maximum apparent current density that a given ASSLSC system can endure and how to reveal this potential still require ***,a capacity perturbation strategy aiming to better measure the possible maximum j_(Ac)^(a)is proposed for the first *** garnet-based plane-surface structure ASSLSCs as an exemplification,the j_(Ac)^(a)is quite small when the capacity is dramatically *** a perturbed capacity of 0.001 ma h cm^(-2),the j_(Ac)^(a)is determined to be as high as 2.35 ma cm^(-2)at room *** investigation demonstrates that the capacity perturbation strategy is a feasible strategy for measuring the possible maximum j_(Ac)^(a)of Li/solid electrolyte interface,and hopefully provides good references to explore the critical current density of other types of electrochemical systems.

关键词： All-solid-state lithium batteries Li/solid electrolyte interface Apparent critical current density Interfacial state variation Capacity perturbation strategy

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面向低能耗少切削液的多目标加工参数优化

机械工程学报 2017年第11期53卷 157-163页

作者：马峰张华曹华军武汉科技大学机械自动化学院武汉430081 重庆大学机械传动国家重点实验室重庆400044

数控加工是一种广泛采用的机械制造加工方法,为实现数控加工的高能效,从数控铣削加工的低能耗少切削液两个方面对切削参数进行优化,建立切削加工过程能量消耗目标函数和切削液消耗目标函数。考虑加工过程中数控机床设备性能和加工质量... 详细信息

数控加工是一种广泛采用的机械制造加工方法,为实现数控加工的高能效,从数控铣削加工的低能耗少切削液两个方面对切削参数进行优化,建立切削加工过程能量消耗目标函数和切削液消耗目标函数。考虑加工过程中数控机床设备性能和加工质量的实际约束条件,建立以数控加工的切削速度和进给量以及切削液流速为优化变量,以最低加工能耗和最少切削液消耗为目标的多目标优化模型,并应用非支配排序遗传算法-II对优化模型进行优化求解。最后,通过某具体实例验证了所建模型的有效性。

关键词：数控加工低能耗少切削液切削参数多目标优化

Computational identification of endogenous target mimics for microRNAs in plants and introduction to a plant small RNA analysis toolbox

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Computational identification of endogenous target mimics for...

Preparation of low cobalt-doped LiNiO2 materials by the spray pyrolysis method

第十四届全国植物基因组学大会

作者： huajun Wu Zhimin Wang Ying-Ke ma Meng Wang Xiujie Wang State Key Laboratory of Plant Genomics Institute of Genetics and Developmental BiologyChinese Academy of Sciences

Target mimicry is a recently identified regulatory mechanism for microRNA(miRNA) functions in plants in which the decoy RNAs bind to miRNAs via complementary sequences and therefore block the interaction between miRNA... 详细信息

关键词： target mimicry endogenous microRNA target mimic(eTM) small RNA analysis small RNA biogenesis degradome

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Progress in Natural Science:materials International 2023年第4期33卷 425-432页

作者： Bianzheng You Zhixing Wang Ding Wang Gui Luo Duo Deng Guochun Yan huajun Guo Xinhai Li Wenjie Peng Mingxia Dong Jiexi Wang National Key Laboratory of Energy Metal Resources and New materials Engineering Research Center of the Ministry of Education for Advanced Battery Materials Hunan Provincial Key Laboratory of Nonferrous Value-Added Metallurgy School of Metallurgy and Environment Central South University National and Local Joint Engineering Laboratory for Lithium-ion Batteries and materials Preparation Technology Key Laboratory of Advanced Battery Materials of Yunnan Province Faculty of Metallurgical and Energy Engineering Kunming University of Science and Technology Research Institute BASF Shanshan Battery Materials Co LTD.

LiNiO2(LNO) is recognized as the most promising cathode material for next-generation lithium-ion batteries owing to its highest energy density and economic benefit in the layered oxide cathode materials ***, severe cation disordering, multiple phase transformations and poor lithium-ion diffusion kinetics,which result in rapid degradation of cycling stabilities and rate properties, hinder its further practical applications. Cobalt doping is an effective strategy to address such issues, but the influences of cobalt on LNO materials have not been figured out completely yet. Hence, a systematical investigation of cobalt doping for LiNiO2cathode materials prepared by spray pyrolysis is conducted. The addition of cobalt enhances the stabilities of layered structures and suppresses the cation disordering effectively. The multiple-phase transformations during cycling are also alleviated significantly. Furthermore, cobalt doping can decrease charge transfer resistances and improve lithium-ion diffusion kinetics, especially at high de-lithiation states. As a result, the electrochemical performances are improved comprehensively after cobalt doping. The LNO with optimal doping amount exhibits an improved capacity retention of 78.0% after 100 cycles as compared with 64.9% for pristine LNO, and an outstanding rate performance of 167.2 ma h g-1with the current density of 5 C(1 C = 200 ma g-1).

关键词： Lithium nickel oxides Spray pyrolysis Cobalt doping Phase transformations Lithium-ion diffusion kinetics

Effect of lithium or aluminum substitution on the characteristics of graphite for anode of lithium ion batteries

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Rare Metals 2003年第4期22卷 280-284页

作者： GUO huajun, LI Xinhai, WANG Zhixing, PENG Wenjie, and GUO YongxingCollege of Metallurgical Science and Engineering, Central South University, Changsha 410083, China College of Metallurgical Science and Engineering Central South University Changsha 410083

Modification of graphite for anode of lithium ion batteries is *** of X-ray diffraction shows lithium and aluminum exists as Li compound (CH_3COOLi.2 H_2O) andAl compound (AlD_3) in the graphite, respectiovely. The Brunauer-Emmer-Teller (BET) surface area ofthe modified graphite increases. According to the electrochemical measurements of Li/C cell andprototype Li-ion batteries, the Li-doped graphite has large reversible capacity of 312.2 ma.h/g, lowirreversible capacity of 52.9 ma.h/g, and high initial coulombic efficiency of 85.51 percent. The063448 size prototype battery with Li-doped graphite anode has large discharge capacity of 845 *** good cycling performance. The initial charge/discharge characteristic of Al-doped graphite isclose to those of undoped graphite, but the prototype battery with Al-doped anode shows the bestcycling performance with capacity retention ratio of 94.06 percent at the 200 th cycle.

关键词： Battery graphite dope lithium aluminum

Localization of Low-Frequency magnetic Beacons Based on Genetic Algorithm

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Localization of Low-Frequency Magnetic Beacons Based on Gene...

Electron transportation and optical properties of microstructure TiO2 films:applied in dye-sensitized solar cells

第三十九届中国控制会议

作者： Jiaxin Song Danfeng Sun Zhiyuan Zhao huajun Zhou Hongwei Xia Guangcheng ma Department of control science and engineering Harbin Institute of Technology Shanghai Aerospace Control Technology Institute School of Energy Science and Engineering Harbin Institute of Technology

An autonomous positioning method utilizing the separated magnetic beacons model based on Genetic Algorithm（GA） is proposed in this paper. The low frequency alternating magnetic signal has high penetration ability. Taking advantage of this characteristics, stable positioning service in a severe environment is possible, in which the Global Positioning System（GPS） is not reliable due to multipath effects and non-line-of-sight conditions. The analytical method needs quadrant distinction and is difficult to position points close to the coordinate axis. While using the new method proposed in this paper, the defects are effectively ameliorated. Validated by both theoretical deduction and numerous simulations, the positioning method based on GA has been tested showing accurate localization results for a wide-range measurement.

关键词： Low-frequency magnetic field localization genetic algorithm

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Frontiers of Optoelectronics 2011年第1期4卷 72-79页

作者： Shuangying XU Linhua HU Jiang SHENG Dongxing KOU huajun TIAN Songyuan DAI Key Laboratory of Novel Thin Film Solar Cells Institute of Plasma Physics Chinese Academy of Sciences

Micro-structure of TiO2films in dye-sensitized solar cells（DSSCs） can affect light absorption and electron transportation that impact on the characteristics of currentvoltage（J-V）. In this paper, films with different surface area, pore size and porosity were obtained by adding different ratio of ethyl cellulose（Ec-S） to pastes, and a photo-electric conversion efficiency（η） of 7.55% with a short-circuit current density(Jsc) of 16.81 ma·cm–2was obtained when the ratio of Ec-S was 10∶5. BET results showed that film with this optimum ratio had the most suitable pore size and surface area for good properties of photovoltaic, which had a low reflectivity and high transmission rate, and the efficiency of light utilization was improved. Moreover, measurements by intensitymodulated photocurrent spectroscopy（IMPS） and intensity-modulated photovoltage spectroscopy（IMVS）implied that the electron transport time（τd） increased as the content of Ec-S increased, which was related to the larger surface area. Results of steady-state cyclic voltammetry indicated that diffusion-limited current density(Jlim) of I3–in TiO2film increased with its porosity, which revealed that the transportation of redox mediators in the electrolyte was speeded up.

关键词： micro-structure porosity optical property electron transport dye-sensitized solar cell (DSSC)

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脆弱性研究进展:从理论研究到综合实践

生态学报 2019年第2期39卷 441-453页

作者：杨飞马超方华军中国科学院地理科学与资源研究所资源与环境信息系统国家重点实验室北京100101 中国科学院大学北京100049 中国科学院地理科学与资源研究所生态系统观测与模拟重点实验室北京100101

从20世纪60年代脆弱性概念提出到21世纪脆弱性逐渐成为一门独立的新科学,脆弱性已成为评价地区发展状况的依据以及衡量未来发展规划的判据。基于国内外脆弱性研究文献的回顾和总结,回顾了脆弱性概念起源与发展,梳理了脆弱性评价的定性... 详细信息

从20世纪60年代脆弱性概念提出到21世纪脆弱性逐渐成为一门独立的新科学,脆弱性已成为评价地区发展状况的依据以及衡量未来发展规划的判据。基于国内外脆弱性研究文献的回顾和总结,回顾了脆弱性概念起源与发展,梳理了脆弱性评价的定性和定量方法,科学评述了21世纪以来脆弱性研究的新进展:评价方法创新、多尺度精细评价、多源数据挖掘、关键要素阈值界定、人为活动影响和脆弱性演化机理综合研究。研究发现21世纪以来脆弱性进展迅速,主要特点为多元化、多角度、精细化和综合化,表现为评价数据和方法的多元化;横向空间对比和纵向时间序列的多角度分析;多尺度精细评价;关键要素阈值与演化机理综合研究。未来,脆弱性研究应完善脆弱性概念框架和理论体系,关注耦合系统脆弱性过程与机制,探究脆弱性驱动因素和演化机理,科学界定脆弱性关键要素阈值,挖掘和提取多源遥感数据信息,开展系统脆弱性动态评价和时空分析,实现脆弱性定量评价与综合实践,最终满足国家和地区可持续发展战略的需要。

关键词：脆弱性评价方法耦合系统多源遥感人为活动要素阈值综合实践