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ZIF-derived holey electrode with enhanced mass transfer and N-rich catalytic sites for high-power and long-life vanadium flow batteries

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Journal of Energy Chemistry 2022年第9期31卷 545-553,I0015页

作者： Yongbin Liu Lihong Yu xin Liu Le Liu jingyu xi Institute of Materials Research Shenzhen International Graduate SchoolTsinghua UniversityShenzhen 518055GuangdongChina School of Materials&Environmental Engineering Shenzhen PolytechnicShenzhen 518055GuangdongChina

Electrode materials with good redox kinetics,excellent mass transfer characteristics and ultra-high stability play a crucial role in reducing the life-cycle cost and prolonging the maintenance-free time of the vanadium flow batteries(VFB).Herein,a nitrogen-doped porous graphite felt electrode(N-PGF)is proposed by growing ZIF-67 nanoparticles on carbon fibers and then calcinating and acid *** multi-scale structure of“carbon fiber gap(electrolyte flow),micro/nano pore(active species diffusion)and Nitrogen active center(reaction site)”in N-PGF electrode effectively increases the catalytic sites and promotes mass transfer *** electrode design makes the battery show excellent rate performance and ultra-high cycling *** peak power density of the battery reaches 1006 mW cm^(-2).During 1000 cycles at 150 mA cm^(-2),the average discharge capacity and average discharge energy of N-PGF increase substantially by 11.6%and 23.4%compared with the benchmark thermal activated graphite felt,*** excitingly,after ultra-long term(5000 cycles)operation at an ultra-high current density(300 mA cm^(-2)),N-PGF exhibits an unprecedented energy efficiency retention(99.79%)and electrochemical performance stability.

关键词： Vanadium flow battery Multi-scale pore electrode Graphite felt Nitrogen-doping Cycling stability

PEO-LiClO_4-ZSM5 composite polymer electrolyte(IV):Polarized optical microscopy study

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Science China Chemistry 2005年第6期48卷 574-579页

作者： xi jingyu QIU xinping ZHU Wentao CHEN Liquan Department of Chemistry Tsinghua University Beijing 100084 China Department of Chemistry Tsinghua University Beijing 100084 China Department of Chemistry Tsinghua University Beijing 100084 China Department of Chemistry Tsinghua University Beijing 100084 China

Polarized optical microscopy (POM) results show that ZSM5 has great influence on both the nucleation stage and the growth stage of PEO spherulites. Part of ZSM5 particles can act as the nucleus of PEO spherulites and thus increase the amount of PEO spherulites. On the other hand, ZSM5 can restrain the recrystallization tendency of PEO chains through Lewis acid-base interaction and hence decrease the growth speed of PEO spherulites. The increasing amount of PEO spherulites, decreasing size of PEO spherulites, and the incomplete crystalliza-tion are all beneficial for creating more continuous amorphous phases of PEO, which is very important for the transporting of Li+ ions. An adequate amount of ZSM5 can enhance the room temperature ionic conductivity of PEO-LiClO4 based polymer electrolyte for more than two mag-nitudes.

关键词： composite polymer electrolyte, poly (ethylene oxide), ZSM-5, polarized optical microscopy, spherulites.

Broad temperature adaptability of vanadium redox flow battery-part4:Unraveling wide temperature promotion mechanism of bismuth for V^(2+)/V^(3+) couple

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Journal of Energy Chemistry 2018年第5期27卷 1333-1340页

作者： Yuchen Liu Feng Liang Yang Zhao Lihong Yu Le Liu jingyu xi The State Key Laboratory of Refractories and Metallurgy School of Chemistry and Chemical Engineering Wuhan University of Science and Technology Institute of Green Chemistry and Energy Graduate School at Shenzhen Tsinghua University School of Applied Chemistry and Biological Technology Shenzhen Polytechnic

Vanadium flow battery （VFB） is a fast going and promising system for large-scale stationary energy stor- age. However, drawbacks such as low power density and narrow temperature window caused by poor catalytic activity of graphite felt （GF） electrodes limit its worldwide application. In this paper, bismuth, as a low-cost, no-toxic and high-activity electrocatalyst, is used to modify the thermal activated GF （TGF） via a facile hydrothermal method. Bismuth can effectively inhibit the side reaction of hydrogen evolution in wide temperature range, while promoting the V2＋/V3＋ redox reaction. As a result, the VFB assembled with Bi/TGF as negative electrode demonstrates outstanding rate performance under the current density up to 400 mAcm-2, as well as a long-term stability over 600 charging/discharging cycles at a high cur- rent density of 150mA cm-2. Moreover, it also shows excellent temperature adaptability from -10 ℃ to 50 ℃ and high durability for life test at the temperature of 50 ℃.

关键词： Vanadium flow battery Graphite felt electrode Bismuth Hydrogen evolution reaction Wide temperature

Synthesis,characterization and properties of diamidodisilanes and azocyclosilane

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Chinese Science Bulletin 2005年第15期50卷 1576-1581页

作者： CUI Mengzhong ZHAO Yixin ZHANG Bin xi jingyu WANG Shuguang TANG xiaozhen School of Chemistry and Chemical Technology Shanghai Jiao Tong University Shanghai 200240 China College of Chemistry and Biology Technology Yantai UniversityYantai 264005 China

Several diamidodisilanes and azocyclosilane were prepared from the resultants of Wurtz coupling reaction between dichlorosilane and sodium and characterized by 1H NMR and FT-IR. The two split peaks of the stretching vibration bonds of Si-H bonds in compounds 1 and 3 were firstly found at ～2163 cm-1 and ～2100 cm-1 respectively. The density functional theory was adopted to calculate the several stable geometrical isomerism structures of compounds 1 and 3. The results of the calculations show that the peak split of Si-H bonds stretching vibration absorption was caused by the different geometrical isomers of the compounds and the calculated IR spectra of compounds 1 and 3 are much closer to the experimental results. The processes of hydrolysis and polycondensation reactions of the synthetic compounds were studied by FT-IR. At the same time, the transition of Si-H bonds split peaks was observed in this procedure. As the results of the hydrolysis and condensation reactions, a new type of organic silicon polymer, polyoxydisilane was obtained, which presents the photoluminescence of the polysilanes.

关键词：乙硅烷拉伸振动吸收特性耦合反应水解作用

Multiple-dimensioned defect engineering for graphite felt electrode of vanadium redox flow battery

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Carbon Energy 2024年第2期6卷 143-153页

作者： Yingqiao Jiang Yinhui Wang Gang Cheng Yuehua Li Lei Dai Jing Zhu Wei Meng jingyu xi Ling Wang Zhangxing He School of Chemical Engineering North China University of Science and TechnologyTangshanChina Tsinghua Shenzhen International Graduate School Institute of Materials ResearchTsinghua UniversityShenzhenChina

The scarcity of wettability,insufficient active sites,and low surface area of graphite felt(GF)have long been suppressing the performance of vanadium redox flow batteries(VRFBs).Herein,an ultra-homogeneous multipledimensioned defect,including nano-scale etching and atomic-scale N,O codoping,was used to modify GF by the molten salt ***_(4)Cl and KClO_(3) were added simultaneously to the system to obtain porous N/O co-doped electrode(GF/ON),where KClO_(3) was used to ultra-homogeneously etch,and O-functionalize electrode,and NH4Cl was used as N dopant,***/ON presents better electrochemical catalysis for VO_(2)+/VO_(2)+ and V3+/V2+ reactions than only O-functionalized electrodes(GF/O)and *** enhanced electrochemical properties are attributed to an increase in active sites,surface area,and wettability,as well as the synergistic effect of N and O,which is also supported by the density functional theory ***,the cell using GF/ON shows higher discharge capacity,energy efficiency,and stability for cycling performance than the pristine cell at 140 mA cm^(−2) for 200 ***,the energy efficiency of the modified cell is increased by 9.7% from 55.2% for the pristine cell at 260 mA cm^(−2).Such an ultra-homogeneous etching with N and O co-doping through“boiling”molten salt medium provides an effective and practical application potential way to prepare superior electrodes for VRFB.

关键词： graphite felt molten salt N O co-doping ultra-homogeneous etching vanadium redox flow battery

RuO_(2) clusters derived from bulk SrRuO_(3):Robust catalyst for oxygen evolution reaction in acid

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Nano Research 2022年第3期15卷 1959-1965页

作者： Muwei Ji xin Yang Shengding Chang Wenxing Chen Jin Wang Dongsheng He Yao Hu Qian Deng You Sun Bo Li jingyu xi Tomoaki Yamada Jiatao Zhang Hai xiao Caizhen Zhu Jia Li Yadong Li College of Materials Science and Engineering Shenzhen UniversityShenzhen 518060China Institute of Low-Dimensional Materials Genome Initiative College of Chemistry and Environmental Engineering of Shenzhen UniversityShenzhen 518060China Tsinghua Shenzhen International Graduate School Tsinghua UniversityShenzhen 518055China Beijing Key Laboratory of Construction Tailorable Advanced Functional Materials and Green Applications School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Materials Characterization and Preparation Center Southern University of Science and TechnologyShenzhen 518055China Department of Energy Engineering Nagoya UniversityFuro-choChikusa-kuNagoya 464-8603Japan Department of Chemistry Tsinghua UniversityBeijing 100084China

Developing highly efficient oxygen evolution reaction(OER)catalyst for the acidic corrosive operating conditions is a challenging ***,we report the synthesis of uniform RuO_(2)clusters with~2 nm in size via electrochemical leaching of Sr from SrRuO_(3) ceramic in *** RuO_(2)clusters exhibit ultrahigh OER activity with overpotential of~160 mV at 10 mA·cm_(geo)^(−2) in 1.0 M HClO4 solution for 30-h *** extended X-ray absorption fine structure measurement reveals enlarged Jahn-Teller distortion of Ru-O octahedra in the RuO_(2)clusters compared to its bulk *** function theory calculations show that the enhanced Jahn-Teller distortion can improve the intrinsic OER activity of RuO_(2).

关键词： oxygen evolution reaction RuO_(2)cluster electrochemical leaching acid solution

Ni对Cu/ZnO基甲醇裂解催化剂的促进机制

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化学学报 2002年第3期60卷 419-426页

作者：席靖宇王卫平吕功煊中国科学院兰州化学物理研究所

通过XRD ,BET ,In situXPS等表征技术对Cu/ZnO基甲醇裂解制氢催化剂进行了详细的研究 .XRD结果表明 ,Cu Zn合金的生成是Cu/ZnO基催化剂在反应初期快速失活的主要原因 ;XRD ,BET和N2 O滴定实验结果表明 ,Ni助剂可能是通过提高Cu0 活性物... 详细信息

通过XRD ,BET ,In situXPS等表征技术对Cu/ZnO基甲醇裂解制氢催化剂进行了详细的研究 .XRD结果表明 ,Cu Zn合金的生成是Cu/ZnO基催化剂在反应初期快速失活的主要原因 ;XRD ,BET和N2 O滴定实验结果表明 ,Ni助剂可能是通过提高Cu0 活性物种的分散度并维持Cu0 活性物种在催化反应过程中的稳定性而使Cu/Zn/Ni催化剂的活性及稳定性大幅度提高 .In situXPS结果表明 ,Ni助剂的加入可以诱导Cu/Zn/Ni催化剂表面在甲醇裂解反应过程中出现Cu+ ,从而由Cu0 /Cu+ 共同构成催化剂的活性中心 ,并最终导致Cu/Zn/Ni催化剂的高活性 .

关键词： Ni Cu/ZnO 甲醇裂解催化剂促进机制氢气表征铜镍氧化锌

含功能性羟基的温敏性聚(N-异丙基丙烯酰胺)微凝胶的制备及性能研究

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高分子学报 2005年第2期15卷 197-202页

作者：马晓梅朱路席靖宇赵喜安唐小真上海交通大学化学化工学院

采用两步合成路线合成了二缩三乙二醇单甲基丙烯酸酯 (TREGMA) ,并对其结构进行了表征 ;利用无皂乳液聚合法使N 异丙基丙烯酰胺 (NIPAM)、TREGMA和N ,N 亚甲基双丙烯酰胺 (BA)交联共聚 ,制备了含有功能性羟基的温敏性微凝胶 .微凝胶的... 详细信息

采用两步合成路线合成了二缩三乙二醇单甲基丙烯酸酯 (TREGMA) ,并对其结构进行了表征 ;利用无皂乳液聚合法使N 异丙基丙烯酰胺 (NIPAM)、TREGMA和N ,N 亚甲基双丙烯酰胺 (BA)交联共聚 ,制备了含有功能性羟基的温敏性微凝胶 .微凝胶的去溶胀性能研究表明 ,TREGMA的引入使得微凝胶的体积相转变温度得到提高 ,同时所制得微凝胶具有较好的温敏性 .该类微凝胶有望成为良好的生物医用材料 .

关键词：聚(N-异丙基丙烯酰胺) 性能研究功能性制备羟基亚甲基双丙烯酰胺无皂乳液聚合法甲基丙烯酸酯二缩三乙二醇温敏性微凝胶生物医用材料相转变温度合成路线交联共聚体积

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钒电池电解液体积变化规律研究

化学学报 2011年第2期69卷 132-136页

作者：赵永涛席靖宇滕祥国武增华邱新平清华大学深圳研究生院绿色化学电源实验室深圳518055 清华大学化学系北京100084 哈尔滨工业大学(威海)应用化学系威海264209

研究了钒电池在使用阳离子交换膜稳定运行过程中电解液体积的变化情况,分析了影响因素,并总结了变化规律.离子的电迁移使电解液体积随充放电容量的变化线性改变,充电过程正极电解液体积线性减小,负极电解液体积线性增大;放电过程反之.... 详细信息

研究了钒电池在使用阳离子交换膜稳定运行过程中电解液体积的变化情况,分析了影响因素,并总结了变化规律.离子的电迁移使电解液体积随充放电容量的变化线性改变,充电过程正极电解液体积线性减小,负极电解液体积线性增大;放电过程反之.多次充放电循环过程中,钒离子的净渗透方向是由负极到正极,水的净变化方向与钒离子相同,最终使得多次循环过程正极电解液的体积逐渐增加.

关键词：钒电池电解液体积变化率离子电迁移率