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Preparation of chitosan and citric acid crosslinked membrane and its application in quasi-solid supercapacitors

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Rare Metals 2023年第2期42卷 430-437页

作者： Hao-Hang Xu Liang Yue Yang Tang Fan Liu Hong-Jiu Zhu Shu-Juan Bao Institute for Clean energy&Advanced materials School of Materials and EnergySouthwest UniversityChongqing400715China

Quasi-solid electrolytes promote the development of safe and flexible energy storage devices.In this work,a chitosan and citric acid crosslinked membrane is prepared by a freeze-thaw cross-linking method,in which the chemical crosslinking of chitosan and citric acid increase the viscoelastic behavior of the polymer membrane,and the freeze-thaw assist freeze drying process to create abundant interconnected open-pores and three-dimensional(3D)network.Due to the good viscoelasticity,excellent electrolyte loading capacity(596%)and high ion conductivity(7.7×10^(-3)S·cm^(-)1),as quasi-solid electrolyte,our proposed chitosan and citric acid crosslinked membrane helps ZnICCFT-ZnSO4lAC hybrid supercapacitor to delivers wide operating voltage,high specific capacity of 100.5 F·g^(-1)and stable cycle life(93%after1000 cycles),which suggests that our proposed freezethaw assisted freeze drying method has great potential in designing quasi-solid state electrolyte for energy storage device.

关键词： Quasi-solid electrolyte Chitosan Freeze-thaw Hybrid supercapacitor

Promoting hybrid twins structure to reduce yield asymmetry of rolled AZ31 plates by combining side-rolling and torsion

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镁合金学报(英文) 2023年第6期11卷 2096-2105页

作者： Bo Song Meng Wang Ruolan Shi Zhiwen Du Ning Guo Fang Wang Shengfeng Guo School of Materials and Energy Southwest UniversityChongqingChina

In this work,an as-rolled AZ31 square bar with c-axis//ND(normal direction)texture was used.Side-rolling and reciprocating torsion were performed to treat the bar.Microstructure evolution and tensile-compressive properties were investigated in detail.Initial rolled AZ31 bar exhibits a large yield asymmetry along the rolling direction(RD).Reciprocating torsion can generate extension twins to introduce twin boundaries and twin-texture.The twin structure can reduce yield asymmetry.However,only limited regions in the rolled AZ31 bar can be twinned during torsion.Pre-side-rolling along the transverse direction(TD)can generate two texture components(c-axis//TD texture and c-axis//ND texture)by introducing profuse{10–12}twins.Such dual texture components help increase the regions which are favorable for twinning during torsion.Finally,combining side-rolling and reciprocating torsion generates hybrid{10–12}twins structure on the entire cross-section,resulting in a remarkably low yield asymmetry.The relevant mechanisms were discussed in detail.

关键词： AZ31 Square section Torsion Hybrid twins Orientation Yield asymmetry

Texture development and tensile properties of Mg?Yb binary alloys during hot extrusion and subsequent annealing

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Journal of Magnesium and Alloys 2022年第1期10卷 267-283页

作者： Lu Li Cuncai Zhang Hao Lv Chunrong Liu Zhuozhang Wen Jingwen Jiang School of Materials and Energy Southwest UniversityChongqingChina

Ytterbium(Yb)containing magnesium alloys have aroused extensive interest due to their excellent mechanical properties after thermomechanical processing and heat treatment.Unfortunately,the sole effect of Yb addition on the microstructure and mechanical properties of pure Mg matrix remains uncertain to date.In this work,the effects of Yb concentration on the texture development and tensile properties of pure Mg matrix during hot extrusion and the subsequent annealing were systematically investigated.The results revealed that the constitutional supercooling induced by Yb addition refined the as-cast microstructure but exerted a negligible effect on the original columnar grain morphology.When extruded at 300°C,the dynamic recrystallization(DRX)process was considerably retarded.The in-grain misorientation axes(IGMA)analysis combined with TEM observation indicated that non-basal slips operated with increasing Yb concentration.Specifically,the prismaticslip should be robustly activated in Mg-1.0 Yb extrudate,promoting the formation of the texture with{10?10}plane normal to the extrusion direction(ED),while for the Mg?2.0 Yb counterpart,the increased activity of pyramidalslip and the relaxation of basal/dislocations generated an ED-tilted texture component.The preferential grain growth dominated the subsequent annealing texture development at 400°C when a comparable grain size was achieved.An obvious ED-tilted texture intensity with the peak aroundwas observed in Mg-2.0 Yb alloy,which was primarily caused by grains with the basal orientation vanished and with the non-basal orientations intensified due to a higher concentration of Yb solute.Favored by the grain refinement,the Mg-2.0 Yb extrudate exhibited a high tensile yield strength of 304±3.5 MPa,while the subsequently annealed counterpart presented a favorable elongation to failure of 14.8±1.2%,which mainly due to the homogeneous grain structure,weak ED-tilted texture,and dissolution of coarse phases after high-temperature annealing.

关键词： Magnesium alloy Ytterbium Texture development Tensile properties

Tetraphenylethene-based hole transporting material for highly efficient and stable perovskite solar cells

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Science China Chemistry 2024年第6期67卷 2009-2015页

作者： Peng Wang Pei Yuan Chenghao Ge Rongjun Zhao Lin Xie Yong Hua School of Materials and Energy Yunnan UniversityKunming650091China

2,2,7,7-Tetrakis-(N,N-di-p-methoxyphenylamine)-9,9-spirobifluorene(Spiro-OMeTAD)has been identified as the most widely used and effective hole transporting material(HTM)in perovskite solar cells(PSCs).However,the complicated multistep synthesis and low intrinsic hole mobility of Spiro-OMe TAD limit its commercialized application.Therefore,developing highly efficient HTMs with less synthetic steps becomes increasingly important.Moreover,understanding hot carriers transfer dynamics at the interface of perovskite layer and hole transport layer is crucial for further enhancing PSCs performance towards Shockley-Queisser limit,which still lacks full investigation to date.Herein,a new HTM based on tetraphenylethene(WP1)was successfully synthesized by a simple one-step reaction process.It was found that WP1-based HTM exhibits more matched energy level,higher hole mobility and conductivity than those of the control Spiro-OMe TAD.The femtosecond transient absorption results reveal that the transfer rate of hot holes in perovskite/WP1 sample is four times higher than that of perovskite/Spiro-OMeTAD,thereby helping enhance the device performance.Consequently,the efficiency of PSCs is enhanced to 24.04%(WP1)from 22.85%(Spiro-OMeTAD).Moreover,the un-encapsulated device prepared with WP1 exhibits better long-term stability,retaining 87%of its initial PCE value after storing for 72 days under air environment,while the reference device shows76%of its initial value.This work indicates that simple tetraphenylethene-based organic small molecule could be a very promising HTM candidate for highly efficient PSCs,and gives some significant insights for understanding intrinsic hot carriers transfer dynamics in device.

关键词： tetraphenylethene hole transporting material perovskite solar cells mobility hot carrier

Ni_(3)FeN anchored on porous carbon as electrocatalyst for advanced Li-S batteries

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稀有金属：英文版 2023年第2期42卷 515-524页

作者： Shi-Min Wang Hua-Ni Li Gen-Fu Zhao Lu-Fu Xu Dang-Ling Liu Yong-Jiang Sun Hong Guo School of Materials and Energy Yunnan UniversityKunming650091China

Lithium-sulfur(Li-S)battery is one of the newgeneration energy storage systems with great potential.However,the development of Li-S battery now is hampered by the shuttle effect and depressed redox kinetics.Herein,we report a composite of Ni_(3)FeN nanoparticles anchored in grid-like porous carbon(PC)spheres as an effective cathode electrocatalyst with simultaneous polysulfide trapping and rapid polysulfides conversion in Li-S battery.The multi-cavity structure of PC with high-efficiency encapsulation ability can significantly improve sulfur utilization and confinement.Furthermore,Ni_(3)FeN nanoparticles embedded in PC cavities render highly active catalytic sites to promote the redox conversion of solvated poly sulfide,as revealed by the electrochemical results.Moreover,the catalytic mechanism is further analyzed through density functional theory calculations and in-situ Fourier transform infrared analysis.As a result,PC@Ni_(3)FeN@S cathode delivers an outstanding capacity of 1294mAh·g^(-1)at 0.1C and low decay rates of 0.10%per cycle over 500 cycles at 0.5C.

关键词： Porous structures Ni_(3)FeN nanoparticle Polysulfides electrocatalyst Lithium-sulfur(Li-S)batteries

钠离子电池用O3型层状NaCrO_(2)正极材料在高温下的优异倍率性能和结构演变

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中国科学:材料科学(英文版) 2023年第9期66卷 3445-3452页

作者：孟祥聪梁锦记梁敏李文雅林琛翰柯曦施志聪刘丽英 School of Materials and Energy Guangzhou Key Laboratory of Low-dimensional Materials and Energy Storage DevicesGuangdong University of TechnologyGuangzhou 510006China

为满足钠离子电池的实际应用,本文采用一种低能耗方法合成了层状NaCrO_(2)正极材料.合成的O3型NaCrO_(2)正极材料即使在高温下也表现出优异的倍率性能.在60℃,100 C倍率下测试时比容量高达47.4 mA h g^(-1),这是由于适当的高温促进了Na^... 详细信息

为满足钠离子电池的实际应用,本文采用一种低能耗方法合成了层状NaCrO_(2)正极材料.合成的O3型NaCrO_(2)正极材料即使在高温下也表现出优异的倍率性能.在60℃,100 C倍率下测试时比容量高达47.4 mA h g^(-1),这是由于适当的高温促进了Na^(+)的扩散.然而,与室温下良好的循环性能相比,高温循环过程中NaCrO_(2)发生了复杂的不可逆结构演变,这导致NaCrO_(2)高温循环性能下降.这项工作将推动具有优异倍率性能、尤其是优异高温倍率性能的钠离子电池层状氧化物正极材料的产业化发展,同时加深对层状氧化物正极材料高温容量衰减机制的理解.

关键词：钠离子电池正极材料倍率性能层状氧化物高温循环性能容量衰减结构演变低能耗

原位构建具有铋合金纳米片的三维导电核壳纳米网络和电子结构用于高效电催化CO_(2)还原

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Science China materials 2023年第6期66卷 2266-2273页

作者：胡延杰王心英张嘉城张家明张杨涛梁嘉文李运勇 School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006China

由于CO_(2)传质的限制,在H型电池中,具有高法拉第效率(>90%)和大电流密度(>150 mA cm^(-2))的电催化CO_(2)还原(CO_(2)RR)制备HCOOH燃料的过程非常具有挑战性.在本文中,我们报道了一种在泡沫Cu上原位构建具有三维(3D)多孔网络核壳纳米... 详细信息

由于CO_(2)传质的限制,在H型电池中,具有高法拉第效率(>90%)和大电流密度(>150 mA cm^(-2))的电催化CO_(2)还原(CO_(2)RR)制备HCOOH燃料的过程非常具有挑战性.在本文中,我们报道了一种在泡沫Cu上原位构建具有三维(3D)多孔网络核壳纳米线结构的优异CO_(2)RR电催化剂.核壳结构由Cu纳米线核和Sb-Bi合金壳组成(Cu@Sb_(x)Bi_(y)NWs/Cu).制备的Cu@Sb_(x)Bi_(y)NWs/Cu具有171.3mA cm^(-2)的高电流密度以及92%的HCOOH法拉第效率,就电流密度而言优于几乎所有报道的铋基催化剂.理论研究表明,Sb的引入使Bi的电子态提高到接近费米能级,与纯Bi表面相比,^(*)OCHO中间体更易吸附在Sb-Bi界面上,从而加速CO_(2)还原.此外,Sb_(0.1)Bi_(1)与纯Bi相比具有更强的键能,这有利于催化剂在反应过程中的稳定性.Sb_(0.1)Bi_(1)合金和3D导电核壳纳米网络的形成更有利于快速电子转移,并在反应过程中暴露出更多的活性位点,从而获得更好的催化活性.这项工作为设计用于能量转换的高活性铋基催化剂提供了理论依据.

关键词：电催化电子转移费米能级电子态大电流密度核壳能量转换纳米网络

Fe-N co-doped coral-like hollow carbon shell toward boosting peroxymonosulfate activation for efficient degradation of tetracycline: Singlet oxygen-dominated non-radical pathway

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Journal of Environmental Sciences 2023年第4期126卷 470-482页

作者： Wenjin Chen Jin Huang Yaqian Shen Ke Zhu Lele Lei Hongmei He Yushi Ai School of Materials and Energy University of Electronic Science and Technology of ChinaChengdu 611731China

Fe-N co-doped coral-like hollow carbon shell (Fe-N-CS) was synthesized via a simply impregnation-pyrolysis method.The Fe-N-CS showed an excellent ability for activating peroxymonosulfate (PMS),which could degrade about 93.74%tetracycline (20 mg/L) in 12 min.The Fe-N-CS/PMS system exhibited a good anti-interference capacity of various pH,inorganic anions,HA and different water qualities.More importantly,the Fe nanoparticles were anchored uniformly in the carbon layer,effectively limiting the metal leaching.The quenching tests and electron spin resonance (ESR) manifested that non-radical singlet oxygen (1O_(2))was the main reactive oxygen species (ROS) for TC degradation.The mechanism study showed that Fe nanoparticles,defect and graphite N played a key role in activating PMS to produce ROS.Moreover,three probable degradation pathways were proposed by using LC-MS measurements.Generally,this work had a new insight for the synthesis of heterogeneous Fe-N-C catalysts in the advanced oxidation process based on PMS.

关键词： Fe-N co-doped Carbon shells Peroxymonosulfate Tetracycline Singlet oxygen

金属有机框架结构原位衍化多孔炭基体封装的MnO颗粒及其锂离子电容器应用

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Science China materials 2022年第1期65卷 59-68页

作者：蒋嗣鹏贠士林曹海杰张志强冯红彬陈海潮 Institute of materials for energy and Environment School of Materials Science and EngineeringQingdao UniversityQingdao 266071China

转换型阳极材料因较高的比容量在储锂方面具有较大的应用潜力,但是严重的体积膨胀和低电导率限制了此类电极材料的倍率和循环性能.本研究设计了一种双金属锌锰基金属有机骨架(ZnMn-MOF)材料,并成功地将其转化成多孔炭封装的MnO颗粒(MnO/... 详细信息

转换型阳极材料因较高的比容量在储锂方面具有较大的应用潜力,但是严重的体积膨胀和低电导率限制了此类电极材料的倍率和循环性能.本研究设计了一种双金属锌锰基金属有机骨架(ZnMn-MOF)材料,并成功地将其转化成多孔炭封装的MnO颗粒(MnO/PC)复合电极材料.配位锌组元的模板和活化作用赋予PC基体多孔结构,能够显著地提高PC基体与MnO颗粒的相容性,导致MnO颗粒完全封装于PC基体中.更重要的是,PC基体的多孔结构为缓冲MnO的体积变化提供了足够的空间,经过反复的充放电循环后MnO仍完全封装于PC基体而不发生破裂乃至破碎.研究结果表明,MnO/PC同时具有较高的电荷储存容量、优异的倍率性能和超长的循环稳定性.MnO/PC在0.1 A g^(-1)时具有768 mA h g^(-1)的比容量,在0.7 A g^(-1)时其比容量仍能保持487 mA h g^(-1),并且在0.3 A g^(-1)循环500次后性能未衰减.值得关注的是,MnO/PC在锂离子电容器中与电容型活性炭电极表现出良好的匹配性,组装的锂离子电容器在比功率为210Wkg^(-1)时实现了153.6Wh kg^(-1)的比能量,并且在比功率为63.0kW kg^(-1)时仍能维持71.8W h kg^(-1)的比能量.

关键词：锂离子电容器活性炭电极阳极材料金属有机骨架比功率多孔结构转换型多孔炭