Progress in Electrolyte Engineering of Aqueous Batteries in a Wide Temperature Range

Aqueous rechargeable batteries are safe and environmentally friendly and can be made at a low cost;as such,they are attracting attention in the field of energy storage.However,the temperature sensitivity of aqueous batteries hinders their practical application.The solvent water freezes at low temperatures,and there is a reduction in ionic conductivity,whereas it evaporates rapidly at high temperatures,which causes increased side reactions.This review discusses recent progress in improving the performance of aqueous batteries,mainly with respect to electrolyte engineering and the associated strategies employed to achieve such improvements over a wide temperature domain.The review focuses on fi ve electrolyte engineer-ing(aqueous high-concentration electrolytes,organic electrolytes,quasi-solid/solid electrolytes,hybrid electrolytes,and eutectic electrolytes)and investigates the mechanisms involved in reducing the solidifi cation point and boiling point of the electrolyte and enhancing the extreme-temperature electrochemical performance.Finally,the prospect of further improving the wide temperature range performance of aqueous rechargeable batteries is presented.

熔融沉积成型参数对改性聚乳酸冲击性能的影响

以聚乳酸(PLA)为基体、热塑性聚氨酯(TPU)和甲基丙烯酸甲酯-有机硅-苯乙烯共聚物(S-2001)为增韧剂,通过熔融共混法制备了改性PLA 3D打印线材,采用正交试验探索了底板温度、打印温度、沉积方式、打印层厚和打印速度等熔融沉积成型(FDM)参数对改性PLA冲击性能的影响。结果表明,当底板温度为90℃,喷嘴温度为190℃,沉积方式为45°/45°,打印层厚为0.4 mm和打印速度为45 mm/s时,FDM试样的冲击强度达到最大值,而且打印层厚和沉积方式对改性PLA FDM试样的冲击性能影响显著;扫描电镜分析表明增加打印层厚有利于材料吸收冲击功,奇数层与偶数层之间的不同沉积角度对试样冲击强度的提高影响不一,45°/45°为宜;同时,最优工艺的FDM试样的冲击强度比注塑试样低,为注塑试样的71.4%。

基于熔融沉积成型的聚乳酸/热塑性聚氨酯的制备与表征

通过熔融共混法制备了不同质量比的聚乳酸(PLA)/热塑性聚氨酯(TPU)共混物。采用旋转流变仪、扫描电镜、电子万能试验机及差示扫描量热仪等研究了共混物的动态流变行为、微观形貌、力学性能和热性能,并通过线材机牵引成直径为1.75 mm左右的线材进行熔融沉积成型(FDM)。结果表明,加入TPU后能提高材料的储能模量,使熔体弹性增强,利于熔融铺丝。TPU能改善材料的冲击韧性,且随着TPU含量的增加而增大。另外,PLA/TPU熔融共混后体系的结晶能力下降,对熔融沉积成型收缩翘曲具有抑制作用。当TPU质量分数为10%时,线材的熔融沉积成型效果最好。

超高分子量聚乙烯摩擦磨损行为及拉曼成像

以未交联超高分子量聚乙烯(UHMWPE)和交联UHMWPE为研究对象,探讨2种材料在滑动和滚动摩擦条件下的摩擦磨损行为,重点采用拉曼成像的方法分析了磨损表面的结晶度分布和取向分布。结果表明,交联降低了UHMWPE的摩擦系数和磨损率;在滑动摩擦下,交联使UHMWPE的耐磨性提高了96%,在滚动摩擦方式下,交联使UHMWPE的耐磨性提高了41%;拉曼光谱成像表明,UHMWPE和交联UHMWPE磨损区域的表面结晶度都比未摩擦区域高;在滑动摩擦下,纯UHMWPE和交联UHMWPE均发生了取向,而在滚动摩擦下两者都没有发生明显的取向。

用于氯乙烯废气高效催化氧化的Ce-Cu-W-O微球的新颖合成

含氯挥发性有机物(CVOC)氯乙烯(VC)出现在工业生产聚氯乙烯(PVC)的尾气中,其具有高毒性和环境稳定性,若直接排放到大气中,会引起环境污染和威胁人类健康,因此有效的去除CVOC至关重要.在众多处理技术,催化氧化法具有反应温度低、能耗少、避免二次污染等优点,因而备受关注.用于CVOC催化氧化的催化剂包含贵金属和非贵金属催化剂,后者因为具有较低的成本和较好的抗氯中毒能力而广受研究.CVOC氧化催化剂通常需要具备酸性位和氧化还原位,酸性位用来吸附活化CVOC分子,而氧化还原位对应深度氧化能力.过渡金属氧化物CeO2具有良好的储氧能力和氧化还原性而被作为催化材料应用于CVOC的催化氧化,但深度氧化能力不佳.研究发现,复合Cu氧化物可以提高CeO2的氧化还原性,继而提升催化剂对CVOC的氧化能力,但酸性不足仍然限制了氯乙烯低温完全氧化的能力.为此,可以尝试在Ce-Cu复合氧化物中引入氧化钨来提高催化剂的酸性,但往往削弱了催化剂的氧化还原性,且酸性位大多分布在催化剂体相中,无法充分发挥其对VC分子的吸附活化.基于此,本文利用钨酸铵随水热时间延长而逐渐溶解并扩散W离子的这一特性,通过一步水热法设计合成了表面富集W物种和高分散精细Cu物种的Ce-Cu-W-O微球,其相对于Ce-Cu-O催化剂具有同时更好的酸性和氧化还原性,从而表现出对VC优异的深度氧化能力和热稳定性.通过扫描电子显微镜,X射线能谱和X射线衍射分析,我们解析了Ce-Cu-W-O微球上不同元素组分在水热过程中的生长阶段和物相状态.NH3程序升温脱附分析验证了W物种的添加将提高Ce-Cu氧化物的酸性.H2程序升温还原分析表明,共沉淀方式引入W会降低Ce-Cu氧化物的氧化还原性,而水热一步法制备Ce-Cu-W-O微球的氧化还原性却得到了改善,归因细小晶粒尺寸CuO物种的生成.此外,拉曼光谱和XPS分析表明,HW-CeCuW催化剂具有更多的氧空位,有利于活性氧物种的迁移.因此,Ce-Cu-W-O微球表现出优异的低温氧化活性(250 oC时的反应速率为2.01×10^-7 mol/(gcat·s))和较高的HCl选择性.同时,Ce-Cu-W-O微球经三次循环测试后性能仅略微下降,且在300℃下进行72 h的耐久性实验中保持稳定的VC转化率和矿化率,表明其良好的热稳定性.本合成策略可以为高效的CVOC催化氧化的金属氧化物催化剂的设计和合成提供一些新思路.

·CO3^–在基于太阳光驱动的TiO2-贝壳粉降解盐酸四环素中的作用:降解机理和转化路径

抗生素的滥用和不当排放对水陆生生态系统造成了严重威胁,在世界各地水环境污染物调研中普遍检测到盐酸四环素的存在.如何解决水体中高稳定、难降解的盐酸四环素污染问题是当前环境领域重点研究的课题之一.在各种去除方法中,利用光化学反应生成活性氧物种如·CO3–,·OH,·O2–,·SO4–和1O2等实现对有机污染物的降解在众多研究方法中脱颖而出.·CO3–在水体中具有较高的稳态浓度且其对有机物降解具有高选择性.CO32–或HCO3–与活性物种如·OH, h+,·O2–,·SO4–等反应可以生成·CO3–.传统的半导体光催化剂TiO2在光照下会产生·OH,·O2–及h+等活性物种,能有效地降解有机污染物,已有研究发现添加CO32–/HCO3–有利于提高UV/TiO2体系降解有机物的反应速率.贝壳中含有95%以上的碳酸钙,由于其具有低成本、生态友好、无毒性等特点而越来越受到人们的关注.贝壳与TiO2复合,利用贝壳在水相中提供的CO32–/HCO3–与TiO2在光照下产生的·OH,·O2–及h+等活性物种反应生成·CO3–促进光催化反应速率的提高,对盐酸四环素的有效去除具有显著意义.本文通过溶胶-凝胶法合成TiO2-贝壳粉,采用X射线衍射、扫描电子显微镜、透射电子显微镜、X射线光电子能谱、红外光谱和氮气吸附-脱附测试等技术对所得样品进行了表征.考察了TiO2-贝壳粉在模拟太阳光下对盐酸四环素的降解性能.结果表明,在模拟太阳光的作用下, 40%TS-300在30 min内能降解94.0%的盐酸四环素,优于纯TiO2的降解效率(88.6%).通过自由基捕获实验比较了TiO2和TiO2-贝壳粉体系降解盐酸四环素机理的差异,在TiO2光催化降解盐酸四环素体系中,·O2–和h+是主要活性物种.而在TiO2-贝壳粉体系中, TiO2在光照条件下产生的·OH,·O2–及h+通过与贝壳粉在水相中提供的CO32–/HCO3–进一步产生·CO3–,·CO3–、·O2–和h+协同作用实现盐酸四环素的有效降解.采用HRESI-TOF-MS研究了40%TS-300光降解盐酸四环素的中间转化产物,提出TiO2-贝壳粉光降解盐酸四环素可能的降解路径.对40%TS-300样品进行了光降解盐酸四环素长效循环测试,结果表明该样品能够保持稳定有效的降解盐酸四环素性能,此为该材料今后的潜在应用奠定了可靠基础.

Research progress in electrospinning engineering for all-solid-state electrolytes of lithium metal batteries

Owing to safety issue and low energy density of liquid lithium-ion batteries(LIBs),all-solid-state lithium metal batteries(ASLMBs)with unique all-solid-state electrolytes(SEs)have attracted wide attentions.This arises mainly from the advantages of the SEs in the suppression of lithium dendrite growth,long cycle life,and broad working temperature range,showing huge potential applications in electronic devices,electric vehicles,smart grids,and biomedical devices.However,SEs suffer from low lithiumion conductivity and low mechanical integrity,slowing down the development of practical ASLMBs.Nanostructure engineering is of great efficiency in tuning the structure and composition of the SEs with improved lithium-ion conductivity and mechanical integrity.Among various available technologies for nanostructure engineering,electrospinning is a promising technique because of its simple operation,cost-effectiveness,and efficient integration with different components.In this review,we will first give a simple description of the electrospinning process.Then,the use of electrospinning technique in the synthesis of various SEs is summarized,for example,organic nanofibrous matrix,organic/inorganic nanofibrous matrix,and inorganic nanofibrous matrix combined with other components.The current development of the advanced architectures of SEs through electrospinning technology is also presented to provide references and ideas for designing high-performance ASLMBs.Finally,an outlook and further challenges in the preparation of advanced SEs for ASLMBs through electrospinning engineering are given.

退役动力电池回收利用的现状及碳核算研究进展

新能源汽车行业的蓬勃发展促使动力电池报废量大幅上涨,产生数量庞大的固体废物。通过梯次利用和回收再生对退役动力电池进行再利用不仅能够实现有价金属的资源化再利用,还可降低碳排放和生产成本,是推进循环经济发展和资源集约利用的关键环节,对于落实“双碳”战略和推进生态文明建设具有重要意义。目前,研究领域内已发布大量与退役电池相关的文献和资讯,汇总行业关键信息,为业内人员提供参考十分有必要。为此,本综述立足行业现状,讨论了退役动力电池不同回收利用方式对环境和经济的影响,同时,分析回收利用现状并归纳研究进展,提出退役动力电池碳排放核算方法,指出回收的必要性和可行性,为建设无废城市和实现“双碳”目标提供借鉴。希望电池回收行业未来能够在国家的宏观调控下,结合高效绿色的回收技术和相关标准规范实现健康有序发展。要点:(1)退役电池回收再生能够有效实现资源循环利用并减少碳排放。(2)不同电池再生方式产生的环境影响和经济效益各异。(3)退役动力电池碳核算是助力“双碳”目标实现的重要方式。

Design and fabrication of self-suspending aluminum-plastic/semiconductor photocatalyst devices for solar energy conversion

The design and synthesis of self-suspending photocatalyst device with easy recyclability is important for practical application.Here,this work utilizes aluminum-plastic package waste as raw material to prepare an aluminum-plastic supported TiO_(2)(AP-TiO_(2))photocatalyst device through 3D printing design and surface deposition method.A series of characterizations were carried out to explore the structure,morphology and performance of the AP-TiO_(2)device.Under UV light illumination,the AP-TiO_(2)-50 efficiently degrade 93.6%tetracycline hydrochloride(THC)after 4 hr,which increases by 8.3%compared with that of TiO_(2)powder suspension system with the same catalyst amount.Based on it,AP-ZnO,AP-CdS,AP-g-C_3N_4and AP-Pt-TiO_(2)are also fabricated,and applied in photocatalytic degradation and hydrogen evolution,which all exhibit higher photoactivities than powder suspension systems.This work provides a new avenue for the fabrication of advanced recyclable photocatalyst device.Moreover,the work offers a novel sight for the high-value utilization of aluminum-plastic package waste,which has positive implications for environmental protection.

Extraordinarily stable and wide-temperature range sodium/potassium-ion batteries based on 1D SnSe2-SePAN composite nanofibers

Developing electrodes with long lifespan and wide-temperature adaptability is crucial important to achieve high-performance sodium/potassium-ion batteries(SIBs/PIBs).Herein,the SnSe2-SePAN composite was fabricated for extraordinarily stable and wide-temperature range SIBs/PIBs through a coupling strategy between controllable electrospinning and selenylation,in which SnSe2 nanoparticles were uniformly encapsulated in the SePAN matrix.The unique structure of SnSe2-SePAN not only relieves drastic volume variation but also guarantees the structural integrity of the composite,endowing SnSe2-SePAN with excellent sodium/potassium storage properties.Consequently,SnSe2-SePAN displays a high sodium storage capacity and excellent feasibility in a wide working temperature range(-15 to 60℃:300 mAh g^(-1)/700 cycles/-15℃;352 mAh g^(-1)/100 cycles/60℃at 0.5 A g^(-1)).At room temperature,it delivers a record-ultralong cycling life of 192 mAh g^(-1)that exceeds 66000 cycles even at 15 A g^(-1).It exhibits extremely superb electrochemical performance in PIBs(157 mAh g^(-1)exceeding 15000 cycles at 5 A g^(-1)).The ex situ XRD and TEM results attest the conversion-alloy mechanism of SnSe2-SePAN.Also,computational calculations verify that SePAN takes an important role in intensifying the electrochemical performance of SnSe2-SePAN electrode.Therefore,this study breaks new ground on solving the polyselenide dissolution issue and improving the wide temperature workable performance of sodium/potassium storage.

Electrospinning Engineering Enables High‑Performance Sodium‑Ion Batteries

As a promising energy storage device,sodium-ion batteries(SIBs)have received continuous attention due to their low-cost and environmental friendliness.However,the sluggish kinetics of Na ion usually makes SIBs hard to realize desirable electrochemical performance when compared to lithium-ion batteries(LIBs).The key to addressing this issue is to build up nanostructured materials which enable fast Na-ion insertion/extraction.One-dimensional(1D)nanocarbons have been considered as both the anode and the matrix to support active materials for SIB electrodes owing to their high electronic conductivity and excellent mechanical property.Because of their large surface areas and short ion/electron difusion path,the synthesized electrodes can show good rate performance and cyclic stability during the charge/discharge processes.Electrospinning is a simple synthetic technology,featuring inexpensiveness,easy operation and scalable production,and has been largely used to fabricate 1D nanostructured composites.In this review,we frst give a simple description of the electrospinning principle and its capability to construct desired nanostructures with diferent compositions.Then,we discuss recent developments of carbon-based hybrids with desired structural and compositional characteristics as the electrodes by electrospinning engineering for SIBs.Finally,we identify future research directions to realize more breakthroughs on electrospun electrodes for SIBs.

N-doped CoAl oxides from hydrotalcites with enhanced oxygen vacancies for excellent low-temperature propane oxidation

A series of nitrogen-doped CoAlO(N-CoAlO)were constructed by a hydrothermal route combined with a controllable NH_(3) treatment strategy.The effects of NH_(3) treatment on the physico-chemical properties and oxidation activities of N-Co AlO catalysts were investigated.In comparison to CoAlO,a smallest content decrease in surface Co^(3+)(serving as active sites)while a largest increased amount of surface Co^(2+)(contributing to oxygen species)are obtained over N-Co AlO/4h among the N-CoAlO catalysts.Meanwhile,a maximum N doping is found over N-CoAlO/4h.As a result,N-CoAlO/4h(under NH_(3) treatment at 400℃ for 4 hr)with rich oxygen vacancies shows optimal catalytic activity,with a T90(the temperature required to reach a 90% conversion of propane)at 266℃.The more oxygen vacancies are caused by the co-operative effects of N doping and suitable reduction of Co^(3+) for NCoAlO/4h,leading to an enhanced oxygen mobility,which in turn promotes C_(3)H_(8) total oxidation activity dominated by Langmuir-Hinshelwood mechanism.Moreover,in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTs)analysis shows that N doping facilities the decomposition of intermediate species(propylene and formate)into CO_(2)over the catalyst surface of N-CoAlO/4h more easily.Our reported design in this work will provide a promising way to develop abundant oxygen vacancies of Co-based catalysts derived from hydrotalcites by a simple NH_(3) treatment.

Insights into the Low-temperature Synthesis of LaCoO3 Derived from Co(CH3COO)2 Via Electrospinning for Catalytic Propane Oxidation

Summary of main observation and conclusion A series of electrospun LaCoO3 perovskites derived from CoX2 (X =CH3COO-,NO3-) were prepared and investigated for total propane oxidation.It is shown that pure rhombohedral perovskite LaCoO3 from Co(CH3COO)2 can be obtained at a relatively low temperature,400 ℃,benefitting from the complexation effect of CH3COO-.On the other hand,CH3COO-can accelerate the complete decomposition of polymer.The low-temperature process can protect LaCoO3 nanoparticles from growing up.