废旧锂离子电池正极材料资源化回收与再生

随着电子设备的普及和电动汽车行业的迅速崛起,作为提供能量来源的锂离子电池发挥着重要的作用。以钴酸锂、磷酸铁锂以及三元正极材料为代表的锂离子电池产销量不断增加;与此同时,为了提供更长的续航时间以及续航稳定性,新型锂离子电池材料的研究工作也在不断推进。在此背景下,锂离子电池正极材料的失效、废弃以及资源化回收再生的过程就显得愈发重要,如何在下游解决报废锂离子电池处理的问题也逐渐提上日程。基于此,本文分别从湿法和火法再生两个角度对废旧锂离子电池正极材料的回收和再生过程进行了介绍,包括回收条件优化的方法、较为新颖的回收再生方法以及再生材料的性能等,并总结了回收再生过程的杂质元素,包括铝、铜等元素对再生材料结构和性能的影响以及工业上常用的回收废旧锂离子电池的方法和环境影响。最后对锂离子电池回收的方法进行总结并进行展望。     

Phosphorene: a Potential 2D Material for Highly Efficient Polysulfide Trapping and Conversion

Effectively trapping lithium polysulfide species and accelerating the reaction conversion kinetics are the main strategies to improve the performance of lithium-sulfur(Li-S) batteries. Since the researchers found in 2014 that two-dimensional(2D) phosphorene nanosheets could be exfoliated from the bulk black phosphorus, numerous researches have been devoted to exploring the phosphorene with unique properties for the application in Li-S batteries. In this review, we summarize the recent theoretical and experimental progress of phosphorene for Li-S batteries. Besides, we also introduce the relationship between the interfacial interaction on phosphorene and the performance enhancement of Li-S batteries. Furthermore, future challenges and remaining opportunities for phosphorene in Li-S batteries are finally discussed.     

Thermo IRIS IntrepidⅡ型电感耦合等离子体发射光谱仪故障快速判断方法

针对Thermo IRIS IntrepidⅡ型电感耦合等离子体发射光谱仪（ICP-OES）在测定含金基体溶液中的杂质元素时,仪器出现灵敏度下降、稳定性变差等现象,通过故障现象分析和排查,给出相应的解决方案,确保仪器恢复到正常使用状态.     

Photoinduced Single‐Electron Transfer as an Enabling Principle in the Radical Borylation of Alkenes with NHC–Borane

A photoinduced SET process enables the direct B?H bond activation of NHC–boranes. In contrast to common hydrogen atom transfer (HAT) strategies, this photoinduced reaction simply takes advantage of the beneficial redox potentials of NHC–boranes, thus obviating the need for extra radical initiators. The resulting NHC–boryl radical was used for the borylation of a wide range of α‐trifluoromethylalkenes and alkenes with diverse electronic and structural features, providing facile access to highly functionalized borylated molecules. Labeling and photoquenching experiments provide insight into the mechanism of this photoinduced SET pathway.     

Effect of ethyl‐bridged diphenylphosphine oxide on flame retardancy and thermal properties of epoxy resin

Three commercialized flame retardants, 1,2‐bis(diphenylphosphinoyl)ethane (EDPO), 6,6‐(1,2‐phenethyl)bis‐6H‐dibenz[c,e][1,2]oxaphosphorin‐6,6‐dioxide (HTP‐6123), and hexa‐phenoxy‐cyclotriphosphazene (HPCTP), were used to prepare the flame retardant diglycidyl ether of bisphenol A (DGEBA) epoxy resin (EP) under the same experimental conditions. The effects of T_g, thermal stability, and water absorption properties of EP caused by the three flame retardants were investigated and compared, together with their flame retardant efficiency. Results showed that the introduction of the three flame retardants improved the flame retardant performance of EP but led to decreases in T_g and decomposition temperature. EDPO showed higher flame retardant efficiency than the other two flame retardants. EP/EDPO showed higher thermal stability, better flame retardant performance, higher T_g value, and lower water absorption than EP/HTP‐6123 and EP/HPCTP. The study discovered that EDPO and HTP‐6123 primarily act through the gas phase flame retardant mechanism, while HPCTP is primarily driven by the condensed phase mechanism.     

饲料中重金属检测技术的研究进展

综述了饲料中重金属的检测方法如光谱分析法(包括原子吸收光谱法、原子荧光光谱法、电感耦合等离子体发射光谱法、X-射线荧光光谱法和激光诱导击穿光谱法)、电感耦合等离子体质谱法、电化学分析法和分光光度法的研究进展,对各类检测方法的优缺点进行了对比与分析,并在此基础上对饲料中重金属检测技术的发展趋势进行了展望。     

不同烟草生物质热解释放致香物质的研究

采用烟叶和烟梗为原料,使用热裂解气相色谱法对烟草的燃烧时间、燃烧温度进行控制,精确模拟实际烟草致香物质释放环境,精确捕获、并半定量物质,从而在实验室模拟、分析、研究烟草燃烧物中致香物质的组成和特点。研究分别考察了两种生物质在500℃、550℃下释放的致香物质组成。结果表明,烟梗、烟叶中元素组成中硫、氮两种元素含量低,而C/H比值两种烟草生物质均较高。两个热解温度下烟叶的热解产物中致香物质的含量均明显高于烟梗。升高热解温度均有利于获得更高相对含量的热解成分。烟叶热解产物中烯烃类物质相对含量比烟梗中多,而烟梗热解产物中酚类物质含量比烟叶中多。提高热解温度有利于酮类致香物质含量产生。     

Flame retardancy and smoke suppression of silicone foams with microcapsulated aluminum hypophosphite and zinc borate

The flame‐retardant microcapsules were successfully fabricated with an aluminum hypophosphite (AHP) core. Fourier transform infrared (FTIR) and X‐ray photoelectron spectroscopy (XPS) were used to verify that AHP was encapsulated in the microcapsules, and thermogravimetry analysis showed that microencapsulated AHP (MAHP) possessed higher thermal stability than that of AHP. Then, a flame‐retardant and smoke suppression system for silicone foams (SiFs) was obtained through a synergistic effect of MAHP and zinc borate (2ZnO·3B₂O₃·3.5H₂O). The mechanical properties, flame retardance, and smoke suppression of SiFs with MAHP and zinc borate were tested using the tensile test, limiting oxygen index (LOI) test, UL‐94 test, and cone calorimeter test. The mechanical properties indicated that the tensile strength and elongation at break of SiFs could evidently improve with the incorporation of MAHP. Compared with pure SiF, SiF8 with 4.5‐wt% MAHP and 1.5‐wt% zinc borate could achieve an LOI value of 30.7 vol% and an UL‐94 V‐0 rating, the time to ignition amplified almost six times, the peak heat release rate and total heat release were 51.10% and 46.00% less than that of pure SiF, respectively, the fire performance index increased nearly 13 times, and the fire growth index value was only 13.18% of pure SiF. Moreover, the partial substitution of zinc borate imparted a substantial improvement in both flame retardancy and smoke suppression. Especially, the peak smoke production rate and total smoke production of SiF8 were merely 38.46% and 38.84% of pure SiF.     

Non‐natural Cofactor and Formate‐Driven Reductive Carboxylation of Pyruvate

A non‐natural cofactor and formate driven system for reductive carboxylation of pyruvate is presented. A formate dehydrogenase (FDH) mutant, FDH*, that favors a non‐natural redox cofactor, nicotinamide cytosine dinucleotide (NCD), for generation of a dedicated reducing equivalent at the expense of formate were acquired. By coupling FDH* and NCD‐dependent malic enzyme (ME*), the successful utilization of formate is demonstrated as both CO₂ source and electron donor for reductive carboxylation of pyruvate with a perfect stoichiometry between formate and malate. When ¹³C‐isotope‐labeled formate was used in in vitro trials, up to 53 % of malate had labeled carbon atom. Upon expression of FDH* and ME* in the model host E. coli, the engineered strain produced more malate in the presence of formate and NCD. This work provides an alternative and atom‐economic strategy for CO₂ fixation where formate is used in lieu of CO₂ and offers dedicated reducing power.