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物 理 化 学 学 报Acta Phys. -Chim. Sin. 2023, 39 (8), 2205012 (1 of 10)Received: May 6, 2022; Revised: May 26, 2022; Accepted: May 27, 2022; Published online: June 9, 2022. *Correspondingauthors.Emails:********************.cn(Y.S.);*******************.cn(L.C.).This project was supported by the National Key Research and Development Program of China (2021YFB3800300) and the National Natural Science Foundation of China (21733012, 22179143).国家重点研究发展项目(2021YFB3800300)和国家自然科学基金(21733012, 22179143)资助© Editorial office of Acta Physico-Chimica Sinica[Article] doi: 10.3866/PKU.WHXB202205012 A Single-Ion Polymer Superionic ConductorGuoyong Xue 1,2, Jing Li 2, Junchao Chen 3, Daiqian Chen 2, Chenji Hu 2,3, Lingfei Tang 1,2, Bowen Chen 1,2, Ruowei Yi 2, Yanbin Shen 1,2,*, Liwei Chen 2,3,*1 School of Nano-Tech and Nano-Bionics, University of Science and Technology of China, Hefei 230026, China.2 i-Lab, CAS Center for Excellence in Nanoscience, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Science,Suzhou 215123, Jiangsu Province, China.3School of Chemistry and Chemical Engineering, Shanghai Jiaotong University, Shanghai 200240, China.Abstract: All-solid-state batteries (ASSBs) have been considered a promising candidate for the next-generation electrochemical energy storage because of their high theoretical energy density and inherent safety. Lithium superionic conductors with high lithium-ion transference number and good processability are imperative for the development of practical ASSBs. However, the lithium superionic conductors currently available are predominantly limited to hard ceramics. Practical lithium superionic conductors employing flexible polymers areyet to be realized. The rigid and brittle nature of inorganic ceramic electrolytes limits their application in high-performance ASSBs. In this study, we demonstrate a novel design of a ternary random copolymer single-ion superionic conductor (SISC) through the radical polymerization of three different organic monomers that uses an anion-trapping borate ester as a crosslinking agent to copolymerize with vinylene carbonate and methyl vinyl sulfone. The proposed SISC contains abundant solvation sites for lithium-ion transport and anion receptors to immobilize the corresponding anions. Furthermore, the copolymerization of the three different monomers results in a low crystallinity and low glass transition temperature, which facilitates superior chain segment motion and results in a small activation energy for lithium-ion transport. The ionic conductivity and lithium-ion transference number of the SISC are 1.29 mS·cm −1 and 0.94 at room temperature, respectively. The SISC exhibits versatile processability and favorable Young’s modulus (3.4 ± 0.4 GPa). The proposed SISC can be integrated into ASSBs through in situ polymerization, which facilitates the formation of suitable electrode/electrolyte contacts. Solid-state symmetric Li||Li cells employing in situ polymerized SISCs show excellent lithium stripping/plating reversibility for more than 1000 h at a current density of 0.25 mA·cm −2. This indicates that the interface between the SISC and lithium metal anode is electrochemically stable. The ASSBs that employ in situ polymerized SISCs coupled with a lithium metal anode and various cathodes, including LiFePO 4, LiCoO 2, and sulfurized polyacrylonitrile (SPAN), exhibit acceptable electrochemical stability, including high rate performance and good cyclability. In particular, the Li||LiFePO 4 ASSBs retained ~ 70% of the discharge capacity when the charge/discharge rate was increased from 1 to 8C . They also demonstrate long-term cycling stability (> 700 cycles at 0.5C rate) at room temperature. A capacity retention of 90% was achieved even at a high rate of 2C after 300 cycles at room temperature. Furthermore, the SISCs have been applied to Li||LiFePO 4 pouch cells and exhibit exceptional flexibility and safety. This work provides a novel design principle for the fabrication of polymer-based superionic conductors and is valuable for the development of practical ambient-temperature ASSBs.Key Words: All-solid-state lithium metal battery; Solid polymer electrolyte; Superionic conductor;Single-ion conductor; In situ polymerization; Rate performance单离子聚合物快离子导体薛国勇1,2，李静2，陈俊超3，陈代前2，胡晨吉2,3，唐凌飞1,2，陈博文1,2，易若玮2，沈炎宾1,2,*，陈立桅2,3,*1中国科学技术大学纳米技术与纳米仿生学院，合肥 2300262中国科学院苏州纳米技术与纳米仿生研究所，创新实验室卓越纳米科学中心，江苏苏州 2151233上海交通大学化学化工学院，上海 200240摘要：具有高锂离子迁移数和良好可加工性能的锂快离子导体对于全固态电池的发展非常重要。
金华2024年统编版小学三年级英语第五单元暑期作业(含答案)考试时间：80分钟（总分:140）A卷一、综合题(共计100题共100分)1. 选择题：What do we celebrate on December 25th?A. HalloweenB. ThanksgivingC. ChristmasD. New Year答案: C2. 填空题：I have a collection of ______ (邮票) from different countries. Each stamp tells a ______ (故事).3. 填空题：The peacock's feathers are stunning during ______ (求偶).4. ts bloom only once a ______. (某些植物每年只开一次花。
) 填空题：Some pla5. 选择题：What is the name of the fairy tale character who leaves a glass slipper?A. Snow WhiteB. CinderellaC. RapunzelD. Little Red Riding Hood6. 听力题：Chemical weathering involves the breakdown of rocks by ______ processes.7. 听力题：The corn is ___ (growing) tall.The children are _____ with their toys. (happy)9. 填空题：My grandmother is a __________ (历史学家).10. 听力题：The chemical formula for oleyl alcohol is ______.11. 选择题：How many days are in a week?A. FiveB. SixC. SevenD. Eight12. 填空题：The ________ was a key event in the history of civil rights in the United States.13. 选择题：What is the boiling point of water?A. 0°CB. 50°CC. 100°CD. 200°C答案:C14. 选择题：What is the name of the famous landmark in Egypt?A. Great WallB. ColosseumC. Eiffel TowerD. Pyramids答案: D15. 填空题：The __________ (历史的传承) carries forward wisdom.16. 听力题：The chemical symbol for hafnium is ______.17. 听力题：A _______ is a solution that contains less solute than it can hold.18. 听力题：Many plants produce __________ to attract pollinators.What is the capital of Madagascar?A. AntananarivoB. MahajangaC. ToamasinaD. Antsiranana答案:A20. 听力题：The Earth's surface is home to a wide variety of ______.21. 填空题：A __________ (园艺师) takes care of all the plants.22. 填空题：I want to _______ a superhero when I grow up.23. 选择题：What is 3 + 5?A. 7B. 8C. 9D. 1024. 听力题：She is going to the ___. (store)25. 填空题：Vikings are known for their _____ and exploration.26. 选择题：How many colors are in a standard color wheel?A. 6B. 8C. 10D. 12答案: D27. 听力题：The _____ (butter) melts on the bread.28. 填空题：A bison can weigh up to ______ (一吨) or more.29. 选择题：What is the name of the animal that can live both in water and on land?A. FishB. FrogC. LizardD. Turtle30. 填空题：A _____ (小马) often enjoys being pampered.31. 听力题：A _______ is a solution that contains more solute than it normally would at a given temperature.32. 选择题：What is the name of the famous mountain in Africa?A. KilimanjaroB. Mount KenyaC. Atlas MountainsD. Rwenzori Mountains33. 填空题：We play ______ (游戏) during recess.34. 填空题：Understanding how to propagate plants can lead to a more abundant ______. (了解如何繁殖植物可以导致更加丰盛的园艺。
实用电镀液配方与制备200例English Answer：Introduction.Electroplating is an essential process in various industries, including electronics, automotive, and jewelry manufacturing. The success of electroplating depends on the use of suitable electroplating solutions or electrolytes. These solutions contain metal ions, electrolytes, and other additives that facilitate the deposition of a metal coating on the surface of a substrate. In this article, we present 200 practical electroplating solution formulations and provide detailed instructions for their preparation.Electroplating Solution Formulations.The choice of electroplating solution formulation depends on the desired coating material, substrate, and application. Here are 200 common electroplating solutionformulations for different metals and substrates: 1. Acid Copper Electroplating Solution.Copper sulfate: 200 g/L.Sulfuric acid: 50 mL/L.2. Alkaline Copper Electroplating Solution. Copper cyanide: 30 g/L.Sodium cyanide: 50 g/L.Sodium hydroxide: 50 g/L.3. Gold Electroplating Solution.Gold chloride: 1 g/L.Potassium cyanide: 5 g/L.Potassium dihydrogen phosphate: 15 g/L.4. Nickel Electroplating Solution.Nickel sulfate: 240 g/L.Nickel chloride: 50 g/L.Boric acid: 30 g/L.5. Silver Electroplating Solution.Silver cyanide: 30 g/L.Potassium cyanide: 60 g/L.Sodium thiosulfate: 10 g/L.6. Zinc Electroplating Solution.Zinc sulfate: 300 g/L.Zinc chloride: 10 g/L.Boric acid: 30 g/L.Preparation of Electroplating Solutions.The preparation of electroplating solutions involves several steps:1. Dissolving the Metal Salt: Dissolve the appropriate metal salt (e.g., copper sulfate, gold chloride) in a portion of the deionized water.2. Adding Electrolytes: Add electrolytes (e.g., sulfuric acid, cyanide) to enhance the conductivity of the solution.3. Adjusting the pH: Adjust the pH of the solution using acids or bases to the desired range.4. Filtering the Solution: Filter the solution to remove any impurities or particulate matter.5. Additives: Add specific additives (e.g., brighteners, levelers) to modify the properties of the deposited coating.Safety Precautions.Electroplating solutions often contain hazardous chemicals. It is crucial to follow safety precautions when handling and preparing these solutions:Wear proper personal protective equipment (PPE), including gloves, goggles, and a lab coat.Work in a well-ventilated area or use a fume hood.Dispose of spent solutions and rinse water accordingto environmental regulations.Conclusion.Electroplating solutions play a vital role in the successful deposition of metal coatings. This articleprovides 200 practical electroplating solution formulations and detailed instructions for their preparation. By carefully following these formulations and safety guidelines, you can achieve high-quality electroplated coatings for various applications.Chinese Answer：前言。
电催化剂英语Electrochemical Catalysts: Revolutionizing Energy Conversion and StorageElectrochemical catalysts have emerged as a critical component in the global pursuit of sustainable energy solutions. These remarkable materials have the ability to accelerate chemical reactions, enabling more efficient and cost-effective energy conversion and storage technologies. From fuel cells to metal-air batteries, electrochemical catalysts have the potential to transform the way we harness and utilize energy, paving the way for a cleaner and more sustainable future.At the heart of electrochemical catalysis lies the intricate interplay between the catalyst's structure, composition, and the electrochemical reactions it facilitates. Catalysts can be designed to target specific reactions, optimizing their performance and selectivity. This tailored approach allows for the development of highly efficient systems that can overcome the limitations of traditional energy technologies.One of the primary applications of electrochemical catalysts is in fuelcells. Fuel cells are electrochemical devices that convert the chemical energy of fuels, such as hydrogen or methanol, directly into electrical energy. The efficiency of fuel cells is largely dependent on the performance of the catalysts used in the electrochemical reactions. Platinum-based catalysts have been widely used in fuel cell technology, but their high cost and limited availability have driven the search for alternative, more cost-effective catalysts.Researchers have explored a wide range of non-precious metal catalysts, such as transition metal oxides, nitrides, and sulfides, as well as carbon-based materials, to address the cost and scarcity issues associated with platinum. These alternative catalysts have shown promising performance, often matching or even exceeding the activity and durability of their platinum-based counterparts. The development of these cost-effective and earth-abundant catalysts has the potential to significantly improve the commercialization and widespread adoption of fuel cell technology.Another crucial application of electrochemical catalysts is in metal-air batteries, which have gained attention due to their high energy density and potential for low-cost energy storage. In these batteries, the electrochemical reactions at the air cathode are catalyzed by specific materials, enabling efficient oxygen reduction and oxygen evolution. The performance of these catalysts directly impacts the battery's energy efficiency, cycle life, and overall viability as anenergy storage solution.Researchers have explored a variety of catalyst materials for metal-air batteries, including transition metal oxides, perovskites, and carbon-based materials. These catalysts have shown improved activity, stability, and selectivity, addressing the challenges associated with traditional metal-air battery technologies. The development of advanced electrochemical catalysts has the potential to unlock the full potential of metal-air batteries, making them a more attractive option for large-scale energy storage applications.Beyond fuel cells and metal-air batteries, electrochemical catalysts play a crucial role in other energy conversion and storage technologies, such as water electrolysis and metal-ion batteries. In water electrolysis, catalysts are used to facilitate the splitting of water molecules into hydrogen and oxygen, enabling the production of clean hydrogen fuel. Similarly, in metal-ion batteries, electrochemical catalysts can enhance the efficiency of the redox reactions, leading to improved energy density and cycle life.The versatility of electrochemical catalysts extends beyond energy applications. These materials also find use in environmental remediation, such as the electrochemical treatment of wastewater and the removal of pollutants. Catalysts can be designed to selectively target and degrade various contaminants, making themvaluable tools in the quest for sustainable and eco-friendly solutions.The development of advanced electrochemical catalysts is an ongoing and dynamic field of research, with scientists and engineers continuously exploring new materials, structures, and synthesis methods to enhance their performance and cost-effectiveness. Computational modeling and machine learning techniques have played a crucial role in accelerating the discovery and optimization of novel catalyst materials, enabling rapid progress in this field.As the global demand for clean and efficient energy solutions continues to grow, the importance of electrochemical catalysts cannot be overstated. These remarkable materials hold the key to unlocking the full potential of energy conversion and storage technologies, paving the way for a more sustainable and environmentally-conscious future. Through continued research and innovation, electrochemical catalysts will undoubtedly play a pivotal role in shaping the energy landscape of tomorrow.。
原子与分子物理学报JOURNAL OF ATOMIC AND MOLECULAR PHYSICS第37卷第6期2020年12月Vol. 37 No. 6Dec. 2020doi : 10.19855/j.l000-0364.2020.066003用于全固态锂电池的有机-无机复合电解质金英敏，李栋，贾政刚，熊岳平(哈尔滨工业大学化工与化学学院，哈尔滨市150001)摘要：固态电解质被认为是解决传统液态锂金属电池安全隐患和循环性能的关键材料，但仍然存在离子 电导率低，界面兼容性差等问题.设计兼顾力学性能、离子电导率和电化学窗口的有机-无机复合型固态电解质材料是发展全固态锂电池的明智选择.近年来,基于无机填料与聚合物电解质的有机-无机复合电解质备受关注.设计与优化复合电解质结构对提高复合电解质综合性能具有重要意义.本文详细梳理了有机-无机复合固态电解质在全固态锂电池中展现明多方面优势，从满足不同性能需求的复合电解质结构设计角度出发，综述了有机-无机复合电解质在锂离子传导、锂枝晶的抑制、界面稳定性和相容性等方面的研究进展，并对有机-无机复合电解质明未来发展趋势和方方进行了展望.关键词：全固态锂电池；固态电解质；复合型固态电解质；结构设计中图分类号：O65 文献标识码：A 文章编号：1000-0364(2020)06-0958 06Organic - inorganic composite electrolytes for all - solid - state lithium batteriesJIC Ying-Min # LI Dong, JIA Zheng-Gang, XIONG Yue-0ing(School of Chemistry and Chemical engineering , Harbin Institute of Technology , Harbin 150001 , China )Abstrach : Solid electrolytes ary consitered te be a promising candidaie te replace traditional liquid electrolytes due te their enhanced safety and cycling perfoanance. UnfoOunately , the low ionic conductivity of solid electro lytes and the pooa interfacial contact at electrolyte/electrode interface limii theia application in Li bateaet. Thus , developing novd electrolyee systems based on ceramit fnieo - incoa^orated polymeo electrolytes w WU im proved mechanical strength , ionie conductivim and wide electrochemical window is the ultimate solution for aH -solid - state cithium bateries. Recently , composite soliO cectrolytes containing ceramie and polymer elee-holytes have drawn a loe of attention. Designing and optimizing tee structure of composite solid electrolytes is ofgoct importance te boosi tee overali performance. The multipie adventages of oroanie - inoroanie composite eleo-trolytes assembled in H - solid - state lithium bateries ho discussed in the text. Resecrch prooress on structurai design of composite solid electrolytes from the perspective of meeting diferent performance demands consinering Li-ion eoanspooem>thanism, Lid>ndoie suppo sion and ineooat>seabieietao summaoii>d.Th>oueuo>d>e>e-opment trend and direction of oraanio - inoraanio composite electrolytes ga also mentioned.Key words : All - solid - state lithium biteries ； Solid electrolytes ; Composite solid electrolytes ; Structural de sign收稿日期：2020-07-16基金项目：特种化学电源国家重点实验室开放课题"SKL - ACP -C-14)作者简介：金英敏(1996—)#女#朝鲜族#黑龙江省齐齐哈尔市人#博士生#从事全固态锂电池的研究.E-mail : jyinjinyingminKlG!. com通讯作者：熊岳平(1963—)#男#汉族#吉林省九台市人#教授#博导#从事固体氧化物燃料电池和全固态锂电池的研究.E-mait : ypxiong@ hit. edu. cn第6期金英敏，等：用于全固态锂电池的有机-无机复合电解质9591引言锂离子电池自20世纪90年代问世以来，由于其具有能量密度高、输出功率大、电压高、自放电小、工作温度范围宽、无记忆效应和环境友好等优点[1"3],现已成为最重要的能源存储器件之一，被广泛应用于电动车、轨道交通、大规模储能和航空航天等领域[4,5]-然而，传统液态锂离子电池采用液态电解液，不仅存在易泄漏、易挥发、易燃烧等安全隐患[6],而且在充放电过程中容易和电极发生副反应、高电压下会分解产气,导致电池容量出现不可逆衰减-除此之外，使用石墨负极的液态锂离子电池的能量密度已经接近其上限[7]，而液态体系无法使用高能量密度的金属锂作为负极材料，这是因为锂电极表面不均匀的锂沉积会导致锂枝晶的生长，最终刺穿隔膜造成电池内部短路、热失控甚至起火爆炸叫固态电解质的使用，不仅避免了液态有机电解液带来的一系列安全隐患，还可逆避免锂枝晶刺穿隔膜的问题，提高了电池的安全性-除此之外，固态电解质宽的电化学窗口允许锂金属负极和高电压正极材料的同时使用，是提升锂离子电池能量密度的有效途径[9，10]-全固态锂金属电池兼具高安全性和高能量密度的优点，被认为是最具发展潜力的下一代锂电池技术，得到了广泛关注与研究(固态电解质作为全固态锂电池的核心组分，是制备高能量密度、高循环稳定性和高安全性能全固态锂电池的关键材料.因此开发出性能优异的固态电解质已经成为研究者们的关注重点•2固态电解质概述为了实现固态锂金属电池的高安全性和高能量密度，固态电解质除了具备优异的力学性能和热稳定性，还应满足来下要求：室温锂离子电导率高，电化学窗口宽，对锂金属电化学稳定性高，与电极界面阻抗低，加工性能优异，易于大规模生产等.通常，固态电解质可分为无机固态电解质和聚合物固态电解质两大类.其中，无机固态电解质作为单离子导体，在室温具有较高的离子电导率(10"~10x4S・cm")和较高的锂离子迁移数(T+接近1)[11]-氧化物型和硫化物型固态电解质是无机固态电解质的两类典型代表，一些硫化物如23PS4、Li i0GeP*S i2等具有接近甚至高于液态电解质的离子电导率，但在空气中不稳定,易释放H2S.12，1!/-尽管氧化物固体电解质化学稳定性较高，但也存在其他因素限制其应用-例如, NASICON型电解质Li i+n A'Ti*」PO4)3(LATP)、Li i+n A'Ge*」PO4)3(LAGP)和钙钛矿型电解质(Li0.33La0.557Ti O3,LLTO)和锂电极之间的化学稳定性差，TO_容易被金属锂还原成TO+[14]-Garnet型电解作(LO La3Z-2O12,LLZO)虽然和锂电极相对稳定，但对空气中的水分和CO敏感，表面易形成loco3和的日层，阻碍离子传输[15]-刚性的无机固态电解质虽然可逆物理地抑制锂枝晶的生长，但正是由于其本身的刚性，与电极接触时界面相容性差，产生较大的电极/电解质固固接触阻抗.除此之外，制备工艺复杂使无机固态电解质难来大规模生产[16]-往往需要采用在电解质或电极表面进行修饰口、弓引界面层1R，19/、采用合金电极[20]等手段来改善界面接触和界面离子传输.与无机固态电解质相比，聚合物固态电解质对电极的浸润性更好，可与电极紧密接触并保证界面连续的离子传输通道；具有高度的可塑性和柔韧性，机械加工性能好，可塑根据要求制作成所需形状，适合批量化制备和大规模生产[21]-聚合物固态电解质通常是由具有极性基团如—O-,=O,—N-,—S-,C=O,C:N等的极性高分子和锂盐络合后通过溶液浇筑法制得，具有较好的柔性和加工性能、良好的力学性能和成膜性，且容易与锂金属形成稳定的界面,被为为由要一锂能量在储器件于重有潜力的解质质之一H-在聚合物电解质中，聚环氧乙烷(Polyethylene oxide,PEO)是研究最早的—类体系.1979年，Armand等成功制备了基于PEO聚合物电解质的全固态聚合物锂离子电池-PEO基聚合物电解质的导电过程主要是由锂盐如双三氟甲烷磺酰亚胺锂(LiTFSI)、高氯酸锂(LOIO4)等解离产生的锂离子与PEO链上的一0—持续地发生络合、解络合的过程，是通过PEO无定型相中的链段运动来实现LO的迁移[25,26]-因此，自由移动的LO数量和PEO链段的运动能力决定了PEO基聚合物电解质的离子电导率.锂盐的加界可塑抑制PEO的结晶，提高无定型相的比例，改善锂离子的传输能力[27]-但PEO在室温下结晶度很高，限制了离子传导，只有升高温度会增加无定型相的比例，离子电导率才会提高-为了提升PEO基聚合物电解质的离子电导率，许多方法如在聚合物基体中引入增塑剂叫提高锂盐含960原子与分子物理学报第37卷量［29刖等已被广泛研究，通过减少PEO基体结晶区的比例，加快链段运动，促进锂盐的解离，从而提高离子电导率.尽管这些手段可以提高离子电导率，但同时电解质的机械强度与稳定性也会在一定程度上有所降低.31，32/.另外，PEO固态聚合物电解质电化学窗口相对较窄"V4V).33/，难以匹配高电压正极材料，对固态电池能量密度的提升相对有限；另外PEO基固态锂电池需要在相对较高温度"60〜80°C)下运行，增加了运行成本.除PEO基聚合物体系外，聚偏氟乙烯"Polyvinylidene fluoride，PVDF).33\聚偏氟乙烯-六氟丙烯(Polyvinylidene fluoride-co-hexafluoropropylene，PVDF_HFP)［34］、聚丙烯腈Polyacrylonitrile，PAN)】⑸等也是重要的聚合物电解质体系. PVDF链段上含有强极性基团一CH*%CF*―，氟原子较强的电负性有利于促进锂盐解离，提升PVDF基体中锂离子的浓度.36/.PAN分子中的氮原子可提供孤对电子，与锂离子发生络合作用.由于氮原子的电负性比氧原子弱，与PEO基体相比，PAN基体与锂离子间的相互作用更弱，因此PAN基体的锂离子迁移数会相对较高.37/.除此之外，PAN基固态电解质具有较高的抗氧化能力，可以匹配高压正极材料，但由于PAN链段上的强极性基团一CN与锂负极相容性较差，导致该体系电解质与锂负极接触时界面处会产生严重的钝化现象.38L更重要的一点，几乎所有的聚合物电解质都存在室温离子电导率相对较低(10一8〜io-5s •cm-1).39/、锂离子迁移数较低仏+V0.5).27/的问题，限制了其应用可行性.由此可见，无论是无机固态电解质还是聚合物固态电解质，现有的单一固态电解质体系难以满足全固态锂金属电池的性能要求•3有机-无机复合固态电解质概述为了兼顾无机固态电解质的高离子电导率以及固态聚合物电解质的柔韧性，通过将无机填料加入聚合物电解质中，发展有机-无机复合型固态电解质成为固态锂金属电池的关键突破口.无机填料因其较高的表面积，可可增强与聚合物基质的接触，缩短锂离子扩散途径.无机填料不仅可可降低聚合物的结晶度，根据路易斯酸碱理论,填料的酸性表面还可可吸附锂盐解离的阴离子,促进锂盐的解离，增加可自由移动的锂离子数量.40/(填料表面作为聚合物链段与锂盐阴离子的交联位点，可形成锂离子传输通道.与纯聚合物固态电解质相比，复合固态电解质具有更低的熔融温度(4m)和玻璃化转变温度"T)40/，更高的离子电导率和力学性能，以及与锂负极更好的兼容性.根据填充物对复合电解质电导率的贡献,可可将它们分为没有参与到导电过程的惰性填充物如SiO*〔41/、TO*.42/、AOO3.43/等，和参与锂离子的传输的活性填料如LLZO.44，45/、LATP:46/、LAGP〔47/、LLTO:48,49/等.活性填料除了可可起到和惰性填料一样的作用之外，还可可直接提供锂离子，不仅能提高自由LO的浓度，还可增强LO 在填料表面的传输能力.50,51/.另外，无机填料在电解质中还可以吸附痕量的水及其它微量杂质,使得复合电解质在电化学环境中更稳定，拓宽电解质的电化学窗口.利用无机材料良好的机械强度和抗穿刺性能与聚合物材料良好的界面相容性和界面稳定性形成的复合电解质，也可可有效地抑制电池运行过程中锂枝晶的生长，提高电池的循环稳定性和库伦效率.例如，Fu等.22/将3D结构的LO.4Lc3Zo2AO.2O12(LLZO)纳米纤维与PEO 基体复合，LLZO纳米纤维的引入不仅延长了LO 的连续传输路径，而且加固了聚合物电解质内部结构的机械强度(图1)•该复合电解质薄膜的离子传导性能有了明显提高，室温离子电导率可达2.5X10"5S•cm一1.图13D LLZO/PEO复合固态电解质结构示意图.22/Fig.1Schematic of the hybrid3D LLZO/PEO solid-state composite electrolyte(Reprinted with permission from.22/.Copyrighi(2016)NationalAcademy of Sciences).有机-无机复合固体电解质，结合了无机固体电解质和聚合物固体电解质的优势，兼具无机物的高强度、高稳定性和聚合物的轻质、柔性.此外，复合界面处的有机-无机相互作用可进一步提升聚合物复合固体电解质的离子电导率.近第6期金英敏，等：用于全固态锂电池的有机-无机复合电解质961年来柔性电子设备发展迅速，可穿戴设备、柔性显示屏等柔性电子器件层出不穷，柔性复合电解质的设计使得薄膜化、微型化、柔性可弯折的锂电池也将成为可能.基于此，本文综述了用于全固态锂电池的有机-无机复合固态电解质，重点论述了复合电解质在锂离子传导、锂枝晶的抑制、界面相容性和稳定性等方面的研究进展，展望了未来高性能固态电解质的研究重点和发展方向•3.1锂离子传导关于有机-无机复合电解质的锂离子导电机理，主要有以下三种观点：⑴有机相导电，(2)无机相导电，(3)有机-无机界面导电.锂盐在聚合物基体中解离为锂离子与阴离子，锂盐与聚合物链段上的极性基团相互作用，锂离子通过在各极性基团间的跳跃实现电荷传输.在有机相中，锂离子主要依赖非结晶区域内聚合物的链段运动实现迁移，这样的迁移方式活化能相对较高、离子电导率相对较低.无机相的离子传导通过锂离子导体型活性填料内部的离子扩散实现，这样的迁移方式具有相对较低的活化能、较快的离子传输速率.关于有机-无机复合界面处的离子传导，首先界面处的无机相表面可穿通过抑制聚合物链段的重排，增加聚合物中无定形态的比例，在界面处形成高离子传导性的非晶区域；其次，无机相表面通过路易斯酸碱作用可穿固定锂盐中的阴离子，促进锂盐解离、提升界面处可自由移动锂离子的数量•随着渗流理论印在有机-无机复合电解质中的应用，已有大量研究表明聚合物相与无机相复合界面处可能存在锂离子快速传输通道化有机-无机复合电解质，通常采用在聚合物基体中分散无机颗粒填料的方式来合成•根据渗流理论，随着填料比例的增加，离子电导率会先上升后下降［53］，当填料含量过高时，颗粒的团聚会阻碍锂离子的传输•若不能保证无机填料的均匀分散以及合适的添加量，则会造成无机填料的团聚、填料与聚合物基体相互作用的削弱，减少聚合物无定形态的比例.2等人［54］探究了(Li6.4La3Zr1.4Ta o.6O12，LLZTO)的颗粒尺寸对LLZ-TO/PEO复合电解质离子电导率的影响.结果表明，与微米级LLZTO相比，具有40nm尺寸的LLZTO和PEO复合形成的电解质其离子电导率高出前者两个数量级•这是因为小颗粒的LLZTO具有更大的比表面积，从而与PEO可形成更多的界面，利于离子传输.聚合物复合固体电解质中的离子传导过程，是一个涉及多相介质和异质界面的复杂过程.需要掌握多相介质和异质界面处的微观结构、锂离子分布以及锂离子传输路径等信息，才能清楚掌握复合固体电解质中的离子传导机制•固态核磁共振"Solid-State Nuclear Magnetic Resonance，SS-NMR)技术是探测离子局部结构和动力学的有效手段，通过分辨$Li和"L同位素在反应前后的含量变化等信息，来研究聚合物复合固体电解质中的离子传导机制•Hu等人［39］下6Li和"Li分别作为复合固体电解质的外源锂和内源锂，通过比较充放电循环前后6Li和"Li的SS -NMR图谱(图2(a))，揭示了Li_在LLZO/PEO (LiTFSI)复合电解质内部的传输轨迹(图2(Z)).对于LLZO(5wt%)-PEO(LiTFSI)电解质，循环后LiTFSI的6Li峰强度增加了23.3%，并且LT 和晶态PEO相互作用的共振峰"0.3ppm)向低强度偏移，说明此时LT的传输路径为PEO基质中解离的LiTFSI，LLZO(5wt%)的加入使得PEO和LT之间相互作用减弱，增加了自由锂离子数量.当LLZO含量增至20w-%时，循环后分解的LLZO和LiTFSI的6Li峰强度分别增加了10.6和21.2%，说明此时锂的迁移路径为分散在PEO中的锂盐(包括LiTFSI和分解的LLZO颗粒).此时的LLZO含量过低，在聚合物基质中呈现分散分布，无法形成有效的连续渗流结构.对于LLZO (50wt%)-PEO(LiTFSI)，循环后LLZO的6Li峰(2.3ppm)强度增加了27.2%，说明此时绝大多数的LT通过由LLZO形成的渗流网络迁移，只有小部分通过PEO中解离的锂盐迁移.在此基础上加入增塑剂四乙二醇二甲醚TEGDME)时，体相LLZO的6Li峰强度仅增加了7.0%，而分解的LLZO和LiTFSI的6Li共振峰分别增强了14.8和14.0%，说明此时锂离子的主要传输路径变为PEO -TEGDME基质中解离的锂盐•该研究还指出，当体系采用LiCKO作为锂盐时，离子传输会有所不同［55］.这是因为TFSI-比CKV具有更大的体积, LiTFSI在PEO中的解离度更高，可可释放出更多的自由锂离子，具有更高的锂离子电导率［56］.Chan等人［57］制备了含有5wt%LLZO纳米线的PAN(LiT104)-LLZO复合电解质"composite polymer electroly-e，CPE)，在复合电解质的高分辨6Li NMR谱中并没有LLZO相的6Li共振峰，可能是因为LLZO较低的含量.除分散在PAN基质中的LiTFSI峰(0.9ppm)之外，也检测到了聚合物/962原子与分子物理学报第37卷⑻Pristine«Li t J Ureplacement(b)PEO(LiTFSI)LLZO•43210-1e Li shift&ppmeons tau-r f目-J」pasodujco占・-1用-J1IpssodLuooacI3*43210-1◎Li shift5!ppmDecomposedInterfaceDecomposedLLZOLLZO(5wt%)-PEO(LiTFSI)•9i•.«•■•:¥*H•LLZO(20wt%)-PEO(LiTFSI)TEGDME*LLZO(50wt%)•LLZO(50wt開卜PEOPEO(LiTFSI)(LiTFSI)(50wt%HEGDME 图2(a)LLZO-PEO(LiTFSI)复合电解质循环前后的6Li NMR图谱，(b)LLZO-PEO( LiTFSI)复合电解质的锂离子传输路径示意图.39/•Fig.2(a)$Li NMR compaWson of pristine and cycleH LLZO-PEO(2辻3=【)composite electrolytes,(h) Schematic of Lt-ion pathways within LLZO-PEO( LiTFSI)composite electrolyteo( Reprinted withpermission from.39/•Copyright(2018)Americon Chemical Society)•陶瓷界面处的LiTFSI共振峰(0b85ppm),二者所占比例分别为62.6和37.4%,这说明有37.4%的PAN已被LLZO修饰(图3(b)).为了探究复合电解质中的锂离子传输路径，对6Li/CPE/6Li电池进行了充放电循环•6Li NMR谱中分散在PAN基质中的LiTFSI共振峰在循环前后几部保持不变,而聚合物/陶瓷界面处的LiTFSI共振峰强度显著增加(图3(c)).这说明LLZO纳米线对PAN聚合物基体具有显著影响，在低含量LLZO的PAN(LTCO q)-LLZO复合电解质中，锂离子更倾向于在修饰后的PAN/CLZO界面进行传输，此时LLZO的含量不足以形成渗流网络使锂离子的迁移只经过LLZO相(图3(a))•在PEO基聚合物电解质中，无机填料的加入可以作为增塑剂来降低聚合物的结晶度，提高锂离子传导能力.而与PEO不同的是，在PAN基聚合物电解质中，陶瓷填料的加入不会显著改变PAN的结晶度•无论是在不含有LLZO还是含有5wt%LLZO纳米线的复合电解质中，PAN的存在形式都是无定型相.这进一步验证了LLZO是通过增强Li_和CIO q-之间的解离来提升电解质中的自由LT含量，从而提高锂离子电导率•该工作同时指出，与添加Al O3的聚合物电解质相比，LLZO由于具有更高的介电常数(40〜60”58/和能与阴离子产生更强相互作用力的路易斯基表面结构.59/，更能促进锂盐的解离，释放出更多的锂离子.在聚合物基体中加入的活性填料可以显著提升复合电解质的离子电导率，不仅是因为活性填图3(a)复合电解质内部锂离子传输路径示意图，(b)PAN(LiClO4)-LLZO复合电解质、PAN(LiC104)电解质和LLZO纳米线的6Li NMR图谱，(O循环前后PAN(LCIO q)-LLZO复合电解质的6Li NMR图谱.57/•Fig.3(a)Schematic showing possible Li+transportpathways in the CPE，(b)6Li NMR spectra ofthe CPE sample containing5wt%undopedLLZO NWs，a blank samp'with only PAN andLiC104，and undoped LLZO NW powder，(c)6Li NMR spectra comparison between the as-made(pristine)and cycled CPEs containing5wt%undoped LLZO NWs(Reprinted with permission from.57/.Copyright(2017)AmericanChemical Society).料本身即为锂离子导体，更是因为在聚合物/陶瓷界面形成了更多的锂离子传输路径.一般情况下,将无机相分散到聚合物基体中，由于高离子电导率的无机相被聚合物基体所分散，使得锂离子传输通道受限于低离子电导率的聚合物相.当填料第6期金英敏，等：用于全固态锂电池的有机-无机复合电解质963达到一定浓度上限时，复合电解质的离子电导率会有一定程度的下降，这是因为填料的团聚破坏了渗流网络.不仅是无机活性填料在聚合物基体中的加入量会显著影响复合固态聚合物电解质的离子传导性能，无机填料的几何结构也会在很大程度上产生影响.因此，在聚合物复合固体电解质中构筑相互连通的无机相结构，提供连续的离子传输路径，充分利用无机活性填料带来的优势，有助于提升其离子电导率.复合电解质的离子电导率与无机填料在聚合物基质中形成的渗流结构密切相关，而渗流结构主要取决于无机填料结构(纳米颗粒，纳米纤维，3D网状结构等).Yu等人®］创新采用3D纳米结构的水凝胶前驱体制备了3D Li0_3P La°.55TO(LLTO)骨架.将PEO和LiTFSI浇筑进LLTO骨架，得到LLTO/PEO(LiTF-SI)复合电解质.聚合物、水、LLTO的相分离促使了连续的3D渗流结构的形成.为了更好的解释LLTO填料结构对内部锂离子传输带来的影响，对不同结构(纳米颗粒和3D骨架结构)与不同含量的LLTO填料进行了电导率规律探究.结果表明，当LLTO纳米颗粒填料的体积分数较低时,电导率变化规律遵循渗流模型.超过2.7vol%时，曲线开始偏离.这是因为纳米颗粒的团聚造成渗流程度随着界面相体积的减少而降低•不连续的锂离子传输路径导致了较低的离子电导率•然而，基于水凝胶结构的3D LLTO骨架形成的复合电解质即使在较高的体积含量时(9.8-18.7 vol%)，仍然具有较高的离子电导率并且遵循渗流模型理论(图4(b)).这是因为三维连续的LL-T0结构抑制了填料的团聚，保证了界面相的连续，提高了渗流程度，从而得到较高的离子电导率.含有3D LLTO结构的复合电解质室温具有8-8x IO'5S-cm'1的电导率，而采用SiO*惰性填料和LLTO纳米颗粒填料的复合电解质的电导率分别仅有9.5x10「6S-cm"和1.9x10_5S -cm'1(图4(a)).根据路易斯酸碱理论，无机填料由于比PEO具有更高的介电常数，可作为阴离子吸附剂，增强锂盐的解离能力.因为LLTO(' >20)的介电常数高于SO*('=4)，所以与惰性填料SiO*相比，LLTO的添加在复合电解质电导率提升方面可作起到更有效的作用•除了有机-无机界面相的增加可作提升电导率之外，LLTO 表面的空位也可作为锂离子跃迁的路径，进一步促进了离子传输，而这是惰性填料所不具备的.除此之外，3D结构的LLTO活性填料比颗粒结构的LLTO具有更显著的提升电导率的作用，进定步验证了该结构在离子传导方面带来的优势(图4 (c,d)).Gu。
