全固态锂离子电池用PEO基聚合物电解质的研究进展

锂离子电池作为重要的能量储存元件在消费类电子产品、电动汽车和可再生能源存储等领域具有广泛的应用。传统液态电解质锂离子电池受到能量密度低、安全性差等诸多缺陷的限制,采用固态电解质替代液态电解质制备新型固态锂离子电池目前备受关注。PEO基固态聚合物电解质由于其设计简单、易于制造、使用安全等优点已被认为是替代传统液体电解质的首选。介绍了当前PEO基聚合物电解质的主要研究种类、特点和性能;阐述了锂离子在PEO基聚合物电解质中的导电机制;分析了与PEO络合的锂盐种类对聚合物电解质的电导率的影响规律;在此基础上提出了几种改善PEO基聚合物电解质性能的措施和方法。     

锂离子电池电解液产业分析

一、锂离子电池电解质技术概况锂离子电池制造所需的正极材料、负极材料、隔膜和电解质材料被称为锂离子电池4大关键材料,其中,锂离子电池电解质按其存在形态大致可以分为液态电解质、凝胶态电解质和固态电解质3种。从1991年全球第一只商业化锂离子电池诞生至今,锂离子电池电解质材料呈现出从液态到固态逐步发展的过程。现阶段,在电解质市场居统治地位的是液态电解质,一     

锂离子电池玻璃及玻璃陶瓷固体电解质材料研究

综述了固态锂离子电池用的玻璃及玻璃陶瓷固体电解质材料研究现状, 包括氧化物、硫化物及氧硫化物玻璃固体电解质材料和氧化物、硫化物玻璃陶瓷固体电解质材料的电化学性能, 并讨论了材料的结构和形貌对其电化学性能的影响, 以及全固态电池的性能, 最后对全固态锂离子电池的应用进行了展望.     

用于锂离子电池的全固态聚合物电解质

用全氟醚作为增塑剂对PEO改性,并与双三氟甲烷磺酰亚胺锂复合,制备了全固态聚合物电解质。采用SEM、交流阻抗、稳态电流法及恒电流恒电压充放电等对固态聚合物电解质的性能进行了测试表征,结果表明:m(PFPE)∶m(PEO)=0.6的固态聚合物电解质膜的电导率30℃时为2.6×10-3 S·cm-1,同条件下电解质溶液电导为8.2×10-3 S·cm-1,二者处于同一个数量级;随PFPE的量增加,锂离子的迁移数增大;与液态电解质电池相比,固态聚合物电解质制成的电池具有更好的循环容量保持特性,固态聚合物电解质电池500次循环的容量保持率在88.1%,液态电解质电池循环容量保持率在64.5%左右;固态聚合电解质有很优异的耐高温安全性,在130℃和150℃下经1~2h热箱试验,用固态聚合物电解质制作的锂离子电池没出现明显体积变化,而相同条件下的液态电解质锂离子电池已发生爆裂或起火。     

锂离子电池用无机固态电解质研究进展

全固态锂离子电池的核心技术是固态电解质，它决定着电池的各种性能。在所有已开发的固态电解质中，无机固态电解质被认为是最可行的电解质之一。基于无机固态电解质的锂离子传导机理，从LISICON型、Garnet型、Perovskite型和NASICON型四个类型，介绍了无机固态电解质当前存在的一些不足，以及近年来所取得的改善研究成果。面向锂离子电池产业快速发展，指出可以掺杂改性和加工方法改善联合实施，以及结合机器学习等人工智能手段，来优化改善方案，以促进全固态锂离子电池的产业化。     

高安全性锂离子电池电解质研究进展

电解质是锂离子电池的重要组成部分,其电化学性能和热稳定性是影响电池安全性能的重要因素.简要介绍了商用锂离子电池电解质的性质以及由其引起的安全问题,从替代电解质材料和电解质添加剂两个方面综述了高安全性锂离子电池电解质的研究现状,着重阐述了离子液体、聚合物电解质、新型锂盐、成膜添加剂和阻燃添加剂等对锂离子电池安全性能提高的最新进展,展望了锂离子电解液的发展方向.     

无溶剂法制备固态电解质膜的研究进展

传统锂离子电池面临着液态电解液泄漏和易燃等安全问题的挑战。采用固态电解质替换液态电解液可以实现锂离子电池的高安全性和高能量密度。然而,传统的固态电解质膜的制备方法,具有复杂的制备过程以及较高的能耗,为其实际应用增添了挑战。无溶剂法制备固态电解质膜省去了传统制备工艺中的溶剂干燥、溶剂回收等步骤,具有节约能源和环境友好的优点。然而,这项制备固态电解质膜的技术在储能领域的应用尚不成熟,有待于进一步的研究和发展。本综述总结了无溶剂法制备聚合物、无机和复合固态电解质膜的研究进展并阐述了无溶剂制备固态电解质膜这项技术在商业化的过程中面临的挑战,最后对这项技术未来在全固态电池中的实际应用做出展望。     

全固态锂电池有机-无机复合电解质研究进展

目前锂离子电池由于使用液态电解液面临着诸多问题，如工作温度范围窄、热稳定性差、容易泄露和生成锂枝晶等。发展全固态锂电池是提升电池能量密度和安全性的可行途径之一，而作为锂电池材料研究热点的有机-无机复合固态电解质，由于其兼具有机物和无机物的优点，有望运用于下一代全固态锂电池之中。本文首先概述了固态电解质的种类及传导机制，而后详细阐述了有机-无机复合固态电解质中聚合物基质和锂盐的选择以及不同维度无机填料对电解质性能尤其是力学性能的影响，最后提出了有机-无机复合固态电解质的研究总结与展望。     

新型固体电解质Li_(8.5)Ga_(0.5)GeP_2S_(12)

制备了一种新型固体电解质Li8.5Ga0.5GeP2S12。用XRD、SEM、恒电流间歇滴定技术(GITT)和恒电流恒电压测试对其物相、形貌、离子导电性、锂离子的扩散系数和电池的充放电特性等进行了分析。Li8.5Ga0.5GeP2S12属于三斜晶系,P1空间群;固态电解质锂离子电池在3.30V、4.01V、4.18V时锂离子扩散系数(14.4×10-10 cm2·s-1、1.47×10-10 cm2·s-1、0.58×10-10 cm2·s-1)和液态电解液组成的锂离子电池的离子扩散系数(17.4×10-10cm2·s-1、2.02×10-10 cm2·s-1、0.75×10-10 cm2·s-1)基本处于一个数量级;固态电解质Li8.5Ga0.5GeP2S12在低倍率下放电容量比液态电解质稍低,而在高倍率下放电容量比液态电解质要高;固态电解质Li8.5Ga0.5GeP2S12有很优异的耐高温安全性,在130℃、2h热箱实验中电池没发生明显体积变化,而相同条件下的液态电解质锂离子电池已发生严重涨气。     

塑料锂离子电池用聚合物电解质性能表征

以导电聚合物作为电解质的塑料锂离子电池被认为是迄今锂电池发展最新水平，研制性能优良的聚合物电解质是生产该种锂离子电池的关键技术，因此对聚合物电解质的表征是必不可少的步骤，电导率，扩散系数，迁移数和电化学窗口是表征聚合物电解质的重要指标，文中介绍了塑料锂离子电池用聚合物电解质性能的表征方法，给出了交流阻抗，浓差极化，断电流，线性伏安扫描等实验方法，并对其作为分析和讨论。     

Nonaqueous Sodium‐Ion Full Cells: Status,Strategies, and Prospects

With ever‐increasing efforts focused on basic research of sodium‐ion batteries (SIBs) and growing energy demand, sodium‐ion full cells (SIFCs), as unique bridging technology between sodium‐ion half‐cells (SIHCs) and commercial batteries, have attracted more and more interest and attention. To promote the development of SIFCs in a better way, it is essential to gain a systematic and profound insight into their key issues and research status. This Review mainly focuses on the interface issues, major challenges, and recent progresses in SIFCs based on diversified electrolytes (i.e., nonaqueous liquid electrolytes, quasi‐solid‐state electrolytes, and all‐solid‐state electrolytes) and summarizes the modification strategies to improve their electrochemical performance, including interface modification, cathode/anode matching, capacity ratio, electrolyte optimization, and sodium compensation. Outlooks and perspectives on the future research directions to build better SIFCs are also provided.     

Overcoming the Interfacial Limitations Imposed by the Solid–Solid Interface in Solid‐State Batteries Using Ionic Liquid‐Based Interlayers

Li‐garnets are promising inorganic ceramic solid electrolytes for lithium metal batteries, showing good electrochemical stability with Li anode. However, their brittle and stiff nature restricts their intimate contact with both the electrodes, hence presenting high interfacial resistance to the ionic mobility. To address this issue, a strategy employing ionic liquid electrolyte (ILE) thin interlayers at the electrodes/electrolyte interfaces is adopted, which helps overcome the barrier for ion transport. The chemically stable ILE improves the electrodes‐solid electrolyte contact, significantly reducing the interfacial resistance at both the positive and negative electrodes interfaces. This results in the more homogeneous deposition of metallic lithium at the negative electrode, suppressing the dendrite growth across the solid electrolyte even at high current densities of 0.3 mA cm^?2. Further, the improved interface Li/electrolyte interface results in decreasing the overpotential of symmetric Li/Li cells from 1.35 to 0.35 V. The ILE modified Li/LLZO/LFP cells stacked either in monopolar or bipolar configurations show excellent electrochemical performance. In particular, the bipolar cell operates at a high voltage (≈8 V) and delivers specific capacity as high as 145 mAh g^?1 with a coulombic efficiency greater than 99%.     

Electrolytes and Electrolyte/Electrode Interfaces in Sodium‐Ion Batteries: From Scientific Research to Practical Application

Sodium‐ion batteries (SIBs) have drawn considerable interest as power‐storage devices owing to the wide abundance of their constituents and low cost. To realize a high performance–price ratio, the cathode and anode materials must be optimized. As essential components of SIBs, electrolytes should have wide electrochemical windows, high thermal stability, and exceptional ionic conductivity. Therefore, improved electrolytes, based on various materials and compositions, are developed to meet the practical demands of SIBs, including organic electrolytes, ionic liquids, aqueous, solid electrolytes, and hybrid electrolytes. Although mature organic electrolytes are currently used in production, aqueous and solid electrolytes show advantages for future applications, as discussed here in detail. Current efforts in modifying electrolytes to optimize their interfacial compatibility with electrodes, leading to longer battery lifetimes and greater safety, are described. The advanced characterization techniques used to investigate the properties of electrolytes and interfaces are introduced, and the reaction processes and degradation mechanisms of SIBs are revealed. Furthermore, the practical prospects of SIBs promoted by high‐quality electrolytes appropriately matched with electrodes are predicted and directions for developing next‐generation SIBs are suggested.     

超级电容器电解质研究进展

电解质作为超级电容器的重要组成部分,对器件性能起着关键性作用。本文对近些年来超级电容器各种电解质,包括水系、有机液体、离子液体、固态/准固态聚合物电解质和氧化还原体系电解质的特点和最新研究成果进行了描述;重点介绍了固态/准固态聚合物电解质的分类及其性能研究概况。提出了发展电位窗口宽、离子电导率高、电化学性能稳定的离子液体和机械强度等综合性能优良的凝胶聚合物电解质是将来超级电容器电解质发展领域的趋势,最后对超级电容器电解质的发展前景进行了展望。     

Altering Mechanical Properties to Improve Electrode Contacts by Organic Modification of Silica-Based Ionogel Electrolytes for Sodium-Ion Batteries

Sodium-ion batteries (SIBs) are a possible candidate to create safe, sustainable, and cost-effective batteries. Solid sodium-ion conducting organically modified ionogel electrolytes are investigated. Silica-based ionogels typically consist of an ionic liquid electrolyte (ILE) confined within a silica matrix and possess high thermal stability, good ionic conductivity, safety, and good electrochemical stability. However, they readily deteriorate when stress is applied, decreasing the electrolyte's and battery's overall performance. The mechanical characteristics of silica can be improved using organic moieties, creating Ormosils®. Silica-based ionogels with phenyl-modified silanes improve the mechanical characteristics by a reduction of their Young's modulus (from 29 to 6 MPa). This is beneficial to the charge-transfer resistance, which decreases after implementing the electrolyte in half cells, demonstrating the improved interfacial contact. Most importantly, the phenyl groups change the interacting species at the silica interface. Cationic imidazolium species pi-stacked to the phenyl groups of the silica matrix, pushing the anions to the bulk of the ILE, which affects the ionic conductivity and electrochemical stability, and might affect the quality of the SEI in half cells. In essence, the work at hand can be used as a directory to improve mechanical characteristics and modify and control functional properties of ionogel electrolytes.     

Stabilizing Na3SbS4/Na interface by rational design via Cl doping and aqueous processing

Solution-synthesis method is attractive for solid electrolytes because it is a facile and scalable process to be used to permeate electrodes and to construct a thin electrolyte coating layer on active materials.In this work,we report Cl-doped Na3SbS4 prepared via aqueous-solution approach.Besides decent ionic conductivity,the aqueous-solution approached electrolyte demonstrates an improved interfacial stability toward Na metal compared to the solid-state sintered one because of the residual hydrate,nanosized microstructure,and Cl incorporation.All-solid-state batteries using the solution-prepared electrolytes have enhanced cycling performance,though the performance still needs to be further improved.     

A Single-Ion Conducting Borate Network Polymer as a Viable Quasi-Solid Electrolyte for Lithium Metal Batteries

Lithium-ion batteries have remained a state-of-the-art electrochemical energy storage technology for decades now, but their energy densities are limited by electrode materials and conventional liquid electrolytes can pose significant safety concerns. Lithium metal batteries featuring Li metal anodes, solid polymer electrolytes, and high-voltage cathodes represent promising candidates for next-generation devices exhibiting improved power and safety, but such solid polymer electrolytes generally do not exhibit the required excellent electrochemical properties and thermal stability in tandem. Here, an interpenetrating network polymer with weakly coordinating anion nodes that functions as a high-performing single-ion conducting electrolyte in the presence of minimal plasticizer, with a wide electrochemical stability window, a high room-temperature conductivity of 1.5 × 10⁻⁴ S cm⁻¹, and exceptional selectivity for Li-ion conduction (t_Li+ = 0.95) is reported. Importantly, this material is also flame retardant and highly stable in contact with lithium metal. Significantly, a lithium metal battery prototype containing this quasi-solid electrolyte is shown to outperform a conventional battery featuring a polymer electrolyte.     

Polymer electrolytes and interfaces in solid-state lithium metal batteries

The polymer electrolyte based solid-state lithium metal batteries are the promising candidate for the high-energy electrochemical energy storage with high safety and stability. Moreover, the intrinsic properties of polymer electrolytes and interface contact between electrolyte and electrodes have played critical roles for determining the comprehensive performances of solid-state lithium metal batteries. In this review, the development of polymer electrolytes with the design strategies by functional units adjustments are firstly discussed. Then the interfaces between polymer electrolyte and cathode/anode, including the interface issues, remedy strategies for stabilizing the interface contact and reducing resistances, and the in-situ polymerization method for enhancing the compatibilities and assembling the batteries with favorable performances, have been introduced. Lastly, the perspectives on developing polymer electrolytes by functional units adjustment, and improving interface contact and stability by effective strategies for solid-state lithium metal batteries have been provided.     

Electrochemo-mechanical effects as a critical design factor for all-solid-state batteries

All-solid-state batteries (ASSBs) using inorganic solid electrolytes (SEs) are in the spotlight for next-generation energy storage devices because of their potential for outstanding safety and high energy density. Recent progress in this field has been primarily based on advances in materials, such as the discovery of SEs with high ionic conductivities and the improvement of interfacial stability in electrodes. However, the use of inelastic SEs causes severe electrochemo-mechanical failures, such as cathode active material (CAM) disintegration, CAM/SE contact loss, and stress build-up during cycling, deteriorating the Li⁺ and e^? transport pathways. Although these concerns have been addressed previously, they have not been contextualized systematically in terms of the mechanical interactions among the components and their impacts on electrochemical performance. Here, we categorize the electrochemo-mechanical effect in ASSBs and its ramifications in terms of stress sources, active materials, composite electrodes, and cell stacks.     

Aliphatic Polycarbonate‐Based Solid‐State Polymer Electrolytes for Advanced Lithium Batteries: Advances and Perspective

Conventional liquid electrolytes based lithium‐ion batteries (LIBs) might suffer from serious safety hazards. Solid‐state polymer electrolytes (SPEs) are very promising candidate with high security for advanced LIBs. However, the quintessential frailties of pristine polyethylene oxide/lithium salts SPEs are poor ionic conductivity (≈10⁻⁸ S cm⁻¹) at 25 °C and narrow electrochemical window (<4 V). Many innovative researches are carried out to enhance their lithium‐ion conductivity (10⁻⁴ S cm⁻¹ at 25 °C), which is still far from meeting the needs of high‐performance power LIBs at ambient temperature. Therefore, it is a pressing urgency of exploring novel polymer host materials for advanced SPEs aimed to develop high‐performance solid lithium batteries. Aliphatic polycarbonate, an emerging and promising solid polymer electrolyte, has attracted much attention of academia and industry. The amorphous structure, flexible chain segments, and high dielectric constant endow this class of polymer electrolyte excellent comprehensive performance especially in ionic conductivity, electrochemical stability, and thermally dimensional stability. To date, many types of aliphatic polycarbonate solid polymer electrolyte are discovered. Herein, the latest developments on aliphatic polycarbonate SPEs for solid‐state lithium batteries are summarized. Finally, main challenges and perspective of aliphatic polycarbonate solid polymer electrolytes are illustrated at the end of this review.