锂离子电池介观尺度光滑粒子水力学模型

针对锂离子电池内耦合电化学反应的多物理传输过程,采用光滑粒子水力学数值技术,开发了可以考虑电极(包括隔膜)介观微结构的数值模型.以电极中固体活性物颗粒尺寸为主要考虑参数,初步探讨了该模型用于电极介观微结构设计的可行性.模型模拟得到放电过程中电池内部Li/Li+浓度场、固/液相电势场以及交换流密度等微观细节分布,以及电池宏观性能如输出电压等,据此可以分析并揭示电池放电过程的基础物理化学机制、电池宏观性能与构成电极的固体活性物颗粒尺寸之间的关联.研究还发现:当阴、阳极固体活性物颗粒尺寸均较小时,固体活性物颗粒内部Li分布更为均匀,电化学反应更均匀发生,电池输出电压最高.     

原子尺度锂离子电池电极材料的近平衡结构

锂离子电池充放电过程中电极材料的结构变化与材料的电化学反应机理和性能密切相关.通过在原子尺度上直接观察脱/嵌锂前后电极材料的近平衡微观结构,有助于从更深层次认识电极反应机理和性能演化规律,对于全面理解材料的电化学行为以及改善锂离子电池性能具有重要的指导意义.本文详述了球差校正扫描透射成像技术在研究电极材料表界面结构及反应机理方面的进展,探讨了未来建立电极材料原子尺度结构与性能相关联可能的研究方向.     

锂离子电池纳微结构电极材料系列研究

纳米储锂电极材料由于奇特的纳米效应与动力学优势,为锂离子电池的发展提供了新的机遇.本文介绍了锂离子电池电极材料的尺寸效应、形貌效应以及电极材料碳包覆的作用;并以作者的近期研究为主,着重讨论了几种"动力学稳定"的纳微结构电极材料和具有"三维混合导电网络"结构的高倍率电极材料.     

可充电池的磁共振研究

快速增长的对安全能源的需求,促使科研工作者不断探索高能量密度的可充锂离子电池(LIBs)。发展原位表征技术能更好地研究电池工作中的锂离子镶嵌机制和电池失效因素。固体核磁共振(NMR)能有效的测试短程化学环境:通过对~1H、~(6,7)Li、~(11)B、~(13)C、~(17)O、~(19)F、~(23)Na和~(31)P等同位素来探测电池材料的微观结构。除了魔角旋转(MAS)高分辨NMR谱图研究电池材料的精细结构之外,核磁共振还能无损地捕获、研究电池材料在充放电循环中的演化。因此,原位核磁共振NMR及成像(MRI)可拓展到电池充放电循环中的锂离子的动态演化以及锂离子浓度的时空分布信息。互为补充地,电子顺磁共振(EPR)及成像(EPRI)能有效地跟踪和捕获电极过渡金属、阴氧离子(O_2~(n-))的氧化还原过程。这些实时捕获的动态信息能更好地指导电极材料的构效、微观设计和电池组装的改进,最终获得优异的电化学性能。     

锂离子电池正极材料的第一性原理研究进展

锂离子电池的发展主要依赖于电极材料的突破,解决现有电极材料存在的问题和预测新型未知材料是提高锂离子电池性能的关键,而第一性原理计算的出现能够较好的满足这一需求。本文介绍了第一性原理计算在锂离子电池正极材料研究方面的原理和应用,并对该原理在正极材料的平均嵌锂电压计算,嵌/脱锂机理、结构稳定性研究及新材料预测等方面的应用进行了详细论述,并指出了这一理论计算工具在电池材料设计过程中的重要性和局限性。     

锂离子电池正极材料的第一性原理

锂离子电池的发展主要依赖于电极材料的突破,解决现有电极材料存在的问题和预测新型未知材料是提高锂离子电池性能的关键,而第一性原理计算的出现能够较好地满足这一需求.本文介绍了第一性原理计算在锂离子电池正极材料研究方面的原理和应用,对该原理在正极材料的平均嵌锂电压计算、嵌/脱锂机理、结构稳定性研究及新材料预测等方面的应用进行了详细论述,并指出了这一理论计算工具在电池材料设计过程中的重要性和局限性.     

锂离子电池电极材料选择

商用锂离子电池发展至今已有20年,为了满足不同方面的社会需求,人们迫切需要新型锂离子电池电极材料.本文首先简要介绍了锂离子电池的相关知识,随后对多种新型锂离子电池正负极材料的制备、改进方法及电化学性能做了详细介绍,最后对各种电极材料的优缺点进行了简要的总结.本文还对锂离子电池在未来的应用进行了展望,以期待锂离子电池更好...     

锂离子电池电极材料固体核磁共振研究进展

对于研究材料的结构变化和考察原子所处的化学环境，固体核磁共振技术是一种有效的手段。通过⁶Li和⁷Li核磁共振谱的变化，可以清楚地了解锂离子电池电极材料中Li与邻近金属或碳原子的配位情况及在充放电过程中对应于锂离子嵌/脱过程中材料的结构变化，对于研究电极材料的电化学性能有重要的意义。本文综述了固体NMR技术在研究锂离子电池电极材料的结构及嵌锂机理方面的一些进展。     

石墨烯及其复合材料在锂离子电池中的应用

石墨烯是一种单原子层厚度的石墨材料,具有独特的二维结构和优异的电学、力学以及热学性能。同时它也是一种具有良好应用前景的锂离子电池电极材料。电极材料的微观结构对其性能有很大影响,利用石墨烯获得具有特殊形貌和微观结构的电极材料,能有效改善材料的各项电化学性能。本文综述了石墨烯及其复合材料在锂离子电池中的应用研究进展。在负极复合材料中,石墨烯不仅可以缓冲材料在充放电过程中的体积效应,还可以形成导电网络提升复合材料的导电性能,提高材料的倍率性能和循环寿命。通过优化复合材料的微观结构,例如夹层结构或石墨烯片层包覆结构,可进一步提高材料的电化学性能。在正极复合材料中,石墨烯形成的连续三维导电网络可有效提高复合材料的电子及离子传输能力。此外,相比于传统导电添加剂,石墨烯导电剂的优势在于能用较少的添加量,达到更加优异的电化学性能。最后对石墨烯复合材料的研究前景进行了展望。     

聚合物锂离子电池界面相容性的研究进展

聚合物锂离子电池作为储能装置在电子产品中具有广泛的应用前景。电极/聚合物电解质(E/P)界面相容性是影响聚合物锂离子电池电导率、安全性、机械性能的重要影响因素之一。研究E/P界面的电化学反应及形成机理,是解决相容性问题的关键。本文综述了近年来有关聚合物锂离子电池E/P界面相容性及相关研究技术的进展,并对聚合物锂离子电池界面相容性的相关研究进行了展望。     

三元锂离子电池容量衰减机理研究进展

三元锂离子电池主要是指使用镍钴锰酸锂（NCM）或镍钴铝酸锂（NCA）作为正极材料的锂离子电池,三元锂离子电池广泛应用于电动汽车、3C电子产品、储能等领域。然而,三元锂离子电池的循环寿命已成为其进一步发展的最大障碍,因此了解三元锂离子电池的容量衰退机理具有重要意义。三元锂离子电池的衰退机理主要包括五个方面：晶体结构的改变和相变、活性材料的损失、电解质的分解和消耗、可脱嵌锂离子的损耗以及固体电解质界面的形成。本文总结了近年来相关方面的研究进展,以期更全面地总结三元锂离子电池的容量衰减机理,并对三元锂离子电池的应用前景进行了展望。     

Power sources for portable electronics and hybrid cars: lithium batteries and fuel cells

The activities in progress in our laboratory for the development of batteries and fuel cells for portable electronics and hybrid car applications are reviewed and discussed. In the case of lithium batteries, the research has been mainly focused on the characterization of new electrode and electrolyte materials. Results related to disordered carbon anodes and improved, solvent-free, as well as gel-type, polymer electrolytes are particularly stressed. It is shown that the use of proper gel electrolytes, in combination with suitable electrode couples, allows the development of new types of safe, reliable, and low-cost lithium ion batteries which appear to be very promising power sources for hybrid vehicles. Some of the technologies proven to be successful in the lithium battery area are readapted for use in fuel cells. In particular, this approach has been followed for the preparation of low-cost and stable protonic membranes to be proposed as an alternative to the expensive, perfluorosulfonic membranes presently used in polymer electrolyte membrane fuel cells (PEMFCs).     

Toward Practical All-solid-state Batteries with Sulfide Electrolyte: A Review

Sulfide-based solid-state electrolytes with ultrahigh lithium ion conductivities have been considered as the most promising electrolyte system to enable practical all-solid-state batteries. However, the practical applications of the sulfide-based all-solid-state batteries are hindered by severe interfacial issues as well as large-scale material preparation and battery fabrication problems. Liquid-involved interfacial treatments and preparation processes compatible with current battery manufacturing capable of improving electrode/electrolyte interface contacts and realizing the mass production of sulfide electrolytes and the scalable fabrication of sulfide-based battery component have attracted considerable attention. In this perspective, the current advances in liquid-involved treatments and processes in sulfide-based all-solid-state batteries are summarized. Then relative chemical mechanisms and existing challenges are included. Finally, future guidance is also proposed for sulfide-based batteries. Focusing on the sulfide-based all-solid-state batteries, we aim at providing a fresh insight on understandings towards liquid-involved processes and promoting the development of all-solid-state batteries with higher energy density and better safety.     

锂电池电极过程的原位电化学原子力显微镜研究进展

随着人类对能源的使用与存储需求不断增加,高能量密度和高安全性能的二次锂电池体系正在被不断地开发与完善.深入理解充放电过程中锂电池内部电极/电解质界面的电化学过程以及微观反应机理,有利于指导电池材料的优化设计.原位电化学原子力显微镜将原子力显微镜的高分辨表界面分析优势与电化学反应装置相结合,能够在电池运行条件下实现对电极/电解质界面的原位可视化研究,并进一步从纳米尺度上揭示界面结构的演化规律与动力学过程.本文总结了原位电化学原子力显微镜在锂电池电极过程中的最新研究进展,主要包括基于转化型反应的正极过程、固体电解质中间相的动态演化以及固态电池界面演化与失效分析.     

锂离子电池LiMn2O4薄膜电极的制备研究进展

尖晶石ＬｉＭｎ２Ｏ４是最有希望替ＬｉＣｏＯ２的新一代锂离子电池阴极材料。高能、轻量、超薄将是未来锂离子电池一个十分重要的发展方向。本文对尖晶石ＬｉＭｎ２Ｏ４的晶体结构作了简要介绍。综述了近年来在ＬｉＭｎ２Ｏ４薄膜电极制备方面的研究进展,包括静电喷雾沉积（ＥＳＤ）、静脉激光沉积（ＰＬＣ）、射频磁溅射（ＲＦＭＳ）等等,并对今后的研究方向进行了展望。     

Critical aspects in the development of lithium–air batteries

Intensive research has been done on lithium–air batteries, especially in the last few years. Due to their very high theoretical specific energy, lithium–air batteries are one of the most promising candidates to power future electric vehicles. However, this new technology is in a very early stage of development, and several challenges must be overcome before there will be a commercially viable product. This review describes the most important critical aspects in the development of lithium–air batteries: the electrocatalysis of the oxygen electrode reactions, the degradation of the electrolyte and the oxygen electrode components, the structure of the oxygen electrode, and the passivation of the oxygen electrode during the discharge of the battery. Recent works in these areas are critically reviewed, and suitable research strategies to address these issues are discussed.     

From Lithium‐Ion to Sodium‐Ion Batteries: Advantages,Challenges, and Surprises

Mobile and stationary energy storage by rechargeable batteries is a topic of broad societal and economical relevance. Lithium‐ion battery (LIB) technology is at the forefront of the development, but a massively growing market will likely put severe pressure on resources and supply chains. Recently, sodium‐ion batteries (SIBs) have been reconsidered with the aim of providing a lower‐cost alternative that is less susceptible to resource and supply risks. On paper, the replacement of lithium by sodium in a battery seems straightforward at first, but unpredictable surprises are often found in practice. What happens when replacing lithium by sodium in electrode reactions? This review provides a state‐of‐the art overview on the redox behavior of materials when used as electrodes in lithium‐ion and sodium‐ion batteries, respectively. Advantages and challenges related to the use of sodium instead of lithium are discussed.     

高性能锂离子电池正极黏合剂研究进展

正极黏合剂是维持锂离子电池正极结构稳定性的关键材料,对于锂离子电池的能量密度及安全性具有重要作用.本文综述了锂离子电池正极黏合剂材料的研究及应用进展,重点介绍了锂离子电池正极黏合剂对于正极材料及锂离子电池电化学性能的影响,详细总结了以聚偏氟乙烯(PVDF)、聚酰亚胺(PI)、功能性聚合物黏合剂为代表的油溶性黏合剂和以聚丙烯酸(PAA)、羧甲基纤维素(CMC)为代表的水溶性黏合剂的特点:PVDF具备良好的化学稳定性,黏合效果较好,但耐高温性能差且在电解液中易溶胀;PI的耐高温性能优异,机械性能较好,但成本相对较高;功能性聚合物黏合剂具备良好的导电性,可有效抑制Li-S锂电池中多硫化物的穿梭效应,但制备工艺复杂;PAA的柔性较好,抗高压能力较强,但是力学性能较差;CMC具有良好的分散性,机械强度较大,因脆性较大需与丁苯橡胶(SBR)配合使用.结合已有的研究报道,探讨了高性能锂离子电池先进正极黏合剂材料的未来发展方向及前景.     

Challenges and Development of Composite Solid Electrolytes for All-solid-state Lithium Batteries

All-solid-state lithium batteries are considered to be a new battery system with great development potential and application prospects due to the advantages of high energy density and high security.As a key component of all-solid-state lithium batteries,the development of solid-state electrolytes has received extensive attention in recent years,but most solid electrolytes still exhibit problems,such as low ion conductivity and poor interface compatibility.The design of composite solid-state electrolyte materials with both excellent electrochemical and mechanical properties is an effective way to develop all-solid-state lithium batteries.This review introduces different types of pure component solid electrolytes and analyzes their respective advantages and characteristics firstly.Furthermore,the research progress of composite electrolytes in preparation method,ionic conduction,suppression of lithium dendrites,and the improvement of electrochemical performances are reviewed from the perspective of composite electrolyte structure design,which is to meet different performance requirements.And the future development direction and trend of composite electrolytes are prospected.     

Structure Design and Performance of LiNixCoyMn1‐x‐yO2 Cathode Materials for Lithium‐ion Batteries: A Review

Lithium‐ion batteries are now considered to be the technology of choice for future hybrid electric and full electric vehicles to address global warming. One of the challenges for improving the performance of lithium ion batteries to meet increasingly demanding requirements for energy storage is the development of suitable cathode materials. The recent advancement of lithium nickel cobalt manganese oxides are investigated as advanced positive cathode materials for lithium‐ion batteries. This review aims at providing the reader with an understanding of the critical scientific challenges facing the development of LiNi_xCo_yMn_1‐x‐yO₂ materials, the latest developments in crystal structure, synthesis methods, and structure designs to unravel the mechanisms of charge and mass transport processes associated with battery performance, and the outlook for future‐generation batteries that exploit gradient structures materials for significantly improved performance to meet the ever‐increasing demands of emerging technologies.