Highly reinforce the interface stability using 2-Phenyl-1H-imidazole-1-sulfonate electrolyte additive to enhance the high temperature performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/graphite batteries

This work develops 2-Phenyl-1H-imidazole-1-sulfonate(PHIS)as a multi-functional electrolyte additive for H2O/HF scavenging and film formation to improve the high temperature performance of LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/graphite batteries.After 450 cycles at room temperature(25℃),the discharge capacity retentions of batteries with blank and PHIS-containing electrolyte are 56.03%and 94.92%respectively.After 230 cycles at high temperatures(45℃),their values are 75.30%and 88.38%respectively.The enhanced electrochemical performance of the batteries with PHIS-containing electrolyte is supported by the spectroscopic characterization and theoretical calculations.It is demonstrated that this PHIS electrolyte additive can facilitate the construction of the electrode interface films,remove the H2O/HF in the electrolyte,and improve the electrochemical performance of the batteries.This work not only develops a sulfonate-based electrolyte but also can stimulate new ideas of functional additives to improve the battery performance.

Latest progresses and the application of various electrolytes in high-performance solid-state lithium-sulfur batteries

With the emergence of some solid electrolytes(SSEs)with high ionic conductivity being comparable to liquid electrolytes,solid-state lithium-sulfur batteries(SSLSBs)have been widely regarded as one of the most promising candidates for the next generation of power generation energy storage batteries,and have been extensively researched.Though many fundamental and technological issues still need to be resolved to develop commercially viable technologies,SSLSBs using SSEs are expected to address the present limitations and achieve high energy and power density while improving safety,which is very attractive to large-scale energy storage systems.SSLSBs have been developed for many years.However,there are few systematic discussions related to the working mechanism of action of various electrolytes in SSLSBs and the defects and the corresponding solutions of various electrolytes.To fill this gap,it is very meaningful to review the recent progress of SSEs in SSLSBs.In this review,we comprehensively investigate and summarize the application of SSEs in LSBs to determine the differences which still exist between current progresses and real-world requirements,and comprehensively describe the mechanism of action of SSLSBs,including lithium-ion transport,interfacial contact,and catalytic conversion mechanisms.More importantly,the selection of solid electrolyte materials and the novel design of structures are reviewed and the properties of various SSEs are elucidated.Finally,the prospects and possible future research directions of SSLSBs including designing high electronic/ionic conductivity for cathodes,optimizing electrolytes and developing novel electrolytes with excellent properties,improving electrode/-electrolyte interface stability and enhancing interfacial dynamics between electrolyte and anode,using more advanced test equipment and characterization techniques to analyze conduction mechanism of Li^(+)in SSEs are presented.It is hoped that this review can arouse people’s attention and enlighten the development of functional materials and novel structures of SSEs in the next step.

Benzoselenol as an organic electrolyte additive in Li-S battery

Lithium-sulfur(Li-S)battery is one of the promising high-energy battery systems for future use.However,the shuttle effect due to the dissolved lithium polysulfides in ether electrolyte hampers its practical application.Applying electrolyte additives in Li-S battery has been widely acknowledged as an effective way to reduce the shuttle effect and improve cycling efficiency.In this work,benzoselenol(PhSeH)is used as an organic electrolyte additive in Li-S battery.It reacts with elemental sulfur to form phenyl selenosulfide,altering the redox pathway of the cathode with the regeneration of S8 at the end of charge and enabling new redox reactions with high reversibility.The Li-S coin cell with an optimized amount of PhSeH in the electrolyte delivers a high discharge capacity of 1,436 mAh·g^(−1)and a capacity retention of 92.86%in 200 cycles,and exhibits lower discharge overpotential in comparison to the cell with blank electrolyte.The Li-S pouch cell with a low electrolyte/sulfur(E/S)ratio of 4.0μL·mg^(−1)shows a discharge capacity of 1,398 mAh and excellent capacity retention for 20 cycles.

Progress in Gel Polymer Electrolytes for Sodium-Ion Batteries

Sodium-ion battery is a potential application system for large-scale energy storage due to the advantage of higher nature abundance and lower production cost of sodium-based materials.However,there exist inevitably the safety problems such as flammability due to the use of the same type of organic liquid electrolyte with lithium-ion battery.Gel polymer electrolytes are being considered as an effective solution to replace conventional organic liquid electrolytes for building safer sodium-ion batteries.In this review paper,the authors present a comprehensive overview of the research progress in electrochemical and physical properties of the gel polymer electrolyte-based sodium batteries.The gel polymer electrolytes based on different polymer hosts namely poly(ethylene oxide),poly(acrylonitrile),poly(methyl methacrylate),poly(vinylidene fluoride),poly(vinylidene fluoride-hexafluoro propylene),and other new polymer networks are summarized.The ionic conductivity,ion transference number,electrochemical window,thermal stability,mechanical property,and interfacial issue with electrodes of gel polymer electrolytes,and the corresponding influence factors are described in detail.Furthermore,the ion transport pathway and ion conduction mechanism are analyzed and discussed.In addition,the advanced gel polymer electrolyte systems including flame-retardant polymer electrolytes,composite gel polymer electrolytes,copolymerization,single-ion conducting polymer electrolytes,etc.with more superior and functional performance are classified and summarized.Finally,the application prospects,development opportunities,remaining challenges,and possible solutions are discussed.

Lithium Hexamethyldisilazide Endows Li||NCM811 Battery with Superior Performance

The construction of stable cathode electrolyte interphase(CEI)is the key to improve the NCM811 particle structure and interfacial stability via electrolyte engineering.In He’s work,lithium hexamethyldisilazide(LiHMDS)as the electrolyte additive is proposed to facilitate the generation of stable CEI on NCM811 cathode surface and eliminate H_(2)O and HF in the electrolyte at the same time,which boosts the cycling performance of Li||NCM811 battery up to 1000 or 500 cycles with 4.5 V cut-off voltage at 25 or 60℃.

锂离子电池电解液安全性的影响因素及改进措施

锂离子电池由于能量密度高、高电压和维护成本低等优点而被大家使用.但在使用它们的过程中存在燃烧、爆炸等安全问题.电解液是锂离子电池中最易燃的组分,所以其与锂电池的安全性息息相关.改进电解液是提高锂离子电池安全性的关键方法.首先探讨了影响锂离子电池电解液安全性的因素,然后提出了改善措施,主要包括添加阻燃剂和抗过充添加剂来降低风险.

锂离子电池耐燃电解液的研究进展

锂离子电池已广泛应用于中小型设备储能,热失控是导致电池发生安全问题的主要原因。电解液是热失控链条中的重要一环,降低其可燃性有助于保障电池安全。针对目前商业电解液闪点低、易燃等问题,已有很多解决方案。总结几种锂离子电池耐燃电解液体系,包括含磷、含氟和含硅有机阻燃剂等不燃体系。含磷阻燃剂的阻燃效率及电池兼容性等综合性能较好,含氟代溶剂闪点高但阻燃效率一般,而硅基阻燃剂热稳定性好但很难作为纯溶剂使用。对锂离子电池耐燃电解液的发展前景进行展望。

锂离子电池低温电解液的研究进展

锂离子电池在低温条件下运行时,电池的电化学性能已经不能达到最佳状态,存在容量迅速恶化的问题,这限制了其在极寒地区以及航空、国防军事等特殊领域的应用。因此,提高电池的低温性能成为研究热点之一。本文通过对相关文献的探讨,综述了改善锂离子电池低温性能的策略,着重介绍了电导率较高的新型锂盐、由低熔点和高介电常数组成的混合溶剂以及有助于形成稳定SEI膜的成膜添加剂对电池低温性能的影响,重点分析了上述因素对于锂离子电池低温性能的影响机制。综合分析表明,Li+的溶剂化结构与去溶剂化过程在电极界面上的行为直接决定了电池的低温性能。本文强调了从电解液的溶剂化结构入手来设计低温电解液的重要性,为未来低温锂离子电池开发提供了新思路。

锂离子电池用低温电解液的研究进展

在低温下由于电解液流动性下降、Li+传输能力降低导致的锂离子电池容量快速衰减、循环寿命缩短等问题,日益受到重视。分析锂离子电池低温性能的影响因素,如电解液的本体性质与电解液/电极界面反应。着重从溶剂、锂盐和添加剂等方面,总结低温电解液的研究进展,如开发高低温兼顾的电解液、制备锂盐及探讨不同添加剂的协同作用。对低温电解液的发展提出展望,如制备局部高浓度电解液或发展全氟化电解液等。

通过桥接全氟阻燃剂和高氟化电解液构筑高安全型钠离子电池

因钠储量丰富和相对价格便宜,钠离子电池(SIBs)已明确为大规模储能的首选电化学器件,其中电解液是SIBs的重要组成部分.众所周知,传统碳酸酯类电解液的挥发性和易燃性,对电池的安全性能产生重大的影响.因此,开发高安全性的电解液已成为钠离子电池领域重点研究方向之一.本工作提出使用1-(2,2,2-三氟乙基)-1,1,2,2-四氟乙基醚(TTE)桥接全氟阻燃添加剂全氟丁基硫酰氟(PFSF)和碳酸酯基电解液提升电解液的阻燃性能,同时有效提升了正极材料Na3V2(PO4)3(NVP@rGO)的电化学性能.高度氟化的电解液可在充放电过程中在正负极表面构建致密均匀的保护层,使用电解液1.0 M NaTFSI+碳酸丙烯酯(PC)/氟代碳酸乙烯酯(FEC)/TTE(3/3/4,V)+0.5%(体积分数)PFSF的Na/NVP@rGO半电池在200次循环后的容量保持率可维持在88.0%,明显优于传统碳酸酯基电解液,这为安全型钠离子电池的设计提供新思路.

锌离子电池低温性能研究进展

新兴的可充电锌离子电池具有高安全性、环境友好、低成本、操作简单等优势,因此成为极具应用前景的下一代储能设备之一。然而,其在低温条件下展现出较低的放电容量以及功率密度,有时甚至无法正常运行,严重制约可充电锌离子电池的实用性。因此,本文对近期相关文献进行探讨,从电极材料的设计、优化电解质以及改进其他组件三个方面综述了提高锌离子电池低温性能的策略,着重介绍了晶体工程和组分设计在提高电极材料低温离子传导率方面的作用机制。对于电解质优化策略,重点分析了水系高浓度电解质、有机电解质、准固态/固态电解质、电解质添加剂、共晶电解质五种方法对降低电解质凝固点和提升锌离子电池低温电化学性能的机理。此外,简要阐述了高亲水性黏结剂以及高电导率隔膜等改进方法。综合分析表明,通过晶体工程、准固态/固态电解质和电解质添加剂等多种策略的协同耦合,有望实现研制具有高比容量、长循环稳定性和大倍率性能的低温锌离子电池。

凝胶电解质软包钠离子电池的研究

近年来,钠离子电池因其在成本和低温性能方面具有独特优势而被广泛关注.由于层状氧化物正极与锂离子电池三元正极材料类似的制备工艺被率先推出,并将其与硬碳负极搭配组建钠离子电池.但是,由于钠离子电池层状氧化物残碱高、稳定性欠缺,在长循环过程中易引发电解液氧化分解而导致电芯产气,限制了软包钠离子电池的应用.本文采用凝胶电解质策略构建了凝胶电解质软包钠离子电池,并研究了该电池的电化学性能.结果表明,凝胶电解质对抑制电芯循环产气有显著作用,同时可以提高电芯的安全性能.

2,3-吡啶二羧酸酐用于高电压锂离子电池电解液

将2,3-吡啶二羧酸酐(PDA)作为功能型添加剂加入电解液中,可拓宽电解液的氧化还原窗口,并先于溶剂在正负极表面形成保护膜。添加2.0%PDA后,钴酸锂/石墨全电池在85℃下存储18 h,厚度膨胀率从37.0%降低至8.4%;45℃下,以1.0 C在3.0~4.5 V循环600次,容量保持率从58.3%提升至84.9%;在45℃浮充测试中,含2.0%添加剂的电池78 d后厚度膨胀率仅为9.7%。过多的PDA会导致负极阻抗显著增加,出现析锂现象。综合考虑常温和高温性能,PDA添加质量分数建议为1.0%。

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。

有机硅在锂离子电池电解质中的应用

有机硅因其具有本身结构所决定的优异耐高温性和稳定性,将其应用于锂离子电池电解质中,可提高锂离子电池的安全性。综述了有机硅化合物在锂离子电池聚合物电解质和液态电解质中的应用形式及研究现状,包括作为聚合物电解质的组分、作为液态电解质的溶剂或添加剂,并详细介绍了作者所在研究团队近年来在锂离子电池含有机硅化合物电解质材料制备及研究方面的探索成果,同时探讨了其发展及应用前景。

宽温域锂离子电池功能电解液的研究进展

分析锂离子电池在低温工作条件下的性能劣化机理,阐述溶剂物理性质对电解液低温性能的影响规律,总结目前通过低黏度及低熔点的溶剂组分、低阻抗的成膜添加剂以及新型锂盐来改善电池低温性能的研究工作。同时,探讨锂离子电池在高温工作条件下容量衰减机制,综述目前改善锂离子电池高温性能的主要方法,包括采用高温成膜添加剂、耐高温锂盐以及锂盐稳定剂。在此基础上指出目前宽温域锂离子电池发展面临的主要挑战,展望锂离子宽温域电解液的发展趋势。

腈基功能化有机硅电解液添加剂对LiFePO4电池低温性能的影响

合成了一种腈基功能化有机硅化合物3-氰乙基-二乙氧基-甲基硅烷(DESCN),并对其化学结构和电化学窗口进行了表征.采用恒流充放电、扫描电子显微镜(SEM)、X射线光电子能谱(XPS)及电化学阻抗谱(EIS)等方法研究了DESCN添加剂对LiFePO4电池低温性能的影响.结果表明,DESCN化合物能够在电极表面参与形成更薄、更均匀且致密的固体电解质界面(SEI)膜,抑制电解液副反应的发生,减小界面膜阻抗,有利于低温下电极/电解液界面的Li^+扩散和电荷转移,从而提高LiFePO4电池的低温性能.

高安全性锂电池电解液研究与应用

锂离子电池(LIBs)由于具有较高的能量密度和良好循环稳定性而成为应用最广泛的储能设备之一。但是,其安全问题极大的限制了LIBs的生产及应用。LIBs的安全问题主要是由电池系统的热失控引起的,近年来,科学家们针对引起电池热失控的原因进行了研究,表明固体电解质界面(SEI)膜的分解是电池热失控的起点,随后电解液会与正负极材料发生反应,而目前使用的电解液具有闪点低、高度可燃等特点,存在着较大的安全隐患。因此,使用高安全性电解液可以有效提高LIBs的安全性。本文从可替代易燃的有机电解液角度,阐述了提高电解液安全的理论方法与技术途径,包括阻燃电解液、自身不易燃电解液、智能电解液以及水系电解液等方面。这些技术方法,还有望应用于有机液流电池体系,为高安全性大容量储能系统研究提供借鉴。

导电剂及电解液对锂离子电池低温性能的影响

采用恒流恒压充放电方法研究了阴阳极中添加不同的导电剂和注入不同的电解液对锂离子电池低温性能的影响。运用扫描电镜法(SEM)观察了添加碳纳米管导电剂的阴阳极表面形貌,并分析了碳纳米管导电剂对电池性能的影响。分析了不同电解液对锂离子电池低温的影响。结果表明,不同温度下,影响锂离子电池低温性能的因素不同。

磷酸三苯酯对锂离子电池安全性及电化学性能的影响

研究了磷酸三苯酯(TPP)含量对1mol·L-1LiPF6/EC:DEC:EMC(1:1:1)+1.5%VC电解液的电化学稳定性、热稳定性及电导率的影响,结果表明:10%以下TPP添加剂的引入提高了电解液的热稳定性,几乎不影响电解液的电化学窗口,但是该添加剂降低了电解液的电导率。研究了TPP对方型电池的电化学性能及安全性的影响,充放电测试结果表明,TPP的使用会降低电池的循环性能,6%以下的TPP含量对电池的循环性能影响较小;热冲击、针刺及过充安全性测试结果表明,4%～8%含量的TPP能够改善电池的150℃热冲击能力,降低针刺过程中电池的表面温度,提高了锂离子电池的安全性。此外,交流阻抗(EIS)、扫描电镜(SEM)及X射线光电子能谱(XPS)分析表明,TPP对循环性能影响的主要原因是正负极表面过多SEI膜的形成及负极片的部分破裂。