共查询到19条相似文献,搜索用时 156 毫秒
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中间相炭微球在锂离子电池负极材料的应用进展 总被引:1,自引:0,他引:1
中间相炭微球(MCMB)具有良好锂离子扩散性、导电性和机械稳定性等优势,是目前应用广泛、综合性能优异的锂离子电池负极材料,但较低理论比容量是制约其发展的关键因素。为了获得性能优良的MCMB基锂离子电池负极材料,改性修饰和复合材料已然成为目前研发重点。笔者论述了碳结构、表界面和复合材料等微观结构设计对MCMB负极材料电化学性能的影响。从碳堆积结构类型、有序性、层间距以及球体粒径大小等方面,论述了碳结构微观设计对MCMB电化学性能的影响。发现具有乱层结构的MCMB在充放电过程中内部产生应力较小,且碳结构较稳定,具有优异循环稳定性;内部具有大量微孔或碳层间距较大的MCMB,在充放电过程中可提高锂离子在电极中的迁移速率,并提供更多的储锂空间,一般具有优良的充放电比容量和倍率性能;小粒径MCMB具有较短的锂离子迁移路径和随之增加的比表面积,通常具有较好倍率性能,伴随着可逆比容量和充放电效率的衰减。从表界面碳层改性、包覆和掺杂改性等方面,论述了表界面改性对MCMB电化学性能的影响。表面碳层修饰可增加MCMB与电解液的相容性及其比表面积,提高了与电解液的接触面积及贮锂容量,改善了锂离子电池负极材料的电化学性能;另外,MCMB表面包覆一层无定型碳,可避免其表面与电解液直接接触,减少电化学副反应的产生,提升其可逆比容量。从碳活性物质复合材料、非碳活性物质复合材料等方面,论述了复合材料微观结构设计对MCMB电化学性能的影响。碳活性物质可降低MCMB内部碳层结构的有序性,减少锂离子嵌入过程中的内部应力,提升MCMB循环稳定性。非碳活性物质诱导MCMB生成更加有序的碳层结构,提高MCMB的比表面积,从而改善MCMB表面与电解液分子的接触能力及其嵌锂性能,有利于提升MCMB负极材料可逆比容量、循环性能和倍率性能。MCMB具有高碳层间距和多缺陷位点等结构特征,有利于钠离子自由脱嵌,应用于钠离子电池时具有良好的可逆比容量、循环稳定性和倍率性能。MCMB的不规则定向层状结构经活化等处理具有较高比表面积,可应用于超级电容器电极材料。最后提出在高性能锂离子电池电极材料快速发展的需求下,从微观结构角度设计MCMB纳米复合材料将是MCMB负极材料的研究重点。 相似文献
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以水溶液为电解液的水系锂离子电池体系因其功率高、安全性好且成本低廉得到广泛的研究。由于水系电解液的电化学窗口较窄(≈1.23V),在选择水系锂离子电池正极材料时便受到了一定的限制。尖晶石锰酸锂LiMn_2O_4由于合适的充放电电压平台和较好的热稳定性,而且来源广、成本低、合成工艺简单、环境友好等特点,被认为是最具发展前景的水系锂离子电池正极材料。然而LiMn_2O_4在充放电过程中锰溶解导致电池较差的循环稳定性,这在很大程度上限制了其应用。LiMn_2O_4在水系电解液中的循环稳定性,尤其是高温下的循环稳定性,需要研究者深入探究。围绕LiMn_2O_4材料的合成与结构设计,研究了其在水系电解液中容量衰减机理,并基于LiMn_2O_4正极材料建立了一系列具有优异电化学性能的新型水系储能体系。 相似文献
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电解液对锂离子电池性能的影响 总被引:1,自引:0,他引:1
锂离子电池的性能与电解液有着密切的关系。电解液的组成主要是:有机溶剂、锂盐、添加剂。本文综述了电解液组成对锂离子电池电化学性能的影响规律;探讨了电解液量对锂离子电池性能的影响以及不同正极材料锂离子电池对电解液量的需求。 相似文献
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磷酸三苯酯对锂离子电池安全性及电化学性能的影响 总被引:1,自引:0,他引:1
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。 相似文献
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在锂离子电池电解液1 mol/L六氟磷酸锂/碳酸乙烯酯+碳酸二甲酯+碳酸甲乙酯(体积比为1∶1∶1)溶液中添加丁二酸酐作为提高电池充放电效率的添加剂。 采用恒流充放电测试、循环伏安曲线、线性伏安曲线和电化学阻抗谱等手段,研究了添加剂丁二酸酐对电解液电化学稳定窗口的影响,以及丁二酸酐与锰酸锂材料的相容性。结果表明:在电解液中添加2%(质量分数)的丁二酸酐,提高了LiMn2O4/Li电池常温和高温容量保持率。丁二酸酐可以优先于基础电解液发生少量氧化分解,从而降低了LiMn2O4/Li电池的极化。同时,丁二酸酐也可降低电池循环过程的阻抗。 相似文献
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锰酸锂(LiMn2O4)是作为目前性价比最高的商业化锂离子电池正极材料,成为近年来电池研究的热点。但该材料在高温时,由于Mn离子较易溶解于电解液中,制约其广泛应用。本研究中,采用SiO2对其表面进行包覆,减少了活性材料与电解液的直接接触。并通过x-射线衍射、扫描电镜(SEM)、充放电循环测试对合成产物的组成、结构、形貌和电化学性能进行表征,进而研究影响产品的高温性能的主要因素,并筛选出较为合适的改性条件以提高锂电池正极材料LiMn2O4的电化学性能。 相似文献
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镁离子电池因其比容量高、资源丰富、环境友好、安全性高(无枝晶)等优势,在储能电池领域脱颖而出.然而,镁金属负极在液态电解质中易钝化,导致其电化学性能不佳.因此,开发高效适用的固态电解质对实现高性能、实用化镁离子电池至关重要.聚合物电解质具有优异的机械稳定性、电化学稳定性、热稳定性且离子电导率高、成本低.但镁离子较高的电荷密度和较强的溶剂化作用限制了其在固态电解质中的解离与扩散.从纯固态聚合物电解质、凝胶聚合物电解质、复合聚合物电解质3个方面综述了国内外聚合物基镁离子固态电解质的离子电导率对解决镁金属负极钝化效应的贡献及其应用研究进展,指出聚合物基镁离子固态电解质当前面临的挑战并对其研究方向进行了建议和展望. 相似文献
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Jie Shu Miao Shui Fengtao Huang Dan Xu Yuanlong Ren Lu Hou Jia Cui Jinjin Xu 《Electrochimica acta》2011,(8):3006
The chemical and electrochemical stability of Cu current collectors in electrolyte for lithium-ion batteries is investigated. During long-term storage, the surface section of Cu foil is oxidized to copper compounds along with the reduction reaction of electrolyte. A continuous surface film can be formed on the Cu current collector after the foil is immersed in electrolyte for lithium ion batteries at room temperature for 30 days. This surface film is composed of inorganic compounds located in the inner layer and organic/inorganic mixed components stayed outside. It comes from the spontaneous reaction at the interface between Cu foil and electrolyte for the existence of trace water in electrolyte. Different from SEI film spontaneous formation during storage, surface film generated on Cu foil during electrochemical process shows different characteristic and mechanism. By using metal lithium as counter electrode, SEI film on Cu foil in Cu foil/metal Li battery is formed from surface chemical species floating from lithium counter electrode and electrochemical oxidation/reduction process. In contrast, thinner SEI film can be generated merely from electrochemical electrolyte decomposition and precipitation. All the evidences reveal that the structure of SEI film from different conditions is similar, which shows inorganic fluorides located in the inner layer and organic/inorganic mixed lied in the outer layer. 相似文献
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《Ceramics International》2023,49(18):29375-29390
Currently, the safety of lithium-ion batteries has attracted much attention. All-solid-state batteries (ASSBs) are promising replacements for liquid-electrolyte lithium-ion batteries due to their high energy density and excellent safety. The choice of electrolyte is the most critical part of ASSBs. Li7La3Zr2O12 (LLZO)-based solid-state electrolytes (SSEs) render high energy density, wide electrochemical window and high lithium-ion mobility. However, their low lithium-ion conductivity compared with liquid organic electrolytes and rigid interfacial contact at electrode/electrolyte interface mainly hinder the development of LLZO-based ASSBs. Herein, we review recent progress in the area of LLZO-based SSEs by discussing the structure and transport mechanism of lithium (Li)-ions of LLZO. Also, we summarize bottleneck problems and corresponding solutions, providing theoretical basis and technical support for the development of LLZO-based ASSBs. Finally, future prospects of LLZO-based ASSBs are discussed in next-generation energy storage systems. 相似文献
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The characteristics of electrochemically synthesized polythiophene electrodes have been examined in view of their application in rechargeable lithium, organic electrolyte batteries. The kinetics of the electrochemical doping process of polythiophene in LiClO4-propylene carbonate electrolyte are quite fast, especially for polymers grown from the 2,2′-dithiophene dimer. The polythiophene electrodes behave very satisfactorily in terms of charge-discharge efficiency and cyclability. However, also this type of electrodes seems to be affected by the self-discharge processes commonly experienced by semiconducting polymers in lithium, organic electrolyte batteries. 相似文献
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目前,锂离子电池已经广泛地应用于交通、通讯、便携式电子产品及电动工具等领域。传统的锂离子电池采用液体电解液,存在易挥发、易泄漏、抗冲击性能差等缺点,存在安全隐患。全固态电解质具有热稳定性高、循环寿命长、抗震动性能好等优点,是锂离子电池取代液体电解液的一种理想替代方案。硫化物电解质体系具有离子导电率高、制备简便、电化学窗口宽等优点,已经成为全固态锂离子电池的研究热点。综述了全固态锂电池Li2S-P2S5基电解质的最新研究进展,总结了各种性能改进方法,并对其应用前景做了展望。 相似文献
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Additives-containing functional electrolytes for suppressing electrolyte decomposition in lithium-ion batteries 总被引:2,自引:0,他引:2
Several olefinic compounds such as vinyl acetate, divinyl adipate and allyl methyl carbonate were studied as additives for propylene carbonate (PC)-based electrolytes in lithium-ion battery, which kind of electrolytes always exfoliate graphitic carbon and decompose drastically to liberate organic gas. Three kinds of graphitic carbons commonly used in lithium-ion batteries, namely, natural graphite, MCMB 6-28 and MCF were chosen to test the decomposition-suppressing ability of additives. The effects of the type of graphitic anodes and the structure of additives on the electrolyte decomposition have been investigated in the terms solid electrolyte interface (SEI) formation, which was characterized by cyclic voltammetry (CV), ac impedance, SEM, XPS analyses, and auger electron spectroscopy (AES). The electrochemical performance of the additives-containing electrolytes in combination with LiCoO2 cathode and graphitic carbon anode was also tested in coin cells. 相似文献
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近年来随着社会的发展和科技的进步,锂离子电池已成为重要的主流动力电池之一。分别从溶剂和添加剂2个方面综述了基于LiPF6的锂离子电池电解液的发展现状,详细介绍了适用于锂离子电池电解液的溶剂和添加剂,应用于锂离子电池电解液的常用有机溶剂有碳酸酯类、醚类和羧酸酯类有机溶剂,添加剂以其作用目的区分,可分为SEI成膜添加剂、导电添加剂、稳定添加剂、控制水分和游离酸添加剂、抗过充添加剂、阻燃添加剂及浸润性添加剂等;展望了锂离子电池电解液的研究方向。 相似文献