锂离子电池正极材料LiFe02的研究进展。

锂离子电池正极材料LiFe02资源丰富、价格低廉、污染小、理论比容量高，应用潜力大。但LiFeOz结构类型多、电化学行为独特，合成方法对其结构性能影响大。综述了近年来国内外LiFeOz化合物的研究进展，阐述了不同类型LiFeOa的结构特点、合成方法、电化学性能等，介绍了LiFe02在首次充放电过程中可能的反应机理，总结...     

锂离子电池富锂正极材料xLi2MnO3·（1-x）LiMO2(M=Co,Fe,Ni1/2Mn1/2…)的研究进展

新一代固溶体富锂正极材料xLi2MnO3.(1-x)LiMO2(M=Co,Fe,Ni1/2Mn1/2…)具有高比容量、优秀的循环能力以及新的电化学充放电机制,可能被用做新型高比能量锂离子电池正极材料.本文介绍了富锂正极材料的结构、合成方法、电化学性能研究,探讨了影响其电化学性能的若干因素.并对其进行的各种改性研究进行了概述,分析总结了不同富锂正极材料所具有的特性和发展趋势.     

软化学法合成正交结构LiMnO_2及其电化学性能

研究以氢氧化锂和三氧化二锰为原料,用软化学法制备具有正交结构的锂离子电池正极材料LiMnO2。用X射线衍射法确定了材料的结构,用扫描电镜考察了材料形貌和反应时间的关系,观察结果显示得到的LiMnO2的粒子尺寸在300~500nm。结合循环伏安法和交流阻抗分析研究了合成条件对材料组织结构、尺寸与电化学性能的影响。材料的电化学性能测试结果表明,合成的正交扭曲结构LiMnO2(o-LiMnO2)材料在电化学过程中初期表现了较好的电化学性能。但材料在电化学过程中逐步向尖晶石结构相LiMn2O4转变,容量产生衰减,其循环寿命有待更进一步改善。     

多孔TiO_2的合成及其电化学性能研究(英文)

以介孔碳为模板,成功合成了具有较大比表面积的多孔TiO_2,并研究了煅烧时间对所获材料结构及电化学性能的影响.采用X射线粉末衍射、场发射扫描电镜、高分辨透射电镜、氮气吸附-脱附实验和电化学测试对合成的材料进行了表征.测试结果表明所合成的材料是由很小的纳米颗粒组成,表面积大,孔分布窄.经500℃热处理2h的样品为锐钛矿型,继续延长热处理时间至12h,所得样品出现了金红石相,且12h所得材料的初始容量高于2h所得样品,这可能和样品的结晶度有关.     

Na_3V_2(PO_4)_3/C复合材料的制备及电化学性能研究

利用不同的方法合成了Na_3V_2(PO_4)_3/C复合材料,通过X射线衍射、红外光谱、扫描电镜、循环伏安、交流阻抗等方法对Na_3V_2(PO_4)_3/C材料进行了结构表征及性能测试。通过改变合成方法,考察了不同合成路径对于材料结构、微观形貌及电化学性能的影响。研究发现,利用水热法合成的Na_3V_2(PO_4)_3/C复合材料的颗粒呈类球形,粒径尺寸为50nm。电化学性能测试表明,0.1C倍率下,其首次放电比容量接近理论值,达到117.3mAh/g,50次循环后容量保持率为97.3%。2C倍率下,其放电容量仍能达到81.6mAh/g,循环10次后容量未见衰减。     

基于咔唑和噻吩的2种聚合物的电化学性能

利用斯蒂尔偶联反应合成了2种基于咔唑和噻吩的有机共轭单体,通过电化学方法聚合成导电聚合物,并对其进行了结构表征和电化学性能研究。核磁共振1H谱和13C谱验证了单体与理论结构一致,红外测试验证了电化学聚合位点为噻吩的α位。在-0.1 V到1.2 V电压范围内,2种聚合物膜都表现出良好的电致变色特性。循环伏安法和热重表明,相比于聚合物P1,共平面性更好的聚合物P2的电化学和热稳定性更优。以上结论表明聚合物P2在电化学领域是一种更有前景的材料,单体结构差异对聚合物性能有很大影响。     

合成温度对Li2FeSiO4／C电化学性能的影响

采用球磨掺碳及固相法合成锂离子电池正极材料Li2FeSiO4/C,研究了合成温度对材料结构和电化学性能的影响.用X射线衍射(XRD)、扫描电镜(SEM)对材料的结构与形貌进行了表征;并对不同焙烧温度下合成的Li2FeSiO4/C材料的电化学性能进行了研究.结果表明,650℃合成的Li:FeSiO4/C电化学性能最佳,在C/16的倍率下首次放电容量达到144.8mAh/g,10次循环后容量仍保持有136.5mAh/g.     

水热合成时间对纳米MnO_2超电容性能的影响

以KMnO_4和MnSO_4·H_2O为原料,利用水热合成纳米MnO_2。采用X射线衍射(XRD)、场发射扫描电镜(SEM)、比表面积测试(BET)、循环伏安(CV)、恒流充放电以及交流阻抗(EIS)等方法研究水热合成时间对产物结构以及电化学性能的影响。结果表明水热合成为棒状纳米级α-MnO_2,随着水热合成时间增加,结晶度增加;水热合成纳米α-MnO_2在1 mol/L Na_2SO_4水溶液中具有良好的电化学电容性能,其中水热合成24 h制备棒状纳米MnO_2具有较高比电容,其真实电容量达到189 F/g;交流阻抗测试表明水热合成24 h制备的纳米MnO_2样品法拉第电荷传递能力和离子在电解液与活性材料界面的扩散能力得到提高,具有良好的电化学性能。     

非对称电化学电容器负极材料Li4Ti5O12的研究进展

Li4Ti5O12是一种尖晶石结构的可嵌锂材料,具有比能量高、循环性能稳定等特点,是电化学储能器件理想的电极材料.综述了Li4Ti5O12用作非对称电化学电容器电极材料的结构特点、储能原理、合成方法、电化学性能以及改性研究.针对Li4Ti5O12作为非对称电化学电容器负极材料大电流充放电时性能不佳的问题,提出了改进Li4Ti5O12电极材料电化学性能的研究思路.     

纳米SnO_2作为锂离子电池负极材料的研究进展

作为高比容量的锂离子电池负极材料,纳米SnO_2材料主要集中在形貌结构与电化学性能内在关系的研究。概述了低维度的SnO_2纳米线、纳米棒及高维度的多孔核-壳微球、多层中空纳米花等结构形貌的生长机理、合成方法及电化学性能,并对纳米SnO_2负极材料在锂离子电池的应用进行展望。     

锂离子电池正极材料的研制新进展

综述了锂离子电池正极材料的最近发展动态,着重介绍了被修饰的正极材料、O3-LiCoO2、LiFeO2的合成方法及电化学性能。展望了锂离子正极材料的发展趋势。     

锂离子电池正极材料层状LiMnO2的研究进展

对近年来圆外层状氧化锰锂正极材料的研究进展进行了综述。详细介绍了正交和单斜同质多晶层状氧化锰锂的晶体结构，合成方法及其电化学特性。开发新的合成方法以及多组分掺杂改性以提高英应用性仍是今后．层状氧化锰锂的研究发展方向。     

Nanoengineering Titania for High Rate Lithium Storage: A Review

Nanostructured titania have been intensively investigated as anode materials of Li-ion batteries for their excellent high rate performance. The size effects of TiO2 polymorphs (mainly rutile, anatase and TiO2-B) on their electrochemical performance and the latest efforts in nanoengineering titania anodes through enhancing their ionic or electronic transportation or both are reviewed in this work. We suppose that micron- or submicronsized porous structures assembled by TiO2 nanoparticles, nanowires/nanotubes or nanosheets with a high percentage of exposing high reactive facets together with a conductive percolating network are ideal anodes not only for high rate lithium storage but also for high packing densities of the active materials.     

非酶纳米电化学传感器用于有机磷农药残留物 检测综述

近年来,非酶纳米电化学传感器检测有机磷农药的研究受到广泛关注。非酶纳米电化学传感器具有检测成本低、操作方便、灵敏度高、响应快速等优点。碳纳米材料、纳米金属颗粒、纳米金属氧化物和纳米导电聚合物及其复合材料的出现,大大提高了有机磷农药电化学传感器的性能。随着纳米技术的出现,在合成纳米材料用于分析物特异性检测方面取得了进展,这些材料可用于构建高特异性、强选择性和经济有效的电化学传感器,以取代其他分析技术。鉴于各类纳米材料新结构的重要性,对非酶纳米电化学传感器领域的最新研究进展进行综述,并重点介绍纳米复合材料在有机磷农药检测中的应用。     

PEG-assisted electrochemical growth of lead oxide nanodendrites with strongly enhanced charge storage capacity

The shape-controlled synthesis of lead oxide nanodendrites (NDs) via electrochemical methods has been investigated in aqueous solution of PbNO₃ with the assistance of polyethylene glycole (PEG) as a soft template and its electrochemical performance on the lead acid battery electrodes was characterized by electrochemical impedance spectroscopy (EIS) technique. The morphology of the nanostructures mainly depends on the adjustable driving force of electrodeposition, such as the potential, the concentration of lead precursor (Pb²⁺), and the presence of inert electrolyte ions, while being modulated by PEG that contributes mainly to the finer structure in the shape-controlled synthesis. This unique structure provides an effective method for increasing the efficiency and capacity of the active material in lead-acid batteries.     

Ultrathin Two‐Dimensional Nanostructured Materials for Highly Efficient Water Oxidation

Water oxidation, also known as the oxygen evolution reaction (OER), is a crucial process in energy conversion and storage, especially in water electrolysis. The critical challenge of the electrochemical water splitting technology is to explore alternative precious‐metal‐free catalysts for the promotion of the kinetically sluggish OER. Recently, emerging two‐dimensional (2D) ultrathin materials with abundant accessible active sites and improved electrical conductivity provide an ideal platform for the synthesis of promising OER catalysts. This Review focuses on the most recent advances in ultrathin 2D nanostructured materials for enhanced electrochemical activity of the OER. The design, synthesis and performance of such ultrathin 2D nanomaterials‐based OER catalysts and their property‐structure relationships are discussed, providing valuable insights to the exploration of novel OER catalysts with high efficiency and low overpotential. The potential research directions are also proposed in the research field.     

Inlaying Ultrathin Bimetallic MOF Nanosheets into 3D Ordered Macroporous Hydroxide for Superior Electrocatalytic Oxygen Evolution

Controllable synthesis of ultrathin metal–organic framework (MOF) nanosheets and rational design of their nano/microstructures in favor of electrochemical catalysis is critical for their renewable energy applications. Herein, an in situ growth method is proposed to prepare the ultrathin NiFe MOF nanosheets with a thickness of 1.5 nm, which are vertically inlaid into a 3D ordered macroporous structure of NiFe hydroxide. The well‐designed composite delivers an efficient electrocatalytic performance with a low overpotential of 270 mV at a current density of 10 mA cm^?2 and stable electrolysis as long as 10 h toward the electrochemical oxygen evolution reaction, much superior to the state‐of‐the‐art RuO₂ electrocatalyst. A comprehensive analysis demonstrates that the excellent performance originates from the desirable combination of the highly exposed active centers in the ultrathin bimetallic MOF nanosheets, effective electron conduction between MOF nanosheets and ordered macroporous hydroxide, and efficient mass transfer across the hierarchically porous hybridization. This study sheds light on the exploration of powerful protocols to gain diverse high‐performance MOF nanosheets and may open a perspective to achieve their efficient electrocatalytic performance.     

硅元素掺杂改性尖晶石型锰酸锂的研究进展

尖晶石锰酸锂(LiMn₂O₄)具有理论比容量高、热稳定性高、价格低廉、循环性能良好等特点,深受研究者的亲睐,目前已有固相法、燃烧合成法和共沉淀等多种制备方法。为了进一步改善该材料的循环性能,研究者提出了元素掺杂的策略,元素掺杂改性是基于改变材料的晶体结构或材料中部分元素的平均价态来提高材料的电化学性能和结构的稳定性。Si⁴⁺掺杂可以取代材料中的部分Mn⁴⁺,从而使材料产生Jahn-Teller效应的离子数降低和尖晶石锰酸锂的八面体体积扩大,提高电化学性能。为此,综述了近几年来单一硅元素掺杂及硅与其他元素复合掺杂改性尖晶石型锰酸锂正极材料的研究进展。     

Nanospace‐Confinement Synthesis: Designing High‐Energy Anode Materials toward Ultrastable Lithium‐Ion Batteries

Exploiting high‐capacity and durable electrode materials is pivotal to developing lithium‐ion batteries (LIBs) and their applications. Multiscaled nanomaterials have been demonstrated to efficiently couple the advantages of each component on different scales in energy storage fields. However, the precise control of the microstructure remains a great challenge for maximizing their contributions. Nanospace‐confined synthesis provides a proactive strategy to build novel multiscaled nanomaterials with controllable internal void space for circumventing the intrinsic volume effects in the charge/discharge process. Herein, the rational design and synthesis of multiscaled high‐capacity anode materials are mainly summarized according to their electrochemical mechanisms by choosing 1D channel, 2D interlayer, and 3D space as representative confinement reaction environments. The structure–performance relationships are clarified with the assistance of quantitative calculations, molecular simulations, and so forth. Finally, future potentials and challenges of such a synthesis tactic in designing high‐performance electrode materials for next‐generation secondary batteries are outlooked.     

水热法制备尖晶石LiMn2O4正极材料的研究进展

介绍了近年来国内外有关水热法合成锂离子电池正极材料尖晶石LiMn2O4的研究工作,从锰源的选取对尖晶石锂锰氧化物的水热制备方法中存在的优缺点进行了比较和评述。对今后LiMn2O4水热合成研究以及发展方向等方面做了阐述。