锰氧化物的构造、合成及在锂离子二次电池正极材料的应用

锰氧化物通常以各种隧道构造、层状构造的化合物存在。这些锰氧化物作为锂离子二次电池正极材料显示了优越的电化学性质，其电气特性依据锰氧化物结晶构造和合成条件的不同而存在很大的差异。本文对于隧道状及层状锰氧化物的结晶构造、合成及其作为锂离子二次电池正极材料所显示的电气特性等进行了评述。     

基于稀土层状氢氧化物的荧光材料研究进展

稀土层状氢氧化物(LRHs)结合了层状化合物的结构特性和稀土离子的功能特性，代表了一类新的功能材料，在光电、催化以及生物医学等领域具有巨大的应用潜力。本文主要综述了LRHs的研究进展，包括Ln₂(OH)₅(A^x-)_1/x·nH₂O (251-LRHs)和Ln₂(OH)₄SO₄·nH₂O (241-LRHs)的可控合成、结构特征、阴离子交换、纳米片剥离，以及在发光领域的应用，重点关注251-LRHs晶体的尺寸和形貌调控及纳米片剥离，总结了LRHs及其煅烧衍生物(氧化物、含氧硫酸盐和硫氧化物)荧光粉、高取向透明薄膜、光学温度传感器的发光特性，展望了LRHs功能化设计的研究方向，以期为今后进一步开发LRHs新型功能材料提供参考。     

无机层状纳米功能材料的研究进展

无机层状纳米功能材料是一类具有特殊结构和性能的新型无机二维纳米材料,它是由层状双金属氢氧化物通过插层反应得到的一类新型功能材料,其层板化学组成和尺寸可根据需要进行调整并且可以进行组装,具有广阔的应用前景.综述了无机层状纳米功能材料的研究与应用现状.     

新型功能性层状材料的合成及应用

无机层状化合物是一类具有规整层状结构的化合物,其层板上骨架阳离子的可替代性以及层间离子的可交换性引起了研究者的广泛兴趣.通过调变层板骨架阳离子、表面负载活性物种、层间柱撑无机或有机基团合成了各种新型功能性层状材料,并在酸碱催化、光催化、环保以及医药等领域有着广泛的应用.详细介绍了近年来新型层状化合物的合成及应用进展.     

无机层状化合物及其应用述评

无机层状化合物及其层间改性产物具有广阔的应用前景。本文综述了层状化合物的最新研究进展 ,以及利用层间嵌入反应制备纳米复合材料的方法和应用。     

近5年问世的聚合物/无机物纳米复合材料的阻燃性

综述了近5年问世的无机纳米填料包括碳纳米管(CNT)、层状氧化石墨(LGO)、层状双氢氧化合物(LDH)、多面低聚硅倍半氧烷(PO SS)及纳米碳纤维(CNF)等的复合材料研究进展,重点在于这些材料阻燃性能的特点及与聚合物/层状硅酸盐纳米复合材料(PLSN)的比较,并给予实例阐明。     

单分散性硫族化合物半导体量子点的制备与表征

硫族半导体化合物大多具有直接能带结构,是良好的光电功能材料,其量子点具有典型的量子效应.介绍了单分散量子点的无机成核/有机包裹的合成方法,通过尺寸选择性沉淀可以得到单分散的量子点;TEM、XRDUV-Vis吸收谱对硫族量子点的表征.     

隧道构造锰氧化物合成及应用

隧道构造锰氧化物在比表面、离子交换性、稳定性及分子级的隧道空间等方面具有优异的性能,其在催化剂、锂锰二次电池正极材料及吸附剂等材料科学领域的应用研究越来越受到人们的关注.综述了国内外隧道构造锰氧化物合成及应用的研究进展.     

聚酰亚胺／无机纳米杂化材料制备方法EI北大核心CSCD

本发明提供了一种聚酰亚胺／无机纳米杂化材料制备方法,首先合成适用于聚酰亚胺的无机纳米粒子改性剂——亚胺环基硅烷;采用溶胶-凝胶法制备无机氧化物纳米粒子,在溶胶一凝胶反应过程中加入改性剂亚胺环基硅烷,得到有机-无机复合体纳米颗粒;将有机-无机复合体纳米颗粒均匀分散于聚酰胺酸溶液中,经过加热处理得到聚酰亚胺／无机纳米杂化材料。本发明的聚酰亚胺／无机纳米杂化材料制备方法解决了纳米粒子分散的难题,在聚酰亚胺／无机纳米杂化材料中纳米粒子分布均匀,不团聚,有利于其各项性能的充分发挥。     

从第13届国际插层化合物大会看插层化合物的最新发展趋势

2005年6月5日至9日在法国克莱蒙特-弗朗市（Clermont-Ferrand）召开了第13届国际插层化合物大会（13th International Symposium on Intercalation Compounds，ISIC13），来自23个国家的170余名学者参加了此次大会，其中国内的清华大学材料系、北京化工大学可控化学反应重点实验室、武汉理工大学材料学院等10名代表参加了该次大会。大会内容涵盖了插层化合物的合成工艺、胶体化学、材料结构与材料电磁性、电化学性能、纳米材料（包括纳米粒、纳米纤维、纳米复合材料）、插层化合物的自组装技术以及生物分子的插层化合物等七个议题，包括炭材料（富勒烯、石墨、碳纳米管），过渡金属硫族化合物、金属氢氧化物、陶瓷及改性陶瓷、层状金属氧化物及氢氧化物、沸石及磷酸盐和纳米复合材料等七类材料。     

层状二氧化锰制备及应用研究进展

对国内外层状二氧化锰的制备方法及相关锰氧化物的应用现状进行综述,详细总结层状二氧化锰主要的制备方法,如固相反应法、水热合成法、溶胶-凝胶法、液相氧化-还原法等,对层状二氧化锰在锂电池电极材料、阳离子交换材料、吸附材料及污染物处理材料等领域的应用进行概述,并对其未来的发展趋势进行展望。结果认为:层状二氧化锰的制备与使用仍是今后一段时间内重点发展对象。固相法是在实际生产和研究实验中应用最多的一种方法,而液相法则因低投入、低能耗、污染小,是值得大力发展和推广的制备工艺路线。制备技术的不断成熟将使层状二氧化锰具有更广阔的应用前景。     

锂离子电池正极材料的研究进展

综述了近年来发展起来的一些锂离子电池正极材料 ,主要包括嵌锂的层状LixMO2 结构和尖晶石型LixM2 O4 结构的过渡金属氧化物 (M =Co、Ni、Mn、Cr等 )。重点介绍了锂钴氧化物、锂镍氧化物、锂锰氧化物的性能、制备、结构以及改性方法等 ,并对纳米电极材料和其它正极材料的发展情况作了简介     

多孔锰氧化物材料的制备与性能研究进展

孔径从微孔到介孔的多孔锰氧化物材料有多种制备方法.不同的制备方法,材料的性能有所不同.多孔锰氧化物材料在可充锂电池、高级分离技术、化学传感、催化以及环保等领域有潜在的重要应用价值.综述了多孔锰氧化物材料在结构、制备和性能等方面的研究进展.     

层状结构正极材料的改性与研究

层状锂锰氧化物作为锂离子电池的正极材料，具有无毒、低成本、能量密度高等优点。综述了近年来锂离子电池层状正极材料的研究进展，主要讨论了层状锂锰氧化物掺杂改性对其结构和电化学性能的影响，以及多元复合材料LiMnxCoyNi1-x-yO2的结构特性、制备方法、各金属元素含量的变化对其电性能的影响。     

Controllable Synthesis of 2D Materials by Electrochemical Exfoliation for Energy Storage and Conversion Application

2D materials have captured much recent research interest in a broad range of areas, including electronics, biology, sensors, energy storage, and others. In particular, preparing 2D nanosheets with high quality and high yield is crucial for the important applications in energy storage and conversion. Compared with other prevailing synthetic strategies, the electrochemical exfoliation of layered starting materials is regarded as one of the most promising and convenient methods for the large-scale production of uniform 2D nanosheets. Here, recent developments in electrochemical delamination are reviewed, including protocols, categories, principles, and operating conditions. State-of-the-art methods for obtaining 2D materials with small numbers of layers—including graphene, black phosphorene, transition metal dichalcogenides and MXene—are also summarized and discussed in detail. The applications of electrochemically exfoliated 2D materials in energy storage and conversion are systematically reviewed. Drawing upon current progress, perspectives on emerging trends, existing challenges, and future research directions of electrochemical delamination are also offered.     

An analysis of interface delamination mechanisms in orthotropic and hybrid fiber-metal composite laminates

The onset and propagation of interlaminar defects is one of the main damage mechanisms in composite materials. This is even more the case when considering layered materials comprising metallic laminae (typically Aluminium) and FRP laminae. Propagation of delamination mainly depends on the initial crack extension and its loading mode.This work presents some results of a combined analytical-numerical-experimental study on the onset and propagation mechanisms regarding interlaminar defects. Two cases have been analysed in particular, the first consisting of a glass-fibre reinforced epoxy resin laminate, and the second consisting of a hybrid laminate where a lamina of aluminium is layered between FRP laminae.     

High failure resistance layered ceramics using crack bifurcation and interface delamination as reinforcement mechanisms

Layered ceramics designed with weak interfaces favour interface delamination, while laminates with strong interfaces show higher strength and enhanced mechanical reliability. In this paper, conditions are reviewed aiming to combine crack bifurcation and interface delamination mechanisms in a unique architecture to design layered ceramics with high failure resistance. Based on a bi-material theoretical approach supported by experiments it is found that interface delamination can be favoured if crack bifurcation occurs in the compressive layers with a low inclination angle. The thickness and stresses of the compressive layers are the key features to optimise the mechanical behaviour in layered ceramics.     

Spacing and failure mechanism of edge fracture in two-layered materials

The phenomenon of edge fractures is analyzed using a fracturing process approach. Such fractures often initiated from the free surface of layered materials, and often terminate at the interface that divides the fractured layer and the matrix layer, or continue to expand along the interface, or create a peel-crack. To understand better the pattern of fractures with different spacing and the fracture mechanism, a double-layer elastic model with the same material properties with a fractured overlying layer subjected to uniaxial tension is simulated firstly. The stress distribution between two adjacent fractures is periodically distributed as a function of the ratio of the fracture spacing to the thickness of the fractured layer (S/t ratio), and homogeneous and heterogeneous material properties are considered in the simulation. The simulation results show that both the stress distribution and the critical value of fracture spacing to layer thickness ratio are affected by material heterogeneity; the S/t ratio of heterogeneous material is much smaller and it is much easier to crack compared with the homogeneous materials. In particular, the fracture saturation mechanism is analyzed by stress state change. Then a numerical simulation is carried out to reveal the fracturing process from micro-fracture formation, propagation, coalescence, nucleation, fracture infilling, fracture saturation, termination, to interface delamination. A fitting curve of the relationship between strain and spacing to layer thickness radio is obtained. It is found that infilling fractures may grow near the bottom or the free surface of the fractured layer by coalescence of micro-fractures and flaws. We also find that fracture spacing in the case of interface delamination is greater than that without interface delamination. A study of stress transition between the two layers on fracture spacing in the fracture process is also carried out, with a focus on stress transfer mode.     

锂离子二次电池正极材料氧化锰锂的研究进展

综述了最近几年对于锂离子二次电池正极材料氧化锰锂的研究。研究的氧化锰锂材料主要有尖晶石结构的ＬｉＭＮ２Ｏ４、Ｌｉ４Ｍｎ５Ｏ９和Ｌｉ４Ｍｎ５Ｏ１２以及层状结构的ＬｉＭｎＯ２。对于ＬｉＭＮ２Ｏ４,通过引入适当的杂原子和采用新的溶胶－凝胶法制备复相 可以有效地克服Ｊａｈｎ－Ｔｅｌｌｅｒ效应所造成的容量衰减现象。Ｌｉ４Ｍｎ５Ｏ９display structure     

The effects of shear and near tip deformations on energy release rate and mode mixity of edge-cracked orthotropic layers

In this paper semi-analytical expressions are derived for the energy release rate and the stress intensity factors of edge-cracked homogeneous and orthotropic layers subject to arbitrary generalized end forces. The expressions are accurate for long and short cracks. Following the work of Li et al. [Li S, Wang J, Thouless MD. The effects of shear on delamination in layered materials. J Mech Phys Solids 2004;52(1):193-214] for isotropic bi-material layers, the derivation extends the method proposed by Suo [Suo ZG. Delamination specimens for orthotropic materials. J Appl Mech 1990;57(3):627-34] for axial forces and bending moments in order to include the contribution of the shear forces. The shear contribution to the fracture parameters depends on the shear deformations along the layer and the elastic near tip deformation of the material. Li et al. [Li S, Wang J, Thouless MD. The effects of shear on delamination in layered materials. J Mech Phys Solids 2004;52(1):193-214] derived semi-analytical expressions for the fracture parameters that depend on the crack tip stress resultants, the elastic constants and five numerically-determined constants globally describing the effect of shear. In this paper analogous constants are derived for orthotropic layers and defined by semi-analytical expressions that highlight their physical significance and allow separation of the different contributions. The derivation is based on the assumption that the near tip deformation can be described by means of relative rotations between the cross sections of the different sub-layers at the crack tip (root rotations). The root rotations depend linearly on the crack tip stress resultants through compliance coefficients that are derived numerically in the paper for a wide range of orthotropic materials. Applications to different mixed mode delamination and peeling problems, for which accurate two-dimensional finite element solutions can be found in the literature, highlight the accuracy of the proposed expressions.