二氯二甲基硅烷对锂硫电池性能的影响

采用二氯二甲基硅烷对锂片表面进行预处理,以提高电极的界面稳定性。将预处理的锂片与硫电极组装成锂硫电池,并对其进行充放电测试。结果表明,与以未经预处理锂片作负极的锂硫电池相比,经二氯二甲基硅烷预处理5 min的锂片作负极的锂硫电池的循环性能、倍率性能及库伦效率均得到较大的改善,且预处理时间对电池的性能有一定的影响。     

锂硫电池正极复合材料研究现状

锂硫电池由于其高理论能量密度(2600W·h/kg)而受到了广泛的关注,是极具应用前景的电池体系.硫基正极材料作为锂硫电池的重要组成部分,是提高电池性能的关键.然而锂硫电池还存在一些问题,如硫的利用率低及正极结构的稳定性差等.本文综述了近几年锂硫电池硫正极复合材料的研究现状,分别从硫/碳复合、硫/导电聚合物复合、硫/氧化物复合3个方面进行介绍,指出了未来锂硫电池正极材料要注意结合硫/导电聚合物及硫/氧化物的优势并注重材料结构的设计,向核壳或类核壳结构方向发展的趋势,同时还要提高载硫量,提高循环稳定性,以获得高性能的锂硫电池.     

功能性碳纳米管碳膜对锂硫电池性能影响的研究

锂硫电池由于其较高的理论能量密度近年来受到广泛关注。将海藻酸钠、聚乙烯醇、高比表面超导碳、碳纳米管制备成分散液,通过真空抽滤的方法制备了碳纳米管碳膜。将制备的碳膜置于锂硫电池正极与隔膜之间,以改善锂硫电池的性能。利用SEM,电化学性能测试等方法,表征了碳膜的微观形貌并测试了锂硫电池的电化学性能。引入碳膜的锂硫电池首次放电容量达到1537.6 m Ah/g,80次循环后容量保持在1189 m Ah/g。碳纳米管碳膜能够提供电子的传输通道,吸附聚硫离子,抑制固相产物在正极表面的富集,使锂硫电池的性能有较大幅度的提高。     

锂硫电池硫基碳正极材料及其改性研究进展

综述了锂硫电池存在的问题和碳纤维、碳纳米管、氧化石墨烯、多孔碳四种碳材料的性能以及其在锂硫电池正极中的应用,并探讨了碳材料原位掺杂非金属(C、N、O、B等)和复合各种金属化合物对材料的导电性和对多硫化物吸附性能的影响,以及对锂硫电池循环性能的影响。提出非金属掺杂多孔碳材料复合金属化物作为锂硫电池正极碳材料来降低多硫化物的穿梭效应以及反应过程中的体积膨胀,提高活性物质利用率,进而提高锂硫电池性能。     

碳基/硫复合材料用于锂-硫电池正极的研究

锂-硫电池得益于其高的理论比容量和能量密度,受到了很多科研人员的关注,它集绿色无污染、价格实惠、来源广阔等多种优点于一身,激发了专家学者的探索兴趣。其中锂-硫电池的正极材料是影响电池性能好坏的一个重要因素,现今碳材料的高导电性成为硫宿主材料的研究热点之一。本文主要介绍了几种碳基复合材料用于锂-硫电池的正极设计以及性能研究。     

一种水性多功能粘结剂对锂硫电池性能的影响（急）

以海藻酸钠(SA)与聚乙烯亚胺(PEI)为原料，制备了一种具有交联网络结构的海藻酸钠交联聚乙烯亚胺（SAPEI）多功能锂硫电池正极水性黏结剂。研究了SAPEI黏结剂的黏结性、多硫离子吸附能力，以及对锂硫电池正极结构和电化学性能的影响。结果表明，SAPEI黏结剂的黏结强度高于传统商用（PVDF）黏结剂，同时反应过程中产生的酰胺键对多硫离子具有吸附作用。使用SAPEI黏结剂的锂硫电池在循环后硫正极呈现出更加均匀的微观形貌结构和更优的电化学性能。在0.2 C倍率下充放电200次后其放电比容量仍然保持在620 mA·h/g，容量保持率可达到72.5％，高于使用PVDF黏结剂的锂硫电池。     

Li-S电池负极材料性能提升方法综述

硫和硫化物作为负极材料相较于商业化石墨电极具有更高理论比容量的优势,然而由于其"穿梭效应"和无限扩张的体积导致锂硫电池的性能低下。本文综述了目前一些研究方法,通过改变锂硫电池的形貌、多孔结构、催化剂等方向来提高锂硫电池的性能。     

锂硫电池硫/炭复合正极材料的研究进展

锂硫电池具有高比能量密度、原料丰富且对环境友好等优势,成为当前最具有吸引力的二次电池体系之一.然而循环寿命低制约着其商业化进程.本文主要综述了几十年来国内外学者在硫/炭复合正极材料方面的研究现状,并对未来新型正极材料的研究方向进行了展望.     

锂硫电池中抑制穿梭效应和锂枝晶的近期进展

锂硫电池具有突出的高比容量、环境友好、原材料廉价易得等特点,是未来新能源的一个选择方向。首先介绍了锂硫电池的研究背景以及放电原理,然后分别在电池的隔膜和负极2个方面叙述了抑制穿梭作用和抑制锂枝晶的最近进展,并且对未来锂硫电池的发展进行了展望。     

锂硫电池电解质的研究

文章综述了锂硫电池有机液态、凝胶聚合物和全固态电解质的研究进展;阐述了锂硫电池电解质现阶段研究工作中存在的问题,并展望了锂硫电池电解质未来的研究方向。     

适用于低温环境的动力锂离子电池研究进展

文章综述了锂离子电池负极,正极和电解液等影响动力电池低温性能的因素,为开发新一代适用于户外低温严酷环境条件下动力锂离子电池指明了方向。     

Effects of cathode impedance on the performances of power-oriented lithium ion batteries

Since power batteries have different requirements than traditional energy-oriented lithium ion batteries (LIBs) and their design concept is also different than energy-type cells, some new problems not encountered in energy-oriented LIBs must be carefully considered. This study illustrates that cathode impedance, a contributor to total cell impedance which can be ignored in the traditional energy-type LIBs, plays a very important role in power cells. This study uses 18650 cylindrical power cells consisting of a LiMn₂O₄ cathode and graphite anode with a basic electrolyte of PC/EC/DMC = 1/3/6 by weight containing 1.2 M LiPF₆ as model power LIBs. This study also investigates the charge–discharge performance of these model batteries made from cathodes with the same recipe but dried at different oven temperatures. The high impedance cathode produced under a high drying temperature causes the cell to fail during high-power applications. Cell heating during extreme high rate discharging periods not only causes pore closure in the porous separator, but also cathode peeling from the substrate. These phenomena, increasing the cell resistance and reducing the transfer rate of charged species, are believed to be the main causes for the poor cycle life of model batteries in high rate discharge tests.     

新型锂盐双乙二酸硼酸锂的制备与性能

文章综述了近年来锂离子电池豹新型锂盐一双乙二酸硼酸锂（LiBOB）研究的成果。介绍了双乙二酸硼酸锂的合成方法、组成与结构、化学和电化学性能及其与结构的关系。并重点综述了LiBOB电解液的导电性研究,对负极材料、正极材料的稳定性研究,与其他锂盐在锂离子电池中混合使用的性能研究等。总结了LiBOB的优缺点,指出了其进一步的研究方向。     

锂离子电池正极材料LiNi1/3Co1/3Mn1/3O2研究进展

层状结构材料LiNi1/3Co1/3Mn1/3O2具有高比容量、高循环性能、低成本和环保等优点,有望取代LiCoO2成为新一代锂离子电池正极材料。在介绍LiNi1/3Co1/3Mn1/3O2的结构特点和电化学反应特性的基础上,对其主要合成方法进行了详细评述,总结了该正极材料的阴阳离子掺杂、复合离子掺杂以及表面包覆改性等技术,指出国内外目前锂离子电池材料研究中存在的问题和未来的发展方向。     

Neutron depth profiling technique for studying aging in Li-ion batteries

During operation of a Li-ion cell, lithium diffuses in and out of the solid phase anode and cathode. Measuring the lithium concentration within the electrodes of the cell over its operational life could provide key information for understanding the loss of active lithium and the associated aging mechanisms. Concentration profiles of lithium in a cell are difficult to measure with traditional spectroscopic techniques. Here, neutron depth profiling was used to measure lithium near-surface concentration profiles along the anode and cathode strips in off-the-shelf cylindrical Li-ion batteries as a function of the aging process. A buildup of the surface concentration of lithium was found in graphite anode as well as a general decrease in the intercalation efficiency in lithium iron phosphate cathode material with aging.     

动力电池正极材料LiFePO_4的产业化应用展望

磷酸铁锂正极材料兼具安全性好、容量高且对环境友好等优点,成为目前最具潜力的动力电池正极材料之一。但其较低的电子导电率及离子电导率等缺点也十分明显。主要从磷酸铁锂正极材料本身的性能,包括倍率性能、能量密度、循环寿命和高低温性能方面分析了其实际应用于动力电池的潜力,以及结合国内外锂离子电池正极材料供应商情况简述了目前国内外磷酸铁锂产业化现状和趋势。     

In situ composite of nano SiO2-P(VDF-HFP) porous polymer electrolytes for Li-ion batteries

Nano SiO₂-P(VDF-HFP) composite porous membranes were prepared as the matrix of porous polymer electrolytes through in situ composite method based on hydrolysis of tetraethoxysilane and phase inversion. SEM, TEM, DSC and AC impedance analysis were carried out. It is found that the in situ prepared nano silica was homogeneously dispersed in the polymeric matrix, enhanced conductivity and electrochemical stability of porous polymer electrolytes, and improved the stability of the electrolytes against lithium metal electrodes. The in situ composite method was found to be much better than the direct composite method in lowering the interfacial resistance between electrolyte and lithium metal electrode. Moreover, cycle test of lithium batteries using lithium metal as anode and sulfur composite material as cathode showed that the electrolyte based on in situ composite of silica presented stable charge-discharge behavior and little capacity loss of battery.     

Hard carbon/lithium composite anode materials for Li-ion batteries

Hard carbon/lithium composite anode electrode is prepared to reduce the initial irreversible capacity of hard carbon, which hinders practical application of hard carbon in lithium ion batteries, by introducing lithium into hard carbon. Lithium foil effectively compensates the irreversible capacity of hard carbon in the first cycle. A full cell using LiCoO₂ cathode and the composite anode shows much higher initial coulombic efficiency than that of a cell using LiCoO₂ cathode and hard carbon anode. This paves the way to reduce the large initial irreversible capacity of hard carbon. Besides that, this composite anode enables conductive polymer/sulfur composite cathode to be used in Li-ion batteries with non-lithiated anode materials.     

LiAlO2-coated LiNi0.8Co0.1Mn0.1O2 and chlorine-rich argyrodite enabling high-performance all-solid-state lithium batteries at suitable stack pressure

All-solid-state lithium batteries (ASSLBs), which are consisted of Li_5.5PS_4.5Cl_1.5 electrolyte, metal lithium anode and LiNi_0.8Mn_0.1Co_0.1O₂ (NCM811) cathode, are speculated as a promising next generation energy storage system. However, the unstable oxide cathode/sulfide-based electrolyte interface and the dendrite formation in sulfide electrolyte using the lithium metal anode hinder severely commercialization of the ASSLBs. In this work, the dendrite formation in sulfide electrolyte is investigated in lithium symmetric cell by varying the stack pressure (3, 6, 12, 24 MPa) during uniaxial pressing, and uniformly nanosized LiAlO₂ buffer layer was carefully coated on NCM811 electrode (LiAlO₂@NCM811) to improve the cathode/electrolyte interface stability. The result shows that lithium symmetrical cell has a steady voltage evolution over 400 h under 6 MPa stacking pressure, and the assembled LiAlO₂@NCM811/Li_5.5PS_4.5Cl_1.5/Li battery under the stack pressure of 6 MPa exhibits large initial discharge specific capacity and excellent cycling stability at 0.05 C and 25 °C. The feasibility of using the lithium metal anode in all-solid-state batteries (ASSBs) under suitable stack pressure combined with uniformly nanosized LiAlO₂ buffer layer coated on NCM811 electrode supply a facile and effective measures for constructing ASSLBs with high energy density and high safety.     

全固态锂离子电池的研究进展与挑战

全固态锂离子电池具有安全性高、电化学性能优异等优点,但存在电极与电解质界面相容性差、室温离子电导率低等问题。本文总结了以上问题产生的原因及解决方案。对于正极界面,可复合正极材料与固态电解质、构造三维多孔结构固态电解质或在界面处引入缓冲层。对于负极界面,可设计界面层、原位聚合生成固态电解质、构造固态电解质骨架或使用自愈合和弹性固态电解质。对于固态电解质自身,以聚氧化乙烯（PEO）固态聚合物电解质为例,可添加增塑剂、无机陶瓷填料或构造聚合物共混物与嵌段共聚物。最后,对今后的研究方向提出了建议：应注重优化电极/固态电解质界面层;探索锂离子传输机理;构建具有高离子电导率的固态电解质等。