LiNi0.8Co0.15Al0.05O2/石墨锂离子电池高荷电存储老化机理研究

高荷电存储寿命对锂离子电池的使用性能具有重要影响, 但是相关研究却较为缺乏。本研究通过高温加速实验, 研究了LiNi_0.8Co_0.15Al_0.05O₂(NCA)/石墨锂离子电池在55 ℃下的存储寿命, 分析了正负极材料在电池寿命终点时的电化学性能和界面变化。研究结果表明, 在55 ℃、高荷电状态下NCA/石墨锂离子电池的存储寿命约为90 d。在寿命终点时, 正负极活性材料的容量有一定下降, 但不是电池容量衰减的主要原因。界面分析表明, 存储后负极表面固体电解质界面(SEI)膜增长明显, 而正极表面固体电解质界面(PEI)膜无明显变化。SEI膜的增长主要是由于电解液溶剂和锂反应, 造成石墨内锂损失, 使电池内可循环锂减少, 这是NCA/石墨电池在存储过程中容量损失的主要原因。     

动力锂电正极材料市场展望

<正>新能源汽车产业已经成为国家战略性新兴产业,被给予支撑未来经济发展和实现汽车产业转型升级的厚望。锂离子电池是当前商业化动力电池中能量密度最高的电化学体系,因此锂离子电池成为目前新能源汽车用动力电池的主流。锂离子电池具有较长的循环寿命及使用寿命,安全性也在不断改善,同时锂离子电池已处于大规模生产阶段,成本不断下降。锂离子电池的核心材料是正极材料,直接     

锂离子电池Li2MSiO4系正极材料研究进展

硅酸盐体系锂离子电池材料是新一代高性能锂离子电池正极材料选择之一,是值得研发的先进电池材料。综述了锂离子电池Li2MSiO4(M=Fe,Mn)系列正极材料的国内外最新研究进展。重点对该系列正极材料的合成方法、结构特点及电化学性能进行了总结和探讨。     

动力电池高比能正极材料LiVPO4F的最新研究进展

聚阴离子LiVPO4F是一种放电电压高、比容量大、比能量高、安全性好、结构稳定、价格低廉的新型正极材料,在锂离子电池特别是动力电池中具有广阔的应用前景。本研究在简述锂离子电池正极材料发展现状的基础上,重点阐述了LiVPO4F的优势与特色以及合成制备、结构解析、性能改善和储能机理等研究进展,进而指出其未来的研究重点和开发方向。     

动力锂离子电池三元正极材料LiNi_(1-x-y)Co_xAl_yO_2研究进展

锂离子电池三元材料LiNi1-x-yCoxAlyO2(NCA)为目前已经工业化应用的比容量最高的正极材料,具有循环性能好、原材料丰富和成本较低等优势,是一种极具应用前景的锂离子动力电池正极材料。但是,目前各种方法很难制备出纯相结构的LiNi1-x-y CoxAlyO2材料,并且存在首次充放电效率不高、高温稳定性能较差、振实密度低等缺点,制约着该材料的进一步应用和发展。综述了国内外三元材料LiNi1-x-y CoxAlyO2的研究进展,重点介绍了制备方法以及掺杂、包覆和表面处理等改性研究方法,并展望了LiNi1-x-yCoxAlyO2材料的未来应用和发展方向。     

高电压尖晶石LiNi0.5Mn1.5O4正极材料的研究进展

尖晶石LiNi0.5Mn1.5O4锂离子电池正极材料具有高的放电电压,高的能量密度,优异的倍率性能和循环性能的优势,极有可能成为下一代的锂离子电池正极材料。阐述了锂离子电池正极材料5V尖晶石LiNi0.5Mn1.5O4的结构、主要制备方法,介绍了离子掺杂、表面包覆等提高材料结构稳定性,改善高温高倍率循环性能的改进手段,并简述了此材料的产业化现状,展望了发展前景。     

锂离子电池正极材料LiMn2O4的研究进展

具有尖晶石相的LiMn2O4因价格低、无毒、无环境污染、制备简单、研究较成熟,因此有着很好的应用前景,被看作最有可能成为新一代商用锂离子二次电池正极材料.由于LiMn2O4电化学循环稳定性能不好,表现在可逆容量衰减较大,尤其在高温下(>55℃)使用衰减更严重,从而限制了它的商业化应用.经过近十几年的研究,人们对其衰减机理有了比较清晰的了解,提出了造成容量衰减的几种可能原因如Jahn-Teller畸变效应、Mn2+在电解质中的溶解、出现稳定性较差的四方相以及电解质的分解等.通过掺杂、表面包覆、制备工艺的改进,人们已能制得循环稳定性能较好的尖晶相材料.本文结合我们研究小组的最新研究成果对锂离子二次电池正极材料LiMn2O4的最新研究进展进行综述和评论.     

锂离子电池产业链发展研究

<正>1前言现在俗称的"锂电池",准确的叫法是"锂离子电池",它主要依靠锂离子在正极和负极之间移动进行工作:充电时,锂离子从正极脱嵌,在电解液中游动穿过隔膜嵌入负极,负极处于富锂状态;放电时则相反。这个过程中的相关材料——正极材料、负极材料、电解液(液态电解质)和隔膜被称为"锂离子电池4大关键材料"。除此之外,制造锂离子电池所需的其他材料还有铝箔(粘接正极材料的载体)、铜箔(粘接负极材料的载体)、粘     

锂离子电池高镍三元正极材料LiNi0.8Co0.1Mn0.1O2的改性研究进展

高镍三元正极材料LiNi_0.8Co_0.1Mn_0.1O₂(NCM811)具有平台电位高、能量密度大、成本低等优点，在动力锂离子电池市场具有广阔的应用前景。然而，该材料存在阳离子混排、表面不稳定、热稳定性差等缺点，导致电池在使用过程中出现容量衰减快、循环性能差、安全性能低等问题，严重阻碍了其大规模应用综述了NCM811材料的结构特征、存在问题及改性研究进展，重点介绍了离子掺杂、表面包覆、结构设计等改性方法对其电化学性能的影响，并展望了其未来发展趋势和应用前景。     

4种正极材料对锂离子电池性能的影响及其发展趋势

锂离子电池正极材料是锂离子电池发展的关键.从4种正极材料的安全性能、循环性能、存在的问题等方面评述了正极材料对锂离子电池发展起的作用和未来的发展趋势,其中钴酸锂和镍酸锂将依然会占据着小型电池市场的地位,而锰酸锂和磷酸铁锂将会促进大型电池市场的发展.此外,纳米技术在动力电池上的应用也将给电池带来较好的应用前景.     

Functional materials for rechargeable batteries

There is an ever-growing demand for rechargeable batteries with reversible and efficient electrochemical energy storage and conversion. Rechargeable batteries cover applications in many fields, which include portable electronic consumer devices, electric vehicles, and large-scale electricity storage in smart or intelligent grids. The performance of rechargeable batteries depends essentially on the thermodynamics and kinetics of the electrochemical reactions involved in the components (i.e., the anode, cathode, electrolyte, and separator) of the cells. During the past decade, extensive efforts have been dedicated to developing advanced batteries with large capacity, high energy and power density, high safety, long cycle life, fast response, and low cost. Here, recent progress in functional materials applied in the currently prevailing rechargeable lithium-ion, nickel-metal hydride, lead acid, vanadium redox flow, and sodium-sulfur batteries is reviewed. The focus is on research activities toward the ionic, atomic, or molecular diffusion and transport; electron transfer; surface/interface structure optimization; the regulation of the electrochemical reactions; and the key materials and devices for rechargeable batteries.     

Electrochemical Aging Protocol Governed Capacity Losses and Structure Degradations in Layered LiNi0.8Co0.1Mn0.1O2 Oxides

The comparatively poor endurance of Ni-rich cathode materials restricts their application in high-energy lithium-ion batteries. A thorough understanding of the degradation characteristics of such materials under complex electrochemical aging protocols is required to further improve their reliability. In this work, the irreversible capacity losses of LiNi_0.8Mn_0.1Co_0.1O₂ under different electrochemical aging protocols are quantitatively evaluated via a well-designed experiment. In addition, it is discovered that the origin of irreversible capacity losses is highly related to electrochemical cycling parameters and can be divided into two types. Type I is heterogeneous degradation caused by low C-rate or high upper cut-off voltage cycling and features abundant capacity loss during H2-H3 phase transition. Such capacity loss is attributed to the irreversible surface phase transition that limits the accessible state of charge during the H2-H3 phase transition stage via the pinning effect. Type II is fast charging/discharging induced homogeneous capacity loss that occurs consistently throughout the whole phase transition time. This degradation pathway shows a distinctive surface crystal structure, which is dominated by a bending layered structure rather than a typical rock-salt phase structure. This work offers detailed insight into the failure mechanism of Ni-rich cathodes and provides guidance on designing long-cycle life, high-reliability electrode materials.     

Nanostructured electrodes for lithium-ion and lithium-air batteries: the latest developments, challenges, and perspectives

The urgency for clean and secure energy has stimulated a global resurgence in searching for advanced electrical energy storage systems. For now and the foreseeable future, batteries remain the most promising electrical energy storage systems for many applications, from portable electronics to emerging technologies such as electric vehicles and smart grids, by potentially offering significantly improved performance, energy efficiencies, reliability, and energy security while also permitting a drastic reduction in fuel consumption and emissions. The energy and power storage characteristics of batteries critically impact the commercial viability of these emerging technologies. For example, the realization of electric vehicles hinges on the availability of batteries with significantly improved energy and power density, durability, and reduced cost. Further, the design, performance, portability, and innovation of many portable electronics are limited severely by the size, power, and cycle life of the existing batteries. Creation of nanostructured electrode materials represents one of the most attractive strategies to dramatically enhance battery performance, including capacity, rate capability, cycling life, and safety. This review aims at providing the reader with an understanding of the critical scientific challenges facing the development of advanced batteries, various unique attributes of nanostructures or nano-architectures applicable to lithium-ion and lithium-air batteries, the latest developments in novel synthesis and fabrication procedures, the unique capabilities of some powerful, in situ characterization techniques vital to unraveling the mechanisms of charge and mass transport processes associated with battery performance, and the outlook for future-generation batteries that exploit nanoscale materials for significantly improved performance to meet the ever-increasing demands of emerging technologies.     

High rate performances of the cathode material LiNi1/3Co1/3Mn1/3O2 synthesized using low temperature hydroxide precipitation

A low-temperature reaction route is introduced based on hydroxide precipitation method to synthesize the cathode material LiNi_1/3Co_1/3Mn_1/3O₂. The crystal structure and morphology of the prepared powder have been characterized by X-ray diffraction and Scan electron microscope, respectively. The charge–discharge tests were performed between 2.5 and 4.5 V. The discharge capacity of the material is strongly impacted by the reaction temperature. The powders sintered at 850 °C show the best electrochemical performance and the initial discharge capacity is about 160 mAh g⁻¹ at 5 C. Powder X-ray diffraction and Scan electron microscope results reveal that the excellent electrochemical performances should be ascribed to the lower precursor reaction temperature, the lower degree of cation mixing and analogous spherical small particles, which can improve the transfer of Li ions and electrons. All these results indicate that this material has potential application in lithium-ion batteries.     

无机固体电解质Li7La3Zr2O12的制备及掺杂改性研究进展

无机固体电解质由于其安全性能高、能量密度大等特点备受研究者的青睐。其中Garnet型锂离子无机固体电解质Li_7La_3Zr_2O_(12)具有较高的离子导电率,较低的界面电阻,优良的稳定性能和电化学性能,在未来的全固态锂离子电池、锂空气电池等领域有着广阔的应用前景。主要从Li_7La_3Zr_2O_(12)的晶体结构、制备工艺和掺杂改性等方面详细阐述无机固态电解质Li_7La_3Zr_2O_(12)的研究进展。     

Layer-by-layer assembly synthesis of ZnO/SnO2 composite nanowire arrays as high-performance anode for lithium-ion batteries

A layer-by-layer approach has been developed to synthesize ZnO/SnO₂ composite nanowire arrays on copper substrate. ZnO nanowire arrays have been first prepared on copper substrate through seed-assisted method, and then, the surface of ZnO nanowires have been modified by the polyelectrolyte. After oxidation-reduction reaction, SnO₂ layer has been deposited onto the surface of ZnO nanowires. The as-synthesized ZnO/SnO₂ composite nanowire arrays have been applied as anode for lithium-ion batteries, which show high reversible capacity and good cycling stability compared to pure ZnO nanowire arrays and SnO₂ nanoparticles. It is believed that the improved performance may be attributed to the high capacity of SnO₂ and the good cycling stability of the array structure on current collector.     

Synthesis and electrochemical properties of Co3O4 nanofibers as anode materials for lithium-ion batteries

Co₃O₄ nanofibers as anode materials for lithium-ion batteries were prepared from sol precursors by using electrospinning. The morphology, structure and electrochemical properties of Co₃O₄ nanofibers were characterized by atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and charge-discharge experiments. The results show that Co₃O₄ nanofibers possessed typical spinel structure with average diameter of 200 nm. The initial capacity of Co₃O₄ nanofibers was 1336 mAhg^− 1 and the capacity reached 604 mAhg^− 1 up to 40 cycles. It was suggested that the high reversible capacity could be ascribed to the high surface area offered by the nanofibers' structure.     

Focus on Spinel Li4Ti5O12 as Insertion Type Anode for High‐Performance Na‐Ion Batteries

Sodium‐ion batteries (SIBs) toward large‐scale energy storage applications has fascinated researchers in recent years owing to the low cost, environmental friendliness, and inestimable abundance. The similar chemical and electrochemical properties of sodium and lithium make sodium an easy substitute for lithium in lithium‐ion batteries. However, the main issues of limited cycle life, low energy density, and poor power density hamper the commercialization process. In the last few years, the development of electrode materials for SIBs has been dedicated to improving sodium storage capacities, high energy density, and long cycle life. The insertion type spinel Li₄Ti₅O₁₂ (LTO) possesses “zero‐strain” behavior that offers the best cycle life performance among all reported oxide‐based anodes, displaying a capacity of 155 mAh g^?1 via a three‐phase separation mechanism, and competing for future topmost high energy anode for SIBs. Recent reports offer improvement of overall electrode performance through carbon coating, doping, composites with metal oxides, and surface modification techniques, etc. Further, LTO anode with its structure and properties for SIBs is described and effective methods to improve the LTO performance are discussed in both half‐cell and practical configuration, i.e., full‐cell, along with future perspectives and solutions to promote its use.     

Rutile TiO2 nanorod arrays directly grown on Ti foil substrates towards lithium-ion micro-batteries

Nanosized rutile TiO₂ is one of the most promising candidates for anode material in lithium-ion micro-batteries owing to their smaller dimension in ab-plane resulting in an enhanced performance for area capacity. However, few reports have yet emerged up to date of rutile TiO₂ nanorod arrays growing along c-axis for Li-ion battery electrode application. In this study, single-crystalline rutile TiO₂ nanorod arrays growing directly on Ti foil substrates have been fabricated using a template-free method. These nanorods can significantly improve the electrochemical performance of rutile TiO₂ in Li-ion batteries. The capacity increase is about 10 times in comparison with rutile TiO₂ compact layer.     

A hierarchical Ti2Nb10O29 composite electrode for high-power lithium-ion batteries and capacitors

Ti₂Nb₁₀O₂₉ (TNO) is a suitable electrode for high-performance lithium-ion batteries and capacitors because of its large lithium storage capacity and high Li⁺ diffusivity. Currently, the rate or power capability of TNO-based systems is limited by the poor electronic conductivity of the material. Here we report our findings in design, synthesis, and characterization of a hierarchical N-rich carbon conductive layer wrapped TNO structure (TNO@NC) using a novel polypyrrole-chemical vapor deposition (PPy-CVD) process. It was found that carbon coating with PPy–carbon partially reduces Ti and Nb cations, forms TiN, and creates oxygen vacancies in the TNO@NC structure that further increase overall electronic and ionic conductivity. Various defect models and density functional theory (DFT) calculations are used to show how oxygen vacancies influence the electronic structure and Li-ion diffusion energy of the TNO@NC composite. The optimized TNO@NC sample shows notable rate capability in half-cells with a reversible capacity of 300 mAh g⁻¹ at 1 C rate and maintains 211 mAh g⁻¹ at a rate of 100 C, which is superior to that of most M_xNb_yO_z materials. Full cell LiNi_0.5Mn_1.5O₄ (LNMO)||TNO@NC lithium-ion batteries (LIB) and active carbon (AC)||TNO@NC hybrid lithium-ion capacitors (LIC) exhibited notable volumetric and gravimetric energy and power densities.