Insight into effects of graphene and zinc oxide in Li4Ti5O12 as anode materials for Li-ion full-cell battery

Programmable design of nanocomposites of Li₄Ti₅O₁₂ (LTO) conducted through hydrothermal route in the presence of ethylenediamine as basic and capping agent. In this work, effect of ZnO and Graphene on the Li₄Ti₅O₁₂ based nanocomposites as anode materials investigated for Li-Ion battery performances. The full cells battery assembled with LTO based nanocomposites on Cu foil as the anode electrode and commercial LMO (LiMn₂O₄) on aluminum foil as cathode electrode. X-Ray diffraction (XRD), Energy-dispersive X-ray spectroscopy (EDS), Fourier-transform infrared spectroscopy (FT-IR), along with Field Emission Scanning Electron Microscopy (FE-SEM) and Transmission electron microscopy (TEM) images was applied for study the composition and structure of as-prepared samples. The electrochemical lithium storage capacity of prepared nanocomposites was compared with pristine LTO via chronopotentiometry charge-discharge techniques at 1.5–4.0 V and current rate of 100 mA/g. As a result, the electrode which is provided by LTO/TiO₂/ZnO and LTO/TiO₂/graphene nanocomposites provided 765 and 670 mAh/g discharge capacity compared with pristine LTO/TiO₂ (550 mAh/g) after 15 cycles. Based on the obtained results, fabricated nanocomposites can be promising compounds to improve the electrochemical performance of lithium storage.     

Analysis and improvement of high temperature floating charge performance for high voltage lithium ion batteries

为研究高电压体系锂离子电池浮充性能的影响因素,对浮充失效电池的产气成分、正负极材料的结构变化、金属溶出情况、隔膜形貌及Gurley值变化等进行了深入分析研究,结果表明：电池在长时间高温浮充过程中,正极材料发生相变,金属元素溶出,同时释放O₂造成电解液的氧化分解;高温高电压状态下负极SEI膜也会破坏,并发生不断的重整及修复反应,这些反应产物沉积到负极表面及隔膜孔隙内,导致靠近负极侧的隔膜孔隙堵塞甚至贯穿,即引起正负极微短路,释放出大量气体。通过提高正极材料的结构稳定性、优化电解液形成稳定的CEI和SEI,改善增加隔膜的穿刺强度都能明显改善电池的高温浮充性能。     

TiF3 catalyzed MgH2 as a Li/Na ion battery anode

MgH₂ has been considered as a potential anode material for Li ion batteries due to its low cost and high theoretical capacity. However, it suffers from low electronic conductivity and slow kinetics for hydrogen sorption at room temperature that results in poor reversibility, cycling stability and rate capability for Li ion storage. This work presents a MgH₂–TiF₃@CNT based Li ion battery anode manufactured via a conventional slurry based method. Working with a liquid electrolyte at room temperature, it achieves a high capacity retention of 543 mAh g^?1 in 70 cycles at 0.2 C and an improved rate capability, thanks to the improved hydrogen sorption kinetics with the presence of catalytic TiF₃. Meanwhile, the first realization of Na ion uptake in MgH₂ has been evidenced in experiments.     

The degradation analysis of lithium-ion storage battery with Li4Ti5O12 anode

钛酸锂作为储能电池负极材料,在长循环和安全性上有突出的表现。通过对室温1C和2C倍率下循环的三元+钴酸锂/钛酸锂储能电池拆解,结合SEM、FTIR、XRD和EIS等分析手段,发现造成容量衰减和阻抗增大的原因出现在正极,由于正极与电解液发生反应,在表面生成界面膜,并且循环过程中界面膜不稳定,进一步消耗活性锂离子导致。另外,对这款电池的产气分析发现,所产生气体的主要成分为CO2和C2H6,原因可能是在制备电池过程中严格控制水分以及在电解液添加剂方面做了改进。     

有机溶剂浸泡法回收再利用锂离子电池钛酸锂负极材料

利用有机溶剂法回收了废旧锂离子电池中的钛酸锂负极材料,并对回收的钛酸锂材料的结构、形貌和电化学性能进行了测试。XRD结果表明,材料除炭后添加适量锂源进一步合成得到的产物具有尖晶石结构,且不含其他的杂质。SEM图像显示,其颗粒分布均匀、无团聚现象。EIS结果表明,最终回收的钛酸锂电极材料比未添加锂源进行煅烧处理的材料具有较小的电荷转移阻抗和较高的锂离子扩散系数。在0.1 C倍率下,经过100次循环后其容量保持率为92.4%,具有优异的循环稳定性和可逆性,可以实现循环利用。     

Electrochemistry and safety of Li4Ti5O12 and graphite anodes paired with LiMn2O4 for hybrid electric vehicle Li-ion battery applications

A promising anode material for hybrid electric vehicles (HEVs) is Li₄Ti₅O₁₂ (LTO). LTO intercalates lithium at a voltage of ∼1.5 V relative to lithium metal, and thus this material has a lower energy compared to a graphite anode for a given cathode material. However, LTO has promising safety and cycle life characteristics relative to graphite anodes. Herein, we describe electrochemical and safety characterizations of LTO and graphite anodes paired with LiMn₂O₄ cathodes in pouch cells. The LTO anode outperformed graphite with regards to capacity retention on extended cycling, pulsing impedance, and calendar life and was found to be more stable to thermal abuse from analysis of gases generated at elevated temperatures and calorimetric data. The safety, calendar life, and pulsing performance of LTO make it an attractive alternative to graphite for high power automotive applications, in particular when paired with LiMn₂O₄ cathode materials.     

Facile controlled synthesis of hierarchically structured mesoporous Li4Ti5O12/C/rGO composites as high-performance anode of lithium-ion batteries

In this paper, a facile strategy is proposed to controllably synthesize mesoporous Li₄Ti₅O₁₂/C nanocomposite embedded in graphene matrix as lithium-ion battery anode via the co-assembly of Li₄Ti₅O₁₂ (LTO) precursor, GO, and phenolic resin. The obtained composites, which consists of a LTO core, a phenolic-resin-based carbon shell, and a porous frame constructed by rGO, can be denoted as LTO/C/rGO and presents a hierarchical structure. Owing to the advantages of the hierarchical structure, including a high surface area and a high electric conductivity, the mesoporous LTO/C/rGO composite exhibits a greatly improved rate capability as the anode material in contrast to the conventional LTO electrode.     

Analysis of cycling performance failure of NMC811/SiO-C pouch cells with high specific energy

NMC811/SiO-C电池由于电极材料克容量高,工作平台电压高成为实现高比能量密度的一个重要途径,然而在实际应用中其循环寿命差的问题一直难以解决。本工作通过电化学阻抗谱（EIS）、X射线衍射光谱、傅里叶红外变换光谱（FTIR）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）等多种分析表征手段对循环前后电极材料进行了表征测试与分析,系统研究了NMC811/SiO-C电池长期循环失效的原因,结果表明：NMC811正极材料在循环过程中结构保持完整,金属溶出现象轻微;而SiO-C负极材料在循环过程中膨胀粉化,并且不断消耗电解液和形成更厚的SEI膜,最终导致负极克容量衰减严重,是全电池常温循环性能很差的主要原因。     

Low temperature thermal safety performance of soft packaged lithium iron phosphate battery

本文以剩余容量接近80%的软包磷酸铁锂电池为研究对象,研究其在-10 ℃低温充放电循环后的安全性能.对低温和常温循环后的电池进行热失控实验分析,同时解剖电池并测试电池材料的锂元素含量和热稳定性能.测试结果表明,电池低温循环过程中容量急剧衰减,低温循环后电池热失控温度明显降低,低温循环过程中电池负极析出了锂单质,电池材料的热稳定性也发生了变化.另外,还对低温循环后的电池进行了满电状态下的常温搁置实验,实验过程中电池全部产生胀气现象,通过进一步测试分析发现,气体以CO和H₂为主.与新电池对比发现,剩余容量接近80%的软包磷酸铁锂电池低温下充放电循环更容易产生锂枝晶,造成其电化学性能发生严重的不可逆衰退,热失控温度明显提前,因此剩余容量接近80%的磷酸铁锂电池应避免在低温下运行.     

Simulation of capacity loss in carbon electrode for lithium-ion cells during storage

A mathematical model was developed which simulates the self-discharge capacity losses in the carbon anode for a SONY 18650 lithium-ion battery. The model determines the capacity loss during storage on the basis of a continuous reduction of organic solvent and de-intercalation of lithium at the carbon/electrolyte interface. The state of charge, open circuit potential, capacity loss and film resistance on the carbon electrode were calculated as a function of storage time using different values of rate constant governing the solvent reduction reaction.     

Graphite materials prepared by HTT of unburned carbon from coal combustion fly ashes: Performance as anodes in lithium-ion batteries

The behaviour as the potential negative electrode in lithium-ion batteries of graphite-like materials that were prepared by high temperature treatment of unburned carbon concentrates from coal combustion fly ashes was investigated by galvanostatic cycling. Emphasis was placed on the relation between the structural/morphological and electrochemical characteristics of the materials. In addition, since good electrode capacity retention on cycling is an important requirement for the manufacturing of the lithium-ion batteries, the reversible capacity provided by the materials prepared on prolonged cycling (50 cycles) was studied and the results were compared with those of petroleum-based graphite which is commercialized as anodic material for lithium-ion batteries. The graphite-like materials prepared lead to battery reversible capacities up to ∼310 mA hg⁻¹ after 50 cycles, these values were similar to those of the reference graphite. Moreover, they showed a remarkable stable capacity along cycling and low irreversible capacity. Apparently, both the high degree of crystallinity and the irregular particle shape with no flakes appear to contribute to the good anodic performance in lithium-ion batteries of these materials, thus making feasible their utilization to this end.     

Recent research progress of Li4Ti5O12 as anode materials for lithium-ion batteries

锂离子电池凭借诸多优势广泛应用于便携式电子产品（3C）领域,在电动汽车及可穿戴设备方面具有巨大应用前景,是未来最具潜力的储能电池之一。作为一种锂离子电池负极材料,尖晶石型Li₄Ti₅O₁₂相比石墨负极具有较高嵌锂电位,且"零应变材料"的特性决定Li₄Ti₅O₁₂材料具有较好的循环稳定性及热稳定性,从而备受关注。本文简要介绍了钛酸锂（Li₄Ti₅O₁₂）的结构和性能,详细阐明了Li₄Ti₅O₁₂的嵌锂机制、制备及改性方法,总结了相应制备及改性方法对Li₄Ti₅O₁₂材料的充放电特性、循环性能等电化学性能的影响,针对Li₄Ti₅O₁₂的胀气产生原因、机制和胀气解决方法进行简单阐述,并对纯电动乘用车的应用前景提出了几点建议。     

铜基底上无黏结剂Co3V2O8多孔纳米片阵列的制备以及锂离子电池性能研究

直接在铜基底上生长具有不同金属离子的多孔过渡金属氧化物,成为有前途的锂离子电池电极材料的候选。本文提出了一种简便可行的低温水热沉积方法在铜基底上制备前驱物阵列。前驱物经过煅烧处理得到具有多孔特性Co₃V₂O₈纳米片阵列,多孔纳米片阵列用作锂离子电池负极材料显示出了长期循环稳定性和高倍率性能。在1.0 A/g电流密度下,电池经过240次循环后显示出1 010 mA∙h/g的容量;在3.0 A/g的电流密度下,电池循环600次后显示出552 mA∙h/g的可逆容量。     

Effect and mechanism study on buffer layer in secondary Li metal battery

锂金属是已知的理论比容量（3860 mA·h/g）最高的材料,且锂金属具有最低的对氢电位（-3.040 V）和极小的密度（0.53 g/cm³）。所以锂金属是一种极具潜力的电池负极材料。但是锂金属电池存在着很严重的安全问题且循环效率低,所以直到现在还没有正式商用。锂离子电池的发展日趋成熟,但是其容量已经无法满足科技的发展,所以发展下一代电池刻不容缓,而锂金属电池是一个良好的选择。为了克服锂金属负极在应用中存在的问题,本文提出了一种缓冲层结构插入锂金属电池的隔膜与负极之间,并分别将碳纳米管和聚苯胺/碳纳米管复合材料作为缓冲层插入锂电池中。倍率性能测试、循环性能测试和形貌测试均指出,缓冲层结构对锂金属负极的枝晶生长具有抑制作用,从而改善了锂金属电池的安全问题,并对其循环效率具有很大的提升作用。     

Study of the charging process of a LiCoO2-based Li-ion battery

A three-electrode Li-ion cell with metallic lithium as the reference electrode was designed to study the charging process of Li-ion cells. The cell was connected to three independent testing channels, of which two channels shared the same lithium reference to measure the potentials of anode and cathode, respectively. A graphite/LiCoO₂ cell with a C/A ratio, i.e., the reversible capacity ratio of the cathode to anode, of 0.985 was assembled and cycled using a normal constant-current/constant-voltage (CC/CV) charging procedure, during which the potentials of the anode and cathode were recorded. The results showed that lithium plating occurred under most of the charging conditions, especially at high currents and at low temperatures. Even in the region of CC charging, the potential of the graphite might drop below 0 V versus Li⁺/Li. As a result, lithium plating and re-intercalating of the plated lithium into the graphite coexist, which resulted in a low charging capacity. When the current exceeded a certain level (0.4C in the present case), increasing the current could not shorten the charging time significantly, instead it aggravated lithium plating and prolonged the CV charging time. In addition, we found that lowering the battery temperature significantly aggravated lithium plating. At −20 °C, for example, the CC charging became impossible and lithium plating accompanied the entire charging process. For an improved charging performance, an optimized C/A ratio of 0.85–0.90 is proposed for the graphite/LiCoO₂ Li-ion cell. A high C/A ratio results in lithium plating onto the anode, while a low ratio results in overcharge of the cathode.     

Reviews of selected 100 recent papers for lithium batteries (Feb. 1, 2019 to Mar. 31, 2019)

该文是一篇近两个月的锂电池文献评述,以“lithium”和“batter^*”为关键词检索了Web of Science从2019年2月1日至2019年3月31日上线的锂电池研究论文,共有2208篇,选择其中100篇加以评论。正极材料主要研究了层状材料的结构演变及表面包覆对层状和尖晶石材料的影响。硅基复合负极材料研究侧重于嵌脱锂机理以及SEI界面层,金属锂负极的研究侧重于通过集流体、三维电极和表面覆盖层的设计以及电解液添加剂来提高其循环性能,并与锂硫和固态电池应用结合研究。固态电解质侧重于制备方法和离子输运机理研究,电解液添加剂的研究目标是提高电池充电至高电压时的稳定性。全固态电池的重点在于电极和电池设计和工艺研究。除了以材料为主的研究之外,针对电池分析、理论模拟和电池模型的研究论文也有多篇。     

Recent progress of electrode materials for room-temperature sodium-ion stationary batteries

随着风能、太阳能等可再生能源的不断发展,储能作为影响其发展的关键技术越来越受到人们的关注。在储能领域,锂离子电池以高能量密度、长循环寿命、高电压等诸多优点在电子领域已得到广泛的应用,并成为未来电动汽车动力电池的最佳选择。但因锂资源储量有限、分布不均匀,而且原材料成本比较高,所以锂离子电池在电网大规模储能方面的应用遇到了瓶颈。与锂相比,钠不但具有与锂相似的物理化学性质,更具有资源丰富、分布广泛、原料成本低廉等优势。近些年室温钠离子电池再次引起了人们的研究兴趣,特别是在电网储能方面表现出极大的应用潜力。虽然目前已报道了多种钠离子电池电极材料,但大都离实用化以及进一步产业化尚有一定的距离。本文重点介绍一些性能较为突出的室温钠离子电池电极材料,并指出要实现钠离子电池的产业化,需要开发空气中稳定、高安全、高容量、高倍率、循环稳定、低成本的新型正、负极材料。     

Nanocone-arrays supported tin-based anode materials for lithium-ion battery

The electrodeposited nickel nanocone-arrays without any template are introduced to Sn-based anode materials as current collector for lithium ion battery. Nickel nanocone-arrays are tightly wedged in the electrodeposited Sn film, and thereby enhance the interfacial strength between active materials and substrate. Furthermore, annealing is conducted to form Sn-Ni alloy, in which Ni renders an inactive matrix to buffer volume change during cyclic lithiation/delithiation. The nanocone-arrays supported Sn-Ni alloy anode shows satisfactory Li⁺ storage properties with the first reversible capacity of 807 mAh g⁻¹. The charge capacity for the 50th cycle is 678 mAh g⁻¹, delivering good retention rate of 99.6% per cycle. These improved performances of nickel nanocone-arrays supported Sn-Ni alloy anodes indicate the potential of their application as electrode materials for high performance energy storage.     

Experimental research on temperature rise and electric characteristics of aluminum air battery under open‐circuit condition for new energy vehicle

Due to lack of systematic research on open‐circuit voltage (OCV) and electrolyte temperature rise characteristics of aluminum air battery, in order to explore the influential factors on the OCV and electrolyte temperature rise of aluminum air battery, in this paper, for the first time, we studied the effects of different ambient temperature conditions, different concentrations of NaOH and KOH electrolyte, and pure aluminum and aluminum alloy on the OCV and electrolyte temperature rise of aluminum air battery. Results show that the OCV of aluminum air battery is obviously affected by ambient temperature conditions, electrolyte concentration, and different anode materials. The OCV range is 1.5 to 1.8 V at 0°C under different KOH‐electrolyte concentrations when aluminum alloy is used as anode material; with the increase of ambient temperature, the OCV will rise, and the range is 1.8 to 1.95 V. The working process of aluminum air battery is accompanied by the phenomenon of heat release, and the temperature rise range of electrolyte will not exceed 7°C when aluminum alloy is used as the anode material; however, the highest temperature of the electrolyte can reach 100°C when pure aluminum is used as the negative electrode material. The results of this study will provide theoretical guidance for designing aluminum air batteries and identifying their optimal operating conditions.     

A novel flower-like metal-based oxides with cross-linked networks for rapid lithium-ion storage

A cross-linked MnO₂ coated ZnFe₂O₄ hollow nanosphere composite is synthesized and controlled via a facial and handy route. The connected MnO₂ nanoplates form a cross-linked network, which is conducive to the rapid transfer of Li ions. The composite with unique architecture can not only release the strain and stress caused by the insertion and desertion of lithium ions but also greatly improve the electrical conductivity and lithium ion diffusivity. Consequently, when used as a lithium-ion battery anode material, the electrode shows an excellent initial reversible capacity of 933.5 mAh/g with an initial coulombic efficiency of 62.5%. After 100 cycles, the reversible capacity stabilized at 605.6 mAh/g with a high capacity retention of 91% from the 20th cycle to the 100th cycle. At a high current density of 3 A/g, an excellent capacity of 390.6 mAh/g can be retained. In this case, the electrode shows broad application prospects for novel power storage systems.