负极材料Li4-xMg-Ti5-yCoyO12的合成及其电化学性能

以Mg(CH3 COO)2·4H2O,CO(CH3 COO)2-4H2O作为Mg2+和CO2+的掺杂源,以乙醇为溶剂,C6H15 NO3作为络合剂,CH3,COOLi·2H2O和Ti(OC4 H9)4作为原料,利用溶胶-凝胶法制备复合掺杂2种金属的Li4-xMg-Ti5-yCoyO12材料,并对其进行了X射线衍射(XR...     

二次锂离子电池负极材料Li4Ti5O12的研究进展

Li4Ti5O12由于其长的循环寿命及高的安全性能,成为二次锂离子电池,特别是动力电池的优秀候选材料.本文综述了负极材料Li4Ti5O12的结构、合成方法、物理特性和电化学性能,着重介绍了各种元素的掺杂对Li4Ti5O12循环容量、充放电电压平台及高倍率性能的影响.     

锂离子电池负极材料Li4Ti5O12的研究进展

Li4Ti5O12作为锂离子电池的负极材料, 在Li 嵌入和脱出的过程中,其晶型不发生改变,被称之为“零应变材料”。因而具有优良的循环性能和平稳的放电电压,能够避免电解液分解现象或保护膜的生成,安全性和可靠性得以大大改善。详细描述了Li4Ti5O12的结构和电化学性能,介绍了Li4Ti5O12的两种合成方法以及掺杂改性研究的现状。     

LiNO3-TiO2-尿素体系燃烧合成锂离子电池负极材料Li4Ti5O12及电化学性能

以纳米TiO2和LiNO3为原料,尿素为燃料,燃烧法合成了锂离子电池负极材料Li4Ti5O12. 利用XRD、SEM和恒电流充放电、循环伏安和交流阻抗对其进行表征. 结果表明,预设炉温850℃,尿素与锂摩尔比1,焙烧8 h,制备得到平均粒径小于500 nm、粒度分布均匀的纯相尖晶石型结构Li4Ti5O12,并具有良好的电化学性能,具有1.5 V充放电平台,在0.1 C倍率下(1 C=170 mA·h/g),其首次充放电容量达到168 mA·h/g,经过100次循环后放电比容量仍有162 mA·h/g,容量保持率96.4%.     

锂离子电池负极材料Li4Ti4.9Ni0.1O12的制备及其电化学性能研究

以 Li2CO3、TiO2、Ni(CH3COO)2.4H2O为原料，采用固相法制备尖晶石型Li4Ti4.9Ni0.1O12锂离子负极材料。通过X射线衍射(XRD)、扫描电镜(SEM)、恒流充放电测试以及交流阻抗等技术对材料进行结构、形貌及电化学性能测试。研究结果表明，制备出的Li4Ti4.9Ni0.1O12材料无杂质相，颗粒大小均匀，在0.5C下首次放电比容量为173.3mAh g-1，库伦效率为97.4%，50次循环后，材料放电比容量为163.4mAh g-1，容量保持率为94.3%。     

不同形貌Li_4Ti_5O_（12）负极材料的研究进展

作为一种新型锂离子电池负极材料,Li4Ti5O12因具有＂零应变＂特性而广受关注。由于材料的形貌对性能有着直接的影响,因而Li4Ti5O12的形貌控制成为研究热点之一。本文综述了包括纳米颗粒、纳米线、纳米棒、纳米纤维、纳米管、纳米片、薄膜以及多孔结构等不同形貌Li4Ti5O12的制备方法和性能研究的最新进展,并对Li4Ti5O12的进一步研究进行了展望。     

锂离子电池负极材料Li4Ti4.9Ni0.1O12的制备及其电化学性能

以Li_2CO_3、TiO_2、Ni(CH_3COO)_2×4H_2O为原料,采用固相法制备尖晶石型Li_4Ti_(4.9)Ni_(0.1)O_(12)锂离子负极材料。通过X射线衍射(XRD)、扫描电镜(SEM)、恒流充放电测试以及交流阻抗等技术对材料进行了结构、形貌表征及电化学性能测试。结果表明,制备的Li_4Ti_(4.9)Ni_(0.1)O_(12)材料无杂相,颗粒大小均匀,在0.5 C下首次放电比容量为173.3 mA×h/g,库伦效率为97.4%,50次循环后,材料的放电比容量为163.4 mA×h/g,容量保持率为94.3%。     

锂离子电池负极材料Li4Ti5O12/C的制备与表征

针对Li₄Ti₅O₁₂导电性和倍率性能差的缺陷,以PEG为碳源采用溶胶-凝胶法制备出电池负极材料Li₄Ti₅O₁₂/C,考察不同分子量聚乙二醇PEG(400、600、1000)做碳源制备的Li₄Ti₅O₁₂/C复合材料电化学性能的优劣,采用热重分析仪(TG)、X射线衍射仪(XRD)、扫描电镜(SEM)、透射电镜(TEM)、恒流充放电、倍率放电、交流阻抗(EIS)等方法对材料进行了结构表征和电化学性能测试。结果表明:以PEG1000为碳源时得到的Li₄Ti₅O₁₂/C,0.1C下首次放电比容量为143.5 mA·h·g^-1,2C的倍率下仍然保持了105 mA·h·g^-1的比容量,容量保持率达到73.17%,并且此材料有最小的电阻,在大电流条件下有良好的电化学性能。     

锂离子电池负极活性材料Li4Ti5O12的研究进展

描述了Li4Ti5O12的晶体结构、性能、合成方法以及掺杂改性的研究现状。Li4Ti5O12作为锂离子电池的负极材料，在Li嵌入和脱出的过程中，其晶型不发生改变，体积变化小于1％，被称之为“零应变材料”。目前主要合成方法为固相反应法和溶胶-凝胶法。     

Mg掺杂对Li4Ti5O12电化学性能的影响

采用高温固相法合成尖晶石型Li4Ti5O12电极材料,研究了镁掺杂对其电化学性能的影响。通过扫描电镜(SEM)、X射线衍射(XRD)手段对材料进行表征,恒电流充放电考察了掺杂产物的电化学性能。Li4-xMgxTi5O12(x=0.1)具有良好的电化学性能和粒度分布,在0.2 C,1 C,3 C,5 C倍率下充放电时,首次充电比容量依次为164.2,158.6,150.8,144.5 mAh/g。结果表明掺杂镁的Li4Ti5O12,其高倍率得到了改善。     

Synthesis and electrochemical properties of La-doped Li4Ti5O12 as anode material for Li-ion battery

La-doped Li₄Ti₅O₁₂ was successfully synthesized from Li₂CO₃, La₂O₃ and tetrabutyl titanate by a simple ball milling assisted modified solid-state method. The impact of La-doping on crystalline structure, particle size, morphology and electrochemical performance of Li₄Ti₅O₁₂ was investigated. The samples were characterized by XRD, SEM, galvanostatically charge–discharge and electrochemical impedance spectroscopy. The results demonstrated that the in-situ coated and ball-milling method could decrease the particle size and prevent the aggregation of Li₄Ti₅O₁₂. La-doping obviously improved the rate capability of Li₄Ti₅O₁₂ via the generation of less electrode polarization and higher electronic conductivity. Li_3.95La_0.05Ti₅O₁₂ exhibited a relatively excellent rate capability and cycling stability. At the charge–discharge rate of 0.5 C and 40 C, its discharge capacities were 176.8 mAh/g and 54.7 mAh/g. After 10 cycles, fairly stable cycling performance was achieved without obvious capacity fade at 0.5 C, 1 C, 2 C, 5 C, 10 C, 20 C and 40 C. In addition, compared to Li₄Ti₅O₁₂, Li_3.95La_0.05Ti₅O₁₂ almost did not have the initial capacity loss. It indicated that Li_3.95La_0.05Ti₅O₁₂ was a promising candidate material for anodes in Li-ion battery application.     

钛酸锂/石墨烯复合负极材料的制备及电化学性能

以Li₂CO₃、锐钛矿TiO₂和石墨烯为原料，采用固相球磨及喷雾干燥相结合的方法制备钛酸锂和钛酸锂/石墨烯复合负极材料。用X射线衍射（XRD）、拉曼光谱、扫描电子显微镜（SEM）表征了样品的晶体结构及形貌。通过恒流充放电测试样品的电化学性能，考察不同石墨烯添加量对钛酸锂材料电化学性能的影响。当石墨烯添加量质量分数为1%时，钛酸锂/石墨烯复合负极材料（LTO-G-2）具有优异的倍率性能及循环稳定性。在0.2C、0.5C、1C、3C、5C和10C倍率下的充电比容量为172.9mA·h/g、165.7mA·h/g、163.5mA·h/g、157.4mA·h/g、154.0mA·h/g和143.5mA·h/g。5C倍率下经历200次循环，容量保持率为94.8%。循环伏安测试(CV)表明LTO-G-2样品的极化程度是最小的。交流阻抗测试（EIS）结果显示LTO-G-2的电荷转移阻抗（69.6Ω）小于纯的钛酸锂的电荷转移阻抗（140.5Ω）。     

Synthesis and electrochemical performance of Li4Ti5O12 submicrospheres coated with TiN as anode materials for lithium-ion battery

The TiN coated Li₄Ti₅O₁₂ (LTO) submicrospheres with high electrochemical performance as anode materials for lithium-ion battery were synthesized successfully by solvothermal method and subsequent nitridation process in the presence of ammonia. The XRD results revealed that the crystal structure of LTO did not change after thermal nitridation process. The submicrospheres morphology of LTO and TiN film on the surface of LTO submicrospheres were characterized by FESEM and HRTEM, respectively. XPS result confirmed that a small amount of Ti changed from Ti⁴⁺ to Ti³⁺ after nitridation process, which will increase the electronic conductivity of LTO. Electrochemical results showed that electrochemical performance of TiN coated LTO anode materials compared favorably with that of pure LTO. Also its rate capability and cycling performance were apparently superior to those of pure LTO. The reversible capacity of TiN-LTO is 105.2 mA h g⁻¹ at a current density of 10 C after 100 cycles and maintain 92.9% of its initial discharge capacity, while that of pure LTO is only 83.6 mA h g⁻¹ with a capacity retention of 90.3%. Even at 20 C, the discharge capacity of TiN coated LTO sample is 101.3 mA h g⁻¹, compared with 77.3 mA h g⁻¹ for pristine LTO in the potential range 1.0–2.5 V (vs. Li/Li⁺).     

Electrochemical performance of Li4Ti5O12 anode material synthesised using polyethylene glycol as a template agent

Low capacity and rate performance are important factors restricting the development of Li₄Ti₅O₁₂ (LTO). The addition of an appropriate amount of polyethylene glycol (PEG) is an effective method to increase the capacity and rate performance of LTO anode material. In this study, LTO anode material was synthesised by the sol–gel method using PEG as a template agent. X-ray diffraction (XRD) results show that the addition of PEG can improve the crystallinity of the material and retain the spinel lattice type of LTO. Scanning electron microscopy (SEM) results show that the addition of an appropriate amount of PEG can promote the formation of a more uniform and much finer morphology. The results of high-resolution transmission electron microscopy (HRTEM) show that the material with PEG had good crystallinity. The charge and discharge data verify that the electrochemical performance of the material could be improved by adding PEG. P2-LTO exhibits a smaller particle size, largest capacity, best cycling performance and best rate performance. The capacity of P2-LTO at 0.2C can reach 224.3 mAgh^?1, which is much higher than the theoretical specific capacity of LTO (175 mAgh^?1). The discharge capacity of P2-LTO in the first cycle at 10C is 178.9 mAgh^?1. The results of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) show that the electrode polarisation and electrochemical impedance of P2-LTO were lower than that of pure LTO. Better capacity and rate performance can be obtained by adding PEG as a template agent to a LTO system. It is a simple and effective method to produce high-performance LTO anode materials.     

Properties of Li4Ti5O12 as an anode material in non-flammable electrolytes

Two non-flammable electrolytes 1 M LiPF₆ in sulfolane (TMS) + 5 wt% VC and 0.7 M lithium bis(trifluoromethanesulphonyl)imide (LiNTf₂) in N-methyl-N-propylpyrrolidinium bis(trifluoromethanesulphonyl)imide (MePrPyrNTf₂) + 10 wt% gamma-butyrolactone (GBL) were tested with Li₄Ti₅O₁₂ (LTO) as highly promising anode material for application in lithium-ion batteries. The results were compared for the titanium anode in the classic electrolyte: 1 M LiPF₆ in propylene carbonate + dimethyl carbonate (PC + DMC, 1:1). The performances of LTO/electrolyte/Li cell were tested using cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge/discharge and scanning electron microscopy (SEM). SEM images of electrodes and those taken after electrochemical cycling showed changes which may be interpreted as a result of solid-state interface formation. Good charge/discharge capacities and low capacity loss at medium C rates preliminary cycling was obtained for the Li₄Ti₅O₁₂ anode. For LTO/1 M LiPF₆ in PC + DMC/Li system, the best capacity was obtained at C/10 and C/3 (145 and 154 mAh g^?1, respectively). In the case of a system working on the basis of a TMS solution (1 M LiPF₆ in TMS + 5 wt% VC) the best value was obtained at a C/5 current and an average of more than 150 mAh g^?1 (86 % of theoretical capacity). For the 0.7 M LiNTf₂ in MePrPyrNTf₂ + 10 wt% GBL electrolyte, the highest capacitance value (at C/20 current) of about 150 mAh g^?1 was observed. The 1 M LiPF₆ in TMS + 5 wt% VC and 0.7 M LiNTf₂ in MePrPyrNTf₂ + 10 wt% GBL electrolytes had a relatively broad thermal stability range and no decomposition peak was observed below 150 °C.     

Enhanced electrochemical performance of core-shell Li4Ti5O12/PTh as advanced anode for rechargeable lithium-ion batteries

A nanocomposite of Li₄Ti₅O₁₂ particles coated with polythiophene (PTh) was fabricated as advanced anode for rechargeable lithium-ion batteries. The conducting PTh layer was successfully coated on the surface of Li₄Ti₅O₁₂ through the in-situ oxidative polymerization method. Benefiting from the core-shell structure, specific capacities as high as 171.5, 168.2 and 151.1 mA h g⁻¹ at 0.2, 1 and 10 C are obtained in the Li₄Ti₅O₁₂/PTh composite. The electrochemical results also show that the Li₄Ti₅O₁₂/PTh exhibits remarkably improved cycling performance as compared with the Li₄Ti₅O₁₂ anode. Moreover, the charge-transfer resistance of Li₄Ti₅O₁₂/PTh electrode is much lower than that of the bare Li₄Ti₅O₁₂, revealing that the PTh coating can significantly increase the electron conductivity between the Li₄Ti₅O₁₂ particles. The excellent electrochemical performance of the as-fabricated Li₄Ti₅O₁₂/PTh composite can be ascribed to the PTh layer which can suppress the dissolution of active material into the LiPF₆ electrolyte and enhance the electron conductivity of Li₄Ti₅O₁₂ nanocrystals. Thus, the Li₄Ti₅O₁₂/PTh composite is an advanced anode for use in high performance lithium-ion batteries application.     

尖晶石型Li4Ti5O12锂离子电池负极材料研究现状

尖晶石型Li4Ti5O12因其在循环过程中具有良好的稳定性和安全性以及优良的快速充电性能,成为锂离子二次电池负极材料研究的热点。较完备的介绍了锂离子电池负极材料尖晶石型Li4Ti5O12的国内外研究制备方法,通过比较,详细描述了各方法存在问题及优缺点,给出了相应问题的解决方案,同时对尖晶石型Li4Ti5O12作为锂离子动力电池负极材料的发展趋势进行了展望,使用Li4Ti5O12负极材料的电池最有可能作为HEV动力电池率先得到应用。     

提高钛酸锂负极材料倍率性能的研究进展

锂离子动力电池目前存在的主要问题为快速充电和安全性能较差。与石墨负极相比,钛酸锂负极能够明显提高锂离子动力电池的快速充电和安全性能,具有较大的应用前景。介绍了钛酸锂的嵌脱锂机制,分析了提高钛酸锂倍率充放电性能的主要方法,发现钛酸锂与金属和碳基材料复合,能够显著提高材料的电化学性能;通过控制钛酸锂形貌,也可得到倍率性能良好的钛酸锂,但是材料的振实密度较低;制备由纳米级一次粒子组成的微米级二次粒子,材料兼具纳米级一次粒子优越的电化学性能和微米级粒子较高的振实密度。总体而言,高性能钛酸锂材料的设计和制备已经取得了重大进展,然而目前钛酸锂电池面临的主要问题是其胀气行为,所以未来的研究重点将是揭示和研究钛酸锂电池的胀气机理和解决机制。     

Synthesis, characterization and electrochemical performance of LiNiVO4 anode material for lithium-ion batteries

A rheological phase reaction method was introduced to synthesize LiNiVO₄ powder material. The product was tested using XRD, SEM and electrochemical measurement methods. It was found that single crystal grain LiNiVO₄ is easily prepared with the rheological phase reaction; the intermediate product NiV(IV)O₃ is the electrochemical active center; the product prepared at 700 °C for 18 h possess the best morphology of single crystal body and exhibits excellent performance as anode material with a small capacity fade. This indicates that LiNiVO₄ is a good anode material for lithium-ion batteries and the rheological phase reaction is a simple, economical and effective method to synthesize a series of functional materials.