International Journal of Electrochemical Science
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2023
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IF 1.5
Chengyi Zhu,Jianxiong Liu,Xiaohua Yu,Yingjie Zhang,Xiaodong Jiang,Peng Dong,Yannan Zhang
Spinel LiMn2O4 has attracted increasing interest as promising cathode material owing to its low cost, high safety, and environmental friendliness. But the further development of LiMn2O4 is restricted by fast capacity fading upon cycling, especially at high temperatures. Herein, the one-dimensional (1D) Li4Ti5O12 coated LiMn2O4 nanorods (LMO-LTO) are successfully prepared by combining sol-gel and solid-state calcination method and ultimately enhance the cathode utilization in high-temperature and long-cycling conditions. The as-prepared LMO-LTO cathode delivers a high initial discharge capacity of 128.5 mAh g -1 at 0.1 C rate and exhibits a promising discharge capacity over 74.5 mAh g -1 at 10 C rate. Even under an elevated temperature of 55 O C, it still maintains 74.8% of its initial capacity at 1 C rate. Furthermore, the electrochemical impedance spectra (EIS) measurement confirm that compared with the pure LiMn2O4 nanorod, lower the charge transfer resistance (Rct) and enhanced Li + diffusion coefficient are also strong evidences of the improved electrochemical performance of LiMn2O4 nanorods after Li4Ti5O12 coating.
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高影响因子
Energy Storage Materials
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2020
·
IF 16.28
Dongdong Wang,Hongxia Liu,Zhongqiang Shan,Dawei Xia,Ren Na,Haodong Liu,Baohe Wang,Jianhua Tian
Enhancing the electron/ion transfer ability of Li 4 Ti 5 O 12 materials is very important to achieve advanced high-rate and long-life anode in lithium ion batteries (LIBs). Here, for the first time, we report Li 4 Ti 5 O 12 /nitrogen, sulfur co-doped porous graphene composites (LTO/N, S-PG) via one-step facile calcination and activation process by using LiOH as Li source and activating agent. Mechanisms underlying the beneficial effects of N, S co-doped graphene for LTO anode were substantiated by the Density Functional Theory (DFT) calculations, revealing that co-doped N and S atoms not only significantly facilitate Li + adsorption, but also ameliorate Li + diffusion in graphene. Furthermore, the synergistic effects of nanosized LTO and porous graphene endow the composites with efficient Li + diffusion channels and electron-conductive networks. Therefore, the LTO/N, S-PG can deliver extraordinarily high rate capability ( e.g. 130 mA h g −1 at 80 C and 123 mA h g −1 at 100 C), and excellent cycling stability (83.1% capacity retention after 4000 cycles at 20 C). In addition, their superior electrochemical performance was also demonstrated in the full cells with LiNi 0.5 Mn 1.5 O 4 cathode, which displayed 89.5% capacity retention after 500 cycles at 5 C. These results suggest the great promise of using the LTO/N, S-PG as a novel anode material for high-rate and long-life LIBs.
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ELECTROCHIMICA ACTA
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2016
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IF 4.803
Xue Bai,Wen Li,Aijia Wei,Xiaohui Li,Lihui Zhang,Zhenfa Liu
Spinel Li 4 Ti 5 O 12 co-doped with Mg 2+ and F − was synthesized by solid-state reaction of anatase TiO 2 , Li 2 CO 3 , NH 4 F, and Mg(NO 3 ) 2 . For comparison, Mg 2+ -doped and F − -doped Li 4 Ti 5 O 12 were prepared using the same method. The structure and electrochemical performance of the prepared materials were investigated by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, high-resolution transmission electron microscopy, electrochemical impedance spectroscopy, and galvanostatic charge-discharge tests. Using an internal standard and Rietveld refinement, we calculated the lattice parameters of the samples. After co-doping with Mg 2+ and F − , the dopant ions enter the Li 4 Ti 5 O 12 lattice, resulting in the reduction of Ti 4+ to Ti 3+ , and increasing the conductivity of the material. Furthermore, the Mg 2+ and F − co-doping technique resulted in smaller primary particles with a narrow size distribution, factors that can accelerate transfer of Li + between the electrode and electrolyte. Consequently, the Mg 2+ and F − co-doped Li 4 Ti 5 O 12 material exhibits a superior rate performance and delivers discharge capacities of 159.4, 154.1, 146.5, 120.8, 102.7, and 76 mAh g −1 at 0.2C, 0.5C, 1C, 3C, 5C, and 10C, respectively, significantly higher than those of pure Li 4 Ti 5 O 12 (155.4, 138.6, 124.2, 94.1, 76.7, and 52.2 mAh g −1 at the same C-rates). Moreover, the Mg 2+ and F − co-doped Li 4 Ti 5 O 12 showed outstanding cycling stability, and the capacity retention was 99.62% after 150 cycles at 5C rate. Therefore, the Mg 2+ and F − co-doping technique has proven an effective approach to improve the electrochemical performance of Li 4 Ti 5 O 12 .
研究领域:
材料科学
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电化学
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储能技术
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锂离子电池
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2022
·
IF 6.371
Yue Yin,Xian Luo,Benjun Xu
Li 4 Ti 5 O 12 (LTO) is the most promising anode material for lithium-ion batteries owing to its excellent cycle stability and safety. However, the electrochemical performance of LTO at high rates is limited by its low conductivity. Generally, LTO preparation requires organic titanium sources, which are expensive. In this study, inexpensive H 2 TiO 3 was used as the titanium source, LiOH‧H 2 O served as the lithium source, and NH 3 ‧H 2 O was added to control the pH of the solution. Simple one-step liquid-phase deposition and calcination were performed for obtaining in situ self-assembled LTO submicron spheres with stable morphology and excellent electrochemical performance. According to electrochemical performance tests, the sample calcined with 4 mL of 25% NH 3 ‧H 2 O at 700 °C (LTO-4–700) exhibited the best performance. Its discharge capacity remained at 176.4 mAh g −1 over 100 cycles at 87.5 mA g −1 and retained at 136.7 mAh g −1 over 500 cycles at 875 mA g −1 , and its specific capacity was 105.6 mAh g −1 over 1000 cycles, even at a current of 1750 mA g −1 with a retention rate of 96.7%. Furthermore, LTO-4–700 exhibited excellent rate performance at 3500 mA g −1 compared to other samples. Cyclic voltammetry and electrochemical impedance spectroscopy confirmed that submicron spherical LTO-4–700 had a high Li + migration rate and low electrochemical impedance.
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Journal of Physical Chemistry C
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2023
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IF 3.7
Ming Wang,Yue He,Wei Hong,Shi Yi Zhang,Chan Xu Yang,Ding Shen,Xiao Liang Wang,Cheng Yan
At present, the wide commercial application of Li4Ti5O12 (LTO) is limited as an anode for lithium-ion batteries because of its poor conductivity and lower rate performance. In this paper, LTO nanoparticles were embedded in a reduced graphene oxide (rGO) conductive network by an in situ electrostatic self-assembly effect using a simple hydrothermal reduction method. The microstructure and electrochemical performance of the LTO/rGO composite were investigated. The highlighted results showed that LTO nanoparticles were combined with rGO nanosheets by a Ti–O–C covalent bond, which was more stable than other bonding methods. At the same time, the addition of rGO not only enriches the structure and increases the specific surface area but also effectively prevents the agglomeration of LTO. The higher conductivity of LTO nanoparticles was bestowed by the rGO three-dimensional (3D) network, causing structural stability and high electrochemical performance. The LTO/rGO composite has high first discharge capacity (643.9 mAh/g at 0.5C), remarkable rate performance (290 mAh/g at 10C), and excellent cycle stability (271.7 mAh/g after the 1000th cycle at 10C) when tested in a half battery. Furthermore, it has higher discharge capacity (181.8 mAh/g at 1C, the first Coulombic efficiency was 90.1%) and excellent cycle stability (142.8 mAh/g after 500 cycles at 20C) when assembled into a full battery as the anode with commercial LiFePO4 (LFP) as the cathode. The lithium storage mechanism of the LTO/graphene composite was further discussed by first-principles calculations. With the addition of graphene to LTO, the electron transport ability was improved and the diffusion energy barrier was reduced. This made the composite expected to become a promising anode material for lithium-ion batteries.
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JOURNAL OF ALLOYS AND COMPOUNDS
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2019
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IF 4.175
Shuai Zou,Gang Wang,Yiming Zhang,Caihong Xue,Huiyuan Chen,Guijun Yang,Hui Nan,Haomin Wei,Hong Lin
Lithium titanate (Li 4 Ti 5 O 12 , LTO) has several disadvantages as active material for Li-ion batteries (LIBs) such as low conductivity and poor capacity. To overcome these drawbacks and specifically to improve electrical performance of LTO, we used solvothermal method to synthesis LTO and to dope it simultaneously with Al and Mn. Doped LTO was then incorporated into composites containing graphene (G), carbon nanotube (CNT) or carbon quantum dots (CQDs) to enhance specific capacity and conductivity of LIB anodes containing these composites as active materials. To have a further study of different carbon materials composite with doped LTO, these materials we obtained were thoroughly characterized. LTO doping and incorporation into composites not only increased its specific capacity and also decreased its impedance. Al 3+ and Mn 4+ substituted Ti 4+ located at 16 d sites. First cycle specific capacity values and impedance values of anodes consisting of composites containing doped LTO and G, CNT or CQDs were 261.7, 286.2 and 296.5 mA h/g (at C/10 rate) and 13.99, 8.28, 18.79 Ω, respectively. Capacity retention after 100 cycles for these anodes was 84.6, 90.67 and 83.4%. LTO doping by Al 3+ and Mn 4+ and combining it with G, CNT or CQDs effectively improved its electrochemical performance. The best performance was obtained for anodes containing composites consisting of a combination of doped LTO and CNT.
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ChemSusChem
·
2019
·Vol. 12
·期 19
·4412-4420
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IF 7.804
Da Li,Wei Zhao,Lei Cao,Yiying Gao,Yahui Liu,Weijing Wang,Tao Qi
Graphical In the mix : A mixed-surfactant-assisted synthesis of dual-phase Li 4 Ti 5 O 12 -TiO 2 hierarchical microspheres is proposed. The ratio of anionic/cationic surfactant regulates the dual-phase ratio and primary structure morphology of the final product. The optimal sample obtained has a better electrochemical performance than similar state-of-the-art materials. A mixed-surfactant-assisted method was developed to synthesize dual-phase Li 4 Ti 5 O 12 -TiO 2 hierarchical microspheres. The ratio of anionic/cationic surfactant could regulate the primary structure morphology and the dual-phase ratio of the final product, in which the primary structure morphology could be stacked nanosheets, small nanoparticles, or large nanoparticles. The sample with a primary structure morphology of small nanoparticles had the highest specific surface area of 79.38 m 2 g −1 and the best electrochemical performance because of its high Li + migration rate, low polarization, and appropriate TiO 2 content. Its capacity reached 153.5 mA h g −1 at a current rate of 40 C, and it retained nearly 100 % of its capacity after 100 cycles. A self-assembly mechanism of the mixed surfactant was highlighted to explain the formation of hierarchical microspheres. The physical and electrochemical properties of obtained material were correlated effectively.
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JOURNAL OF POWER SOURCES
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2018
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IF 6.945
Chunhai Jiang,Jing Zhao,Huiqing Wu,Zhimin Zou,Renzhong Huang
Hybrid anodes with Li 4 Ti 5 O 12 nanoparticles uniformly embedding in a mesoporous activated carbon matrix are prepared by CO 2 activation of copolymerized resorcinol and hexamethylenetetramine loaded by lithium acetate and tetrabutyl titanate . The Li 4 Ti 5 O 12 /activated-carbon hybrid anodes show increased capacity retention as the activated carbon content in the composite increases, although their overall specific capacity decreases gradually. The hybrid anode with an activated-carbon content of 54 wt% exhibits the highest capacity retention of 67% at 4 A g −1 referencing to that at 0.1 A g −1 . When coupling it with commercial AC cathode, the Li-ion capacitor displays an outstanding high energy density of 38 Wh kg −1 even at a high power density of 7964 W kg −1 . Moreover, an energy density retention of 90.8% after 2000 cycles at 1 A g −1 is preserved, demonstrating its very stable cycle performance. The results reported in this work indicate that the Li 4 Ti 5 O 12 /activated-carbon hybrids prepared by the proposed copolymerization and post-activation process may be very promising anode materials of Li-ion capacitors designed for high power applications.
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Chemistry-An Asian Journal
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2016
·Vol. 11
·期 8
·1273-1280
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IF 4.592
Chenguang Dai,Jing Ye,Shiyong Zhao,Ping He,Haoshen Zhou
Graphical What′s on tap today ? Li 4 Ti 5 O 12 (LTO) and 0.5 Li 2 MnO 3 ⋅0.5 LiNi 0.4 Co 0.2 Mn 0.4 O 2 (NCM) microspheres show a good electrochemical performance and high tap density. The Li 4 Ti 5 O 12 / x Li 2 MnO 3 ⋅(1- x ) LiMO 2 lithium-ion battery system can offer a higher energy density than Li 4 Ti 5 O 12 /LiCoO 2 cells. In this work, we propose an effective way to prepare nanosized Li 4 Ti 5 O 12 (LTO) microspheres and 0.5 Li 2 MnO 3 ⋅0.5 LiNi 0.4 Co 0.2 Mn 0.4 O 2 (NCM) microspheres by similar spray-drying methods. Both obtained materials are accumulated by primary nanoparticles and show a spherical morphology with particle distribution of 10–20 μm. The LTO microspheres deliver a tap density of 1.04 g cm −3 , while the tap density of NCM microspheres is 2.07 g cm −3 , which means an enhanced volumetric energy density. The as-prepared LTO microspheres have a reversible capacity of 170 mA h g −1 at 0.1 C and a capacity retention of 97 % after 250 cycles at 1 C. The NCM microspheres have an initial discharge capacity of 270 mA h g −1 with a corresponding Coulombic efficiency of 88 % at 0.03 C. Both materials show a relatively good rate capability. The Li 4 Ti 5 O 12 /0.5 Li 2 MnO 3 ⋅0.5 LiNi 0.4 Co 0.2 Mn 0.4 O 2 cells deliver a high cathode specific capacity of 273 mA h g −1 and good initial Coulombic efficiency of 88 % at 0.03 C, and can be developed for powering hybrid and plug-in hybrid vehicles.
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Journal of Energy Chemistry
·
2024
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IF 14
Quansheng Li,Xiaofei Sun,Xuesong Mei,Lingzhi Wang,Minxing Yang,Jianlei Cui,Wenjun Wang
The development of energy storage devices with high energy density relies heavily on thick film electrodes, but it is challenging due to the limited ion transport kinetics inherent in thick electrodes. Here, we report on the preparation of a directional vertical array of micro-porous transport networks on LTO electrodes using a femtosecond laser processing strategy, enabling directional ion rapid transport and achieving good electrochemical performance in thick film electrodes. Various three-dimensional (3D) vertically aligned micro-pore networks are innovatively designed, and the structure, kinetics characteristics, and electrochemical performance of the prepared ion transport channels are analyzed and discussed by multiple characterization and testing methods. Furthermore, the rational mechanisms of electrode performance improvement are studied experimentally and simulated from two aspects of structural mechanics and transmission kinetics. The ion diffusion coefficient, rate performance at 60 C, and electrode interface area of the laser-optimized 60-15% micro-porous transport network electrodes increase by 25.2 times, 2.2 times, and 2.15 times, respectively than those of untreated electrodes. Therefore, the preparation of 3D micro-porous transport networks by femtosecond laser on ultra-thick electrodes is a feasible way to develop high-energy batteries. In addition, the unique micro-porous transport network structure can be widely extended to design and explore other high-performance energy materials.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2021
·Vol. 32
·期 5
·6682-6687
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IF 2.478
Liu Zhenjie,Huang Yudai,Wang Xingchao,Zhang Yue,Ding Juan,Guo Yong,Tang Xincun
High performance and low process cost are two contradictory issues, which limited the commercial application of Li 4 Ti 5 O 12 (LTO). Here, defects and TiO 2 co-enhanced LTO have been synthesized by a simple solid-state method. The crystal structure and morphology of the as-synthesized samples were characterized. The results show that the uniform nanoparticles with spinel structure contained defects and TiO 2 . Defects and TiO 2 co-enhanced LTO shows outstanding reversible discharge capacity of 168.2 mAh g −1 at 1 C after 500 cycles. Further, it presents a stability discharge ability of 155 mAh g −1 at 55 °C at 1 C after 500 cycles. The advanced electrochemical performance could be attributed to the defects and TiO 2 in LTO, which enhance conductivity and produce rich reaction interface, facilitating Li + ion diffusion kinetics. The as-synthesized LTO shows high performance in conjunction with low process cost.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
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IF 9.4
Tu Lan,Jinxia Zhou,Tianzheng Xie,Kai Huang,Suichang Ong,Huili Yang,Heng Jiang,Yibo Zeng,Han Zhang,Xuanrui Guo,Linyi Wan,Ying Zhang,Hang Guo
Spinel Li 4 Ti 5 O 12 (LTO), a zero-strain material, is a promising anode material for solid-state thin-film lithium-ion batteries (TFB). However, the preparation of high-performance Li 4 Ti 5 O 12 thin-film electrodes through facile methods remains a significant challenge. Herein, we present a novel approach to prepare a binder- and conductor-free porous Li 4 Ti 5 O 12 (P-LTO) thin-film. This approach polyvinyl alcohol (PVA)-assisted spray deposition and does not require the use of complex or expensive methods. Adding PVA to the precursor solution effectively prevents thin-film cracking during high-temperature annealing, enhances adhesion, and forms a highly interconnected porous structure . This unique structure shortens the lithium-ion diffusion pathways and facilitates electron transport . Therefore, P-LTO thin film electrodes demonstrate exceptional rate capacity of 104.1 mAh/g at a current density of 100C. In addition, the electrodes exhibit ultra-long cycle stability, retaining 80.9 % capacity after 10,000 cycles at 10C. This work offers a novel approach for the preparation of high-performance thin-film electrodes for TFBs.
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