JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2019
·Vol. 30
·期 6
·5866-5873
·
IF 2.195
Zhu Chengyi,Liu Jianxiong,Yu Xiaohua,Zhang Yannan,Zhang Yingjie,Jiang Xiaodong,Wang Sai,Wang Qiang,Dong Peng
Co-doped Li 4 Ti 5 O 12 nanosheets are synthesized via a facile hydrothermal method assisted by mechanical activation technology. The as-prepared Co-doped Li 4 Ti 5 O 12 is characterized by X-ray diffraction, scanning electron microscope and transmission electron microscopy. The morphology measurement shows that the Co-doped Li 4 Ti 5 O 12 still maintain the three-dimensional nanosheet structures and good crystallinity after Co doping. As we expected, Co-doped Li 4 Ti 5 O 12 exhibits higher initial discharge specific capacity, improved cycling performance, and impressive rate capability compared with pristine Li 4 Ti 5 O 12 nanosheets. Even under 20 °C charge/discharge rates, the initial discharge capacity of Co-doped Li 4 Ti 5 O 12 is up to 106 mAh g −1 . The electrochemical impedance spectra measurement further displays that the charge-transfer resistance of Co-doped Li 4 Ti 5 O 12 is much lower than that of pristine one after 20 cycles. The improved electrochemical performance of Co-doped Li 4 Ti 5 O 12 is mainly because the Co doping can effectively enlarge the size of the channel by altering the lattice parameter, which can facilitate Li + diffusion and electron transportation.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
SOLID STATE IONICS
·
2020
·
IF 3.107
Yuanyu Wang,Wenjun Zhu
Herein, porous Li 4 Ti 5 O 12 has been prepared by a facile sol-gel process with poly(ethylene oxide) used as a phase separation inducer, which presents a novel micro/nano structure with micro-sized secondary structure (2–5 μm) constructed by many interconnected nano-sized primary components (30–60 nm). As an anode material for lithium ion batteries , the as-prepared Li 4 Ti 5 O 12 exhibits good cycling stability and rate capability, which could be attributed to the unique porous micro/nano structure.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 32
·15755-15761
·
IF 9.931
Sainan Luo,Pengcheng Zhang,Tao Yuan,Jiafeng Ruan,Chengxin Peng,Yuepeng Pang,Hao Sun,Junhe Yang,Shiyou Zheng
Spinel lithium titanate (Li4Ti5O12, LTO) is one of the most appealing anode materials for lithium-ion batteries (LIBs) due to its long cycle life and high safety performance. However, its low intrinsic electronic conductivity limits its high rate capability. Herein, we develop a novel one-pot in situ molecular self-assembly approach to prepare a dual N- and anatase-TiO2- modified Li4Ti5O12/C nanorod material (NT-LTO/C). Polypyrrole (PPy), as a pivotal carbon and nitrogen source, is introduced to confine the morphology and particle size of the NT-LTO/C anode. Due to the synergistic effects of the multilevel particle structure, uniform carbon coating, N doping, anatase TiO2 pseudopotential effect and such benefits, the NT-LTO/C electrode delivers a high reversible capacity of 196.3 mA h g−1 at 0.5C, and it maintains 105.5 mA h g−1 even at an ultrahigh rate of 100C with progressive cycling of more than 3000 cycles. In addition, the three electrode pouch full-cell shows much smaller polarization than the pristine one. This novel and facile molecular self-assembly method has broad advanced functional material applications including for ceramics, polymer/carbon-based metal alloys and inorganic non-metallic materials.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
FIRE TECHNOLOGY
·
2019
·Vol. 56
·期 6
·2349-2364
·
IF 1.42
Zheng Hao,Fang Wei,Sun Yi,Liang Xin,Xiang Hongfa,Jiang Lihua,Wang Qingsong
Nonflammable electrolytes are promising substitutes for the state-of-the-art carbonate-based electrolytes in order to directly enhance the safety characteristics of lithium ion batteries. Combination of trimethyl phosphate (TMP) and a fluorinated ether of 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (FEPE) is designed to formulate nonflammable electrolytes. The reformulated electrolytes of 1 mol/L LiPF 6 /TMP + FEPE (9:1, 8:2 and 7:3, w/w) are totally nonflammable. The FEPE solvent has higher oxidative stability and the FEPE-containing electrolytes have better separator wettability than the pure TMP electrolyte (1 mol/L LiPF 6 /TMP). The improved oxidative stability and separator wettability can enhance electrochemical stability of electrolyte on high-voltage cathode LiNi 0.5 Mn 1.5 O 4 . In Li 4 Ti 5 O 12 /LiNi 0.5 Mn 1.5 O 4 cells, the FEPE-containing electrolyte exhibits the better cycling stability than the pure TMP electrolyte, and the solvent composed of TMP + FEPE (8:2) is the optimal ratio. The Li 4 Ti 5 O 12 /LiNi 0.5 Mn 1.5 O 4 cell with the optimal electrolyte exhibits better rate capability because of the reduced polarization and improved oxidation stability. This work reveals the effect of fluorinated ethers on separator wettability of TMP-based nonflammable electrolytes and high-voltage applications.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2019
·Vol. 166
·期 4
·A658
·
IF 3.12
Zhenya Wang,Limei Sun,Wenyun Yang,Jinbo Yang,Kai Sun,Dongfeng Chen,Xiangfeng Liu
Li4Ti5O12 (LTO) has attracted great interest as an anode material due to the "zero strain" during Li+ insertion and extraction. But the intrinsic ionic diffusion coefficient and electronic conductivity are very poor. Herein, a strategy of Mg2+ and Zr4+ co-doping has been proposed to modulate the crystal structure and improve the electrochemical performances. More importantly, the synergic roles of Mg/Zr co-doping has been unveiled based on the analysis of X-ray diffraction, Neutron powder diffraction, X-ray photoelectron spectroscopy, and electrochemical measurements. Firstly, Mg-Zr co-doping expands the lattice parameter, cell unit volume and even Li-O bond length, which reduces Li+ migration barrier and benefits to Li+ insertion/extraction. Secondly, Ti-O shrinkage induced by Mg-Zr co-doping enhances the structure stability and subsequently the cycle performance. Thirdly, Mg-Zr co-doping promotes more Ti4+/Ti3+ which facilitates electron conductivity. Moreover, Mg-Zr co-doping also decreases the polarization and charge transfer impedance. Li3.8Mg0.2Ti4.9Zr0.1O12 delivers a discharge capacity of 180.5, 150.7, 110.4 and 78.9 mAh/g at 0.2C, 1C, 5C and 10C, respectively. Moreover, the capacity retention is greatly increased from 57.9% of LTO to 98.59% at 10C after 500 cycles.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2022
·
IF 9.794
Chen Lv,Wenjie He,Jiangmin Jiang,Enmeng Zhen,Hui Dou,Xiaogang Zhang
The manufacturing processes of electrodes have a prominent influence on the cost and performance of lithium-ion capacitors (LICs), which are limited by the conventional wet-coated method due to the usage of solvent. Herein, the solvent-free Li 4 Ti 5 O 12 (LTO) electrodes are prepared with electrostatic spraying deposition using for LICs. Owing to the solvent being avoided during the manufacturing, the dry-sprayed electrode exhibits a higher porosity (∼40%) than that of the wet-coated electrode (∼30%), together with a larger electrochemically active surface area. The optimized microstructure improves electrolyte infiltration and offers effective Li-ion transport paths, which reduces the electrochemical polarization and boosts the specific capacity of the dry-sprayed electrode. When the current density increases from 0.5 C to 10 C, the reversible capacity retention of the dry-sprayed electrode is 74%, which is higher than that of the wet-coated electrode (56%). In addition, the powder resistivity of the dry-sprayed electrode decreases sharply by introducing two-dimension (2D) graphene nanoplate (GN) as the conductive agent, thus side effects have been effectively suppressed during the spraying process. As a result, the assembled LICs using the dry-sprayed LTO electrodes show superior energy density and excellent cycling performance, demonstrating this novel fabrication method has practical application prospects.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2015
·
IF 2.729
Shengyang Dong,Xiaoyan Wang,Laifa Shen,Hongsen Li,Jie Wang,Ping Nie,Jingjie Wang,Xiaogang Zhang
To enhance kinetics of lithium insertion/extraction of anode materials for hybrid lithium-ion capacitors (hybrid LICs), we develop a new applicable strategy toward the synthesis of trivalent Ti self-doped Li 4 Ti 5 O 12 nanoparticles . Starting with Ti 2 O 3 , we show that subsequent solid state reaction with Li 2 CO 3 leads to the formation of trivalent Ti self-doped Li 4 Ti 5 O 12 . The presence of trivalent Ti gives rise to high electric conductivity and the nanostructure reduces the transport path lengths of lithium-ions and electrons, permitting fast kinetics for both transported lithium-ions and electrons, thus enabling high-power performance. A high performance hybrid LIC is fabricated by using Ti 3 + self-doped Li 4 Ti 5 O 12 as an insertion-type anode and activated carbon derived from outer peanut shell as cathode, which delivers high energy density (67 Wh kg − 1 ), high power density (8000 W kg − 1 ). Additionally, the device still retains about 79% of its original capacity even after 5000 cycles at 0.5 A g − 1 .
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Zhixin Ye,Feifei Zhong,Yunfei Chen,Zhimin Zou,Chunhai Jiang
Composite anode materials with a unique architecture of carbon nanotubes (CNTs)-chained spinel lithium titanate (Li 4 Ti 5 O 12 , LTO) nanoparticles are prepared for lithium ion capacitors (LICs). The CNTs networks derived from commercial conductive slurry not only bring out a steric hindrance effect to restrict the growth of Li 4 Ti 5 O 12 particles but greatly enhance the electronic conductivity of the CNTs/LTO composites, both have contributed to the excellent rate capability and cycle stability. The capacity retention at 30 C (1 C = 175 mA g −1 ) is as high as 89.7% of that at 0.2 C with a CNTs content of 11 wt%. Meanwhile, there is not any capacity degradation after 500 cycles at 5 C. The LIC assembled with activated carbon (AC) cathode and such a CNTs/LTO composite anode displays excellent energy storage properties, including a high energy density of 35 Wh kg −1 at 7434 W kg −1 , and a high capacity retention of 87.8% after 2200 cycles at 1 A g −1 . These electrochemical performances outperform the reported data achieved on other LTO anode-based LICs. Considering the facile and scalable preparation process proposed herein, the CNTs/LTO composites can be very potential anode materials for hybrid capacitors towards high power-energy outputs.
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 16
·13505-13513
·
IF 3.289
Wenjun Zhu,Hui Yang,Xingzhong Guo
Porous ellipsoid-like Li4Ti5O12–TiO2 composites with a unique micro/nano structure have been successfully fabricated via a facile sol–gel route followed by calcination. The porous ellipsoid-like particles with micro/nano structures are formed through phase-separation induced by poly(ethylene oxide) (PEO), which are constructed using numerous nanocrystals with sizes of about 50–100 nm consisting of lithium titanate, anatase and rutile. The resultant Li4Ti5O12–TiO2 composite shows a superior rate capability and cycling stability in comparison with pure Li4Ti5O12, which delivers a reversible capacity over 92 mA h g−1 at 10C after 100 cycles as well as an acceptable rate capacity of 89 mA h g−1 at a high rate of 30C. The excellent electrochemical performance of the Li4Ti5O12–TiO2 composite is attributed to the unique micro/nano and multiphase structures. The micro/nano structure enhances the structure stability and shortens the diffusion distance for both electron and lithium ions. Moreover, the abundant phase interfaces and grain boundaries store extra lithium ions and guarantee rapid lithium insertion/extraction kinetics.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2020
·
IF 6.215
Hanyong Wang,Lecai Wang,Jiao Lin,Jingbo Yang,Feng Wu,Li Li,Renjie Chen
The use of Li 4 Ti 5 O 12 , which is a zero-strain material, as an anode material for lithium-ion batteries is hampered by its low electronic conductivity and low lithium-ion diffusion coefficient . In this study, we design a hierarchically structured Li 4 Ti 5 O 12 material with a conductive carbon coating to improve the material's electrochemical properties. Hexadecyl trimethylammonium bromide is used as a structure-guiding agent and as a carbon source together with glucose. The discharge specific capacities of the obtained materials are 170.37, 167.34, 163.05, 158.03, and 151.49 mA h g −1 at rates of 0.5, 1, 2, 5, and 10 C, respectively. Even at a high rate, namely 25 C, for 500 cycles, a discharge specific capacity of 144.05 mA h g −1 with 96.3% capacity retention is achieved. We believe that hierarchical Li 4 Ti 5 O 12 materials with a carbon coating have potential applications as anode materials for the future development of lithium-ion batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Advanced Energy Materials
·
2022
·Vol. 12
·期 13
·2103112
·
IF 29.698
Xiaosong Xiong,Wenqi Yan,Yusong Zhu,Lili Liu,Lijun Fu,Yuhui Chen,Nengfei Yu,Yuping Wu,Bin Wang,Rui Xiao
Lithium metal is regarded as the most promising electrode material for the next generation of energy storage devices. However, low coulombic efficiency and short cycle lifespan caused by the unstable electrode interface have hindered its practical application. Constructing artificial coatings on the anode is one of the most effective approaches for remedying this, but the practical effects are still limited due to their poor regulation of Li + ions transport and complex construction engineering. Herein, an “inverse concentration gradient” concept is put forward to improve the lithium metal anode, especially at high current density. A Li 4 Ti 5 O 12 artificial coating layer is fabricated on copper foil by a simple droplet coating method and a concentrated Li + ions region near the electrode interface in the coating layer is formed in situ after the initial activation process, which alleviates the effects of space charge regions generated by ion depletion on the growth of lithium dendrites. Coupled with high ionic conductivity and “zero strain” characteristics, stable dendrite-free cycling of lithium metal anodes is achieved even at 5 mA cm −2 in Li/Cu half cell. The unique concentration gradient design provides a new perspective for the interface regulation of advanced lithium metal anodes.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Lingyao Zou,Lu Gan,Wenli Song,Chunying Rong,Lishan Yang,Liping Yu,Zhongyun Ma,Shixun Lian
The rapid development of highly durable electric vehicles has put forward higher requirements for lithium-ion batteries. Li 4 Ti 5 O 12 (LTO) is widely studied owing to its long service life and safety. However, owing to their low electrical conductivity and diffusion, lithium ions have limited practical applications. In this study, Co-Cl co-doped LTO/TiO 2 diphase (LTOT) nanosheets were prepared via the hydrothermal method . The synergistic effect of Co-Cl co-doping reduced the charge-transfer resistance of LTOT and increased the lithium-ion diffusion coefficient , thereby improving the dynamic behavior of the electrode material, which further enhances the rate capability and cycle performance of LTOT. The optimized LTOT:Co-Cl composite exhibited excellent cycle performance and rate capability (the ninth cycle reversible capacities were 253.8, 222.2, 200.1, 185.7, 169.9, 161.3, and 146.3 mAh·g −1 at the current density of 1, 2, 5, 10, 20, 30, and 50 C (1 C = 175 mA·g −1 ) rate, respectively). In addition, LTOT:Co-Cl maintained a capacity of 120 mAh·g −1 after 5000 cycles at 50 C with a retention rate of 83 %, indicating that the average decay rate per cycle is only 0.003 % during the long charge/discharge process.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）