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
·
2018
·
IF 5.116
Jianqing Zhou,Qiancheng Zhu,Hao Hu,Wenjuan Chen,Ying Yu
Spinel Li 4 Ti 5 O 12 known as a “zero-strain” anode material for Li-ion battery has attracted much attention because of its superior safety and stability. Herein, we report a novel H 2 O 2 -assisted one-step hydrothermal method to synthesize different ratio Li 4 Ti 5 O 12 /TiO 2 composites with the same amount of raw materials. For the first time, Li 4 Ti 5 O 12 was prepared directly from commercial titania with the presence of H 2 O 2 , and different proportion Li 4 Ti 5 O 12 /TiO 2 composites were fabricated only by adjusting the amount of H 2 O 2 . The reaction mechanism of the novel H 2 O 2 -assisted method was clearly investigated, and H 2 O 2 plays a crucial role in the formation of intermediate Li 1.81 H 0.19 Ti 2 O 5 ·2H 2 O. Further, the electrochemical performance of different ratio Li 4 Ti 5 O 12 /TiO 2 composites have been investigated. This facile method is also applicable for the preparation of Na 2 Ti 6 O 13 /TiO 2 material, and provides us the new way to fabricate composite materials.
研究领域:
材料科学
·
能源存储
·
纳米技术
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 91
·74774-74782
·
IF 3.84
Wenjun Zhu,Hui Yang,Wenkui Zhang,Hui Huang,Xinyong Tao,Yang Xia,Yongping Gan,Xingzhong Guo
A Li4Ti5O12/TiO2/carbon (Li4Ti5O12/TiO2/C) nanocrystalline composite has been successfully synthesized by a facile sol–gel method and subsequent calcination treatment. Moreover, pure Li4Ti5O12, Li4Ti5O12/C and Li4Ti5O12/TiO2 composites have also been synthesized for comparison. All the samples present a nanocrystalline structure with a uniform size distribution, and abundant phase interfaces can be detected for the Li4Ti5O12/TiO2 and Li4Ti5O12/TiO2/C composites. Electrochemical measurements demonstrate that the resultant Li4Ti5O12/TiO2/C composite exhibits a superior rate capability and cycle stability in comparison with pure Li4Ti5O12, Li4Ti5O12/C and Li4Ti5O12/TiO2 composites, which can be attributed to a high grain boundary density, abundant phase interfaces and in situ formed carbon, for storing extra lithium ions, enhancing rapid lithium insertion/extraction kinetics and improving the electron transport rate.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
ChemSusChem
·
2019
·Vol. 12
·期 19
·4412-4420
·
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.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2017
·
IF 2.986
Chunhai Jiang,Shangbiao Liu,Qinghuang Lian,Jing Zhao,Weiqiang Ding,Zhiyang Yu,Renzhong Huang,Zhimin Zou
Nitrogen-doped carbon-coated Li 4 Ti 5 O 12 -TiO 2 (LTO-TO) hybrid microspheres were prepared by heat treating the dry mixture of urea and chemically lithiated dandelion-like TiO 2 microspheres in a stainless steel autoclave at 550 °C for 5 h. The hybrid materials were tested as anode of Li-ion batteries. As compared to the pristine sample, the N-doped carbon-coated LTO-TO microspheres exhibited higher specific capacity at both low and high current rates. Discharge capacities of 184 and 123 mAh g −1 were obtained at 0.2 C and 20 C, respectively. Moreover, the LTO-TO/C electrode showed excellent cycle performance, with a discharge capacity of 121.3 mAh g −1 remained after 300 cycles at 5 C, corresponding to an average capacity degradation rate of 0.073% per cycle. These high specific capacity, excellent rate capability and cycle performance demonstrated the high potentiality of the N-doped carbon-coated LTO-TO microspheres as anode material of both energy storage-type and power-type Li-ion batteries.
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·Vol. 12
·期 29
·18393-18403
·
IF 10.7
Fengjie Zhang,Wenhao Fang,Xiangkun Wu,Xingmei Lu
Currently, addressing the challenges posed by the low energy density of lithium titanate (LTO), a prevalent anode material in lithium slurry batteries (LSBs), is crucial for ensuring high stability, storage capacity, and cycle stability, thereby facilitating the commercialization of LSBs. In this study, a heterostructure (LTO-TOB) was created by integrating nano-TiO2(B) (bronze phase) onto the surface of commercial LTO. The coated TiO2(B) layer significantly increases the specific surface area and wettability, guaranteeing fantastic stability. The pseudo-capacitance lithium storage ability of TiO2(B) boosts the power of the electrochemical reaction. The extra interface in the crystalline phase and the presence of oxygen vacancies serve not just as lithium storage sites, but also accelerate the Li+ diffusivity and enhance the electron conductivity. Furthermore, the diffusion mechanism of lithium ions within LTO-TOB anolyte was examined by using a designed in situ Raman cell. The engineered LTO-TOB anolyte assembled reactor boasts a substantial specific capacity of 209.12 mA h g−1 at 0.5C, coupled with remarkable cycle steadiness (with a mere 0.095% capacity loss per 100 cycles). The reactor exhibits favorable electrochemical characteristics in both intermittent mode and static long-term cyclic mode, thereby highlighting the significance of surface heterostructure modification as a key approach in advancing the progress of LSBs.
研究领域:
材料科学
·
电化学
·
电池技术
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 29
·14339-14351
·
IF 9.931
Chao Huang,Shi-Xi Zhao,Hang Peng,Yuan-Hua Lin,Ce-Wen Nan,Guo-Zhong Cao
Dual-phase hierarchical porous Li4Ti5O12–TiO2 (HP LTO–TO) microspheres were synthesized using a topochemical conversion method and used as an anode material in high power lithium ion batteries, particularly for use in low temperature applications. The HP LTO–TO microspheres are composed of ultra-thin nanosheets with a large specific surface area for interface intercalation reactions and also to provide a much reduced diffusion path for both electrons and lithium ions. The HP LTO–TO electrode was found to exhibit excellent low-temperature cycling capability and rate performance. The discharge capacities of HP LTO–TO under a current rate of 0.2C reached 167 mA h g−1 at 25 °C, 143 mA h g−1 at 0 °C, 130 mA h g−1 at −10 °C, and 94 mA h g−1 at −40 °C. A discharge capacity of 77 mA h g−1 is readily attainable at −20 °C at a high current rate of 5C. The aforementioned high capacity and rate performance at low temperature can be partially attributed to the novel hierarchical porous dual phase microsphere structure made up of thin nanosheets. It is also hypothesized that the co-existence of dual LTO and TO phases may create cation vacancies and/or result in a favorable interface between LTO and TO that permit fast charge and ion transport, even at very low temperatures. This can be attributed to the fact that HP LTO–TO has a relatively low activation energy for Li+ diffusion and a fast surface faradaic reaction, which benefits from the abundant dual-phase interfaces and grain boundaries, as well as the large specific surface area.
研究领域:
材料科学
·
电化学
·
能量存储
✓ 已验证
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
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
危险品化学品经营许可证（带存储）