ChemNanoMat
·
2024
·
IF 2.6
Jiangnan Guo,Shuozhen Hu,Xinsheng Zhang,Shigang Sun
Utilizing carbon coated ferroelectric materials to introduce polarization-induced electric field (PIEF) stimulates research of electric field-assisted catalysts for various reactions. However, effect of PIEF on carbon coating mechanism has not been studied. Herein, tourmaline nanoparticles (TNPs) with spontaneous dipole moments were applied as the PIEF supplier and sucrose was utilized as the carbon precursor to synthesize carbon coated TNPs (TNP@SC) to uncover the influence of PIEF on the carbon coating and catalytic activity of Pd toward formic acid decomposition (FAD). PIEF enhanced the adsorption capacity of TNPs for the caramelized intermediate species and increased H+ concentration by facilitating water ionization. Polymerization of adsorbed caramelized intermediate species on TNPs was accelerated. Uniformly coated carbon layer with more defects, larger specific surface area, and higher porosity was coated on TNP. Such surface properties of the carbon layer were beneficial for strongly anchoring ultrafine Pd nanoparticles. Owing to the specific properties of carbon layer and existence of PIEF, Pd/TNP@SC exhibited higher FAD activity than the catalysts absent of PIEF. Stronger PIEF leaded to higher initial turnover frequency. This study provides guidance to supply electric field for catalysis.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Mingwei Liang,Weijing Wang,Yi Jiang,Chenyang Liao,Qin Long,Xuefei Lai,Li Liao
The commercial application of silicon is still impeded by poor conductivity and significant volume change. In this work, a C@Si@G composite was synthesized by a facile chemical solution reaction and carbonization procedure with cocoon silk as a natural carbon source. This composite has a sandwich structure, where Si nanoparticles as a sandwich middle layer and graphene (G) as an out layer. And it possesses the advantages of flexible, nitrogen-doped and is environmentally friendly. The optimized C@Si@G-15 composite is used as a self-supporting anode without a current collector, and it shows a reversible discharge capacity of 972 mAh g −1 after 120 cycles at 1 A g −1 and a relatively high capacity of 1070 mAh g −1 after 300 cycles at 200 mA g −1 , demonstrating the effect of coating the N-doped carbonized silk and the graphene synergistically to improve electrical connectivity and to constrain the pulverization of Si nanoparticles. Hence, it delivers great potential for application on wearable devices .
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale Research Letters
·
2014
·Vol. 9
·期 1
·1-5
·
IF 2.481
Wang Yanming,Wang Yajing,Wang Fei
Well-crystallized Li 2 NiTiO 4 nanoparticles are rapidly synthesized by a molten salt method using a mixture of NaCl and KCl salts. X-ray diffraction pattern and scanning electron microscopic image show that Li 2 NiTiO 4 has a cubic rock salt structure with an average particle size of ca. 50 nm. Conductive carbon-coated Li 2 NiTiO 4 is obtained by a facile ball milling method. As a novel 4 V positive cathode material for Li-ion batteries, the Li 2 NiTiO 4 /C delivers high discharge capacities of 115 mAh g -1 at room temperature and 138 mAh g -1 and 50°C, along with a superior cyclability.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF POWER SOURCES
·
2015
·
IF 6.217
Honglai Zhang,Zhaohui Li,Shishun Yu,Qizhen Xiao,Gangtie Lei,Yanhuai Ding
Carbon-encapsulated LiMn 2 O 4 (LMO@C) spheres were prepared using polymer microgel reactor, in which Mn 2+ ions are hydrolyzed in situ to form Mn(OH) 2 , and followed by annealing at a high temperature. The LMO@C spheres are constructed with the spinel LiMn 2 O 4 nanospheres that embedded in a porous carbon matrix uniformly. Owing to possessing three-dimensional (3D) electron-conductive and 3D ion-conductive networks, the LMO@C spheres exhibit high rate capability. They can deliver the specific capacities of 142, 137, 126, 107, and 91 mAh g −1 at the rates of 0.1C, 1C, 5C, 10C, and 20C (1C = 148 mA g −1 ), respectively. Owing to carbon encapsulation, the LMO@C spheres can retain 80% of the initial capacity at 1C rate after 1000 cycles at 25 °C, displaying stable cycling performance. The results suggest that the LMO@C spheres are promising cathode materials for high-power lithium-ion batteries.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Huying Yan,Yang Guo,Xingzhi Bai,Jiawei Qi,Xiangyu Zhao,Haipeng Lu,Longjiang Deng
Developing a lightweight microwave absorbing materials (MAMs) with high absorption capacity at low thickness is a perennial challenge in materials engineering. Herein, a light Ti 3 C 2 T x @Carbon/NiZn ferrite (Ti 3 C 2 T x @C/NZFO) composite is designed by synergistically incorporating dielectric–magnetic components. The inclusion of C and NZFO enhances the interfacial polarization of the substrate and optimizes its impedance matching. Additionally, the presence of NZFO also produces magnetic loss mechanisms, such as natural and exchange resonance, as well as eddy current loss. Spontaneously, Ti 3 C 2 T x @C/NZFO composite achieved a minimum reflection loss ( RL ) of –44.7 dB at 12.5 GHz and displayed an effective absorption bandwidth of 4.27 GHz (13.53–17.8 GHz) at a thin thickness of 1.3 mm ( RL < –10 dB). Besides, the Ti 3 C 2 T x @C/NZFO composite exhibits the smallest radar cross–section (RCS) value, which further corroborates its outstanding microwave absorption performance. This research offers a groundbreaking approach to designing lightweight and thin MAMs.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Renming Zhan,Bolei Shen,Qiuju Xu,Youquan Zhang,Yushan Luo,Heng Liu,Hao Chen,Feng Liu,Changming Li,Maowen Xu
Pristine Na 3 Fe 0.5 V 1.5 (PO 4 ) 3 and carbon-coated Na 3 Fe 0.5 V 1.5 (PO 4 ) 3 nano-particles are synthesized by one-step solid-phase reaction method. The full battery based on Na 3 Fe 0.5 V 1.5 (PO 4 ) 3 @C nano-particles as cathode and commercial hard carbon as anode outputs a high working voltage about 3.3 V and exhibits superior-rate performance. While the rate increases from 0.5 to 1, 2 and 5 C, the discharge capacity of full battery slightly decreases from 110 to 94, 88, 79 mA h g −1 gradually. Moreover, it shows excellent cycle stability with a capacity retention of 93.8% after 200 cycles at 0.5 C.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Waste and Biomass Valorization
·
2018
·Vol. 11
·期 5
·2201-2209
·
IF 1.874
Tong Zizheng,Qi Yuruo,Zhao Junmei,Liu Lilu,Shen Xing,Liu Huizhou
In this work, a one-step hydrothermal strategy has been developed for the synthesis of carbon-coated Na 3 (VOPO 4 ) 2 F with the aid of biomass (e.g. glucose, fructose or starch), where biomass plays the key role of carbon source and reducing agent for reducing vanadium(V) to vanadium(IV). The effect of different biomass on the morphologies has been examined. Furthermore, the synthetic mechanism was deduced by investigating the impact of hydrothermal time on the synthesis. In addition, the vanadium oxidation state has been finally confirmed by XPS and UV–Vis. The as-synthesized carbon-coated Na 3 (VOPO 4 ) 2 F shows a superior long-term cycling performance, such as the capacity retentions are higher than 70% after 1400 cycles at a current rate of 5 C. The higher content of carbon will lead to the better rate capability. The present study suggests that the one-step hydrothermal technique using biomass as a reducing agent appears to be a facile and green low-cost approach to prepare the promising cathode material Na 3 (VOPO 4 ) 2 F.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2025
·
IF 7.9
Yangchenyi Wu,Shanyu Wang,Yang Wu,Fuzhong Wu,Jie Tang
Silicon (Si) is living with severe pulverization of active materials, continuous breakage of structure in electrode, and turbulent solid electrolyte interphase (SEI) because of huge volume variation during (dis)charging. Herein, from the view of the active material and electrode structure, the innovative dual modification that combines carbon coating and Ti 3 C 2 T x as conductive agents is adopted, generating more than simply pooling their efforts together. The resultant Si@C-M electrodes exhibit an excellent rate capacity of 1538.1 mA h g −1 at 5 A g −1 and maintain capacity retention of 80.5 % with 1084.8 mA h g −1 after 300 cycles at 1 A g −1 . The sterling performance is thanks to the stable electrode provided by the coating-carbon and Ti 3 C 2 T x which not only reduces interface impedance, and enhances Li-ion diffusion, but suppresses the volume variation of electrodes as well effectively as verified by in situ and ex situ characterization. Moreover, utilizing the Ti 3 C 2 T x as the conductive agent is beneficial to forming benign SEI rich in LiF and Li 2 O. This work provides a potential strategy and exploits new routes for the practical utilization of high-energy-density lithium-ion batteries (LiBs).
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
MOLECULES
·
2021
·Vol. 26
·期 11
·3211
·
IF 4.412
Shugui Song,Jingcang Li,Anqi Zheng,Yongqiang Yang,Kuibo Yin
To address the challenge of the huge volume expansion of silicon anode, carbon-coated silicon has been developed as an effective design strategy due to the improved conductivity and stable electrochemical interface. However, although carbon-coated silicon anodes exhibit improved cycling stability, the complex synthesis methods and uncontrollable structure adjustment still make the carbon-coated silicon anodes hard to popularize in practical application. Herein, we propose a facile method to fabricate sponge-like porous nano carbon-coated silicon (sCCSi) with a tunable pore structure. Through the strategy of adding water into precursor solution combined with a slow heating rate of pre-oxidation, a sponge-like porous structure can be formed. Furthermore, the porous structure can be controlled through stirring temperature and oscillation methods. Owing to the inherent material properties and the sponge-like porous structure, sCCSi shows high conductivity, high specific surface area, and stable chemical bonding. As a result, the sCCSi with normal and excessive silicon-to-carbon ratios all exhibit excellent cycling stability, with 70.6% and 70.2% capacity retentions after 300 cycles at 500 mA g−1, respectively. Furthermore, the enhanced buffering effect on pressure between silicon nanoparticles and carbon material due to the sponge-like porous structure in sCCSi is further revealed through mechanical simulation. Considering the facile synthesis method, flexible regulation of porous structure, and high cycling stability, the design of the sCCSi paves a way for the synthesis of high-stability carbon-coated silicon anodes.Keywords:carbon-coated silicon;porous structure;mechanical simulation;lithium-ion battery
研究领域:
材料科学
·
电化学
·
能源存储
✓ 已验证
产品关联
DOI
PubMed
高影响因子
IONICS
·
2014
·Vol. 21
·期 5
·1269-1275
·
IF 1.836
Xue Liang,Liao Youhao,Yang Liang,Li Xiaoping,Li Weishan
Carbon-coated LiNi 0.5 Mn 1.5 O 4 cathode was prepared using phenolic resin as a carbon precursor. The morphology and structure of the prepared samples were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and thermogravimetry, and its performance as cathode of lithium ion battery was investigated by electrochemical impedance spectroscopy and charge-discharge test. The results showed that the carbon coating with phenolic resin as precursor could obviously promote the discharge capacity of LiNi 0.5 Mn 1.5 O 4 cathode, especially at high rate. At 20 C rate, the discharge capacity is 41 mAh∙g -1 for uncoated LiNi 0.5 Mn 1.5 O 4 , while 108 mAh∙g -1 for carbon-coated LiNi 0.5 Mn 1.5 O 4 . The coated sample also exhibited excellent cyclic performance, remaining 95 % of its initial discharge capacity (131 mAh∙g -1 ) at 1 C rate after 100 cycles. The interfacial resistance of LiNi 0.5 Mn 1.5 O 4 with carbon coating was reduced from 90 to 31 Ω.
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 POWER SOURCES
·
2015
·
IF 6.217
Jugong Zheng,Liang Ni,Yanwen Lu,Cancan Qin,Panxing Liu,Tongfu Wu,Yuefeng Tang,Yanfeng Chen
LiMnPO 4 is proposed as more promising cathode material as LiFePO 4 , while poor electronic conductivity and Jahn-Teller effects during charge/discharge processes hinder the electrochemical performance. To overcome these problems, one-step solid state reaction method is developed to synthesize LiMnPO 4 /C composites, which is with nanostructure , high crystallinity and good carbon coating. Manganese oxide sources and calcination temperature are investigated as factors for preparing high-performance LiMnPO 4 /C for Li-ion batteries. The results show that the LiMnPO 4 /C composites prepared with mixed manganese oxide deliver a superior initial capacity of 153 mAh g −1 at 0.05 C and high rate performance with discharge capacities of 123 mAh g −1 at 1 C and 103 mAh g −1 at 2 C. And the LiMnPO 4 /C composites synthesized at 600 °C can retain 94% of the initial capacity after 200 cycles at 1 C, revealing a stable cycling stability. Therefore, one-step solid state reaction brings to light the synthesis of high performance LiMnPO 4 /C cathode materials and is suitable for large scale production.
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
·
2015
·Vol. 3
·期 29
·15299-15306
·
IF 7.443
Jugong Zheng,Cancan Qin,Tongfu Wu,Shuangfei Xie,Liang Ni,Muyang Peng,Yuefeng Tang,Yanfeng Chen
Preparing high-performance LiMnPO4 is still a large obstacle due to its sluggish electrochemical kinetics. To overcome this problem, a novel method is developed for LiMnPO4/C nanoplates from nanoporous Mn2O3 precursors. There are two advantages. Firstly, through negative pressure immersion, lithium dihydrogen phosphate (LiH2PO4), lithium hydroxide (LiOH) and sucrose (C12H22O11) are deposited on the surface of porous Mn2O3 nanosheets. In the following solid-state reaction, three dimensional continuous conductive carbon is wrapped uniformly around the LiMnPO4/C nanoplates, which greatly improved the conductivity. Secondly, (010) exposed facets are obtained using the Mn2O3 hierarchical microspheres as precursors, which allows for a fast transmission of Li+ ions improving the rate capability. As a result, the as-synthesized L-Mn2O3-LMP/C samples exhibit a superior rate performance with discharge capacities of 157.3 mA h g−1 at C/20, 122.6 mA h g−1 at 1C, and 105.8 mA h g−1 at 2C. Meanwhile, they can retain 99.3% of the initial capacity after 100 cycles at 1C, revealing an excellent cycling stability. This method sheds more light on the fabrication of high-performance LiMnPO4/C cathode materials and is suitable for large scale productions.
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）