The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Guozhong Cao - One of the best experts on this subject based on the ideXlab platform.
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revitalized interest in Vanadium Pentoxide as cathode material for lithium ion batteries and beyond
Energy Storage Materials, 2018Co-Authors: Jinhuan Yao, Evan Uchaker, Robert C Masse, Guozhong CaoAbstract:Abstract Revitalized interest in Vanadium Pentoxide (V2O5) arises from two very important developments in rechargeable batteries. One is the push on lithium-ion batteries for higher energy density batteries: using lithium metal as anode and searching for higher capacity and high voltage cathode. Using lithium metal anode eliminates the big obstacle for V2O5 cathode that does not come with lithium ions. V2O5 possesses the highest reversible capacity among known cathode materials. Another is the recent intensive research for cathode materials beyond Li-ion batteries (LIBs). In the past several years, interest in complementary alkali-ion battery technologies has seen a tremendous resurgence. Out of the set of alternative chemistries, V2O5 has seen the most considerable and promising gains as a cathode for Na-ion battery (NIB), Mg-ion battery (MIB), and other metal batteries. Unlike LIBs, these systems face a set of new challenges as dictated by the properties of the transported ionic species and the consequent effects on the electrode materials. The purpose of this review is to summarize the most interesting or surprising phenomena, the important questions raised and next experimental and theoretical steps to advance V2O5 cathode materials in the field of metal batteries. This review focused on selected topics covering the influences of surface chemistry, crystallinity, doping, defects, and nanostructures on the lithium-ion intercalation properties and recent developments on other metal batteries including NIBs and MIBs. The perspectives and remaining challenges for V2O5 based cathode materials have been discussed.
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better than crystalline amorphous Vanadium oxide for sodium ion batteries
Journal of Materials Chemistry, 2014Co-Authors: Evan Uchaker, Yanzhen Zheng, Stephanie L Candelaria, Guozhong CaoAbstract:Amorphous and nanocrystalline Vanadium Pentoxide (V2O5) were prepared through a combination of sol–gel processing paired with electrochemical deposition and investigated as cathodes for sodium-ion batteries. Amorphous V2O5 demonstrated superior electrochemical properties upon sodiation as compared to its crystalline counterpart. More specifically, amorphous Vanadium Pentoxide had a measured capacity of 241 mA h g−1, twice the capacity of its crystalline contemporary at 120 mA h g−1. In addition, the amorphous Vanadium Pentoxide demonstrated a much higher discharge potential, energy density, and cycle stability. The development of amorphous materials could enable the usage and design of previously unexplored electrode materials; herein, the possible relationship between the improved sodiation properties and the amorphous structure is discussed.
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enhanced lithium ion intercalation properties of coherent hydrous Vanadium Pentoxide carbon cryogel nanocomposites
Journal of Power Sources, 2010Co-Authors: Jun Liu, Anqiang Pan, Dawei Liu, Xiaoyuan Zhou, Betzaita Betalla Garcia, Shuquan Liang, Guozhong CaoAbstract:Abstract Coherent hydrous Vanadium Pentoxide (V 2 O 5 · n H 2 O)–carbon cryogel (CC) nanocomposites were synthesized by electrodeposition of Vanadium Pentoxide onto the porous carbon scaffold which was derived from resorcinol (R) and formaldehyde (F) organic hydrogels. As-fabricated nanocomposites were characterized by scanning electron microscopy (SEM), along with EDAX and nitrogen sorption isotherms which suggested Vanadium Pentoxide incorporated in the pores of carbon cryogels. The nanocomposites showed much improved discharge capacity and better cyclic stability as compared to hydrous Vanadium Pentoxide films deposited on platinum foil. The discharge capacity of the nanocomposites reached 280 mAh g −1 based on the mass of the vandium Pentoxide at a current density of 100 mA g −1 and it possessed good cycle stability at different discharge rates. The results demonstrated that electrochemical performances, such as specific discharge capacitance and reversibility of the composite electrode, could be greatly enhanced by the introduction of carbon cryogels (CCs) scaffold with three-dimensionally interconnected porous structure in which V 2 O 5 · n H 2 O homogeneously dispersed.
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synthesis and electrochemical properties of Vanadium Pentoxide nanotube arrays
Journal of Physical Chemistry B, 2005Co-Authors: Ying Wang, Katsunori Takahashi, Huamei Shang, Guozhong CaoAbstract:Nanotube arrays of amorphous Vanadium Pentoxide (V2O5) were synthesized via template-based electrodeposition, and its electrochemical properties were investigated for Li-ion intercalation applications. The nanotubes have a length of 10 μm, outer diameter of 200 nm and inner diameter of 100 nm. Electrochemical analyses demonstrate that the V2O5 nanotube array delivers a high initial capacity of 300 mAh/g, about twice that of the electrochemically prepared V2O5 film. Although the V2O5 nanotube array shows a more drastic degradation than the film under electrochemical redox cycles, the nanotube array reaches a stabilized capacity of 160 mAh/g, which remains about 1.3 times the stabilized capacity of the film.
Qingyu Yan - One of the best experts on this subject based on the ideXlab platform.
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Vanadium Pentoxide based cathode materials for lithium ion batteries morphology control carbon hybridization and cation doping
Particle & Particle Systems Characterization, 2015Co-Authors: Xin Huang, Xianhong Rui, Huey Hoon Hng, Qingyu YanAbstract:Vanadium Pentoxide (V2O5) is a promising cathode material for high-performance lithium-ion batteries (LIBs) because of its high specific capacity, low cost, and abundant source. However, the practical application of V2O5 in commercial LIBs is still hindered by its intrinsic low ionic diffusion coefficient and moderate electrical conductivity. In the past decades, progressive accomplishments have been achieved that rely on the synthesis of nanostructured materials, carbon hybridization, and cation doping. Generally, fabrication of nanostructured electrode materials can effectively decrease the ion and electron transport distances while carbon hybridization and cation doping are able to significantly increase the electrical conductivity and diffusion coefficient of Li+. Implementation of these strategies addresses the problems that are related to the ionic and electronic conductivity of V2O5. Accordingly, the electrochemical performances of V2O5-based cathodes are significantly improved in terms of discharge capacity, cycling stability, and rate capability. In this review, the recent advances in the synthesis of V2O5-based cathode materials are highlighted that focus on the fabrication of nanostructured materials, carbon hybridization, and cation doping.
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Vanadium Pentoxide cathode materials for high performance lithium ion batteries enabled by a hierarchical nanoflower structure via an electrochemical process
Journal of Materials Chemistry, 2013Co-Authors: Yuxin Tang, Xianhong Rui, Yanyan Zhang, Tuti Mariana Lim, Zhili Dong, Huey Hoon Hng, Xiaodong Chen, Qingyu Yan, Zhong ChenAbstract:Hierarchical Vanadium oxide nanoflowers (V10O24·nH2O) were synthesized via a simple, high throughput method employing a fast electrochemical reaction of Vanadium foil in NaCl aqueous solution, followed by an aging treatment at room temperature. During the electrochemical process, the anodic Vanadium foil is dissolved in the form of multi-valence Vanadium ions into the solution, driven by the applied electrical field. After being oxidized, the VO2+ and VO2+ ions instantly react with the OH− in the electrolyte to form uniformly distributed Vanadium oxide nanoparticles at a high solution temperature due to the exothermic nature of the reaction. Finally, nucleation and growth of one dimensional nanoribbons takes place on the surface of the nanoparticles during the aging process to form unique hierarchical V10O24·nH2O nanoflowers. Upon heat treatment, the hierarchical architecture of the Vanadium Pentoxide nanoflower morphology is maintained. Such a material provides porous channels, which facilitate fast ion diffusion and effective strain relaxation upon Li ion charge–discharge cycling. The electrochemical tests reveal that the V2O5 nanoflowers cathode could deliver high reversible specific capacities with 100% coulombic efficiency, especially at high C rates (e.g., 140 mAh g−1 at 10 C).
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facile preparation of hydrated Vanadium Pentoxide nanobelts based bulky paper as flexible binder free cathodes for high performance lithium ion batteries
RSC Advances, 2011Co-Authors: Xianhong Rui, Tuti Mariana Lim, Huey Hoon Hng, Jixin Zhu, Weiling Liu, Huiteng Tan, Daohao Sim, Hua Zhang, Qingyu YanAbstract:Hydrated Vanadium Pentoxide (V2O5·0.44H2O, HVO) nanobelts were synthesized by a simply high-yield (e.g. up to ∼99%) hydrothermal approach. The length of these nanobelts was up to several hundred micrometers while the diameter was only ∼20 nm and the thickness was ∼10 nm. Binder-free bulky papers were prepared by using these HVO nanobelts and were tested as Li ion battery cathodes. The unique architecture of the HVO bulky paper provides hierarchical porous channels and large specific surface area, which facilitate fast ion diffusion and effectively strain relaxation upon charge-discharge cycling. The electrochemical tests revealed that the flexible HVO cathode could deliver high reversible specific capacities with ∼100% Coulombic efficiency, especially at high C rates. For example, it achieved a reversible capacity of 163 mAh g−1 at 6.8 C.
Li Qiang Mai - One of the best experts on this subject based on the ideXlab platform.
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three dimensional interconnected Vanadium Pentoxide nanonetwork cathode for high rate long life lithium batteries
Small, 2015Co-Authors: Qiulong Wei, Jinzhi Sheng, Pengfei Zhang, Kalele Mulonda Hercule, Qinqin Wang, Xiujuan Wei, Li Qiang MaiAbstract:Three-dimensional interconnected Vanadium Pentoxide nanonetworks as cathodes for rechargable lithium batteries are successfully synthesized via a quick gelation followed by annealing. The interconnected structure ensures the electron transport of each unit. And their inner porous structure buffer the volume change over long-term repeated lithium ion insertion/extraction cycles, leading to the high-rate long-life cycling performance.
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Hydrated Vanadium Pentoxide with superior sodium storage capacity
J. Mater. Chem. A, 2015Co-Authors: Qiulong Wei, Qin You An, Xiaocong Tian, Jinzhi Sheng, Liang He, Jin Liu, Wei Feng, Li Qiang MaiAbstract:Sodium ion batteries (SIBs), as potential candidates for large-scale energy storage systems, have attracted great attention from researchers. Herein, a V2O5·nH2O xerogel composed of thin acicular interconnected nanowire networks has been synthesized via a facile freeze-drying process. The interlayer spacing of V2O5·nH2O is larger than that of orthorhombic V2O5 due to the intercalation of water molecules into the layer structure. As the cathode of a SIB, V2O5·nH2O exhibits a high initial capacity of 338 mA h g−1 at 0.05 A g−1 and a high-rate capacity of 96 mA h g−1 at 1.0 A g−1. On the basis of combining ex-situ XRD and FTIR spectroscopy, the Na+ ion intercalation storage reactions are discussed in detail. By modeling calculations, the pseudocapacitive behavior makes a great contribution to the high capacities. Our work demonstrates that V2O5·nH2O with large interlayer spacing is a promising candidate for high capacity sodium-based energy storage.
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nanoflakes assembled three dimensional hollow porous v2 o5 as lithium storage cathodes with high rate capacity
Small, 2014Co-Authors: Li Qiang Mai, Qiulong Wei, Jiayang Fei, Pengfei Zhang, Yunlong Zhao, Mengyu Yan, Wen WenAbstract:Three-dimensional (3D) hollow-porous Vanadium Pentoxide (V2 O5 ) quasi-microspheres are synthesized by a facile solvothermal method followed by annealing at 450 °C in air. The interconnected hollow-porous networks facilitate the kinetics of lithium-ion diffusion and improve the performance of V2 O5 to achieve a high capacity and remarkable rate capability as a cathode material for lithium batteries.
Haihui Wang - One of the best experts on this subject based on the ideXlab platform.
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electrospun porous Vanadium Pentoxide nanotubes as a high performance cathode material for lithium ion batteries
Electrochimica Acta, 2015Co-Authors: Guoxue Liu, Min Guo, Liangxin Ding, Suqing Wang, Haihui WangAbstract:Abstract In this work, porous Vanadium Pentoxide (V2O5) nanotubes have been synthesized by a simple electrospinning technique followed by an annealing process with using low-cost inorganic Vanadium precursor. By controlling the annealing time at 400 °C, a small amount of polymer pyrolysis carbon can be retained which improves the conductivity of the porous V2O5 nanotubes. When evaluated as a cathode material for lithium ion batteries, the porous V2O5 nanotubes delivered capacities of 114.9, 99.7 and 79.6 mAh g−1 at 10, 20 and 50C in the voltage range of 2.5-4.0 V, respectively. Moreover, the porous V2O5 nanotubes display good cycling performance, the capacity retention is 97.4% after 200 cycles at 50C. The results indicate that fabricating nanostructured V2O5 with a porous interconnected morphology is an effective way to improve the electrochemical performance of V2O5.
Volker Presser - One of the best experts on this subject based on the ideXlab platform.
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pseudocapacitive desalination of brackish water and seawater with Vanadium Pentoxide decorated multiwalled carbon nanotubes
Chemsuschem, 2017Co-Authors: Volker Presser, Pattarachai Srimuk, Katherine Aristizabal, Soumyadip Choudhury, Frank MucklichAbstract:A hybrid membrane pseudocapacitive deionization (MPDI) system consisting of a hydrated Vanadium Pentoxide (hV2O5)-decorated multi-walled carbon nanotube (MWCNT) electrode and one activated carbon electrode enables sodium ions to be removed by pseudocapacitive intercalation with the MWCNT–hV2O5 electrode and chloride ion to be removed by non-faradaic electrosorption of the porous carbon electrode. The MWCNT–hV2O5 electrode was synthesized by electrochemical deposition of hydrated Vanadium Pentoxide on the MWCNT paper. The stable electrochemical operating window for the MWCNT–hV2O5 electrode was between −0.5 V and +0.4 V versus Ag/AgCl, which provided a specific capacity of 44 mAh g−1 (corresponding with 244 F g−1) in aqueous 1 m NaCl. The desalination performance of the MPDI system was investigated in aqueous 200 mm NaCl (brackish water) and 600 mm NaCl (seawater) solutions. With the aid of an anion and a cation exchange membrane, the MPDI hybrid cell was operated from −0.4 to +0.8 V cell voltage without crossing the reduction and oxidation potential limit of both electrodes. For the 600 mm NaCl solution, the NaCl salt adsorption capacity of the cell was 23.6±2.2 mg g−1, which is equivalent to 35.7±3.3 mg g−1 normalized to the mass of the MWCNT–hV2O5 electrode. Additionally, we propose a normalization method for the electrode material with faradaic reactions based on sodium uptake capacities.
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Vanadium Pentoxide carbide derived carbon core shell hybrid particles for high performance electrochemical energy storage
Journal of Materials Chemistry, 2016Co-Authors: Bastian J. M. Etzold, Teguh Ariyanto, Marco Zeiger, Benjamin Kruner, Nicolas J Peter, Simon Fleischmann, Volker PresserAbstract:A novel, two step synthesis is presented combining the formation of carbide-derived carbon (CDC) and redox-active Vanadium Pentoxide (V2O5) in a core–shell manner using solely Vanadium carbide (VC) as the precursor. In a first step, the outer part of VC particles is transformed to nanoporous CDC owing to the in situ formation of chlorine gas from NiCl2 at 700 °C. In a second step, the remaining VC core is calcined in synthetic air to obtain V2O5/CDC core–shell particles. Materials characterization by means of electron microscopy, Raman spectroscopy, and X-ray diffraction clearly demonstrates the partial transformation from VC to CDC, as well as the successive oxidation to V2O5/CDC core–shell particles. Electrochemical performance was tested in organic 1 M LiClO4 in acetonitrile using half- and asymmetric full-cell configuration. High specific capacities of 420 mA h g−1 (normalized to V2O5) and 310 mA h g−1 (normalized to V2O5/CDC) were achieved. The unique nanotextured core–shell architecture enables high power retention with ultrafast charging and discharging, achieving more than 100 mA h g−1 at 5 A g−1 (rate of 12C). Asymmetric cell design with CDC on the positive polarization side leads to a high specific energy of up to 80 W h kg−1 with a superior retention of more than 80% over 10 000 cycles and an overall energy efficiency of up to 80% at low rates.
