Self-assembled V2O5 interconnected microspheres produced in a fish-water electrolyte medium as a high-performance lithium-ion-battery cathode

Abstract

Interconnected microspheres of V 2 O 5 composed of ultra-long nanobelts are synthesized in an environmental friendly way by adopting a conventional anodization process combined with annealing. The synthesis process is simple and low-cost because it does not require any additional chemicals or reagents. Commercial fish-water is used as an electrolyte medium to anodize vanadium foil for the first time. Electron microscopy investigation reveals that each belt consists of numerous nanofibers with free space between them. Therefore, this novel nanostructure demonstrates many outstanding features during electrochemical operation. This structure prevents self-aggregation of active materials and fully utilizes the advantage of active materials by maintaining a large effective contact area between active materials, conductive additives, and electrolyte, which is a key challenge for most nanomaterials. The electrodes exhibit promising electrochemical performance with a stable discharge capacity of 227 mAh·g -1 at 1C after 200 cycles. The rate capability of the electrode is outstanding, and the obtained capacity is as high as 278 at 0.5C, 259 at 1C, 240 at 2C, 206 at 5C, and 166 mAh·g -1 at 10C. Overall, this novel structure could be one of the most favorable nanostructures of vanadium oxide-based cathodes for Li-ion batteries.

Transformation of Polyoxometalate into 3D Porous Li‐Containing Oxide: A Case Study of γ‐LiV2O5 for High‐Performance Cathodes of Li‐Ion Batteries

“…For example, Wang et al reported the ESD synthesis of the 3D porous α‐phase V 2 O 5 thin film, the specific capacity of which decreases from 235 to 140 mAh g −1 in only 50 cycles . Among numerous reported V 2 O 5 and V 2 O 5 ‐based composite electrodes, only a few have shown a stable cycling performance with a capacity fading per cycle under 0.1% for two lithium insertion/extraction . Figure f demonstrates the cycling performance comparison of γ‐LiV 2 O 5 ‐ESD and γ‐LiV 2 O 5 ‐CEP at 0.5 C‐rate.…”

Nanoparticles Encapsulated in Porous Carbon Matrix Coated on Carbon Fibers: An Ultrastable Cathode for Li‐Ion Batteries

“…In the first cycle, the reduction peak at 3.4 V corresponds to a phase change from α-V2O5 to ε-Li0.5V2O5; and peaks at 3.1 V and 2.3 V are assigned to the formation of δ-LiV2O5 and ɤ-Li2V2O5, respectively. [19][20][21][22] In the delithiation process, three anodic peaks at 2.5, 3.3 and 3.5 V are revealed, and they are ascribed to the corresponding reversed phase transformations from ɤ-Li2V2O5 to δ-LiV2O5, ε-Li0.5V2O5, and α-V2O5, respectively [35] . The CV curves for the 2 nd and 5 th cycles resembled that of the 1 st cycle suggesting an excellent reversibility of the cycling process.…”

“…[14][15][16] The capacity of the V2O5/3DC-CFs composite electrode in this voltage region is also apparently higher than those of the V2O5 nanostructure electrodes reported in the literature. [21][22][23][24][25][26][27] The cathode material of high-voltage plateau is necessary for increasing the operating voltage of lithium-ion batteries and, subsequently, enhancing the energy density. To have a fair comparison with the results reported previously, the capacities reported below in this work are, however, the total capacities measured for the voltage range from 4.0 to 2.0 V.…”

Recent progress in rate and cycling performance modifications of vanadium oxides cathode for lithium-ion batteries

“…[87] To make up for these disadvantages, scientists came up with great new ideas that construct hierarchical 3D architectures assembled by low-dimensional nanomaterials. The micro-nano secondary architectures not only inherit the original properties of individual units but also derive the comprehensive advantages [89][90][91]. For instance, 3D V 2 O 5 nanospheres consisted of regularly arranged 2D nanosheets were fabricated via a hydrothermal method (Fig.…”