Nanostructured Vanadium Oxide Electrodes for Enhanced Lithium‐Ion Intercalation

Abstract

This article summarizes our most recent studies on improved Li+‐intercalation properties in vanadium oxides by engineering the nanostructure and interlayer structure. The intercalation capacity and rate are enhanced by almost two orders of magnitude with appropriately fabricated nanostructures. Processing methods for single‐crystal V2O5 nanorod arrays, V2O5·n H2O nanotube arrays, and Ni/V2O5·n H2O core/shell nanocable arrays are presented; the morphologies, structures, and growth mechanisms of these nanostructures are discussed. Electrochemical analysis demonstrates that the intercalation properties of all three types of nanostructure exhibit significantly enhanced storage capacity and rate performance compared to the film electrode of vanadium pentoxide. Addition of TiO2 to orthorhombic V2O5 is found to affect the crystallinity, microstructure, and possible interaction force between adjacent layers in V2O5, and subsequently leads to enhanced Li+‐intercalation properties in V2O5. The amount of water intercalated in V2O5 is found to have a significant influence on the interlayer spacing and electrochemical performance of V2O5·n H2O. A systematic electrochemical study has demonstrated that the V2O5·0.3 H2O film has the optimal water content and exhibits the best Li+‐intercalation performance.

Graphene-modified nanostructured vanadium pentoxide hybrids with extraordinary electrochemical performance for Li-ion batteries

“…6b show that the calculated the two V 2 O 5 sheets. For the V 2 O 5 xerogel, the large amount of water may react with the lithium to form Li 2 O, which deteriorates intercalation performance 8 . Without water molecules to act as the pillars, the V 2 O 5 network in the disordered layer V 2 O 5 xerogel will collapse during annealing and become crystalline V 2 O 5 , which has much lower electrochemical performance.…”

“…The combination of the high specific capacity/energy and its abundance make V 2 O 5 a very attractive candidate for LIB applications. However, the high specific capacity/energy has not been realized in practical LIB applications [4][5][6][7][8][9][10] because of these three issues: (1) low electrical conduction, (2) slow lithium-ion diffusion and (3) irreversible phase transitions upon deep discharge. Like most metal oxides, V 2 O 5 has very low electronic conductivity due to its low d-band mobility 11 .…”

Materials Challenges Facing Electrical Energy Storage

“…Crystalline vanadium pentoxide, upon reaction with lithium, rapidly becomes disordered and exhibits typical capacitive-like discharge curves. Wang et al 21 have explored the morphology of nanovanadium oxides, and as shown in the Ragone plot in Figure 7, the electrochemical characteristics are strongly dependent on the morphology. (Ragone plots, in which the energy density-in Wh/kg-is plotted against the power density, in W/kg, are typically used to compare the performance characteristics of various energy storing devices.)…”

Synthesis of nanostructured solid-state phases of V7O16 and V2O5 compounds for ppb-level detection of ammonia

“…They are often formed as a layered structure, e.g. the well-known vanadium pentoxide V 2 O 5 [9] and can also exist in a more complex mixed-valence vanadium oxide form. The mixed valency occurs when oxygen vacancy defects are introduced to an ideal vanadium oxide structure.…”