Study of the Lithium Intercalation/Deintercalation Processes into  V 2 O 5 by Linear Voltammetry at Slow Sweep Rates

Abstract

When T-300 was electrochemically etched at a constant current density (1.2 and 2.6 A cm-2), the voltage of the reaction was about 3 V at the beginning and gradually increased as the etching proceeded as shown in Fig. 7a. This is because the iR drop of the solution in microholes increases when the solution in the microholes are partially filled with gas evolved at the carbon fiber surface. The measured average slope in Fig. 7b and calculated conductivity (70 mS/cm) indicated that about hatf of the volume in the microholes is filled with gas during the etching process. The carbon fiber tips probably wet from the epoxy wall through the boundary between carbon fibers and epoxy resin. It is conceivable that the bubble size of the gas evolved at low current densities, is small, and tends to cover the whole surface of the carbon fiber tips. This might be the reason why a sharper tip is obtainable at low current densities.

A Novel Approach To Prepare Poly(3,4-ethylenedioxythiophene) Nanoribbons between V2O5 Layers by Microwave Irradiation

“…During the first cathodic scan, from the open-circuit voltage to 2.2 V vs Li/Li + , the crystalline V 2 O 5 undergoes a well-known phase transformation and the stabilization occurs after the third cycle (Figure a). The irreversible shift in the cathodic peak from 2.65 V (first cathodic scan) to 2.82 V (third and following cathodic scans) suggests that the structural change is permanent as reported elsewhere. − This type of voltammogram of crystalline V 2 O 5 is different from that of vanadium pentoxide xerogels V 2 O 5 · n H 2 O as reported by Livage and also Anaissi et al , since amorphous xerogels are known to exhibit enhanced electrochemical behavior in terms of faradic yields and reversibility. Further, the weak interactions between the interlamellar layers allow fast insertion of Li + ions between the ribbons rather than that in the channels of crystalline vanadium pentoxide .…”

Lithium Intercalation and Transport Behavior in a Ta[sub 2]O[sub 5] Film Fabricated by Pulsed Laser Deposition

“…Based on potential applications for solar cells, electrochromics, and lithium batteries, the lithium intercalation for a variety of transition metal oxides such as TiO 2 , WO 3 , Nb 2 O 5 , MoO 3 , and V 2 O 5 have been investigated in recent years. [1][2][3][4][5][6][7] These oxides with large bandgaps are chemically stable. The reaction for the electrochemical insertion/extraction of lithium ions into a host transition metal oxide MO y can be written as MO y ϩ x(Li ϩ ϩ e Ϫ ) o Li x MO y [1] where x can vary between 0 and 1.…”

Time-Dependent Mass Changes of Nanocrystalline TiO[sub 2] Thin Film Electrodes under Negative Bias in Propylene Carbonate

“…3 A number of inorganic oxides such as WO 3 , Nb 2 O 5 , and V 2 O 5 exhibit electrochromism. 2,[4][5][6] Although TiO 2 is probably the most widely studied transition metal oxide in photoelectrochemistry, [7][8][9][10][11] it has not been extensively investigated as an electrochromic material compared with WO 3 because of its long response time and low coloration efficiency. On the contrary, it is advantageous to study electrochromism with TiO 2 because of its slow coloration compared with WO 3 .…”