SU617490A1 - Electrolyte for electrochemical production of n-phase of oxygen vanadium bronzes - Google Patents

Description

100 A / cm. The process is conducted in an atmosphere of air.

According to x-ray and chemical analyzes, a single-phase product of lix vanadium bronze of composition LixVsOs is obtained at the cathode, where X is 0.92.

Example 2. A mixture of 100 g of sodium carbonate (NagCOs) with 180 g of vanadium pentoxide (VgOs) is melted at a temperature of 635 ° C and electrolysis is carried out as in Example 1. According to X-ray chemical analysis, a single-phase product of sodium vanadium bronze of composition NaxV205 is obtained at the cathode, where X 0.7.

From the proposed electrolyte electrolysis receive a pure single-phase proCathodic

Chemical analysis of the product potential,

LI-23.30 mmol / l

V (V) -23,06 mmol / l

V (IV) -23.01 mmol / l

Li-25.55 mmol / l V (III) -25.38 mmol / l

Are present; V (V), V (IV), LI, K, Cl

Present: V (V), V (IV), LI, K, CI

Present: V (II), V (1V), LI, K, CI

Thus, in addition to chlorine ions, the α-phase of oxygen vanadium bronze, it contains self-contained phases (orthovanalat lithium), as well as substances that include potassium and unidentified compounds. These impurities can not be separated from the main product (lithium vanadium bronze) by simple methods.

The data of chemical and phase X-ray analyzes on the purity of the product, obtained electrolytically from the proposed pure oxide electrolyte are given in table. 2

From the data given in table. 1 and 2, it can be seen that the increased purity of the product obtained, as well as the oxide electrolyte, allows vanadium bronze to creep without the presence of impurities of compounds, which was not achieved in the chloride melt.

The product of oxygen vanadium bronze of the type MxV2O5, which does not contain impurities orthovanadates and lower oxides. In addition, carrying out electrolysis in the proposed electrofolder in an open air atmosphere greatly simplifies the technology of the synthesis of a bopz.

Cathodic sediment obtained from a known electrolyte, as shown by chemical

and phase x-ray analyzes, is a mixture of 7-phase lithium vanadium bronze and products released in the composition of LiVO2, LiZVO, and also includes an impurity of chlorine and potassium, depending on

from cathode potential tab. one).

Table 1

Phase X-ray analysis of the product

LiV2O5 Y-phase

Ligvo

LiVO-i LiVOi

Substances not identified

LiVjOj f-phase and the same products as at 950 V

LiVOj and the same products as at 950 V

The specified ingredient intervals (35-55 mol% M2O, 45-65 mol% V205) are at the same time the concentration limits of the y phase of oxygenated vanadium bronzes in the electrolyte components. Electrolyte containing less than 45 mol. % V2O5, has a high melting point (up to 1200 ° C) and vanadium pentoxide in the melt undergoes strong dissociation to V2O4, which causes a decrease in current efficiency to zero due to a large fraction of the electronic component. In the molten electrolyte containing more than 65 mol. % VzO, the f-phase separation of the oxygen vanadium bronze also does not occur for the reason indicated above, i.e. the current output drops to zero.

Thus, the proposed electrolyte allows to obtain pure β-phases of acid Table 2

ferrous vanadium bronzes, as well as significantly simplify the process of electrolysis due to the absence of the need to work in an inert atmosphere.

Claims (1)

Invention Formula The electrolyte for the electrochemical preparation of 7-phase oxygen vanadium bronze type MxVsOs, where M is an alkali metal, and 0, containing the compound Vanadium and a compound of the corresponding alkali metal, characterized in that, in order to increase the purity of bronze, it contains vanadium pentoxide as the compound of vanadium, and alkali metal oxide as the compound of alkali metal in the following ratio of components, mol. %: Vanadium thioxide 45-65 Alkali metal oxide M2035-55