Process for the preparation of metallic oxide bronzes and their use as electrode in electrochemical generators

摘要

Process for the preparation of metallic oxide bronzes, bronzes obtained by this process and their use in electrochemical generators. This process comprises the preparation of sol-gel solution of hydrated metallic oxides and is characterised in that an ion exchange of the sol-gel is carried out with a solution capable of contributing a cation of an alkali or alkaline-earth metal or of a transition metal to obtain a hydrated insertion compound of the type Axm'H2O. A thermal degradation of this insertion compound is then performed at moderate temperature for a sufficient period of time to obtain the said metallic oxide bronzes, preferably the temperature of thermal degradation is between approximately 300 and approximately 400 DEG C. The preparation of Na0.33V2O5 is described. The metallic oxide bronze obtained exhibits a very high anisotropy and excellent charge/discharge curves when used as cathode in electrochemical generators.