Electronic and electrochemical properties of NaxCoO2−y cathode

Abstract The discharge curve of a Na/liquid electrolyte/Na 0.70 CoO 2−y cell has been studied in relation with the conditions of preparation of the cathode material. It has been shown that the starting open citcuit voltage is a linear function of the electronic carrier concentration. The amount of sodium which can be introduced electrochemically into Na 0.70 CoO 2−y is dependent on the initial concentration of electronic carriers in this phase. The investigation of the electric properties of the cathode material after electrochemical intercalation of sodium shows differences between the transport properties of intercalated cobalt bronze and those of starting material.