Rechargeable lithium cells with modified vanadium oxide cathodes

Modified vanadium oxide has been prepared by melting V2O5 with additives of 3–3.5% of sodium orthosilicate at 690°C for 3 h followed by fast cooling to an ambient temperature. Charge–discharge characteristics of this oxide were studied as an active cathode material for lithium secondary batteries. The oxide undergoes irreversible transition to become essentially amorphous after first discharge to cut-off voltage of 2 V vs. Li, and then exhibits excellent rechargeability in the 1.5 to 3.9 V potential range. The coin type 2325 size secondary cells have been manufactured and tested with the modified vanadium oxide cathodes and Li–Al alloy anodes. Preliminary shallow cycling modifies the cellsʹ performance and allows to obtain rating capacity 50 mA h in the voltage diapason of 2.0–3.9 V with draining current 0.5 mA.