The effect on the enhancement of the charge/discharge behavior of electrodeposited lithium metal on various substrates with CO, was investigated in LiClO4/propylene carbonate electrolyte. The lithium cycleability was enhanced with CO2 addition to the electrolyte solution when using nickel and titanium substrates, whereas no apparent enhancement was observed with copper and silver substrates. The results obtained from voltammetry indicated that the reduction of CO2 did not occur on nickel and titanium, but on copper and silver. It is suggested that the enhancement with CO2 addition is effective with the substrates which do not reduce CO2 in the electrolyte before lithium deposition.