Enhancement of Lithium Anode Cyclability in Propylene Carbonate Electrolyte by CO 2 Addition and Its Protective Effect Against H 2 O Impurity

Abstract

The charge‐discharge behavior of a lithium metal anode in propylene carbonate (PC) electrolyte containing added was investigated using in situ ac impedance measurements during galvanostatic cycling. In PC electrolyte with , the anode's cycle life was twice as long and its charge transfer resistance was smaller than in the same electrolyte without . These enhancements are observed only when lithium is electrodeposited in the presence of on nickel substrate; the enhancement does not occur when lithium is deposited without and is cycled with . Even large amounts of in the electrolyte during cycling do not adversely affect the cycle life enhancement by . The enhancement seems to be due to products formed by reaction of lithium with on the electrodeposited lithium surface.