Nafion based surface protective layer for lithium metal in lithium oxygen batteries

Abstract

Constructing a sustainable surface protection layer for lithium metal anode is a critical unsolved challenge to improve the long term cycle performance of lithium oxygen (Li O 2 ) batteries. Recently, a variety of approaches have been proposed for lithium metal surface protection. However, the inadequate evaluation of the stability of the lithium metal protective layer is a shortcoming in previous reports. Therefore, in this study , the Nafion based composite layer (NCL) as a electrochemically and chemically stable protective layer for lithium metal in Li O 2 batteries was fabricated. Simultaneously, the outperformance of electrochemical and chemical stability of NCL in comparison wi th reported lithium metal protective materials was investigated. Li O 2 batteries using NCL coated lithium metal exhibited good reversible oxygen gas in discharge and recharge processes with the mini m um parasitic reactions from spontaneous reactions between reactive oxygen species and protective materials. NCL also exhibited superior electrochemical stability which was verified with not only Li stripping and plating test but also a severe operating condition with high current and capacity values in large scale Li O 2 pouch cell s .