PNNL

Abstract

Metal (M)-oxygen (O2) batteries (MOBs) are great candidates for the next-generation energy storage systems due to their high safety, low cost, environmental friendliness and especially a high volumetric energy density. However, during oxygen reduction process in metal-oxygen batteries (MOBs), the solid discharge products can deposit/accumulate, clog the pores of the air electrode, and block the transport of oxygen and various ion species in aqueous or non-aqueous electrolytes, therefore lead to increased impedance and shortened cycle life of MOBs. Herein, we demonstrate that a three-dimensionally ordered macroporous (3DOM) air electrode can largely alleviate detrimental effect due to the accumulation of reaction product during discharge process, facilitate the smooth flow of active species including oxygen and ions in air electrode during the charge/discharge process of MOBs, including non-aqueous lithium-oxygen batteries and aqueous zinc-oxygen batteries. As a result, 3DOM structured air electrode can be used as an effective approach to reduce overpotential and impedance of MOBs, therefore enhance their capacity and cycle life.