Engineering Triple‐Phase Interfaces around the Anode towards Practical Alkali Metal‐Air Batteries

Abstract

Alkali metal–air batteries (AMABs) promise ultrahigh gravimetric energydensities, while the inherent poor cycle stability hinders their practicalapplication. To address this challenge, most previous efforts are devoted toadvancing the air cathodes with high electrocatalytic activity. Recent studieshave underlined the solid–liquid–gas triple-phase interface around the anodecan play far more significant roles than previously acknowledged by thescientific community. Besides the bottlenecks of uncontrollable dendritegrowth and gas evolution in conventional alkali metal batteries, the corrosivegases, intermediate oxygen species, and redox mediators in AMABs causemore severe anode corrosion and structural collapse, posing greaterchallenges to the stabilization of the anode triple-phase interface. This workaims to provide a timely perspective on the anode interface engineering fordurable AMABs. Taking the Li–air battery as a typical example, this criticalreview shows the latest developed anode stabilization strategies, includingformulating electrolytes to build protective interphases, fabricating advancedanodes to improve their anti-corrosion capability, and designing functionalseparator to shield the corrosive species. Finally, the remaining scientific andtechnical issues from the prospects of anode interface engineering arehighlighted, particularly materials system engineering, for the practical use ofAMABs