Infra-red absorption spectra study of H-bonding and of metal-element bonding

Alkali (Li/Na/K) metal anodes (AMAs), because of their remarkably high energy density and low redox potential, are considered as the most promising anodes for next-generation high-energy battery systems. Nevertheless, high reactivity and uncontrollable volume change of metal anodes during plating/striping inevitably generate dendritic metal and unstable solid electrolyte interphase, inducing low Coulombic efficiency, inferior cycling stability and even safety issues. Architecture design is emerged as an effective approach to address these fatal issues and plenty of attempts have been conducted so far. Instead of simply summarizing the structure-designing strategies to modify AMAs, the review is dedicated to overviewing and categorizing the strategies of architecture design towards the challenges of AMAs by their fundamental design principles from the perspective of electrochemical reaction. Besides, the similarities and differences of three types of alkali metals, in terms of mechanical and chemical properties, have been systematically discussed. Finally, we overviewed the existing challenges, perspectives on further development direction, and outlook for practical applications for AMAs.