Electronic Synergy of Atom Sites and Adjacent Defects for High-Voltage Sodium-Ion and Zinc-Air Batteries.

The Na transmission with reduced voltage polarization of the anode at high current densities and increased capacities are major challenges for sodium ion batteries (SIBs), which need adaptive electrolytes along with incorporation of conductive metal-atom sites for intrinsic electric field. Interphase reconstruction for both cathode-electrolyte interphase (CEI) and solid-electrolyte interphase (SEI) plays crucial role for high-voltage SIBs. SIBs and zinc-air batteries (ZABs) require material advances and knowledge of atomic-scale performance impacts. Single-atom strain and single/dual atom incorporated hard carbon with C/N defected graphene surface plays major role in distribution of electrons around atom sites to accelerate pathway via synergistic effects. Herein, this review focuses on effect of single-metal-atom and defect-atoms incorporation with possible limitations, and potential electrode materials to achieve long-cyclic stability and faster kinetics. Key concepts in this context of SIBs are based on the SEI and intrinsic conductivity optimization methods, wherein the role of single-atom-based anodes is defined. Additionally, features of ZABs at sub-zero temperatures are also included to emphasize the possible translational impact on single-atom-based electrodes. Finally, Na storage mechanism on anode and role of ex situ/in situ techniques to reveal the unknown to impact on the recent trends. Finally, a summary is provided on the challenges and trends in improving SIBs and ZABs, pointing out the main obstacles and opportunities to support their fast development and wider use.