In summary, these two works demonstrate that the solvation structure and the stable SEI layer play a critical role in the electrochemical behavior of AFSMBs. By adjusting the electrolyte salt or solvent, the solvation structure can be effectively regulated and the inorganic-rich, robust SEI with high ionic conductivity can be constructed, in turn achieving the favorable electrochemical performance. The design strategy for refining the electrolyte solvation structure and interfacial chemistry provides valuable insight and stimulates new activity in the future research and development of high-energy batteries for sodium and other rechargeable systems (e.g., rechargeable Li/K batteries).