The　electrochemical　instability　of　traditional　ether-based　electrolytes　poses　a　challenge　for　their　use　in　high-voltage　lithium　metal　batteries.　Herein,　a　synergetic　optimization　strategy　was　proposed　by　introducing　an　additive　with　a　strong　electron-withdrawing　group　and　significant　steric　hindrance—isosorbide　dinitrate　(ISDN),　reconstructing　the　solvation　structure　and　solid　electrolyte　interphase　(SEI),　enabling　highly　stable　and　efficient　lithium　metal　batteries.　We　found　that　ISDN　can　strengthen　the　interaction　between　Li+　and　the　anions　of　lithium　salts　and　weaken　the　interaction　between　Li+　and　the　solvent　in　the　solvation　structure.　It　promotes　the　formation　of　a　LiF-rich　and　LiNxOy-rich　SEI　layer,　enhancing　the　uniformity　and　compactness　of　Li　deposition　and　inhibiting　solvent　decomposition,　which　effectively　expands　the　electrochemical　window　to　4.8　V.　The　optimized　Li||Li　cells　offer　stable　cycling　over　1000　h　with　an　overpotential　of　only　57.7　mV　at　1　mA　cm−2.　Significantly,　Li||3.7　mA　h　LiFePO4　cells　retain　108.3%　of　initial　capacity　after　546　cycles　at　a　rate　of　3　C.　Under　high-loading　conditions　(Li||4.9　mA　h　LiNi0.8Co0.1Mn0.1O2　full　cells)　and　a　cutoff　voltage　of　4.5　V,　the　ISDN-containing　electrolyte　enables　stable　cycling　for　140　cycles.　This　study　leverages　steric　hindrance　and　electron-withdrawing　effect　to　synergistically　reconstruct　the　Li+　solvation　structure　and　promote　stable　SEI　formation,　establishing　a　novel　electrolyte　paradigm　for　high-energy　lithium　metal　batteries.　©　2025