Overcoming Interphase‐Dependent Li ⁺ Transport via Tridentate Coordination Engineered Solvation Sheath

ABSTRACT Gel polymer electrolytes (GPEs) are pivotal for advanced lithium metal batteries (LMBs) as they can combine high ionic conductivity and enhanced safety. However, their commercialization is hindered by an unresolved kinetic limiting step derived from the dynamic coupling among bulk diffusion, desolvation, and interphase transport. Here, a novel strategy is proposed to regulate the denticity of TFSI − coordination from monodentate to tridentate to decouple these processes. The intrinsic chemistry of the solid‐electrolyte interphase (SEI) rather than bulk ionic conductivity or desolvation energy is identified as the predominant factor governing cyclability. Crucially, the tridentate coordination strategically elevates the reductive priority of the normally stable TFSI − anions over the more labile solvents, thereby superseding the intrinsic tendency and ensuring the in situ formation of an inorganic‐rich SEI dominated by LiF and Li 2 O. This robust SEI underpins exceptional interfacial stability, enabling 92.7% of its original capacity after 720 cycles at 1 C in LiFePO 4 //Li cells. The generality of this approach is also validated in LiNi 0.6 Co 0.2 Mn 0.2 O 2 ‐based cells, which achieve stable cycling over 270 cycles at 25°C and over 150 cycles at 60°C. The fundamental insight into the rate‐limiting interfacial coupling and the tridentate‐coordination strategy collectively establish a new paradigm for electrolyte design.