Realizing High-Flux Li plus conduction and stable solid electrolyte interface by Iodine- and Amino-Functionalized MOFs doping in Solid-State electrolytes

Metal organic framework (MOFs) have been extensively studied as polymer solid-state electrolytes (SSEs) fillers owing to their structural diversity and controllable synthesis advantages. However, the low ion conductivity and unstable interfaces with Li anode inducing high interfacial impedance and lithium dendrite growth that limit their practical application. Herein, functionalized MOFs, which introduce substituted ligands with different properties, addresses the issues of low ion conductivity and growth of Li dendrites. I and NH2-modified functionalized MOFs were selected for the construction of high-performance SSEs. The NH2 group in the CuBTC-NH2- I3 framework promotes LiTFSI dissociation and enhances ionic conductivity. Furthermore, the released I- reacts with Li+ to form high-performance LiI-rich solid electrolyte interphase (SEI), which facilitates uniform Li+ deposition and inhibites the growth of Li dendrites. Moreover, the structure-performance relationship of CuBTCNH2-I3 electrolyte was explored through experiments and theoretical calculations, offering insights into both its ion transport mechanism and SEI formation mechanism. This dual synergistic functionalization of MOFs presented here offers a novel approach to designing structurally functional SSEs.