Metal–Organic Coordination Enhanced Metallopolymer Electrolytes for Wide‐Temperature Solid‐State Lithium Metal Batteries

The practical application of polymer electrolytes is seriously hindered by the inferior Li+ ionic conductivity, low Li+ transference number (tLi+), and poor interfacial stability. Herein, a structurally novel metallopolymer is designed and synthesized by exploiting a molybdenum (Mo) paddle‐wheel complex as a tetratopic linker to bridge organic and inorganic moieties at molecular level. The prepared metallopolymer possesses combined merits of outstanding mechanical and thermal stability, as well as a low glass transition temperature (Tg 5.0 V). This study presents a unique MPE design based on metal–organic coordination enhanced strategy, providing a promising solution for developing wide‐temperature solid‐state LMBs. A structurally novel polymer crosslinked by metal–organic coordination units (defined as metallopolymer) is designed and prepared to develop high‐performance metal–organic coordination enhanced metallopolymer electrolytes (MPEs). By exploiting a Mo paddle‐wheel complex as a tetratopic linker, the organic and inorganic moieties of polymer skeleton are integrated at molecular level, without phase separation and local inhomogeneity. The coordinatively unsaturated Mo≡Mo units in Mo(II) paddle wheel complexes can serve as Lewis acid sites to effectively bind to bis(fluorosulfonyl)imide anions (FSI−), increase Li+ flux, and facilitate FSI− decomposition, resulting in uniform Li+ concentration gradients and the formation of stable fluorinated interfaces.