Conducting Composite Polymer-Based Solid-State Electrolyte with High Ion Conductivity via Amorphous Condensed Structure and Multiple Li+ Transport Channels.

Abstract

Traditional PEOelectrolyte has high crystallinity which hinders the transmission of Li+, resulting in poor ion conductivity and complicated processing technology. Herein, a polymer electrolyte (p-electrolyte) with a wide electrochemical window and high ionic conductivity is designed, which possesses an amorphous condensed structure. The amorphous structure provides fast transport channels for Li+, so the p-electrolyte possesses an electrochemical window of 4.2V, and high ionic conductivity of 1.58 × 10-5Scm-1 at room temperature, which is 1-2 orders of magnitude higher than that of traditional PEO electrolyte. By using the designed polymer electrolyte as the foundation, an in situ curable composite polymer electrolyte (CPE-L) with multiple Li+ transport channels is elaborately constructed. The Cu-BTC MOF stores abundant Li+, which is introduced into the p-electrolyte. The rich unsaturated Cu2+ coordination sites of Cu-BTC can anchor TFSI- to release Li+, and the pore structure of Cu-BTC MOF cooperates with LLZTO nanoparticles to provide multiple fast transport channel for Li+, resulting in remarkable ionic conductivity (1.02 × 10-3Scm-1) and Li+ transference number (0.58). The Li||CPE-L||Li symmetric battery cycles stably for more than 700h at 0.1mAcm-2, while the specific capacity of full battery is ≈153mAhg-1 (RT, 0.2C).