One-Step In Situ Polymerization: A Facile Design Strategy for Block Copolymer Electrolytes

Angew Chem Int Ed Engl. 2023 Feb 20;62(9):e202213606. doi: 10.1002/anie.202213606. Epub 2023 Jan 18.

Abstract

To optimize the rapid transport of lithium ions (Li+ ) inside lithium metal batteries (LMBs), block copolymer electrolytes (BCPEs) have been fabricated in situ in LMBs via a one-step method combining reversible addition-fragmentation chain transfer (RAFT) polymerization and carboxylic acid-catalyzed ring-opening polymerization (ROP). The BCPEs balanced the Li+ coordination characteristics of the polyether- and polyester-based electrolytes to achieve a rapid Li+ migration in the SPEs. The carboxylic acid played a dual role since it both catalyzed the ROP and stabilized the interface. Furthermore, the in situ assembly of LMBs did effectively enable an efficient intercalation/de-intercalation of Li+ at the electrode/electrolyte interface. The in situ assembled Li/BCPE4/LFP exhibited high-capacity retention of 92 % after 400 cycles at 1 C. The one-step in situ fabrication of BCPEs provides a new direction for the design of polymer electrolytes.

Keywords: Block Copolymers; Electrolytes; Lithium Metal Batteries; One-Step Processes; in Situ Polymerization.