Single-ion diblock copolymers for solid-state polymer electrolytes

- We disclose a convenient 3 steps synthesis for high performance solid electrolyte.
- The single-ion electrolyte design has been optimized to afford the mechanical and ion transport performances.
- Single-ion electrolytes containing BF3 have attractive ionic conductivities as high as 0.02 mS/cm at room temperature.
- The single-ion electrolyte promotes the formation of a stable SEI.

Li-ion battery technology is considered as the most efficient solution for the electrochemical energy storage. While standard liquid electrolyte - based configurations provide best performances, solid state electrolytes are developed as a safer alternative. Herein, we discuss a three step synthesis procedure of self-doped solid block copolymer electrolyte, combining a single-ion poly(lithium methacrylate-co-oligoethylene glycol methacrylate) ion conducting block (P(MALi-co-OEGMA)) and a structuring polystyrene block (PS). The macromolecular design allows the formation of a self-standing film with excellent mechanical properties provided by the PS anchoring nanodomains while attaining attractive ionic conductivities of up to 0.02 mS/cm at room temperature. Moreover, the single-ion configuration based on polyanionic backbone affords high transference numbers, close to unity, and alleviates the power limitation encountered in salt-doped solid polymer electrolyte (SPE). The electrolyte exhibits a wide electrochemical stability window up to 4.5 V vs. Li+/Li and promote the formation of stable interfaces at the electrodes.