Boron-Doped Graphene as Anion-Trapping Reagent in Poly(ethylene oxide)-Based Solid-State Electrolyte

Although many protocols have been developed to enhance the ionic conductivity and lithium-ion transference numbers of the solid polymer electrolyte, it is still challenging to improve them simultaneously. Herein, we design and prepare boron-doped graphene (BG) as an anion trapper and blend it within a poly(ethylene oxide) (PEO)-based electrolyte. The well-dispersed BG sheets can reduce the crystallinity of PEO and afford numerous Lewis acid sites to effectively accelerate the dissociation of the lithium salt and trap the anions. Thus, the PEO-based electrolytes containing BG sheets exhibit a high ionic conductivity of 9.27 × 10^-5 S cm^-1 and lithium-ion transference number of 0.57 at 25 °C, which ensure the stable Li stripping/plating over 1000 h. The all-solid-state lithium-ion batteries assembled with the as-prepared electrolyte show excellent rate performance and cycling stability at 25 °C.