Performance of “Polymer-in-Salt” Electrolyte PAN-LiTFSI Enhanced by Graphene Oxide Filler

Exploring solid state electrolytes with high ionic conductivity and good electrochemical stability is of prime importance for the development of safe batteries. In this study, we prepare a high-performance "polymer-in-salt" solid polymer electrolyte (SPE) by using polyacrylonitrile (PAN) as a host polymer, bistrifluoromethanesulfonimide lithium salt (LiTFSI) as an electrolyte salt, and different loading graphene oxide (GO) as a nano-filler. PAN-LiTFSI electrolyte filled with 0.9 wt% GO nanosheet exhibits an ionic conductivity of 1.1 × 10−4 S cm−1 at 30°C, which is almost one order of magnitude higher than that of the filler-free one. In addition, the anodic potential and the lithium ion transference number also increase to 5 V and 0.4, respectively. The enhancement on ionic conductivity is attributed to a 3D fast ion transport network constructed by GO nanosheets and a further decoupling of ion transport from segmental dynamics.