Atomistic investigation of the nanoparticle size and shape effects on ionic conductivity of solid polymer electrolytes

•We conduct molecular dynamics simulations of PEO/LiClO4–TiO2 electrolyte.•Nanofillers enhance the dissociation of Li salt and mobility of Li ions.•Size and surface functionalities of the nanofillers play a role in ion transport.

Adding nanoparticle fillers is a potential route to enhance room temperature ionic conductivity of solid polymer electrolytes. In this work, we use molecular dynamics simulation to elucidate the role of nano-scale filler size and shape on ionic conductivity. Our key conclusions are that the addition of nanofillers can affect the salt dissociation, lithium-ion mobility, and the dynamics of polymer chains. The repulsive nanofillers of different sizes appear to suppress ion-cluster formation and enhance lithium ion mobility. Smaller size nanofillers are found to be comparatively more effective in increasing the mobility of lithium ions while shape effects appear to be insignificant.