Hairy Nanoparticles Improve Cycling Stability of a Solid-State Polymer Electrolyte*

The development of solid electrolytes that prevent dendrite growth while providing the desired level of conductivity is essential for improving the cycling stability of solid-state Li metal batteries. In this paper, we report the synthesis of single Li-ion conducting hairy nanoparticle (NP) materials that improved the cycling stability of a model solid polymer electrolyte without significant reduction in its conductivity. Several characterization techniques including broadband dielectric spectroscopy (BDS), differential scanning calorimetry (DSC), small angle X-ray scattering (SAXS), transmission electron microscopy (TEM), shear rheology are used to study the properties of polymer composites with added hairy NPs. It is found that the addition of hairy NPs stabilizes the Li/electrolyte interface and improves both the Li+ transport number and the mechanical properties of bulk composites, all of which contribute to homogenous Li plating and stripping. Based on the discovered ability of hairy NPs to influence bulk and interfacial properties of electrolytes, their use as additives is expected to be equally effective in reducing dendrite formation in diverse electrolytes.