Materials & Design (Jul 2020)
Contactless electric–field driven Z-alignment of ceramic nanoparticles in polymer electrolyte to enhance ionic conductivity
Abstract
The contactless electric–field accomplishes particles alignment in solution allowing free solvent evaporation without electrochemical decomposition. Herein the nanoparticle Li1+xAlxGe2-x(PO4)3(LAGP) Z-direction (out-of-plane) alignment was driven by a contactless electric field within a cross-linked solid electrolyte of poly(ethylene oxide)/poly(ethylene glycol) diacrylate/lithium bis(trifluoromethylsulfonyl)imide (PEO/PEGDA/LiTFSI). The alignment and chain formation of nanoparticles was verified by scanning electron microscope combining with energy dispersive X-ray spectrometry. Benefiting from this Z-direction alignment, LAGP/PEO/PEGDA/LiTFSI membrane possesses enhanced ionic conductivity and improved flexibility. With 20 wt% LAGP loading, 2.7 times ionic conductivity was achieved in the Z- direction and 1.6 times elongation at breaking was obtained along the membrane surface after alignment. This contactless electrical field method is a new strategy to prepare polymer composite membrane with anisotropic property from solvent-containing system.