Large Enhancement of Ionic Conductivity in Composite Polymer Electrolyte with Well-Aligned Ceramic Nanowires

Solid Li-ion electrolytes are considered as an alternative to replace conventional liquid electrolytes for next-generation high-energy and safe batteries. However, the low ionic conductivities of solid electrolytes limit their applications. Inorganic nanoparticles have been widely used to incorporate into host polymers to obtain solid composite polymer electrolytes with improved electrochemical performance and mechanical strength. Here for the first time, we demonstrated composite polymer electrolytes with well-aligned inorganic nanowires. The results show that random nanowires in composite polymer electrolyte introduce larger enhancement of ionic conductivity than nanoparticles. The most exciting result is that the ionic conductivity of composite polymer electrolyte with aligned nanowires is about 10 times higher than that with randomly dispersed nanowires. This is because that an aligned nanowire offers a continuous fast ion pathway without crossing junctions like those between nanoparticles or between random nanowires. The nanowire interfacial conductivity has an impressive liquid-like conductivity of 1.26×10-2 S cm-1 at 30 °C.