γ-Fe2O3 nanoparticles encapsulated in polypyrrole for quasi-solid-state lithium batteries

Abstract

Nano-sized γ-Fe₂O₃ was prepared by a minor modification method in combination with high energy ball milling, and a core–shell structure was designed using polypyrrole (PPy) by chemical polymerization. The structure and morphology of core–shell γ-Fe₂O₃–PPy were investigated by XRD, FT-IR, SEM, and TEM. For solid-state batteries, PPy–Fe₂O₃ cells were fabricated with a gel polymer electrolyte prepared by an electrospinning process. The charge and discharge gravimetric capacities of all-solid-state batteries at the first cycle are 400 and 421 mA h g⁻¹ and 220 and 221 mA h g⁻¹ for 0.1 and 1 C-rates, respectively, which correspond to 760 and 800 mA h cm⁻³ and 418 and 420 mA h cm⁻³ of volumetric capacity.