Nanocomposites for Lithium-Ion Battery Anodes Made of Silicon and Polyaniline Doped with Phytic Acid

Abstract

The properties of lithium-ion battery (LIB) anodes fabricated from nanoscale silicon Si and polyaniline (PANI) as a binder are reported. PANI is prepared by in situ polymerization of aniline in the presence of phytic acid, which serves both as dopant and as a gel-forming agent. PANI pellets obtained by dry compression are used to investigate the morphology and to measure the resistivity of PANI and Si/PANI composites. The anodes are fabricated using the slurry technique. Their properties as a function of precursor ratio are studied in the half-cell cells by charge–discharge characteristics, cyclic voltammetry, electrochemical impedance spectroscopy and cyclic lifetime. It is shown that stable cycling (>350 cycles at a current of 300 mA g⁻¹) is inherent only to thin Si/PANI layers with composite loading <0.7 mg cm⁻². The discharge capacity in this case is as high as 500–800 mAh g⁻¹.