Enhanced lithium intercalation and conduction in LiαFeTaxOyCz films by the addition of lithium oxides with an atmospheric pressure plasma jet

Abstract

An enhancement of lithium ionic intercalation and conduction performance of lithiated-organo-iron-tantalum oxide (LiαFeTaxOyCz) films has been accomplished by the addition of organo-lithium oxides (LiOyCz) into organo-iron-tantalum oxide (FeTaxOyCz) films using an atmospheric pressure plasma jet (APPJ) at various mixed concentrations of lithium tert-butoxide [(CH3)3COLi] and tantalum ethoxide [Ta(OC2O5)5] precursors. The rapid deposition of LiαFeTaxOyCz films onto polished stainless steel substrates at short exposed durations of 38–41 s with an APPJ has been investigated. The APPJ-polymerized LiαFeTaxOyCz films have noticeable Li+ ionic intercalation/deintercalation performance at 200 reversible cycles in a 1-M LiClO4-propylene carbonate electrolyte as analyzed by both potential sweep and potential step in situ Li+ ionic intercalation. The Li+ ion intercalated and deintercalated charges are significantly improved from 5.70 and 5.20 mC/cm2 for FeTaxOyCz film to 8.11 and 7.51 mC/cm2 for LiαFeTaxOyCz films, respectively. The Li+ ionic conduction performance of FeTaxOyCz film is slightly enhanced from 107 × 10−10 to 118 × 10−10 S/cm for LiαFeTaxOyCzfilm, as verified by electrochemical impedance spectroscopy in the devices of polyethylene terephthalate (PET)/indium tin oxide (ITO)/NiOx/FeTaxOyCz/NiOx/ITO and PET/ITO/NiOx/LiαFeTaxOyCz/NiOx/ITO.