Lithium intercalation and conduction in Fe-containing tantalum oxide films synthesized with an atmospheric pressure plasma jet

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

“…A transparent ion-conducting layer (i.e., electrolyte) is usually placed in the middle location of the ECD and connects the EC and ion storage films [28]. FeTa x O y C z or Li α FeTa x O y C z films are pre-deintercalated in a 1-mol/L LiClO 4 -PC electrolyte with a static potential at − 1.25 V for a duration of 10 s prior to Li + ion intercalation and deintercalation to eliminate the effects caused due to excesses of Li + ions.…”

“…Therefore, the APPJsynthesized Li α FeTa x O y C z film is a potential Li + ionic conductor layer for ECDs. For both Li + ions and electrons intercalated into FeTa x O y C z or Li α FeTa x O y C z films, Fe 3+ or Ta 5+ or Li 2+ ions turn to Fe 2+ or Ta 4+ or Li + ions and polarize their surrounding lattice to deliver small polarons, as shown in the following reactions [28,43]:…”

“…Li + ionic conductivity is up to 3 × 10 −10 S/cm for TaO x films that is just about 1/2 times lower than H + protonic conductivity that is up to 6 × 10 −10 S/ cm [24]. Hence, several oxides such as lithium oxide (LiO x ) [25], titanium oxide (TiO x ) [26], zinc oxide (ZnO x ) [27], and iron oxide (FeO x ) [28] films have been added into TaO x thin films to increase Li + ionic conduction in TaO x films. In this study, LiO y C z and FeO y C z are both co-synthesized into Ta x O y C z films by a nonequilibrium plasma polymerization method at atmospheric pressure and room temperature (23°C) with an APPJ for a short exposed duration of 38-41 s. In the last two decades, nonequilibrium atmospheric pressure plasmas have been examined mostly to deposit thin films.…”