Conductive Polymer/Transition Metal Oxide Hybrid Materials for Lithium Batteries

Organic-inorganic hybrid materials were synthesized for use of lithium battery electrode by two strategies: 1) core-shell strategy for tri-dimensional transition metal oxide and 2) intercalation strategy for bi-dimensional (lamellar) transition metal oxide. We choose conductive polymers as an organic component for high electric conductivity and 3d-transition metal oxides as an inorganic counterpart for large capacity and processibility. Polypyrrole/maghemite and poly(3,4-ethylenedioxythiophene) (PEDOT)/vanadium pentoxide hybrids will be presented and compared with their pristine materials for core-shell and intercalation strategies, respectively. Polypyrrole/maghemite showed an enhanced electrochemical reversibility and capacity up to ∼270 mAh/g in the potential range between 1.3 and 4.3 V vs. Li at 8 mA/g. PEDOT/vanadium pentoxide also exhibited improved reversibility and capacity up to ∼330 mAh/g at 15 mA/g between 2.0 ∼ 4.4 V vs. Li on the second discharge. XRD, IR, electron microscopy, XPS and Xray absorption spectroscopy were used to characterize the samples, and to examine oxidation state of the transition metals, doping character of the polymer and the nature of interaction between the polymer and the transition metal oxides.