Conductive nonconjugated radical polymer as high capacity organic cathode material for high-energy Li/Na ion batteries

A nonconjugated radical polymer poly (4-glycidyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl) (PTEO) is explored as organic cathode material in Li and Na ion batteries for the first time. The PTEO exhibits a high electrical conductivity of 0.13 S m(-1), far exceeding other organic cathode materials ranging from 10 to 10 to 10(-5) S m(-1). It offers high redox potentials with platueas at similar to 3.6 V vs. Li+/Li and 3.3 V vs. Na +/Na, respectively. The PTEO cathode with only 30 wt% carbon additive agent delivers a capacity of over 200 mAh g(-1) and energy density of more than 500 Wh kg(-1) for both Li/Na ion batteries. Reaction mechanism of the PTEO proceeds through the neutral state nitroxide radical (N-O.) to oxoammonium cation (+N=O) and the aminoxy anion (N-O center dot). The PTEO is the only radical polymer that can deliver a capacity over 200 mAh g(-1) for organic cathodes with no more than 50% carbon additive agent, making it a promising organic cathode material for Li/Na ion batteries.