(658a) Oxidatively Stable, Water-Dispersible Polyaniline Derivatives for Flexible Energy Storage

Flexible energy storage provides an exciting alternative to conventionally inflexible batteries and capacitors. For example, flexible energy storage devices can be readily integrated into fabrics or paper. Conjugated polymers have been widely studied as electrodes for electrochemical capacitors and offer mechanical flexibility, but suffer from limitations in oxidative stability and capacity. Furthermore, processing conjugated polymers is often challenging because of their poor solubility in common solvents. This presentation highlights water-dispersible polyaniline:polyacid colloids that are oxidatively stable, high capacity, and energy dense. The polyacid stabilizes the fully oxidized pernigraniline salt form of polyaniline, which essentially doubles the reversible capacity of the electrode. The cycling behavior and materials properties of the polyaniline:polyacid electrodes are presented, as is their mechanism for enhanced stability. These electrodes maintain their reversible capacity of over 200 mAh/g (with respect to polyaniline mass) for over 800 cycles and are stable up to 4.5 V vs. Li/Li⁺. In contrast, homopolymer polyaniline has half the capacity (which it rapidly loses in less than 100 cycles) when cycled under identical oxidizing conditions.