Crosslinked Electroactive Polymers Containing Naphthalene-Bisimide Redox Centers for Energy Storage

Electroactive polymers represent an attractive alternative to the current inorganic-based materials for electrochemical energy storage systems as they allow eliminating the need for expensive transition and rare-earth metals. This is particularly relevant for all polymers that can be obtained by direct oxidative polymerization of the corresponding monomer. We investigate the energy storage properties of electroactive polymers based around the concept of attaching a redox-active core to a highly electronically conductive backbone. In this paper we describe the synthesis and characterization of physical and electrochemical properties of the naphthalene-bisimide (NPbIm) core coupled with Poly(3,4-ethylenedioxythiophene) (PEDOT). We find that the composite polymer shows two distinct monoelectronic redox peaks attributed to the reduction of naphthalene-bisimide to radical anion and dianion near 2.5 V vs. Li+/Li, as well as the standard PEDOT electrochemistry. The polymer shows excellent charge retention capabilities with more than 90% capacity maintained after 1000 cycles as an electropolymerized film. Composite electrodes prepared with 73 wt% of powders of active material exhibit good high rate capabilities by retaining more than 70% of the original capacity measured at C/10 when cycled at 1C rate. To the best of our knowledge this is one of the highest performances so far reported for organic materials.