Joint Centers of Excellence Program

Supercapacitors — Viologens as Organic Redox Centers for Increased Charge Storage Capacity (Domain 2, Project 1)

Supercapacitors are energy storage devices that bridge the gap between conventional capacitors and rechargeable batteries. They have the highest available capacitance per unit volume and the greatest energy density of all capacitors. They support up to 12 F/1.2 V, with capacitance values up to 10,000 times that of electrolytic capacitors. While existing supercapacitors have energy densities that reach approximately 10% of conventional batteries, their power density is generally 10 to 100 times greater, which results in much shorter charge/discharge cycles than a battery is capable of, and a greater tolerance for numerous charge/discharge cycles. One of the promises of supercapacitors is their potential to reduce the size—and therefore the cost—of hybrid vehicle batteries. Market researchers predict that the supercapacitor market will grow rapidly in the coming years, mainly driven by the automotive and transportation sector, as well as by applications in renewable energy, consumer electronics, and industrial power management. In this work, we propose to (i) utilize viologen-based compounds and polymers to coat activated carbon electrodes for use in an organic supercapacitor. Viologens are well known to undergo a large number of oxidation/reduction cycles, and are thus expected to (ii) contribute significantly to the lifetime and cyclability of the device. The ultimate goal of this project is (iii) the development of the next-generation supercapacitors that are compatible with current electrically powered devices and that can be easily adapted to meet the requirements of future applications.