CoCO3 from one-step micro-emulsion method as electrode materials for Faradaic capacitors

Abstract Faradaic capacitor (FC) has been widely investigated during the past few decades, and dozens of prototypes have been proposed. However, it has not reached its full potential. In this work, we demonstrate a kind of FC comprising of a CoCO3 electrode. Synthesized through a micro-emulsion route, such CoCO3 shows low crystallinity and porous wool-ball structures stacked by needle-like individuals. It shows desirable electrochemical properties in terms of excellent high-rate performance and high reversibility. Also, it could deliver a capacitance of 440 F·g−1 at 1 A·g−1, and shows no capacitance decay after 1000 cycles. Since metal carbonate is capable of delivering good electrochemical performances and its preparation is easier and more cost-efficient, it should be a feasible candidate for electrode material of FC.