Electric Double-Layer Capacitors (EDLC) Supercapacitors

KEMET, a YAGEO group company, offers a wide portfolio of supercapacitors that store electric energy via an electric double layer at an interface between an electrolyte and a solid electrode. The solid electrode is primarily carbon with a high amount of surface area. The combination of surface-mount and thin electric double layer thickness determines high capacitance capability. High capacitance, fast charging, and unlimited charge/discharge cycling make supercapacitors widely used in industry.

KEMET is the only producer of supercapacitors using aqueous electrolyte solutions in the world. Aqueous electrolytes are highly conductive, low in environmental impact, non-toxic, and non-flammable, yielding strong performance and safety credentials. They also typically have greater resistance to moisture absorption than organic compounds, resulting in a longer lifetime with better stability.

The electrolyte of dilute sulfuric acid maintains high durability even under high-temperature and high-humidity conditions. A proprietary separator membrane has been developed from a high heat-resistant material whose pore diameter does not close even after extended use to improve the robustness at high temperatures. Small-cell super capacitors from KEMET feature a high-strength vulcanized rubber bond to ensure against liquid electrolyte leakage. The cross-section shown in figure 2 explains how these supercapacitors are constructed, including the aqueous electrolyte, rubberized electrodes, and separator membrane.