Overview of electrochemical double layer capacitors

TLDR: The commercial success of carbon-based ELCCs is due to their low cost, extremely high cycle life, and wide range of operating temperatures as discussed by the authors, where the properties mentioned above give ELCC advantages over rechargeable batteries.

Abstract: Electrochemical liquid double layer capacitors (ELCC) are energy storage devices with properties intermediate between batteries and electrolytic capacitors. The commercial success of carbon based ELCC is due to their low cost, extremely high cycle life, and wide range of operating temperatures. They are used mainly for power backup for electronic circuits where the properties mentioned above give ELCC advantages over rechargeable batteries. ELCC are a promising candidate for load leveling applications in electric vehicles and also pulse power applications. Nonaqueous electrolytes, such as organics, solid polymers, and inorganics offer higher energy densities due to the greater decomposition voltages. Advanced ELCC will likely use metal oxides or conductive polymers to provide higher energy and power densities than carbon based ELCC.