Abstract:

In 1957, Becker’s patent initiated the study of electrochemical capacitors. As a new type of energy storage device, electrochemical capacitors exhibit high power and long life and have attracted considerable research attention. With the progress of research, electrochemical capacitors have transitioned from the original electric double-layer capacitors and pseudo-capacitors to today’s hybrid capacitors and other product types. During industrialization and research, electrochemical capacitors have been distinctly named (e.g., “supercapacitors,” “ultracapacitor,” and “golden capacitors”) based on different purposes. Their classifications also exhibit diversity. Thus, the hybrid capacitors are also called “battery-type capacitors.” The non-professional names and classifications have created unnecessary obstacles for industrialization and product standardization. This study attempts to clarify the naming and classification of electrochemical capacitors for future reference.

Key words: electrochemical capacitor, classification, double layer capacitor, pseudo capacitor, hybrid capacitor