Electrochemical Capacitor Technology

Short Course at ECS meetings

Electrochemical capacitors (ECs), often referred to by the product names Supercapacitor or Ultracapacitor, are receiving increased attention for use in power sources of many applications because they provide unexcelled power density, offer extraordinarily high reversibility, and have exceptional cycle-life. Combination systems—for example those with batteries and capacitors, IC engines and capacitors, and fuel cells and capacitors—are now appearing and being used to increase the energy efficiency of vehicles and industrial equipment like fork lifts, trams, and overhead cranes by capturing, then using, energy that is normally wasted.

Topics covered

This tutorial is targeted at technologists interested in understanding, advancing, and/or exploiting electrochemical capacitor technology. First, basics are covered that describe the nature and significance of electric double-layer charge storage, general design of these products, and similarities and differences between electrochemical capacitors and conventional capacitors or common batteries. Two-terminal electrical measurement techniques are discussed and test data is used to develop equivalent circuit models. Power/energy behavior and tradeoffs are presented along with reliability design. Many example applications are covered in detail. The goal of the tutorial is to provide basic understanding, necessary tools, and sufficient operating information to allow direct and successful advancement and/or exploitation of electrochemical capacitor technology.

About the instructor

John MillerJohn R. Miller, President of JME, Inc., has more than 35 years of experience in research, development, and commercialization of electrochemical capacitor technology. Since founding JME in 1989, he has assisted in the development and market introduction of several electrochemical capacitor products now available for industrial, military, and medical applications. Dr. Miller was a pioneer in the development of third-generation asymmetric electrochemical capacitor technology. He has assisted capacitor material suppliers in creating products offering enhanced performance, and assisted the Department of Energy in establishing appropriate test methods and evaluation procedures for large, high-power capacitors. His recent research has focused on graphene-nanosheet-electrode electric double layer capacitors that operate at high-frequency (120 Hz).

Dr. Miller has published more than 100 capacitor-related papers, prepared many government reports, and been awarded 13 U.S. patents. He organized and chaired international conferences on electrochemical capacitor technology and teaches short courses for several professional societies. In addition to his position at JME, Inc., Dr. Miller has been an Adjunct Professor in the Electrical Engineering and Computer Science Department at Case Western Reserve University (part time). His previous positions include research manager at Standard Oil of Ohio (SOHIO), staff scientist at the University of Rochester, and staff member at Los Alamos National Laboratory. He earned his BS and PhD in Physics from the Massachusetts Institute of Technology.