1 Introduction and Historical Perspective.- 2 Similarities and Differences between Supercapacitors and Batteries for Storing Electrical Energy.- 3 Energetics and Elements of the Kinetics of Electrode Processes.- 4 Elements of Electrostatics Involved in Treatment of Double Layers and Ions at Capacitor Electrode Interphases.- 5 Behavior of Dielectrics in Capacitors and Theories of Dielectric Polarization.- 6 The Double Layer at Capacitor Electrode Interfaces: Its Structure and Capacitance.- 7 Theoretical Treatment and Modeling of the Double Layer at Electrode Interfaces.- 8 Behavior of the Double Layer in Nonaqueous Electrolytes and Nonaqueous Electrolyte Capacitors.- 9 The Double Layer and Surface Functionalities at Carbon.- 10 Electrochemical Capacitors Based on Pseudocapacitance.- 11 The Electrochemical Behavior of Ruthenium Oxide (RuO2) as a Material for Electrochemical Capacitors.- 12 Capacitance Behavior of Films of Conducting, Electrochemically Reactive Polymers.- 13 The Electrolyte Factor in Supercapacitor Design and Performance: Conductivity, Ion Pairing and Solvation.- 14 Electrochemical Behavior at Porous Electrodes; Applications to Capacitors.- 15 Energy Density and Power Density of Electrical Energy Storage Devices.- 16 AC Impedance Behavior of Electrochemical Capacitors and Other Electrochemical Systems.- 17 Treatments of Impedance Behavior of Various Circuits and Modeling of Double-Layer Capacitor Frequency Response.- 18 Self-Discharge of Electrochemical Capacitors in Relation to that at Batteries.- 19 Practical Aspects of Preparation and Evaluation of Electrochemical Capacitors.- 20 Technology Development.- 21 Patent Survey.