Handbook of Energy Storage for Transmission or ... - W2agz.com

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Power, Specific – Power per unit mass usually expressed as kilowatts/kilogram.
Power density - Power per unit volume usually expressed as kilowatts/liter.
Pulse Ragone plot – The relationship showing the energy delivered by a capacitor during
a given discharge time. This plot shows the effective energy density of the capacitor for
different discharge periods.
Ragone plot – The power and energy relationship commonly used to compare different
energy storage devices. The plot is usually shown as a log – log scale with specific
power for the independent variable and specific energy for the dependent variable.
Symmetric capacitor – See type I capacitor and type II capacitor
type I electrochemical capacitor - The first type of electrochemical capacitors developed.
These are of symmetric design and utilizing two activated carbon electrodes with sulfuric
acid or potassium hydroxide electrolyte.
type II electrochemical capacitor – The type of electrochemical capacitor with symmetric
design utilizing activated carbon electrodes and an organic electrolyte. Organic
electrolytes allow operation at higher voltage. Type II electrochemical capacitors are
probably the most common type in use today.
type III electrochemical capacitor - The type electrochemical capacitor that is of
asymmetric design, using one activated carbon electrode and one high capacity batterylike
electrode with an aqueous electrolyte.
type IV electrochemical capacitor - The type electrochemical capacitor that is of
asymmetric design, using one activated carbon electrode and one high capacity batterylike
electrode with an organic electrolyte. There are no commercial type IV products;
this technology is the subject of present research. (Telcordia Technologies, Inc. is
sampling an asymmetric type IV capacitor that has a carbon cathode and a Li-titanate
anode that uses an organic electrolyte.
Electrochemical Capacitors 55