Technical Note
How to use Electric Double Layer Capacitors
INDEX
1. Overview of Electric Double Layer Capacitors
1-1 Basic Mechanism
1-2 Structure
1-3 Characteristics of Constituent Material
1-4 Equivalent Circuit models
2. Basic Performance
2-1 Capacitance
2-2 Resistance
2-3 Leakage Current
2-4 Voltage Decay Performance
2-5 Discharging Performance
2-6 Frequency Response Performance
2-7 Temperature Dependence Performance
3. Life Performance
3-1 Life Performance by Ambient Temperature
3-2 Life Performance by Applied Voltage
3-3 Self-heating by Charging and Discharging
3-4 Life Estimation
[Supplement]
1. Measuring Method of Electrical Characteristics
1-1 Calculating Formula of Capacitance and
Internal Resistance
1-2 Power Density
1-3 Energy Density
2. Modules
2-1 Module Design
2-2 Precautions in Assembling Modules
2-3 Module Calculation Examples
［Precaution Statement］
※The specifications do not guarantee performance.
Nippon Chemi-Con Corporation
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How to Use Electric Double Layer Capacitors
1. Overview of Electric Double Layer Capacitors
1-1 Basic Mechanism
Conventional capacitors have a dielectric sandwiched
between two electrodes. When a voltage is applied, dipoles
are oriented, and thus electric charge is stored. Electric
double layer capacitors have electric charges oriented at
the boundary of electrolyte and electrodes in what is called
the “electric double layer” (see Fig-1).
(Conventional capacitors)
Electric Double Layer
(Electric Double Layer Capacitors)
Fig-1 Mechanism
1-2 Structure
Electric double layer capacitors are constructed of ① the
electrode assembly (separator between electrode, which
consist of aluminum foil and activated carbon, in a rolled
configuration then impregnated with electrolyte), ②
aluminum tabs (connected to each electrode), ③sealing
plate and aluminum case (to contain them) (see Fig-2).
Nippon Chemi-Con produces cylindrical capacitors. The
rolled structure of the cylindrical type is the same as that of
our aluminum electrolytic capacitors. This structure has
high mass productivity because construction material or
production technology of aluminum capacitors can be
applied.
Basic Element Structure (cylindrical)
Fig-2 Structure
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電極
電解液
電極
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Separator
(Electric Paper)
Electrode
Sealing Plate
Aluminum Tabs
Baseplate
Sleeve
Aluminum Case
Dimple
Tape
Element
Sealing Rubber
Screw Terminal
Sealing Plate
Collecting Terminals (tab)
Safety Valve
Electrode
Electrode
Electrolyte