34
Electrochemical Supercapacitors for Energy Storage and Delivery
2250 V test is used for testing Class Y capacitors. Both types are used in high
(ceramic) and low (polymer) radio frequency and automotive applications.
1.7.6 Ferrodielectric Capacitors
Ferrodielectric capacitors are shaped as tubes, monoliths, multilayers, or
disks. They normally use ceramic dielectrics because of their high dielectric
constants (1000 < ε r < 30,000). However, the capacitance of a ferrodielectric
ceramic capacitor is strongly dependent on the operating temperature, frequency, and voltage, where the effect of instability on the relative capacitance with respect to dielectric strength is demonstrated using two different
ε r values. These types are called non-linear capacitors and will be discussed
briefly below.
1.7.7 Polar Polymer Dielectric Capacitors
Polar polymer dielectric capacitors are miniaturized devices that are widely
used in miniaturized circuits in modern electronics. In fabricating polar
polymer dielectric capacitors, a physical vapor deposition process is used
to coat polycarbonate foil with an Al layer (≤0.5 μm) to act as the electrode
plates. Melted metal is then deposited by an airbrush method on either a
cylindrical or flattened roll to provide contacts for the terminal connections.
By changing the dielectric thickness, the capacitor’s voltage can be changed
from 60 to 250 V.
1.7.8 Linear and Nonlinear Capacitors
Capacitor types can also be divided into linear and nonlinear capacitors
according to the dielectric material used. In general, if the capacitance does
not change when the operating voltage and frequency are changed, the
capacitor is a linear type. If the capacitance changes when the operating voltage and frequency are changed, the capacitor is a non-linear type. Generally,
linear capacitors are the most widely used; nonlinear capacitors have specific
niche applications.
1.8 Summary
As essential elements in electrical circuits, capacitors have been used in the
operation of countless systems and devices ranging from high power engines
to microcircuits. The two classes of capacitors are: (1) Class I linear capacitors
and (2) Class II nonlinear capacitors. In this chapter, a concise introduction
of the principles and fundamental operations of capacitors from a science
Electrochemical Supercapacitors for Energy Storage and Delivery
2250 V test is used for testing Class Y capacitors. Both types are used in high
(ceramic) and low (polymer) radio frequency and automotive applications.
1.7.6 Ferrodielectric Capacitors
Ferrodielectric capacitors are shaped as tubes, monoliths, multilayers, or
disks. They normally use ceramic dielectrics because of their high dielectric
constants (1000 < ε r < 30,000). However, the capacitance of a ferrodielectric
ceramic capacitor is strongly dependent on the operating temperature, frequency, and voltage, where the effect of instability on the relative capacitance with respect to dielectric strength is demonstrated using two different
ε r values. These types are called non-linear capacitors and will be discussed
briefly below.
1.7.7 Polar Polymer Dielectric Capacitors
Polar polymer dielectric capacitors are miniaturized devices that are widely
used in miniaturized circuits in modern electronics. In fabricating polar
polymer dielectric capacitors, a physical vapor deposition process is used
to coat polycarbonate foil with an Al layer (≤0.5 μm) to act as the electrode
plates. Melted metal is then deposited by an airbrush method on either a
cylindrical or flattened roll to provide contacts for the terminal connections.
By changing the dielectric thickness, the capacitor’s voltage can be changed
from 60 to 250 V.
1.7.8 Linear and Nonlinear Capacitors
Capacitor types can also be divided into linear and nonlinear capacitors
according to the dielectric material used. In general, if the capacitance does
not change when the operating voltage and frequency are changed, the
capacitor is a linear type. If the capacitance changes when the operating voltage and frequency are changed, the capacitor is a non-linear type. Generally,
linear capacitors are the most widely used; nonlinear capacitors have specific
niche applications.
1.8 Summary
As essential elements in electrical circuits, capacitors have been used in the
operation of countless systems and devices ranging from high power engines
to microcircuits. The two classes of capacitors are: (1) Class I linear capacitors
and (2) Class II nonlinear capacitors. In this chapter, a concise introduction
of the principles and fundamental operations of capacitors from a science