Aluminum Electrolytic Capacitors
Aluminum electrolytics offer some of the smallest sizes for a given capacitance and voltage. Commonly
used for filtering and bulk energy storage, electrolytics are available in rated voltages exceeding 500 VDC.
KEMET Electrolytic capacitors are utilized in a wide variety of demanding power electronics applications
such as automotive, power generators and converters, welders, wind turbines, uninterruptible power
supplies, and medical imaging.
Electrolytic capacitors consist of aluminum foil which is first etched to increase its surface area. Separate,
carefully designed etching techniques are used for the anode and cathode foils. A layer of aluminum
oxide, an excellent dielectric, is formed on the surface of the etched anode foil before the foils are wound
together between special separator papers. At the same time, tabs are welded to the foils to form the
connections. The wound assembly is impregnated with a liquid electrolyte. This electrolyte is a precision-
made compound which fully impregnates the etched foil, providing a low ESR conductive path to the
cathode foil with stable electrical and chemical properties. KEMET crafts its own electrolytes to match
the etched foil characteristics and desired final properties. The assembly is packaged in such a way as
to provide excellent vibration resistance and low thermal resistance.
KEMET offers a broad line of axial, snap-in, screw terminal and miniature electrolytic capacitors;
however, it is often beneficial to optimize the capacitor to a specific requirement, particularly in
automotive and power applications. KEMET’s systems and production methods are designed with
optimization in mind. By utilizing a “library” of foils, electrolytes, separator papers, and mechanical parts
in carefully selected combinations, KEMET can swiftly design and build optimized electrolytic capacitors
to match a given specification.
dielectric
cathode
Extended cathode
Anode foil
aluminum foil
Foil tabs
aluminum foil
Tissues
anode
paper soaked in electrolyte
electrolyte solution
Cathode foil
Aluminum electrolytic capacitor typical construction
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KEMET [ KEMET CORPORATION ]
