The electrolytic capacitor has a high capacitance in relation to its size. There are two basic types, one uses a liquid electrolyte the other a dry.

The liquid electrolyte capacitor's electrodes are mostly made from aluminium and dipped in an acidbath to make its surface porous. This increases the surface area of the electrode over 300 times. The electrodes are then oxidized. This oxide layer forms the dielectrum A layer of paper is put between the two electrodes. This paper is moistened with an electrolyte made from a mix of boric acid, glycol, salt and a solvent. The electrolyte has a low resistance and flows in to all the small holes and crevices in the aluminium oxide. This creates a good contact to the surface, and due to the large surface area, the capacitor gets a high capacitance. These capacitors are polarized and should not be connected the other way as they will explode (this is of course something students of electronic engineering do for fun). These types of capacitors have a capacitance of between 0.1uF to 0.5F and are produced for voltages up to 500V. The length this type of capacitor's 'life' is highly dependant on temperature, its lifelength is halved for each 10 degrees Celsius the temperature increases

The solid electrolyte capacitor (SAL, Solid Aluminium Electrolyte) uses either manganese dioxide or an organic semiconductor as the dielectric material.
They are made in a similar way to the liquid electrolyte capacitor. But uses a fiberglass separator in stead of paper. This is impregnated with the manganese dioxide or the semiconductor, and put between the electrodes. The manganese dioxide is available with values from 0.1uF to about 3000uF, and has a higher tolerance to temperature variation. But their lifetime is more sensitive to the voltage than that of an liquid electrolyte capacitor
The organic semiconductor type are manufactured with values up to about 300uF. They have a higher internal resistance than the liquid electrolyte, but have a better temperature tolerance.
The tantalum capacitor is similar to a SAL but has tantalum electrodes.

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