Which is better, solid state capacitor or electrolytic capacitor

The full name of state capacitor is: solid aluminum electrolytic capacitor. The biggest difference between it and ordinary capacitor (i.e. liquid aluminum electrolytic capacitor) is that it uses different dielectric materials. The dielectric material of liquid aluminum capacitor is electrolyte, while the dielectric material of solid capacitor is conductive polymer material. To help you understand which is better, solid state capacitor or electrolytic capacitor?

Difference between solid state capacitor and electrolytic capacitor

1. The definitions of solid state capacitance and electrolytic capacitance are different:

The biggest difference between solid electrolytic capacitor and ordinary capacitor is that different dielectric materials are used. The dielectric material of liquid aluminum capacitor is electrolyte, while the dielectric material of solid capacitor is conductive polymer material.

Electrolytic capacitor is a kind of capacitor. The metal foil is the positive electrode, and the oxide film (aluminum oxide or tantalum pentoxide) close to the metal is the dielectric. The cathode is composed of conductive materials, electrolyte and other materials. Because the electrolyte is the main part of the cathode, electrolytic capacitor is named.

2. The principles of solid state capacitor and electrolytic capacitor are different:

Solid state capacitor, aluminum electrolytic capacitor adopts solid conductive polymer material instead of electrolyte as cathode, and has made innovative development. The conductivity of conductive polymer materials is usually 2 to 3 orders of magnitude higher than that of electrolyte. It can greatly reduce ESR and improve temperature frequency characteristics when applied to aluminum electrolytic capacitors.

Electrolytic capacitor is usually made of metal foil (aluminum/tantalum) as the positive electrode, and the insulating oxide layer of metal foil (aluminum oxide/tantalum pentaoxide) as the dielectric. Electrolytic capacitor is divided into aluminum electrolytic capacitor and tantalum electrolytic capacitor according to its positive electrode;

The negative electrode of aluminum electrolytic capacitor is composed of thin paper/film or electrolyte polymer soaked with electrolyte solution; The negative electrode of tantalum electrolytic capacitor is usually manganese dioxide. Electrolytic capacitor is named because it uses electrolyte as negative electrode.

3. The role of solid state capacitor and electrolytic capacitor is different:

The solid capacitor uses polymer dielectric. At high temperature, the solid particles are lower than the liquid electrolyte in terms of particle swelling or activity, and its boiling point is as high as 350 ℃, so it is almost impossible to appear the possibility of slurry explosion. Theoretically, it is almost impossible for solid state capacitors to burst.

Electrolytic capacitor usually plays the role of power filter, decoupling, signal coupling, time constant setting, DC isolation, etc. in power supply circuit or medium frequency and low frequency circuit. Generally, it cannot be used in the AC power supply circuit. When it is used as a filter capacitor in the DC power supply circuit, its anode (positive) should be connected with the positive end of the power supply voltage, and the cathode (negative) should be connected with the negative end of the power supply voltage. It cannot be reversed, otherwise the capacitor will be damaged.

After understanding the difference between the two, which is better, solid state capacitor or electrolytic capacitor?

In terms of electrical performance, solid capacitors and ordinary electrolytic capacitors have their own advantages. The biggest advantage of the former is that no liquid electrolyte is used, so it is not easy to "bulge", "burst" and other situations when heated, with long service life and good thermal stability, and is suitable for high-frequency working environment; The latter is cheap, large in capacity and high in withstand voltage. There is a very simple way to distinguish solid state capacitor from electrolytic capacitor, that is to see whether there is a "K" or "+" shaped slot on the top of the capacitor. Solid state capacitors are not slotted, and electrolytic capacitors have slots on the top to prevent explosion due to expansion after heating. Compared with the common liquid aluminum capacitor currently used, the physical difference of the solid aluminum electrolytic capacitor is that the conductive polymer dielectric material used is solid rather than liquid. In the case of long-term power failure, the material will not react with aluminum oxide. After power on, it will not easily cause slurry explosion or even explosion phenomenon like the ordinary liquid aluminum capacitor.