Tantalum capacitors for large energy storage

What is a tantalum capacitor?

Tantalum capacitors are, with ceramic, aluminum and film capacitors, one of the most used family. The manufacturing technology and the constant improvements in tantalum powders allow it to be the capacitor with the highest CV (product capacitance x voltage) per volume, very long life and high reliability.

Are tantalum (MnO2) capacitors a good choice?

It is up to the designer to address how well the dielectric will perform in-application due to electrical, mechanical, and thermal stress; data that may or may not be explicit on manufacturer datasheets. Tantalum (MnO2) capacitors are a good selection for long life applications, because of virtually no wear-out mechanism.

Why are wet tantalum capacitors better?

Higher material and manufacturing cost. Compared to solid tantalum technologies e.g. (MnO2 or polymer electrolyte), wet tantalum capacitors exhibit a higher surge current capability with a higher breakdown voltage (BDV) close to their dielectric formation voltage. This results in capacitors that require less voltage derating.

Which capacitors are suitable for energy storage applications?

Tantalum and Tantalum Polymer capacitors are suitable for energy storage applications because they are very efficient in achieving high CV. For example, for case sizes ranging from EIA 1206 (3.2mm x 1.6mm) to an EIA 2924 (7.3mm x 6.1mm), it is quite easy to achieve capacitance ratings from 100μF to 2.2mF, respectively.