Niobium capacitors are available from a value of 1 to 1500 micro farad. Over time, the niobium capacitors have stable values of capacitance, leakage current and equivalent series resistance (ESR) so the functionality and reliability of the capacitors used in the electrical circuits remains consistent over a long period of time. Niobium capacitors are used in power supplies, DC/DC converter applications, air bag controls, car seat position modules and car audio devices.

Niobium capacitors are polarised capacitors, which means that there is a positive or anode terminal and a negative or cathode terminal for connection in a circuit. Niobium capacitors consist of a layer of Niobium pentoxide which is formed around Niobium monoxide grains used as dielectric.

Niobium capacitors are available in the form of a surface-mount device (SMD) chip capacitors. As they are polarised, they can be used only with DC voltage sources. The reverse DC voltage connections may damage the dielectric and hence the capacitor. There are specific rules of circuit design that need to be followed to prevent such damage.

Niobium capacitors can be made either by doping metallic niobium powder with nitride into passivated niobium nitride or using niobium oxide as anode material. Niobium oxide is a hard ceramic material characterized by high metallic conductivity. Niobium oxide powder can be prepared and processed to produce capacitors.