Energy storage testing The energy storage performance of polymer dielectric capacitor mainly refers to the electric energy that can be charged/discharged under applied or removed electric field. There are currently two mainstream methods for testing capacitor performance.
Due to the vast demand, the development of advanced dielectrics with high energy storage capability has received extensive attention , , , . Tantalum and aluminum-based electrolytic capacitors, ceramic capacitors, and film capacitors have a significant market share.
The energy storage dielectrics include ceramics, thin films, polymers, organic–inorganic composites, etc. Ceramic capacitors have the advantages of high dielectric constant, wide operating temperature, good mechanical stability, etc., such as barium titanate BaTiO 3 (BT) , strontium titanate SrTiO 3 (ST) , etc.
However, the low dielectric constant of polymer films limits the maximal discharge energy density, and the energy storage property may deteriorate under extreme conditions of high temperature and high electric field , , .
Currently, dielectric energy-storage materials are limited in their applications due to their low energy density. Therefore, dielectric materials with excellent energy storage performance are needed.
The accumulated energy in the capacitor during several charging cycles can be quickly released to generate a strong pulse power. Besides U, Urec, and η, the temperature stability, fatigue endurance, and discharge time are also important parameters for evaluating the energy storage performance of the dielectrics.