The research status of different energy storage dielectrics is summarized, the methods to improve the energy storage density of dielectric materials are analyzed and the development trend is prospected. It is expected to provide a certain reference for the research and development of energy storage capacitors.
The strategy effectively suppresses electron multiplication effects, enhancing the thermal conductivity and mechanical modulus of dielectric polymers, and thus improving electric energy storage capacity. Briefly, the key problem of polymer dielectric energy storage materials is to enhance their dielectric permittivity.
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.
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.
In order to improve the dielectric energy storage performance, two dimensional (2D) inorganic nanosheets (NSs) such as conductive graphene, semi-conductive Bi 2 Te 3 and insulating BN nanosheets have been incorporated into polymer matrix.
In addition, there is a positive correlation between the polarization and the relative permittivity (εr), the dielectric materials withstand the upper limit of the exerted electric field, which is called breakdown strength (Eb). Accordingly, the dielectric energy storage materials that possess concurrent high εr and Eb are desired for high Ue.