Ferroelectric polymers and nanocomposites for electrical energy storage

Electrical energy storage plays a key role in mobile electronic devices, stationary power systems, and hybrid electric vehicles. There is a great need for development of new materials with superior electrical energy density since current ceramics and polymers fall significantly short of rising demands in advanced applications. The maximum energy density of a dielectric polymer is controlled by the permittivity and electrical breakdown strength of the polymer. Our recent work has demonstrated the ability to precisely control the permittivity of ferroelectric polymers through a unique synthetic approach. The influence of molecular weight and chemical composition on the electrical breakdown strength of these ferroelectric polymers has been investigated in a systematic manner. Polymer nanocomposites were also prepared using surface-functionalized TiO2 nanoparticles and ferroelectric polymer matrices. The nanocomposites exhibit larger electric displacements under the applied fields, thereby leading to higher energy densities.