High-energy storage performance achieved in ZrO2 film-based capacitors
|The pressing demands for the green energy transition are pushing the research agenda to develop advanced solutions for the future of energy storage. Alongside batteries, capacitors can also be used for energy accumulation but, while batteries rely on chemical energy, capacitors work by electrostatic energy. They are also characterised by small volumes, fast charge/discharge, and are not subject to capacity fading over time, although batteries have a much larger storage density.
Dr. José Pedro Basto da Silva (University of Minho, Portugal) with the collaboration of Prof. Koppole Sekhar (Central University of Tamil Nadu, India), Dr. Haribabu Palneedi (Pennsylvania State University, USA), and co-authors, reported for the first time the employment of ferroelectric ZrO2 films as energy storage capacitors. The authors also assessed the effect of different thicknesses of a low permittivity dielectric HfO2:Al2O3 (HAO) layer on the energy storage performances of the ZrO2 film capacitors.
The crystalline nature of the ZrO2 films was investigated by High-Resolution Transmission Electron Microscope (HRTEM) at the Romanian CERIC Partner Facility at the National Institute of Materials Physics with the supervision of Dr. Corneliu Ghica. HRTEM and other experimental procedures demonstrated that energy storage performances could be tuned by controlling the HAO layer’s thickness. Best performances in terms of storage efficiency and energy density were obtained with a 2 nm-thick HAO layer.
This work proved that high energy storage performances could indeed be achieved by simple binary oxides such as ZrO2 films with ferroelectric behaviour as a potential alternative to Pb-based and Pb-free ceramics with complex compositions. The development of different energy technologies is of paramount importance to provide energy for various devices and machinery.