My major research activities are focused on synthesis, characterization of materials and study of ion-transport phenomena in new nanostructured electrodes and solid electrolytes for energy-storage devices.
The microelectronics industry is continually reducing the size of its products in order to produce small devices such as medical implants, microsensors, self-powered integrated circuits or microelectromechanical systems. Such devices need rechargeable microbatteries with dimensions on the scale of 1–10mm3, high energy density and high power capability. 3D concentric on-Si-chip architecture developed by our group, enables the fabrication of a network of 10,000-30,000 microbattery units connected in parallel that minimizes the ion-path length between the electrodes and provides high capacity per footprint area. This is achieved by the insertion of four consecutive thin-film-battery layers in the high-aspect-ratio microchannels (40-50µm diameter, 500µm depth) of the perforated chip. We have recently developed an inexpensive and simple electrodeposition method for the preparation of nanosize molybdenum oxysulfide and copper sulfide cathodes. An electrophoretic deposition (EPD) method for the preparation of thin-film LiFePO4 cathodes has been developed for the first time. My current research exploits a new approach for the preparation of ordered solid electrolytes by electrophoretic deposition. I am also interested in the combined effect of EPD and a homogeneous/gradient magnetic field. Within the framework of this research, different solvents and surface-active agents are tested for achieving well dispersed nanoparticles in stable suspensions. Such systems are controlled by the complex interplay of concomitant phenomena, including micellization, association of the surfactant with the polymer and adsorption of the surfactant on the species. Of particular interest is the effect of these cooperative interactions on the structure and ion-transport properties of polymer electrolytes confined in the pores of ceramics. 3D-tomography (to be carried out in collaboration with Imperial College, London) will provide the data sets for the calculation of the tortuosity factor at sub-100nm resolution. To produce core-shell and multiphase ceramic/alkali-metal salt nanoparticles, the method of EPD mechanochemistry is used.
Very recent subjects under investigation include the development and study of redox processes in high-energy-density all-solid-state lithiated Si/S battery and adsorption phenomena in supercapacitors based on porous silicon nanowires.