Preparation and characterization of polyaniline/metal oxide electrodes for supercapacitor applications

Flexibility is an important parameter in the use of wearable technological products. Energy storage systems must also be flexible in the use of such technologies. The motivation of this thesis is the investigation of easy and inexpensive formation of flexible energy storage materials with high power and energy density. In this thesis, metal oxide and conductive polymer were obtained on known current collectors (nickel, stainless steel) and a newly produced flexible current collector based on adhesive tape. Modified electrodes based on CoOx and polyaniline (PANI) were obtained electrochemically from different liquids. It was investigated how the performance of the electrodes changes with the growth conditions of the electrodes. The effect of growth electrolyte (ionic liquids, organic liquids and aqueous solutions), film thickness and applied voltage was analyzed. The behavior of the resulting electrodes in different electrolytes (basic, acidic and neutral) was investigated. The Co-coated stainless steel electrode showed a maximum capacitance density of 1692 F g-1 at 5 mV s-1. While the capacitance retention of PANI film deposited in Ethaline ionic liquid is 87% after 10 000 cycles, the capacitance of polyaniline produced by electrochemical method from acidic medium reaches 50% after 500 cycles. PANI and graphite-based electrodes studied in this thesis are promising for high-performance flexible supercapacitors.