Sustainable Energy Storage Systems: Polypyrrole Filled Polyimide-Modified Carbon Nanotube Sheets with Remarkable Energy Density

Organic materials are emerging as promising candidate for electrode material for lithium-ion batteries and supercapacitors because of their unique properties and potential advantages over traditional inorganic materials. This paper is focused on polypyrrole doped surface modified carbon nanotuube sheets as electrode materials for energy storage devices such as lithium-ion batteries and supercapacitors. The advantages, challenges, and ongoing developments in this area are discussed and electrode materials properties such as energy density, cycling stability, and specific capacitance are systematically investigated. This paper also addresses the limitations of organic electrode materials such as low energy density, cycling stability, poor discharge capability. It presents a systematic study and investigation of polypyrrole doped polyimide-modified carbon nanotube sheets. The effect of polyimide processing temperature and polypyrrole deposition time on the electrochemical properties of the electrode materials were investigated. Electrochemical impedance spectroscopy, EIS showed that short deposition times of about 60s and low processing temperatures between 80 and 150˚C provided the best balance between electrode material structure, and electrochemical properties. This study provides a methodology for constructing electrode materials with a combination of high energy and power densities. This study also shows that the processing conditions that produced electrode materials that exhibited a combination of redox reactions and charge displacement mechanisms, typical of a pseudosupercapacitor, resulted in the highest specific capacitance and energy density.