Biology-inspired polydopamine-assisted strategy for high-performance supercapacitor

Supercapacitors (SC) have unfolded fascinating potential in new energy vehicles and stationary storage. The investigation of environmentally friendly capacitor strategy is important to accelerate supercapacitors' growth and expansion in commercial presence globally. Herein, a biology-inspired polydopamine (PDA)-assisted strategy is proposed to establish sustainable redox-mediated electrolyte species for high performance supercapacitor. The results prove that the produced PDA conjugated macromolecular electrolyte greatly reduces the large HOMO-LUMO gap and enhances the electronic conductivity. Moreover, the wettability of PDA assisted electrolyte brings a more efficient electrode-electrolyte contact interface by the contact angle reducing from 103.36 degrees to 66.83 degrees. The above properties make PDA aqueous electrolyte highly attractive as supercapacitor electrolytes. Finally, a flexible asymmetric supercapacitor based on polypyrrole (PPy) hollow nanotubes (PNTs) film and carbon nanotubes (CNTs) film is assembled using redox active PDA gel electrolyte. This device shows high specific capacitances and high capacitance retention at high rates in combination with a good stability under cycling (92% of the initial capacitance after 30,000 cycles).