Yuchen Hui

An environmental-friendly supercapacitor based on aqueous electrolyte was fabricated. Electrodes with conductive spider nest–shaped three-dimensional(3D)porous structure was prepared for the assembly of symmetric supercapacitors. The nickel foam was modified by multiwalled carbon nanotubes and β-cyclodextrin. The construction of spider nest was stabilized via the chemical bond inside carbon nanotubes, π-π stack effects among carbon nanotubes, and physical adsorption between nickel foam and carbon nanotubes substrate. The role of β-cyclodextrin is dispersant to prevent agglomeration of carbon nanotubes, thereby enhancing electroactive surface area of nickel foam, and improving the specific capacitance of the electrodes. Furthermore, the electrodes exhibited excellent rate capability. The obtained symmetrical supercapacitors exhibited excellent power density of 17561.3 W kg⁻¹, good specific capacitance of 398.8 F g⁻¹, and energy density of 154.8 Wh kg⁻¹ for 4000 cycles with outstanding cycling stability. In addition, the specific capacitance, energy density, and power density of the supercapacitor operating in seawater were found to be 100.2 F g⁻¹, 17.8 Wh kg⁻¹, and 2568 Wh kg⁻¹, respectively, for 3000 cycles. Overall, our findings indicate that the supercapacitor could stably operate in seawater and shows potential for use as an eco-friendly power supply to marine engineering equipment.

A stable three-dimensional glucose/oxygen enzymatic biofuel cell is fabricated based on the method of polymer encapsulation-based immobilization. And three-dimensional carbon felt is used as the substrate of the bio-electrode for increasing enzymatic loading density. Gold nanoparticles and multi-wall carbon nanotubes are employed to promote direct electron transfer and enhance conductivity and electron conduction rate of bio-electrodes. Glucose dehydrogenase and bilirubin oxidase are immobilized with tetrabutylammonium bromide (TBAB) modified Nafion, which enhances the stability of the bio-electrodes by the immobilization method. A membrane-free glucose/oxygen biofuel cell is assembled with a high open-circuit voltage of 0.85 V and a maximum power density of 21.9 ± 0.1 μW/cm² in 0.1 M pH 7.0 phosphate buffer solution with 100 mM glucose and air saturation. And the biofuel cell shows high stability to the condition. After 60 days of periodic storage experiments, the performance of the enzymatic biofuel cell still maintained 90.3% of its electrochemical performance.