Abstract
Electrodes play an important role in determining the performance of electrochemistry properties, such as specific capacitance of supercapacitors and discharging capability of batteries. Recent studies focus on cathode materials and found that carbon nanotube papers are one of potential cathode materials because of their light weight and low cost. Papers are flexible and may replace metal based cathodes for flexible mobile devices as well as tablet PC in the future. Here acid treated multi-walled carbon nanotubes (MWCNTs) are mixed with normal paper to form conductive papers. By upgrading specific area, we obtain a greater specific capacitance and scan current. For seawater batteries, carbon nanotube papers are used as cathode materials and magnesium alloy (AZ61) as anode. Electrons are released from alloy through oxidations and are then collected by carbon nanotube papers, resulting in H2 generation at cathode. Batteries discharge stably for a small current which is sufficient to power LEDs over 24 h. The physical properties and morphologies of carbon nanotube papers are characterized by field emission scanning electron microscopy (FE-SEM) and Raman measurement. The electrochemical properties, including capacitance, rate capability, discharge test, electrochemistry impedance spectrum analysis, and linear sweep voltammetry, are also studied. Finally, electrochemical properties of carbon nanotube paper are measured by zeta-sizer instrument to uncover the zeta potential, polydispersity index and particle diameter analysis.