Study On The Configuration Design Of Carbon Nanotube Assembly And Device Performance Based On The Requirement Of Wave Energy Conversion

Carbon nanotubes(CNTs)are seamless,tubular,one-dimensional nanomaterials made of one or more layers of graphene coiled around a specific axis,with a very high aspect ratio and large specific surface area.It also has excellent mechanical,thermal and electrical properties.Carbon materials composed of carbon nanotubes have the characteristics of variable configuration(such as fiber,film,etc.),and at the same time have the intrinsic excellent performance of carbon nanotubes and macroscopic geometric characteristics,showing an unprecedented application prospect in the field of energy harvesting in ocean environments.In recent years,energy harvesting devices based on various mechanisms(triboelectric,piezoelectric,ferroelectric,etc.)have been widely studied.However,due to the limitations of power generation characteristics,none of the above-mentioned energy harvesting devices are suitable for low-frequency energy harvesting applications in ocean environments.Our strategy is to focus on the structure design and precise preparation of different carbon nanotube assemblies,deeply discuss their electrochemical double-layer capacitance changes in electrolytes,and apply them to the harvesting of wave energy in the ocean low-frequency environment.The main research contents are listed as follows:(1)Aligned carbon nanotubes were prepared by physical vapor deposition and water-assisted chemical vapor deposition.By adjusting growth time,gas flow rate,growth temperature and other parameters,the structure parameters of the aligned carbon nanotubes were regulated.The height range was 200-800 ?m,and the density was 20-60 mg/cm3.Aligned carbon nanotubes and commercial single-walled carbon nanotubes were prepared to form different carbon nanotube assemblies through different technologies,and their mechanical strength and structural stability were studied.(2)The capacitance properties of different carbon nanotube assemblies were studied,and their wave energy harvesting properties were investigated.The wave energy harvesting characteristics of combined structures of carbon nanotube assemblies were further explored and compared(all in 0.6 M Na Cl solution).(3)Fermat spinning method was used to combine the aligned carbon nanotube stripe and carbon nanotube sheets to prepare the sheath-core structure carbon nanotube fiber as working electrode.The energy harvesting device based on electrochemical principle was designed and assemblied.Then,the output power and energy,energy conversion efficiency of the device to electrochemically convert the wave energy into electric energy were tested and working mechanism was discussed in detail.