Russian and Finnish scientists jointly developed flexible supercapacitors

A scientific researcher at the Skolkovo Institute of Technology in Russia and the Aalto University in Finland jointly developed a flexible supercapacitor. The electrode uses single-walled carbon nanotubes, and the insulating layer is made of boron nitride nanotubes. Capacitors can tolerate deformation and have the characteristics of simple manufacture and long service life. Relevant results were published in the Scientific Reports scientific journal.

Russia-Finland joint research team returned to the "classical" technical route, that is, the use of "double electrode + insulation layer" of the capacitor structure program. The electrodes of the flexible supercapacitor are single-walled carbon nanotubes. The porous structure of the material can ensure the developed specific surface area of the electrode, thereby increasing its electric capacity, and the material is chemically stable and is a good conductor. The space between the electrodes is filled with boron nitride nanotubes as the insulating layer, and the material has good insulation properties. The thickness of 0.5 mm can ensure the corresponding insulation index requirements, and the material has high strength and good plasticity.

The test result of the flexible supercapacitor test shows that after 20,000 charges and discharges, the capacitor can still maintain 96% of the initial capacity, its equivalent internal resistance is low, only 4.6 ohms, and it can withstand more than 1 thousand tensile tests. The amount of elongation can reach 50%. The super capacitor is prepared by dry deposition and vapor deposition. The process is simple and the cost is low. It is expected that the flexible super capacitor will soon enter mass production.

An ordinary capacitor is composed of two electrodes and an insulating layer, and the structure of the super capacitor is relatively complicated. The space between the electrodes is filled with the electrolyte, and the ion layer formed at the junction of the nominal electrode and the electrolyte functions as an electrode. The rapid development of electronic technology has continuously raised new performance requirements for capacitors, and the miniaturization of electronic equipment requires the miniaturization of capacitors as its important components. This requires constant improvement and development of new capacitors.

In recent years, people are keen on flexible notebook computers, which in turn imposes performance requirements on capacitors that can withstand bending and stretching. In this case, the supercapacitors based on polymers and electrolytes cannot meet the requirements. First, the physical properties do not meet the requirements and the mechanical strength is low. Second, the specifications are large, and the material thickness is generally 0.2 mm. The method of reducing the size of the capacitor causes a sharp increase in the internal resistance of the capacitor. In terms of performance indicators, flexible supercapacitors have a broader market space.