The nanowires developed at MIET will help triple the operating time of gadgets
Scientists at the National Research University of Electronic Technology developed the nanomaterial, which will increase the battery capacity several times and will allow heat losses to be converted into electricity, for example, from hot pipes. The created method of production of nanostructures is said to be much cheaper and safer than analogues. The results are published in the Journal of Raman Spectroscopy.
According to the MIET, nanostructures based on germanium (Ge), for example, silicon-germanium nanocomposites, are extremely promising, firstly, when creating high-temperature thermoelectric generators, and secondly, when developing new types of rechargeable batteries.
Thermoelectric generators are one of the areas of alternative energy. Such devices allow you to turn excess heat, for example, from pipes and boilers in enterprises and power plants into electricity. Today, this is hindered by the low efficiency and high price of the used materials. Scientists hope that the new method will reduce the cost and increase the efficiency of thermoelectric converters.
Threadlike nanostructures of germanium, according to scientists, have been known for a relatively long time, but the most common method for their fabrication today - gas deposition - has several disadvantages. The main ones are the high cost and toxicity of precursor gases.
Developing a cheap and environmentally friendly alternative to this method, MIET specialists have seriously improved the method of cathodic deposition of germanium from aqueous solutions, proposed several years ago. This approach allows the formation of threadlike nanostructures at room temperature using safe reagents.
Examining the obtained samples, scientists found that the probe laser radiation used in the standard method of optical analysis heats the irradiated portion of the nanostructure enough to melt it. Thus, with the use of a low-power laboratory laser, it was possible to change the structure of the nanomaterial, giving it the necessary properties.
“We showed the possibility of not only crystallization, but even melting of a layer of germanium nanowires formed by the method of deposition from aqueous solutions. Due to the high coefficient of light absorption and low thermal conductivity, the energy absorbed by the structure remains almost entirely in it,” said Alexei Dronov, associate professor at the Institute of Advanced Materials and Technologies of MIET.
Germanium nanowires, according to the scientists, will also serve to improve lithium-ion batteries used in almost every gadget. MIET experts believe that replacing the currently used graphite electrodes with filamentous germanium will increase the battery capacity by 3-4 times with the same dimensions. Scientists noted that over time this technology would replace expensive and flammable lithium with safer and cheaper sodium, maintaining energy intensity at the same level.
In the future, specialists plan to start developing composite thermoelectric materials based on threadlike nanostructures of germanium. The coating from such a semiconductor film will provide, for example, autonomous operation of control equipment in pipelines, will be in demand in utilities, geology, meteorology, and will generally increase the energy efficiency of a large number of processes.