Researchers from the Russian State Technical University and the Institute of Physics, Chemistry and Electrochemistry of the Russian Academy of Sciences use germanium nanocrystal anodes to make lithium-ion batteries have unprecedented “cold resistance”, thereby avoiding the large loss of charge of lithium-ion batteries under low temperature conditions . Related research results were published in the “Journal of Electroanalytical Chemistry”.
Lithium-ion batteries are popular among battery products because they combine the advantages of high energy density, light weight, and low self-discharge. However, even this type of modern battery loses most of its capacity and power in severe cold. At minus 20 degrees Celsius, the capacity of lithium-ion batteries is only about 10% of that at minus 20 degrees Celsius.
In some cold regions, such as the Arctic, the temperature there can drop to minus 50 degrees Celsius or lower. Therefore, the development of new cold-resistant batteries is an important technical issue.
To solve this problem, researchers synthesized a kind of filamentous germanium nanocrystals and studied their functional properties as anode (ie, battery negative electrode) materials. Researcher Ilya Gavrilin said that for the anode, the conversion capacity (the charge that the electrode can release during normal operation) is about 250 milliamperes per gram at minus 50 degrees Celsius. At this temperature, the most common graphite anode can’t work at all, and the capacity of the special lithium titanate “cold-resistant” anode is reduced to 1/3 to 1/2.
Ilya Gavrilin said that at minus 20 degrees Celsius, the capacity of germanium anodes is 10 times that of standard graphite anodes, while other “cold-resistant” materials have some disadvantages: low working voltage, low capacity, even at room temperature The charging process is also very slow and complicated to manufacture.
Alexei Dronov, an associate professor at the Technical University of Russia, said that filamentous germanium nanocrystals can be obtained from an aqueous solution of germanium oxide on a conductive substrate by electrochemical methods. Because the synthesis technology of the nanostructure is simple, the performance is unique, and many difficulties can be avoided, the cost of the finished product is expected to be relatively low.