Scientists developed new lithium-ion battery, with greater resistance to extreme cold
Reaching temperatures below their freezing point, lithium-ion battery anodes become sluggish, holding less of a charge and consuming power quickly. This affects a large number of devices, since devices such as our mobile phones, computers and, on a larger level, electric cars, use this medium as a source of energy.
A team of researchers designed an alternative to the traditional model of these batteries, adapting them to better resist extreme cold.
Lithium-ion batteries that resist very low temperatures
Lithium-ion batteries have a good reputation today, recognized as the preferred choice for powering rechargeable electronic devices, thanks to their ability to store a lot of energy and their long lifespan.
Despite those benefits, extremely low temperatures are an obstacle to the proper functioning of these batteries. Under these conditions, mobile phones and other electronic devices need to be recharged more frequently, as well as electric cars have a lower autonomy range, reducing their ability to travel longer distances. Even at a certain point of extreme cooling, these batteries completely lose their ability to transmit power.
To improve the electrical performance of the aforementioned batteries, a team of researchers presented their alternative through ACS Central Science. Specifically, they have replaced the graphite anode present in a lithium-ion battery, with an irregular carbon-based material, which preserves its rechargeable storage capacity down to -35 ° C.
In their research, the scientists determined that the planar orientation of the graphite at the anode is responsible for the decreased energy storage capacity of a lithium-ion battery if it is subjected to cold. So, the team opted to modify this traditional material in the manufacture of these batteries for one based on carbon, to improve the process of transferring charge from the anode.
To create this new material, the researchers heated a cobalt-containing zeolite imidazolate framework (known as ZIF-67) to high temperatures, resulting in a material with excellent electrical charge transfer capabilities.
To test this ability, the team used preheated ZIF-67 as the anode, with lithium metal as the cathode, inside a button-shaped battery. The anode demonstrated stable charge and discharge at temperatures from 25°C to -20°C, retaining 85.9% of its energy storage capacity at room temperature, just below freezing.
By comparison, lithium-ion batteries made with other carbon-based anodes, including graphite and carbon nanotubes, had almost no charge at subzero temperatures. When the researchers lowered the air temperature to -35°C, the anode made from the new material still turned out to be rechargeable and, during its discharge, released almost 100% of the charge put into the battery.
The researchers point out that the implementation of this new material could open up the possibilities of using these energy sources at extremely low temperatures, addressing a problem that has already been patented in the use of electric cars during the winter, a period of the year that can wreak havoc. on these vehicles, particularly within certain regions where winter can be more aggressive.
