While a few weeks ago we learned that a group of scientists had managed to develop a diamond battery with a duration of around 28,000 years taking advantage of nuclear waste, this time we found a stable sodium battery that, in addition, would be characterized by being very efficient and because it does not have an anode, the area where there is commonly oxidation (that is, electrons are lost).
In this way, it would be a battery not only less expensive, but also significantly smaller, compared to the common size of a traditional lithium-ion battery.
As experts say, when it comes to batteries, lithium-ion batteries tend to be the best around when it comes to energy density. However, the Peng Bay laboratory of the University of Washington has developed a stable sodium ion battery that, in addition to being highly efficient, is much smaller in size and would also cost less to manufacture.
A traditional lithium ion battery consists of an anode and a cathode, where the lithium ions are stored; a spacer to keep the electrodes separated on both sides; and finally an electrolyte, the liquid through which ions move. As the lithium flows from the anode to the cathode, the free electrons exit through the current collector to the device, while the lithium passes from the separator to the cathode.
When charging, the process is reversed and the lithium passes from the cathode, through the separator, to the anode. But the goal of the scientists is to replace lithium with sodium and eliminate the anode , an idea that, originally, is not new. Although, until now, no one had really been able to demonstrate that these types of batteries could have a reasonable useful life, since they can fail very quickly or have a very low capacity.
In addition, batteries without anode tend to be unstable growing dendrites , which are finger-shaped growths that can cause the battery to degrade or shorten rapidly, mainly due to the reactivity of the different alkali metals involved (in this case, sodium).
In this new battery, however, only a thin layer of copper foil has been used, which has been placed on the anode side, functioning as a current collector, so it does not contain active anode material.
And how it works? Instead of flowing to an anode, in batteries without an anode the ions are transformed into metal. Thus, first, they are placed on a copper foil and, later, they dissolve when it is time to return to the cathode.
Scientists confirm that, in their discovery, no dendrites or finger-shaped structures have been found. What’s more, the deposit is very smooth , with a metallic luster, something that would never have been observed for this type of alkali metal.
It would be, it is true, a very interesting advance, since the researchers have been able to build a functional battery with a performance similar to that of a standard lithium-ion battery, with a much smaller size (due to the absence of an anode) , and with the same energy density.
In addition, they also stand out for using a more common metal than lithium batteries, so they would be much cheaper.
