Scientists Discover the Holy Grail: the Cause of Lithium-Metal Battery Failure
Lithium metal is the greatest choice when seeking an electrode material for your next-generation battery. Because of their large concentration, low density, and inflammability, lithium-metal batteries may play a role in electric vehicles and the clean tech revolution.
Dendrites, which are microscopic fissures in the ceramic electrolyte, have the potential to induce short circuits in lithium-ion batteries.
The quest to identify why this happens (and to develop a battery that prevents this unwanted effect) is a form of Holy Grail for scientists, and perhaps the science world has found its Galahad.
This week, researchers from Stanford University and the SLAC National Accelerator Center revealed data about the origin of lithium-metal battery dendrites. Previous ideas suggested that the inadvertent migration of electrons or another chemical disaster may cause the battery's failure.
Nevertheless, after completing over 60 experimental experiments, the researchers observed that microscopic "nanoscopic" fissures in the ceramic solid electrolyte occur during rapid charging, with some as fine as 20 nanometers (a human hair is 80,000 nanometers).
These fractures allowed a lithium-metal "bridge" to develop between the anode and cathode, causing a short circuit. The findings were presented in a paper that was published in the publication Nature Energy.
According to coauthor William Chueh, "Little pushing, twisting, or turning off the packets would perhaps cause nanometre rifts in the nanomaterials to establish, enabling lithium to seep the solid electrolyte and causing a short circuit."
"Little pushing, twisting, or having to turn off the packet header might cause nanoscale rifts in the nanomaterials to develop." "Dust and other impurities introduced during manufacture might create enough strain to induce failure."
To understand why lithium penetrated certain places and caused a short circuit, the researchers developed a tiny battery by mixing an electric probe with an electrolyte. When at rest, the lithium anode performed as planned, but any indentation, bending, or twisting (coupled with dust generated during the manufacturing) increased the chance of failure.
The responsible coauthor, Xin Xu, compared the method to potholes. As vehicle tires pound water and snow into minute cracks in the road, resulting in structural failure, the same happens inside battery packs (albeit on a much smaller scale).
Yet, this is not bad news for the destiny of lithium metal; in fact, it is excellent news.
Today, specialists who are already hard at work developing lithium-metal batteries may examine these findings in an effort to eliminate these weaknesses.
The study's authors also add that they are investigating strategies to strengthen the electrolyte during manufacture and to cover the ceramics membranes so that it may self-repair when damaged.
In 2019, the Stanford laboratory devised a method for lithium-metal batteries to retain 85% of their charge after 160 cycles, a significant improvement above the 30% previously observed.
"All of these improvements begin with such a straightforward question: Why?" says coauthor Teng Cui. After we get this information, we may make modifications.
Now that scientists have successfully answered why lithium metal's future is less a question of "if" rather than "when."