Engineering news
Researchers at Stanford University have identified solid electrolytes that could replace the volatile liquid batteries used in electronic devices, using techniques adapted from artificial intelligence and machine learning.
Electrolytes shuttle lithium ions back and forth between the battery’s positive and negative electrodes. Liquid electrolytes are cheap and conduct ions well, but can ignite if the battery overheats or is short-circuited by puncturing.
Battery fires led to the recent recall of nearly two million Samsung Galaxy Note7 smartphones, the latest in a series of highly publicised lithium-ion battery failures.
Austin Sendek, a doctoral candidate in applied physics, said: “The main advantage of solid electrolytes is stability. Solids are far less likely to explode or vaporise than organic solvents. They’re also much more rigid and would make the battery structurally stronger.”
Researchers have yet to find an inexpensive solid material that performs as well as liquid electrolytes at room temperature.
The team used artificial intelligence and machine learning to build predictive models from experimental data instead of trial and error. They trained a computer algorithm to learn how to identify good and bad compounds based on existing data, much like a facial-recognition algorithm learns to identify faces after seeing several examples.
Sendek added: “We developed a computational model that learns from the limited data we already have, and then allows us to screen potential candidates from a massive database of materials about a million times faster than current screening methods. We screened more than 12,000 lithium-containing compounds and ended up with 21 promising solid electrolytes.”
To build the model, Sendek spent more than two years gathering all known scientific data about solid compounds containing lithium.
The model used several criteria to screen promising materials, including stability, cost, abundance and their ability to conduct lithium ions and re-route electrons through the battery’s circuit.
The results are published in the journal
Energy & Environmental Science.