Scientists solve battery mystery – allowing for ultra-fast charging breakthrough

Stanford University team says solution could transform electric car industry

Scientists say they have finally figured out how to overcome a major barrier to ultra-fast battery charging.

The mysterious short circuiting and failure of next-generation lithium metal batteries was solved by a team from Stanford University and SLAC National Accelerator Laboratory in the US, who said their findings could have major implications for the electric car industry.

Rechargeable lithium metal batteries are lightweight, inflammable, hold a lot of energy and can be charged very quickly, however until now they have been unsuitable for commercial use due to mechanical stress experienced while charging.

“Just modest indentation, bending or twisting of the batteries can cause nanoscopic fissures in the materials to open and lithium to intrude into the solid electrolyte causing it to short circuit,” said Associate Professor William Chueh at the Stanford Doerr School of Sustainability.

“Even dust or other impurities introduced in manufacturing can generate enough stress to cause failure.”

The phenomenon has puzzled researchers for years, with some hypothesising that it was due to the unintended flow of electrons, while others claimed it was a chemical issue.

The Stanford scientists undertook a series of 60 experiments to prove that the problems were in fact caused by nanoscopic cracks, dents and fissures within ceramic electrolytes.

“Given the opportunity to burrow into the electrolyte, the lithium will eventually snake its way through, connecting the cathode and anode,” said Geoff McConohy, who used to work in Associate Professor Cheuh’s lab but now works in industry. “When that happens, the battery fails.”

The research was detailed in a study, titled ‘Mechanical regulation of lithium intrusion probability in garnet solid electrolytes, published in the scientific journal Nature Energy on Monday.