Solid state batteries, we are told, are the new hot battery technology that will replace lithium-ion batteries. Soon. Not that we haven’t heard that before. One reason it isn’t dominating the market today is that it’s prone to short circuits during charging. [Dr. Yuwei Zhang and others have published a paper detailing why the shorts happen, which could lead to strategies to improve the technology.Solid state batteries employ a solid electrolyte and a lithium anode. It is known that, sometimes, lithium metal from the anode forms dendrites that penetrate the ceramic electrolyte and cause it to crack. This is somewhat of a mystery as the lithium is a soft metal (to quote [Zhang], “like a gummy bear.”).There were two leading hypotheses for the observations. [Zhang’s] team showed that hydrostatic stress made the lithium dendrites act like a water jet, enabling them to penetrate the hard ceramic.There is still work to figure out what to do about it, but understanding the root cause is certainly a step in the right direction. We’ve looked at these batteries before. We’ve also seen how changing the anode construction might help with the problem.