On the upside. A new way to make Lithium nano wire in various chemistries.
Cryo-EM sounds like a winner that's got lots of directions to go in. It's one of those obvious-when-you-think-about-it-but-no-one-did ideas (then making it work reliably was probably an absolute bu**er to get right).
" By flash-freezing the batteries at different points of its charge and discharge cycle, "
Sadly dunking your overheating cell in a convenient LN2 tanks does not sound like a viable solution.
However. the games not over for Li ion. Obvious strategies are physically stronger separator membranes and some kind of chemically reactive coating to disrupt their formation, or a treatment of the electrode surface to prevent dendrite formation being energetically favourable (which is the usual root cause of this).