I believe this battery's density is not super impressive that they didn't mention in in the article and the title of the article is about it's safety rather that fast charging time or capacity
Safe and "high-performance" as they claim are somewhat opposing; to a battery that can be discharged at high currents, with a high energy density, there's no difference between dissipating that energy in the usual load it's powering and through a short circuit of equivalent resistance. Even if the battery itself doesn't catch fire or heat up, all that energy still has to go somewhere.