NREL recently patented the Internal Short Circuit device to enhance lithium-ion battery designs by testing effects of latent internal short circuit and related escalating temperatures, which can lead to thermal runaway. Built into battery being tested, NREL tool is capable of replicating naturally occurring internal short without tampering with cell exterior. Device can produce all 4 types of shorts: electrode to electrode, electrode to cathode, electrode to anode, and cathode to anode.