A major driving factor in the advancement of lithium-ion batteries for automotive use was the patent issues surrounding large-format NiMH batteries.* Once Chevr

A major driving factor in the advancement of lithium-ion batteries for automotive use was the patent issues surrounding large-format NiMH batteries.* Once Chevron got its grubby hands on the NiMH patents, the technology was effectively dead in the water. * https://en.wikipedia.org/wiki/Patent_encumbrance_of_large_automotive_NiMH_batteries https://en.wikipedia.org/wiki/Patent_encumbrance_of_large_au... Interesting that Patent #6969567 expires a week from today. I doubt that will lead to a revival of NiMH technology, though.