They also mentioned "Li-ion batteries cost more to produce, and...

They also mentioned

"Li-ion batteries cost more to produce, and there are some safety concerns surrounding Li-ion batteries (e.g. incidents at Boeing 787 planes)."


You need to read up on the Tesla battery plant $5bill, 6,500 employees, when at full capacity they can produce more battery power from the one plant than the rest of the world currently produces per annum.

And the weight saving is significant, a NiMh battery is 4 to 6 times the weight of a Li for the same KW hrs. No memory effect etc, Full eletric cars do not have much of a range running on NiMh due to not being able to carry enough battery capacity due to weight.

And the mega plant is going to halve the cost of Lithium ion batteries.

You only have to look at cordless power tools, Li has taken over.

And that is one of the of reasons that La market price is so low. And yes there was issue with 787's, resolved for some time, otherwise they would not have flight clearance.