Yeah, those bags are probably the best option. Phone and laptop batteries are only getting bigger, and you're not going to be able to ban them on planes. Non-flammable batteries would be great but if only that one startup is working on them, there must be some reason they aren't being used yet.
The article feels a little thrown-together, though. It's hyping the panic of passenger flights where a carryone battery catches fire, but the stats and quotes seem to be talking about cargo shipments.
It says "CBS News reviewed the last five years of data in NASA's Aviation Safety Reporting System, which includes 879 anonymous reports of in-flight hazmat incidents on passenger planes. The data shows that neither pilots nor the airlines were told the hazardous materials were even on board their planes in 62% of those cases, even though notification is required by law. " But the
https://www.faa.gov/hazmat/packsafe/lithium-batteries page mentioned at the end of the article doesn't say anything about mandatory notification.
Just after that, a pilot is quoted saying "I'm concerned. [If I were the pilot on one of those flights] I'd be enraged. How dare you not follow the procedures and let me know what's on the airplane?" . That quote has to have been taken from a conversation talking about cargo flights. He can't possibly think that on a 200-person passenger flight, nobody brought a phone.