I think that there wasn't as much demand for batteries in the past as there has been this decade. Think of all the things that need batteries now that didn't e

I think that there wasn't as much demand for batteries in the past as there has been this decade. Think of all the things that need batteries now that didn't exist in quite as large numbers 10 years ago. Laptops, phones, tablets, household devices, cars, power utility energy balancing, UPSes, personal sensors. Usage of these things in a battery-powered context has grown by several orders of magnitude, a really truly huge amount, and that level of demand is driving battery research forward. There also seems to be a shift from disposable to rechargeable. It's also the other way around, too, of course. I would have thought it ludicrous in the 90s to have my primary vacuum cleaner be battery powered. But this year, I didn't even think twice about it.