A lot of folks are being dismissive of batteries with a longer life, because devices that use batteries also become obsolete; conveniently, it happens on about

A lot of folks are being dismissive of batteries with a longer life, because devices that use batteries also become obsolete; conveniently, it happens on about the same schedule for some people. But, that misses the point. A battery that lasts dramatically longer means you can deploy batteries in ways and places that couldn't be deployed before, and you can use them in ways we don't currently think "I know, I'll use a battery!" Power for the grid is one of those areas. We don't store generated power right now, because it is too expensive. Partly it is too expensive because batteries are inefficient and horribly short lived. A battery that lasts 25 years could be matched with solar panels that last 25 years (or more) to provide a very effective replacement for grid power. This is just my own take on what a much longer lived battery might be used for. I'm certain there are tons of implementations that aren't obvious to me. Even if a battery with a 20 year life cycle never makes it into a phone, it would still be revolutionary.