Right now the problem with most of the batteries in our electronic devices like laptops, smartwatches, smartphones, tablets, and so on is that they have a finite lifespan. We’re not talking about how long each battery lasts per charge, but how long a battery lasts in general while still being able to hold most of its charge.
You might notice that as time passes on, 100% does not get you the same amount time as it did when you first bought your device. However it seems that this is something Samsung and MIT are working to fix. It seems that together with Samsung, MIT has discovered a way of creating batteries that could potentially last forever.
This is done by replacing the existing liquid substance found inside most batteries with a solid material instead. Apparently this will allow a battery to hold its charge for pretty much forever. The new batteries are also expected to be more resistant to temperature and external factors, meaning that the days of worrying about your phone exploding next to your face should be gone (hopefully).
Unfortunately there is no telling when these batteries will make it into consumer devices, but hopefully it will be in the near future. In the meantime there have been plenty of research done on creating safer and longer-lasting batteries, but so far none have made it into the mainstream yet.