Laptop batteries use chemical energy to generate an electric current, and the limitation is the amount of chemicals you can put inside a certain sized battery. Therefore you need chemical reactions which generate a lot of free charges (ions), and also the ability to reverse the process so the battery can be re-charged by plugging it into the wall.
Well I think one thing you can do is keep the battery really cool. So maybe instead of working on the specific chemical reaction we could develop better cooling systems. I know my macbook generates far too much heat. I think that maybe due t effects on discharge speeds though, the amount of current produced so maybe the battery would no longer be powerful enough.
I’m just speculating to be honest I don’t really know so much about batteries, time to do a bit more reading.
Not sure. You’d need a way to store a lot of energy in a small volume, so high-density, high-charge chemicals would seem to make sense. One way would be use something like a fuel cell: http://en.wikipedia.org/wiki/Fuel_cell