It's not often that there's much in the way of battery related news, yet somehow this week we've had two pop up, and they've gone from one extreme to the other. While yesterday we saw Samsung's awesome 30-day 12 kWh example, today we’re all hot under the collar for a much smaller affair.
Scientists at Rensselaer Polytechnic Institute have developed a method for producing flexible batteries that considering the diminutive proportions, pack a powerful punch. The method (be warned, this gets technical) consists of growing carbon nanotubes on a silicon substrate, layering that with cellulose (that’s paper to you and me) and then removing the silicon layer.
This leaves a layer of paper lined on one side by carbon nanotubes. By putting two layers of this paper together, nanotubes outwards, with an electrolyte in between, a capacitor is formed. Taking this even further, you can cover this paper sheet with a layer of aluminium and lithium foil to create a lithium ion battery.
Unlike a normal Li-On battery however, whose manufacturing process makes the end result relatively heavy and inflexible, these “paper batteries” are flexible and comparatively lightweight. With possible operating temperatures ranging from -75 to 150 Celsius the range of usable environments is up on traditional design as well.
An energy density of 110mAh/g means a 100g device should be able to replace a traditional 1300mAh solid Li-On battery while reducing the size and weight of the devices being powered. Even better, the physical space required by the battery can be reduced from a usual battery by, for example, folding it around components or forming the battery into a roll.
To be honest, the only word that can really be used to describe this development is “cool.”