Nanotech nerds assemble überfast-charge battery
Two minutes and you're good to go
Three researchers have come up with a technique they claim will allow laptop and smartphone batteries to be recharged in two minutes.
Huigang Zhang, Xindi Yu and Paul Braun of the University of Illinois created a new battery cathode - the negatively charged one - formed "from a self-assembled three-dimensional bicontinuous nanoarchitecture consisting of an electrolytically active material sandwiched between rapid ion and electron transport pathways".
Beyond the boffin-speak, we have a nickel framework electropolished to increase its porosity to 94 per cent. Into the empty space, the scientists poured Nickel Metal Hydride (NiMH) - the battery material, basically - creating a cathode that permits the fast movement ions and electrons, the exchange of which is what makes the battery store charge and then release it when connected in circuit.
When it came to charging the battery, the researchers found they could charge it up to 75 per cent of capacity in just 2.7 seconds. Reaching 90 per cent capacity took 20 seconds.
The only alternative that comes close is a capacitor, but these lack the energy density of a battery.
Want it fully charged? That will take rather longer, the boffins imply, but we think most us can live with 90 per cent capacity given the re-charge speed.
In any case, today's batteries lose capacity over time. So does the trio's battery, but they found it to maintain its capacity for at least 100 charge/discharge cycles.
Improving that will be one part of the technology's development, as will working out how to make the battery commercially viable.
On the basis of their work so far, the team reckon a regular-sized battery can be made which is able to be charged to 90 per cent of its nominal capacity in two minutes. When it might hit the market is another matter entirely.
The boffins also tried lithium-ion as the battery material - the substance used in almost all phone and laptop power packs these days - but found its recharge rate to be rather lower than the NiMH battery: 400 Coulomb to 1,000 Coulomb. ®
How easy would it be to increase the capacity of the batteries to the point where they would be useable in EVs?
The biggest stepping stone with vehicles seems to be the amount of time it takes to charge vs filling a liquid fuel tank. if these batteries charge to 90% in a couple of minutes, take that to EV level and you'd be able to fully charge your car while parked up for an hour doing the shopping...
I think i would still be happy with a Li-ion battery that recharges in only 5 minutes (based on the 2mins at 1000 coloumbs NMH vs 400 columbs for the Li-ion).
I hope they take the time to work on both projects. Still cool idea!
What I don't understand...
What I don't understand, if the charge time is such an issue with EVs, is why car manufacturers don't build cars with removable rechargeable batteries. Get the the petrol(?) station, remove your battery and swap it for a fully charged one, and drive off. Your previous battery gets recharged gradually after your gone and sold to another driver the next day.
I assume manufacturers must have thought about this (it's an obvious idea) so what are the pitfalls? I realise petrol stations would have to factor in the cost of taking batteries out of circulation once they've reached the end of their life and might need some mechanical apparatus to aid removal, lifting and reinsertion of batteries due to their weight but I can't think of any show stoppers.
Anyone know why this hasn't been tried?
Considering how warm my laptop/smartphone batteries get when being charged for 30min, I'm curious just how much heat a 20sec charge will need to dispense of.
Scale that to a 'leccy car
and you have a winner.