You're out riding your new electric motorcycle and the battery is getting low. No problem, just pull over and fill 'er up. That's the hope of researchers working on an improved redox flow battery.
Electric motorcycles, like electric cars, are just beginning to appear for sale as serious, if somewhat expensive, alternatives to your regular ICE powered vehicle. They're almost like having a regular engine, we're assured, but whenever the subject of range and recharge time comes up we hear a lot of talk about average driving distances for most people, which is another way of saying you can't go very far and recharges take a long time.
OK, so what's this redox flow battery?
The principle of redox flow batteries is not new – two fluid electrolytes containing metal ions flow through porous graphite felt electrodes, separated by a membrane which allows protons to pass through it. During this exchange of charge a current flows over the electrodes, which can be used by a battery powered device.
Sounds great, so what's the problem? Redox flow batteries store about a quarter of the energy of lithium ion batteries, currently the battery of choice for commercially available electric vehicles. At that rate, you would be filling up constantly, but researchers have developed an improved version with a range of 4 to 5 times previous versions, matching lithium ion capacities.
These batteries are recharged by pumping out and refilling the electrolyte. The electrolyte fluid could be pumped out and refilled at the "gas" station in minutes, the discharged electrolyte could then be recharged at the station and reused in other vehicles.
The battery is still in prototype form so it won't be appearing soon, and it is not much better than the current Lithium Ion system, but this is a direction very likely to appeal to everyone used to quick fillups on the road. If the capacity can be improved even more, they could be on to something. Interesting.