New hybrid flow battery can release electricity or hydrogen
The filling station of tomorrow could be able to service electric and hydrogen-fueled cars from not only the same location, but the same pump thanks to a potentially revolutionary breakthrough by chemists at the University of Glasgow. Using nanomolecules suspended in a fluid, the new battery system would not only allow such vehicles to refuel in seconds instead of hours, but can produce either electricity or hydrogen gas on demand.
For decades, engineers have sought an alternative to the internal combustion engine, but have continually stumbled over a number of hurdles. For all their faults, gasoline and diesel are ideal, compact fuels with a very high energy-to-mass ratio. In addition, they are easy to produce and transport, and, at the pump, can refill a vehicle's tank in a couple of minutes.
Hydrogen fuel cell vehicles offer the benefits of gasoline-powered cars when it comes to filling up in a hurry, but they currently lack supporting infrastructure and aren't as commonplace as electric vehicles, which can take hours to recharge. While both are expected to increase in popularity in the medium term, electric and hydrogen vehicles are incompatible when it comes to refueling, but a new type of energy storage system developed at the University of Glasgow could change that.
Led by Leroy (Lee) Cronin, the University of Glasgow's Regius Chair of Chemistry, the Glasgow team's approach is to use a flow battery, which is a type of battery where two tanks of liquid flow past a common membrane held between two electrodes. This membrane allows ions to pass between the two loops of liquid, generating electricity.
The beauty of a flow battery is that is can act like a conventional battery or as a fuel cell. In addition, it can be recharged by removing spent liquids and replacing them with fresh ones. In the case of the Glasgow hybrid-electric-hydrogen battery, the liquid is a suspension of nano-molecules, each of which acts like a little battery. In sufficient concentrations, the team says that the liquid can store very large amounts of energy, which can be released as electricity or hydrogen gas.
According to the researchers, this new battery can be recharged in seconds by simply circulating in new liquid while removing the old, which can be recharged and used again. This means that electric vehicles could be recharged in times comparable to filling a tank of gasoline, and two differently fueled vehicles could use the same pump. The system can also provide both electricity and hydrogen fuel in situations that require a large degree of flexibility, including in emergencies or remote locations.
"For future renewables to be effective high capacity and flexible energy storage systems are needed to smooth out the peaks and troughs in supply" says Cronin. "Our approach will provide a new route to do this electrochemically and could even have application in electric cars where batteries can still take hours to recharge and have limited capacity. Moreover, the very high energy density of our material could increase the range of electric cars, and also increase the resilience of energy storage systems to keep the lights on at times of peak demand."
The research was published in Nature Chemistry.
Source: University of Glasgow