Electric car batteries that refuel at the pump in minutes

The days of waiting eight hours for an electric car to recharge could soon be a thing of the past. A team of researchers from MIT in America that set out to “reinvent the rechargeable battery” has developed a new approach to energy storage that could revolutionize the cars we drive.

Electric cars take up to eight hours to recharge, but the new approach to battery design make “refuelling” such vehicles as quick and straightforward as filling up at the pumps with a conventional car.

So-called flow batteries have existed for some time, but according to MIT, the new battery relies on a semi-solid flow cell, in which solid particles are suspended in a carrier liquid and pumped through the system. In this design, the battery’s active components — the positive and negative electrodes, or cathodes and anodes — are composed of particles suspended in a liquid electrolyte. These two different suspensions are pumped through systems separated by a filter, such as a thin porous membrane.

The researchers are confident that the new design should make it possible to reduce the size and the cost of a complete battery system to half the current levels. The resulting reduction in cost would play an important role in helping electric vehicles to be more competitive.

The most noticeable aspect of the new system is that in vehicle applications, an electric vehicle in need of recharging would refuel its battery by pumping out the liquid slurry and pumping in a fresh, fully charged replacement – much like a conventional car is filled with petrol at the pump.

The new technology is being licensed to a company called 24M Technologies. The company has already raised more than $16 million in venture capital and federal research funding.

A spokesperson for the Environmental Transport Association (ETA) said: “Battery technology is advancing quickly and the work at MIT can only hasten the move towards electric vehicles.”