Engineering

Silicon-Air Batteries made for 1000 hours

A battery, which is fivefold the range of electric cars, is now within reach. Researchers at Jülich have eliminated a crucial obstacle to the day-to-day operation of a such high-performance battery, which is also still unrivalled cheap.

Batteries, whose electrodes consist air and silicon, save five times more power than conventional lithium-ion batteries. In addition, they contain carbon, a little nickel, that loud very Teflon known polytetrafluoroethylene, potassium hydroxide and water, as a frying pan coating cheap raw materials, which are also in abundance available. In electric cars, laptops or Smartphones you are looking for they despite their superior storage density, which would reach fivefold. Because they have a decisive Macke: after a few dozen hours they no longer release the stored energy.

Starting on the wrong track

At Research Centre Jülich (FZJ), a only button cell large Silicon-air battery has now set up a memorable record. It runs for more than 1000 hours, without that willingness to return the stored power, would have suffered.

Initially, the FZJ energy and Climate Research Institute researchers tried protecting the Silicon anode against corrosion because they suspected it was the cause for the short-lived. They experimented with different electrolytes, which are liquids, which are located between the electrodes (anode and cathode), and modified the porous layer through which oxygen penetrates into the battery.

Silicon-Air Batteries for 1000 hours

Only when they put a ionic liquids, specialty salts, which are liquid at room temperature, researchers observed an improvement. Thus they aim is to develop a low-cost battery with ionic liquids as very expensive materials.

A small pump brought the breakthrough

Then they had the idea of saving. They suspected the electrolyte-potassium hydroxide dissolved in water will consume when loading and unloading the battery so that it was discontinuing the operation after a while. For this reason, they added a pump, fed up from time to time fresh electrolyte. “Remains the Silicon anode in contact with the electrolyte, the battery runs”, so the realization of Hermann Temple, one of the researchers involved.

Regardless, the Silicon in the course of time degrades itself so that the anode must be replaced from time to time.

The battery is still not always suitable for use in everyday life. Users certainly have no desire to replace the anode every couple of weeks and to top up electrolyte fluid. Temple sees this as: “the battery is still not perfect, but now we know what we need to work on.”