Concrete is considered the most common building material in the world, and at the same time it causes serious harm to the environment. Cement – the main ingredient in concrete – is the second largest industrial carbon source on the planet. Cement production alone accounts for up to 7% of CO₂ emissions in the world atmosphere.
To make concrete cleaner, scientists have developed the world’s first cement-based battery concept. As you know, batteries can not only store energy, but also act as structural components. Scientists in Sweden have taken this idea to design buildings that will store energy.
The concept first includes a cement-based mix with a small amount of short carbon fibers to increase conductivity and strength. Then a metal-coated carbon fiber mesh was built into the mixture – iron for the anode and nickel for the cathode. Recall that the electrode of a semiconductor device (diode, thyristor) connected to the negative pole of the current source when the device is open (that is, has a small resistance) is called the cathode, connected to the positive pole – the anode.
It turned out that such a concrete-based battery has an energy density of 7 Wh per square meter of material, which is 10 times more than previous energy storage devices made of concrete.