Generating renewable energy is just one side of the coin, while the other being the ability to store all that energy. Since utilities aren’t able to produce renewable energy continuously, as the sun doesn’t shine all day, nor does the wind blow throughout the day, energy storage solutions are high in demand. A team of researchers at the Georgia Institute of Technology have come up with a prototype lithium cell, which not only stores energy, but generates it too.
The self-charging cell is actually a coin-type lithium-ion cell in which the polyethylene separator is replaced by a PVDF film. PVDF is a piezoelectric material, which generates a charge when under stress. The same charge is stored in the lithium ion cell, which makes the battery self-charging.
To induce stress, the research team is starting with attaching the coin shaped battery to the bottom of a shoe, whereby the wearer can generate a charge while walking or running. Though, the compressive force of 2.3Hz could increase the voltage of the device from 327 to 395mV in four minutes, the device could serve as a stepping stone for large-scale energy harvesting systems that don’t need additional energy storage infrastructure.