A research team and the Georgia Institute of Technology has invented a lithium ion battery that charges itself by using the environment vibrations. Unlike other similar devices, this one is highly efficient, because it converts mechanical energy to chemical energy directly, without using electricity as a middleman.
A piezoelectric membrane is at the Lithium Cobalt Oxide battery’s core, driving lithium ions from one side of the cell to the other when mechanical stress is applied.
This way, the mechanical energy is directly converted into potential stored chemically. The cathode is made from lithium cobalt oxide (LiCO2) and the anode from titanium dioxide (TiO2) nanotubes grown on top of a titanium film.
The piezoelectric part is played by a vinylidene fluoride film, generating ion movement when strained.
The scientists have so far only made batteries the size of a coin that could only fuel small power devices such as sensors and low-consumption microprocessors. This could be of help to soldiers who could actually forget about some of the equipment they carry, which could get powered by these cells carried in the soles of their boots.